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Sample records for 30-amino acid synthetic

  1. A new synthetic protocol for coumarin amino acid

    Xinyi Xu; Xiaosong Hu; Jiangyun Wang

    2013-01-01

    The hydrochloride of the racemic amino acid (2-(7-hydroxycoumarin-4-yl)ethyl)glycine, which can serve as a fluorescent probe in proteins, and two halogen derivatives of it, were synthesized by using a new synthetic protocol in five steps. It is less costly and relatively easy to prepare this kind of fluorescent amino acid with the new synthetic method. Furthermore, it can be applied to synthesize other derivatives of the coumarin amino acid with some specific properties.

  2. Non-natural Nucleic Acids for Synthetic Biology

    Appella, Daniel H.

    2009-01-01

    Genetic manipulation is an important facet of synthetic biology but can be complicated by undesired nuclease degradation. Incorporating non-natural nucleic acids into a gene could convey resistance to nucleases and promote expression. The compatibility of non-natural nucleosides with polymerases is reviewed with a focus on results from the past two years. Details are provided about how the different systems could be useful in synthetic biology.

  3. Synthetic Fatty Acids Prevent Plasmid-Mediated Horizontal Gene Transfer

    Getino Redondo, María; Sanabria Ríos, David J.; Fernández López, Raúl; Campos Gómez, Javier; Sánchez López, José M.; Fernández Medarde, Antonio; Carballeira Cabranes, Néstor M.; Cruz Calahorra, Fernando de la

    2015-01-01

    Bacterial conjugation constitutes a major horizontal gene transfer mechanism for the dissemination of antibiotic resistance genes among human pathogens. Antibiotic resistance spread could be halted or diminished by molecules that interfere with the conjugation process. In this work, synthetic 2-alkynoic fatty acids were identified as a novel class of conjugation inhibitors. Their chemical properties were investigated by using the prototype 2-hexadecynoic acid and its derivatives. Essential fe...

  4. Biotin synthesis begins by hijacking the fatty acid synthetic pathway.

    Lin, Steven; Hanson, Ryan E; Cronan, John E

    2010-09-01

    Although biotin is an essential enzyme cofactor found in all three domains of life, our knowledge of its biosynthesis remains fragmentary. Most of the carbon atoms of biotin are derived from pimelic acid, a seven-carbon dicarboxylic acid, but the mechanism whereby this intermediate is assembled remains unknown. Genetic analysis in Escherichia coli identified only two genes of unknown function required for pimelate synthesis, bioC and bioH. We report in vivo and in vitro evidence that the pimeloyl moiety is synthesized by a modified fatty acid synthetic pathway in which the omega-carboxyl group of a malonyl-thioester is methylated by BioC, which allows recognition of this atypical substrate by the fatty acid synthetic enzymes. The malonyl-thioester methyl ester enters fatty acid synthesis as the primer and undergoes two reiterations of the fatty acid elongation cycle to give pimeloyl-acyl carrier protein (ACP) methyl ester, which is hydrolyzed to pimeloyl-ACP and methanol by BioH. PMID:20693992

  5. Recoded organisms engineered to depend on synthetic amino acids.

    Rovner, Alexis J; Haimovich, Adrian D; Katz, Spencer R; Li, Zhe; Grome, Michael W; Gassaway, Brandon M; Amiram, Miriam; Patel, Jaymin R; Gallagher, Ryan R; Rinehart, Jesse; Isaacs, Farren J

    2015-02-01

    Genetically modified organisms (GMOs) are increasingly used in research and industrial systems to produce high-value pharmaceuticals, fuels and chemicals. Genetic isolation and intrinsic biocontainment would provide essential biosafety measures to secure these closed systems and enable safe applications of GMOs in open systems, which include bioremediation and probiotics. Although safeguards have been designed to control cell growth by essential gene regulation, inducible toxin switches and engineered auxotrophies, these approaches are compromised by cross-feeding of essential metabolites, leaked expression of essential genes, or genetic mutations. Here we describe the construction of a series of genomically recoded organisms (GROs) whose growth is restricted by the expression of multiple essential genes that depend on exogenously supplied synthetic amino acids (sAAs). We introduced a Methanocaldococcus jannaschii tRNA:aminoacyl-tRNA synthetase pair into the chromosome of a GRO derived from Escherichia coli that lacks all TAG codons and release factor 1, endowing this organism with the orthogonal translational components to convert TAG into a dedicated sense codon for sAAs. Using multiplex automated genome engineering, we introduced in-frame TAG codons into 22 essential genes, linking their expression to the incorporation of synthetic phenylalanine-derived amino acids. Of the 60 sAA-dependent variants isolated, a notable strain harbouring three TAG codons in conserved functional residues of MurG, DnaA and SerS and containing targeted tRNA deletions maintained robust growth and exhibited undetectable escape frequencies upon culturing ∼10(11) cells on solid media for 7 days or in liquid media for 20 days. This is a significant improvement over existing biocontainment approaches. We constructed synthetic auxotrophs dependent on sAAs that were not rescued by cross-feeding in environmental growth assays. These auxotrophic GROs possess alternative genetic codes that

  6. Macroporous Biodegradable Cryogels of Synthetic Poly(α-amino acids).

    Sedlačík, Tomáš; Proks, Vladimír; Šlouf, Miroslav; Dušková-Smrčková, Miroslava; Studenovská, Hana; Rypáček, František

    2015-11-01

    We present an investigation of the preparation of highly porous hydrogels based on biodegradable synthetic poly(α-amino acid) as potential tissue engineering scaffolds. Covalently cross-linked gels with permanent pores were formed under cryogenic conditions by free-radical copolymerization of poly[N(5)-(2-hydroxyethyl)-L-glutamine-stat-N(5)-(2-methacryloyl-oxy-ethyl)-L-glutamine] (PHEG-MA) with 2-hydrohyethyl methacrylate (HEMA) and, optionally, N-propargyl acrylamide (PrAAm) as minor comonomers. The morphology of the cryogels showed interconnected polyhedral or laminar pores. The volume content of communicating water-filled pores was >90%. The storage moduli of the swollen cryogels were in the range of 1-6 kPa, even when the water content was >95%. The enzymatic degradation of a cryogel corresponded to the decrease in its storage modulus during incubation with papain, a model enzyme with specificity analogous to wound-healing enzymes. It was shown that cryogels with incorporated alkyne groups can easily be modified with short synthetic peptides using azide-alkyne cycloaddition "click" chemistry, thus providing porous hydrogel scaffolds with biomimetic features. PMID:26474357

  7. Carnosic acid biosynthesis elucidated by a synthetic biology platform.

    Ignea, Codruta; Athanasakoglou, Anastasia; Ioannou, Efstathia; Georgantea, Panagiota; Trikka, Fotini A; Loupassaki, Sofia; Roussis, Vassilios; Makris, Antonios M; Kampranis, Sotirios C

    2016-03-29

    Synthetic biology approaches achieving the reconstruction of specific plant natural product biosynthetic pathways in dedicated microbial "chassis" have provided access to important industrial compounds (e.g., artemisinin, resveratrol, vanillin). However, the potential of such production systems to facilitate elucidation of plant biosynthetic pathways has been underexplored. Here we report on the application of a modular terpene production platform in the characterization of the biosynthetic pathway leading to the potent antioxidant carnosic acid and related diterpenes in Salvia pomifera and Rosmarinus officinalis.Four cytochrome P450 enzymes are identified (CYP76AH24, CYP71BE52, CYP76AK6, and CYP76AK8), the combined activities of which account for all of the oxidation events leading to the biosynthesis of the major diterpenes produced in these plants. This approach develops yeast as an efficient tool to harness the biotechnological potential of the numerous sequencing datasets that are increasingly becoming available through transcriptomic or genomic studies. PMID:26976595

  8. Morphology and thermal degradation study of poly(lactic acid)/synthetic mica composites

    Poly(lactic acid) (PLA)/synthetic mica composites has been little studied in the literature. In this work, an organophilic synthetic mica was used to prepare PLA nanocomposites. The composites were obtained at an internal mixer containing 3, 5, 7 and 10 wt% of mica. The materials were analyzed by x-ray diffraction, thermogravimetric analysis and gel permeation chromatography. (author)

  9. Rapid access to synthetic lysobisphosphatidic acids using P(III) chemistry.

    Chevallier, J; Sakai, N; Robert, F; Kobayashi, T; Gruenberg, J; Matile, S

    2000-06-29

    An expeditious route to synthetic lysobisphosphatidic acid S,S-1, its enantiomer, and regioisomers is reported. Synthetic difficulties concerning lipid stability and stereochemistry are bypassed using a phosphite triester approach in combination with multiple silyl protection. Spectroscopic studies evidence that acyl group migration in S,S-1 is accelerated by nonpolar solvents and inhibited by pyridine. PMID:10891176

  10. Obeticholic acid, a synthetic bile acid agonist of the farnesoid X receptor, attenuates experimental autoimmune encephalomyelitis.

    Ho, Peggy P; Steinman, Lawrence

    2016-02-01

    Bile acids are ligands for the nuclear hormone receptor, farnesoid X receptor (FXR). The bile acid-FXR interaction regulates bile acid synthesis, transport, and cholesterol metabolism. Recently, bile acid-FXR regulation has been reported to play an integral role in both hepatic and intestinal inflammation, and in atherosclerosis. In this study, we found that FXR knockout mice had more disease severity in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Obeticholic acid (6α-ethyl-chenodeoxycholic acid, 6-ECDCA), a synthetic FXR agonist, is an orally available drug that is currently in clinical trials for the treatment of inflammatory diseases such as alcoholic hepatitis, nonalcoholic steatohepatitis, and primary biliary cirrhosis. When we treated mice exhibiting established EAE with 6-ECDCA, or the natural FXR ligand chenodeoxycholic acid (CDCA), clinical disease was ameliorated by (i) suppressing lymphocyte activation and proinflammatory cytokine production; (ii) reducing CD4(+) T cells and CD19(+) B cell populations and their expression of negative checkpoint regulators programmed cell death protein 1 (PD1), programmed death-ligand 1 (PD-L1), and B and T lymphocyte attenuator (BTLA); (iii) increasing CD8(+) T cells and PD1, PDl-1, and BTLA expression; and (iv) reducing VLA-4 expression in both the T- and B-cell populations. Moreover, adoptive transfer of 6-ECDCA- or CDCA-treated donor cells failed to transfer disease in naive recipients. Thus, we show that FXR functions as a negative regulator in neuroinflammation and we highlight that FXR agonists represent a potential previously unidentified therapy for MS. PMID:26811456

  11. Synthetic

    Anna Maria Manferdini

    2010-06-01

    Full Text Available Traditionally materials have been associated with a series of physical properties that can be used as inputs to production and manufacturing. Recently we witnessed an interest in materials considered not only as ‘true matter’, but also as new breeds where geometry, texture, tooling and finish are able to provoke new sensations when they are applied to a substance. These artificial materials can be described as synthetic because they are the outcome of various qualities that are not necessarily true to the original matter, but they are the combination of two or more parts, whether by design or by natural processes. The aim of this paper is to investigate the potential of architectural surfaces to produce effects through the invention of new breeds of artificial matter, using micro-scale details derived from Nature as an inspiration.

  12. Natural cinnamic acids, synthetic derivatives and hybrids with antimicrobial activity.

    Guzman, Juan David

    2014-01-01

    Antimicrobial natural preparations involving cinnamon, storax and propolis have been long used topically for treating infections. Cinnamic acids and related molecules are partly responsible for the therapeutic effects observed in these preparations. Most of the cinnamic acids, their esters, amides, aldehydes and alcohols, show significant growth inhibition against one or several bacterial and fungal species. Of particular interest is the potent antitubercular activity observed for some of these cinnamic derivatives, which may be amenable as future drugs for treating tuberculosis. This review intends to summarize the literature data on the antimicrobial activity of the natural cinnamic acids and related derivatives. In addition, selected hybrids between cinnamic acids and biologically active scaffolds with antimicrobial activity were also included. A comprehensive literature search was performed collating the minimum inhibitory concentration (MIC) of each cinnamic acid or derivative against the reported microorganisms. The MIC data allows the relative comparison between series of molecules and the derivation of structure-activity relationships. PMID:25429559

  13. Natural Cinnamic Acids, Synthetic Derivatives and Hybrids with Antimicrobial Activity

    Juan David Guzman

    2014-11-01

    Full Text Available Antimicrobial natural preparations involving cinnamon, storax and propolis have been long used topically for treating infections. Cinnamic acids and related molecules are partly responsible for the therapeutic effects observed in these preparations. Most of the cinnamic acids, their esters, amides, aldehydes and alcohols, show significant growth inhibition against one or several bacterial and fungal species. Of particular interest is the potent antitubercular activity observed for some of these cinnamic derivatives, which may be amenable as future drugs for treating tuberculosis. This review intends to summarize the literature data on the antimicrobial activity of the natural cinnamic acids and related derivatives. In addition, selected hybrids between cinnamic acids and biologically active scaffolds with antimicrobial activity were also included. A comprehensive literature search was performed collating the minimum inhibitory concentration (MIC of each cinnamic acid or derivative against the reported microorganisms. The MIC data allows the relative comparison between series of molecules and the derivation of structure-activity relationships.

  14. An Efficient Synthetic Method of Nordihydroguaiaretic Acid (NDGA)

    2003-01-01

    Nordihydroguaiaretic acid (NDGA) has been synthesized in nine steps from piperonal using Stobbe condensation as the key step with high yield. By this approach, five relative natural products were obtained.

  15. Biotin Synthesis Begins by Hijacking the Fatty Acid Synthetic Pathway

    Lin, Steven; Hanson, Ryan E.; Cronan, John E.

    2010-01-01

    Although biotin is an essential enzyme cofactor found in all three domains of life, our knowledge of its biosynthesis remains fragmentary. Most of the carbon atoms of biotin are derived from pimelic acid, a seven carbon dicarboxylic acid, but the mechanism whereby Escherichia coli assembles this intermediate remains unknown. Genetic analysis identified only two genes of unknown function required for pimelate synthesis, bioC and bioH. We report in vivo and in vitro evidence that the pimeloyl m...

  16. [Volatile fatty acids in the rumen of sheep fed a synthetic diet].

    Baran, M; Bod'a, K; Jalc, D; Piatková, M; Kalacnjuk, G I; Várady, J

    1983-08-01

    A trial was conducted with wethers to study the effect of the administration of a synthetic diet (composition: 30.125% starch, 30.125% sucrose, 25% cellulose, 5.25% urea, 8.125% mineral supplement, 1.25% maize oil and 0.125% cholinechloride) upon rumen fermentation. The adaptation to the synthetic diet lasted three months, the proportion of the synthetic diet increasing every week (by 10%) to the detriment of a traditional diet (composition: 0.5 kg meadow hay, 0.3 kg barley, 0.2 kg wheat bran, salt and straw ad libitum). In the 10th week the animals consumed 0.5 kg granular synthetic diet, 0.2 kg cellulose flakes and 0.01 kg polystyrene. After three weeks of the administration of the fully synthetic diet, the rumen fluid was sampled after morning feeding in intervals of 0, 1, 3, 5 and 7 hours. In the dynamics of fermentation, statistically significant differences were found only in isobutyric and isovaleric acid between the 0th and 1st and between the 5th and 7th hours (P less than 0.05--P less than 0.001). The data for all the time intervals were recalculated to average values. These were as follows: total volatile fatty acids 63.03 mmol/l, acetic acid 51.00 mol%, propionic acid 26.75 mol%, butyric acid 19.43 mol%, isobutyric acid 0.91 mol%, isovaleric 1.27 mol%, valeric acid 0.62 mol%, energy efficiency of VFA production 78.23%. The obtained data are confronted with literary data on synthetic diets which contained urea and various energy sources. PMID:6414150

  17. Interaction of americium (III) with humic acids and two synthetic analogues

    In this paper, a recent series of studies on complexation of Am3+ with humic acids and some analogues are summarized and the experimental procedures and method for data analysis applied are presented. The samples are: LBHA(mud-derived humic acid), BHA (humic acid from coastal marine sediments), ALHA (commercial humic acid), SHA (synthetic humic acid), and PMA (poly(maleic) acid). LBHA is the most extensively studied for actinide binding of this group of ligands. Comparison is made of the metal-binding properties of the BHA and ALHA humic acids with those of LBHA to learn the applicability of the results for a particular humic acid, LBHA, to others of different origin. SHA and PMA are often employed in metal-binding and other studies as analogues of natural humic acid. These analogues have a more regular structure and their data may be easier to interpret. Optical spectroscopy, potentiometric titration, and solvent extraction are used in the investigations. The present study supports with qualifications the similarity in actinide binding by humic acids of different origin. It has also indicated that the synthetic humic acid is a suitable analog of natural humic acids for actinide binding studies while PMA more closely mimics a fulvic acid. (N.K.)

  18. Carnosic acid biosynthesis elucidated by a synthetic biology platform

    Ignea, Codruta; Athanasakoglou, Anastasia; Ioannou, Efstathia; Georgantea, Panagiota; Trikka, Fotini A; Loupassaki, Sofia; Roussis, Vassilios; Makris, Antonios M; Kampranis, Sotirios C

    2016-01-01

    facilitate elucidation of plant biosynthetic pathways has been underexplored. Here we report on the application of a modular terpene production platform in the characterization of the biosynthetic pathway leading to the potent antioxidant carnosic acid and related diterpenes in Salvia pomifera and Rosmarinus...

  19. Microbial production of amino acids and derived chemicals: synthetic biology approaches to strain development.

    Wendisch, Volker F

    2014-12-01

    Amino acids are produced at the multi-million-ton-scale with fermentative production of l-glutamate and l-lysine alone being estimated to amount to more than five million tons in the year 2013. Metabolic engineering constantly improves productivities of amino acid producing strains, mainly Corynebacterium glutamicum and Escherichia coli strains. Classical mutagenesis and screening have been accelerated by combination with intracellular metabolite sensing. Synthetic biology approaches have allowed access to new carbon sources to realize a flexible feedstock concept. Moreover, new pathways for amino acid production as well as fermentative production of non-native compounds derived from amino acids or their metabolic precursors were developed. These include dipeptides, α,ω-diamines, α,ω-diacids, keto acids, acetylated amino acids and ω-amino acids. PMID:24922334

  20. Plant Proteins and Synthetic Amino Acids in the Nutrition of Non-Ruminants

    It is to be emphasized that in formulating diets for farm animals other than ruminants it is important to meet the requirements for individual essential amino acids and not merely to give regard to over-ail protein quality. The protein component serves to meet the needs for essential amino acids and also supplies material to synthesize those amino acids that are individually dispensable. In arranging for efficient formulation it is important to have available amino acid requirement standards to meet a particular production objective and data on the quantity of amino acids supplied by the various ingredients available. In considering the amino acid content of ingredients it is important to pay due regard to the problems of availability. Efforts to define amino acid requirements for the pig and chick have given somewhat variable results: it is possible to account for some of this variability. It is recognized that under certain circumstances non-amino nitrogen can be utilized by such species as the chick and the pig. The mechanisms involved are briefly considered. Some experimental work has shown that non-amino nitrogen can support growth, but it is difficult to establish a situation in which the non-essential amino acid levels are sufficiently low to take advantage of this fact. Extensive use of synthetic essential amino acids could change this situation. The case for the use of synthetic amino acids in the diets of farm animals is essentially an economic one. It is no longer necessary to demonstrate that free dietary amino acids can meet the needs of the animal. The only question is whether the needs of the animal are more effectively met by the addition of amino acids or more intact protein. The place of alternative protein sources to such attractive commodities as fish meal or soyabean meal must be considered in terms of amino acid supply. Whilst synthetic methionine and lysine are available there is a developing case for the use of such products as sunflower

  1. Novel ferulic acid esterases from Bifidobacterium sp. produced on selected synthetic and natural carbon sources

    Dominik Szwajgier

    2010-09-01

    Full Text Available Background. Ferulic acid esterases (or feruloyl esterases, a common group of hydrolases are very well distributed in the plant kongdom. The fungal feruloyl esterases were very extensively studied whereas probiotic lactic acid bacteria as the source of this enzyme were generally omitted. Free phenolic acids – strong antioxidants can be released from the dietary fiber by the action of intestinal lactic acid bacteria. The aim of this study was to examine the three probiotic Bifidobacterium strains to produce extracellular FAE on different synthetic and natural carbon sources. Material and methods. Studies were carried out using Bifidibacteriumstrains (B. animalis Bi30, B. catenulatum KD 14 and B. longum KN 29. The strains were cultivated using minimal growth media containing selected natural and synthetic carbon sources: German wheat bran, rye bran, barley spent grain, isolated larchwood arabinogalactan, apple pectin, corn pectin, methyl esters of phenolic acids. The production of extracellular feruloyl esterase was estimated using the post cultivation supernatants and methyl ferulate. The concentration of ferulic acid released from the ester was determined using HPLC with DAD detection. Results. The most efficient bacterial strain for FAE production was B. animalis cultivated in the presence of methyl p-coumarate and methyl ferulate as the main carbon sources (14.95 nmol·ml-1·min-1 and 4.38 nmol·ml-1·min-1, respectively. In the case of each FAE, the highest activity was obtained at 37oC (pH 6.3 in Theorell/Steinhagen buffer (B. animalis Bi30 or in Tris/HCl buffer (B. catenulatum KD14 and B. longum KN29. Taking under consideration all results, it should be noticed that the highest feruloyl esterase activities were obtained using synthetic methyl esters of phenolic acids. Conclusions. The presented resultsbroaden the knowledgeabout the production of the feruloyl esterase by probiotic bacteria. Although the enzyme is only accessory during

  2. Synthetic Biolubricant Basestocks from Epoxidized Ricinoleic Acid: Improved Low Temperature Properties

    Yousif, E.

    2011-03-01

    Full Text Available This paper presents a series of structural modifications of epoxidized ricinoleic acid for biolubricant to improve the cold flow behavior and oxidation stability of vegetable oils through measurement of pour point (PP and oxidation onset temperature (OT and signal maximum temperature (SMT of each synthetic compound. The results showed that butyl 10,12-dihydroxy-9-behenoxystearate with bulky ester behenyl mid-chain exhibited the most favorable low-temperature performance ϑPP=– 47 °C. On the other hand, butyl 10,12-dihydroxy-9-octyloxystearate exhibited higher oxidation stability (ϑOT = 221 °C than the other synthetic esters. It was discovered that increasing chain length of the mid-chain ester had a positive influence on the low temperature properties of synthesized compounds. Improved oxidation stability is achieved when the chain length of the mid-chain ester decreases. The synthesized ester structures were confirmed by NMR and FTIR analysis.

  3. Obeticholic acid, a synthetic bile acid agonist of the farnesoid X receptor, attenuates experimental autoimmune encephalomyelitis

    Peggy P. Ho; Steinman, Lawrence

    2016-01-01

    Bile acids bind to the nuclear hormone receptor, farnesoid X receptor (FXR). This bile acid–FXR interaction regulates bile acid synthesis, transport, and cholesterol metabolism. Recently, drugs targeting FXR activation have been reported to treat both liver and intestinal inflammatory diseases in both animal models and human clinical trials. Experimental autoimmune encephalomyelitis (EAE) is an inflammatory demyelinating disease of the central nervous system and serves as an animal model for ...

  4. Acetic Acid Detection Threshold in Synthetic Wine Samples of a Portable Electronic Nose

    Miguel Macías Macías

    2012-12-01

    Full Text Available Wine quality is related to its intrinsic visual, taste, or aroma characteristics and is reflected in the price paid for that wine. One of the most important wine faults is the excessive concentration of acetic acid which can cause a wine to take on vinegar aromas and reduce its varietal character. Thereby it is very important for the wine industry to have methods, like electronic noses, for real-time monitoring the excessive concentration of acetic acid in wines. However, aroma characterization of alcoholic beverages with sensor array electronic noses is a difficult challenge due to the masking effect of ethanol. In this work, in order to detect the presence of acetic acid in synthetic wine samples (aqueous ethanol solution at 10% v/v we use a detection unit which consists of a commercial electronic nose and a HSS32 auto sampler, in combination with a neural network classifier (MLP. To find the characteristic vector representative of the sample that we want to classify, first we select the sensors, and the section of the sensors response curves, where the probability of detecting the presence of acetic acid will be higher, and then we apply Principal Component Analysis (PCA such that each sensor response curve is represented by the coefficients of its first principal components. Results show that the PEN3 electronic nose is able to detect and discriminate wine samples doped with acetic acid in concentrations equal or greater than 2 g/L.

  5. Synthetic studies of coumarin derivatives from o-hydroxybenzophenones with phenylacetic acid and acetic anhydride

    Kang, Soon Hee; Yang, Sung Yun [Ewha Womans Univ., Seoul (Korea, Republic of)

    1999-02-01

    The 8 coumarin derivatives have been synthesized from 8 starting materials(2-hydroxy-benzophenone, 2,2'-dihydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-5-methylbenzophenone, 5-chloro-2-hydroxy-4-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-4'-dimethoxybenzophenone) with phenylacetic acid and Ac{sub 2}O/TEA in acetone at reflux temperature. The ratio of o-hydroxybenzophenone, phenylacetic acid, Ac{sub 2}O and TEA is 1:1:8:8 in acetone. Our results showed higher products yields of coumarin derivatives than Shama and Ray's method in previous papers. A new intermediate form was proposed to our mechanism of coumarin synthetic method.

  6. Bioassessment of a combined chemical-biological treatment for synthetic acid mine drainage.

    Pagnanelli, F; De Michelis, I; Di Muzio, S; Ferella, F; Vegliò, F

    2008-11-30

    In this work, ecotoxicological characteristics of synthetic samples of acid mine drainage (AMD) before and after a combined chemical-biological treatment were investigated by using Lepidium sativum and Daphnia magna. AMD treatment was performed in a two-column apparatus consisting of chemical precipitation by limestone and biological refinement by sulphate reducing bacteria. Synthetic samples of AMD before treatment were toxic for both L. sativum (germination index, G, lower than 10%) and D. magna (100% immobility) due to acid pH and presence of copper and zinc. Chemical treatment (raising pH to 5-6 and eliminating copper) generated effluents with reduced toxicity for L. sativum (G=33%), while 100% immobility was still observed for D. magna. Dynamic trends of toxicity for the first and fifth outputs of the biological column denoted a gradual improvement leading to hormesis for Lepidium (after the initial release of organic excess), while a constant residual toxicity remained for Daphnia (probably due to H(2)S produced by sulphate reducing bacteria). PMID:18394799

  7. The pattern recognition molecule deleted in malignant brain tumors 1 (DMBT1) and synthetic mimics inhibit liposomal nucleic acid delivery

    Lund Hansen, Pernille; Blaich, Stephanie; End, Caroline; Schmidt, Steffen; Møller, Jesper Bonnet; Holmskov, Uffe; Mollenhauer, Jan

    2011-01-01

    Liposomal nucleic acid delivery is a preferred option for therapeutic settings. The cellular pattern recognition molecule DMBT1, secreted at high levels in various diseases, and synthetic mimics efficiently inhibit liposomal nucleic acid delivery to human cells. These findings may have relevance ...

  8. Toxicity of synthetic naphthenic acids and mixtures of these to fish liver cells.

    Tollefsen, Knut Erik; Petersen, Karina; Rowland, Steven J

    2012-05-01

    Environmental concerns have been raised over the toxicity of crude naphthenic acids (NA) originating from oil exploration activities offshore, oil sands exploitation onshore, and use of refined NA as wood preservatives, tire additives, and in various other applications. The NA exist in highly complex mixtures, so the toxic effects of the individual acids are rarely known. The present study investigated the relationships between the chemical structures of a range of synthetic alicyclic and aromatic acids and their acute toxicities both as single chemicals and as complex mixtures in a primary culture of rainbow trout (Oncorhynchus mykiss) hepatocytes. The combined toxicity of multicomponent mixtures of these NA was assessed using the concept of concentration addition (CA) and independent action (IA) prediction. All of the acids tested were moderately toxic, with EC(50) values in the range 108-405 μM (24-89 mg L(-1)) and 188-656 μM (43-148 mg L(-1)) when assessed by effects on metabolic inhibition or loss of membrane integrity, respectively. Binary and 6-compound mixture of NA caused combined toxicity according to the concept of additivity, although slight deviations from additivity were observed at a few mixture concentrations. Single NA and mixtures of NA with similar structures to those tested herein probably contribute to the toxicity of complex natural mixtures of NA. Toxicity tests on three commercial NA mixtures showed that these exhibited highly variable toxicities themselves probably reflecting their chemical heterogeneity. PMID:22462822

  9. Magnetic microparticles post-synthetically coated by hyaluronic acid as an enhanced carrier for microfluidic bioanalysis

    Holubova, Lucie [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Knotek, Petr [Joint Laboratory of Solid State Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Palarcik, Jiri [Institute of Environmental and Chemical Engineering, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Cadkova, Michaela [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Belina, Petr [Department of Inorganic Technology, Faculty of Chemical Technology, University of Pardubice, Doubravice 41, 53210 Pardubice (Czech Republic); Vlcek, Milan [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovskeho sq. 2, 16206 Prague (Czech Republic); Korecka, Lucie [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Bilkova, Zuzana, E-mail: Zuzana.Bilkova@upce.cz [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic)

    2014-11-01

    Iron oxide based particles functionalized by bioactive molecules have been utilized extensively in biotechnology and biomedicine. Despite their already proven advantages, instability under changing reaction conditions, non-specific sorption of biomolecules on the particles' surfaces, and iron oxide leakage from the naked particles can greatly limit their application. As confirmed many times, surface treatment with an appropriate stabilizer helps to minimize these disadvantages. In this work, we describe enhanced post-synthetic surface modification of superparamagnetic microparticles varying in materials and size using hyaluronic acid (HA) in various chain lengths. Scanning electron microscopy, atomic force microscopy, phase analysis light scattering and laser diffraction are the methods used for characterization of HA-coated particles. The zeta potential and thickness of HA-layer of HA-coated Dynabeads M270 Amine were − 50 mV and 85 nm, respectively, and of HA-coated p(GMA-MOEAA)-NH{sub 2} were − 38 mV and 140 nm, respectively. The electrochemical analysis confirmed the zero leakage of magnetic material and no reactivity of particles with hydrogen peroxide. The rate of non-specific sorption of bovine serum albumin was reduced up to 50% of the naked ones. The coating efficiency and suitability of biopolymer-based microparticles for magnetically active microfluidic devices were confirmed. - Highlights: • Post-synthetic surface modification of magnetic microparticles by hyaluronic acid • Hyaluronic acid — polymer of unique physicochemical and biological characteristics • Panel of particle characterization methods was introduced. • HA-coated microparticles gain characteristics suited for microfluidic bioanalysis.

