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Sample records for energetics ketone bodies

  1. Ketone bodies as signaling metabolites

    PubMed Central

    Newman, John C.; Verdin, Eric

    2014-01-01

    Traditionally, the ketone body β-hydroxybutyrate (βOHB) has been looked upon as a carrier of energy from liver to peripheral tissues during fasting or exercise. However, βOHB also signals via extracellular receptors and acts as an endogenous inhibitor of histone deacetylases (HDACs). These recent findings support a model in which βOHB functions to link the environment, in this case the diet, and gene expression via chromatin modifications. Here, we review the regulation and functions of ketone bodies, the relationship between ketone bodies and calorie restriction, and the implications of HDAC inhibition by the ketone body βOHB in the modulation of metabolism, and diseases of aging. PMID:24140022

  2. Ketone body metabolism and cardiovascular disease

    PubMed Central

    Cotter, David G.; Schugar, Rebecca C.

    2013-01-01

    Ketone bodies are metabolized through evolutionarily conserved pathways that support bioenergetic homeostasis, particularly in brain, heart, and skeletal muscle when carbohydrates are in short supply. The metabolism of ketone bodies interfaces with the tricarboxylic acid cycle, β-oxidation of fatty acids, de novo lipogenesis, sterol biosynthesis, glucose metabolism, the mitochondrial electron transport chain, hormonal signaling, intracellular signal transduction pathways, and the microbiome. Here we review the mechanisms through which ketone bodies are metabolized and how their signals are transmitted. We focus on the roles this metabolic pathway may play in cardiovascular disease states, the bioenergetic benefits of myocardial ketone body oxidation, and prospective interactions among ketone body metabolism, obesity, metabolic syndrome, and atherosclerosis. Ketone body metabolism is noninvasively quantifiable in humans and is responsive to nutritional interventions. Therefore, further investigation of this pathway in disease models and in humans may ultimately yield tailored diagnostic strategies and therapies for specific pathological states. PMID:23396451

  3. Obligate Role for Ketone Body Oxidation in Neonatal Metabolic Homeostasis*

    PubMed Central

    Cotter, David G.; d'Avignon, D. André; Wentz, Anna E.; Weber, Mary L.; Crawford, Peter A.

    2011-01-01

    To compensate for the energetic deficit elicited by reduced carbohydrate intake, mammals convert energy stored in ketone bodies to high energy phosphates. Ketone bodies provide fuel particularly to brain, heart, and skeletal muscle in states that include starvation, adherence to low carbohydrate diets, and the neonatal period. Here, we use novel Oxct1−/− mice, which lack the ketolytic enzyme succinyl-CoA:3-oxo-acid CoA-transferase (SCOT), to demonstrate that ketone body oxidation is required for postnatal survival in mice. Although Oxct1−/− mice exhibit normal prenatal development, all develop ketoacidosis, hypoglycemia, and reduced plasma lactate concentrations within the first 48 h of birth. In vivo oxidation of 13C-labeled β-hydroxybutyrate in neonatal Oxct1−/− mice, measured using NMR, reveals intact oxidation to acetoacetate but no contribution of ketone bodies to the tricarboxylic acid cycle. Accumulation of acetoacetate yields a markedly reduced β-hydroxybutyrate:acetoacetate ratio of 1:3, compared with 3:1 in Oxct1+ littermates. Frequent exogenous glucose administration to actively suckling Oxct1−/− mice delayed, but could not prevent, lethality. Brains of newborn SCOT-deficient mice demonstrate evidence of adaptive energy acquisition, with increased phosphorylation of AMP-activated protein kinase α, increased autophagy, and 2.4-fold increased in vivo oxidative metabolism of [13C]glucose. Furthermore, [13C]lactate oxidation is increased 1.7-fold in skeletal muscle of Oxct1−/− mice but not in brain. These results indicate the critical metabolic roles of ketone bodies in neonatal metabolism and suggest that distinct tissues exhibit specific metabolic responses to loss of ketone body oxidation. PMID:21209089

  4. Ketone-body utilization by homogenates of adult rat brain

    SciTech Connect

    Lopes-Cardozo, M.; Klein, W.

    1982-06-01

    The regulation of ketone-body metabolism and the quantitative importance of ketone bodies as lipid precursors in adult rat brain has been studied in vitro. Utilization of ketone bodies and of pyruvate by homogenates of adult rat brain was measured and the distribution of /sup 14/C from (3-/sup 14/C)ketone bodies among the metabolic products was analysed. The rate of ketone-body utilization was maximal in the presence of added Krebs-cycle intermediates and uncouplers of oxidative phosphorylation. The consumption of acetoacetate was faster than that of D-3-hydroxybutyrate, whereas, pyruvate produced twice as much acetyl-CoA as acetoacetate under optimal conditions. Millimolar concentrations of ATP in the presence of uncoupler lowered the consumption of ketone bodies but not of pyruvate. Indirect evidence is presented suggesting that ATP interferes specifically with the mitochondrial uptake of ketone bodies. Interconversion of ketone bodies and the accumulation of acid-soluble intermediates (mainly citrate and glutamate) accounted for the major part of ketone-body utilization, whereas only a small part was oxidized to CO/sub 2/. Ketone bodies were not incorporated into lipids or protein. We conclude that adult rat-brain homogenates use ketone bodies exclusively for oxidative purposes.

  5. Inborn errors of ketone body utilization.

    PubMed

    Hori, Tomohiro; Yamaguchi, Seiji; Shinkaku, Haruo; Horikawa, Reiko; Shigematsu, Yosuke; Takayanagi, Masaki; Fukao, Toshiyuki

    2015-01-01

    Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency and mitochondrial acetoacetyl-CoA thiolase (beta-ketothiolase or T2) deficiency are classified as autosomal recessive disorders of ketone body utilization characterized by intermittent ketoacidosis. Patients with mutations retaining no residual activity on analysis of expression of mutant cDNA are designated as severe genotype, and patients with at least one mutation retaining significant residual activity, as mild genotype. Permanent ketosis is a pathognomonic characteristic of SCOT-deficient patients with severe genotype. Patients with mild genotype, however, may not have permanent ketosis, although they may develop severe ketoacidotic episodes similar to patients with severe genotype. Permanent ketosis has not been reported in T2 deficiency. In T2-deficient patients with severe genotype, biochemical diagnosis is done on urinary organic acid analysis and blood acylcarnitine analysis to observe characteristic findings during both ketoacidosis and non-episodic conditions. In Japan, however, it was found that T2-deficient patients with mild genotype are common, and typical profiles were not identified on these analyses. Based on a clinical study of ketone body utilization disorders both in Japan and worldwide, we have developed guidelines for disease diagnosis and treatment. These diseases are treatable by avoiding fasting and by providing early infusion of glucose, which enable the patients to grow without sequelae. PMID:25559898

  6. Successful adaptation to ketosis by mice with tissue-specific deficiency of ketone body oxidation

    PubMed Central

    Cotter, David G.; Schugar, Rebecca C.; Wentz, Anna E.; André d'Avignon, D.

    2013-01-01

    During states of low carbohydrate intake, mammalian ketone body metabolism transfers energy substrates originally derived from fatty acyl chains within the liver to extrahepatic organs. We previously demonstrated that the mitochondrial enzyme coenzyme A (CoA) transferase [succinyl-CoA:3-oxoacid CoA transferase (SCOT), encoded by nuclear Oxct1] is required for oxidation of ketone bodies and that germline SCOT-knockout (KO) mice die within 48 h of birth because of hyperketonemic hypoglycemia. Here, we use novel transgenic and tissue-specific SCOT-KO mice to demonstrate that ketone bodies do not serve an obligate energetic role within highly ketolytic tissues during the ketogenic neonatal period or during starvation in the adult. Although transgene-mediated restoration of myocardial CoA transferase in germline SCOT-KO mice is insufficient to prevent lethal hyperketonemic hypoglycemia in the neonatal period, mice lacking CoA transferase selectively within neurons, cardiomyocytes, or skeletal myocytes are all viable as neonates. Like germline SCOT-KO neonatal mice, neonatal mice with neuronal CoA transferase deficiency exhibit increased cerebral glycolysis and glucose oxidation, and, while these neonatal mice exhibit modest hyperketonemia, they do not develop hypoglycemia. As adults, tissue-specific SCOT-KO mice tolerate starvation, exhibiting only modestly increased hyperketonemia. Finally, metabolic analysis of adult germline Oxct1+/− mice demonstrates that global diminution of ketone body oxidation yields hyperketonemia, but hypoglycemia emerges only during a protracted state of low carbohydrate intake. Together, these data suggest that, at the tissue level, ketone bodies are not a required energy substrate in the newborn period or during starvation, but rather that integrated ketone body metabolism mediates adaptation to ketogenic nutrient states. PMID:23233542

  7. Cardiomyocyte-specific deficiency of ketone body metabolism promotes accelerated pathological remodeling

    PubMed Central

    Schugar, Rebecca C.; Moll, Ashley R.; André d’Avignon, D.; Weinheimer, Carla J.; Kovacs, Attila; Crawford, Peter A.

    2014-01-01

    Objective Exploitation of protective metabolic pathways within injured myocardium still remains an unclarified therapeutic target in heart disease. Moreover, while the roles of altered fatty acid and glucose metabolism in the failing heart have been explored, the influence of highly dynamic and nutritionally modifiable ketone body metabolism in the regulation of myocardial substrate utilization, mitochondrial bioenergetics, reactive oxygen species (ROS) generation, and hemodynamic response to injury remains undefined. Methods Here we use mice that lack the enzyme required for terminal oxidation of ketone bodies, succinyl-CoA:3-oxoacid CoA transferase (SCOT) to determine the role of ketone body oxidation in the myocardial injury response. Tracer delivery in ex vivo perfused hearts coupled to NMR spectroscopy, in vivo high-resolution echocardiographic quantification of cardiac hemodynamics in nutritionally and surgically modified mice, and cellular and molecular measurements of energetic and oxidative stress responses are performed. Results While germline SCOT-knockout (KO) mice die in the early postnatal period, adult mice with cardiomyocyte-specific loss of SCOT (SCOT-Heart-KO) remarkably exhibit no overt metabolic abnormalities, and no differences in left ventricular mass or impairments of systolic function during periods of ketosis, including fasting and adherence to a ketogenic diet. Myocardial fatty acid oxidation is increased when ketones are delivered but cannot be oxidized. To determine the role of ketone body oxidation in the remodeling ventricle, we induced pressure overload injury by performing transverse aortic constriction (TAC) surgery in SCOT-Heart-KO and αMHC-Cre control mice. While TAC increased left ventricular mass equally in both groups, at four weeks post-TAC, myocardial ROS abundance was increased in myocardium of SCOT-Heart-KO mice, and mitochondria and myofilaments were ultrastructurally disordered. Eight weeks post-TAC, left ventricular

  8. Metabolic reprogramming induced by ketone bodies diminishes pancreatic cancer cachexia

    PubMed Central

    2014-01-01

    Background Aberrant energy metabolism is a hallmark of cancer. To fulfill the increased energy requirements, tumor cells secrete cytokines/factors inducing muscle and fat degradation in cancer patients, a condition known as cancer cachexia. It accounts for nearly 20% of all cancer-related deaths. However, the mechanistic basis of cancer cachexia and therapies targeting cancer cachexia thus far remain elusive. A ketogenic diet, a high-fat and low-carbohydrate diet that elevates circulating levels of ketone bodies (i.e., acetoacetate, β-hydroxybutyrate, and acetone), serves as an alternative energy source. It has also been proposed that a ketogenic diet leads to systemic metabolic changes. Keeping in view the significant role of metabolic alterations in cancer, we hypothesized that a ketogenic diet may diminish glycolytic flux in tumor cells to alleviate cachexia syndrome and, hence, may provide an efficient therapeutic strategy. Results We observed reduced glycolytic flux in tumor cells upon treatment with ketone bodies. Ketone bodies also diminished glutamine uptake, overall ATP content, and survival in multiple pancreatic cancer cell lines, while inducing apoptosis. A decrease in levels of c-Myc, a metabolic master regulator, and its recruitment on glycolytic gene promoters, was in part responsible for the metabolic phenotype in tumor cells. Ketone body-induced intracellular metabolomic reprogramming in pancreatic cancer cells also leads to a significantly diminished cachexia in cell line models. Our mouse orthotopic xenograft models further confirmed the effect of a ketogenic diet in diminishing tumor growth and cachexia. Conclusions Thus, our studies demonstrate that the cachectic phenotype is in part due to metabolic alterations in tumor cells, which can be reverted by a ketogenic diet, causing reduced tumor growth and inhibition of muscle and body weight loss. PMID:25228990

  9. Advanced selective non-invasive ketone body detection sensors based on new ionophores

    NASA Astrophysics Data System (ADS)

    Sathyapalan, A.; Sarswat, P. K.; Zhu, Y.; Free, M. L.