  10. Magnetic microparticles post-synthetically coated by hyaluronic acid as an enhanced carrier for microfluidic bioanalysis

    Iron oxide based particles functionalized by bioactive molecules have been utilized extensively in biotechnology and biomedicine. Despite their already proven advantages, instability under changing reaction conditions, non-specific sorption of biomolecules on the particles' surfaces, and iron oxide leakage from the naked particles can greatly limit their application. As confirmed many times, surface treatment with an appropriate stabilizer helps to minimize these disadvantages. In this work, we describe enhanced post-synthetic surface modification of superparamagnetic microparticles varying in materials and size using hyaluronic acid (HA) in various chain lengths. Scanning electron microscopy, atomic force microscopy, phase analysis light scattering and laser diffraction are the methods used for characterization of HA-coated particles. The zeta potential and thickness of HA-layer of HA-coated Dynabeads M270 Amine were − 50 mV and 85 nm, respectively, and of HA-coated p(GMA-MOEAA)-NH2 were − 38 mV and 140 nm, respectively. The electrochemical analysis confirmed the zero leakage of magnetic material and no reactivity of particles with hydrogen peroxide. The rate of non-specific sorption of bovine serum albumin was reduced up to 50% of the naked ones. The coating efficiency and suitability of biopolymer-based microparticles for magnetically active microfluidic devices were confirmed. - Highlights: • Post-synthetic surface modification of magnetic microparticles by hyaluronic acid • Hyaluronic acid — polymer of unique physicochemical and biological characteristics • Panel of particle characterization methods was introduced. • HA-coated microparticles gain characteristics suited for microfluidic bioanalysis

  11. Production of extracellular ferulic acid esterases by Lactobacillus strains using natural and synthetic carbon sources

    Dominik Szwajgier

    2011-09-01

    Full Text Available Background. Ferulic acid esterases (FAE, EC 3.1.1.73, also known as feruloyl esterases, cinnamic acid esterases or cinnamoyl esterases, belong to a common group of hydrolases distributed in the plant kingdom. Especially the fungal enzymes were very well characterised in the past whereas the enzyme was rarely found in the lactic acid bacteria (LAB strains. It is well known that strong antioxidants free phenolic acids can be released from the dietary fiber by the action of intestinal microflora composed among others also of Lactobacillus strains. The aim of this study was to examine four Lactobacillus strains (L. acidophilus K1, L. rhamnosus E/N, PEN, OXYfor the ability to produce extracellular FAE on different synthetic and natural carbon sources. Material and methods. The LAB strains were grown in the minimal growth media using German wheat bran, rye bran, brewers’ spent grain, isolated larchwood arabinogalactan, apple pectin, corn pectin, methyl ferulate, methyl p-coumarate, methyl syringate or methyl vanillate as the sole carbon source. FAE activity was determined using the post-cultivation supernatants, methyl ferulate and HPLC with UV detection. Results. The highest FAE activity was obtained with L. acidophilus K1 and methyl ferulate (max. 23.34 ±0.05 activity units and methyl p-coumarate (max. 14.96 ±0.47 activity units as carbon sources. L. rhamnosus E/N, OXY and PEN exhibited the limited ability to produce FAE with cinnamic acids methyl esters. Methyl syringate and methyl vanillate (MS and MV were insufficient carbon sources for FAE production. Brewers’ spent grain was the most suitable substrate for FAE production by L. acidophilus K1 (max. 2.64 ±0.06 activity units and L. rhamnosus E/N, OXY and PEN. FAE was also successfully induced by natural substrates rye bran, corn pectin (L. acidophilus K1, German wheat bran and larchwood arabinogalactan (E/N, PEN or German wheat bran and corn pectin (OXY. Conclusions. This study proved the

  12. Effect of synthetic mica on the thermal properties of poly(lactic acid

    Diego Holanda Saboya Souza

    2014-01-01

    Full Text Available Poly(lactic acid/Somasif fluoromica nanocomposites were prepared by melt blending and their thermal properties investigated by DSC, TGA and DMA. Three different types of synthetic mica (Somasif ME-100, Somasif MAE and Somasif MPE were used at different contents (2.5, 5.0 and 7.5 wt %. The melt blending of PLA and these micas is characterized by a considerable reduction in the matrix molecular weight, which decreases when the nanofiller content is increased. For all nanocomposites, the thermal stability increases when mica is added to the polymer, with the Somasif MPE, producing the highest increase of the degradation temperature and highest reduction of Tg.

  13. Anthranilic acid-containing cyclic tetrapeptides: at the crossroads of conformational rigidity and synthetic accessibility.

    Xin, Dongyue; Burgess, Kevin

    2016-06-14

    Each amino acid in a peptide contributes three atom units to main-chains, hence natural cyclic peptides can be 9, 12, 15, …. i.e. 3n membered-rings, where n is the number of amino acids. Cyclic peptides that are 9 or 12-membered ring compounds tend to be hard to prepare because of strain, while their one amino acid homologs (15-membered cyclic pentapeptides) are not conformationally homogeneous unless constrained by strategically placed proline or d-amino acid residues. We hypothesized that replacing one genetically encoded amino acid in a cyclic tetrapeptide with a rigid β-amino acid would render peptidomimetic designs that rest at a useful crossroads between synthetic accessibility and conformational rigidity. Thus this research explored non-proline containing 13-membered ring peptides 1 featuring one anthranilic acid (Anth) residue. Twelve cyclic peptides of this type were prepared, and in doing so the viability of both solution- and solid-phase methods was demonstrated. The library produced contained a complete set of four diastereoisomers of the sequence 1aaf (i.e. cyclo-AlaAlaPheAnth). Without exception, these four diastereoisomers each adopted one predominant conformation in solution; basically these conformations feature amide N-H vectors puckering above and below the equatorial plane, and approximately oriented their N-H[combining low line] atoms towards the polar axis. Moreover, the shapes of these conformers varied in a logical and predictable way (NOE, temperature coefficient, D/H exchange, circular dichroism). Comparisons were made of the side-chain orientations presented by compounds 1aaa in solution with ideal secondary structures and protein-protein interaction interfaces. Various 1aaa stereoisomers in solution present side-chains in similar orientations to regular and inverse γ-turns, and to the most common β-turns (types I and II). Consistent with this, compounds 1aaa have a tendency to mimic various turns and bends at protein

  14. Phase and extraction equilibria in water-polyethyleneglycol ethers of monoethanolamides of synthetic fatty acid-ammonium chloride systems

    Lesnov, A. E.; Golovkina, A. V.; Kudryashova, O. S.; Denisova, S. A.

    2016-08-01

    Phase equilibria in layering systems of water, polyethyleneglycol ethers of monoethanolamides of synthetic fatty acids (SFAs) (synthamide-5), and ammonium chloride are studied. The possibility of using such systems for the liquid extraction of metal ions is evaluated. The effect the nature of salting-out agents has on the processes of segregation of the systems has been considered.

  15. Stability of antibiotics and amino acids in two synthetic L-amino acid solutions commonly used for total parenteral nutrition in children

    Colding, H; Andersen, G E

    1978-01-01

    The stability and interaction at 29 degrees C of ampicillin, carbenicillin, gentamicin, and polymyxin B were examined in a common electrolyte solution, invertose darrow, and in two synthetic l-amino acid solutions, one commercial (vamin with fructose; Vitrum) and the other a neonatal preparation...

  16. Inhibitory effect of synthetic small interfering RNAs on glial fibrillary acidic expression in astrocytes

    Mingzhu Zhang; Qing Zhao; Xin Tang; Guangrong Yu

    2008-01-01

    BACKGROUND: Glial fibrillary acidic protein (GFAP) expression highly correlates with spinal glial scar formation, and is regarded as an important target for scar therapy. Efficient inhibition of expression could benefit recovery from spinal cord injury. OBJECTIVE: To investigate the inhibitory effects of synthetic small interfering RNAs (siRNAs) on astrocytie GFAP expression in rats. DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment at the cellular and molecular level was performed at the First Hospital of Dalian Medical University between June 2005 and February 2006. MATERIALS: A total of 100 seven-day-old, Sprague Dawley rats were selected. GAPDH siRNA was purchased from Ambion, USA, And TransMessengerTM Transfection Reagent from DAKO, Carpinteria, CA. METHODS: Rat astrocytes were isolated and cultured. Three pairs of 21-nucleotide (nt) siRNAs specific to rats GFAP mRNA, 401,404 and 854, were synthesized and transfected in primary astrocytes at 1, 2, 3, and 4 g/L using TransMessengerTM Transfection Reagent. Non-transfected astrocytes served as the blank group. Cells transfected with siRNA were regarded as the negative control group, with GAPDH siRNA as the positive control group, and 401 siRNA, 404 siRNA, and 854 siRNA as experimental groups. MAIN OUTCOME MEASURES: GFAP mRNA and protein expression were assessed by RT-PCR and Western blot, respectively, at 24, 48, and 72 hours of culture. RESULTS: GFAP mRNA expression in the positive control group was significantly less than the negative control group (P0.05). GFAP protein expression was remarkably less in siRNA-transfected astroeytes compared to the blank control (P < 0.01). CONCLUSION: Transfected siRNAs could significantly inhibit GFAP gene expression in astrocytes after 72 hours in culture.

  17. A Novel Synthetic Mycolic Acid Inhibits Bronchial Hyperresponsiveness and Allergic Inflammation in a Mouse Model of Asthma

    KIM, YOUNG-JOON; Kim, Ha-Jung; Jeong, Se Kyoo; Lee, Seung-Hwa; Kang, Mi-Jin; Yu, Ho-Sung; Jung, Young-Ho; Seo, Ju-Hee; Kim, Byoung-Ju; Yu, Jinho; Park, Seoung-Ju; Lee, Yong-Chul; Hong, Soo-Jong

    2013-01-01

    Purpose Recognition of microbes is important to trigger the innate immune system. Mycolic acid (MA) is a component of the cell walls of mycobacteria such as Mycobacterium bovis Bacillus Calmette-Guerin. MA has immunogenic properties, which may modulate the innate and adaptive immune response. This study aimed to investigate whether a novel synthetic MA (sMA) inhibits allergic inflammatory responses in a mouse model of asthma. Methods BALB/c mice were injected intraperitoneally with sMA follow...

  18. New synthetic bile acid analogue agonists of FXR and TGR5 receptors: Analytical methodologies for the study of their physico-chemical properties, pharmacokinetic activity and metabolism.

    Colliva, Carolina

    2013-01-01

    This thesis reports an integrated analytical approach for the study of physicochemical and biological properties of new synthetic bile acid (BA) analogues agonists of FXR and TGR5 receptors. Structure-activity data were compared with those previous obtained using the same experimental protocols on synthetic and natural occurring BA. The new synthetic BA analogues are classified in different groups according also to their potency as a FXR and TGR5 agonists: unconjugated and steroid modifie...

  19. Protective effects of Punica Granatum (L) and synthetic ellagic acid on radiation induced biochemical alterations in Swiss albino mice

    Ionizing radiations produce deleterious effects in the living organisms and the rapid technological advancement has increased human exposure to ionizing radiations enormously. Radiotherapy, which is a chief modality to treat cancer, faces a major drawback because it produces severe side effects developed due to damage to normal tissue by reactive oxygen species (ROS). Recent studies have indicated that some commonly used medicinal plants may be good sources of potent but non-toxic radioprotectors. The pomegranate, Punica granatum L., an ancient, mystical, and highly distinctive fruit, is the predominant member of the Punicaceae family. It is used in several systems of medicine for a variety of ailments. The objective of the present study was to investigate the protective effects of ethanolic extracts of pomegranate whole fruit (EPWF) and seeds (EPS) and Synthetic Ellagic acid (EA) against Electron beam radiation(EBR) induced biochemical alterations in Swiss albino mice. The extracts and synthetic compound were assessed for its radical scavenging property by DPPH radical scavenging and Ferric Reducing Antioxidant Power assays. The animals were exposed to sub-lethal dose (6 Gy) of Electron Beam Radiation and then treated with 200 mg/kg body wt. of pomegranate extracts and synthetic ellagic acid for 15 consecutive days. The biochemical estimations were carried out in the liver homogenate of the sacrificed animals. Radiation induced depletion in the level of reduced glutathione and total antioxidant capacity were prevented significantly by EPWF, EPS and EA administration. Also there was significant reduction in the levels of membrane lipid peroxidation in the treated groups compared to irradiated control. The findings of our study indicate the protective efficacy of pomegranate extracts and synthetic ellagic acid on radiation induced biochemical changes in mice may be due to its free radical scavenging and increased antioxidant levels. (author)

  20. Conversion of hydroxycinnamic acids into volatile phenols in a synthetic medium and in red wine by Dekkera bruxellensis

    Maria João Cabrita

    2012-03-01

    Full Text Available The conversion of p-coumaric acid, ferulic acid, and caffeic acid into 4-ethylphenol, 4-ethylguaiacol and 4-ethylcatechol was studied in Dekkera bruxellensis ISA 1791 under defined conditions in a synthetic medium and in a red wine. Liquid chromatography (HPLC-DAD was used to quantify the phenolic acids, and gas chromatography (GC coupled to a FID detector was used to quantify volatile phenols using a novel analytical methodology that does not require sample derivatization. Identification was achieved by gas chromatography-mass detection (GC-MS. The results show that phenolic acids concentration decreases while volatile phenols concentration increases. The proportion of caffeic acid taken up by Dekkera bruxellensis is lower than that for p-coumaric or ferulic acid; therefore less 4-ethylcatechol is formed. More important, 4-ethylcathecol synthesis by Dekkera bruxellensis in wine has never been demonstrated so far. These results contribute decisively to a better understanding of the origin of the volatile phenols in wines. The accumulation of these compounds in wine is nowadays regarded as one of the key factors of quality control.

  1. Aromaticity driven interfacial synthetic strategy for porous platinum nanostructure: An efficient electrocatalyst for methanol and formic acid oxidation

    Highlights: • A new surfactant free synthetic approach for porous platinum nanostructures. • The reduction process is aromaticity driven interfacial synthetic technique. • Two morphologically important Pt nanostructures were synthesized in two different reaction conditions. • Increasing the reaction temperature leads to the assembly of smaller size Pt nuclei to form porous platinum nanochanins (Pt NCs) with higher surface area. • Pt NCs exhibit better catalytic activity and also the stability for methanol and formic acid electrooxidation compared to platinum nanoflowers (synthesized under normal UV irradiation), Pt NPs and commercial Pt/C. - Abstract: Herein, template or surfactant free synthesis of porous platinum nanostructures has been reported from a liquid–liquid interfacial synthetic technique. Here the progress of the Pt4+ reduction has been governed by an aromaticity driven pathway of 2,4 dihydropyridine ester (DHPE) in dichloromethane (DCM). Thus morphologically two different Pt nanostructures at the liquid-liquid interface are evolved depending upon the imposed reaction conditions (UV irradiation or mild heat). Comparative methanol oxidation reaction (MOR) in basic condition illustrates that porous platinum nanochains (Pt NCs), synthesized under heat, show 14.63 and 1.43 times higher mass activity than platinum nanoparticles (Pt NPs) and platinum nanoflowers (Pt NFs), synthesized under UV irradiation. Furthermore Pt NCs exhibit remarkable catalytic stability for MOR and also superior catalytic efficiency for formic acid oxidation (FAOR) leaving aside CO poisoning. The assembly of Pt nanowires generates porous Pt NCs which provide the oppertunity for better utilization of expensive Pt in electrocatalysis in terms of its higher mass activity and stability compared to even commercial Pt/C catalyst. Thus our proposed synthetic procedure for naked and porous platinum nanostructure foretells its practical fuel cell application

  2. A comparison of f-element dissociation kinetics from synthetic polyelectrolytes and humic acid

    Due to their large complexing capacities, natural humic substances have been proposed as scavengers of toxic metals in aquatic systems. We studied f-element dissociation rates from naturally occurring and well characterized synthetic polyelectrolytes as a function of ph, aging time of the metal complex, and polyacid molecular weight

  3. Production of extracellular ferulic acid esterases by Lactobacillus strains using natural and synthetic carbon sources

    Dominik Szwajgier; Anna Jakubczyk

    2011-01-01

    Background. Ferulic acid esterases (FAE, EC 3.1.1.73), also known as feruloyl esterases, cinnamic acid esterases or cinnamoyl esterases, belong to a common group of hydrolases distributed in the plant kingdom. Especially the fungal enzymes were very well characterised in the past whereas the enzyme was rarely found in the lactic acid bacteria (LAB) strains. It is well known that strong antioxidants free phenolic acids can be released from the dietary fiber by the action of intestinal microflo...

  4. Novel ferulic acid esterases from Bifidobacterium sp. produced on selected synthetic and natural carbon sources

    Dominik Szwajgier; Anna Dmowska

    2010-01-01

    Background. Ferulic acid esterases (or feruloyl esterases), a common group of hydrolases are very well distributed in the plant kongdom. The fungal feruloyl esterases were very extensively studied whereas probiotic lactic acid bacteria as the source of this enzyme were generally omitted. Free phenolic acids – strong antioxidants can be released from the dietary fiber by the action of intestinal lactic acid bacteria. The aim of this study was to examine the three probiotic Bifi...

  5. Batch fermentations on synthetic mixed sugar and starch medium with amylolytic lactic acid bacteria

    Thomsen, Mette Hedegaard; Guyot, J.P.; Kiel, P.

    2007-01-01

    process. A number of amylolytic lactic acid bacteria have been identified, and in this work, six different strains were tested for their ability to produce alpha-amylase and to utilise all sugars with high lactic acid yield in a medium with a complex composition of free sugars (brown juice) and starch...... brown juice. Brown juice was shown to be an excellent medium for lactic acid fermentation. The aim of this study was to investigate the utilisation of brown juice in the production of polylactic acid, where wheat starch would be added to increase the lactic acid yield and, thus, the feasibility of the....... Lactobacillus plantarum A6 was the only strain that showed both a good lactic acid production and utilisation of starch in this medium. The growth rate of this strain was approximately 0.4 h(-1) and the lactic acid yield was 0.7....

  6. γ Actinorhodin a natural and attorney source for synthetic dye to detect acid production of fungi

    Manikprabhu, Deene; K. Lingappa

    2013-01-01

    Colors from natural sources are gaining popularity because synthetic colors are carcinogenic. Natural colors are obtained from plants or microorganisms. Pigments produced by microorganisms have advantages over plant pigments, due to their ease of use and reliability. In the present study, a blue pigment producing actinomycete klmp33 was isolated from the Gulbarga region in India. The isolate was identified based on morphologic, microscopic, and biochemical characterization, and 16S rRNA seque...

  7. Kinetics for the synthetic bile acid 75-selenohomocholic acid-taurine in humans: comparison with [14C]taurocholate

    The apparent fractional turnover rate of the gamma-labeled bile acid analogue 75-selenohomocholic acid-taurine (75-SeHCAT) was assessed from decline in radioactivity over the gallbladder area on 4 successive days using a gamma-camera, and was compared in the same subjects with the fractional turnover rate of the corresponding natural bile acid, cholic acid-taurine, labeled with 14C ([14C]CAT) using the classical Lindstedt technique. Very similar results were obtained in 5 healthy individuals (coefficient of variation 4.8%, medians 0.35 and 0.34, respectively). By contrast, the fractional deconjugation rate assessed from zonal scanning of glycine- and taurine-conjugated bile acids on thin-layer chromatography was much less for 75-SeHCAT than for [14C]CAT (0.02 and 0.13, respectively; p less than 0.05). The fractional rate for deconjugation plus dehydroxylation was also determined by zonal scanning, and gave lower values for 75-SeHCAT than for [14C]CAT (0.02 and 0.12, respectively; p less than 0.05). There was a striking similarity between the fractional rate for deconjugation alone and that for deconjugation plus dehydroxylation for both bile acids in individual samples (r = 0.999, p less than 0.001), suggesting that these two processes might occur simultaneously and probably involve the same bacteria. We conclude that our scintiscanning technique provides an accurate, noninvasive method of measuring fractional turnover rate of a bile acid in humans, and that the finding that 75SeHCAT remains conjugated with taurine during enterohepatic recycling means that absorption should be specific for the ileal active transport site, thus rendering it an ideal substance for assessing ileal function

  8. A synthetic approach to carbon-14 labeled anti-bacterial naphthyridine and quinolone carboxylic acids

    Ekhato, I.V.; Huang, C.C. (Parke, Davis and Co., Ann Arbor, MI (United States))

    1993-09-01

    Labeled versions of (S)-clinafloxacin (1) and two napththyridine carboxylic acid anti-bacterial compounds 2 and 3 which are currently in development were synthesized. Preparations started from hitherto unknown bromo compounds 22 and 10, from which the corresponding [sup 14]C-labeled aromatic carboxylic acids 23 and 12 were generated by metal-halogen exchange followed by carboxylation reaction. Details of these preparations are given. (author).

  9. To assess of behavior of natural colloid (soil extraction and fractionation of natural water) humus acid in comparison with synthetic humus acid

    Dinu, Marina; Shkinev, Valery

    2015-04-01

    To study and predict the fate of natural colloid - nanoparticles in surface water or soil extraction - necessary to understand the features of the migration and physic-chemical activity of biocolloids. Comparison of the behavior of natural biocolloids, such as humus acid extracts of soil or natural water with artificial, synthetic humic acids (introduced into the environment) allows you to explore the mechanism of formation and transformation biocolloids under the influence of a number of parameters. In this work, we studied these interactions in natural surface waters from lakes and soil (Russian Federation, Kola North and Western Siberia) which displaying contrast organic and inorganic compositions. During the study, researches identified zonal features influence on the qualitative and quantitative composition of colloids, their stability and chemical activity. A model approach was also followed with synthetic water of comparable composition in order to better understand the driving mechanisms. We investigated the size, zeta potential and other physical and chemical parameters of the system. Particular attention is given to the process of complexation with heavy metal ions. As humic substances have excellent complexion properties and reduce the toxicity of many metal ions. The study of such non-static natural systems allow studying the features of the existence of natural colloidal components. The use of synthetic humic substances, which were introduced into the natural environment possible to study the standard mechanisms of formation, development and destruction of colloidal polymer systems. The obtained results allowed with used computer programs MatnLab, MathCad, Statistics simulate the processes of formation, development and functioning of natural colloids.

  10. Hepatic handling of a synthetic gamma-labeled bile acid (75SeHCAT)

    75Se-homocholic acid-taurine (75SeHCAT) is the first available gamma-labeled bile acid, and should therefore be handled more efficiently and specifically by the liver than previous hepatoscintigraphic agents. We have measured serum and hepatic kinetics for 75SeHCAT, and compared them with those for the conventional hepatobiliary scintigraphic agent 99mTc-hepatoiminodiacetic acid, and with serum kinetics for the corresponding natural bile acid, [14C]cholic acid-taurine. We used a dynamic scintigraphic technique and serial blood sampling in 8 subjects. Initial hepatic uptake rate was identical to initial serum disappearance rate (14% dose/min) for 75SeHCAT, but significantly lower for 99mTc-hepatoiminodiacetic acid (6% vs. 14% dose/min, p less than 0.001). Hepatic transit time was shorter for 75SeHCAT (13 min vs. 22 min, p less than 0.02), net hepatic excretory rate was more rapid (1.4% vs. 0.8% dose/min, p less than 0.001), and urinary excretion was lower (1.0% vs. 9.0% dose, p less than 0.001). Initial and late-plasma disappearance rates were significantly lower for 75SeHCAT (14.3% and 1.5% dose/min) than for [14C]cholic acid-taurine (21.3% and 2.8% dose/min, respectively), and plasma clearance was also lower (275 vs. 670 ml/min). In vitro, 75SeHCAT was bound to serum proteins more completely than [14C]cholic acid-taurine (90.4% vs. 86.5%, p less than 0.005). We conclude that 75SeHCAT provides a hepatoscintigraphic agent that is handled more efficiently and specifically by the liver than the conventionally used agent 99mTc-hepatoiminodiacetic acid. It is not cleared from the serum as rapidly as [14C]cholic acid-taurine, probably due to its stronger protein binding. The clinical value of 75SeHCAT in assessing liver disease should be investigated

  11. Development of a Synthetic Process for N-Cyclohexylmaleiamic Acid Isobutyl Ester

    Moon, Bu-Hyun; Ju, Chang-Sik [Pukyoung National University, Busan (Korea, Republic of)

    2013-10-15

    For the purpose of development of effective synthetic process of CHMI, a series of experiments were preformed on the preparation of CHMAIE, the intermediate of CHMI. For the first step, CHMA was synthesized by dropwise mixing of cyclohexylamine with maleic anhydride in toluene and 98.2% of theoretical CHMA was obtained by precipitation at 10 .deg. C for 2 hours. The optimum reaction temperature of the esterification, preparation reaction of CHAMIE from CHMA, was 68 .deg. C, and equilibrium conversion at optimum temperature was 98.5%. Equilibrium reaction time decreased with reaction temperature, and 4 hours was taken to reach equilibrium at optimum reaction temperature. Toluene in the final reaction product could be recovered by vacuum distillation. The recovery of toluene was increased with distillation temperature and 98% of toluene could be recovered at 55 .deg. C.

  12. Synthetic Astrobiology

    Rothschild, Lynn J.

    2015-01-01

    Synthetic biology - the design and construction of new biological parts and systems and the redesign of existing ones for useful purposes - has the potential to transform fields from pharmaceuticals to fuels. Our lab has focused on the potential of synthetic biology to revolutionize all three major parts of astrobiology: Where do we come from? Where are we going? and Are we alone? For the first and third, synthetic biology is allowing us to answer whether the evolutionary narrative that has played out on planet earth is likely to have been unique or universal. For example, in our lab we are re-evolving the biosynthetic pathways of amino acids in order to understand potential capabilities of an early organism with a limited repertoire of amino acids and developing techniques for the recovery of metals from spent electronics on other planetary bodies. In the future synthetic biology will play an increasing role in human activities both on earth, in fields as diverse as human health and the industrial production of novel bio-composites. Beyond earth, we will rely increasingly on biologically-provided life support, as we have throughout our evolutionary history. In order to do this, the field will build on two of the great contributions of astrobiology: studies of the origin of life and life in extreme environments.

  13. Synthetic Astrobiology

    Rothschild, Lynn J.

    2016-01-01

    Synthetic biology - the design and construction of new biological parts and systems and the redesign of existing ones for useful purposes - has the potential to transform fields from pharmaceuticals to fuels. Our lab has focused on the potential of synthetic biology to revolutionize all three major parts of astrobiology: Where do we come from? Where are we going? and Are we alone? For the first and third, synthetic biology is allowing us to answer whether the evolutionary narrative that has played out on planet earth is likely to have been unique or universal. For example, in our lab we are re-evolving the biosynthetic pathways of amino acids in order to understand potential capabilities of an early organism with a limited repertoire of amino acids and developing techniques for the recovery of metals from spent electronics on other planetary bodies. And what about the limits for life? Can we create organisms that expand the envelope for life? In the future synthetic biology will play an increasing role in human activities both on earth, in fields as diverse as human health and the industrial production of novel bio-composites. Beyond earth, we will rely increasingly on biologically-provided life support, as we have throughout our evolutionary history. In order to do this, the field will build on two of the great contributions of astrobiology: studies of the origin of life and life in extreme environments.

  14. Labelled Thioamino Acids to Indicate the Synthetic Activity of the Rumen Bacteria in In-Vitro Experiments

    The synthetic activity of rumen bacteria has been studied in vitro through the investigation of cystine and methionine concentration and their specific activity. 35S-sulphate has been used as a radioactive tracer. Two diets, different in the level of nutrients - energy and protein - were added to the artificial tumen. The incubation with bacteria from the rumen content of the cows, fed for four weeks with the same diet, lasted 19 h. The diet with the higher level of protein and energy increased the cystine content (per 100 mg of N2) by 23.3% and the methionine content by 39.4%. The concentration of radioactive cystine was increased at the same percentage rate by 25%, but radioactive methionine was much lower and increased only 6.4%. The difference between the specific activities of the investigated amino acids can be explained by the different catabolism rate and utilization of dietary cystine, and methionine by the rumen bacterial flora. Since the dietary methionine is catabolized slowly, it can, especially by the use of the diets with a high protein level, significantly decrease the specific activity of the radioactive methionine synthesized by rumen bacteria. Therefore, the incorporation of 35S into the cystine represents a more reliable indicator of the synthetic activity of the rumen bacteria. (author)

  15. Convenient synthetic method of starch/lactic acid graft copolymer catalyzed with sodium hydroxide

    Qingling Wang; Yingmo Hu; Jianhua Zhu; Yang Liu; Xue Yang; Jing Bian

    2012-06-01

    Copolymer of starch grafted with lactic acid (LA) could be directly prepared by reaction of cornstarch with lactic acid and with sodium hydroxide (NaOH) as the catalyst. The structure of starch/LA copolymer was characterized by IR, XRD, SEM and 1H-NMR. The effects of NaOH concentration, ratios of starch and LA, reaction temperature and reaction time on the grafting degree were also investigated and the results showed that the highest grafting degree of starch could reach 33.60% when the graft copolymerization was carried out in 0.40 mol l-1 NaOH aqueous solution for 9 h at 90°C with 1: 6 ratio of starch and lactic acid.

  16. DNA and RNA "traffic lights": synthetic wavelength-shifting fluorescent probes based on nucleic acid base substitutes for molecular imaging.

    Holzhauser, Carolin; Wagenknecht, Hans-Achim

    2013-08-01

    The DNA base substitute approach by the (S)-3-amino-1,2-propanediol linker allows placing two fluorophores in a precise way inside a given DNA framework. The double helical architecture around the fluorophores, especially the DNA-induced twist, is crucial for the desired photophysical interactions. Excitonic, excimer, and energy transfer interactions yield fluorescent DNA and RNA probes with dual emission color readout. Especially, our DNA and RNA "traffic light" that combines the green emission of TO with the red emission of TR represents an important tool for molecular imaging and can be applied as aptasensors and as probes to monitor the siRNA delivery into cells. The concept can be extended to the synthetically easier to access postsynthetic 2'-modifications and the NIR range. Thereby, the pool of tailor-made fluorescent nucleic acid conjugates can be extended. PMID:23796243

  17. Synthetic poly(amino acid)-based biomaterials for tissue regeneration

    Rypáček, František; Studenovská, Hana; Proks, Vladimír; Machová, Luďka; Vodička, Petr; Hlučilová, Jana; Motlík, Jan

    Toronto: Department of Aerospace & Mechanical Engineering, Ryerson University, 2006. s. 155. [International Conference on Processing & Manufacturing of Advanced Materials. 04.07.2006-08.07.2006, Vancouver] R&D Projects: GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505 Keywords : biomaterials * poly(amino acids) * tissue regeneration Subject RIV: CD - Macromolecular Chemistry

  18. Magnetic microparticles post-synthetically coated by hyaluronic acid as an enhanced carrier for microfluidic bioanalysis

    Holubová, L.; Knotek, P.; Palarčik, J.; Čadková, M.; Bělina, P.; Vlček, Milan; Korecká, L.; Bílková, Z.

    2014-01-01

    Roč. 44, 1 November (2014), s. 345-351. ISSN 0928-4931 R&D Projects: GA ČR GAP206/12/0381 Institutional support: RVO:61389013 Keywords : coating * hyaluronic acid * hyaluronan Subject RIV: CA - Inorganic Chemistry Impact factor: 3.088, year: 2014

  19. Production of fatty acid-derived oleochemicals and biofuels by synthetic yeast cell factories

    Zhou, Yongjin J.; Buijs, Nicolaas A; Zhu, Zhiwei;

    2016-01-01

    alcohol dehydrogenases and aldehyde reductases, we reconstruct efficient pathways for conversion of fatty acids to alkanes (0.8 mg l−1) and fatty alcohols (1.5 g l−1), to our knowledge the highest titres reported in S. cerevisiae. This should facilitate the construction of yeast cell factories for...