    2014-12-01

    New molecules and methods were examined that can be used to detect trace level ketone bodies. Diseases such as type 1 diabetes, childhood hypo-glycaemia-growth hormone deficiency, toxic inhalation, and body metabolism changes are linked with ketone bodies concentration. Here we introduce, selective ketone body detection sensors based on small, environmentally friendly organic molecules with Lewis acid additives. Density functional theory (DFT) simulation of the sensor molecules (Bromo-acetonaphthone tungstate (BANT) and acetonaphthophenyl ether propiono hydroxyl tungstate (APPHT)), indicated a fully relaxed geometry without symmetry attributes and specific coordination which enhances ketone bodies sensitivity. A portable sensing unit was made in which detection media containing ketone bodies at low concentration and new molecules show color change in visible light as well as unique irradiance during UV illumination. RGB analysis, electrochemical tests, SEM characterization, FTIR, absorbance and emission spectroscopy were also performed in order to validate the ketone sensitivity of these new molecules.

  10. The effect of ketone bodies on renal ammoniogenesis

    PubMed Central

    Lemieux, Guy; Vinay, Patrick; Robitaille, Pierre; Plante, Gérard E.; Lussier, Yolande; Martin, Pierre

    1971-01-01

    Infusion of ketone bodies to ammonium chloride-loaded acidotic dogs was found to induce significant reduction in urinary excretion of ammonia. This effect could not be attributed to urinary pH variations. Total ammonia production by the left kidney was measured in 25 animals infused during 90 min with the sodium salt of D,L-β-hydroxybutyric acid adjusted to pH 6.0 or 4.2. Ketonemia averaged 4.5 mM/liter. In all experiments the ammonia content of both urine and renal venous blood fell markedly so that ammoniogenesis was depressed by 60% or more within 60 min after the onset of infusion. Administration of equimolar quantities of sodium acetoacetate adjusted to pH 6.0 resulted in a 50% decrease in renal ammonia production. Infusion of ketone bodies adjusted to pH 6.0 is usually accompanied by a small increase in extracellular bicarbonate (3.7 mM/liter). However infusion of D,L-sodium lactate or sodium bicarbonate in amounts sufficient to induce a similar rise in plasma bicarbonate resulted in only a slight decrement in ammonia production (15%). The continuous infusion of 5% mannitol alone during 90-150 min failed to influence renal ammoniogenesis. Infusion of pure sodium-free β-hydroxybutyric acid prepared by ion exchange (pH 2.2) resulted in a 50% decrease in renal ammoniogenesis in spite of the fact that both urinary pH and plasma bicarbonate fell significantly. During all experiments where ketones were infused, the renal extraction of glutamine became negligible as the renal glutamine arteriovenous difference was abolished. Renal hemodynamics did not vary significantly. Infusion of β-hydroxybutyrate into the left renal artery resulted in a rapid decrease in ammoniogenesis by the perfused kidney. The present study indicates that ketone bodies exert their inhibitory influence within the renal tubular cell. Since their effect is independent of urinary or systemic acid-base changes, it is suggested that they depress renal ammoniogenesis by preventing the

  11. Fenofibrate Induces Ketone Body Production in Melanoma and Glioblastoma Cells

    PubMed Central

    Grabacka, Maja M.; Wilk, Anna; Antonczyk, Anna; Banks, Paula; Walczyk-Tytko, Emilia; Dean, Matthew; Pierzchalska, Malgorzata; Reiss, Krzysztof

    2016-01-01

    Ketone bodies [beta-hydroxybutyrate (bHB) and acetoacetate] are mainly produced in the liver during prolonged fasting or starvation. bHB is a very efficient energy substrate for sustaining ATP production in peripheral tissues; importantly, its consumption is preferred over glucose. However, the majority of malignant cells, particularly cancer cells of neuroectodermal origin such as glioblastoma, are not able to use ketone bodies as a source of energy. Here, we report a novel observation that fenofibrate, a synthetic peroxisome proliferator-activated receptor alpha (PPARa) agonist, induces bHB production in melanoma and glioblastoma cells, as well as in neurospheres composed of non-transformed cells. Unexpectedly, this effect is not dependent on PPARa activity or its expression level. The fenofibrate-induced ketogenesis is accompanied by growth arrest and downregulation of transketolase, but the NADP/NADPH and GSH/GSSG ratios remain unaffected. Our results reveal a new, intriguing aspect of cancer cell biology and highlight the benefits of fenofibrate as a supplement to both canonical and dietary (ketogenic) therapeutic approaches against glioblastoma. PMID:26869992

  12. Ketones urine test

    MedlinePlus

    Ketone bodies - urine; Urine ketones; Ketoacidosis - urine ketones test; Diabetic ketoacidosis - urine ketones test ... Urine ketones are usually measured as a "spot test." This is available in a test kit that ...

  13. Ketone body therapy: from the ketogenic diet to the oral administration of ketone ester

    PubMed Central

    Hashim, Sami A.; VanItallie, Theodore B.

    2014-01-01

    Ketone bodies (KBs), acetoacetate and β-hydroxybutyrate (βHB), were considered harmful metabolic by-products when discovered in the mid-19th century in the urine of patients with diabetic ketoacidosis. It took physicians many years to realize that KBs are normal metabolites synthesized by the liver and exported into the systemic circulation to serve as an energy source for most extrahepatic tissues. Studies have shown that the brain (which normally uses glucose for energy) can readily utilize KBs as an alternative fuel. Even when there is diminished glucose utilization in cognition-critical brain areas, as may occur early in Alzheimer’s disease (AD), there is preliminary evidence that these same areas remain capable of metabolizing KBs. Because the ketogenic diet (KD) is difficult to prepare and follow, and effectiveness of KB treatment in certain patients may be enhanced by raising plasma KB levels to ≥2 mM, KB esters, such as 1,3-butanediol monoester of βHB and glyceryl-tris-3-hydroxybutyrate, have been devised. When administered orally in controlled dosages, these esters can produce plasma KB levels comparable to those achieved by the most rigorous KD, thus providing a safe, convenient, and versatile new approach to the study and potential treatment of a variety of diseases, including epilepsy, AD, and Parkinson’s disease. PMID:24598140

  14. Ketone body therapy: from the ketogenic diet to the oral administration of ketone ester.

    PubMed

    Hashim, Sami A; VanItallie, Theodore B

    2014-09-01

    Ketone bodies (KBs), acetoacetate and β-hydroxybutyrate (βHB), were considered harmful metabolic by-products when discovered in the mid-19th century in the urine of patients with diabetic ketoacidosis. It took physicians many years to realize that KBs are normal metabolites synthesized by the liver and exported into the systemic circulation to serve as an energy source for most extrahepatic tissues. Studies have shown that the brain (which normally uses glucose for energy) can readily utilize KBs as an alternative fuel. Even when there is diminished glucose utilization in cognition-critical brain areas, as may occur early in Alzheimer's disease (AD), there is preliminary evidence that these same areas remain capable of metabolizing KBs. Because the ketogenic diet (KD) is difficult to prepare and follow, and effectiveness of KB treatment in certain patients may be enhanced by raising plasma KB levels to ≥2 mM, KB esters, such as 1,3-butanediol monoester of βHB and glyceryl-tris-3-hydroxybutyrate, have been devised. When administered orally in controlled dosages, these esters can produce plasma KB levels comparable to those achieved by the most rigorous KD, thus providing a safe, convenient, and versatile new approach to the study and potential treatment of a variety of diseases, including epilepsy, AD, and Parkinson's disease. PMID:24598140

  15. Human ketone body production and utilization studied using tracer techniques: Regulation by free fatty acids, insulin, catecholamines, and thyroid hormones

    SciTech Connect

    Keller, U.; Lustenberger, M.; Mueller-Brand, J.G.; Gerber, P.P.; Stauffacher, W.

    1989-05-01

    Ketone body concentrations fluctuate markedly during physiological and pathological conditions. Tracer techniques have been developed in recent years to study production, utilization, and the metabolic clearance rate of ketone bodies. This review describes data on the roles of insulin, catecholamines, and thyroid hormones in the regulation of ketone body kinetics. The data indicate that insulin lowers ketone body concentrations by three independent mechanisms: first, it inhibits lipolysis, and thus lowers free fatty acid availability for ketogenesis; second, it restrains ketone body production within the liver; third, it enhances peripheral ketone body utilization. To assess these effects in humans in vivo, experimental models were developed to study insulin effects with controlled concentrations of free fatty acids, insulin, glucagon, and ketone bodies. Presently available data also support an important role of catecholamines in increasing ketone body concentrations. Evidence was presented that norepinephrine increases ketogenesis not only by stimulating lipolysis, and thus releasing free fatty acids, but also by increasing intrahepatic ketogenesis. Thyroid hormone availability was associated with lipolysis and ketogenesis. Ketone body concentrations after an overnight fast were only modestly elevated in hyperthyroidism resulting from increased peripheral ketone body clearance. There was a significant correlation between serum triiodothyronine levels and the ketone body metabolic clearance rate. Thus, ketone body homeostasis in human subjects resulted from the interaction of hormones such as insulin, catecholamines, and thyroid hormones regulating lipolysis, intrahepatic ketogenesis, and peripheral ketone body utilization. 58 references.

  16. Skeletal muscle PGC-1α modulates systemic ketone body homeostasis and ameliorates diabetic hyperketonemia in mice

    PubMed Central

    Svensson, Kristoffer; Albert, Verena; Cardel, Bettina; Salatino, Silvia; Handschin, Christoph

    2016-01-01

    Ketone bodies are crucial energy substrates during states of low carbohydrate availability. However, an aberrant regulation of ketone body homeostasis can lead to complications such as diabetic ketoacidosis. Exercise and diabetes affect systemic ketone body homeostasis, but the regulation of ketone body metabolism is still enigmatic. Using mice with either a knockout or overexpression of the peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) in skeletal muscle, we show that PGC-1α regulates ketolytic gene transcription in muscle. Furthermore, ketone body homeostasis of these mice was investigated during fasting, exercise, ketogenic diet feeding and after streptozotocin injection. In response to these ketogenic stimuli, we show that modulation of PGC-1α levels in muscle affects systemic ketone body homeostasis. Moreover, our data demonstrate that skeletal muscle PGC-1α is necessary for the enhanced ketolytic capacity in response to exercise training and overexpression of PGC-1α in muscle enhances systemic ketolytic capacity and is sufficient to ameliorate diabetic hyperketonemia in mice. Using cultured myotubes, we also show that the transcription factor estrogen related receptor α (ERRα) is a partner of PGC-1α in the regulation of ketolytic gene transcription. Collectively, these results demonstrate a central role of skeletal muscle PGC-1α in the transcriptional regulation of systemic ketolytic capacity. PMID:26849960

  17. Ketones blood test

    MedlinePlus

    ... Ketones - serum; Nitroprusside test; Ketone bodies - serum; Ketones - blood ... A blood sample is needed. ... When the needle is inserted to draw blood, some people feel slight ... there may be some throbbing or a slight bruise. This soon ...

  18. Lauric Acid Stimulates Ketone Body Production in the KT-5 Astrocyte Cell Line.

    PubMed

    Nonaka, Yudai; Takagi, Tetsuo; Inai, Makoto; Nishimura, Shuhei; Urashima, Shogo; Honda, Kazumitsu; Aoyama, Toshiaki; Terada, Shin

    2016-08-01

    Coconut oil has recently attracted considerable attention as a potential Alzheimer's disease therapy because it contains large amounts of medium-chain fatty acids (MCFAs) and its consumption is thought to stimulate hepatic ketogenesis, supplying an alternative energy source for brains with impaired glucose metabolism. In this study, we first reevaluated the responses of plasma ketone bodies to oral administration of coconut oil to rats. We found that the coconut oil-induced increase in plasma ketone body concentration was negligible and did not significantly differ from that observed after high-oleic sunflower oil administration. In contrast, the administration of coconut oil substantially increased the plasma free fatty acid concentration and lauric acid content, which is the major MCFA in coconut oil. Next, to elucidate whether lauric acid can activate ketogenesis in astrocytes with the capacity to generate ketone bodies from fatty acids, we treated the KT-5 astrocyte cell line with 50 and 100 μM lauric acid for 4 h. The lauric acid treatments increased the total ketone body concentration in the cell culture supernatant to a greater extent than oleic acid, suggesting that lauric acid can directly and potently activate ketogenesis in KT-5 astrocytes. These results suggest that coconut oil intake may improve brain health by directly activating ketogenesis in astrocytes and thereby by providing fuel to neighboring neurons. PMID:27430387

  19. Suggested involvement of ketone bodies in the pathogenesis of the metabolic syndrome.

    PubMed

    Alexandre, Adolfo

    2013-05-01

    Untreated brain mitochondria are strong producers of H2O2. High peroxide production (in the presence of glutamate and pyruvate) is strictly succinate-dependent. Importantly, it is inhibited by the ketone body acetoacetate (AcAc) starting at 10 μM (maximal effect at 0.5mM). Butyrate derives from the fermentation of prebiotics, is present physiologically in the colon and is a strong producer of AcAc: indeed butyrate induces in the colon the transcription of mitochondrial 3-hydroxy-3-methyl glutarylCoA (HMGCoA) synthase, a key enzyme in ketone body synthesis. Obesity and insulin resistance were shown to be dependent on increased permeability of the colon epithelium to bacterial lipopolysaccharide (LPS); the process is evident particularly upon ingestion of lipids (a peroxidative event, inhibited by vitamin E) and is likely sensitive to AcAc. The oxidation of butyrate and the production of AcAc in the colon appear to be inhibited by high luminal sulphides and high NH3, a situation that presumably facilitates LPS permeation (on the contrary beta-hydroxy-butyrate oxidation is not inhibited). It is proposed that these damaging events may be opposed by the delivery of ketone bodies directly to the colon. PMID:23466063

  20. Role of VMH ketone bodies in adjusting caloric intake to increased dietary fat content in DIO and DR rats.

    PubMed

    Le Foll, Christelle; Dunn-Meynell, Ambrose A; Miziorko, Henry M; Levin, Barry E

    2015-05-15

    The objective of this study was to determine the potential role of astrocyte-derived ketone bodies in regulating the early changes in caloric intake of diet induced-obese (DIO) versus diet-resistant (DR) rats fed a 31.5% fat high-energy (HE) diet. After 3 days on chow or HE diet, DR and DIO rats were assessed for their ventromedial hypothalamic (VMH) ketone bodies levels and neuronal ventromedial hypothalamic nucleus (VMN) sensing using microdialysis coupled to continuous food intake monitoring and calcium imaging in dissociated neurons, respectively. DIO rats ate more than DR rats over 3 days of HE diet intake. On day 3 of HE diet intake, DR rats reduced their caloric intake while DIO rats remained hyperphagic. Local VMH astrocyte ketone bodies production was similar between DR and DIO rats during the first 6 h after dark onset feeding but inhibiting VMH ketone body production in DR rats on day 3 transiently returned their intake of HE diet to the level of DIO rats consuming HE diet. In addition, dissociated VMN neurons from DIO and DR rats were equally sensitive to the largely excitatory effects of β-hydroxybutyrate. Thus while DR rats respond to increased VMH ketone levels by decreasing their intake after 3 days of HE diet, this is not the case of DIO rats. These data suggest that DIO inherent leptin resistance prevents ketone bodies inhibitory action on food intake. PMID:25786485

  1. Caloric restriction increases ketone bodies metabolism and preserves blood flow in aging brain

    PubMed Central

    Lin, Ai-Ling; Zhang, Wei; Gao, Xiaoli; Watts, Lora

    2015-01-01

    Caloric restriction (CR) has been shown to increase the life span and health span of a broad range of species. However, CR effects on in vivo brain functions are far from explored. In this study, we used multimetric neuroimaging methods to characterize the CR-induced changes of brain metabolic and vascular functions in aging rats. We found that old rats (24 months of age) with CR diet had reduced glucose uptake and lactate concentration, but increased ketone bodies level, compared with the age-matched and young (5 months of age) controls. The shifted metabolism was associated with preserved vascular function: old CR rats also had maintained cerebral blood flow relative to the age-matched controls. When investigating the metabolites in mitochondrial tricarboxylic acid cycle, we found that citrate and α-ketoglutarate were preserved in the old CR rats. We suggest that CR is neuroprotective; ketone bodies, cerebral blood flow, and α-ketoglutarate may play important roles in preserving brain physiology in aging. PMID:25896951

  2. Skeletal muscle PGC-1α modulates systemic ketone body homeostasis and ameliorates diabetic hyperketonemia in mice.

    PubMed

    Svensson, Kristoffer; Albert, Verena; Cardel, Bettina; Salatino, Silvia; Handschin, Christoph

    2016-05-01

    Ketone bodies (KBs) are crucial energy substrates during states of low carbohydrate availability. However, an aberrant regulation of KB homeostasis can lead to complications such as diabetic ketoacidosis. Exercise and diabetes affect systemic KB homeostasis, but the regulation of KB metabolism is still enigmatic. In our study in mice with either knockout or overexpression of the peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α in skeletal muscle, PGC-1α regulated ketolytic gene transcription in muscle. Furthermore, KB homeostasis of these mice was investigated during withholding of food, exercise, and ketogenic diet feeding, and after streptozotocin injection. In response to these ketogenic stimuli, modulation of PGC-1α levels in muscle affected systemic KB homeostasis. Moreover, the data demonstrate that skeletal muscle PGC-1α is necessary for the enhanced ketolytic capacity in response to exercise training and overexpression of PGC-1α in muscle enhances systemic ketolytic capacity and is sufficient to ameliorate diabetic hyperketonemia in mice. In cultured myotubes, the transcription factor estrogen-related receptor-α was a partner of PGC-1α in the regulation of ketolytic gene transcription. These results demonstrate a central role of skeletal muscle PGC-1α in the transcriptional regulation of systemic ketolytic capacity.-Svensson, K., Albert, V., Cardel, B., Salatino, S., Handschin, C. Skeletal muscle PGC-1α modulates systemic ketone body homeostasis and ameliorates diabetic hyperketonemia in mice. PMID:26849960

  3. Regulation of myocardial ketone body metabolism by the gut microbiota during nutrient deprivation

    PubMed Central

    Crawford, Peter A.; Crowley, Jan R.; Sambandam, Nandakumar; Muegge, Brian D.; Costello, Elizabeth K.; Hamady, Micah; Knight, Rob; Gordon, Jeffrey I.

    2009-01-01

    Studies in mice indicate that the gut microbiota promotes energy harvest and storage from components of the diet when these components are plentiful. Here we examine how the microbiota shapes host metabolic and physiologic adaptations to periods of nutrient deprivation. Germ-free (GF) mice and mice who had received a gut microbiota transplant from conventionally raised donors were compared in the fed and fasted states by using functional genomic, biochemical, and physiologic assays. A 24-h fast produces a marked change in gut microbial ecology. Short-chain fatty acids generated from microbial fermentation of available glycans are maintained at higher levels compared with GF controls. During fasting, a microbiota-dependent, Pparα-regulated increase in hepatic ketogenesis occurs, and myocardial metabolism is directed to ketone body utilization. Analyses of heart rate, hydraulic work, and output, mitochondrial morphology, number, and respiration, plus ketone body, fatty acid, and glucose oxidation in isolated perfused working hearts from GF and colonized animals (combined with in vivo assessments of myocardial physiology) revealed that the fasted GF heart is able to sustain its performance by increasing glucose utilization, but heart weight, measured echocardiographically or as wet mass and normalized to tibial length or lean body weight, is significantly reduced in both fasted and fed mice. This myocardial-mass phenotype is completely reversed in GF mice by consumption of a ketogenic diet. Together, these results illustrate benefits provided by the gut microbiota during periods of nutrient deprivation, and emphasize the importance of further exploring the relationship between gut microbes and cardiovascular health. PMID:19549860

  4. Ketone body β-hydroxybutyrate blocks the NLRP3 inflammasome-mediated inflammatory disease

    PubMed Central

    Youm, Yun-Hee; Nguyen, Kim Y.; Grant, Ryan W.; Goldberg, Emily L.; Bodogai, Monica; Kim, Dongin; D'Agostino, Dominic; Planavsky, Noah; Lupfer, Christopher; Kanneganti, Thirumala D.; Kang, Seokwon; Horvath, Tamas L.; Fahmy, Tarek M.; Crawford, Peter A.; Biragyn, Arya; Alnemri, Emad; Dixit, Vishwa Deep

    2015-01-01

    Ketone bodies , β-hydroxybutyrate (BHB) and acetoacetate support mammalian survival during states of energy deficit by serving as alternative source of ATP1. BHB levels are elevated during starvation, high-intensity exercise or by the low carbohydrate ketogenic diet2. Prolonged caloric restriction or fasting reduces inflammation as immune system adapts to low glucose supply and energy metabolism switches towards mitochondrial fatty acid oxidation, ketogenesis and ketolysis2-6. However, role of ketones bodies in regulation of innate immune response is unknown. We report that BHB, but neither acetoacetate nor structurally-related short chain fatty acids, butyrate and acetate, suppresses activation of the NLRP3 inflammasome in response to several structurally unrelated NLRP3 activators, without impacting NLRC4, AIM2 or non-canonical caspase-11 inflammasome activation. Mechanistically, BHB inhibits NLRP3 inflammasome by preventing K+ efflux and reducing ASC oligomerization and speck formation. The inhibitory effects of BHB on NLRP3 were not dependent on chirality or classical starvation regulated mechanisms like AMPK, reactive oxygen species (ROS), autophagy or glycolytic inhibition. BHB blocked NLRP3 inflammasome without undergoing oxidation in TCA cycle, independently of uncoupling protein-2 (UCP2), Sirt2, receptor Gpr109a and inhibition of NLRP3 did not correlate with magnitude of histone acetylation in macrophages. BHB reduced the NLRP3 inflammasome mediated IL-1β and IL-18 production in human monocytes. In vivo, BHB attenuates caspase-1 activation and IL-1β secretion in mouse models of NLRP3-mediated diseases like Muckle-Wells Syndrome (MWS), Familial Cold Autoinflammatory syndrome (FCAS) and urate crystal induce body cavity inflammation. Taken together, these findings suggest that the anti-inflammatory effects of caloric restriction or ketogenic diets may be mechanistically linked to BHB-mediated inhibition of the NLRP3 inflammasome, and point to the potential

  5. Ketone Body Therapy Protects From Lipotoxicity and Acute Liver Failure Upon Pparα Deficiency.

    PubMed

    Pawlak, Michal; Baugé, Eric; Lalloyer, Fanny; Lefebvre, Philippe; Staels, Bart

    2015-08-01

    Acute liver failure (ALF) is a severe and rapid liver injury, often occurring without any preexisting liver disease, which may precipitate multiorgan failure and death. ALF is often associated with impaired β-oxidation and increased oxidative stress (OS), characterized by elevated levels of hepatic reactive oxygen species (ROS) and lipid peroxidation (LPO) products. Peroxisome proliferator-activated receptor (PPAR)α has been shown to confer hepatoprotection in acute and chronic liver injury, at least in part, related to its ability to control peroxisomal and mitochondrial β-oxidation. To study the pathophysiological role of PPARα in hepatic response to high OS, we induced a pronounced LPO by treating wild-type and Pparα-deficient mice with high doses of fish oil (FO), containing n-3 polyunsaturated fatty acids. FO feeding of Pparα-deficient mice, in contrast to control sunflower oil, surprisingly induced coma and death due to ALF as indicated by elevated serum alanine aminotransferase, aspartate aminotransferase, ammonia, and a liver-specific increase of ROS and LPO-derived malondialdehyde. Reconstitution of PPARα specifically in the liver using adeno-associated serotype 8 virus-PPARα in Pparα-deficient mice restored β-oxidation and ketogenesis and protected mice from FO-induced lipotoxicity and death. Interestingly, administration of the ketone body β-hydroxybutyrate prevented FO-induced ALF in Pparα-deficient mice, and normalized liver ROS and malondialdehyde levels. Therefore, PPARα protects the liver from FO-induced OS through its regulatory actions on ketone body levels. β-Hydroxybutyrate treatment could thus be an option to prevent LPO-induced liver damage. PMID:26087172

  6. Effects of ketone bodies in Alzheimer's disease in relation to neural hypometabolism, β-amyloid toxicity, and astrocyte function.

    PubMed

    Hertz, Leif; Chen, Ye; Waagepetersen, Helle S

    2015-07-01

    Diet supplementation with ketone bodies (acetoacetate and β-hydroxybuturate) or medium-length fatty acids generating ketone bodies has consistently been found to cause modest improvement of mental function in Alzheimer's patients. It was suggested that the therapeutic effect might be more pronounced if treatment was begun at a pre-clinical stage of the disease instead of well after its manifestation. The pre-clinical stage is characterized by decade-long glucose hypometabolism in brain, but ketone body metabolism is intact even initially after disease manifestation. One reason for the impaired glucose metabolism may be early destruction of the noradrenergic brain stem nucleus, locus coeruleus, which stimulates glucose metabolism, at least in astrocytes. These glial cells are essential in Alzheimer pathogenesis. The β-amyloid peptide Aβ interferes with their cholinergic innervation, which impairs synaptic function because of diminished astrocytic glutamate release. Aβ also reduces glucose metabolism and causes hyperexcitability. Ketone bodies are similarly used against seizures, but the effectively used concentrations are so high that they must interfere with glucose metabolism and de novo synthesis of neurotransmitter glutamate, reducing neuronal glutamatergic signaling. The lower ketone body concentrations used in Alzheimer's disease may owe their effect to support of energy metabolism, but might also inhibit release of gliotransmitter glutamate. Alzheimer's disease is a panglial-neuronal disorder with long-standing brain hypometabolism, aberrations in both neuronal and astrocytic glucose metabolism, inflammation, hyperexcitability, and dementia. Relatively low doses of β-hydroxybutyrate can have an ameliorating effect on cognitive function. This could be because of metabolic supplementation or inhibition of Aβ-induced release of glutamate as gliotransmitter, which is likely to reduce hyperexcitability and inflammation. The therapeutic

  7. Ketone Bodies Mediate Anti-Seizure Effects Through Mitochondrial Permeability Transition

    PubMed Central

    Kim, Do Young; Simeone, Kristina A.; Simeone, Timothy A.; Pandya, Jignesh D.; Wilke, Julianne C.; Ahn, Younghee; Geddes, James W.; Sullivan, Patrick G.; Rho, Jong M.