  20. Synthetic poly(amino acid) hydrogels with incorporated cell-adhesion peptides for tissue engineering

    Studenovská, Hana; Vodička, Petr; Proks, Vladimír; Hlučilová, Jana; Motlík, Jan; Rypáček, František

    2010-01-01

    Roč. 4, č. 6 (2010), s. 454-463. ISSN 1932-6254 R&D Projects: GA AV ČR KJB400500801; GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50450515 Keywords : polyamino acid * hydrogel * porosity Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.534, year: 2010

  1. Production of fatty acid-derived oleochemicals and biofuels by synthetic yeast cell factories.

    Zhou, Yongjin J; Buijs, Nicolaas A; Zhu, Zhiwei; Qin, Jiufu; Siewers, Verena; Nielsen, Jens

    2016-01-01

    Sustainable production of oleochemicals requires establishment of cell factory platform strains. The yeast Saccharomyces cerevisiae is an attractive cell factory as new strains can be rapidly implemented into existing infrastructures such as bioethanol production plants. Here we show high-level production of free fatty acids (FFAs) in a yeast cell factory, and the production of alkanes and fatty alcohols from its descendants. The engineered strain produces up to 10.4 g l(-1) of FFAs, which is the highest reported titre to date. Furthermore, through screening of specific pathway enzymes, endogenous alcohol dehydrogenases and aldehyde reductases, we reconstruct efficient pathways for conversion of fatty acids to alkanes (0.8 mg l(-1)) and fatty alcohols (1.5 g l(-1)), to our knowledge the highest titres reported in S. cerevisiae. This should facilitate the construction of yeast cell factories for production of fatty acids derived products and even aldehyde-derived chemicals of high value. PMID:27222209

  2. Encapsulating Metal Clusters and Acid Sites within Small Voids: Synthetic Strategies and Catalytic Consequences

    Goel, Sarika

    The selective encapsulation of metal clusters within zeolites can be used to prepare clusters that are uniform in diameter and to protect them against sintering and contact with feed impurities, while concurrently allowing active sites to select reactants based on their molecular size, thus conferring enzyme-like specificity to chemical catalysis. The apertures in small and medium-pore zeolites preclude the use of post-synthetic protocols to encapsulate the relevant metal precursors because cationic or anionic precursors with their charge-balancing double layer and gaseous complexes cannot diffuse through their windows or channels. We have developed general strategies to encapsulate metal clusters within small-pore zeolites by using metal precursors stabilized by ammonia or organic amine ligands, which stabilize metal precursors against their premature precipitation at the high temperature and pH conditions required for the hydrothermal synthesis of the target zeolite structures and favor interactions between metal precursors and incipient aluminosilicate nuclei during the self-assembly of microporous frameworks. When synthesis temperatures were higher than 400 K, available ligands were unable to prevent the premature precipitation of the metal precursors. In such cases, encapsulation was achieved instead via interzeolite transformations after successfully encapsulating metal precursors or clusters via post-synthesis exchange or ligand protection into parent zeolites and subsequently converting them into the target structures while retaining the encapsulated clusters or precursors. Such strategies led to the successful selective encapsulation of a wide range of metal clusters (Pt, Pd, Ru, Rh, Ir, Re, and Ag) within small-pore (SOD (sodalite), LTA (Linde type A (zeolite A)), GIS (gismondine), and ANA (analcime)) and medium-pore (MFI (ZSM-5)) zeolites. These protocols provide novel and diverse mechanism-based strategies for the design of catalysts with protected

  3. Application of advanced oxidation processes for removing salicylic acid from synthetic wastewaters

    Djalma; Ribeiro; da; Silva; Carlos; A.Martinez-Huítle

    2010-01-01

    In this study,advanced oxidation processes(AOPs) such as anodic oxidation(AO),UV/H_2O_2 and Fenton processes(FP) were investigated for the degradation of salicylic acid(SA) in lab-scale experiments.Boron-doped diamond(BDD) film electrodes using Ta as substrates were employed for AO of SA.In the case of FP and UV/H_2O_2,most favorable experimental conditions were determined for each process and these were used for comparing with AO process.The study showed that the FP was the most effective process under ...

  4. Covalent binding of sulfamethazine to natural and synthetic humic acids: assessing laccase catalysis and covalent bond stability.

    Gulkowska, Anna; Sander, Michael; Hollender, Juliane; Krauss, Martin

    2013-07-01

    Sulfonamide antibiotics form stable covalent bonds with quinone moieties in organic matter via nucleophilic addition reactions. In this work, we combined analytical electrochemistry with trace analytics to assess the catalytic role of the oxidoreductase laccase in the binding of sulfamethazine (SMZ) to Leonardite humic acid (LHA) and to four synthetic humic acids (SHAs) polymerized from low molecular weight precursors and to determine the stability of the formed bonds. In the absence of laccase, a significant portion of the added SMZ formed covalent bonds with LHA, but only a very small fraction (<0.4%) of the total quinone moieties in LHA reacted. Increasing absolute, but decreasing relative concentrations of SMZ-LHA covalent bonds with increasing initial SMZ concentration suggested that the quinone moieties in LHA covered a wide distribution in reactivity for the nucleophilic addition of SMZ. Laccase catalyzed the formation of covalent bonds by oxidizing unreactive hydroquinone moieties in LHA to reactive, electrophilic quinone moieties, of which a large fraction (5%) reacted with SMZ. Compared to LHA, the SHA showed enhanced covalent bond formation in the absence of laccase, suggesting a higher reactivity of their quinone moieties toward nucleophilic addition. This work supports that binding to soil organic matter (SOM) is an important process governing the fate, bioactivity, and extractability of sulfonamides in soils. PMID:23384282

  5. Structural transformations of the synthetic salt 4`, 7-dihydroxyflavylium chloride in acid and basic aqueous solutions. Part 1-Ground state

    Pina, F.; Benedito, L.; Melo, M.J.; Parola, A.J. [Centro de Quimica Fina e Biotecnologia. Departamento de Quimica FCT/UNL, Portugal (Portugal); Lima, J.C.; Macanita, A.L. [Instituto de Tecnologia Quimica e Biologica, Portugal (Portugal)

    1997-09-01

    A complete study of the structural pH dependent transformations of the synthetic flavylium salt 4`-7-dihydroxyflavylium chloride (DHF), occurring in aqueous solutions, including the basic region, is described. The kinetics study of the transformations occurring in acidic media (quinoidal base (A) {l_reversible} flavylium cation (AH{sup +}) {l_reversible} hemiacetal (B) {l_reversible} cis-chalcone (C-cis) {l_reversible} trans-chalcone (C-trans)) allowed to conclude that the cis-transisomerization is faster than the tautomerization and the hydration processes, which is unique in the anthocyanins family. Results obtained with the parent compound 4`-7-dimethoxyflavylium chloride (DMF)with relevance to this study are also presented. In equilibrated basic solutions the existence of acid-base equilibria involving the trans-Chalcone (C-trans) and its conjugated bases, (C-trans, and C``2-trans), was detected. Freshly prepared solutions at pH>7 show also the presence of a transient species identified as the ionized quinoidal base (A``-), which is almost completely converted into C``2-trans with a Ph dependent rate constant, (Author) 17 refs.

  6. Removal of heavy metals from acid mine drainage (AMD) using coal fly ash, natural clinker and synthetic zeolites.

    Ríos, C A; Williams, C D; Roberts, C L

    2008-08-15

    Acid mine drainage (AMD) is a widespread environmental problem associated with both working and abandoned mining operations, resulting from the microbial oxidation of pyrite in presence of water and air, affording an acidic solution that contains toxic metal ions. The generation of AMD and release of dissolved heavy metals is an important concern facing the mining industry. The present study aimed at evaluating the use of low-cost sorbents like coal fly ash, natural clinker and synthetic zeolites to clean-up AMD generated at the Parys Mountain copper-lead-zinc deposit, Anglesey (North Wales), and to remove heavy metals and ammonium from AMD. pH played a very important role in the sorption/removal of the contaminants and a higher adsorbent ratio in the treatment of AMD promoted the increase of the pH, particularly using natural clinker-based faujasite (7.70-9.43) and the reduction of metal concentration. Na-phillipsite showed a lower efficiency as compared to that of faujasite. Selectivity of faujasite for metal removal was, in decreasing order, Fe>As>Pb>Zn>Cu>Ni>Cr. Based on these results, the use of these materials has the potential to provide improved methods for the treatment of AMD. PMID:18221835

  7. Simultaneous/Selective Detection of Dopamine and Ascorbic Acid at Synthetic Zeolite-Modified/Graphite-Epoxy Composite Macro/Quasi-Microelectrodes

    Rodica Pode; Elida Cristina Ilinoiu; Pier Andrea Serra; Florica Manea

    2013-01-01

    The present paper aims to miniaturize a graphite-epoxy and synthetic zeolite-modified graphite-epoxy composite macroelectrode as a quasi-microelectrode aiming in vitro and also, envisaging in vivo simultaneous electrochemical detection of dopamine (DA) and ascorbic acid (AA) neurotransmitters, or DA detection in the presence of AA. The electrochemical behavior and the response of the designed materials to the presence of dopamine and ascorbic acid without any protective membranes were studied...

  8. Batch coparative study of sorptive study of sorptive properties of two varieties of almond peels for bezanyl red (acid dye) from synthetic aqueous solutions

    BENAISSA, H.; Boumediene, M

    2012-01-01

    The ability of two varieties (hard and soft) of almond peels, as inexpensive sorbents for the removal of bezanyl red (acid dye) from synthetic aqueous solutions has been studied. After their characterization by different techniques, (elemental analysis, biochemical analysis, IR spectroscopy, thermogravimetric analysis, scanning electron microscopy and mercury porosimetry), the dye sorption kinetics and equilibrium isotherm have been investigated in batch conditions. The in...

  9. Immunogenicity of a synthetic HBsAg peptide: enhancement by conjugation to a fatty acid carrier.

    Hopp, T P

    1984-01-01

    Effective immunization with short polypeptide antigens has typically only been possible when the peptide is conjugated to a large carrier substance, usually a protein. Such immunizations suffer from difficulties in producing conjugates of reliable composition, and from unwanted anti-carrier immune responses. When a chemically synthesized peptide, bearing hepatitis B virus a-determinant specificity, was conjugated to a dipalmityl-lysine moiety, a significant improvement in anti-hepatitis B surface antigen response was obtained, in comparison to the corresponding peptide-keyhole limpet hemocyanin conjugate. Dipalmityl lysyl peptide conjugates are readily made by standard Merrifield synthesis procedures, and are relatively free of byproducts that might cause unwanted immune responses. Gel filtration experiments suggest that the conjugates form large aggregates, possibly micelles, which may play a significant role in the enhancement of the anti-peptide response. These properties suggest that fatty acid conjugation may be a useful procedure for producing chemically synthesized peptide vaccines. PMID:6423970

  10. Synthetic analogues of the natural compound cryphonectric acid interfere with photosynthetic machinery through two different mechanisms.

    Teixeira, Róbson Ricardo; Pereira, Wagner Luiz; Tomaz, Deborah Campos; de Oliveira, Fabrício Marques; Giberti, Samuele; Forlani, Giuseppe

    2013-06-12

    A series of isobenzofuran-1(3H)-ones (phthalides), analogues of the naturally occurring phytotoxin cryphonectric acid, were designed, synthesized, and fully characterized by NMR, IR, and MS analyses. Their synthesis was achieved via condensation, aromatization, and acetylation reactions. The measurement of the electron transport chain in spinach chloroplasts showed that several derivatives are capable of interfering with the photosynthetic apparatus. Few of them were found to inhibit the basal rate, but a significant inhibition was brought about only at concentrations exceeding 50 μM. Some other analogues acted as uncouplers or energy transfer inhibitors, with a remarkably higher effectiveness. Isobenzofuranone addition to the culture medium inhibited the growth of the cyanobacterium Synechococcus elongatus , with patterns consistent with the effects measured in vitro upon isolated chloroplasts. The most active derivatives, being able to completely suppress algal growth at 20 μM, may represent structures to be exploited for the design of new active ingredients for weed control. PMID:23678958

  11. IRMPD spectroscopy of protonated S-nitrosocaptopril, a biologically active, synthetic amino acid.

    Coletti, Cecilia; Re, Nazzareno; Scuderi, Debora; Maître, Philippe; Chiavarino, Barbara; Fornarini, Simonetta; Lanucara, Francesco; Sinha, Rajeev K; Crestoni, Maria Elisa

    2010-11-01

    S-Nitrosocaptopril, a biologically active S-nitrosothiol, is generated as protonated species and isolated in the gas phase by electrospray ionization coupled to Fourier Transform Ion Cyclotron Resonance (FT-ICR) or ion-trap mass spectrometry. The structural and IR spectroscopic characterization of protonated S-nitrosocaptopril (SNOcapH(+)) is aided by the comparative study of the parent species lacking the NO feature, namely protonated captopril. The study is accomplished by methodologies based on tandem mass spectrometry, namely by energy resolved collision-induced dissociation and infrared multiple-photon dissociation (IRMPD) spectroscopy, backed by density functional theory calculations. IRMPD spectra have been obtained both in the 1000-1900 cm(-1) fingerprint range, using a beamline of the infrared free electron laser (IR-FEL) at the Centre Laser Infrarouge d'Orsay (CLIO), and in the O-H and N-H stretching region (2900-3700 cm(-1)) using the tunable IR radiation of a tabletop parametric oscillator/amplifier (OPO/OPA) laser source. The structural features of the ion have been ascertained by comparison of the experimental IRMPD spectra with the IR transitions calculated for the lowest energy isomers. Evidence is obtained that protonation occurs at the amide carbonyl oxygen which is found to be the thermodynamically most basic site. However, SNOcapH(+) is present as a thermally equilibrated mixture of low-energy structures, with a major contribution of the most stable isomer characterized by a trans relationship of the positively charged OH group with respect to the carboxylic acid functionality on the adjacent proline ring and by an anti conformation at the S-N (partial) double bond, though the energy difference with the analogous trans-syn isomer is less than 1 kJ mol(-1). The highly diagnostic N-O stretching mode has been unambiguously identified, which may be regarded as an informative probe for S-nitrosation features in more complex, biologically active

  12. Simultaneous/Selective Detection of Dopamine and Ascorbic Acid at Synthetic Zeolite-Modified/Graphite-Epoxy Composite Macro/Quasi-Microelectrodes

    Rodica Pode

    2013-06-01

    Full Text Available The present paper aims to miniaturize a graphite-epoxy and synthetic zeolite-modified graphite-epoxy composite macroelectrode as a quasi-microelectrode aiming in vitro and also, envisaging in vivo simultaneous electrochemical detection of dopamine (DA and ascorbic acid (AA neurotransmitters, or DA detection in the presence of AA. The electrochemical behavior and the response of the designed materials to the presence of dopamine and ascorbic acid without any protective membranes were studied by cyclic voltammetry and constant-potential amperometry techniques. The catalytic effect towards dopamine detection was proved for the synthetic zeolite-modified graphite-epoxy composite quasi-microelectrode, allowing increasing the sensitivity and selectivity for this analyte detection, besides a possible electrostatic attraction between dopamine cation and the negative surface of the synthetic zeolite and electrostatic repulsion with ascorbic acid anion. Also, the synthetic zeolite-modified graphite-epoxy composite quasi-microelectrode gave the best electroanalytical parameters for dopamine detection using constant-potential amperometry, the most useful technique for practical applications.

  13. Synthetic Approaches to L-Iduronic Acid and L-Idose: Key Building Blocks for the Preparation of Glycosaminoglycan Oligosaccharides.

    Mohamed, Shifaza; Ferro, Vito

    2015-01-01

    L-Iduronic acid (IdoA) is an important monosaccharide component of glycosaminoglycans (GAGs) such as heparin, heparan sulfate and dermatan sulfate. GAGs are complex, highly sulfated polysaccharides that mediate a multitude of physiological and pathological processes via their interactions with a range of diverse proteins. The main challenge in the synthesis of GAG oligosaccharides is the efficient gram-scale preparation of IdoA building blocks since neither IdoA nor L-idose is commercially available or readily accessible from natural sources. In this review, the different synthetic approaches for the preparation of IdoA and its derivatives, including L-idose, are presented and discussed. Derivatives of the latter are often used in GAG synthesis and are elaborated to IdoA via selective oxidation at C-6 after incorporation into a GAG chain. Particular focus will be given to the preparation of IdoA synthons most commonly used for GAG oligosaccharide synthesis, and on the progress made since the last systematic review in this area. PMID:26613814

  14. Inhibition of mild steel corrosion in acidic medium using synthetic and naturally occurring polymers and synergistic halide additives

    Umoren, S.A. [Department of Chemistry, Faculty of Science, University of Uyo, P.M.B 1017 Uyo (Nigeria)], E-mail: saviourumoren@yahoo.com; Ogbobe, O.; Igwe, I.O. [Department of Polymer and Textile Engineering, School of Engineering and Engineering Technology, Federal University of Technology, P.M.B. 1526 Owerri (Nigeria); Ebenso, E.E. [Department of Chemistry and Chemical Technology, National University of Lesotho, P. O. Roma180, Lesotho (South Africa)

    2008-07-15

    The corrosion inhibition of mild steel in H{sub 2}SO{sub 4} in the presence of gum arabic (GA) (naturally occurring polymer) and polyethylene glycol (PEG) (synthetic polymer) was studied using weight loss, hydrogen evolution and thermometric methods at 30-60 deg. C. PEG was found to be a better inhibitor for mild steel corrosion in acidic medium than GA. The effect of addition of halides (KCl, KBr and KI) was also studied. Results obtained showed that inhibition efficiency (I%) increased with increase in GA and PEG concentration, addition of halides and with increase in temperature. Increase in inhibition efficiency (I%) and degree of surface coverage ({theta}) was found to follow the trend Cl{sup -} < Br{sup -} < I{sup -} which indicates that the radii and electronegativity of the halide ions play a significant role in the adsorption process. GA and PEG alone and in combination with halides were found to obey Temkin adsorption isotherm. Phenomenon of chemical adsorption is proposed from the trend of inhibition efficiency with temperature and values {delta}G{sub ads}{sup 0} obtained. The synergism parameter, S{sub I} evaluated is found to be greater than unity indicating that the enhanced inhibition efficiency caused by the addition of halides is only due to synergism.

  15. Function and evolution of the serotonin-synthetic bas-1 gene and other aromatic amino acid decarboxylase genes in Caenorhabditis

    Hare Emily E

    2004-08-01

    Full Text Available Abstract Background Aromatic L-amino acid decarboxylase (AADC enzymes catalyze the synthesis of biogenic amines, including the neurotransmitters serotonin and dopamine, throughout the animal kingdom. These neurotransmitters typically perform important functions in both the nervous system and other tissues, as illustrated by the debilitating conditions that arise from their deficiency. Studying the regulation and evolution of AADC genes is therefore desirable to further our understanding of how nervous systems function and evolve. Results In the nematode C. elegans, the bas-1 gene is required for both serotonin and dopamine synthesis, and maps genetically near two AADC-homologous sequences. We show by transformation rescue and sequencing of mutant alleles that bas-1 encodes an AADC enzyme. Expression of a reporter construct in transgenics suggests that the bas-1 gene is expressed, as expected, in identified serotonergic and dopaminergic neurons. The bas-1 gene is one of six AADC-like sequences in the C. elegans genome, including a duplicate that is immediately downstream of the bas-1 gene. Some of the six AADC genes are quite similar to known serotonin- and dopamine-synthetic AADC's from other organisms whereas others are divergent, suggesting previously unidentified functions. In comparing the AADC genes of C. elegans with those of the congeneric C. briggsae, we find only four orthologous AADC genes in C. briggsae. Two C. elegans AADC genes – those most similar to bas-1 – are missing from C. briggsae. Phylogenetic analysis indicates that one or both of these bas-1-like genes were present in the common ancestor of C. elegans and C. briggsae, and were retained in the C. elegans line, but lost in the C. briggsae line. Further analysis of the two bas-1-like genes in C. elegans suggests that they are unlikely to encode functional enzymes, and may be expressed pseudogenes. Conclusions The bas-1 gene of C. elegans encodes a serotonin- and dopamine-synthetic

  16. Milk synthetic response of the bovine mammary gland to an increase in the local concentration of amino acids and acetate.

    Purdie, N G; Trout, D R; Poppi, D P; Cant, J P

    2008-01-01

    Rates of secretion of components into milk are a function of precursor concentrations and parameters that describe expression of the milk synthetic enzymes and their sensitivity to precursor concentrations. To establish the enzymatic sensitivities of milk fat yield and mammary acetate utilization to circulating acetate concentration, lactating cows were infused for 10 h with 0 or 40 g of acetate/h in an external iliac artery supplying one udder half. In addition, to investigate the possibility that energy supply influences the milk protein response to an elevated amino acid (AA) concentration, 2 different AA profiles were infused with and without acetate. Six cows, fed a total mixed ration of 21% crude protein ad libitum, were infused with AA at 0 g/h, 30 g/h in the profile of rumen microbes, or 30 g/h in the profile of milk proteins, in a 3 x 2 factorial arrangement with the 2 acetate treatments of 0 and 40 g/h, all in a 6 x 6 Latin square. Amino acid infusion caused a 60% increase, on average, in plasma concentration of AA entering the infused udder half. From the microbial AA profile, 49% of infused AA were taken up by the udder half, 42% of which occurred during the first pass. From the milk AA profile, 44% of infused AA were taken up by the udder half, 50% of which occurred during the first pass. There was an 8% increase in yield of milk protein with AA infusion, representing 7% capture, but no effect of the infused profile. Acetate infusion caused a decrease in the yields of milk protein and lactose when AA were infused, but not when AA were absent. Milk fat yields were not affected, although acetate concentrations in plasma entering the infused udder half increased by 123% and mammary uptakes increased by 128%. Mammary uptakes of long-chain fatty acids and beta-hydroxybutyrate were not affected by acetate infusion, whereas glucose uptakes tended to increase. It was suggested that excess acetate may have been sequestered in adipose tissue in the udder. Yields

  17. Self-assembled poly(ethylene glycol)-co-acrylic acid microgels to inhibit bacterial colonization of synthetic surfaces.

    Wang, Qichen; Uzunoglu, Emel; Wu, Yong; Libera, Matthew

    2012-05-01

    We explored the use of self-assembled microgels to inhibit the bacterial colonization of synthetic surfaces both by modulating surface cell adhesiveness at length scales comparable to bacterial dimensions (∼1 μm) and by locally storing/releasing an antimicrobial. Poly(ethylene glycol) [PEG] and poly(ethylene glycol)-co-acrylic acid [PEG-AA] microgels were synthesized by suspension photopolymerization. Consistent with macroscopic gels, a pH dependence of both zeta potential and hydrodynamic diameter was observed in AA-containing microgels but not in pure PEG microgels. The microgels were electrostatically deposited onto poly(l-lysine) (PLL) primed silicon to form submonolayer surface coatings. The microgel surface density could be controlled via the deposition time and the microgel concentration in the parent suspension. In addition to their intrinsic antifouling properties, after deposition, the microgels could be loaded with a cationic antimicrobial peptide (L5) because of favorable electrostatic interactions. Loading was significantly higher in PEG-AA microgels than in pure PEG microgels. The modification of PLL-primed Si by unloaded PEG-AA microgels reduced the short-term (6 h) S. epidermidis surface colonization by a factor of 2, and the degree of inhibition increased when the average spacing between microgels was reduced. Postdeposition L5 peptide loading into microgels further reduced bacterial colonization to the extent that, after 10 h of S. epidermidis culture in tryptic soy broth, the colonization of L5-loaded PEG-AA microgel-modified Si was comparable to the very small level of colonization observed on macroscopic PEG gel controls. The fact that these microgels can be deposited by a nonline-of-sight self-assembly process and hinder bacterial colonization opens the possibility of modifying the surfaces of topographically complex biomedical devices and reduces the rate of biomaterial-associated infection. PMID:22519439

  18. Lowering Bile Acid Pool Size with a Synthetic Farnesoid X Receptor (FXR) Agonist Induces Obesity and Diabetes through Reduced Energy Expenditure*

    Watanabe, Mitsuhiro; Horai, Yasushi; Houten, Sander M; Morimoto, Kohkichi; Sugizaki, Taichi; Arita, Eri; Mataki, Chikage; Sato, Hiroyuki; Tanigawara, Yusuke; Schoonjans, Kristina; Itoh, Hiroshi; Auwerx, Johan

    2011-01-01

    We evaluated the metabolic impact of farnesoid X receptor (FXR) activation by administering a synthetic FXR agonist (GW4064) to mice in which obesity was induced by a high fat diet. Administration of GW4064 accentuated body weight gain and glucose intolerance induced by the high fat diet and led to a pronounced worsening of the changes in liver and adipose tissue. Mechanistically, treatment with GW4064 decreased bile acid (BA) biosynthesis, BA pool size, and energy expenditure, whereas recons...

  19. Amelioration of radiation induced DNA damage and biochemical alterations by Punica Granatum (L) extracts and synthetic ellagic acid in Swiss albino mice

    Radiation therapy has been used in cancer treatment for many decades; Although effective in killing tumor cells, ROS produced in radiotherapy threaten the integrity and survival of surrounding normal cells. ROS are scavenged by radioprotectors before they can interact with biochemical molecules, thus reducing harmful effects of radiation. The pomegranate, Punica granatum L., an ancient, mystical, and highly distinctive fruit, is the predominant member of the Punicaceae family. It is used in several systems of medicine for a variety of ailments. The objective of the present study was to investigate the protective effects of ethanolic extracts of pomegranate whole fruit (EPWF) and seeds (EPS) and Synthetic Ellagic acid (EA) against Electron Beam Radiation (EBR) induced DNA damage and biochemical alterations in Swiss Albino mice. The extracts and synthetic compound were assessed for its radical scavenging property by DPPH radical scavenging and Ferric Reducing Antioxidant Power assays. The animals were treated with 200 mg/kg body wt. of pomegranate extracts and Ellagic acid for 15 days before exposure to 6 Gy of EBR. Radiation induced DNA damage was assessed by comet assay in the peripheral blood lymphocytes of mice. The biochemical estimations were carried out in the serum and RBC lysate of the animals. The plant extracts and synthetic compound exhibited good radical scavenging and reducing properties.The pretreated animals before irradiation caused a reduction in the comet length, olive tail moment, % DNA in tail when compared to irradiated group. The biochemical parameters such as lipid peroxidation was significantly depleted in the treated groups when compared to irradiated group followed by significant elevation in reduced glutathione. Our findings indicate the ameliorating effects of pomegranate extracts and synthetic ellagic acid on radiation induced DNA damage and biochemical changes in mice may be due to its free radical scavenging and increased antioxidant

  20. Morphology and thermal degradation study of poly(lactic acid)/synthetic mica composites; Estudo da morfologia e da degradacao termica de compositos de poli(acido latico)/mica sintetica organofilica

    Souza, D.H.S.; Dias, M.L., E-mail: diegosaboya@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano

    2010-07-01

    Poly(lactic acid) (PLA)/synthetic mica composites has been little studied in the literature. In this work, an organophilic synthetic mica was used to prepare PLA nanocomposites. The composites were obtained at an internal mixer containing 3, 5, 7 and 10 wt% of mica. The materials were analyzed by x-ray diffraction, thermogravimetric analysis and gel permeation chromatography. (author)

  1. Autotaxin, a synthetic enzyme of lysophosphatidic acid (LPA, mediates the induction of nerve-injured neuropathic pain

    Chun Jerold

    2008-02-01

    Full Text Available Abstract Recently, we reported that lysophosphatidic acid (LPA induces long-lasting mechanical allodynia and thermal hyperalgesia as well as demyelination and upregulation of pain-related proteins through one of its cognate receptors, LPA1. In addition, mice lacking the LPA1 receptor gene (lpa1-/- mice lost these nerve injury-induced neuropathic pain behaviors and phenomena. However, since lpa1-/- mice did not exhibit any effects on the basal nociceptive threshold, it is possible that nerve injury-induced neuropathic pain and its machineries are initiated by LPA via defined biosynthetic pathways that involve multiple enzymes. Here, we attempted to clarify the involvement of a single synthetic enzyme of LPA known as autotaxin (ATX in nerve injury-induced neuropathic pain. Wild-type mice with partial sciatic nerve injury showed robust mechanical allodynia starting from day 3 after the nerve injury and persisting for at least 14 days, along with thermal hyperalgesia. On the other hand, heterozygous mutant mice for the autotaxin gene (atx+/-, which have 50% ATX protein and 50% lysophospholipase D activity compared with wild-type mice, showed approximately 50% recovery of nerve injury-induced neuropathic pain. In addition, hypersensitization of myelinated Aβ˜ MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGacaGaaiaabeqaaeqabiWaaaGcbaGafqOSdiMbaGaaaaa@2D83@- or Aδ-fiber function following nerve injury was observed in electrical stimuli-induced paw withdrawal tests using a Neurometer®. The hyperalgesia was completely abolished in lpa1-/- mice, and reduced by 50% in atx+/- mice. Taken together, these findings suggest that LPA biosynthesis through ATX is the source of LPA for LPA1 receptor-mediated neuropathic pain. Therefore, targeted inhibition of ATX-mediated LPA biosynthesis as well as

  2. The complete genome sequence of Natrinema sp. J7-2, a haloarchaeon capable of growth on synthetic media without amino acid supplements.

    Feng, Jie; Liu, Bin; Zhang, Ziqian; Ren, Yan; Li, Yang; Gan, Fei; Huang, Yuping; Chen, Xiangdong; Shen, Ping; Wang, Lei; Tang, Bing; Tang, Xiao-Feng

    2012-01-01

    Natrinema sp. J7-2 is an extreme haloarchaeon capable of growing on synthetic media without amino acid supplements. Here we report the complete genome sequence of Natrinema sp. J7-2 which is composed of a 3,697,626-bp chromosome and a 95,989-bp plasmid pJ7-I. This is the first complete genome sequence of a member of the genus Natrinema. We demonstrate that Natrinema sp. J7-2 can use gluconate, glycerol, or acetate as the sole carbon source and that its genome encodes complete metabolic pathways for assimilating these substrates. The biosynthetic pathways for all 20 amino acids have been reconstructed, and we discuss a possible evolutionary relationship between the haloarchaeal arginine synthetic pathway and the bacterial lysine synthetic pathway. The genome harbors the genes for assimilation of ammonium and nitrite, but not nitrate, and has a denitrification pathway to reduce nitrite to N(2)O. Comparative genomic analysis suggests that most sequenced haloarchaea employ the TrkAH system, rather than the Kdp system, to actively uptake potassium. The genomic analysis also reveals that one of the three CRISPR loci in the Natrinema sp. J7-2 chromosome is located in an integrative genetic element and is probably propagated via horizontal gene transfer (HGT). Finally, our phylogenetic analysis of haloarchaeal genomes provides clues about evolutionary relationships of haloarchaea. PMID:22911826

  3. Sulfuric acid dissolution of 4A and Na-Y synthetic zeolites and effects on Na-Y surface and particle properties

    Wang, Xiaoyu; Wang, Kunping; Plackowski, Chris A.; Nguyen, Anh V.