    2015-01-01

    Objective Ketone bodies (KB) are products of fatty acid oxidation and serve as essential fuels during fasting or treatment with the high-fat anti-seizure ketogenic diet (KD). Despite growing evidence that KB exert broad neuroprotective effects, their role in seizure control has not been firmly demonstrated. The major goal of this study was to demonstrate the direct anti-seizure effects of KB and to identify an underlying target mechanism. Methods We studied the effects of both the KD and KB in spontaneously epileptic Kcna1-null mice using a combination of behavioral, planar multi-electrode, and standard cellular electophysiological techniques. Thresholds for mitochondrial permeability transition (mPT) were determined in acutely isolated brain mitochondria. Results KB alone were sufficient to: (1) exert anti-seizure effects in Kcna1-null mice; (2) restore intrinsic impairment of hippocampal long-term potentiation (LTP) and spatial learning-memory defects in Kcna1-null mutants; and (3) raise the threshold for calcium-induced mPT in acutely prepared mitochondria from hippocampi of Kcna1-null animals. Targeted deletion of the cyclophilin D (CypD) subunit of the mPT complex abrogated the effects of KB on mPT, and in vivo pharmacological inhibition and activation of mPT were found to mirror and reverse, respectively, the anti-seizure effects of the KD in Kcna1-null mice. Interpretation The present data reveal the first direct link between mPT and seizure control, and provide a potential mechanistic explanation for the KD. Given that mPT is increasingly being implicated in diverse neurological disorders, our results suggest that metabolism-based treatments and/or metabolic substrates might represent a worthy paradigm for therapeutic development. PMID:25899847

  8. Enzyme activities support the use of liver lipid-derived ketone bodies as aerobic fuels in muscle tissues of active sharks.

    PubMed

    Watson, R R; Dickson, K A

    2001-01-01

    Few data exist to test the hypothesis that elasmobranchs utilize ketone bodies rather than fatty acids for aerobic metabolism in muscle, especially in continuously swimming, pelagic sharks, which are expected to be more reliant on lipid fuel stores during periods between feeding bouts and due to their high aerobic metabolic rates. Therefore, to provide support for this hypothesis, biochemical indices of lipid metabolism were measured in the slow-twitch, oxidative (red) myotomal muscle, heart, and liver of several active shark species, including the endothermic shortfin mako, Isurus oxyrinchus. Tissues were assayed spectrophotometrically for indicator enzymes of fatty acid oxidation (3-hydroxy-o-acyl-CoA dehydrogenase), ketone-body catabolism (3-oxoacid-CoA transferase), and ketogenesis (hydroxy-methylglutaryl-CoA synthase). Red muscle and heart had high capacities for ketone utilization, low capacities for fatty acid oxidation, and undetectable levels of ketogenic enzymes. Liver demonstrated undetectable activities of ketone catabolic enzymes but high capacities for fatty acid oxidation and ketogenesis. Serum concentrations of the ketone beta-hydroxybutyrate varied interspecifically (means of 0.128-0.978 micromol mL(-1)) but were higher than levels previously reported for teleosts. These results are consistent with the hypothesis that aerobic metabolism in muscle tissue of active sharks utilizes ketone bodies, and not fatty acids, derived from liver lipid stores. PMID:11247746

  9. Raspberry Ketone

    MedlinePlus

    Raspberry ketone is a chemical from red raspberries, as well as kiwifruit, peaches, grapes, apples, other berries, vegetables such as rhubarb, and the bark of yew, maple, and pine trees. People take raspberry ketone by mouth for ...

  10. Enhancement of L-3-hydroxybutyryl-CoA dehydrogenase activity and circulating ketone body levels by pantethine. Relevance to dopaminergic injury

    PubMed Central

    2010-01-01

    Background The administration of the ketone bodies hydroxybutyrate and acetoacetate is known to exert a protective effect against metabolic disorders associated with cerebral pathologies. This suggests that the enhancement of their endogenous production might be a rational therapeutic approach. Ketone bodies are generated by fatty acid beta-oxidation, a process involving a mitochondrial oxido-reductase superfamily, with fatty acid-CoA thioesters as substrates. In this report, emphasis is on the penultimate step of the process, i.e. L-3-hydroxybutyryl-CoA dehydrogenase activity. We determined changes in enzyme activity and in circulating ketone body levels in the MPTP mouse model of Parkinson's disease. Since the active moiety of CoA is pantetheine, mice were treated with pantethine, its naturally-occurring form. Pantethine has the advantage of being known as an anti-inflammatory and hypolipidemic agent with very few side effects. Results We found that dehydrogenase activity and circulating ketone body levels were drastically reduced by the neurotoxin MPTP, whereas treatment with pantethine overcame these adverse effects. Pantethine prevented dopaminergic neuron loss and motility disorders. In vivo and in vitro experiments showed that the protection was associated with enhancement of glutathione (GSH) production as well as restoration of respiratory chain complex I activity and mitochondrial ATP levels. Remarkably, pantethine treatment boosted the circulating ketone body levels in MPTP-intoxicated mice, but not in normal animals. Conclusions These finding demonstrate the feasibility of the enhancement of endogenous ketone body production and provide a promising therapeutic approach to Parkinson's disease as well as, conceivably, to other neurodegenerative disorders. PMID:20416081

  11. Medium-chain fatty acids inhibit mitochondrial metabolism in astrocytes promoting astrocyte-neuron lactate and ketone body shuttle systems.

    PubMed

    Thevenet, Jonathan; De Marchi, Umberto; Domingo, Jaime Santo; Christinat, Nicolas; Bultot, Laurent; Lefebvre, Gregory; Sakamoto, Kei; Descombes, Patrick; Masoodi, Mojgan; Wiederkehr, Andreas

    2016-05-01

    Medium-chain triglycerides have been used as part of a ketogenic diet effective in reducing epileptic episodes. The health benefits of the derived medium-chain fatty acids (MCFAs) are thought to result from the stimulation of liver ketogenesis providing fuel for the brain. We tested whether MCFAs have direct effects on energy metabolism in induced pluripotent stem cell-derived human astrocytes and neurons. Using single-cell imaging, we observed an acute pronounced reduction of the mitochondrial electrical potential and a concomitant drop of the NAD(P)H signal in astrocytes, but not in neurons. Despite the observed effects on mitochondrial function, MCFAs did not lower intracellular ATP levels or activate the energy sensor AMP-activated protein kinase. ATP concentrations in astrocytes were unaltered, even when blocking the respiratory chain, suggesting compensation through accelerated glycolysis. The MCFA decanoic acid (300 μM) promoted glycolysis and augmented lactate formation by 49.6%. The shorter fatty acid octanoic acid (300 μM) did not affect glycolysis but increased the rates of astrocyte ketogenesis 2.17-fold compared with that of control cells. MCFAs may have brain health benefits through the modulation of astrocyte metabolism leading to activation of shuttle systems that provide fuel to neighboring neurons in the form of lactate and ketone bodies.-Thevenet, J., De Marchi, U., Santo Domingo, J., Christinat, N., Bultot, L., Lefebvre, G., Sakamoto, K., Descombes, P., Masoodi, M., Wiederkehr, A. Medium-chain fatty acids inhibit mitochondrial metabolism in astrocytes promoting astrocyte-neuron lactate and ketone body shuttle systems. PMID:26839375

  12. Early Energetic Particle Irradiation of the HED Parent Body Regolith

    NASA Technical Reports Server (NTRS)

    Bogard, D. D.; Garrison, D. H.; Rao, M. N.

    1996-01-01

    Previous studies have shown that many individual grains within the dark phase of the Kapoeta howardite were irradiated with energetic particles while residing on the surface of the early HED regolith. Particle tracks in these grains vary in density by more than an order of magnitude and undoubtedly were formed by energetic heavy (Fe) ions associated with early solar flares. Early Irradiation of HED Regolith: Concentrations of excess Ne alone are not sufficient to decide between competing galactic and solar irradiation models. However, from recent studies of depth samples of oriented lunar rocks, we have shown that the cosmogenic 21-Ne/22-Ne ratio produced in feldspar differs substantially between Galactic Cosmic Radiation (GCR) and solar protons, and that this difference is exactly that predicted from cross-section data. Using Ne literature data and new isotopic data we obtained on acid-etched, separated feldspar from both the light and dark phases of Kapoeta, we derive 21-Ne/22-Ne = 0.80 for the recent GCR irradiation and 21-Ne/22-Ne = 0.68 for the early regolith irradiation. This derived ratio indicates that the early Ne production in the regolith occurred by both galactic and solar protons. If we adopt a likely one-component regolith model in which all grains were exposed to galactic protons but individual grains had variable exposure to solar protons, we estimate that this early GCR irradiation lasted for about 3-6 m.y. More complex two-component regolith models involving separate solar and galactic irradiation would permit this GCR age to be longer. Higher-energy solar protons would permit the GCR to be longer. Higher-energy solar protons would permit the GCR age to be shorter. Further, cosmogenic 126(Xe) in Kapoeta dark is no more than a factor of about 2 higher than that observed in Kapoeta light. Because 126(Xe) can only be formed by galactic protons and not solar protons, these data support a short GCR irradiation for the HED regolith. This would also be

  13. Effect of the Ketone Body Beta-Hydroxybutyrate on the Innate Defense Capability of Primary Bovine Mammary Epithelial Cells

    PubMed Central

    Flinspach, Claudia; Pfaffl, Michael W.; Kliem, Heike

    2016-01-01

    Negative energy balance and ketosis are thought to cause impaired immune function and to increase the risk of clinical mastitis in dairy cows. The present in vitro study aimed to investigate the effect of elevated levels of the predominant ketone body β-hydroxybutyrate on the innate defense capability of primary bovine mammary epithelial cells (pbMEC) challenged with the mastitis pathogen Escherichia coli (E. coli). Therefore, pbMEC of healthy dairy cows in mid- lactation were isolated from milk and challenged in culture with 3 mM BHBA and E. coli. pbMEC stimulated with E. coli for 6 h or 30 h showed an up-regulation of several innate immune genes, whereas co-stimulation of pbMEC with 3 mM BHBA and E. coli resulted in the down-regulation of CCL2, SAA3, LF and C3 gene expression compared to the challenge with solely the bacterial stimulus. These results indicated that increased BHBA concentrations may be partially responsible for the higher mastitis susceptibility of dairy cows in early lactation. Elevated levels of BHBA in blood and milk during negative energy balance and ketosis are likely to impair innate immune function in the bovine mammary gland by attenuating the expression of a broad range of innate immune genes. PMID:27310007

  14. Raspberry Ketone

    MedlinePlus

    Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely ... keep in mind that there is no reliable scientific evidence that raspberry ketone improves weight loss when ...

  15. Metabolism of glucose, glutamine, long-chain fatty acids and ketone bodies by murine macrophages.

    PubMed Central

    Newsholme, P; Curi, R; Gordon, S; Newsholme, E A

    1986-01-01

    Maximum activities of some key enzymes of metabolism were studied in elicited (inflammatory) macrophages of the mouse and lymph-node lymphocytes of the rat. The activity of hexokinase in the macrophage is very high, as high as that in any other major tissue of the body, and higher than that of phosphorylase or 6-phosphofructokinase, suggesting that glucose is a more important fuel than glycogen and that the pentose phosphate pathway is also important in these cells. The latter suggestion is supported by the high activities of both glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. However, the rate of glucose utilization by 'resting' macrophages incubated in vitro is less than the 10% of the activity of 6-phosphofructokinase: this suggests that the rate of glycolysis is increased dramatically during phagocytosis or increased secretory activity. The macrophages possess higher activities of citrate synthase and oxoglutarate dehydrogenase than do lymphocytes, suggesting that the tricarboxylic acid cycle may be important in energy generation in these cells. The activity of 3-oxoacid CoA-transferase is higher in the macrophage, but that of 3-hydroxybutyrate dehydrogenase is very much lower than those in the lymphocytes. The activity of carnitine palmitoyltransferase is higher in macrophages, suggesting that fatty acids as well as acetoacetate could provide acetyl-CoA as substrate for the tricarboxylic acid cycle. No detectable rate of acetoacetate or 3-hydroxybutyrate utilization was observed during incubation of resting macrophages, but that of oleate was 1.0 nmol/h per mg of protein or about 2.2% of the activity of palmitoyltransferase. The activity of glutaminase is about 4-fold higher in macrophages than in lymphocytes, which suggests that the rate of glutamine utilization could be very high. The rate of utilization of glutamine by resting incubated macrophages was similar to that reported for rat lymphocytes, but was considerably lower than the

  16. BDNF mediates adaptive brain and body responses to energetic challenges.

    PubMed

    Marosi, Krisztina; Mattson, Mark P

    2014-02-01

    Emerging findings suggest that brain-derived neurotrophic factor (BDNF) serves widespread roles in regulating energy homeostasis by controlling patterns of feeding and physical activity, and by modulating glucose metabolism in peripheral tissues. BDNF mediates the beneficial effects of energetic challenges such as vigorous exercise and fasting on cognition, mood, cardiovascular function, and on peripheral metabolism. By stimulating glucose transport and mitochondrial biogenesis BDNF bolsters cellular bioenergetics and protects neurons against injury and disease. By acting in the brain and periphery, BDNF increases insulin sensitivity and parasympathetic tone. Genetic factors, a 'couch potato' lifestyle, and chronic stress impair BDNF signaling, and this may contribute to the pathogenesis of metabolic syndrome. Novel BDNF-focused interventions are being developed for obesity, diabetes, and neurological disorders. PMID:24361004

  17. Hyperinsulinemia shifted energy supply from glucose to ketone bodies in early nonalcoholic steatohepatitis from high-fat high-sucrose diet induced Bama minipigs.