    2016-03-01

    Sodium rich synthetic zeolites 4A and Na-Y have different silicon-to-aluminium (Si/Al) ratios and are widely used as molecular sieves, catalysts and adsorbents. This study investigates the changes in 4A and Na-Y synthetic zeolites treated by H2SO4 at room temperature. Both zeolite types are examined before and after treatment by following the dissolution and re-crystallisation processes, and Na-Y by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and particle size analysis. Na-Y zeolite (high Si/Al ratio) has stronger acid-resistivity than 4A zeolite (low Si/Al ratio) and can be treated with H2SO4 up to 5 M without complete dissolution, whereas 4A zeolite is completely dissolved by 0.5 M acid. For both zeolites, the treatment generates dissolution (of both Si and Al) of first order fast kinetics, followed by re-crystallization. XRD studies of Na-Y zeolite indicate that acid treatment leads to structural changes where cations are removed and as dissolution progresses de-alumination takes place, thereby altering the main tetrahedral structure. XPS analysis shows the Si/Al atomic ratio for Na-Y zeolite increases from 2.94 at 0 M to 8.18 at 0.1 M, and a significant binding energy (BE) shift of Si and O occurs even at a high Si/Al ratio. The acid treatment increases the surface intermediate electronegativity of Na-Y zeolite, and the BE of each main structural element changes in the same way as the electronegativity ratio (element electronegativity to total surface electronegativity) as the acid concentration increases. Particle size analysis indicates that a recrystallization process occurs during acid treatment, as shown by a shift of the coarse particle distribution peak size to progressively smaller sizes with increasing acid concentration.

  4. Synthetic LNA/DNA nano-scaffolds for highly efficient diagnostics of nucleic acids and autoimmune antibodies

    Astakhova, Irina Kira

    2014-01-01

    Herein novel fluorescent oligonucleotides for homogeneous (all-in-solution) detection of nucleic acids and autoimmune antibodies (autoantibodies) are described. The probes are prepared by highly efficient copper-catalyzed click chemistry between novel alkyne-modified locked nucleic acid (LNA) str...

  5. Dissecting the chemical interactions and substrate structural signatures governing RNA polymerase II trigger loop closure by synthetic nucleic acid analogues

    Xu, Liang; Butler, Kyle Vincent; Chong, Jenny; Wengel, Jesper; Kool, Eric T; Wang, Dong

    2014-01-01

    The trigger loop (TL) of RNA polymerase II (Pol II) is a conserved structural motif that is crucial for Pol II catalytic activity and transcriptional fidelity. The TL remains in an inactive open conformation when the mismatched substrate is bound. In contrast, TL switches from an inactive open...... remains elusive. Here we employed synthetic nucleotide analogues as 'chemical mutation' tools coupling with α-amanitin transcription inhibition assay to systematically dissect the key chemical interactions and structural signatures governing the substrate-coupled TL closure in Saccharomyces cerevisiae Pol...

  6. Direct laser writing of synthetic poly(amino acid) hydrogels and poly(ethylene glycol) diacrylates by two-photon polymerization

    The additive manufacturing technique of direct laser writing by two-photon polymerization (2PP-DLW) enables the fabrication of three-dimensional microstructures with superior accuracy and flexibility. When combined with biomimetic hydrogel materials, 2PP-DLW can be used to recreate the microarchitectures of the extracellular matrix. However, there are currently only a limited number of hydrogels applicable for 2PP-DLW. In order to widen the selection of synthetic biodegradable hydrogels, in this work we studied the 2PP-DLW of methacryloylated and acryloylated poly(α-amino acid)s (poly(AA)s). The performance of these materials was compared to widely used poly(ethylene glycol) diacrylates (PEGdas) in terms of polymerization and damage thresholds, voxel size, line width, post-polymerization swelling and deformation. We found that both methacryloylated and acryloylated poly(AA) hydrogels are suitable to 2PP-DLW with a wider processing window than PEGdas. The poly(AA) with the highest degree of acryloylation showed the greatest potential for 3D microfabrication. - Highlights: • Methacryloylated and acryloylated poly(α-amino acid)s (poly(AA)s) were synthesized. • Direct laser writing by two-photon polymerization (2PP-DLW) of poly(AA)s is shown. • Poly(AA)s have wider processing windows than poly(ethylene glycol) diacrylates. • 3D poly(AA) structures with 80% water content were fabricated

  7. Direct laser writing of synthetic poly(amino acid) hydrogels and poly(ethylene glycol) diacrylates by two-photon polymerization

    Käpylä, Elli, E-mail: elli.kapyla@tut.fi [Department of Electronics and Communications Engineering, Tampere University of Technology, P.O. Box 692, 33101 Tampere (Finland); BioMediTech, Biokatu 10, 33520 Tampere (Finland); Sedlačík, Tomáš [Institute of Macromolecular Chemistry of the Academy of Sciences of the Czech Republic, Heyrovského nám. 2, 162 06 Praha 6, Břevnov, Prague (Czech Republic); Aydogan, Dogu Baran [Department of Electronics and Communications Engineering, Tampere University of Technology, P.O. Box 692, 33101 Tampere (Finland); BioMediTech, Biokatu 10, 33520 Tampere (Finland); Viitanen, Jouko [VTT Technical Research Centre of Finland, P.O. Box 1300, 33101 Tampere (Finland); Rypáček, František [Institute of Macromolecular Chemistry of the Academy of Sciences of the Czech Republic, Heyrovského nám. 2, 162 06 Praha 6, Břevnov, Prague (Czech Republic); Kellomäki, Minna [Department of Electronics and Communications Engineering, Tampere University of Technology, P.O. Box 692, 33101 Tampere (Finland); BioMediTech, Biokatu 10, 33520 Tampere (Finland)

    2014-10-01

    The additive manufacturing technique of direct laser writing by two-photon polymerization (2PP-DLW) enables the fabrication of three-dimensional microstructures with superior accuracy and flexibility. When combined with biomimetic hydrogel materials, 2PP-DLW can be used to recreate the microarchitectures of the extracellular matrix. However, there are currently only a limited number of hydrogels applicable for 2PP-DLW. In order to widen the selection of synthetic biodegradable hydrogels, in this work we studied the 2PP-DLW of methacryloylated and acryloylated poly(α-amino acid)s (poly(AA)s). The performance of these materials was compared to widely used poly(ethylene glycol) diacrylates (PEGdas) in terms of polymerization and damage thresholds, voxel size, line width, post-polymerization swelling and deformation. We found that both methacryloylated and acryloylated poly(AA) hydrogels are suitable to 2PP-DLW with a wider processing window than PEGdas. The poly(AA) with the highest degree of acryloylation showed the greatest potential for 3D microfabrication. - Highlights: • Methacryloylated and acryloylated poly(α-amino acid)s (poly(AA)s) were synthesized. • Direct laser writing by two-photon polymerization (2PP-DLW) of poly(AA)s is shown. • Poly(AA)s have wider processing windows than poly(ethylene glycol) diacrylates. • 3D poly(AA) structures with 80% water content were fabricated.

  8. Post-Stroke Depression Modulation and in Vivo Antioxidant Activity of Gallic Acid and Its Synthetic Derivatives in a Murine Model System.

    Nabavi, Seyed Fazel; Habtemariam, Solomon; Di Lorenzo, Arianna; Sureda, Antoni; Khanjani, Sedigheh; Nabavi, Seyed Mohammad; Daglia, Maria

    2016-01-01

    Gallic acid (3,4,5-trihydroxybenzoic acid, GA) is a plant secondary metabolite, which shows antioxidant activity and is commonly found in many plant-based foods and beverages. Recent evidence suggests that oxidative stress contributes to the development of many human chronic diseases, including cardiovascular and neurodegenerative pathologies, metabolic syndrome, type 2 diabetes and cancer. GA and its derivative, methyl-3-O-methyl gallate (M3OMG), possess physiological and pharmacological activities closely related to their antioxidant properties. This paper describes the antidepressive-like effects of intraperitoneal administration of GA and two synthetic analogues, M3OMG and P3OMG (propyl-3-O-methylgallate), in balb/c mice with post-stroke depression, a secondary form of depression that could be due to oxidative stress occurring during cerebral ischemia and the following reperfusion. Moreover, this study determined the in vivo antioxidant activity of these compounds through the evaluation of superoxide dismutase (SOD) and catalase (Cat) activity, thiobarbituric acid-reactive substances (TBARS) and reduced glutathione (GSH) levels in mouse brain. GA and its synthetic analogues were found to be active (at doses of 25 and 50 mg/kg) in the modulation of depressive symptoms and the reduction of oxidative stress, restoring normal behavior and, at least in part, antioxidant endogenous defenses, with M3OMG being the most active of these compounds. SOD, TBARS, and GSH all showed strong correlation with behavioral parameters, suggesting that oxidative stress is tightly linked to the pathological processes involved in stroke and PSD. As a whole, the obtained results show that the administration of GA, M3OMG and P3OMG induce a reduction in depressive symptoms and oxidative stress. PMID:27136579

  9. Post-Stroke Depression Modulation and in Vivo Antioxidant Activity of Gallic Acid and Its Synthetic Derivatives in a Murine Model System

    Seyed Fazel Nabavi

    2016-04-01

    Full Text Available Gallic acid (3,4,5-trihydroxybenzoic acid, GA is a plant secondary metabolite, which shows antioxidant activity and is commonly found in many plant-based foods and beverages. Recent evidence suggests that oxidative stress contributes to the development of many human chronic diseases, including cardiovascular and neurodegenerative pathologies, metabolic syndrome, type 2 diabetes and cancer. GA and its derivative, methyl-3-O-methyl gallate (M3OMG, possess physiological and pharmacological activities closely related to their antioxidant properties. This paper describes the antidepressive-like effects of intraperitoneal administration of GA and two synthetic analogues, M3OMG and P3OMG (propyl-3-O-methylgallate, in balb/c mice with post-stroke depression, a secondary form of depression that could be due to oxidative stress occurring during cerebral ischemia and the following reperfusion. Moreover, this study determined the in vivo antioxidant activity of these compounds through the evaluation of superoxide dismutase (SOD and catalase (Cat activity, thiobarbituric acid-reactive substances (TBARS and reduced glutathione (GSH levels in mouse brain. GA and its synthetic analogues were found to be active (at doses of 25 and 50 mg/kg in the modulation of depressive symptoms and the reduction of oxidative stress, restoring normal behavior and, at least in part, antioxidant endogenous defenses, with M3OMG being the most active of these compounds. SOD, TBARS, and GSH all showed strong correlation with behavioral parameters, suggesting that oxidative stress is tightly linked to the pathological processes involved in stroke and PSD. As a whole, the obtained results show that the administration of GA, M3OMG and P3OMG induce a reduction in depressive symptoms and oxidative stress.

  10. High dietary level of synthetic vitamin E on lipid peroxidation, membrane fatty acid composition and cytotoxicity in breast cancer xenograft and in mouse host tissue

    Barnes Christopher J

    2003-03-01

    Full Text Available Abstract Background d-α-tocopherol is a naturally occurring form of vitamin E not previously known to have antitumor activity. Synthetic vitamin E (sE is a commonly used dietary supplement consisting of a mixture of d-α-tocopherol and 7 equimolar stereoisomers. To test for antilipid peroxidation and for antitumor activity of sE supplementation, two groups of nude mice bearing a MDA-MB 231 human breast cancer tumor were fed an AIN-76 diet, one with and one without an additional 2000 IU/kg dry food (equivalent to 900 mg of all-rac-α-tocopherol or sE. This provided an intake of about 200 mg/kg body weight per day. The mice were killed at either 2 or 6 weeks after the start of dietary intervention. During necropsy, tumor and host tissues were excised for histology and for biochemical analyses. Results Tumor growth was significantly reduced by 6 weeks of sE supplementation. Thiobarbituric acid reactive substances, an indicator of lipid peroxidation, were suppressed in tumor and in host tissues in sE supplemented mice. In the sE treated mice, the fatty acid composition of microsomal and mitochondrial membranes of tumor and host tissues had proportionately less linoleic acid (n-6 C 18-2, similar levels of arachidonic acid (n-6 C 20-4, but more docosahexanoic acid (n-3 C 22-6. The sE supplementation had no significant effect on blood counts or on intestinal histology but gave some evidence of cardiac toxicity as judged by myocyte vacuoles and by an indicator of oxidative stress (increased ratio of Mn SOD mRNA over GPX1 mRNA. Conclusions At least one of the stereoisomers in sE has antitumor activity. Synthetic vitamin E appears to preferentially stabilize membrane fatty acids with more double bonds in the acyl chain. Although sE suppressed tumor growth and lipid peroxidation, it may have side-effects in the heart.

  11. Expression of Vibrio harveyi Acyl-ACP Synthetase Allows Efficient Entry of Exogenous Fatty Acids into the Escherichia coli Fatty Acid and Lipid A Synthetic Pathways

    Jiang, Yanfang; Morgan-Kiss, Rachael M.; Campbell, John W.; Chan, Chi Ho; Cronan, John E.

    2010-01-01

    Although the Escherichia coli fatty acid synthesis (FAS) pathway is the best studied type II fatty acid synthesis system, a major experimental limitation has been the inability to feed intermediates into the pathway in vivo because exogenously-supplied free fatty acids are not efficiently converted to the acyl-acyl carrier protein (ACP) thioesters required by the pathway. We report that expression of Vibrio harveyi acyl-ACP synthetase (AasS), a soluble cytosolic enzyme that ligates free fatty acids to ACP to form acyl-ACPs, allows exogenous fatty acids to enter the E. coli fatty acid synthesis pathway. The free fatty acids are incorporated intact and can be elongated or directly incorporated into complex lipids by acyltransferases specific for acyl-ACPs. Moreover, expression of AasS strains and supplementation with the appropriate fatty acid restored growth to E. coli mutant strains that lack essential fatty acid synthesis enzymes. Thus, this strategy provides a new tool for circumventing the loss of enzymes essential for FAS function. PMID:20028080

  12. Post-synthetic preparation of Sn-, Ti- and Zr-beta: a facile route to water tolerant, highly active Lewis acidic zeolites.

    Wolf, Patrick; Hammond, Ceri; Conrad, Sabrina; Hermans, Ive

    2014-03-21

    A two-step procedure for the post-synthetic preparation of Lewis acidic Sn-, Zr- and Ti-zeolite β is reported. Dealumination of a commercially available Al-β zeolite leads to the formation of highly siliceous material containing silanol nests, which can be filled in a second step via the solid-state ion-exchange or impregnation of an appropriate metal precursor. Spectroscopic studies indicate that each metal is subsequently coordinated within the zeolite framework, and that little or no bulk oxides are formed--despite the high metal loadings. The synthesised catalysts demonstrate excellent activity for the isomerisation of glyceraldehyde to dihydroxyacetone, a key model reaction for the upgrading of bio-renewable feedstocks, and the epoxidation of bulky olefins. PMID:24407516

  13. A calorimetric study of the kinetics and thermodynamics of the attack of synthetic fluorapatite by mixtures of sulfuric and phosphoric acids is undertaken at 25 deg. C

    A calorimetric study of the kinetics and thermodynamics of the attack of synthetic fluorapatite by mixtures of sulfuric and phosphoric acids is undertaken at 25 deg.. C. The global enthalpy of the attack equals -407.0 kJ/mol. Interpretation of the calorimeteric results by Avrami model shows the existence of two steps. The first is attributed to the dissolution of the solid, and the second to precipitation of gypsum. The deconvoluted curves were analysed iteratively to obtain the kinetic parameters and the enthalpy of precipitation. The later quantity does not differ from the experimental value by more than 2.3% and the reaction order equals 2 and 0.5 for calcium and sulphate ions respectively

  14. Design, synthesis and evaluation of semi-synthetic triazole-containing caffeic acid analogues as 5-lipoxygenase inhibitors.

    De Lucia, Daniela; Lucio, Oscar Méndez; Musio, Biagia; Bender, Andreas; Listing, Monika; Dennhardt, Sophie; Koeberle, Andreas; Garscha, Ulrike; Rizzo, Roberta; Manfredini, Stefano; Werz, Oliver; Ley, Steven V

    2015-08-28

    In this work the synthesis, structure-activity relationship (SAR) and biological evaluation of a novel series of triazole-containing 5-lipoxygenase (5-LO) inhibitors are described. The use of structure-guided drug design techniques provided compounds that demonstrated excellent 5-LO inhibition with IC50 of 0.2 and 3.2 μm in cell-based and cell-free assays, respectively. Optimization of binding and functional potencies resulted in the identification of compound 13d, which showed an enhanced activity compared to the parent bioactive compound caffeic acid 5 and the clinically approved zileuton 3. Compounds 15 and 16 were identified as lead compounds in inhibiting 5-LO products formation in neutrophils. Their interference with other targets on the arachidonic acid pathway was also assessed. Cytotoxicity tests were performed to exclude a relationship between cytotoxicity and the increased activity observed after structure optimization. PMID:26197161

  15. Insulinotropic and Muscle Protein Synthetic Effects of Branched-Chain Amino Acids: Potential Therapy for Type 2 Diabetes and Sarcopenia

    Darren G. Candow

    2012-11-01

    Full Text Available The loss of muscle mass and strength with aging (i.e., sarcopenia has a negative effect on functional independence and overall quality of life. One main contributing factor to sarcopenia is the reduced ability to increase skeletal muscle protein synthesis in response to habitual feeding, possibly due to a reduction in postprandial insulin release and an increase in insulin resistance. Branched-chain amino acids (BCAA, primarily leucine, increases the activation of pathways involved in muscle protein synthesis through insulin-dependent and independent mechanisms, which may help counteract the “anabolic resistance” to feeding in older adults. Leucine exhibits strong insulinotropic characteristics, which may increase amino acid availability for muscle protein synthesis, reduce muscle protein breakdown, and enhance glucose disposal to help maintain blood glucose homeostasis.

  16. Supramolecular Arrangement in Styphnic Acid and Naphthalene-1,4-diol (1 : 1 through a Novel Synthetic Rote for Styphnic Acid

    Moamen S. Refat

    2013-01-01

    Full Text Available The chemical preparation and crystal structure of styphnic acid and naphthalene-1,4-diol (1 : 1 (I have been reported. The compound crystallizes in the orthorhombic system in space group Pnma and cell parameters a=6.6712(2, b=16.8267(7, c=13.6450(5 Å and V=1531.71(10 Å3, and Z=4. Crystal structure has been determined and refined to R=0.0576. The crystal structure of I, the asymmetric unit, contains C6H2N3O7, C10H7O, and it is a half portion of both styphnic acid and naphthalene-1,4-diol. The O1–H1⋯O2 intramolecular hydrogen bond was found between the O–H and a nitro group in the styphnic acid unit.

  17. Protective effect of minocycline, a semi-synthetic second-generation tetracycline against 3-nitropropionic acid (3-NP)-induced neurotoxicity

    3-Nitropropionic acid (3-NP) is an irreversible inhibitor of the electron transport enzyme succinate dehydrogenase, a mitochondrial Complex II enzyme. Minocycline is a semi-synthetic second-generation tetracycline with neuroprotective activity and has the capability to effectively cross the blood-brain barrier. We investigated the effects of minocycline on behavioral, biochemical, inflammation related and neurochemical alterations induced by the sub-chronic administration of 3-nitropropionic acid to rats. Chronic pre-administration of minocycline (50 and 100 mg/kg) dose dependently prevented 3-NP-induced dysfunction behavioral (hypoactivity, memory retention, locomotor and rota-rod activity). In addition, 3-NP produced a marked increase in lipid peroxidation levels whereas decreased the activities of catalase and succinate dehydrogenase. In contrast, pretreatment of 3-NP injected rats with minocycline resulted in the attenuation of all these alterations. A marked increase in an inflammatory cytokine TNF-α by 3-NP was also decreased by minocycline treatment. Neurochemically, the administration of 3-NP significantly decreased the levels of catecholamines in the brain homogenates (dopamine, norepinephrine and serotonin) which were reversed by pretreatment of minocycline. The present finding explains the neuroprotective effect of minocycline against 3-NP toxicity by virtue of its antioxidant and anti-inflammatory activity

  18. Protective effect of minocycline, a semi-synthetic second-generation tetracycline against 3-nitropropionic acid (3-NP)-induced neurotoxicity.

    Ahuja, Manuj; Bishnoi, Mahendra; Chopra, Kanwaljit

    2008-02-28

    3-Nitropropionic acid (3-NP) is an irreversible inhibitor of the electron transport enzyme succinate dehydrogenase, a mitochondrial Complex II enzyme. Minocycline is a semi-synthetic second-generation tetracycline with neuroprotective activity and has the capability to effectively cross the blood-brain barrier. We investigated the effects of minocycline on behavioral, biochemical, inflammation related and neurochemical alterations induced by the sub-chronic administration of 3-nitropropionic acid to rats. Chronic pre-administration of minocycline (50 and 100mg/kg) dose dependently prevented 3-NP-induced dysfunction behavioral (hypoactivity, memory retention, locomotor and rota-rod activity). In addition, 3-NP produced a marked increase in lipid peroxidation levels whereas decreased the activities of catalase and succinate dehydrogenase. In contrast, pretreatment of 3-NP injected rats with minocycline resulted in the attenuation of all these alterations. A marked increase in an inflammatory cytokine TNF-alpha by 3-NP was also decreased by minocycline treatment. Neurochemically, the administration of 3-NP significantly decreased the levels of catecholamines in the brain homogenates (dopamine, norepinephrine and serotonin) which were reversed by pretreatment of minocycline. The present finding explains the neuroprotective effect of minocycline against 3-NP toxicity by virtue of its antioxidant and anti-inflammatory activity. PMID:18164115

  19. bba, a synthetic derivative of 23-hydroxybutulinic acid, reverses multidrug resistance by inhibiting the efflux activity of MRP7 (ABCC10.

    Jun-Jiang Chen

    Full Text Available Natural products are frequently used for adjuvant chemotherapy in cancer treatment. 23-O-(1,4'-bipiperidine-1-carbonyl betulinic acid (BBA is a synthetic derivative of 23-hydroxybutulinic acid (23-HBA, which is a natural pentacyclic triterpene and the major active constituent of the root of Pulsatillachinensis. We previously reported that BBA could reverse P-glycoprotein (P-gp/ABCB1-mediated multidrug resistance (MDR. In the present study, we investigated whether BBA has the potential to reverse multidrug resistance protein 7 (MRP7/ABCC10-mediated MDR. We found that BBA concentration-dependently enhanced the sensitivity of MRP7-transfected HEK293 cells to paclitaxel, docetaxel and vinblastine. Accumulation and efflux experiments demonstrated that BBA increased the intracellular accumulation of [(3H]-paclitaxel by inhibiting the efflux of [(3H]-paclitaxel from HEK293/MRP7 cells. In addition, immunoblotting and immunofluorescence analyses indicated no significant alteration of MRP7 protein expression and localization in plasma membranes after treatment with BBA. These results demonstrate that BBA reverses MRP7-mediated MDR through blocking the drug efflux function of MRP7 without affecting the intracellular ATP levels. Our findings suggest that BBA has the potential to be used in combination with conventional chemotherapeutic agents to augment the response to chemotherapy.

  20. Assignment of hexuronic acid stereochemistry in synthetic heparan sulfate tetrasaccharides with 2-O-sulfo uronic acids using electron detachment dissociation

    Agyekum, Isaac; Patel, Anish B.; Zong, Chengli; Boons, Geert Jan; Amster, I. Jonathan

    2015-01-01

    The present work focuses on the assignment of uronic acid stereochemistry in heparan sulfate (HS) oligomers. The structural elucidation of HS glycosaminoglycans is the subject of considerable importance due to the biological and biomedical significance of this class of carbohydrates. They are highly

  1. Synthetic Cyclolipopeptides Selective against Microbial, Plant and Animal Cell Targets by Incorporation of D-Amino Acids or Histidine

    Vilà, Sílvia; Badosa, Esther; Montesinos, Emilio; Planas, Marta; Feliu, Lidia

    2016-01-01

    Cyclolipopeptides derived from the antimicrobial peptide c(Lys-Lys-Leu-Lys-Lys-Phe-Lys-Lys-Leu-Gln) (BPC194) were prepared on solid-phase and screened against four plant pathogens. The incorporation at Lys5 of fatty acids of 4 to 9 carbon atoms led to active cyclolipopeptides. The influence on the antimicrobial activity of the Lys residue that is derivatized was also evaluated. In general, acylation of Lys1, Lys2 or Lys5 rendered the sequences with the highest activity. Incorporation of a D-amino acid maintained the antimicrobial activity while significantly reduced the hemolysis. Replacement of Phe with a His also yielded cyclolipopeptides with low hemolytic activity. Derivatives exhibiting low phytotoxicity in tobacco leaves were also found. Interestingly, sequences with or without significant activity against phytopathogenic bacteria and fungi, but with differential hemolysis and phytotoxicity were identified. Therefore, this study represents an approach to the development of bioactive peptides with selective activity against microbial, plant and animal cell targets. These selective cyclolipopeptides are candidates useful not only to combat plant pathogens but also to be applied in other fields. PMID:27008420

  2. Synthetic environments

    Lukes, George E.; Cain, Joel M.

    1996-02-01

    The Advanced Distributed Simulation (ADS) Synthetic Environments Program seeks to create robust virtual worlds from operational terrain and environmental data sources of sufficient fidelity and currency to interact with the real world. While some applications can be met by direct exploitation of standard digital terrain data, more demanding applications -- particularly those support operations 'close to the ground' -- are well-served by emerging capabilities for 'value-adding' by the user working with controlled imagery. For users to rigorously refine and exploit controlled imagery within functionally different workstations they must have a shared framework to allow interoperability within and between these environments in terms of passing image and object coordinates and other information using a variety of validated sensor models. The Synthetic Environments Program is now being expanded to address rapid construction of virtual worlds with research initiatives in digital mapping, softcopy workstations, and cartographic image understanding. The Synthetic Environments Program is also participating in a joint initiative for a sensor model applications programer's interface (API) to ensure that a common controlled imagery exploitation framework is available to all researchers, developers and users. This presentation provides an introduction to ADS and the associated requirements for synthetic environments to support synthetic theaters of war. It provides a technical rationale for exploring applications of image understanding technology to automated cartography in support of ADS and related programs benefitting from automated analysis of mapping, earth resources and reconnaissance imagery. And it provides an overview and status of the joint initiative for a sensor model API.

  3. Impact of structural aberrancy of polysialic acid and its synthetic enzyme ST8SIA2 in schizophrenia

    Chihiro eSato

    2013-05-01

    Full Text Available Psychiatric disorders are a group of human diseases that impair higher cognitive functions. Whole-genomic analyses have recently identified susceptibility genes for several psychiatric disorders, including schizophrenia. Among the genes reported to be involved in psychiatric disorders, a gene encoding a polysialyltransferase involved in the biosynthesis of polysialic acid (polySia or PSA on cell surfaces has attracted attention for its potential role in emotion, learning, memory, circadian rhythm, and behaviors. PolySia is a unique polymer that spatio-temporally modifies neural cell adhesion molecule (NCAM and is predominantly found in embryonic brains, although it persists in areas of the adult brain where neural plasticity, remodeling of neural connections, or neural generation is ongoing, such as the hippocampus, subventricular zone, thalamus, prefrontal cortex, and amygdala. PolySia is thought to be involved in the regulation of cell-cell interactions; however, recent evidence suggests that it is also involved in the functional regulation of ion channels and neurologically active molecules, such as BDNF, FGF2, and dopamine that are deeply involved in psychiatric disorders. In this review, the possible involvement of polysialyltransferase (ST8SIA2/ST8SiaII/STX/Siat8B and its enzymatic product, polySia, in schizophrenia is discussed.

  4. Inhibition of lactate transport in Ehrlich ascites tumor cells and human erythrocytes by a synthetic anhydride of lactic acid.

    Johnson, J H; Belt, J A; Dubinsky, W P; Zimniak, A; Racker, E

    1980-08-01

    The synthesis and some of the physical and biological characteristics of a new inhibitor of lactate transport are described. The inhibitor is isobutylcarbonyl lactayl anhydride (iBCLA). It is formed by the condensation of lactic acid and isobutylchloroformate. It inhibits lactate transport 50% at 0.5 microgram/mg of protein in both Ehrlich ascites tumor cells and human erythrocytes. In contrast, 15 microgram of iBCLA/mg of protein is required for 50% inhibition of phosphate transport in erythrocytes, and phosphate transport in Ehrlich ascites tumor cells is unaffected at levels as high as 50 microgram of iBCLA/mg of protein. A time-dependent and concentration-dependent reversal of lactate transport inhibition took place on exposure of iBCLA-treated Ehrlich ascites cells to hydroxylamine or dithiothreitol. These data, along with the observed sensitivity of the lactate transporter to sulfhydryl reagents [Spencer, T. L., & Lehninger, A. L. (1976) Biochem. J. 154, 405-414], suggest that iBCLA acylates an essential sulfhydryl group on the transporter. When glycolyzing Ehrlich ascites tumor cells were treated with concentrations of iBCLA sufficient for complete inhibition of lactate transport, intracellular lactate levels increased, intracellular pH and extra-cellular lactate levels decreased, and overall lactate production was inhibited. PMID:7407072

  5. Synthetic Rutile

    This work is about the laboratory scale investigation of the conditions in the rutile synthetic production from one me nita in Aguas Dulces reservoir. The iron mineral is chlorinated and volatilized selectively leaving a residue enriched in titanium dioxide which can be used as a substitute of rutile mineral

  6. Synthetic DNA

    O’ Driscoll, Aisling; Sleator, Roy D.

    2013-01-01

    With world wide data predicted to exceed 40 trillion gigabytes by 2020, big data storage is a very real and escalating problem. Herein, we discuss the utility of synthetic DNA as a robust and eco-friendly archival data storage solution of the future.

  7. Pulmonary lung surfactant synthetic peptide concentration-dependent modulation of DPPC and POPG acyl chain order in a DPPC:POPG:palmitic acid lipid mixture.

    Krill, S L; Gupta, S L; Smith, T

    1994-05-01

    Lung surfactant-associated protein interaction with lipid matrices and the effects on lipid thermotropic phase behavior are areas of active research. Many studies limit the lipids to a single or two-component system. The current investigation utilizes a three-lipid component matrix (DPPC:POPG:palmitic acid) to investigate the impact of a synthetic surfactant protein B fragment (SP-B 53-78 DiACM) on the dynamic surface activity of the lipid admixture as measured by a Wilhelmy surface balance. Also, the modulation of the individual lipid acyl chain order by the peptide within the lipid matrix is studied through the use of thermal perturbation FTIR spectroscopy. The data clearly demonstrate a concentration-dependent effect of the peptide on the surface activity with an improvement in the dynamic surface tension diagram characteristics (decreased surface tension and increased collapse plateau) especially at low, 0.36 M%, peptide concentrations. These effects are diminished upon further addition of the peptide. FTIR spectral data demonstrate that the peptide addition results in a significant increase in the acyl chain order of the DPPC and POPG components as measured by the position of the methylene stretching vibrational bands. DPPC is most sensitive to the peptide presence, while the palmitic acid is least affected. The transition temperatures of the individual lipids are also increased with the addition of the peptide. The presence of POPG in the matrix achieves the surface activity similarly seen with natural lung surfactant relative to a DPPC/palmitic acid lipid matrix alone. Its presence increases the sensitivity of the DPPC acyl chains to the presence of the peptide. These effects on the chain order are most probably related to the increased acyl chain fluidity which POPG imparts to the lipid matrix because of the presence of the cis double bond. The phosphatidylglycerol headgroup also adds a negative charge to the lipid matrix which enhances the peptide

  8. Direct and remarkably efficient conversion of methane into acetic acid catalyzed by amavadine and related vanadium complexes. A synthetic and a theoretical DFT mechanistic study.

    Kirillova, Marina V; Kuznetsov, Maxim L; Reis, Patrícia M; da Silva, José A L; da Silva, João J R Fraústo; Pombeiro, Armando J L

    2007-08-29

    Vanadium(IV or V) complexes with N,O- or O,O-ligands, i.e., [VO{N(CH2CH2O)3}], Ca[V(HIDPA)2] (synthetic amavadine), Ca[V(HIDA)2], or [Bu4N]2[V(HIDA)2] [HIDPA, HIDA = basic form of 2,2'-(hydroxyimino)dipropionic or -diacetic acid, respectively], [VO(CF3SO3)2], Ba[VO(nta)(H2O)]2 (nta = nitrilotriacetate), [VO(ada)(H2O)] (ada = N-2-acetamidoiminodiacetate), [VO(Hheida)(H2O)] (Hheida = 2-hydroxyethyliminodiacetate), [VO(bicine)] [bicine = basic form of N,N-bis(2-hydroxyethyl)glycine], and [VO(dipic)(OCH2CH3)] (dipic = pyridine-2,6-dicarboxylate), are catalyst precursors for the efficient single-pot conversion of methane into acetic acid, in trifluoroacetic acid (TFA) under moderate conditions, using peroxodisulfate as oxidant. Effects on the yields and TONs of various factors are reported. TFA acts as a carbonylating agent and CO is an inhibitor for some systems, although for others there is an optimum CO pressure. The most effective catalysts (as amavadine) bear triethanolaminate or (hydroxyimino)dicarboxylates and lead, in a single batch, to CH3COOH yields > 50% (based on CH4) or remarkably high TONs up to 5.6 x 103. The catalyst can remain active upon multiple recycling of its solution. Carboxylation proceeds via free radical mechanisms (CH3* can be trapped by CBrCl3), and theoretical calculations disclose a particularly favorable process involving the sequential formation of CH3*, CH3CO*, and CH3COO* which, upon H-abstraction (from TFA or CH4), yields acetic acid. The CH3COO* radical is formed by oxygenation of CH3CO* by a peroxo-V complex via a V{eta1-OOC(O)CH3} intermediate. Less favorable processes involve the oxidation of CH3CO* by the protonated (hydroperoxo) form of that peroxo-V complex or by peroxodisulfate. The calculations also indicate that (i) peroxodisulfate behaves as a source of sulfate radicals which are methane H-abstractors, as a peroxidative and oxidizing agent for vanadium, and as an oxidizing and coupling agent for CH3CO* and that (ii) TFA is

  9. The synthetic retinoid AGN 193109 but not retinoic acid elevates CYP1A1 levels in mouse embryos and Hepa-1c1c7 cells.

    Soprano, D R; Gambone, C J; Sheikh, S N; Gabriel, J L; Chandraratna, R A; Soprano, K J; Kochhar, D M

    2001-07-15

    The synthetic retinoid AGN 193109 is a potent pan retinoic acid receptor (RAR) antagonist. Treatment of pregnant mice with a single oral 1 mg/kg dose of this antagonist on day 8 postcoitum results in severe craniofacial (median cleft face or frontonasal deficiency) and eye malformations in virtually all exposed fetuses. Using differential display analysis, we have determined that CYP1A1 mRNA levels are elevated in mouse embryos 6 h following treatment with AGN 193109. Similarly, an elevation in CYP1A1 mRNA levels, protein levels, and aryl hydrocarbon hydoxylase activity occurs in Hepa-1c1c7 cells, with the maximal elevation observed when the cells were treated with 10(-5) M AGN 193109 for 4 to 8 h. Elevation in CYP1A1 mRNA levels in mouse embryos and Hepa-1c1c7 cells does not occur upon treatment with the natural retinoid, all-trans-retinoic acid. Finally, elevation in CYP1A1 mRNA levels was not observed when mutant Hepa-1c1c7 cells, which are defective in either the aryl hydrocarbon receptor (AhR) or aryl hydrocarbon receptor nuclear translocator (ARNT), were treated with AGN 193109. This suggests that the AhR/ARNT pathway and not the RAR/RXR pathway is mediating the elevation of CYP1A1 mRNA levels by AGN 193109, at least in the Hepa-1c1c7 cells. This is the first example of a retinoid that displays the abililty to regulate both the RAR/RXR and AhR/ARNT transcriptional regulatory pathways. PMID:11446831

  10. Toxicity of synthetic herbicides containing 2,4-D and MCPA moieties towards Pseudomonas putida mt-2 and its response at the level of membrane fatty acid composition.

    Piotrowska, Aleksandra; Syguda, Anna; Chrzanowski, Łukasz; Heipieper, Hermann J

    2016-02-01

    One of the attempts to create more effective herbicidal compounds includes the use of ionic liquids. Herbicidal ionic liquids have more effective biological activity, they are less volatile, more thermally stable, and exhibit superior efficiency in comparison to typically employed herbicides, allowing the reduction of the herbicide dose applied per hectare. However, studies on the environmental toxicity of this group of compounds are very rarely available. Environmental toxicity is an important factor, showing the concentration of compounds that has negative effects on soil bacteria including those responsible for biodegradation processes. Therefore, potential toxicity of four herbicidal ionic liquids (HILs) precursors containing 2,4-D and MCPA moieties was tested with the well investigated model organism for toxicity and adaptation, Pseudomonas putida mt-2. Results were compared to those obtained for commercial 2,4-D and MCPA herbicides. Next to growth inhibition, given as EC50, changes in the isomerisation of cis to trans unsaturated fatty acids were applied as proxy for cellular stress adaptation to toxic substances. The results revealed that all investigated precursors of HILs showed lower toxicity compared to commercialized synthetic herbicides 2,4-D and MCPA. The collected data on toxicity of HILs together with their physico-chemical properties might be useful for assessing the potential risk of the environmental pollution as well as guidelines for setting the legislation for their future use. PMID:26347932

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

    Shahzad, Sohail; Shahzadi, Lubna; Mahmood, Nasir; Siddiqi, Saadat Anwar; Rauf, Abdul; Manzoor, Faisal; Chaudhry, Aqif Anwar; Rehman, Ihtesham Ur; Yar, Muhammad

    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 (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. PMID:27207049

  12. Synthetic chromosomes.

    Schindler, Daniel; Waldminghaus, Torsten

    2015-11-01

    What a living organism looks like and how it works and what are its components-all this is encoded on DNA, the genetic blueprint. Consequently, the way to change an organism is to change its genetic information. Since the first pieces of recombinant DNA have been used to transform cells in the 1970s, this approach has been enormously extended. Bigger and bigger parts of the genetic information have been exchanged or added over the years. Now we are at a point where the construction of entire chromosomes becomes a reachable goal and first examples appear. This development leads to fundamental new questions, for example, about what is possible and desirable to build or what construction rules one needs to follow when building synthetic chromosomes. Here we review the recent progress in the field, discuss current challenges and speculate on the appearance of future synthetic chromosomes. PMID:26111960

  13. Synthetic jet

    Dančová, P.; Trávníček, Zdeněk; Vít, T.

    Praha: Institute of Thermomechanics AS CR, v. v. i., 2007 - (Zolotarev, I.), s. 35-36 ISBN 978-80-87012-06-2. [Engineering Mechanics 2007: national conference with international participation. Svratka (CZ), 14.05.2007-17.05.2007] R&D Projects: GA ČR GA101/05/2681 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jets * zero-net-mass-flux jet * flow control Subject RIV: BK - Fluid Dynamics

  14. Natural - synthetic - artificial!

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  15. Changes in Renal Function and Oxidative Status Associated with the Hypotensive Effects of Oleanolic Acid and Related Synthetic Derivatives in Experimental Animals.

    Hlengiwe Pretty Madlala

    Full Text Available The triterpene oleanolic acid (OA is known to possess antihypertensive actions. In the present study we to compared the effects of the triterpene on mean arterial blood pressure (MAP and kidney function following acute administration in normotensive animals with those of its related oleanane synthetic derivatives (brominated oleanolic acid, Br-OA and oleanolic acid methyl ester, Me-OA. We also used experimental models of hypertension to further explore the effects of sub-chronic oral OA treatment and evaluated influences on oxidative status.OA was extracted from dried flower buds of Syzygium aromaticum using a previously validated protocol in our laboratory. Me-OA and Br-OA were synthesized according to a method described. Rats were supplemented with lithium chloride (12 mmol L-1 prior to experimentation in order to raise plasma lithium to allow measurements of lithium clearance and fractional excretion (FELi as indices of proximal tubular Na+ handling. Anaesthetized animals were continuously infused via the right jugular with 0.077M NaCl. MAP was measured via a cannula inserted in the carotid artery, and urine was collected through a cannula inserted in the bladder. After a 3.5 h equilibration, MAP, urine flow, electrolyte excretion rates were determined for 4 h of 1 h control, 1.5 h treatment and 1.5 h recovery periods. OA, Me-OA and Br-OA were added to the infusate during the treatment period. We evaluated sub-chronic effects on MAP and kidney function in normotensive Wistar rats and in two animal models of hypertension, spontaneously hypertensive rats (SHR and Dahl salt-sensitive (DSS rats, during 9-week administration of OA (p.o.. Tissue oxidative status was examined in these animals at the end of the study. Increasing evidence suggests that and renal function disturbances and oxidative stress play major roles in the pathogenesis of hypertension.Acute infusion OA and oleanane derivatives displayed qualitatively similar effects in decreasing

  16. Synthetic Brainbows

    Wan, Y.

    2013-06-01

    Brainbow is a genetic engineering technique that randomly colorizes cells. Biological samples processed with this technique and imaged with confocal microscopy have distinctive colors for individual cells. Complex cellular structures can then be easily visualized. However, the complexity of the Brainbow technique limits its applications. In practice, most confocal microscopy scans use different florescence staining with typically at most three distinct cellular structures. These structures are often packed and obscure each other in rendered images making analysis difficult. In this paper, we leverage a process known as GPU framebuffer feedback loops to synthesize Brainbow-like images. In addition, we incorporate ID shuffing and Monte-Carlo sampling into our technique, so that it can be applied to single-channel confocal microscopy data. The synthesized Brainbow images are presented to domain experts with positive feedback. A user survey demonstrates that our synthetic Brainbow technique improves visualizations of volume data with complex structures for biologists.

  17. Uncovering the method of production and detection of synthetic acetic acid adulteration in vinegar by tandem use of 14C liquid scintillation counting and 13C/12C ratio mass spectrometry

    Fraudulent adulteration and or misrepresentation had been a problem for commercial vinegar in the Philippines. Solutions of synthetic acetic acid mixed with colorants and flavour enhancers have been marketed as vinegar. Philippine regulations prohibit the sale of these vinegars produced by non-biogenic means as well as misrepresentation of the fine natural vinegars with cheaper version produced using lower value raw materials. The lack of reliable analytical tools however, has hampered the proper implementation of these laws. In this study, authentic vinegar samples were acquired, which were prepared by natural fermentation of : sugar cane, pineapple juice, and mango juice. Another type of cane vinegar was prepared by fermentation of cane sugar using acetator. Commercial vinegar samples, purchased from major supermarkets in the Philippines, were likewise obtained. Calcium acetate was produced by reaction of distilled vinegar samples with calcium carbonate, and subsequent drying of the resulting solution. Portions of the calcium acetate derived from the samples,were reacted with pyrophosphoric acid in a reflux and the glacial acetic acid was recovered by distillation under reduced pressure. The recovered glacial acetic acid were reconstituted to 90 % v/v. The acetic solutions were mixed with an Optiphase Hisafe Scintillant in vials. The C14 activities of the samples were measured in a 1414 Wallac Scintillation Counter and expressed as disintegrations per gram carbon or dpm/g C. Biogenic samples exhibit 12-15 dpm/g C activities, while synthetic samples show 0-2 dpm/g C activities. The remaining portions of the calcium acetate powder were placed in evacuated glass ampoules containing potassium peroxidisulfate and silver (1) permanganate. The samples inside the ampoules were oxidized to Carbon Dioxide, CO2 gas, in a furnace. The CO2 were then purified and bled to an Isotope Ratio mass spectrometer. 13C/12C ratios were determined and compared against a standard CO2 gas

  18. Synthetic biology, inspired by synthetic chemistry

    Malinova, V; Nallani, M.; Meier, W. P.; Sinner, E. K.

    2012-01-01

    The topic synthetic biology appears still as an 'empty basket to be filled'. However, there is already plenty of claims and visions, as well as convincing research strategies about the theme of synthetic biology. First of all, synthetic biology seems to be about the engineering of biology -about bottom-up and top-down approaches, compromising complexity versus stability of artificial architectures, relevant in biology. Synthetic biology accounts for heterogeneous approaches towards minimal an...

  19. Upgrading protein synthesis for synthetic biology

    O’Donoghue, Patrick; Ling, Jiqiang; Wang, Yane-Shih; Söll, Dieter

    2013-01-01

    Genetic code expansion for synthesis of proteins containing noncanonical amino acids is a rapidly growing field in synthetic biology. Creating optimal orthogonal translation systems will require re-engineering central components of the protein synthesis machinery on the basis of a solid mechanistic biochemical understanding of the synthetic process.

  20. Pharmacokinetics in Wistar Rats of 5-[(4-Carboxybutanoyl)Amino]-2-Hydroxybenzoic Acid: A Novel Synthetic Derivative of 5-Aminosalicylic Acid (5-ASA) with Possible Anti-Inflammatory Activity

    Correa-Basurto, José; Rosales Hernández, Martha Cecilia; Padilla Martínez, Itzia Irene; Mendieta-Wejebe, Jessica Elena

    2016-01-01

    5-[(4-carboxybutanoyl)amino]-2-hydroxybenzoic acid (C2) is a novel synthetic derivative of 5-aminosalicylic acid (5-ASA), which is currently being evaluated ex vivo as an anti-inflammatory agent and has shown satisfactory results. This study aimed to obtain the pharmacokinetic profiles, tissue distribution and plasma protein binding of C2 in Wistar Rats. Additionally, an HPLC method was developed and validated to quantify C2 in rat plasma. The pharmacokinetic profiles of intragastric, intravenous and intraperitoneal administration routes at singles doses of 100, 50, and 100 mg/kg, respectively, were studied in Wistar rats. The elimination half-life of intravenously administered C2 was approximately 33 min. The maximum plasma level of C2 was reached approximately 24 min after intragastric administration, with a Cmax value of 2.5 g/mL and an AUCtot value of 157 μg min-1/mL; the oral bioavailability was approximately 13%. Following a single intragastric or oral dose (100 mg/kg), C2 was distributed and detected in all examined tissues (including the brain and colon). The results showed that C2 accumulates over time. The plasma protein binding results indicated that the unbound fraction of C2 at concentrations of 1 to 20 μg/mL ranged from 89.8% to 92.5%, meaning that this fraction of C2 is available to cross tissues. Finally, the blood-plasma partitioning (BP ratio) of C2 in rat plasma was 0.71 and 0.6 at concentrations of 5 and 10 μg/mL, respectively, which indicates that C2 is free in the plasmatic phase and not inside blood cells. The results of this study suggest that a fraction of the administered C2 dose is absorbed in the stomach, and the fraction that is not absorbed reaches the small intestine and colon. This distribution constitutes the main advantage of C2 compared with 5-ASA for the treatment of ulcerative colitis (UC) and Crohn's disease (CD). PMID:27454774

  1. A convenient synthetic procedure yielding 2-picolinamino-N,N-diacetic acid monoamide derivatives, for labelling with the 'fac-[M(CO)3]+' core

    Recently, the introduction of the low valent fac-[M(CO)3(H2O)]+ synthons (M=Tc or Re) offered a new impetus in the development of diagnostic 99mTc(I) and therapeutic 186/188Re(I) radiopharmaceuticals. The aqua ligands of the fac-[M(CO)3(H2O)]+ cation are labile and readily substituted by a variety of functional groups including amines, thioethers, imines, thiols, and phosphines. Furthermore, the small size and the chemical inertness of the fac- [M(CO)3]+ core provide a convenient platform for the development of efficient radiopharmaceuticals. Previous studies on the coordination chemistry of the fac-[M(CO)3]+ core suggested that an ideal bifunctional chelating system should be tridentate because it forms complexes with more favourable pharmacokinetics compared to a bidentate one. Picollinamino N,N diacetic acid (PADA), 1, acts as tridentate NNO ligand and coordinates efficiently with the organometallic core at very low concentrations leaving a carboxylic group out of the coordination sphere of the metal. This carboxylic group can serve as an attachment site for functionalization with biologically active molecule rendering specificity to the overall complex. In this investigation we report a convenient, one-pot synthesis of a wide variety of monoamide derivatives of PADA, a simple method for tethering of a bioactive molecule that contains an amino group to the PADA ligand. The synthetic scheme includes the preparation of the anhydride of PADA, 2, and its subsequent reactions with the appropriate amines for the formation of the corresponding ligands, 3a-3c. Pyrrolidine and aniline were used as model compounds leading to the formation of ligands of 3a and 3b. Subsequently, 2-methoxyphenylpiperazine, which is a fragment of the true 5-HT1A antagonist WAY-100635 and displays affinity for the 5-HT1A receptors, reacted with the anhydride of PADA leading to the formation of 3c. These ligands were reacted successfully with the fac-M(CO)3 cores. The rhenium complexes 4a-c (M

  2. Preparation and Characteristics of Polyaluminium Chloride by Utilizing Fluorine-Containing Waste Acidic Mother Liquid from Clay-Brine Synthetic Cryolite Process

    2014-01-01

    Clay-brine process employing activated clay, NaCl, HCl, and HF as raw materials is the primarily advanced technology to synthesize cryolite in the present industrial grade. However, plenty of byproducts of fluorine-containing waste HCl at the concentration of about 10%~12% could not be utilized comprehensively and are even hazardous to the environment. This work proposed a new two-step technology to prepare inorganic polymer flocculants polyaluminium chloride (PAC) from synthetic cryolite mot...

  3. Preparation and Characteristics of Polyaluminium Chloride by Utilizing Fluorine-Containing Waste Acidic Mother Liquid from Clay-Brine Synthetic Cryolite Process

    Feng-shan Zhou

    2014-01-01

    Full Text Available Clay-brine process employing activated clay, NaCl, HCl, and HF as raw materials is the primarily advanced technology to synthesize cryolite in the present industrial grade. However, plenty of byproducts of fluorine-containing waste HCl at the concentration of about 10%~12% could not be utilized comprehensively and are even hazardous to the environment. This work proposed a new two-step technology to prepare inorganic polymer flocculants polyaluminium chloride (PAC from synthetic cryolite mother liquor. Many specific factors such as the variety of aluminide source, reaction temperature and time, reagent ratio, and manner of alkaline addition were taken into consideration and their influences on the performances of produced PAC were discussed. It was found that synthetic cryolite mother liquor could react with bauxite and calcium aluminate directly to prepare cheap PAC, with plenty amount of water insoluble CaF2 and CaSiF6 produced as well. However, once HCl was introduced into synthetic cryolite mother liquor as well as by utilizing bauxite as aluminide source and sodium aluminate as adjusting basicity agent, the resultant PAC would dissolve out higher amount of aluminum while producing little amount of water insoluble materials. The coagulation behavior of the specially produced PAC could even match the industrial grade PAC conforming to national standard.

  4. Contribution of carbohydrate and amino acids to the formation of aromatic structure of synthetic melanoidin (model sedimentary humic substance). A study using 13C-labeled glucose

    As a part of study to elucidate the source of aromatic structure in sedimentary humic substances (SHS), we synthesized melanoidins (a model SHS) from 13C-labeled glucose and non-labeled amino acids and examined how glucose and amino acids are involved in the formation of their aromatic structures. The synthesized melanoidin was oxidized by alkaline perman ganate and benzenecarboxylic acids in their degradation products were analyzed by Chemical Ionization-GC/MS. The results indicate that aromatic structures are formed in melanoidin as a result of both selfcondensation of glucose and a reaction between glucose and amino acids. (author)

  5. A contribution to the distinction of biogenic vinegar and vinegar made from synthetic acetic acid by determining the specific 14C-radioactivity

    The method of Simon et al. for the separation of the acetic acid from vinegar prior to the determination of the specific 14C-radioactivity has been modified. The precipitation as calcium acetate and the preparation of free acetic acid by addition of diphosphoric acid has been replaced by an extraction procedure with diisopropylether which is faster and cheaper. On the Austrian market glacial acetic acid (Merck, p.A.) having the natural specific 14C-radioactivity was found. The natural specific 14C-radioactivity is therefore necessary but not sufficient to prove the biogenic origin of vinegar. (orig.)

  6. Pictures of Synthetic Biology

    Cserer, Amelie; Seiringer, Alexandra

    2009-01-01

    This article is concerned with the representation of Synthetic Biology in the media and by biotechnology experts. An analysis was made of German-language media articles published between 2004 and 2008, and interviews with biotechnology-experts at the Synthetic Biology conference SB 3.0 in Zurich 2007. The results have been reflected in terms of the definition of Synthetic Biology, applications of Synthetic Biology and the perspectives of opportunities and risks. In the media, Synthetic Biolog...

  7. Where Synthetic Biology Meets ET

    Rothschild, Lynn J.

    2016-01-01

    Synthetic biology - the design and construction of new biological parts and systems and the redesign of existing ones for useful purposes - has the potential to transform fields from pharmaceuticals to fuels. Our lab has focused on the potential of synthetic biology to revolutionize all three major parts of astrobiology: Where do we come from? Where are we going? and Are we alone? For the first and third, synthetic biology is allowing us to answer whether the evolutionary narrative that has played out on planet earth is likely to have been unique or universal. For example, in our lab we are re-evolving the biosynthetic pathways of amino acids in order to understand potential capabilities of an early organism with a limited repertoire of amino acids and developing techniques for the recovery of metals from spent electronics on other planetary bodies. And what about the limits for life? Can we create organisms that expand the envelope for life? In the future synthetic biology will play an increasing role in human activities both on earth, in fields as diverse as human health and the industrial production of novel bio-composites. Beyond earth, we will rely increasingly on biologically-provided life support, as we have throughout our evolutionary history. In order to do this, the field will build on two of the great contributions of astrobiology: studies of the origin of life and life in extreme environments.

  8. Identification and Determination of Synthetic 10-Hydroxy-α-decanoic Acid in Adulterated Royal Jelly Products%蜂王浆制品中掺入人工癸烯酸的鉴别和测定

    刘秀红; 徐锦忠

    2016-01-01

    A new method to detect if synthetic 10-hydroxy-α-decanoic acid was added into pure royal jelly/lyophilized royal jelly was proposed. This method was conducted by comparing the HPLC/MS/MS spectrum of pure royal jelly/lyophilized royal jelly with those of adulterated samples in order to detect the differences between both sample groups. The maker was found to be presented in royal jelly/lyophilized royal jelly samples adulterated with synthetic 10-hydroxy-α-decanoic acid while could not be detected in any of pure royal jelly/lyophilized royal jelly samples analyzed. In addition, this method is a great innovation in detecting adulterated samples and the pre-processing approch is very simple. This method allowed the detection of synthetic 10-hydroxy-α-decanoic acid in adulterated royal jelly/lyophilized royal jelly samples in concentrations as low as 40μg/L.%采用高效液相色谱串联三重四级杆质谱为分析手段对蜂王浆/蜂王浆冻干粉中掺入的人工合成癸烯酸进行鉴别和测定。方法通过对比掺入人工合成癸烯酸标准品的阳性样品和天然蜂王浆的LC-MS/MS图谱的差别,发现了人工合成癸烯酸的特征离子峰,该特征离子峰在天然的蜂王浆和蜂王浆冻干粉中是不存在的,而是只存在于掺入了人工合成的癸烯酸的阳性样品中。此外,该方法在掺假食品检测领域具有创新性,前处理简单。该方法对于蜂王浆/蜂王浆冻干粉中掺入的人工合成癸烯酸的检测限可以达到40μg/L。

  9. Effect of low-molecular-weight carboxylic acids and selected synthetic chelates on zinc uptake and translocation in two wheat genotypes with different zinc-efficiency

    Sh. Haftbaradaran

    2013-10-01

    Full Text Available Zinc (Zn deficiency in human, which results from diets low in bioavailable zinc, could be eliminated by increasing readily plant-available Zn in soil. Root exudates and organic acids released during decomposition of soil organic matter can affect the availability of Zn. Thus, this hydroponic experiment was conducted to investigate the effect of some chelates on Zn uptake and translocation in two wheat genotypes with different zinc-efficiency. Two wheat genotypes (Triticum aestivum L. Back Cross Rowshan as zinc-efficient and Kavir as zinc-inefficient were exposed to two levels of zinc (10 and 100 µM and six different carboxylic acids (citric, tartaric, oxalic, salicylic, ethylenediamin tetraacetic acid and L-methionine. Results showed that uptake capability of free and complexed species of Zn were completely different. Zn2+ activity in nutrient solution had negative correlation with shoot dry weight and positive correlation with shoot zinc concentration in Kavir genotype, while complexed species had opposite results. Back Cross Rowshan genotype showed opposite results in comparison with Kavir genotype. The response of wheat genotypes to different organic acids varied. EDTA treatment caused the lowest shoot zinc concentration in Kavir genotype (18.8 mg/kg, while the Back Cross Rowshan genotype had highest concentration (99.5 mg/kg. Tartaric acid and citric acid caused the lowest root Zn concentration in the Kavir genotype (26.7 and 58.6 mg/kg, respectively, while the highest content was observed in the Back Cross Rowshan genotype (83.2 and 98.1 mg/kg, respectively. Catalase activity had inverse relationship with root Zn concentration in both genotypes. According to the results of this research, different responses of the wheat genotypes to organic acids are related to different mechanisms of zinc-efficiency in genotypes.

  10. OPEN QUESTIONS IN ORIGIN OF LIFE: EXPERIMENTAL STUDIES ON THE ORIGIN OF NUCLEIC ACIDS AND PROTEINS WITH SPECIFIC AND FUNCTIONAL SEQUENCES BY A CHEMICAL SYNTHETIC BIOLOGY APPROACH

    Katarzyna Adamala

    2014-02-01

    We have recently addressed these questions by using a chemical synthetic biology approach. In particular, we have tested the catalytic activity of small peptides, like Ser-His, with respect to peptide- and nucleotides-condensation, as a realistic model of primitive organocatalysis. We have also set up a strategy for exploring the sequence space of random proteins and RNAs (the so-called “never born biopolymer” project with respect to the production of folded structures. Being still far from solved, the main aspects of these “open questions” are discussed here, by commenting on recent results obtained in our groups and by providing a unifying view on the problem and possible solutions. In particular, we propose a general scenario for macromolecule formation via fragment-condensation, as a scheme for the emergence of specific sequences based on molecular growth and selection.

  11. Influence of "alternative" C-terminal amino acids on the formation of [b3 + 17 + Cat]+ products from metal cationized synthetic tetrapeptides.

    Anbalagan, V; Silva, A T M; Rajagopalachary, S; Bulleigh, K; Talaty, E R; Van Stipdonk, M J

    2004-05-01

    The aim of this study was to investigate the dissociation patterns, and in particular the relative abundance of [b(3) + 17 + Cat](+), for peptides with C-termini designed to allow transfer of the -OH required to generate the product ion, but not necessarily as the most favored pathway. Working with the hypothesis that formation of a five-membered ring intermediate, including intramolecular nucleophilic attack by a carbonyl oxygen atom, is an important mechanistic step, several model peptides with general sequence AcFGGX were synthesized, metal cationized by electrospray ionization and subjected to collision-induced dissociation (CID). The amino acid at position X was one that either required a larger ring intermediate (beta-alanine, gamma-aminobutyric acid and epsilon-amino-n-caproic acid to generate six-, seven- or nine- membered rings, respectively) to transfer -OH, lacked a structural element required for nucleophilic attack (aminoethanol) or prohibited cyclization because of the inclusion of a rigid ring (p- and m-aminobenzoic acid). For Ag(+), Li(+) and Na(+) cationized peptides, our results show that amino acids requiring the adoption of larger ring intermediates suppressed the formation of [b(3) + 17 + Cat](+), while amino acids that prohibit cyclization eliminated the reaction pathway completely. Formation of [b(3) - 1 + Cat](+) from the alkali metal cationized versions was not a favorable process upon suppression or elimination of the [b(3) + 17 + Cat](+) pathway: the loss of H(2)O to form [M - H(2)O + Cat](+) was instead the dominant dissociation reaction observed. Multiple-stage dissociation experiments suggest that [M - H(2)O + Cat](+) is not [b(4) - 1 + Cat](+) arising from the loss of H(2)O from the C-terminus, but may instead be a species that forms via a mechanism involving the elimination of an oxygen atom from an amide group. PMID:15170745

  12. Open questions in origin of life: experimental studies on the origin of nucleic acids and proteins with specific and functional sequences by a chemical synthetic biology approach

    Adamala, K.; Anella, F.; Wieczorek, R.;

    2014-01-01

    In this mini-review we present some experimental approaches to the important issue in the origin of life, namely the origin of nucleic acids and proteins with specific and functional sequences. The formation of macromolecules on prebiotic Earth faces practical and conceptual difficulties. From the...

  13. Establishing a synthetic pathway for high-level production of 3-hydroxypropionic acid in Saccharomyces cerevisiae via β-alanine

    Borodina, Irina; Kildegaard, Kanchana Rueksomtawin; Jensen, Niels Bjerg;

    2015-01-01

    Microbial fermentation of renewable feedstocks into plastic monomers can decrease our fossil dependence and reduce global CO2 emissions. 3-Hydroxypropionic acid (3HP) is a potential chemical building block for sustainable production of superabsorbent polymers and acrylic plastics. With the object...

  14. Coeliac disease: characterisation of monoclonal antibodies raised against a synthetic peptide corresponding to amino acid residues 206-217 of A-gliadin.

    Ellis, H. J.; Doyle, A. P.; Sturgess, R P; Ciclitira, P J

    1992-01-01

    A dodecapeptide of A-gliadin, which shares amino acid homologies with the E1b protein of adenovirus 12, was used to produce murine monoclonal antibodies. Five monoclonal antibodies were produced and were screened by enzyme linked immunosorbant assay, immunodot assay, and immunoblotting. The antibodies were tested against whole wheat gliadin and its alpha, beta, gamma, and omega subfractions, and the prolamins of rye, barley, oats, maize, millet, rice, and sorghum. Four of the five antibodies ...

  15. Selective dissolution of magnetic iron oxides in the acid-ammonium oxalate/ferrous iron extraction method-I. Synthetic samples

    Oorschot, I.H.M. van; Dekkers, M.J.

    2002-01-01

    In soil magnetism, the magnetic parameters alone are not always sufficient to distinguish the lithogenic from the pedogenic magnetic fractions. Sequential extraction techniques have therefore been incorporated into magnetic studies to constrain the environmental interpretation. Here we report on the dissolution behaviour of magnetite and maghemite in the acid-ammonium oxalate method to see whether the method is suitable for specific dissolution of magnetic minerals from soils and sediments. T...