    PubMed

    Yang, Shu-lin; Xia, Ji-han; Zhang, Yuan-yuan; Fan, Jian-gao; Wang, Hua; Yuan, Jing; Zhao, Zhan-zhao; Pan, Qin; Mu, Yu-lian; Xin, Lei-lei; Chen, Yao-xing; Li, Kui

    2015-01-01

    The minipig can serve as a good pharmacological model for human subjects. However, the long-term pathogenesis of high-calorie diet-induced metabolic syndromes, including NASH, has not been well described in minipigs. We examined the development of metabolic syndromes in Bama minipigs that were fed a high-fat, high-sucrose diet (HFHSD) for 23 months, by using histology and serum biochemistry and by profiling the gene expression patterns in the livers of HFHSD pigs compared to controls. The pathology findings revealed microvesicular steatosis, iron overload, arachidonic acid synthesis, lipid peroxidation, reduced antioxidant capacity, increased cellular damage, and inflammation in the liver. RNA-seq analysis revealed that 164 genes were differentially expressed between the livers of the HFHSD and control groups. The pathogenesis of early-stage NASH was characterized by hyperinsulinemia and by de novo synthesis of fatty acids and nascent triglycerides, which were deposited as lipid droplets in hepatocytes. Hyperinsulinemia shifted the energy supply from glucose to ketone bodies, and the high ketone body concentration induced the overexpression of cytochrome P450 2E1 (CYP2E1). The iron overload, CYP2E1 and alcohol dehydrogenase 4 overexpression promoted reactive oxygen species (ROS) production, which resulted in arachidonic and linoleic acid peroxidation and, in turn, led to malondialdehyde production and a cellular response to ROS-mediated DNA damage. PMID:26358367

  18. Hyperinsulinemia shifted energy supply from glucose to ketone bodies in early nonalcoholic steatohepatitis from high-fat high-sucrose diet induced Bama minipigs

    PubMed Central

    Yang, Shu-lin; Xia, Ji-han; Zhang, Yuan-yuan; Fan, Jian-gao; Wang, Hua; Yuan, Jing; Zhao, Zhan-zhao; Pan, Qin; Mu, Yu-lian; Xin, Lei-lei; Chen, Yao-xing; Li, Kui

    2015-01-01

    The minipig can serve as a good pharmacological model for human subjects. However, the long-term pathogenesis of high-calorie diet-induced metabolic syndromes, including NASH, has not been well described in minipigs. We examined the development of metabolic syndromes in Bama minipigs that were fed a high-fat, high-sucrose diet (HFHSD) for 23 months, by using histology and serum biochemistry and by profiling the gene expression patterns in the livers of HFHSD pigs compared to controls. The pathology findings revealed microvesicular steatosis, iron overload, arachidonic acid synthesis, lipid peroxidation, reduced antioxidant capacity, increased cellular damage, and inflammation in the liver. RNA-seq analysis revealed that 164 genes were differentially expressed between the livers of the HFHSD and control groups. The pathogenesis of early-stage NASH was characterized by hyperinsulinemia and by de novo synthesis of fatty acids and nascent triglycerides, which were deposited as lipid droplets in hepatocytes. Hyperinsulinemia shifted the energy supply from glucose to ketone bodies, and the high ketone body concentration induced the overexpression of cytochrome P450 2E1 (CYP2E1). The iron overload, CYP2E1 and alcohol dehydrogenase 4 overexpression promoted reactive oxygen species (ROS) production, which resulted in arachidonic and linoleic acid peroxidation and, in turn, led to malondialdehyde production and a cellular response to ROS-mediated DNA damage. PMID:26358367

  19. Vanadate treatment restores the expression of genes for key enzymes in the glucose and ketone bodies metabolism in the liver of diabetic rats.

    PubMed Central

    Valera, A; Rodriguez-Gil, J E; Bosch, F

    1993-01-01

    Oral administration of vanadate to diabetic streptozotocin-treated rats decreased the high blood glucose and D-3-hydroxybutyrate levels related to diabetes. The increase in the expression of the P-enolpyruvate carboxykinase (PEPCK) gene, the main regulatory enzyme of gluconeogenesis, was counteracted in the liver and the kidney after vanadate administration to diabetic rats. Vanadate also counteracted the induction in tyrosine aminotransferase gene expression due to diabetes and was able to increase the expression of the glucokinase gene to levels even higher than those found in healthy animals. Similarly, an induction in pyruvate kinase mRNA transcripts was observed in diabetic vanadate-treated rats. These effects were correlated with changes on glucokinase and pyruvate kinase activities. Vanadate treatment caused a decrease in the expression of the liver-specific glucose transporter, GLUT-2. Thus, vanadate was able to restore liver glucose utilization and block glucose production in diabetic rats. The increase in the expression of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCoAS) gene, the key regulatory enzyme in the ketone bodies production pathway, observed in diabetic rats was also blocked by vanadate. Furthermore, a similar pattern in the expression of PEPCK, GLUT-2, HMGCoAS, and the transcription factor CCAAT/enhancer-binding protein alpha genes has been observed. All of these results suggest that the regulation of the expression of genes involved in the glucose and ketone bodies metabolism could be a key step in the normalization process induced by vanadate administration to diabetic rats. Images PMID:8100835

  20. Fueling Performance: Ketones Enter the Mix.

    PubMed

    Egan, Brendan; D'Agostino, Dominic P

    2016-09-13

    Ketone body metabolites serve as alternative energy substrates during prolonged fasting, calorie restriction, or reduced carbohydrate (CHO) availability. Using a ketone ester supplement, Cox et al. (2016) demonstrate that acute nutritional ketosis alters substrate utilization patterns during exercise, reduces lactate production, and improves time-trial performance in elite cyclists. PMID:27626197

  1. Body cooling and its energetic implications for feeding and diving of tufted ducks.

    PubMed

    de Leeuw, J J; Butler, P J; Woakes, A J; Zegwaard, F

    1998-01-01

    Wintering in a temperate climate with low water temperatures is energetically expensive for diving ducks. The energy costs associated with body cooling due to diving and ingesting large amounts of cold food were measured in tufted ducks (Aythya fuligula) feeding on zebra mussels (Dreissena polymorpha), using implanted heart rate and body temperature transmitters. The effects of diving depth and food ingestion were measured in two sets of experiments: we measured body cooling and energy costs of six tufted ducks diving to different depths in a 6-m-deep indoor tank; the costs for food ingestion and crushing mussel shells were assessed under seminatural winter conditions with the same ducks feeding on mussels in a 1.5-m-deep outdoor pond. Body temperature dropped during feeding bouts and increased gradually during intermittent resting periods. The temperature drop increased linearly with dive duration. The rate of body cooling increased with feeding depth, but it was lower again at depths below 4 m. Half of the increment in energy costs of diving can be attributed to thermoregulatory heat production, of which approximately 50% is generated after diving to warm up the body. The excess costs for ducks feeding on large-sized mussels could be entirely explained by the estimated energy cost necessary to compensate the heat loss following food ingestion, suggesting that the heat production from shell crushing substituted for thermoregulation. Recovery from heat loss is probably a major component of the activity budget of wintering diving ducks. PMID:9798260

  2. First-principles energetics of water clusters and ice: A many-body analysis

    SciTech Connect

    Gillan, M. J.; Alfè, D.; Bartók, A. P.; Csányi, G.

    2013-12-28

    Standard forms of density-functional theory (DFT) have good predictive power for many materials, but are not yet fully satisfactory for cluster, solid, and liquid forms of water. Recent work has stressed the importance of DFT errors in describing dispersion, but we note that errors in other parts of the energy may also contribute. We obtain information about the nature of DFT errors by using a many-body separation of the total energy into its 1-body, 2-body, and beyond-2-body components to analyze the deficiencies of the popular PBE and BLYP approximations for the energetics of water clusters and ice structures. The errors of these approximations are computed by using accurate benchmark energies from the coupled-cluster technique of molecular quantum chemistry and from quantum Monte Carlo calculations. The systems studied are isomers of the water hexamer cluster, the crystal structures Ih, II, XV, and VIII of ice, and two clusters extracted from ice VIII. For the binding energies of these systems, we use the machine-learning technique of Gaussian Approximation Potentials to correct successively for 1-body and 2-body errors of the DFT approximations. We find that even after correction for these errors, substantial beyond-2-body errors remain. The characteristics of the 2-body and beyond-2-body errors of PBE are completely different from those of BLYP, but the errors of both approximations disfavor the close approach of non-hydrogen-bonded monomers. We note the possible relevance of our findings to the understanding of liquid water.

  3. First-principles energetics of water clusters and ice: A many-body analysis

    NASA Astrophysics Data System (ADS)

    Gillan, M. J.; Alfè, D.; Bartók, A. P.; Csányi, G.

    2013-12-01

    Standard forms of density-functional theory (DFT) have good predictive power for many materials, but are not yet fully satisfactory for cluster, solid, and liquid forms of water. Recent work has stressed the importance of DFT errors in describing dispersion, but we note that errors in other parts of the energy may also contribute. We obtain information about the nature of DFT errors by using a many-body separation of the total energy into its 1-body, 2-body, and beyond-2-body components to analyze the deficiencies of the popular PBE and BLYP approximations for the energetics of water clusters and ice structures. The errors of these approximations are computed by using accurate benchmark energies from the coupled-cluster technique of molecular quantum chemistry and from quantum Monte Carlo calculations. The systems studied are isomers of the water hexamer cluster, the crystal structures Ih, II, XV, and VIII of ice, and two clusters extracted from ice VIII. For the binding energies of these systems, we use the machine-learning technique of Gaussian Approximation Potentials to correct successively for 1-body and 2-body errors of the DFT approximations. We find that even after correction for these errors, substantial beyond-2-body errors remain. The characteristics of the 2-body and beyond-2-body errors of PBE are completely different from those of BLYP, but the errors of both approximations disfavor the close approach of non-hydrogen-bonded monomers. We note the possible relevance of our findings to the understanding of liquid water.

  4. Longer Food Chains in Pelagic Ecosystems: Trophic Energetics of Animal Body Size and Metabolic Efficiency.

    PubMed

    McGarvey, Richard; Dowling, Natalie; Cohen, Joel E

    2016-07-01

    Factors constraining the structure of food webs can be investigated by comparing classes of ecosystems. We find that pelagic ecosystems, those based on one-celled primary producers, have longer food chains than terrestrial ecosystems. Yet pelagic ecosystems have lower primary productivity, contrary to the hypothesis that greater energy flows permit higher trophic levels. We hypothesize that longer food chain length in pelagic ecosystems, compared with terrestrial ecosystems, is associated with smaller pelagic animal body size permitting more rapid trophic energy transfer. Assuming negative allometric dependence of biomass production rate on body mass at each trophic level, the lowest three pelagic animal trophic levels are estimated to add biomass more rapidly than their terrestrial counterparts by factors of 12, 4.8, and 2.6. Pelagic animals consequently transport primary production to a fifth trophic level 50-190 times more rapidly than animals in terrestrial webs. This difference overcomes the approximately fivefold slower pelagic basal productivity, energetically explaining longer pelagic food chains. In addition, ectotherms, dominant at lower pelagic animal trophic levels, have high metabolic efficiency, also favoring higher rates of trophic energy transfer in pelagic ecosystems. These two animal trophic flow mechanisms imply longer pelagic food chains, reestablishing an important role for energetics in food web structure. PMID:27322123

  5. Fatty Acid Transport Protein 1 (FATP1) Localizes in Mitochondria in Mouse Skeletal Muscle and Regulates Lipid and Ketone Body Disposal

    PubMed Central

    Guitart, Maria; Osorio-Conles, Óscar; Pentinat, Thais; Cebrià, Judith; García-Villoria, Judit; Sala, David; Sebastián, David; Zorzano, Antonio; Ribes, Antonia; Jiménez-Chillarón, Josep C.; García-Martínez, Celia; Gómez-Foix, Anna M.

    2014-01-01

    , likely secondary to the sparing of ketone body oxidation by the enhanced oxidation of fatty acids. PMID:24858472

  6. The Ketone Body, β-Hydroxybutyrate Stimulates the Autophagic Flux and Prevents Neuronal Death Induced by Glucose Deprivation in Cortical Cultured Neurons.