  16. Polymeric nanoparticle of copper(II)-4,4′-dicyanamidobiphenyl ligand: Synthetic, spectral and structural aspect; application to electrochemical sensing of dopamine and ascorbic acid

    Graphical abstract: - Highlights: • The polymer [Cu(bp)(H2O)2]n synthesized and characterized. • The polymer was used as a modifier for the electrochemical determination of dopamine (DA) and ascorbic acid (AA). - Abstract: In this research, new polymer of 4,4′-dicyanamidobiphenyl (bpH2)-Cu(II) complex, [Cu(bp)(H2O)2]n, has been synthesized and characterized by FT-IR, UV–vis spectroscopy and elemental analysis. The spherical morphology of Cu nanoparticles was confirmed by scanning electron microscopy (SEM) image and the transmission electron microscopy (TEM) image showed that the particle size dimensions of Cu nanoparticles were about 80 nm. Thermal gravimetric analysis (TGA) results indicated that this polymer was thermally stable. Hence, the prepared polymer was used as a modifier for the electrochemical determination of dopamine (DA) and ascorbic acid (AA). Compared to the bare carbon paste electrode (CPE) and multiwall carbon paste electrode (CNTPE), bpCu modified CPE (bpCu-CPE) exhibits much higher electrocatalytic activities toward the oxidation of dopamine and ascorbic acid with an increase in peak currents and a decrease in oxidation overpotentials. The effects of scan rate, concentration and pH were also studied. Differential pulse voltammetry results show that DA and AA could be detected selectively and sensitively at bpCu-CPE with peak-to-peak separation of 200 mV. Relative standard deviations for AA and DA determinations were less than 2.5%, and the linear response ranges of the electrode were 0.05–30.0 μmol L−1 for AA and DA, respectively. The calculated detection limits were 0.02 and 0.04 μmol L−1 (S/N = 3) for AA and DA, respectively. In addition, the presented method was successfully applied for the simultaneous determination of DA and AA in urine and blood samples with reliable recovery

  17. Atorvastatin induces bile acid-synthetic enzyme Cyp7a1 by suppressing FXR signaling in both liver and intestine in mice[S

    Fu, Zidong Donna; Cui, Julia Yue; Klaassen, Curtis D.

    2014-01-01

    Statins are effective cholesterol-lowering drugs to treat CVDs. Bile acids (BAs), the end products of cholesterol metabolism in the liver, are important nutrient and energy regulators. The present study aims to investigate how statins affect BA homeostasis in the enterohepatic circulation. Male C57BL/6 mice were treated with atorvastatin (100 mg/kg/day po) for 1 week, followed by BA profiling by ultra-performance LC-MS/MS. Atorvastatin decreased BA pool size, mainly due to less BA in the inte...

  18. Synthetic approaches to multifunctional indenes

    López-Pérez, Sara; Dinarès, Immaculada

    2011-01-01

    Summary The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethyl)inden-5-yl)]amines, a reasonable pathway involves the (5-nitro-3-indenyl)acetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed immediately by dehydration with acid. This classical condensation process, which is neither simple nor trivial despite its apparent directness, permits an efficient entry to a variety of indene-based molecular modules, which could be adapted to a range of functionalized indanones. PMID:22238553

  19. Synthetic approaches to multifunctional indenes

    Neus Mesquida

    2011-12-01

    Full Text Available The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethylinden-5-yl]amines, a reasonable pathway involves the (5-nitro-3-indenylacetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed immediately by dehydration with acid. This classical condensation process, which is neither simple nor trivial despite its apparent directness, permits an efficient entry to a variety of indene-based molecular modules, which could be adapted to a range of functionalized indanones.

  20. Effect of different conditions and gamma irradiation on the dyeing affinity of natural and synthetic fabrics for cinnamic Acid derivative as a new application

    Cinnamic acid derivative; cinnamic acid,α-cyano-p dimethylamino-ethyl ester (CCDE) was used as a dye for different textile fabrics such as wool, nylon, polyester and wool/ polyester blend. The factors that may affect the dyeing process such as usual additives (carriers and dispersing agents), solvent, ph, dyeing temperature, dyeing time, CCDE concentration and irradiation dose were studied. The results of colour strength measurements indicate that irradiation prior to dyeing has no significant effect on the dye ability of nylon, polyester and wool/polyester blend. However, irradiation of wool fabrics prior to dyeing leads to slight improvement in the dye ability comared to the unirradiated fabric. Also, the dyeing affinity in the terms of colour strength was found to depend on the ph of the medium, in which the highest colour strength was achived at ph 4. Meanwhile, it was found that the solvents and usual dyeing additives have a significant effect on the dye ability. In this regard, the highest colour stringht was obtained by using benzyl alcohol (BA) and a carrier agent

  1. INTRACELLULAR ANTIOXIDANT ACTIVITY OF A STREPTOMYCES SP. 8812 SECONDARY METABOLITE, 6,7-DIHYDROXY-3,4-DIHYDROISOQINO- LINE-3-CARBOXYLIC ACID, AND ITS SYNTHETIC DERIVATIVES.

    Guśpiel, Adam; Ziemska, Joanna; Cześcik, Agnieszka; Kawecki, Robert; Solecka, Jolanta

    2016-01-01

    The aim of this study was to determine the antioxidant properties of 6,7-dihydroxy-3,4-dihydroiso- quinoline-3-carboxylic acid (1) and its derivatives in living cells against reactive forms of oxygen and nitrogen, i.e., hydrogen peroxide and nitric oxide. Four of tested compounds scavenged the reactive form of nitrogen more efficiently or similarly to Trolox (EC50 = 55.80 µM). Two compounds exhibited antioxidant activity against reactive oxygen species better than Trolox (EC50 = 51.88 µM). The most active derivative of 1 was the compound containing an iodine atom at position 8 (6,7-dihydroxy-8-iodo-3,4-dihydroisoquinoline-3-carboxylic acid). Our studies showed that some of the derivatives had the ability to cross the cell membrane and scavenge free radicals inside living cells. Thus, they are able to protect DNA and other cellular structures from the dam- aging effects of reactive oxygen and nitrogen species. In addition, some molecular descriptors of the tested compounds were determined with the use of ICM Pro (Molsoft L.L.C.). PMID:27476282

  2. Polymeric nanoparticle of copper(II)-4,4′-dicyanamidobiphenyl ligand: Synthetic, spectral and structural aspect; application to electrochemical sensing of dopamine and ascorbic acid

    Chiniforoshan, Hossein, E-mail: Chinif@cc.iut.ac.ir [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Ensafi, Ali A. [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Heydari-Bafrooei, Esmaeil [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, P.O. Box 518, Rafsanjan (Iran, Islamic Republic of); Khalesi, Sara Bahmanpour; Tabrizi, Leila [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2015-08-30

    Graphical abstract: - Highlights: • The polymer [Cu(bp)(H{sub 2}O){sub 2}]{sub n} synthesized and characterized. • The polymer was used as a modifier for the electrochemical determination of dopamine (DA) and ascorbic acid (AA). - Abstract: In this research, new polymer of 4,4′-dicyanamidobiphenyl (bpH{sub 2})-Cu(II) complex, [Cu(bp)(H{sub 2}O){sub 2}]{sub n}, has been synthesized and characterized by FT-IR, UV–vis spectroscopy and elemental analysis. The spherical morphology of Cu nanoparticles was confirmed by scanning electron microscopy (SEM) image and the transmission electron microscopy (TEM) image showed that the particle size dimensions of Cu nanoparticles were about 80 nm. Thermal gravimetric analysis (TGA) results indicated that this polymer was thermally stable. Hence, the prepared polymer was used as a modifier for the electrochemical determination of dopamine (DA) and ascorbic acid (AA). Compared to the bare carbon paste electrode (CPE) and multiwall carbon paste electrode (CNTPE), bpCu modified CPE (bpCu-CPE) exhibits much higher electrocatalytic activities toward the oxidation of dopamine and ascorbic acid with an increase in peak currents and a decrease in oxidation overpotentials. The effects of scan rate, concentration and pH were also studied. Differential pulse voltammetry results show that DA and AA could be detected selectively and sensitively at bpCu-CPE with peak-to-peak separation of 200 mV. Relative standard deviations for AA and DA determinations were less than 2.5%, and the linear response ranges of the electrode were 0.05–30.0 μmol L{sup −1} for AA and DA, respectively. The calculated detection limits were 0.02 and 0.04 μmol L{sup −1} (S/N = 3) for AA and DA, respectively. In addition, the presented method was successfully applied for the simultaneous determination of DA and AA in urine and blood samples with reliable recovery.

  3. Inhibitory effect of the carnosine-gallic acid synthetic peptide on MMP-2 and MMP-9 in human fibrosarcoma HT1080 cells.

    Kim, Sung-Rae; Eom, Tae-Kil; Byun, Hee-Guk

    2014-09-01

    Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade extracellular matrix components and play important roles in a variety of biological and pathological processes such as malignant tumor metastasis and invasion. In this study, we constructed carnosine-gallic acid peptide (CGP) to identify a better MMP inhibitor than carnosine. The inhibitory effects of CGP on MMP-2 and MMP-9 were investigated in the human fibrosarcoma (HT1080) cell line. As a result, CGP significantly decreased MMP-2 and MMP-9 expression levels without a cytotoxic effect. Moreover, CGP may inhibit migration and invasion in HT1080 cells through the urokinase plasminogen activator (uPA)-uPA receptor signaling pathways to inhibit MMP-2 and MMP-9. Based on these results, it appears that CGP may play an important role in preventing and treating several MMP-2 and MMP-9-mediated health problems such as metastasis. PMID:24956509

  4. Injectable hybrid hydrogels of hyaluronic Acid crosslinked by well-defined synthetic polycations: preparation and characterization in vitro and in vivo.

    Cross, Daisy; Jiang, Xiaoze; Ji, Weihang; Han, Wenqing; Wang, Chun

    2015-05-01

    An injectable hybrid hydrogel system was developed consisting of hyaluronic acid (HA) crosslinked by well-defined block copolymers of the cationic poly(2-aminoethyl methacrylate) (PAEM) and polyethylene glycol (PEG). Robust, shear-thinning hybrid hydrogel was produced by mixing HA and 4-arm star PEG-PAEM block copolymer at 1:1 charge ratio. The encapsulation and release of highly viable human mesenchymal stem cells in physiological media was demonstrated. After subcutaneous injection of the hybrid gel in mice, mild but resolvable inflammatory response was observed. This hybrid gel could serve as a model system for studying structure-function relationship of polyelectrolyte hydrogels and as a practical injectable biomaterial for medical applications. PMID:25630277

  5. Polymeric nanoparticle of copper(II)-4,4‧-dicyanamidobiphenyl ligand: Synthetic, spectral and structural aspect; application to electrochemical sensing of dopamine and ascorbic acid

    Chiniforoshan, Hossein; Ensafi, Ali A.; Heydari-Bafrooei, Esmaeil; Khalesi, Sara Bahmanpour; Tabrizi, Leila

    2015-08-01

    In this research, new polymer of 4,4‧-dicyanamidobiphenyl (bpH2)-Cu(II) complex, [Cu(bp)(H2O)2]n, has been synthesized and characterized by FT-IR, UV-vis spectroscopy and elemental analysis. The spherical morphology of Cu nanoparticles was confirmed by scanning electron microscopy (SEM) image and the transmission electron microscopy (TEM) image showed that the particle size dimensions of Cu nanoparticles were about 80 nm. Thermal gravimetric analysis (TGA) results indicated that this polymer was thermally stable. Hence, the prepared polymer was used as a modifier for the electrochemical determination of dopamine (DA) and ascorbic acid (AA). Compared to the bare carbon paste electrode (CPE) and multiwall carbon paste electrode (CNTPE), bpCu modified CPE (bpCu-CPE) exhibits much higher electrocatalytic activities toward the oxidation of dopamine and ascorbic acid with an increase in peak currents and a decrease in oxidation overpotentials. The effects of scan rate, concentration and pH were also studied. Differential pulse voltammetry results show that DA and AA could be detected selectively and sensitively at bpCu-CPE with peak-to-peak separation of 200 mV. Relative standard deviations for AA and DA determinations were less than 2.5%, and the linear response ranges of the electrode were 0.05-30.0 μmol L-1 for AA and DA, respectively. The calculated detection limits were 0.02 and 0.04 μmol L-1 (S/N = 3) for AA and DA, respectively. In addition, the presented method was successfully applied for the simultaneous determination of DA and AA in urine and blood samples with reliable recovery.

  6. Dissolution Kinetics of Synthetic and Natural Meta-Autunite Minerals, X3-n(n)+ [(UO2)(PO4)]2 · xH2O, Under Acidic Conditions

    Mass transport within the uranium geochemical cycle is impacted by the availability of phosphorus. In oxidizing environments, in which the uranyl ionic species is typically mobile, formation of sparingly soluble uranyl phosphate minerals exert a strong influence on uranium transport. Autunite group minerals have been identified as the long-term uranium controlling phases in many systems of geochemical interest. Anthropogenic operations related to uranium mining operations have created acidic environments, exposing uranyl phosphate minerals to low pH groundwater. Investigations regarding the dissolution behavior of autunite group minerals under acidic conditions have not been reported; consequently, knowledge of the longevity of uranium controlling solids is incomplete. The purpose of this investigation was to: (1) quantify the dissolution kinetics of natural calcium and synthetic sodium meta-autunite, under acidic conditions, (2) measure the effect of temperature and pH on meta-autunite mineral dissolution, and (3) investigate the formation of secondary uranyl phosphate phases as long-term controls on uranium migration. Single-pass flow-through (SPFT) dissolution tests were conducted over the pH range of 2 to 5 and from 5 to 70 C. Results presented here illustrate meta-autunite dissolution kinetics are strongly dependent on pH, but are relatively insensitive to temperature variations. In addition, the formation of secondary uranyl-phosphate phases such as, uranyl phosphate, (UO2)3(PO4)2 · x H2O, may serve as a secondary phase limiting the migration of uranium in the environment

  7. Test determination of aluminum, beryllium, and cationic surfactants using phenolcarboxylic acids of the triphenylmethane series immobilized on cloths from synthetic and natural fibers

    The use of cloth matrices from viscose and cotton fibers bearing phenolcarboxylic acids of the triphenylmethane series immobilized by adsorption in chemical test methods of analysis is considered. Chrome Azurol S, Sulfochrome, and Eriochrome Cyanine R were used for immobilization. It was found that the reagents are weakly retained on cellulose matrices. The degree of retention varied from 10 to 60%. It was observed that the reagent complexes of metal ions exhibited enhanced adsorbability on the matrices. Cloths with immobilized Chrome Azurol S were used in the test determination of 0.0005-0.5 mg/l beryllium and 0.0005-1.0 mg/l aluminum. When the reaction products were preconcentrated on the cloth from 100 ml of a test solution, the detection limit was 0.0001 mg/l. Procedures were developed for determining 0.1-100 mg/l aluminum and 0.02-0.6 mg/l beryllium in solutions using cloth test strips encapsulated into a polymeric film. It was demonstrated that Sulfochrome and Eriochrome Cyanine R immobilized on cloths can be used to determine 0.01-1 and 1-1000 mg/l cationic surfactants

  8. Variable Synthetic Capacitance

    Kleinberg, L. L.

    1986-01-01

    Feedback amplifier circuit synthesizes electronically variable capacitance. Variable Synthetic Capacitor is amplifier circuit with follower/feedback configuration. Effective input capacitance depends on input set current. If synthetic capacitor is connected across resonant element of oscillator, oscillator frequency controlled via input set current. Circuit especially suitable for fine frequency adjustments of piezoelectric-crystal or inductor/capacitor resonant oscillators.

  9. Synthetic Aperture Sequential Beamforming

    Kortbek, Jacob; Jensen, Jørgen Arendt; Gammelmark, Kim Løkke

    2008-01-01

    A synthetic aperture focusing (SAF) technique denoted Synthetic Aperture Sequential Beamforming (SASB) suitable for 2D and 3D imaging is presented. The technique differ from prior art of SAF in the sense that SAF is performed on pre-beamformed data contrary to channel data. The objective is to...

  10. Designing synthetic biology.

    Agapakis, Christina M

    2014-03-21

    Synthetic biology is frequently defined as the application of engineering design principles to biology. Such principles are intended to streamline the practice of biological engineering, to shorten the time required to design, build, and test synthetic gene networks. This streamlining of iterative design cycles can facilitate the future construction of biological systems for a range of applications in the production of fuels, foods, materials, and medicines. The promise of these potential applications as well as the emphasis on design has prompted critical reflection on synthetic biology from design theorists and practicing designers from many fields, who can bring valuable perspectives to the discipline. While interdisciplinary connections between biologists and engineers have built synthetic biology via the science and the technology of biology, interdisciplinary collaboration with artists, designers, and social theorists can provide insight on the connections between technology and society. Such collaborations can open up new avenues and new principles for research and design, as well as shed new light on the challenging context-dependence-both biological and social-that face living technologies at many scales. This review is inspired by the session titled "Design and Synthetic Biology: Connecting People and Technology" at Synthetic Biology 6.0 and covers a range of literature on design practice in synthetic biology and beyond. Critical engagement with how design is used to shape the discipline opens up new possibilities for how we might design the future of synthetic biology. PMID:24156739

  11. Eukaryotic Systems Broaden the Scope of Synthetic Biology

    Haynes, Karmella A.; Silver, Pamela A.

    2009-01-01

    Synthetic biology aims to engineer novel cellular functions by assembling well-characterized molecular parts (i.e., nucleic acids and proteins) into biological “devices” that exhibit predictable behavior. Recently, efforts in eukaryotic synthetic biology have sprung from foundational work in bacteria. Designing synthetic circuits to operate reliably in the context of differentiating and morphologically complex cells presents unique challenges and opportunities for progress in the field. This ...

  12. Application of the Organic Synthetic Designs to Astrobiology

    Kolb, V. M.

    2009-12-01

    In this paper we propose a synthesis of the heterocyclic compounds and the insoluble materials on the meteorites. Our synthetic scheme involves the reaction of sugars and amino acids, the so-called Maillard reaction. We have developed this scheme based on the combined analysis of the regular and retrosynthetic organic synthetic principles. The merits of these synthetic methods for the prebiotic design are addressed.

  13. Structural Aspects of Synthetic Ferrihydrite

    Michel, F. M.; Cismasu, C.; Tcaciuc, A. P.; Parise, J. B.; Brown, G. E.

    2008-12-01

    The role of natural ferrihydrite in geochemical and biological systems, and use of synthetic ferrihydrite in technological and industrial applications, is attracting broad scientific attention. The importance of ferrihydrite in these systems is primarily related to its large amount of reactive surface area (>350 m2 g-1) which has been shown to effectively scavenge a variety of potential contaminants (e.g., arsenic, chromium). In general, the association of ferrihydrite with metals and metalloids through sorption and co-precipitation is expected to alter its reactivity and thus affect its overall role in aqueous geochemical systems. Such changes in the reactivity of ferrihydrite nanoparticles, typically with all dimensions less than ~7 nm, are inextricably related to their atomic structure, i.e., the 3-dimensional arrangement of atoms. Evaluating the structures of particles with extreme small particle sizes (structure determination which are most sensitive to either short-range order (X-ray absorption spectroscopy) or long-range periodicity (X-ray or electron diffraction). However, the recent application of high-energy X-ray total scattering coupled with pair distribution function (PDF) analysis is providing new insight into the structural aspects of ferrihydrite, a material with no known crystalline counterpart. The information obtainable both directly and indirectly from the PDF will be discussed primarily using examples of synthetic inorganically-derived ferrihydrites. This work on synthetic samples complements our investigations of natural ferrihydrites forming in acid mine drainage-impacted waters. Such natural samples are inherently more complex because they typically form in the presence of dissolved inorganic species such as silica, aluminum, chromium, sulphate, etc., as well as organic matter. The complexity of natural ferrihydrites necessitates the use of synthetically-derived samples in order to evaluate specific changes in certain fundamental aspects of

  14. [Oral balanced synthetic diet (author's transl)].

    Hartig, W

    1976-01-01

    Oral balanced synthetic diet is a ballast-free, complete nutrition and is composed of chemical pure substances. It contains amino acids, mono- and oligosaccharids, essentiell fat acids, minerals, vitamines and tracer elements and is absorbed in jejunum. Oral balanced diet will be used with success to prepare diagnostic procedures and operations, for treatment of bowel-diseases, for patients with short-bowel-syndrom, with chronic hepatic diseases, metabolic diseases, maldigestion and malabsorption. PMID:827146

  15. Synthetic biological networks

    Despite their obvious relationship and overlap, the field of physics is blessed with many insightful laws, while such laws are sadly absent in biology. Here we aim to discuss how the rise of a more recent field known as synthetic biology may allow us to more directly test hypotheses regarding the possible design principles of natural biological networks and systems. In particular, this review focuses on synthetic gene regulatory networks engineered to perform specific functions or exhibit particular dynamic behaviors. Advances in synthetic biology may set the stage to uncover the relationship of potential biological principles to those developed in physics. (review article)

  16. Synthetic Cathinones ("Bath Salts")

    ... they are not increased sociability increased sex drive panic attacks excited delirium —extreme agitation and violent behavior What ... nosebleeds paranoia increased sociability increased sex drive hallucinations panic attacks Intoxication from synthetic cathinones has resulted in death. ...

  17. Synthetic biology and biosecurity.

    Robienski, Jürgen; Simon, Jürgen

    2014-01-01

    This article discusses the conflict fields and legal questions of synthetic biology, esp. concerning biosecurity. A respective jurisprudential discussion has not taken place yet in Germany apart from few statements and recommendations. But in Germany, Europe and the USA, it is generally accepted that a broad discussion is necessary. This is esp. true for the question of biosecurity and the possible dangers arising from Synthetic Biology. PMID:25845204

  18. Building synthetic memory

    Inniss, Mara C.; Silver, Pamela A.

    2013-01-01

    Cellular memory – conversion of a transient signal into a sustained response – is a common feature of biological systems. Synthetic biologists aim to understand and reengineer such systems in a reliable and predictable manner. Synthetic memory circuits have been designed and built in vitro and in vivo based on diverse mechanisms such as oligonucleotide hybridization, recombination, transcription, phosphorylation, and RNA editing. Thus far, building these circuits has helped us explore the bas...

  19. Synthetic Vision Systems

    Prinzel, L.J.; Kramer, L.J.

    2009-01-01

    A synthetic vision system is an aircraft cockpit display technology that presents the visual environment external to the aircraft using computer-generated imagery in a manner analogous to how it would appear to the pilot if forward visibility were not restricted. The purpose of this chapter is to review the state of synthetic vision systems, and discuss selected human factors issues that should be considered when designing such displays.

  20. Soap, Fatty Acids, and Synthetic Detergents

    Chupa, Janine; Misner, Steve; Sachdev, Amit; Smith, George A.

    The origin of the word "soap" is traced to sacrificial Mount Sapo of ancient Roman legend. The mixture of fat and wood ashes that reacted to form soap was carried by rain to the banks of the Tiber River and was found as a clay deposit useful for cleaning clothes.1

  1. Synthetic gauge fields in synthetic dimensions,

    Celi, A; Massignan, P.; Ruseckas, J.; Goldman, N; Spielman, I. B.; Juzeliūnas, G.; Lewenstein, M.

    2013-01-01

    We describe a simple technique for generating a cold-atom lattice pierced by a uniform magnetic field. Our method is to extend a one-dimensional optical lattice into the "dimension" provided by the internal atomic degrees of freedom, yielding a synthetic 2D lattice. Suitable laser-coupling between these internal states leads to a uniform magnetic flux within the 2D lattice. We show that this setup reproduces the main features of magnetic lattice systems, such as the fractal Hofstadter butterf...

  2. Oxygen Pressure Acid Leaching Synthetic Reclaiming of Complex Cu -Pb Bulk Concentrate%复杂铜铅混合精矿氧压浸出综合回收工艺

    杨俊奎; 徐斌; 杨大锦; 钟宏; 姜涛

    2011-01-01

    The main copper and lead minerals in complex Cu - Pb bulk concentrate from Sichuan province of China are tetrahedrite and galena, and there are also abundant Pb, Zn, Fe, As and Sb in the concentrate. The concentrate is treated by oxygen pressure acid leaching synthetic reclaiming technique. The best technology conditions are obtained by experiments. It is concluded through the enlarged experiment that the leaching rates of copper and zinc are 98.89% and 94.92% respectively, and that the elements of Pb and Ag transform into sulfate and sulfid depositions. The abruption between Cu, Zn and Pb, Ag is complete. Copper and Zinc are reclaimed with the method of extraction and electrolyse. While lead and silver in the leaching residue are reclaimed through the translation of carbonate first, and then leaching Pb with silicofluoric acid and leaching Ag with thiourea at the last. The extraction rate of copper, leaching rate of lead and silver are 96%, 94% and 93% respectively.%呷村铜铅混合精矿中铜、铅矿物主要为黝铜矿和方铅矿,还含有较高的锌、银、砷和锑.本试验针对该矿采用一段氧压浸出综合回收工艺进行处理,通过条件优化实验确定了氧压浸出的操作条件.扩大验证实验表明Cu、Zn的浸出率分别高达98.89%、94.92%,Pb、Ag转化为矾类和硫化物形式留在浸出渣中,铜锌与铅银分离彻底.浸出液中的铜、锌分别通过萃取、电积进行回收.浸出渣中的铅、银通过碳酸盐转化-硅氟酸浸铅-硫脲浸银进行回收.铜萃取率,铅、银浸出率分别为96%、94%和93%.

  3. Automated synthetic scene generation

    Givens, Ryan N.

    Physics-based simulations generate synthetic imagery to help organizations anticipate system performance of proposed remote sensing systems. However, manually constructing synthetic scenes which are sophisticated enough to capture the complexity of real-world sites can take days to months depending on the size of the site and desired fidelity of the scene. This research, sponsored by the Air Force Research Laboratory's Sensors Directorate, successfully developed an automated approach to fuse high-resolution RGB imagery, lidar data, and hyperspectral imagery and then extract the necessary scene components. The method greatly reduces the time and money required to generate realistic synthetic scenes and developed new approaches to improve material identification using information from all three of the input datasets.

  4. Towards developing algal synthetic biology.

    Scaife, Mark Aden; Smith, Alison Gail

    2016-06-15

    The genetic, physiological and metabolic diversity of microalgae has driven fundamental research into photosynthesis, flagella structure and function, and eukaryotic evolution. Within the last 10 years these organisms have also been investigated as potential biotechnology platforms, for example to produce high value compounds such as long chain polyunsaturated fatty acids, pigments and antioxidants, and for biodiesel precursors, in particular triacylglycerols (TAGs). Transformation protocols, molecular tools and genome sequences are available for a number of model species including the green alga Chlamydomonas reinhardtii and the diatom Phaeodactylum tricornutum, although for both species there are bottlenecks to be overcome to allow rapid and predictable genetic manipulation. One approach to do this would be to apply the principles of synthetic biology to microalgae, namely the cycle of Design-Build-Test, which requires more robust, predictable and high throughput methods. In this mini-review we highlight recent progress in the areas of improving transgene expression, genome editing, identification and design of standard genetic elements (parts), and the use of microfluidics to increase throughput. We suggest that combining these approaches will provide the means to establish algal synthetic biology, and that application of standard parts and workflows will avoid parallel development and capitalize on lessons learned from other systems. PMID:27284033

  5. Synthetic guide star generation

    Payne, Stephen A [Castro Valley, CA; Page, Ralph H [Castro Valley, CA; Ebbers, Christopher A [Livermore, CA; Beach, Raymond J [Livermore, CA

    2008-06-10

    A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

  6. Poly (lactide-co-glycolide) acid nanoencapsulation of a synthetic coumarin: Cytotoxicity and bio-distribution in mice, in cancer cell line and interaction with calf thymus DNA as target

    Several naturally occurring coumarin compounds, including scopoletin (7 hydroxy-6 methoxycoumarin), of plant origin have been reported to have anti-cancer potentials. A related but chemically synthesized coumarin, 4-methyl-7-hydroxy coumarin (SC), was also shown to have similar anti-cancer potentials. In the present study, to test if nano-encapsulated SC could be a more potent anti-cancer agent, we encapsulated SC with poly lactide-co-glycolide acid (PLGA) nanoparticles (Nano Coumarin; NC) and tested its potentials with a variety of protocols. NC demonstrated greater efficiency of drug uptake and showed anti-cancer potentials in melanoma cell line A375, as revealed from scanning electronic and atomic force microscopies. To test its possible interaction with target DNA, the combined data of circular dichroism spectra (CD) and melting temperature profile (Tm) of calf thymus DNA treated with NC were analyzed. Results indicated a concentration dependent interaction of NC with calf thymus DNA, bringing in effective change in structure and conformation, and forming a new complex that increased its stability. Particle size and morphology of NC determined through polydispersity index and zeta potential using dynamic light scattering qualified NC to be a more potent anti-cancer agent than SC. Further, SC and NC showed negligible cytotoxic effects on normal skin cells and peripheral blood mononuclear cells of mice. Distribution assay of PLGA nanoparticles in different tissues like brain, heart, kidneys, liver, lungs, and spleen in mice revealed the presence of nanoparticles in different tissues including brain, indicating that the particles could cross the blood brain barrier, significant information for drug design. - Graphical abstract: Nanoencapsulated coumarin (NC) were characterized for their size and morphology by scanning electron (SEM) and atomic force microscopies (AFM).The physical interaction of the NC with calf thymus DNA was studied through circular dichroism

  7. Microorganism Utilization for Synthetic Milk

    Morford, Megan A.; Khodadad, Christina L.; Caro, Janicce I.; Spencer, LaShelle E.; Richards, Jeffery T.; Strayer, Richard F.; Birmele, Michele N.; Wheeler, Raymond M.

    2014-01-01

    A desired architecture for long duration spaceflight, like aboard the International Space Station or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of the Synthetic Biology project, Cow in a Column, was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel-through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) in order to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products. For future work, the production of the casein protein for milk would require the development of a genetically modified organism, which was beyond the scope of the original project. Additional trials would be needed to further refine the required

  8. Synthetic Aperture Radar Interferometry

    Rosen, P. A.; Hensley, S.; Joughin, I. R.; Li, F.; Madsen, S. N.; Rodriguez, E.; Goldstein, R. M.

    1998-01-01

    Synthetic aperture radar interferometry is an imaging technique for measuring the topography of a surface, its changes over time, and other changes in the detailed characteristics of the surface. This paper reviews the techniques of interferometry, systems and limitations, and applications in a rapidly growing area of science and engineering.

  9. Synthetic River Valleys

    Brown, R.; Pasternack, G. B.

    2011-12-01

    The description of fluvial form has evolved from anecdotal descriptions to artistic renderings to 2D plots of cross section or longitudinal profiles and more recently 3D digital models. Synthetic river valleys, artificial 3D topographic models of river topography, have a plethora of potential applications in fluvial geomorphology, and the earth sciences in general, as well as in computer science and ecology. Synthetic river channels have existed implicitly since approximately the 1970s and can be simulated from a variety of approaches spanning the artistic and numerical. An objective method of synthesizing 3D stream topography based on reach scale attributes would be valuable for sizing 3D flumes in the physical and numerical realms, as initial input topography for morphodynamic models, stream restoration design, historical reconstruction, and mechanistic testing of interactions of channel geometric elements. Quite simply - simulation of synthetic channel geometry of prescribed conditions can allow systematic evaluation of the dominant relationships between river flow and geometry. A new model, the control curve method, is presented that uses hierarchically scaled parametric curves in over-lapping 2D planes to create synthetic river valleys. The approach is able to simulate 3D stream geometry from paired 2D descriptions and can allow experimental insight into form-process relationships in addition to visualizing past measurements of channel form that are limited to two dimension descriptions. Results are presented that illustrate the models ability to simulate fluvial topography representative of real world rivers as well as how channel geometric elements can be adjusted. The testing of synthetic river valleys would open up a wealth of knowledge as to why some 3D attributes of river channels are more prevalent than others as well as bridging the gap between the 2D descriptions that have dominated fluvial geomorphology the past century and modern, more complete, 3D

  10. Synthetic and natural antioxidants: food quality protectors

    Valenzuela, A.; Nieto, S.

    1996-01-01

    Oxidation of food lipid components, known as oxidative rancidity is one of the major deteriorative and quality-affecting reactions. Oxidative rancidity is initiated by oxygen free-radicals or by the reaction of molecular oxygen with pre-formed organic free-radicals from polyunsaturated fatty acids composing fats and oils. Oxidation may be prevented or delayed by antioxidants, these substances being organic molecules of either synthetic or natural origin which can scavenge the oxygen free-radi...

  11. Synthetic Genomics and Synthetic Biology Applications Between Hopes and Concerns

    König, Harald; Frank, Daniel; Heil, Reinhard; Coenen, Christopher

    2013-01-01

    New organisms and biological systems designed to satisfy human needs are among the aims of synthetic genomics and synthetic biology. Synthetic biology seeks to model and construct biological components, functions and organisms that do not exist in nature or to redesign existing biological systems to perform new functions. Synthetic genomics, on the other hand, encompasses technologies for the generation of chemically-synthesized whole genomes or larger parts of genomes, allowing to simultaneo...

  12. Wholly Synthetic Molecular Machines.

    Cheng, Chuyang; Stoddart, J Fraser

    2016-06-17

    The past quarter of a century has witnessed an increasing engagement on the part of physicists and chemists in the design and synthesis of molecular machines de novo. This minireview traces the development of artificial molecular machines from their prototypes in the form of shuttles and switches to their emergence as motors and pumps where supplies of energy in the form of chemical fuel, electrochemical potential and light activation become a minimum requirement for them to function away from equilibrium. The challenge facing this rapidly growing community of scientists and engineers today is one of putting wholly synthetic molecules to work, both individually and as collections. Here, we highlight some of the recent conceptual and practical advances relating to the operation of wholly synthetic rotary and linear motors. PMID:26833859

  13. Synthetic Fuels Program

    Studies on waste water derived from synthetic fuel processes included acute toxicity of coal conversion effluent components and acute toxicity of aqueous waste and wastewater components of the ORNL Bench-Scale hydrocarbonization process. The potential hazards of synthetic fuels technology development to terrestrial ecosystems were studied with regard to toxicity of PAH and azaarenes. Aquatic transport studies included the following: aquatic transport of PAH and rates of PAH photolysis at the Bethlehem, Pennsylvania, coking plant site; microbial transformations of polycyclic aromatic hydrocarbons in water and sediment samples; persistence of azaarenes in aquatic systems; bioaccumulation of pathways of azaarenes; sorption of PAH to suspended particles in natural waters; and transport and fate of anthracene in pond microcosms. Studies were also conducted on environmental characterization of solid waste from a Lurgi facility

  14. Engineered Asymmetric Synthetic Vesicles

    Lu, Li; Chiarot, Paul

    2013-11-01

    Synthetic vesicles are small, fluid-filled spheres that are enclosed by a bilayer of lipid molecules. They can be used as models for investigating membrane biology and as delivery vehicles for pharmaceuticals. In practice, it is difficult to simultaneously control membrane asymmetry, unilamellarity, vesicle size, vesicle-to-vesicle uniformity, and luminal content. Membrane asymmetry, where each leaflet of the bilayer is composed of different lipids, is of particular importance as it is a feature of most natural membranes. In this study, we leverage microfluidic technology to build asymmetric vesicles at high-throughput. We use the precise flow control offered by microfluidic devices to make highly uniform emulsions, with controlled internal content, that serve as templates to build the synthetic vesicles. Flow focusing, dielectrophoretic steering, and interfacial lipid self-assembly are critical procedures performed on-chip to produce the vesicles. Fluorescent and confocal microscopy are used to evaluate the vesicle characteristics.

  15. Role of Synthetic and Dimensional Synthetic Organic Chemistry in Block Copolymer Micelle Nanosensor Engineering

    Ek, Pramod Kumar

    This thesis investigated the role of amphiphilic triblock copolymer micelle nanomaterials in nanosensors, with emphasis on the synthesis of micelle particle sensors. The thesis is focused on the role of synthetic and dimensional synthetic organic chemistry in amphiphilic triblock core...... micelles. Shell cross-linking on PEG-b-PAEMA-b-PS micelles was performed by amidation reactions between the amino groups of PAEMA blocks using a di-carboxylic acid cross-linker. Also a dendritic cross-linker based click chemistry was used to stabilize the PEG-b-PAEMA-b-PES micelle having click readied PES...

  16. These Synthetic Times

    KIT GILLET

    2008-01-01

    @@ Already slated to be one of the most important cultural events in the buildup to this summer's Olympic games, Synthetic Times-Media Art China 2008 will feature the works of more than 30 artists from around the world. Upwards of 40 media art installations will be exhibited in the National Art Museum of China alone, along with performances, workshops, presentations, and discussion panels focusing on the art works and the growth of media art as a discipline.

  17. Interaction of actinide cations with synthetic polyelectrolytes

    The binding of Am+3, Th+4 and UO2+2 to polymaleic acid, polyethylenemaleic acid and polymethylvinylethermaleic acid has been measured by a solvent extraction technique at 250C and either 0.02 or 0.10 M ionic strength. The solutions were buffered over a pH range such that the percent of carboxylate groups ionized ranged from 25 to 74%. The binding was described by two constants, β1 and β2, which were evaluated after correction for complexation of the actinide cations by acetate and hydrolysis. For comparable degrees of ionization, all three polyelectrolytes showed similar binding strengths. In general, these results indicated that the binding of actinides to these synthetic polyelectrolytes is basically similar to that of natural polyelectrolytes such as humic and fulvic acids. (orig.)

  18. Synthetic staggered architecture composites

    Highlights: ► Composite design inspired by nature. ► Tuning microstructure via changing ceramic content and aspect ratio. ► Experimental display of structure–property correlationship in synthetic composites. - Abstract: Structural biocomposites (for example, nacre in seashells, bone, etc.) are designed according to the functional role they are delegated for. For instance, bone is primarily designed for withstanding time-dependent loading (for example, withstanding stresses while running, jumping, accidental fall) and hence the microstructure is designed primarily from enhanced toughness and moderate stiffness point of view. On the contrary, seashells (which lie in the abyss of oceans) apart from providing defense to the organism (it is hosting) against predatory attacks, are subjected to static loading (for example, enormous hydrostatic pressure). Hence, emphasis on the shell structure evolution is directed primarily towards providing enhanced stiffness. In order to conform between stiffness and toughness, nature precisely employs a staggered arrangement of inorganic bricks in a biopolymer matrix (at its most elementary level of architecture). Aspect ratio and content of ceramic bricks are meticulously used by nature to synthesize composites having varying degrees of stiffness, strength and toughness. Such an amazing capability of structure–property correlationship has rarely been demonstrated in synthetic composites. Therefore, in order to better understand the mechanical behavior of synthetic staggered composites, the problem becomes two-pronged: (a) synthesize composites with varying brick size and contents and (b) experimental investigation of the material response. In this article, an attempt has been made to synthesize and characterize staggered ceramic–polymer composites having varying aspect ratio and ceramic content using freeze-casting technique. This will in-turn help us in custom-design manufacture of hybrid bio-inspired composite materials

  19. CASH vs. SYNTHETIC CDOs

    Silviu Eduard Dinca

    2016-01-01

    Full Text Available During the past few years, in the recent post-crisis aftermath, global asset managers are constantly searching new ways to optimize their investment portfolios while financial and banking institutions around the world are exploring new alternatives to better secure their financing and refinancing demands altogether with the enhancement of their risk management capabilities. We will exhibit herewith a comparison between the true-sale and synthetic CDO securitizations as financial markets-based funding, investment and risks mitigation techniques, highlighting certain key structuring and implementation specifics on each of them.

  20. Synthetic Aperture Compound Imaging

    Hansen, Jens Munk

    Medical ultrasound imaging is used for many purposes, e.g. for localizing and classifying cysts, lesions, and other processes. Almost any mass is first observed using B-mode imaging and later classified using e.g. color flow, strain, or attenuation imaging. It is therefore important that the B...... and the limiting factor is the amount of memory IO resources available. An equally high demand for memory throughput is found in the computer gaming industry, where a large part of the processing takes place on the graphics processing unit (GPU). Using the GPU, a framework for synthetic aperture imaging...

  1. Transition in synthetic jets

    Tesař, Václav; Kordík, Jozef

    Roč. 187, NOV 2012 ( 2012 ), s. 105-117. ISSN 0924-4247 R&D Projects: GA TA ČR(CZ) TA02020795; GA ČR(CZ) GPP101/12/P556; GA ČR(CZ) GCP101/11/J019 Institutional research plan: CEZ:AV0Z20760514 Keywords : turbulence * synthetic jet * transition * velocity spectra Subject RIV: BK - Fluid Dynamics Impact factor: 1.841, year: 2012 http://www.sciencedirect.com/science/article/pii/S0924424712005031

  2. Analog synthetic biology.

    Sarpeshkar, R

    2014-03-28

    We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations. PMID:24567476

  3. Synthetic biology: Understanding biological design from synthetic circuits

    Mukherji, Shankar; van Oudenaarden, Alexander

    2009-01-01

    An important aim of synthetic biology is to uncover the design principles of natural biological systems through the rational design of gene and protein circuits. Here, we highlight how the process of engineering biological systems — from synthetic promoters to the control of cell–cell interactions — has contributed to our understanding of how endogenous systems are put together and function. Synthetic biological devices allow us to grasp intuitively the ranges of behaviour generated by simple...

  4. An allosteric synthetic DNA.

    Wu, L.; Curran, J F

    1999-01-01

    Allosteric DNA oligonucleotides are potentially useful diagnostic reagents. Here we develop a model system for the study of allosteric interactions in DNAs. A DNA that binds either Cibacron blue or cholic acid was isolated and partially characterized. Isolation was performed using a multi-stage SELEX. First, short oligos that bind either Cibacron blue or cholic acid were enriched from random oligonucleotide pools. Then, members of the two pools were fused to form longer oligos, which were the...

  5. Tissue Harmonic Synthetic Aperture Imaging

    Rasmussen, Joachim

    The main purpose of this PhD project is to develop an ultrasonic method for tissue harmonic synthetic aperture imaging. The motivation is to advance the field of synthetic aperture imaging in ultrasound, which has shown great potentials in the clinic. Suggestions for synthetic aperture tissue...... harmonic techniques have been made, but none of these methods have so far been applicable for in-vivo imaging. The basis of this project is a synthetic aperture technique known as synthetic aperture sequential beamforming (SASB). The technique utilizes a two step beamforming approach to drastically reduce...... system complexity compared to conventional synthetic aperture techniques. In this project, SASB is sought combined with a pulse inversion technique for 2nd harmonic tissue harmonic imaging. The advantages in tissue harmonic imaging (THI) are expected to further improve the image quality of SASB. The...

  6. Synthetic Biology for Therapeutic Applications

    Abil, Zhanar; Xiong, Xiong; Zhao, Huimin

    2014-01-01

    Synthetic biology is a relatively new field with the key aim of designing and constructing biological systems with novel functionalities. Today, synthetic biology devices are making their first steps in contributing new solutions to a number of biomedical challenges, such as emerging bacterial antibiotic resistance and cancer therapy. This review discusses some synthetic biology approaches and applications that were recently used in disease mechanism investigation and disease modeling, drug d...

  7. Synthetic circuits, devices and modules

    Zhang, Hong; Jiang, Taijiao

    2010-01-01

    The aim of synthetic biology is to design artificial biological systems for novel applications. From an engineering perspective, construction of biological systems of defined functionality in a hierarchical way is fundamental to this emerging field. Here, we highlight some current advances on design of several basic building blocks in synthetic biology including the artificial gene control elements, synthetic circuits and their assemblies into devices and modules. Such engineered basic buildi...

  8. Synthetic antibiofilm peptides.

    de la Fuente-Núñez, César; Cardoso, Marlon Henrique; de Souza Cândido, Elizabete; Franco, Octavio Luiz; Hancock, Robert E W

    2016-05-01

    Bacteria predominantly exist as multicellular aggregates known as biofilms that are associated with at least two thirds of all infections and exhibit increased adaptive resistance to conventional antibiotic therapies. Therefore, biofilms are major contributors to the global health problem of antibiotic resistance, and novel approaches to counter them are urgently needed. Small molecules of the innate immune system called host defense peptides (HDPs) have emerged as promising templates for the design of potent, broad-spectrum antibiofilm agents. Here, we review recent developments in the new field of synthetic antibiofilm peptides, including mechanistic insights, synergistic interactions with available antibiotics, and their potential as novel antimicrobials against persistent infections caused by biofilms. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert. PMID:26724202

  9. Variation and Synthetic Speech

    Miller, C; Massey, N; Miller, Corey; Karaali, Orhan; Massey, Noel

    1997-01-01

    We describe the approach to linguistic variation taken by the Motorola speech synthesizer. A pan-dialectal pronunciation dictionary is described, which serves as the training data for a neural network based letter-to-sound converter. Subsequent to dictionary retrieval or letter-to-sound generation, pronunciations are submitted a neural network based postlexical module. The postlexical module has been trained on aligned dictionary pronunciations and hand-labeled narrow phonetic transcriptions. This architecture permits the learning of individual postlexical variation, and can be retrained for each speaker whose voice is being modeled for synthesis. Learning variation in this way can result in greater naturalness for the synthetic speech that is produced by the system.

  10. Synthetic Aperture Ultrasound Imaging

    Jensen, Jørgen Arendt; Nikolov, Svetoslav; Gammelmark, Kim Løkke;

    2006-01-01

    The paper describes the use of synthetic aperture (SA) imaging in medical ultrasound. SA imaging is a radical break with today's commercial systems, where the image is acquired sequentially one image line at a time. This puts a strict limit on the frame rate and the possibility of acquiring a...... SA imaging. Due to the complete data set, it is possible to have both dynamic transmit and receive focusing to improve contrast and resolution. It is also possible to improve penetration depth by employing codes during ultrasound transmission. Data sets for vector flow imaging can be acquired using...... short imaging sequences, whereby both the correct velocity magnitude and angle can be estimated. A number of examples of both phantom and in-vivo SA images will be presented measured by the experimental ultrasound scanner RASMUS to demonstrate the many benefits of SA imaging....

  11. Fluorescence spectroscopy of synthetic melanin in solution

    Perna, G.; Frassanito, M.C. [Dipartimento di Scienze Biomediche, Universita di Foggia, Viale Pinto, 71100 Foggia (Italy); Palazzo, G. [Dipartimento di Chimica, Universita di Bari, Via Orabona 4, 70126 Bari (Italy); Gallone, A. [Dipartimento di Scienze Biomediche, Universita di Foggia, Viale Pinto, 71100 Foggia (Italy); Mallardi, A. [ICPS-CNR, Via Orabona 4, 70126 Bari (Italy); Biagi, P.F. [Dipartimento Interateneo di Fisica, Universita di Bari, Via Amendola 173, 70126 Bari (Italy); Capozzi, V. [Dipartimento di Scienze Biomediche, Universita di Foggia, Viale Pinto, 71100 Foggia (Italy)], E-mail: v.capozzi@unifg.it

    2009-01-15

    We report a detailed investigation of fluorescence properties of synthetic eumelanin pigment in solution. A complete set of fluorescence spectra in the near-UV and visible range is analysed. Excitation spectra at a few selected emission energies are also investigated. Our measurements support the hypothesis that fluorescence in eumelanin is related to chemically distinct oligomeric units that can be selectively excited. Fluorescence due to large oligomer systems is spectrally differentiated from that due to monomers and small oligomer systems. Fluorescence excitation measurements show the contribution of 5,6-dihydroxyndole-2-carboxylic acid and 5,6-dihydroxyndole monomers to the emission of small-size oligomers.

  12. Life after the synthetic cell

    Rasmussen, Steen

    2010-01-01

    Nature asked eight synthetic-biology experts about the implications for science and society of the “synthetic cell” made by the J. Craig Venter Institute (JCVI). The institute's team assembled, modified and implanted a synthesized genome into a DNA-free bacterial shell to make a self-replicating ...

  13. Sequential Beamforming Synthetic Aperture Imaging

    Kortbek, Jacob; Jensen, Jørgen Arendt; Gammelmark, Kim Løkke

    2013-01-01

    Synthetic aperture sequential beamforming (SASB) is a novel technique which allows to implement synthetic aperture beamforming on a system with a restricted complexity, and without storing RF-data. The objective is to improve lateral resolution and obtain a more depth independent resolution...

  14. Interferometric synthetic aperture microscopy

    Ralston, Tyler S.; Marks, Daniel L.; Scott Carney, P.; Boppart, Stephen A.

    2007-02-01

    State-of-the-art methods in high-resolution three-dimensional optical microscopy require that the focus be scanned through the entire region of interest. However, an analysis of the physics of the light-sample interaction reveals that the Fourier-space coverage is independent of depth. Here we show that, by solving the inverse scattering problem for interference microscopy, computed reconstruction yields volumes with a resolution in all planes that is equivalent to the resolution achieved only at the focal plane for conventional high-resolution microscopy. In short, the entire illuminated volume has spatially invariant resolution, thus eliminating the compromise between resolution and depth of field. We describe and demonstrate a novel computational image-formation technique called interferometric synthetic aperture microscopy (ISAM). ISAM has the potential to broadly impact real-time three-dimensional microscopy and analysis in the fields of cell and tumour biology, as well as in clinical diagnosis where in vivo imaging is preferable to biopsy.

  15. Synthetic plasma ion source

    An improved crossed-beam charge-exchange ion gun in which a synthetic plasma is formed by injecting an electron beam into a collimated molecular beam just before the molecules are ionized by charge exchange with a crossed primary ion beam, thereby forming a secondary ion beam from the ionized but space-charge-neutralized and substantially undeflected molecular beam. The plasma thus formed extends to an aperture stop in an aperture tube which extends upstream from an anode downstream of which anode a cathode is placed. A field is formed within the cathode/anode space and within the aperture tube into which the plasma extends. The sheath edge of the plasma within the tube is curved by the field to form a meniscus, and the aperture, being smaller in area than the secondary ion beam upstream of the aperture, both collimates the secondary ion beam and acts as a lens stop for the subsequent immersion lens formed by the meniscus and the field region

  16. Computing with synthetic protocells.

    Courbet, Alexis; Molina, Franck; Amar, Patrick

    2015-09-01

    In this article we present a new kind of computing device that uses biochemical reactions networks as building blocks to implement logic gates. The architecture of a computing machine relies on these generic and composable building blocks, computation units, that can be used in multiple instances to perform complex boolean functions. Standard logical operations are implemented by biochemical networks, encapsulated and insulated within synthetic vesicles called protocells. These protocells are capable of exchanging energy and information with each other through transmembrane electron transfer. In the paradigm of computation we propose, protoputing, a machine can solve only one problem and therefore has to be built specifically. Thus, the programming phase in the standard computing paradigm is represented in our approach by the set of assembly instructions (specific attachments) that directs the wiring of the protocells that constitute the machine itself. To demonstrate the computing power of protocellular machines, we apply it to solve a NP-complete problem, known to be very demanding in computing power, the 3-SAT problem. We show how to program the assembly of a machine that can verify the satisfiability of a given boolean formula. Then we show how to use the massive parallelism of these machines to verify in less than 20 min all the valuations of the input variables and output a fluorescent signal when the formula is satisfiable or no signal at all otherwise. PMID:25969126

  17. Synthetic Genetic Array Analysis.

    Kuzmin, Elena; Costanzo, Michael; Andrews, Brenda; Boone, Charles

    2016-01-01

    Genetic interaction studies have been used to characterize unknown genes, assign membership in pathway and complex, and build a comprehensive functional map of a eukaryotic cell. Synthetic genetic array (SGA) methodology automates yeast genetic analysis and enables systematic mapping of genetic interactions. In its simplest form, SGA consists of a series of replica pinning steps that enable construction of haploid double mutants through automated mating and meiotic recombination. Using this method, a strain carrying a query mutation, such as a deletion allele of a nonessential gene or a conditional temperature-sensitive allele of an essential gene, can be crossed to an input array of yeast mutants, such as the complete set of approximately 5000 viable deletion mutants. The resulting output array of double mutants can be scored for genetic interactions based on estimates of cellular fitness derived from colony-size measurements. The SGA score method can be used to analyze large-scale data sets, whereas small-scale data sets can be analyzed using SGAtools, a simple web-based interface that includes all the necessary analysis steps for quantifying genetic interactions. PMID:27037072

  18. Secondary structure of fluorescence labelled synthetic peptides

    Martin, A S

    2000-01-01

    A series of eight synthetic oligopeptides has been prepared and their secondary structures investigated using various techniques. The project represents a continuation of an investigation into thermally induced changes in secondary structure. Following the previously reported results, the change in structure was initially thought to represent a change from an alpha-helix at low temperature to 3 sub 1 sub 0 -helix at high temperature. However, the results reported herein suggest the peptides retain an alpha-helical configuration at all temperatures studied, but that this helix can adopt at least two related forms. The difference in the structures relates to the nature of the H-bonds which may or may not involve an additional interaction from water molecules or side-chains. The peptides were encouraged to adopt a helical configuration by the inclusion of alpha- aminoisobutyric acid (Aib) residues. Also, modified forms of glutamic acid were included in the sequences. These had pendant donor (4-methoxy naphthalen...

  19. Adsorption of polar aromatic hydrocarbons on synthetic calcite

    Madsen, Lene; Grahl-Madsen, Laila; Grøn, Christian; Lind, Ida; Engell, John

    1996-01-01

    The wettability of hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. A model system of synthetic call cite, cyclohexane and the three probe molecules: benzoic acid, benzyl alcohol and benzylamine, have been...

  20. Synthetic biology: advancing biological frontiers by building synthetic systems

    Chen, Yvonne Yu-Hsuan; Galloway, Kate E.; Smolke, Christina D.

    2012-01-01

    Advances in synthetic biology are contributing to diverse research areas, from basic biology to biomanufacturing and disease therapy. We discuss the theoretical foundation, applications, and potential of this emerging field.

  1. A Course on Synthetic Fuels.

    Kimmel, Howard S.; Tomkins, Reginald P. T.

    1985-01-01

    A senior-level, elective course on synthetic fuels was developed for chemistry and chemical engineering majors. The topics covered in this course, instructional strategies used, and independent student projects are described. (JN)

  2. Synthetic Aperture Radar - Hardware Development

    Rosner, V.; Seller, R.; L. Dudas; Kazi, K.; Miko, G.

    2009-01-01

    Experimental real and synthetic aperture radar are developed from the base-band digital unit to the analogue RF parts, based on solid state units, using pulse compression for radar imaging. Proper QPSK code is found for matched filter.

  3. Compounding in synthetic aperture imaging.

    Hansen, Jens Munk; Jensen, Jørgen Arendt

    2012-09-01

    A method for obtaining compound images using synthetic aperture data is investigated using a convex array transducer. The new approach allows spatial compounding to be performed for any number of angles without reducing the frame rate or temporal resolution. This important feature is an intrinsic property of how the compound images are constructed using synthetic aperture data and an improvement compared with how spatial compounding is obtained using conventional methods. The synthetic aperture compound images are created by exploiting the linearity of delay-and-sum beamformation for data collected from multiple spherical emissions to synthesize multiple transmit and receive apertures, corresponding to imaging the tissue from multiple directions. The many images are added incoherently, to produce a single compound image. Using a 192-element, 3.5-MHz, λ-pitch transducer, it is demonstrated from tissue-phantom measurements that the speckle is reduced and the contrast resolution improved when applying synthetic aperture compound imaging. At a depth of 4 cm, the size of the synthesized apertures is optimized for lesion detection based on the speckle information density. This is a performance measure for tissue contrast resolution which quantifies the tradeoff between resolution loss and speckle reduction. The speckle information density is improved by 25% when comparing synthetic aperture compounding to a similar setup for compounding using dynamic receive focusing. The cystic resolution and clutter levels are measured using a wire phantom setup and compared with conventional application of the array, as well as to synthetic aperture imaging without compounding. If the full aperture is used for synthetic aperture compounding, the cystic resolution is improved by 41% compared with conventional imaging, and is at least as good as what can be obtained using synthetic aperture imaging without compounding. PMID:23007781

  4. Synthetic Life: Our Hybrid Future

    Rickus, Jenna

    2014-01-01

    Several fields of science and engineering, including synthetic biology, neuroengineering, computer science, and nanotechnology, are working toward the creation of new forms of and modifications to life. This session will explore what we can do now to create synthetic life, what has already been done, and what we might do in the future. The session will include a discussion on possible frameworks for how science and society can responsibly move forward together.

  5. Synthetic Biology: Integrated Gene Circuits

    Nandagopal, Nagarajan; Michael B Elowitz

    2011-01-01

    A major goal of synthetic biology is to develop a deeper understanding of biological design principles from the bottom up, by building circuits and studying their behavior in cells. Investigators initially sought to design circuits “from scratch” that functioned as independently as possible from the underlying cellular system. More recently, researchers have begun to develop a new generation of synthetic circuits that integrate more closely with endogenous cellular processes. These approaches...

  6. SYNTHETIC SLING FAILURE - EVALUATIONS & RECOMMENDATIONS

    MACKEY TC; HENDERSON CS

    2009-10-26

    The information and evaluations provided in this report were compiled to address the recurring problem of synthetic sling failure. As safety is the number one priority in all work aspects, a solution must be devised to prevent accidents from occurring. A total of thirteen cases regarding synthetic sling failure were evaluated in order to determine their causes, effects, and preventative measures. From the collected data, it was found that all cases in which the synthetic sling contacted the edge of its load resulted in sling failure. It is required that adequate synthetic sling protection devices be used to protect slings in any lift where the sling comes in direct contact with the edge or corner of its load. However, there are no consensus codes or standards stating the type, material, or purpose of the type of protective device used to protect the sling from being cut. Numerous industry standards and codes provide vague descriptions on how to protect synthetic slings. Without a clear, concise statement of how to protect synthetic slings, it is common for inadequate materials and sling protection devices to be used in an attempt to meet the intent of these requirements. The use of an inadequate sling protection device is the main cause of synthetic sling failure in all researched cases. Commercial sling protection devices come in many shapes and sizes, and have a variety of names, as well as advertised uses. 'Abrasion pads' and 'wear protectors' are two different names for products with the same intended purpose. There is no distinguishable way to determine the extent of sling protection which these devices will provide, or what specific scenarios they are made for. This creates room for error in a field where error is unacceptable. This report provides a recommended action for hoisting and rigging activities which require synthetic slings to contact a load, as well as recommended changes to industry standards which will benefit overall

  7. Synthetic aperture controlled source electromagnetics

    Fan, Y.; Snieder, R.; Slob, E.; Hunziker, J.W.; Singer, J.; Sheiman, J.; Rosenquist, M.

    2010-01-01

    Controlled‐source electromagnetics (CSEM) has been used as a de‐risking tool in the hydrocarbon exploration industry. Although there have been successful applications of CSEM, this technique is still not widely used in the industry because the limited types of hydrocarbon reservoirs CSEM can detect. In this paper, we apply the concept of synthetic aperture to CSEM data. Synthetic aperture allows us to design sources with specific radiation patterns for different purposes. The ability to detec...

  8. The muscle protein synthetic response to food ingestion.

    Gorissen, Stefan H M; Rémond, Didier; van Loon, Luc J C

    2015-11-01

    Preservation of skeletal muscle mass is of great importance for maintaining both metabolic health and functional capacity. Muscle mass maintenance is regulated by the balance between muscle protein breakdown and synthesis rates. Both muscle protein breakdown and synthesis rates have been shown to be highly responsive to physical activity and food intake. Food intake, and protein ingestion in particular, directly stimulates muscle protein synthesis rates. The postprandial muscle protein synthetic response to feeding is regulated on a number of levels, including dietary protein digestion and amino acid absorption, splanchnic amino acid retention, postprandial insulin release, skeletal muscle tissue perfusion, amino acid uptake by muscle, and intramyocellular signaling. The postprandial muscle protein synthetic response to feeding is blunted in many conditions characterized by skeletal muscle loss, such as aging and muscle disuse. Therefore, it is important to define food characteristics that modulate postprandial muscle protein synthesis. Previous work has shown that the muscle protein synthetic response to feeding can be modulated by changing the amount of protein ingested, the source of dietary protein, as well as the timing of protein consumption. Most of this work has studied the postprandial response to the ingestion of isolated protein sources. Only few studies have investigated the postprandial muscle protein synthetic response to the ingestion of protein dense foods, such as dairy and meat. The current review will focus on the capacity of proteins and protein dense food products to stimulate postprandial muscle protein synthesis and identifies food characteristics that may modulate the anabolic properties. PMID:26021783

  9. Boronic acid-based autoligation of nucleic acids

    Barbeyron, R.; Vasseur, J.-J.; Smietana, M.;

    2013-01-01

    Abstract: The development of synthetic systems displaying dynamic and adaptive characteristics is a formidable challenge with wide applications from biotechnology to therapeutics. Recently, we described a dynamic and programmable nucleic acid-based system relying on the formation of reversible...

  10. Synthetic biology for microbial production of lipid-based biofuels.

    d'Espaux, Leo; Mendez-Perez, Daniel; Li, Rachel; Keasling, Jay D

    2015-12-01

    The risks of maintaining current CO2 emission trends have led to interest in producing biofuels using engineered microbes. Microbial biofuels reduce emissions because CO2 produced by fuel combustion is offset by CO2 captured by growing biomass, which is later used as feedstock for biofuel fermentation. Hydrocarbons found in petroleum fuels share striking similarity with biological lipids. Here we review synthetic metabolic pathways based on fatty acid and isoprenoid metabolism to produce alkanes and other molecules suitable as biofuels. We further discuss engineering strategies to optimize engineered biosynthetic routes, as well as the potential of synthetic biology for sustainable manufacturing. PMID:26479184

  11. Synthetic Photochemistry. LIII. Low-Temperature Irradiation of Methyl 2,4-Dioxopentanoate with alpha-Phellandrene, p-Mentha-1,5-diene. Product Distribution and Further Occurrence of "retro-Benzilic Acid Rearrengement"

    Hatsui, Toshihide; Nojima, Chitoshi; Takeshita, Hitoshi

    1989-01-01

    Low-temperature irradiation of methyl 2,4-dioxopentanoate with p-mentha-1,5-diene (alpha-phellandrene) gave retro-benzilic acid rearrangement products in low but reproducible yields, after a pyrolytic workup, together with isomeric [4+2] cycloadducts. This indicates an accumulation of the proto-photocycloadducts during the reaction. The product analysis indicated the [2+2] and [4+2] cycloadditions are mutually independent processes.