    PubMed

    Camberos-Luna, Lucy; Gerónimo-Olvera, Cristian; Montiel, Teresa; Rincon-Heredia, Ruth; Massieu, Lourdes

    2016-03-01

    Glucose is the major energy substrate in brain, however, during ketogenesis induced by starvation or prolonged hypoglycemia, the ketone bodies (KB), acetoacetate and β-hydroxybutyrate (BHB) can substitute for glucose. KB improve neuronal survival in diverse injury models, but the mechanisms by which KB prevent neuronal damage are still not well understood. In the present study we have investigated whether protection by the D isomer of BHB (D-BHB) against neuronal death induced by glucose deprivation (GD), is related to autophagy. Autophagy is a lysosomal-dependent degradation process activated during nutritional stress, which leads to the digestion of damaged proteins and organelles providing energy for cell survival. Results show that autophagy is activated in cortical cultured neurons during GD, as indicated by the increase in the levels of the lipidated form of the microtubule associated protein light chain 3 (LC3-II), and the number of autophagic vesicles. At early phases of glucose reintroduction (GR), the levels of p62 declined suggesting that the degradation of the autophagolysosomal content takes place at this time. In cultures exposed to GD and GR in the presence of D-BHB, the levels of LC3-II and p62 rapidly declined and remained low during GR, suggesting that the KB stimulates the autophagic flux preventing autophagosome accumulation and improving neuronal survival. PMID:26303508

  7. Short communication: ketone body concentration in milk determined by Fourier transform infrared spectroscopy: value for the detection of hyperketonemia in dairy cows.

    PubMed

    van Knegsel, A T M; van der Drift, S G A; Horneman, M; de Roos, A P W; Kemp, B; Graat, E A M

    2010-07-01

    The objective of this study was to evaluate Fourier transform infrared (FTIR) spectrometry to measure milk ketone bodies to detect hyperketonemic cows and compare this method with milk fat to protein ratio to detect hyperketonemia. Plasma and milk samples were obtained weekly from calving to wk 9 postpartum from 69 high-producing dairy cows. The reference test for hyperketonemia was defined as plasma concentration of beta-hydroxybutyrate (BHBA) >or=1,200 micromol/L. The weekly prevalence of hyperketonemia during the first 9 wk of lactation was, on average, 7.1%. Both BHBA and acetone in milk, determined by FTIR, had a higher sensitivity (80%) to detect hyperketonemia compared with milk fat to protein ratio (66%). Specificity was similar for the 3 diagnostic tests (71, 70, and 71%). In conclusion, FTIR predictions of BHBA or acetone in milk can detect cows with hyperketonemia in early lactation with a higher accuracy compared with the use of milk fat to protein ratio. Because of the high proportion of false-positive tests, there are concerns about the practical applicability of FTIR predictions of acetone, BHBA, and fat to protein ratio in milk to detect hyperketonemic cows. PMID:20630223

  8. A SNP in the 3'-untranslated region of AMPKγ1 may associate with serum ketone body and milk production of Holstein dairy cows.

    PubMed

    Mahmoudi, Ahmad; Zargaran, Amir; Amini, Hamid-Reza; Assadi, Assad; Vajdi Hokmabad, Reza; Eghbalsaied, Shahin

    2015-12-10

    AMPK is the key switch for providing the energy balance between cellular anabolic and catabolic processes. In this study, we aimed to screen the PRKAG1 (AMPKγ1) gene in high, moderate, and low producing Holstein dairy cows. A sample of 100 pregnant dairy cows, comprising 41 high, 33 moderate, and 26 low milk yields were selected from three large dairy herds in Isfahan province of Iran. Body condition score (BCS) was estimated before parturition while beta hydroxyl butyric acid (BHBA) as a measure of ketone bodies was measured at the fifth day postpartum. In addition, using three primer pairs covering exons 2-11 and 3'-UTR of the PRKAG1 gene, a random sample of 10 high milk yield dairy cows were amplified and sequenced. The sequencing results showed the presence of a T12571C mutation in intron 6 and a T14280C mutation in the 3'-untranslated region (UTR) of the PRKAG1 gene. Following a PCR reaction for amplification of the 3'-UTR amplicons, single strand conformation polymorphism (SSCP) assay was implemented for discrimination of the mutation in the studied population. Then, we evaluated if the mutation associates with the BCS, serum BHBA level, and production traits. The experimental analysis showed that the mutated allele significantly increased the BHBA level, BCS, as well as milk and protein yield. Bioinformatic study revealed that this 3'-UTR mutation distorts the target site of mir-423-5p microRNA which is one of the most highly expressed microRNAs in the bovine mammary gland, liver, and kidney. Given the role of AMPK in energy metabolism, the newly identified 3'-UTR mutation highlights the importance of AMPK and suggests a role of miRNAs for regulation of cellular metabolism, metabolism disorders, and production traits in Holstein dairy cows. PMID:26226224

  9. Impact of Universal Plasma and Energetic Particle Processes on Icy Bodies of the Kuiper Belt and the Oort Cloud

    NASA Technical Reports Server (NTRS)

    Cooper, John F.; Richardson, J. D.; Hill, M. E.; Sturner, S. J.

    2008-01-01

    Modeling of space plasma and energetic particle interactions with icy bodies of the outer solar system is simplified when there is commonality of the underlying source, acceleration, and transport processes in spatially distinct regions from the supersonic heliosphere through the heliosheath into the local interstellar medium (LISM). Current trends in the Voyager heliosheath measurements suggest strong commonality to processes in the LISM. The Fisk-Gloeckler "universal" spectrum at suprathermal energies apparently plays a strong role in coupling the plasma and high energy particle regimes in the spatial and energetic transitions from the outer heliosphere to the LISM. Dominant processes in consecutive energy regimes project to varying effects versus irradiation depth on exposed upper surfaces of airless small icy bodies and to upper atmospheres of larger bodies such as Titan and Pluto. Relative absence of the universal suprathermal spectrum in the mid-heliospheric region of the classical Kuiper Belt may profoundly affect surface color diversity of icy bodies in this region.

  10. Muscle mechanical work requirements during normal walking: the energetic cost of raising the body's center-of-mass is significant.

    PubMed

    Neptune, R R; Zajac, F E; Kautz, S A

    2004-06-01

    Inverted pendulum models of walking predict that little muscle work is required for the exchange of body potential and kinetic energy in single-limb support. External power during walking (product of the measured ground reaction force and body center-of-mass (COM) velocity) is often analyzed to deduce net work output or mechanical energetic cost by muscles. Based on external power analyses and inverted pendulum theory, it has been suggested that a primary mechanical energetic cost may be associated with the mechanical work required to redirect the COM motion at the step-to-step transition. However, these models do not capture the multi-muscle, multi-segmental properties of walking, co-excitation of muscles to coordinate segmental energetic flow, and simultaneous production of positive and negative muscle work. In this study, a muscle-actuated forward dynamic simulation of walking was used to assess whether: (1). potential and kinetic energy of the body are exchanged with little muscle work; (2). external mechanical power can estimate the mechanical energetic cost for muscles; and (3.) the net work output and the mechanical energetic cost for muscles occurs mostly in double support. We found that the net work output by muscles cannot be estimated from external power and was the highest when the COM moved upward in early single-limb support even though kinetic and potential energy were exchanged, and muscle mechanical (and most likely metabolic) energetic cost is dominated not only by the need to redirect the COM in double support but also by the need to raise the COM in single support. PMID:15111069

  11. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) test system is a device intended to identify ketones in urine and other body fluids. Identification of... Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... acidity of body fluids) or ketosis (a condition characterized by increased production of ketone...

  12. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) test system is a device intended to identify ketones in urine and other body fluids. Identification of... Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... acidity of body fluids) or ketosis (a condition characterized by increased production of ketone...

  13. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) test system is a device intended to identify ketones in urine and other body fluids. Identification of... Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... acidity of body fluids) or ketosis (a condition characterized by increased production of ketone...

  14. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) test system is a device intended to identify ketones in urine and other body fluids. Identification of... Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... acidity of body fluids) or ketosis (a condition characterized by increased production of ketone...

  15. "Body-In-The-Loop": Optimizing Device Parameters Using Measures of Instantaneous Energetic Cost

    PubMed Central

    Felt, Wyatt; Selinger, Jessica C.; Donelan, J. Maxwell; Remy, C. David

    2015-01-01

    This paper demonstrates methods for the online optimization of assistive robotic devices such as powered prostheses, orthoses and exoskeletons. Our algorithms estimate the value of a physiological objective in real-time (with a body “in-the-loop”) and use this information to identify optimal device parameters. To handle sensor data that are noisy and dynamically delayed, we rely on a combination of dynamic estimation and response surface identification. We evaluated three algorithms (Steady-State Cost Mapping, Instantaneous Cost Mapping, and Instantaneous Cost Gradient Search) with eight healthy human subjects. Steady-State Cost Mapping is an established technique that fits a cubic polynomial to averages of steady-state measures at different parameter settings. The optimal parameter value is determined from the polynomial fit. Using a continuous sweep over a range of parameters and taking into account measurement dynamics, Instantaneous Cost Mapping identifies a cubic polynomial more quickly. Instantaneous Cost Gradient Search uses a similar technique to iteratively approach the optimal parameter value using estimates of the local gradient. To evaluate these methods in a simple and repeatable way, we prescribed step frequency via a metronome and optimized this frequency to minimize metabolic energetic cost. This use of step frequency allows a comparison of our results to established techniques and enables others to replicate our methods. Our results show that all three methods achieve similar accuracy in estimating optimal step frequency. For all methods, the average error between the predicted minima and the subjects’ preferred step frequencies was less than 1% with a standard deviation between 4% and 5%. Using Instantaneous Cost Mapping, we were able to reduce subject walking-time from over an hour to less than 10 minutes. While, for a single parameter, the Instantaneous Cost Gradient Search is not much faster than Steady-State Cost Mapping, the

  16. Ketone ester effects on metabolism and transcription

    PubMed Central

    Veech, Richard L.

    2014-01-01

    Ketosis induced by starvation or feeding a ketogenic diet has widespread and often contradictory effects due to the simultaneous elevation of both ketone bodies and free fatty acids. The elevation of ketone bodies increases the energy of ATP hydrolysis by reducing the mitochondrial NAD couple and oxidizing the coenzyme Q couple, thus increasing the redox span between site I and site II. In contrast, metabolism of fatty acids leads to a reduction of both mitochondrial NAD and mitochondrial coenzyme Q causing a decrease in the ΔG of ATP hydrolysis. In contrast, feeding ketone body esters leads to pure ketosis, unaccompanied by elevation of free fatty acids, producing a physiological state not previously seen in nature. The effects of pure ketosis on transcription and upon certain neurodegenerative diseases make approach not only interesting, but of potential therapeutic value. PMID:24714648

  17. Multi-body forces and the energetics of transition metals, alloys, and semiconductors

    SciTech Connect

    Carlsson, A.E.

    1992-01-01

    Progress over the past year is divided into 3 areas: potential-energy functions for transition-metal aluminides; electronic structure and energetics of complex structures and quasicrystals; and ceramic materials (PdO, PtO).

  18. A high-resolution thermoelectric module-based calorimeter for measuring the energetics of isolated ventricular trabeculae at body temperature.

    PubMed

    Johnston, Callum M; Han, June-Chiew; Ruddy, Bryan P; Nielsen, Poul M F; Taberner, Andrew J

    2015-07-15

    Isolated ventricular trabeculae are the most common experimental preparations used in the study of cardiac energetics. However, the experiments have been conducted at subphysiological temperatures. We have overcome this limitation by designing and constructing a novel calorimeter with sufficiently high thermal resolution for simultaneously measuring the heat output and force production of isolated, contracting, ventricular trabeculae at body temperature. This development was largely motivated by the need to better understand cardiac energetics by performing such measurements at body temperature to relate tissue performance to whole heart behavior in vivo. Our approach uses solid-state thermoelectric modules, tailored for both temperature sensing and temperature control. The thermoelectric modules have high sensitivity and low noise, which, when coupled with a multilevel temperature control system, enable an exceptionally high temperature resolution with a noise-equivalent power an order of magnitude greater than those of other existing muscle calorimeters. Our system allows us to rapidly and easily change the experimental temperature without disturbing the state of the muscle. Our calorimeter is useful in many experiments that explore the energetics of normal physiology as well as pathophysiology of cardiac muscle. PMID:26001412

  19. Methyl isobutyl ketone (MIBK)

    Integrated Risk Information System (IRIS)

    Methyl Isobutyl Ketone ( MIBK ) ; CASRN 108 - 10 - 1 ; Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for

  20. Methyl ethyl ketone (MEK)

    Integrated Risk Information System (IRIS)

    Methyl ethyl ketone ( MEK ) ( CASRN 78 - 93 - 3 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonc

  1. Effects of increased mechanical work by isolated perfused rat heart during production or uptake of ketone bodies. Assessment of mitochondrial oxidized to reduced free nicotinamide-adenine dinucleotide ratios and oxaloacetate concentrations.

    PubMed Central

    Opie, L H; Owen, P

    1975-01-01

    Metabolic effects of increased mechanical work were studied by comparing isolated pumping rat hearts perfused by the atrial-filling technique with aortic-perfused non-pumping hearts perfused by the technique of Langendorff. The initial medium usually contained glucose (11 mm) and palmitate (0.6 mm bound to 0.1 mm albumin). During increased heart work (comparing pumping with non-pumping hearts) the uptake of oxygen and glucose increased threefold, but that of free fatty acids was unchanged. Tissue contents of alpha-oxoglutarate, NH4+, malate, lactate, pyruvate and Pi rose with increased heart work, but contents of ATP, phosphocreatine and citrate fell. Ketone bodies were produced with a ratio of beta-hydroxybutyrate/acetoacetate of about 3:1 in both pumping and non-pumping hearts but with higher net production rates in non-pumping hearts. When ketone bodies were added in relatively high concentrations (total 4 mm) to a glucose (11 mm) medium the medium, ratios of beta-hydroxybutyrate/acetoacetate were not steady even after 60 min of perfusion. The validity of calculating mitochondrial free NAD+/NADH ratios from the tissue contents of the reactants of the glutamate dehydrogenase system or the beta-hydroxybutyrate dehydrogenase system is assessed. The activities of these enzymes are considerably less in the rat heart than in the rat liver, introducing reservations into the application to the heart of the principles used by Williamson et al. (1967) for calculation of mitochondrial free NAD+/NADH ratios of liver mitochondria... PMID:173281

  2. Anabolic implant effects on visceral organ mass, chemical body composition, and estimated energetic efficiency in cloned (genetically identical) beef steers.

    PubMed

    Hutcheson, J P; Johnson, D E; Gerken, C L; Morgan, J B; Tatum, J D

    1997-10-01

    Six sets of four genetically identical Brangus steers (n = 24; X BW 409 kg) were used to determine the effect of different anabolic implants on visceral organ mass, chemical body composition, estimated tissue deposition, and energetic efficiency. Steers within a clone set were randomly assigned to one of the following implant treatments: C, no implant; E, estrogenic; A, androgenic, or AE, androgenic + estrogenic. Steers were slaughtered 112 d after implanting; visceral organs were weighed and final body composition determined by mechanical grinding and chemical analysis of the empty body. Mass of the empty gastrointestinal tract (GIT) was reduced approximately 9% (P < .10) in steers implanted with estrogen alone or in combination with an androgen. Liver mass was increased (P < .10) from 6 to 14% by implants. Steers implanted with the AE combination had greater (P < .10) daily protein accretion (163.4 g/d) than either E (128.8 g/d) or A (137.1 g/d), and, because the combination improved gain above C (101.1 g/d), this demonstrates the additive effects of a combination implant on protein deposition. Anabolic implants did not alter (P > .10) the efficiency of ME utilization. In general, estrogenic implants decreased GIT, androgenic implants increased liver, and all implants increased hide mass. Steers implanted with an AE combination had additive effects on protein deposition compared with either implant alone. The NEg requirements for body gain are estimated to be reduced 19% by estrogenic or combination implants. PMID:9331863

  3. The effect of rearing temperature on development, body size, energetics and fecundity of the diamondback moth.

    PubMed

    Garrad, R; Booth, D T; Furlong, M J

    2016-04-01

    Temperature is arguably the most important abiotic factor influencing the life history of ectotherms. It limits survival and affects all physiological and metabolic processes, including energy and nutrient procurement and processing, development and growth rates, locomotion ability and ultimately reproductive success. However, the influence of temperature on the energetic cost of development has not been thoroughly investigated. We show that in the diamondback moth [Plutella xylostella L. (Lepidoptera: Plutellidae)] rearing temperature (range 10-30°C) affected growth and development rates, the energetic cost of development and fecundity. Rearing at lower temperatures increased development times and slowed growth rate, but resulted in larger adult mass. Fecundity was lowest at 10°C, highest at 15°C and intermediate at temperatures of 20°C and above. At a given rearing temperature fecundity was correlated with pupal mass and most eggs were laid on the first day of oviposition, there was no correlation between total eggs laid and adult longevity. The highest production cost was incurred at 10°C; this decreased with increasing temperature, was minimized in the range 20-25°C, and then increased again at 30°C. These minimized production costs occurred at temperatures close to the intrinsic optimum temperature for this species and may reflect the rearing temperature for optimal fitness. Thus at sub-optimal temperatures greater food resources are required during the development period. Predicted increased temperatures at the margins of the current core distribution of P. xylostella could ameliorate current seasonal effects on fecundity, thereby increasing the probability of winter survival leading to more resilient range expansion and an increased probability of pest outbreaks. PMID:26696587

  4. Reduction of Energetic Demands through Modification of Body Size and Routine Metabolic Rates in Extremophile Fish.

    PubMed

    Passow, Courtney N; Greenway, Ryan; Arias-Rodriguez, Lenin; Jeyasingh, Punidan D; Tobler, Michael

    2015-01-01

    Variation in energy availability or maintenance costs in extreme environments can exert selection for efficient energy use, and reductions in organismal energy demand can be achieved in two ways: reducing body mass or metabolic suppression. Whether long-term exposure to extreme environmental conditions drives adaptive shifts in body mass or metabolic rates remains an open question. We studied body size variation and variation in routine metabolic rates in locally adapted populations of extremophile fish (Poecilia mexicana) living in toxic, hydrogen sulfide-rich springs and caves. We quantified size distributions and routine metabolic rates in wild-caught individuals from four habitat types. Compared with ancestral populations in nonsulfidic surface habitats, extremophile populations were characterized by significant reductions in body size. Despite elevated metabolic rates in cave fish, the body size reduction precipitated in significantly reduced energy demands in all extremophile populations. Laboratory experiments on common garden-raised fish indicated that elevated routine metabolic rates in cave fish likely have a genetic basis. The results of this study indicate that adaptation to extreme environments directly impacts energy metabolism, with fish living in cave and sulfide spring environments expending less energy overall during routine metabolism. PMID:26052634

  5. Utility of ketone measurement in the prevention, diagnosis and management of diabetic ketoacidosis.

    PubMed

    Misra, S; Oliver, N S

    2015-01-01

    Ketone measurement is advocated for the diagnosis of diabetic ketoacidosis and assessment of its severity. Assessing the evidence base for ketone measurement in clinical practice is challenging because multiple methods are available but there is a lack of consensus about which is preferable. Evaluating the utility of ketone measurement is additionally problematic because of variability in the biochemical definition of ketoacidosis internationally and in the proposed thresholds for ketone measures. This has led to conflicting guidance from expert bodies on how ketone measurement should be used in the management of ketoacidosis. The development of point-of-care devices that can reliably measure the capillary blood ketone β-hydroxybutyrate (BOHB) has widened the spectrum of applications of ketone measurement, but whether the evidence base supporting these applications is robust enough to warrant their incorporation into routine clinical practice remains unclear. The imprecision of capillary blood ketone measures at higher values, the lack of availability of routine laboratory-based assays for BOHB and the continued cost-effectiveness of urine ketone assessment prompt further discussion on the role of capillary blood ketone assessment in ketoacidosis. In the present article, we review the various existing methods of ketone measurement, the precision of capillary blood ketone as compared with other measures, its diagnostic accuracy in predicting ketoacidosis and other clinical applications including prevention, assessment of severity and resolution of ketoacidosis. PMID:25307274

  6. The Effects of Prosthesis Inertial Properties on Prosthetic Knee Moment and Hip Energetics Required to Achieve Able-Bodied Kinematics.

    PubMed

    Narang, Yashraj S; Arelekatti, V N Murthy; Winter, Amos G

    2016-07-01

    There is a major need in the developing world for a low-cost prosthetic knee that enables users to walk with able-bodied kinematics and low energy expenditure. To efficiently design such a knee, the relationship between the inertial properties of a prosthetic leg and joint kinetics and energetics must be determined. In this paper, using inverse dynamics, the theoretical effects of varying the inertial properties of an above-knee prosthesis on the prosthetic knee moment, hip power, and absolute hip work required for walking with able-bodied kinematics were quantified. The effects of independently varying mass and moment of inertia of the prosthesis, as well as independently varying the masses of each prosthesis segment, were also compared. Decreasing prosthesis mass to 25% of physiological leg mass increased peak late-stance knee moment by 43% and decreased peak swing knee moment by 76%. In addition, it reduced peak stance hip power by 26%, average swing hip power by 76%, and absolute hip work by 22%. Decreasing upper leg mass to 25% of its physiological value reduced absolute hip work by just 2%, whereas decreasing lower leg and foot mass reduced work by up to 22%, with foot mass having the greater effect. Results are reported in the form of parametric illustrations that can be utilized by researchers, designers, and prosthetists. The methods and outcomes presented have the potential to improve prosthetic knee component selection, facilitate able-bodied kinematics, and reduce energy expenditure for users of low-cost, passive knees in developing countries, as well as for users of advanced active knees in developed countries. PMID:26186794

  7. Space Weathering of airless bodies in the Solar System - Combining hypervelocity dust impacts with energetic irradiation experiments

    NASA Astrophysics Data System (ADS)

    Fiege, K.; Bennett, C.; Guglielmino, M.; Orlando, T. M.; Trieloff, M.; Srama, R.

    2015-12-01

    The chemical and mineralogical characterization of meteorites and their parent asteroids provides us with information about the processes and conditions during the formation of the inner Solar System. However, linking meteorites to their parent bodies is problematic. Astronomical observations aim to reconstruct the surface properties of these bodies primarily by visible and infrared spectra, but space weathering severely modifies the optical, compositional and physical properties of thin surface layers and thus precludes proper identification of chemistry and mineralogy. The effects of space weathering have been experimentally studied mainly with respect to ion bombardment and sputtering. Other studies aimed to simulate the influence of micrometeoroid bombardment by using laser ablation techniques. However, there is sufficient evidence that laser ablation does not realistically lead to the same effects as produced during real micrometeorite impacts. We performed micrometeorite bombardment using a 2MV dust accelerator at the Institute for Space Systems at University of Stuttgart, Germany, capable of generating impact speeds up to 100 km s-1. These results are combined with energetic irradiation experiments at the Electron and Photon Induced Chemistry on Surfaces (EPICS) laboratory at Georgia Institute of Technology, USA. By simulating highly realistic irradiation conditions, we are able to investigate the processes of particle and solar wind irradiation on solid planetary surfaces and study the formation of e.g., nanophase iron in minerals, the effects on hydrous minerals regarding their volatile budgets, or possible OH-formation in nominally anhydrous minerals and relate these to their optical properties. Using a variety of minerals, this work aims to contribute to a better understanding of the general alteration mechanisms in space environments in dependence of weathering agent and available material. We here present the results of initial comparison analysis and

  8. Energetics of median and paired fin swimming, body and caudal fin swimming, and gait transition in parrotfish (Scarus schlegeli) and triggerfish (Rhinecanthus aculeatus).

    PubMed

    Korsmeyer, Keith E; Steffensen, John Fleng; Herskin, Jannik

    2002-05-01

    To determine the energetic costs of rigid-body, median or paired-fin (MPF) swimming versus undulatory, body-caudal fin (BCF) swimming, we measured oxygen consumption as a function of swimming speed in two MPF swimming specialists, Schlegel's parrotfish and Picasso triggerfish. The parrotfish swam exclusively with the pectoral fins at prolonged swimming speeds up to 3.2 total lengths per second (L s(-1); 30 min critical swimming speed, U(crit)). At higher speeds, gait transferred to a burst-and-coast BCF swimming mode that resulted in rapid fatigue. The triggerfish swam using undulations of the soft dorsal and anal fins up to 1.5 L s(-1), beyond which BCF undulations were recruited intermittently. BCF swimming was used continuously above 3.5 L s(-1), and was accompanied by synchronous undulations of the dorsal and anal fins. The triggerfish were capable of high, prolonged swimming speeds of up to 4.1 L s(-1) (30 min U(crit)). In both species, the rates of increase in oxygen consumption with swimming speed were higher during BCF swimming than during rigid-body MPF swimming. Our results indicate that, for these species, undulatory swimming is energetically more costly than rigid-body swimming, and therefore support the hypothesis that MPF swimming is more efficient. In addition, use of the BCF gait at higher swimming speed increased the cost of transport in both species beyond that predicted for MPF swimming at the same speeds. This suggests that, unlike for terrestrial locomotion, gait transition in fishes does not occur to reduce energetic costs, but to increase recruitable muscle mass and propulsive surfaces. The appropriate use of the power and exponential functions to model swimming energetics is also discussed. PMID:11948202

  9. Multi-body forces and the energetics of transition metals, alloys, and semiconductors. Annual progress report, (1991--1992)

    SciTech Connect

    Carlsson, A.E.

    1992-11-01

    Progress over the past year is divided into 3 areas: potential-energy functions for transition-metal aluminides; electronic structure and energetics of complex structures and quasicrystals; and ceramic materials (PdO, PtO).