  12. Meeting Report: Synthetic Biology Jamboree for Undergraduates

    Campbell, A. Malcolm

    2005-01-01

    The field of synthetic biology (the name is derived from an analogy to synthetic chemistry) has recognized itself as a "field" only since about 2002. Synthetic biology has gotten some high-profile attention recently, but most people are not aware the field even exists. Synthetic biologists apply engineering principles to genomic circuits to…

  13. Content metamorphosis in synthetic holography

    A synthetic hologram is an optical system made of hundreds of images amalgamated in a structure of holographic cells. Each of these images represents a point of view on a three-dimensional space which makes us consider synthetic holography as a multiple points of view perspective system. In the composition of a computer graphics scene for a synthetic hologram, the field of view of the holographic image can be divided into several viewing zones. We can attribute these divisions to any object or image feature independently and operate different transformations on image content. In computer generated holography, we tend to consider content variations as a continuous animation much like a short movie. However, by composing sequential variations of image features in relation with spatial divisions, we can build new narrative forms distinct from linear cinematographic narration. When observers move freely and change their viewing positions, they travel from one field of view division to another. In synthetic holography, metamorphoses of image content are within the observer's path. In all imaging Medias, the transformation of image features in synchronisation with the observer's position is a rare occurrence. However, this is a predominant characteristic of synthetic holography. This paper describes some of my experimental works in the development of metamorphic holographic images.

  14. Synthetic Peptide Immunogens Elicit Polyclonal and Monoclonal Antibodies Specific for Linear Epitopes in the D Motifs of Staphylococcus aureus Fibronectin-Binding Protein, Which Are Composed of Amino Acids That Are Essential for Fibronectin Binding

    Huesca, Mario; Sun, Qing; Peralta, Robert; Shivji, Gulnar M.; Sauder, Daniel N.; McGavin, Martin J.

    2000-01-01

    A fibronectin (Fn)-binding adhesin of Staphylococcus aureus contains three tandem 37- or 38-amino-acid motifs (D1, D2, and D3), which function to bind Fn. Plasma from patients with S. aureus infections contain antibodies that preferentially recognize ligand induced binding sites in the D motifs and do not inhibit Fn binding (F. Casolini, L. Visai, D. Joh, P. G. Conaldi, A. Toniolo, M. Höök, and P. Speziale, Infect. Immun. 66:5433–5442, 1998). To eliminate the influence of Fn binding on antibo...

  15. Designer Drugs: A Synthetic Catastrophe

    James Fratantonio

    2015-08-01

    Full Text Available Synthetic stimulants can cause hallucinations, aggressive behaviors, death and are sometimes legal. These substances are sold as plant food and bath salts that are "Not for Human Consumption", therefore skirting the 1986 Federal Analogue Act and giving a false pretense of safety. Studies have proved that these substances are toxic, have a high abuse potential, and are becoming extremely prevalent in the United States. This creates a dilemma for law enforcement agents, hospitals, and substance use disorder treatment centers. Urine Drug Testing is utilized as a clinical diagnostic tool in substance use disorder treatment centers, and the furious pace at which new synthetic stimulants are introduced to the black market are making the detection via urine increasingly difficult. This article will discuss the prevalence, pharmacology and difficulty developing laboratory assays to detect synthetic stimulants.

  16. Microfluidic Technologies for Synthetic Biology

    Sung Kuk Lee

    2011-06-01

    Full Text Available Microfluidic technologies have shown powerful abilities for reducing cost, time, and labor, and at the same time, for increasing accuracy, throughput, and performance in the analysis of biological and biochemical samples compared with the conventional, macroscale instruments. Synthetic biology is an emerging field of biology and has drawn much attraction due to its potential to create novel, functional biological parts and systems for special purposes. Since it is believed that the development of synthetic biology can be accelerated through the use of microfluidic technology, in this review work we focus our discussion on the latest microfluidic technologies that can provide unprecedented means in synthetic biology for dynamic profiling of gene expression/regulation with high resolution, highly sensitive on-chip and off-chip detection of metabolites, and whole-cell analysis.

  17. Synthetic neurosteroids on brain protection

    Mariana Rey; Hctor Coirini

    2015-01-01

    Neurosteroids, like allopregnanolone and pregnanolone, are endogenous regulators of neuronal excitability. Inside the brain, they are highly selective and potent modulators of GABAA receptor activity. Their anticonvulsant, anesthetics and anxiolytic properties are useful for the treatments of several neurological and psychiatric disordersvia reducing the risks of side effects obtained with the commercial drugs. The principal disadvantages of endogenous neurosteroids adminis-tration are their rapid metabolism and their low oral bioavailability. Synthetic steroids analogues with major stability or endogenous neurosteroids stimulation synthesis might constitute prom-ising novel strategies for the treatment of several disorders. Numerous studies indicate that the 3α-hydroxyl conifguration is the key for binding and activity, but modiifcations in the steroid nucleus may emphasize different pharmacophores. So far, several synthetic steroids have been developed with successful neurosteroid-like effects. In this work, we summarize the properties of various synthetic steroids probed in trials throughout the analysis of several neurosteroids-like actions.

  18. US Competitiveness in Synthetic Biology.

    Gronvall, Gigi Kwik

    2015-01-01

    Synthetic biology is an emerging technical field that aims to make biology easier to engineer; the field has applications in strategically important sectors for the US economy. While the United States currently leads in synthetic biology R&D, other nations are heavily investing in order to boost their economies, which will inevitably diminish the US leadership position. This outcome is not entirely negative--additional investments will expand markets--but it is critical that the US government take steps to remain competitive: There are applications from which the US population and economy may benefit; there are specific applications with importance for national defense; and US technical leadership will ensure that US experts have a leading role in synthetic biology governance, regulation, and oversight. Measures to increase competitiveness in S&T generally are broadly applicable for synthetic biology and should be pursued. However, the US government will also need to take action on fundamental issues that will affect the field's development, such as countering anti-GMO (genetically modified organism) sentiments and anti-GMO legislation. The United States should maintain its regulatory approach so that it is the product that is regulated, not the method used to create a product. At the same time, the United States needs to ensure that the regulatory framework is updated so that synthetic biology products do not fall into regulatory gaps. Finally, the United States needs to pay close attention to how synthetic biology applications may be governed internationally, such as through the Nagoya Protocol of the Convention on Biological Diversity, so that beneficial applications may be realized. PMID:26690379

  19. The Case for Synthetic Injectables.

    Joseph, John H

    2015-11-01

    There are several different classes of synthetic dermal fillers and volume enhancers including semipermanent and permanent products available in the United States. Based on clinical and scientific evidence, this article reviews the chemical and polymeric properties, clinical data, patient selection, indications for use, injection technique, and adverse event profiles of permanent synthetic injectables currently used in clinical practice in the United States: medical-grade liquid injectable silicone and polymethyl methacrylate. Understanding the unique characteristics of these two products reinforces the advantages and disadvantages of each, including under what circumstances they should be used and why they perform the way they do. PMID:26505540

  20. SYNTHETIC APPROACHES TO POLIFUNCTIONALIZED PERHYDRINDANES

    Veaceslav Kulciţki

    2011-12-01

    Full Text Available The current communication represents an extended abstract of the presentation delivered on the joint Moldo-Italian seminar “New frontiers in natural product chemistry”, held in the Institute of Chemistry, Academy of Sciences of Moldova on 31 September. An overview of the synthetic methods oriented to the synthesis of functionalized terpenic perhydrindanes is provided. Different synthetic strategies are considered, including those based on biomimetic approach. The array of obtained new structures can serve as leads in structure-activity studies as well as useful building blocks towards other perhydrindanes.

  1. Synthetic technology of castor oleic acid Trimethylolpropane ester%蓖麻油酸三羟甲基丙烷酯的合成工艺条件及性能

    焦体; 胡文云; 唐志辉; 周诗磊; 邹晨

    2012-01-01

    以蓖麻油和三羟甲基丙烷为原料,通过皂化,酯化合成蓖麻油酸三羟酯,研究了原料配比,催化剂用量,反应温度,反应时间等对酯化反应的影响,最佳条件为:蓖麻油与三羟甲基丙烷的摩尔比为5∶4,,催化剂用量为蓖麻油酸质量的0.5%,反应温度180 ~ 200℃,反应时间4h.生成的蓖麻油酸三羟甲基丙烷酯为黄色透明液体,产率为86.48%,用红外光谱进行了定性分析,证明了目标产物的存在,采用了热重/差热综合热分析仪研究了其热稳定性,采用了运动粘度测定仪研究了其粘温性能.结果表明:其润滑性能、热稳定性、粘温性能满足工艺润滑油基础油的要求.%With castor oil and Trimethylolpropane as raw material, castor oleic acid ester was synthesized by the saponification and esterification. The ratio of raw material, catalyst dosage, reaction temperature and reaction time on the esterification of influence was studied. And the best conditions were as follows; castor oil and Trimethylolpropane mole ratio of 5: 4, catalyst dosage of the mass of oleic acid castor for 0. 5 % , reaction temperature 180-200 °C , reaction time 4 h. The Castor oleic acid Trimethylolpropane ester is a kind of yellow transparent liquid, production rate is 86.48%. It is proved the existence of the target product with infrared spectra of qualitative analysis. The results show that; the lubrication properties, thermal stability, glue temperature performance meet the technological requirements of base oil lubricating oil.

  2. Synthetic and natural antioxidants: food quality protectors

    Valenzuela, A.

    1996-06-01

    Full Text Available Oxidation of food lipid components, known as oxidative rancidity is one of the major deteriorative and quality-affecting reactions. Oxidative rancidity is initiated by oxygen free-radicals or by the reaction of molecular oxygen with pre-formed organic free-radicals from polyunsaturated fatty acids composing fats and oils. Oxidation may be prevented or delayed by antioxidants, these substances being organic molecules of either synthetic or natural origin which can scavenge the oxygen free-radicals involved in fatty acid oxidation. Synthetic antioxidants are the most popular and widely used antioxidants, however concerns about it safe to both human and animal health is encouraging research on substances from natural origin showing antioxidant properties. Few natural antioxidants have been proved to be effective when compared to synthetic products in the same experimental conditions. This work summarizes the main characteristics of the most important synthetic antioxidants, also discuss the principal characteristics of four natural antioxidants, comparing the advantages and disadvantages of using natural products compared to synthetic ones, and sight the future for natural products with antioxidant activity.

    La oxidación de los componentes lípidos de un alimento, conocida como rancidez oxidativa, es una de las reacciones que deteriora y afecta en forma más importante la calidad de un producto. La rancidez oxidativa es iniciada por radicales libres del oxígeno o por el ataque del oxígeno molecular a radicales libres pre-formados en los ácidos grasos poliinsaturados que forman las grasas y aceites. La oxidación puede ser prevenida o retrasada por los antioxidantes, sustancias orgánicas de origen sintético o natural que actúan como atrapadores de los radicales libres del oxígeno involucrados en la oxidación de los ácidos grasos. Los antioxidantes sintéticos son los más populares y ampliamente utilizados, sin embargo existe

  3. Analysis of the Synthetic Jet

    Dančová, Petra; Vít, Tomáš

    2009-01-01

    Roč. 2, č. 1 (2009), s. 11-17. ISSN 1803-0203 R&D Projects: GA AV ČR(CZ) IAA200760801 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jet * actuator * nominal frequency Subject RIV: BJ - Thermodynamics

  4. Synthetic Aperture Radar - Hardware Development

    V. Rosner

    2009-06-01

    Full Text Available Experimental real and synthetic aperture radar are developed from the base-band digital unit to the analogue RF parts, based on solid state units, using pulse compression for radar imaging. Proper QPSK code is found for matched filter.

  5. Spatial cognition in synthetic environments

    Meijer, Frank

    2011-01-01

    The current dissertation discussed the use of Virtual Reality in product design, referred to as the use of Synthetic Environments (SEs). The research of two basic and two case studies focused on investigating the effectiveness of SEs for the users. We expected that the users’ insight in the possibil

  6. Shock compression of synthetic opal

    Inoue, A.; Okuno, M.; Okudera, H.; Mashimo, T.; Omurzak, E.; Katayama, S.; Koyano, M.

    2010-03-01

    Structural change of synthetic opal by shock-wave compression up to 38.1 GPa has been investigated by using SEM, X-ray diffraction method (XRD), Infrared (IR) and Raman spectroscopies. Obtained information may indicate that the dehydration and polymerization of surface silanole due to high shock and residual temperature are very important factors in the structural evolution of synthetic opal by shock compression. Synthetic opal loses opalescence by 10.9 and 18.4 GPa of shock pressures. At 18.4 GPa, dehydration and polymerization of surface silanole and transformation of network structure may occur simultaneously. The 4-membered ring of TO4 tetrahedrons in as synthetic opal may be relaxed to larger ring such as 6-membered ring by high residual temperature. Therefore, the residual temperature may be significantly high at even 18.4 GPa of shock compression. At 23.9 GPa, opal sample recovered the opalescence. Origin of this opalescence may be its layer structure by shock compression. Finally, sample fuse by very high residual temperature at 38.1 GPa and the structure closes to that of fused SiO2 glass. However, internal silanole groups still remain even at 38.1 GPa.

  7. New Synthetic Method of Ciprofloxacin

    2001-01-01

    A new synthetic method of ciprofloxacin is started with 2,4-dichloro-5-fluoroacetophenone, via oxaly lation, ethoxymethylenation, amination, cyclization, hydrolysis, decarbonylation and piperazination. The reaction temperature is moderate and the operation is easily controlled. Additional four new compounds are prepared by the method.

  8. New Synthetic Method of Ciprofloxacin

    陈英奇; 戴立言

    2001-01-01

    A new synthetic method of ciprofloxacin is started with 2,4-dichloro-5-fluoroacetophenone, via oxaly-lation, ethoxymethylenation, amination, cyclization, hydrolysis, decarbonylation and piperazination. The reaction temperature is moderate and the operation is easily controlled. Additional four new compounds are prepared by the method.

  9. Protease-sensitive synthetic prions.

    David W Colby

    2010-01-01

    Full Text Available Prions arise when the cellular prion protein (PrP(C undergoes a self-propagating conformational change; the resulting infectious conformer is designated PrP(Sc. Frequently, PrP(Sc is protease-resistant but protease-sensitive (s prions have been isolated in humans and other animals. We report here that protease-sensitive, synthetic prions were generated in vitro during polymerization of recombinant (rec PrP into amyloid fibers. In 22 independent experiments, recPrP amyloid preparations, but not recPrP monomers or oligomers, transmitted disease to transgenic mice (n = 164, denoted Tg9949 mice, that overexpress N-terminally truncated PrP. Tg9949 control mice (n = 174 did not spontaneously generate prions although they were prone to late-onset spontaneous neurological dysfunction. When synthetic prion isolates from infected Tg9949 mice were serially transmitted in the same line of mice, they exhibited sPrP(Sc and caused neurodegeneration. Interestingly, these protease-sensitive prions did not shorten the life span of Tg9949 mice despite causing extensive neurodegeneration. We inoculated three synthetic prion isolates into Tg4053 mice that overexpress full-length PrP; Tg4053 mice are not prone to developing spontaneous neurological dysfunction. The synthetic prion isolates caused disease in 600-750 days in Tg4053 mice, which exhibited sPrP(Sc. These novel synthetic prions demonstrate that conformational changes in wild-type PrP can produce mouse prions composed exclusively of sPrP(Sc.

  10. Injertos sustitutos no óseos: Aportaciones del ácido poliláctico y poliglicólico Synthetic grafts materials: Polylactide and poliglycolide acid effects in bone regeneration

    M. Marín Ruiz

    2009-04-01

    Full Text Available En el presente trabajo se realiza una revisión bibliográfica de los sustitutos no óseos disponibles en el mercado para mejorar y acelerar la regeneración ósea centrándonos en los polímeros de ácido poliláctico y poliglicólico por su relativa novedad para dicha aplicación. Los resultados obtenidos permiten confirmar la capacidad osteoconductora de dichos sustitutos en los procesos reparativos óseos pero a menudo también pueden actuar como barrera del proceso fisiológico de autorremodelación ósea al requerir un tiempo de reabsorción demasiado largo.The goal of the present study is to describe the nonbony sustitutes available to improve and to acelerate the bone regeneration pointing us polilactide and poliglycolide acid polymers by its relative newness for this application. The results confirm the osteoconductive capacity of this sustitutes in the bone regeneration even thought they can also be a barrier on the osseous autoremodelation of the physiological process as they need long time to be reabsorbed.

  11. Improvement of a synthetic lure for Anopheles gambiae using compounds produced by human skin microbiota

    Verhulst, N.O.; Mbadi, P.A.; Bukovinszkine-Kiss, G.; Mukabana, W.R.; Loon, van J.J.A.; Takken, W.; Smallegange, R.C.

    2011-01-01

    Background - Anopheles gambiae sensu stricto is considered to be highly anthropophilic and volatiles of human origin provide essential cues during its host-seeking behaviour. A synthetic blend of three human-derived volatiles, ammonia, lactic acid and tetradecanoic acid, attracts A. gambiae. In addi

  12. Synthetic peptides and ribosomal proteins as substrate for 60S ribosomal protein kinase from yeast cells

    Grankowski, N; Gasior, E; Issinger, O G

    1993-01-01

    Kinetic studies on the 60S protein kinase were conducted with synthetic peptides and ribosomal proteins as substrate. Peptide RRREEESDDD proved to be the best synthetic substrate for this enzyme. The peptide has a sequence of amino acids which most closely resembles the structure of potential...... phosphorylation sites in natural substrates, i.e., acidic ribosomal proteins. The superiority of certain kinetic parameters for 60S kinase obtained with the native whole 80S ribosomes over those of the isolated fraction of acidic ribosomal proteins indicates that the affinity of 60S kinase to the specific protein...

  13. An electrokinetic study of synthetic greigite and pyrrhotite

    Dekkers, M.J.; Schoonen, M.A.A.

    1994-01-01

    The isoefectric points of synthetic greigite, Fe&, and pyrrhotite, Fe, _& in 10 -3- 1.1 10 -* M NaCl solution at or, < lop4 and as < 10W4 were determined to be pH 3 and 2, respectively. Below pH 2 for pyrrhotite and below pH 3 for greigite, the surfaces are positively charged; above these pH values the surfaces are negatively charged. Upon addition of sulfidic sulfur (H$, HS-), traces of terrestrial humic acids, or a combination of sulfidic sulfur and terrestrial humic acids, the surfaces are...

  14. Synthetic Metal-Containing Polymers

    Manners, Ian

    2004-04-01

    The development of the field of synthetic metal-containing polymers - where metal atoms form an integral part of the main chain or side group structure of a polymer - aims to create new materials which combine the processability of organic polymers with the physical or chemical characteristics associated with the metallic element or complex. This book covers the major developments in the synthesis, properties, and applications of synthetic metal-containing macromolecules, and includes chapters on the preparation and characterization of metal-containing polymers, metallocene-based polymers, rigid-rod organometallic polymers, coordination polymers, polymers containing main group metals, and also covers dendritic and supramolecular systems. The book describes both polymeric materials with metals in the main chain or side group structure and covers the literature up to the end of 2002.

  15. Compounding in synthetic aperture imaging

    Hansen, J. M.; Jensen, J. A.

    2012-01-01

    A method for obtaining compound images using synthetic aperture data is investigated using a convex array transducer. The new approach allows spatial compounding to be performed for any number of angles without reducing the frame rate or temporal resolution. This important feature is an intrinsic...... from multiple spherical emissions to synthesize multiple transmit and receive apertures, corresponding to imaging the tissue from multiple directions. The many images are added incoherently, to produce a single compound image. Using a 192-element, 3.5-MHz, λ-pitch transducer, it is demonstrated from...... tissue-phantom measurements that the speckle is reduced and the contrast resolution improved when applying synthetic aperture compound imaging. At a depth of 4 cm, the size of the synthesized apertures is optimized for lesion detection based on the speckle information density. This is a performance...

  16. Synthetic biology character and impact

    Pade, Christian; Wigger, Henning; Gleich, Arnim

    2015-01-01

    Synthetic Biology is already an object of intensive debate. However, to a great extent the discussion to date has been concerned with fundamental ethical, religious and philosophical questions. By contrast, based on an investigation of the field’s scientific and technological character, this book focuses on new functionalities provided by synthetic biology and explores the associated opportunities and risks. Following an introduction to the subject and a discussion of the most central paradigms and methodologies, the book provides an overview of the structure of this field of science and technology. It informs the reader about the current stage of development, as well as topical problems and potential opportunities in important fields of application. But not only the science itself is in focus. In order to investigate its broader impact, ecological as well as ethical implications will be considered, paving the way for a discussion of responsibilities in the context of a field at a transitional crossroads be...

  17. Synthetic greenhouse gases under control

    This article discusses new Swiss regulations on the use of synthetic materials that posses a considerable greenhouse-warming potential. Synthetic materials such as hydro-chlorofluorocarbons HCFCs, perfluoride-hydrocarbons and sulphur hexafluoride have, in recent years, replaced chlorofluorocarbons CFCs, which were banned on account of their ozone depletion characteristics. The use of these persistent substances is now being limited to applications where more environment-friendly alternatives are not available. The measures decreed in the legislation, which include a general ban on HCFCs as of 2004 and a ban on the export of installations and equipment that use ozone-depleting refrigerants are described. Details on the legislation's effects on the Swiss refrigeration industry are listed and discussed

  18. Airborne synthetic aperture acoustic imaging.

    Soumekh, M

    1997-01-01

    This paper presents a system model and inversion for airborne synthetic aperture acoustic (SAA) imaging. The system model accurately represents the intercation of the acoustic source and the target region at near range values. Moreover, the model incorporates the fact that the relative speed of the vehicle's (transmitter/receiver) with respect to the target region is comparable to the acoustic wave propagation speed. The inversion utilizes the principle of spectral decomposition of spherical phase functions to develop a wavefront reconstruction method from SAA data. Processing issues and selection of appropriate acoustic FM-CW sources are discussed. Results are provided that exhibit the superior accuracy of the proposed SAA system model and inversion over their synthetic aperture radar (SAR) counterpart in which the vehicle's speed is assumed to be much smaller than the wave propagation speed. PMID:18282912

  19. Optimizing Synthetic Aperture Compound Imaging

    Hansen, Jens Munk; Jensen, Jørgen Arendt

    2012-01-01

    Spatial compound images are constructed from synthetic aperture data acquired using a linear phased-array transducer. Compound images of wires, tissue, and cysts are created using a method, which allows both transmit and receive compounding without any loss in temporal resolution. Similarly to...... optimal for lesion detection. Synthetic aperture data are acquired from unfocused emissions and 154 compound images are constructed by synthesizing different aperture configurations with more or less compounding, all maintaining a constant resolution across depth corresponding to an f-number of 2.0 for...... transmit and receive. The same configurations are used for scanning a phantom with cysts, and it is demonstrated how an improved cysts contrast follows from an aperture configuration, which gives a higher value for the performance measure extracted from the phantom without cysts. A correlation value R = 0...

  20. Ionoluminescence (IL) of synthetic diamonds

    The optical properties of natural and synthetic diamonds have been extensively characterized in the past by absorption and luminescence. The use of such techniques as cathodoluminescence, photoluminescence, photoluminescence excitation and electron spin and paramagnetic resonance has resulted in the identification of many impurity and defect related optical centres in diamond. Of the impurities found in diamond, nitrogen is by far the most abundant and hence responsible for most of the optical properties. The development of diamond synthesis methods has resulted in the discovery of a number of a new optically active impurities and defects which are introduced during the growth process. These include Si, O, Ni and B. In this study we identify a number of defect and impurity related centres in two commercially produced synthetic diamond samples by using the novel technique of ionoluminescence. The results are consistent with previous studies which have shown that Ni impurities segregate in [111] growth sector. (authors)

  1. Multifocal interferometric synthetic aperture microscopy

    Xu, Yang; Chng, Xiong Kai Benjamin; Adie, Steven G.; Boppart, Stephen A.; Scott Carney, P.

    2014-01-01

    There is an inherent trade-off between transverse resolution and depth of field (DOF) in optical coherence tomography (OCT) which becomes a limiting factor for certain applications. Multifocal OCT and interferometric synthetic aperture microscopy (ISAM) each provide a distinct solution to the trade-off through modification to the experiment or via post-processing, respectively. In this paper, we have solved the inverse problem of multifocal OCT and present a general algorithm for combining mu...

  2. Synthetically Simple, Highly Resilient Hydrogels

    Cui, Jun; Lackey, Melissa A.; Madkour, Ahmad E.; Saffer, Erika M.; Griffin, David M.; Bhatia, Surita R.; Crosby, Alfred J.; Tew, Gregory N.

    2012-01-01

    Highly resilient synthetic hydrogels were synthesized by using the efficient thiol-norbornene chemistry to cross-link hydrophilic poly(ethylene glycol) (PEG) and hydrophobic polydimethylsiloxane (PDMS) polymer chains. The swelling and mechanical properties of the hydrogels were well-controlled by the relative amounts of PEG and PDMS. In addition, the mechanical energy storage efficiency (resilience) was more than 97% at strains up to 300%. This is comparable with one of the most resilient mat...

  3. Synthetic Studies directed towards Asmarines

    2013-01-01

    The present thesis is focused on the design of synthetic routes towards asmarine analogues. Asmarines are marine natural products isolated from the sponges Raspalia sp. The asmarine molecule contains a seven-membered ring fused with a purine core. This tetrahydrodiazepinopurine moiety has previously been constructed for example by ringclosing metathesis (RCM). We were focused on developing this RCM reaction pathway further, in order to introduce a chiral centre to the 7-membered ring. The att...

  4. Word selection affects perceptions of synthetic biology

    Tonidandel Scott; Bye-Nagel Kyri; Snell Sam; Pearson Brianna; Heyer Laurie J; Campbell A Malcolm

    2011-01-01

    Abstract Members of the synthetic biology community have discussed the significance of word selection when describing synthetic biology to the general public. In particular, many leaders proposed the word "create" was laden with negative connotations. We found that word choice and framing does affect public perception of synthetic biology. In a controlled experiment, participants perceived synthetic biology more negatively when "create" was used to describe the field compared to "construct" (...

  5. Microbial synthetic biology for human therapeutics

    Jain, Aastha; Bhatia, Pooja; Chugh, Archana

    2012-01-01

    The emerging field of synthetic biology holds tremendous potential for developing novel drugs to treat various human conditions. The current study discusses the scope of synthetic biology for human therapeutics via microbial approach. In this context, synthetic biology aims at designing, engineering and building new microbial synthetic cells that do not pre-exist in nature as well as re-engineer existing microbes for synthesis of therapeutic products. It is expected that the construction of n...

  6. Understanding the risk of synthetic CDOs

    Michael S. Gibson

    2004-01-01

    Synthetic collateralized debt obligations, or synthetic CDOs, are popular vehicles for trading the credit risk of a portfolio of assets. Following a brief summary of the development of the synthetic CDO market, I draw on recent innovations in modeling to present a pricing model for CDO tranches that does not require Monte Carlo simulation. I use the model to analyze the risk characteristics of the tranches of synthetic CDOs. The analysis shows that although the more junior CDO tranches -- equ...

  7. Cell microencapsulation with synthetic polymers.

    Olabisi, Ronke M

    2015-02-01

    The encapsulation of cells into polymeric microspheres or microcapsules has permitted the transplantation of cells into human and animal subjects without the need for immunosuppressants. Cell-based therapies use donor cells to provide sustained release of a therapeutic product, such as insulin, and have shown promise in treating a variety of diseases. Immunoisolation of these cells via microencapsulation is a hotly investigated field, and the preferred material of choice has been alginate, a natural polymer derived from seaweed due to its gelling conditions. Although many natural polymers tend to gel in conditions favorable to mammalian cell encapsulation, there remain challenges such as batch to batch variability and residual components from the original source that can lead to an immune response when implanted into a recipient. Synthetic materials have the potential to avoid these issues; however, historically they have required harsh polymerization conditions that are not favorable to mammalian cells. As research into microencapsulation grows, more investigators are exploring methods to microencapsulate cells into synthetic polymers. This review describes a variety of synthetic polymers used to microencapsulate cells. PMID:24771675

  8. Approaches to synthetic platelet analogs.

    Modery-Pawlowski, Christa L; Tian, Lewis L; Pan, Victor; McCrae, Keith R; Mitragotri, Samir; Sen Gupta, Anirban

    2013-01-01

    Platelet transfusion is routinely used for treating bleeding complications in patients with hematologic or oncologic clotting disorders, chemo/radiotherapy-induced myelosuppression, trauma and surgery. Currently, these transfusions mostly use allogeneic platelet concentrates, while products like lyophilized platelets, cold-stored platelets and infusible platelet membranes are under investigation. These natural platelet-based products pose considerable risks of contamination, resulting in short shelf-life (3-5 days). Recent advances in pathogen reduction technologies have increased shelf-life to ~7 days. Furthermore, natural platelets are short in supply and also cause several biological side effects. Hence, there is significant clinical interest in platelet-mimetic synthetic analogs that can allow long storage-life and minimum side effects. Accordingly, several designs have been studied which decorate synthetic particles with motifs that promote platelet-mimetic adhesion or aggregation. Recent refinement in this design involves combining the adhesion and aggregation functionalities on a single particle platform. Further refinement is being focused on constructing particles that also mimic natural platelet's shape, size and elasticity, to influence margination and wall-interaction. The optimum design of a synthetic platelet analog would require efficient integration of platelet's physico-mechanical properties and biological functionalities. We present a comprehensive review of these approaches and provide our opinion regarding the future directions of this research. PMID:23092864

  9. Different lattice geometries with synthetic dimension

    Suszalski, Dominik; Zakrzewski, Jakub

    2016-01-01

    The possibility of creating different geometries with the help of an extra synthetic dimension in optical lattices is studied. Additional linear potential and Raman assisted tunnelings are used to engineer well controlled tunnelings between available states. The great flexibility of the system allows us to obtain different geometries of synthetic lattices with possibility of adding synthetic gauge fields.

  10. Effect of sialoadenectomy and synthetic human urogastrone on healing of chronic gastric ulcers in rats

    Poulsen, Steen Seier; Nexø, Ebba

    1986-01-01

    The effect of extirpation of the submandibular glands, an exocrine organ for epidermal growth factor/urogastrone (EGF/URO), and the effect of oral administration of synthetic human (EGF/URO) on healing of chronic gastric ulcers in rats has been investigated. Removal of the submandibular glands...... administration of synthetic human EGF/URO and cimetidine further increased healing of gastric ulcers compared with administration of each substance. Neither synthetic human EGF/URO, nor removal of the submandibular glands had any influence on gastric acid secretion. This study showed that the submandibular...... delayed healing of chronic gastric ulcers when examined after 50, 100, and 200 days. Oral administration of synthetic human EGF/URO stimulated gastric ulcer healing when examined after 25 and 50 days of treatment. The effect of synthetic human EGF/URO was comparable with that of cimetidine. The combined...