  10. Green organocatalytic α-hydroxylation of ketones.

    PubMed

    Voutyritsa, Errika; Theodorou, Alexis; Kokotos, Christoforos G

    2016-06-28

    An efficient and green method for the α-hydroxylation of substituted ketones has been developed. This method includes the in situ conversion of various ketones into the corresponding silyl enol ethers and their oxidation to the corresponding α-hydroxy ketones. Two protocols have been established leading either to protected α-hydroxy carbonyls or free α-hydroxy ketones. Both procedures are easy to follow and lead to good to high yields for a variety of ketones. PMID:26867154

  11. Cerebral metabolic adaptation and ketone metabolism after brain injury

    PubMed Central

    Prins, Mayumi L

    2010-01-01

    The developing central nervous system has the capacity to metabolize ketone bodies. It was once accepted that on weaning, the ‘post-weaned/adult’ brain was limited solely to glucose metabolism. However, increasing evidence from conditions of inadequate glucose availability or increased energy demands has shown that the adult brain is not static in its fuel options. The objective of this review is to summarize the body of literature specifically regarding cerebral ketone metabolism at different ages, under conditions of starvation and after various pathologic conditions. The evidence presented supports the following findings: (1) there is an inverse relationship between age and the brain’s capacity for ketone metabolism that continues well after weaning; (2) neuroprotective potentials of ketone administration have been shown for neurodegenerative conditions, epilepsy, hypoxia/ischemia, and traumatic brain injury; and (3) there is an age-related therapeutic potential for ketone as an alternative substrate. The concept of cerebral metabolic adaptation under various physiologic and pathologic conditions is not new, but it has taken the contribution of numerous studies over many years to break the previously accepted dogma of cerebral metabolism. Our emerging understanding of cerebral metabolism is far more complex than could have been imagined. It is clear that in addition to glucose, other substrates must be considered along with fuel interactions, metabolic challenges, and cerebral maturation. PMID:17684514

  12. Preliminary study to compare body residues and sublethal energetic responses in benthic invertebrates exposed to sediment-bound 2,4,5-trichlorophenol

    SciTech Connect

    Penttinen, O.P.; Kukkonen, J.; Pellinen, J.

    1996-02-01

    Relationships between concentration of 2,4,5-trichlorophenol (TCP) in sediment, body residues of the chemical, and sublethal biological effects in three benthic invertebrates were studied. Uncontaminated lake sediment was spiked with four concentrations (23--85 {micro}g/g dry sediment) of TCP. Chironomid larvae (Chironomus riparius), oligochaete worms (Lumbriculus variegatus), and sphaeriid bivalves (Sphaerium corneum) were exposed to the sediment. The effect of chlorophenol on the rate of heat dissipation of animals was monitored by direct microcalorimetry. It appeared that both the behavior of the animals and their body residues explained the energetic response. Valve closure behavior of S. corneum reduced the accumulation of toxicant (< 0.3 {micro}mol/g) but was observed as a complex energetic response. Heat dissipation of L. variegatus was at the same level in control animals and those with high body residues of TCP (> 1.5 {micro}mol/g). Regardless of the amount of TCP accumulated to C. riparius (0.1--0.6 {micro}mol/g), the rate of heat dissipation was almost two times higher than that of the control animals, probably reflecting uncoupling of oxidative phosphorylation, which is the primary mode of toxic action of chlorophenols. However, when a threshold concentration was exceeded there was no concentration-response dependence until acute toxicity appears.

  13. Male Snakes Allocate Time and Energy according to Individual Energetic Status: Body Condition, Steroid Hormones, and Reproductive Behavior in Timber Rattlesnakes, Crotalus horridus.

    PubMed

    Lind, Craig M; Beaupre, Steven J

    2015-01-01

    Life-history theory predicts that organisms will hedge current reproductive investment against potential costs in terms of survivorship and future fecundity. However, little is known regarding the endocrine mechanisms underlying bet-hedging strategies in free-ranging male vertebrates. We examined the relationships among individual energetic status, steroid hormones, mate search, and reproductive behavior in free-ranging male timber rattlesnakes. Snakes were monitored over four active seasons in order to test two hypotheses: (1) males adjust the amount of time and energy allocated toward reproduction according to the level of individual energy stores, and (2) observed condition-dependent reproductive allocation is associated with circulating concentrations of steroid hormones (testosterone and corticosterone) thought to regulate reproductive behaviors in vertebrates. A positive relationship between body condition and testosterone was observed in both the field and the laboratory. Male mate search effort was positively correlated with both body condition and testosterone. Body condition and testosterone concentrations were negatively related to time allocated toward foraging during the breeding season. A strong effect of year was observed in the analysis of testosterone and search effort, suggesting that multiple environmental factors impact hormone production and reproductive investment. Corticosterone was not related to any measured variable. Therefore, our results did not indicate a clear role of corticosterone in mediating observed relationships between energetic status and behavior. Observed relationships are consistent with the hypothesis that males allocate time and energy toward reproduction according to individual energetic status and that testosterone plays a role in mediating the trade-off between current reproductive investment and residual reproductive value. PMID:26658410

  14. Centrarchid Energetics

    SciTech Connect

    Bevelhimer, Mark S; Breck, Dr. James

    2009-06-01

    This chapter contains sections titled: (1) Introduction; (2) Centrarchid bioenergetics models; (3) Food consumption and feeding energetics; (4) Metabolic rate; (5) Energetic wastes (egestion, excretion, and SDA); (6) Growth energetics; (7) Reproductive energetics; (8) Synthesis; (9) Research needs; and (10) References.

  15. Stereoselective titanium-mediated aldol reactions of a chiral lactate-derived ethyl ketone with ketones.

    PubMed

    Alcoberro, Sandra; Gómez-Palomino, Alejandro; Solà, Ricard; Romea, Pedro; Urpí, Fèlix; Font-Bardia, Mercè

    2014-01-17

    Aldol reactions of titanium enolates of lactate-derived ethyl ketone 1 with other ketones proceed in a very efficient and stereocontrolled manner provided that a further equivalent of TiCl4 is added to the reacting mixture. The scope of these reactions encompasses simple ketones such as acetone or cyclohexanone as well as other ketones that contain potential chelating groups such as pyruvate esters or α- and β-hydroxy ketones. PMID:24372372

  16. A mathematical high bar-human body model for analysing and interpreting mechanical-energetic processes on the high bar.

    PubMed

    Arampatzis, A; Brüggemann, G P

    1998-12-01

    The aims of this study were: 1. To study the transfer of energy between the high bar and the gymnast. 2. To develop criteria from the utilisation of high bar elasticity and the utilisation of muscle capacity to assess the effectiveness of a movement solution. 3. To study the influence of varying segment movement upon release parameters. For these purposes a model of the human body attached to the high bar (high bar-human body model) was developed. The human body was modelled using a 15-segment body system. The joint-beam element method (superelement) was employed for modelling the high bar. A superelement consists of four rigid segments connected by joints (two Cardan joints and one rotational-translational joint) and springs (seven rotation springs and one tension-compression spring). The high bar was modelled using three superelements. The input data required for the high bar human body model were collected with video-kinematographic (50 Hz) and dynamometric (500 Hz) techniques. Masses and moments of inertia of the 15 segments were calculated using the data from the Zatsiorsky et al. (1984) model. There are two major phases characteristic of the giant swing prior to dismounts from the high bar. In the first phase the gymnast attempts to supply energy to the high bar-humanbody system through muscle activity and to store this energy in the high bar. The difference between the energy transferred to the high bar and the reduction in the total energy of the body could be adopted as a criterion for the utilisation of high bar elasticity. The energy previously transferred into the high bar is returned to the body during the second phase. An advantageous increase in total body energy at the end of the exercise could only be obtained through muscle energy supply. An index characterising the utilisation of muscle capacity was developed out of the difference between the increase in total body energy and the energy returned from the high bar. A delayed and initially slow but

  17. EXTRACTION OF TETRAVALENT PLUTONIUM VALUES WITH METHYL ETHYL KETONE, METHYL ISOBUTYL KETONE ACETOPHENONE OR MENTHONE

    DOEpatents

    Seaborg, G.T.

    1961-08-01

    A process is described for extracting tetravalent plutonium from an aqueous acid solution with methyl ethyl ketone, methyl isobutyl ketone, or acetophenone and with the extraction of either tetravalent or hexavalent plutonium into menthone. (AEC)

  18. The water hexamer: Three-body interactions, structures, energetics, and OH-stretch spectroscopy at finite temperature

    NASA Astrophysics Data System (ADS)

    Tainter, C. J.; Skinner, J. L.

    2012-09-01

    Using a newly developed and recently parameterized classical empirical simulation model for water that involves explicit three-body interactions, we determine the eleven most stable isomers of the water hexamer. We find that the lowest energy isomer is one of the cage structures, in agreement with far-IR and microwave experiments. The energy ordering for the binding energies is cage > glove > book > bag > chair > boat > chaise, and energies relative to the cage are in good agreement with CCSD(T) calculations. The three-body contributions to the cage, book, and chair are also in reasonable agreement with CCSD(T) results. The energy of each isomer results from a delicate balance involving the number of hydrogen bonds, the strain of these hydrogen bonds, and cooperative and anti-cooperative three-body interactions, whose contribution we can understand simply from the form of the three-body interactions in the simulation model. Oxygen-oxygen distances in the cage and book isomers are in good agreement with microwave experiments. Hydrogen-bond distances depend on both donor and acceptor, which can again be understood from the three-body model. Fully anharmonic OH-stretch spectra are calculated for these low-energy structures, and compared with shifted harmonic results from ab initio and density functional theory calculations. Replica-exchange molecular dynamics simulations were performed from 40 to 194 K, which show that the cage isomer has the lowest free energy from 0 to 70 K, and the book isomer has the lowest free energy from 70 to 194 K. OH-stretch spectra were calculated between 40 and 194 K, and results at 40, 63, and 79 K were compared to recent experiments, leading to re-assignment of the peaks in the experimental spectra. We calculate local OH-stretch cumulative spectral densities for different donor-acceptor types and compare to analogous results for liquid water.

  19. The water hexamer: three-body interactions, structures, energetics, and OH-stretch spectroscopy at finite temperature.

    PubMed

    Tainter, C J; Skinner, J L

    2012-09-14

    Using a newly developed and recently parameterized classical empirical simulation model for water that involves explicit three-body interactions, we determine the eleven most stable isomers of the water hexamer. We find that the lowest energy isomer is one of the cage structures, in agreement with far-IR and microwave experiments. The energy ordering for the binding energies is cage > glove > book > bag > chair > boat > chaise, and energies relative to the cage are in good agreement with CCSD(T) calculations. The three-body contributions to the cage, book, and chair are also in reasonable agreement with CCSD(T) results. The energy of each isomer results from a delicate balance involving the number of hydrogen bonds, the strain of these hydrogen bonds, and cooperative and anti-cooperative three-body interactions, whose contribution we can understand simply from the form of the three-body interactions in the simulation model. Oxygen-oxygen distances in the cage and book isomers are in good agreement with microwave experiments. Hydrogen-bond distances depend on both donor and acceptor, which can again be understood from the three-body model. Fully anharmonic OH-stretch spectra are calculated for these low-energy structures, and compared with shifted harmonic results from ab initio and density functional theory calculations. Replica-exchange molecular dynamics simulations were performed from 40 to 194 K, which show that the cage isomer has the lowest free energy from 0 to 70 K, and the book isomer has the lowest free energy from 70 to 194 K. OH-stretch spectra were calculated between 40 and 194 K, and results at 40, 63, and 79 K were compared to recent experiments, leading to re-assignment of the peaks in the experimental spectra. We calculate local OH-stretch cumulative spectral densities for different donor-acceptor types and compare to analogous results for liquid water. PMID:22979856

  20. Breath Ketone Testing: A New Biomarker for Diagnosis and Therapeutic Monitoring of Diabetic Ketosis

    PubMed Central

    Qiao, Yue; Gao, Zhaohua; Liu, Yong; Cheng, Yan; Yu, Mengxiao; Zhao, Lingling

    2014-01-01

    Background. Acetone, β-hydroxybutyric acid, and acetoacetic acid are three types of ketone body that may be found in the breath, blood, and urine. Detecting altered concentrations of ketones in the breath, blood, and urine is crucial for the diagnosis and treatment of diabetic ketosis. The aim of this study was to evaluate the advantages of different detection methods for ketones, and to establish whether detection of the concentration of ketones in the breath is an effective and practical technique. Methods. We measured the concentrations of acetone in the breath using gas chromatography-mass spectrometry and β-hydroxybutyrate in fingertip blood collected from 99 patients with diabetes assigned to groups 1 (−), 2 (±), 3 (+), 4 (++), or 5 (+++) according to urinary ketone concentrations. Results. There were strong relationships between fasting blood glucose, age, and diabetic ketosis. Exhaled acetone concentration significantly correlated with concentrations of fasting blood glucose, ketones in the blood and urine, LDL-C, creatinine, and blood urea nitrogen. Conclusions. Breath testing for ketones has a high sensitivity and specificity and appears to be a noninvasive, convenient, and repeatable method for the diagnosis and therapeutic monitoring of diabetic ketosis. PMID:24900994

  1. Mild electrophilic trifluoromethylthiolation of ketones with trifluoromethanesulfanamide.

    PubMed

    Wu, Wei; Zhang, Xuxue; Liang, Fang; Cao, Song

    2015-07-01

    A straightforward and convenient approach for trifluoromethylthiolation of various acyclic and cyclic ketones with PhNHSCF3 is described. The reaction proceeds smoothly in the presence of acetyl chloride at room temperature and affords α-trifluoromethylthiolated ketones in fair to good yields. PMID:26030292

  2. Impaired control of body cooling during heterothermia represents the major energetic constraint in an aging non-human primate exposed to cold.

    PubMed

    Terrien, Jeremy; Zahariev, Alexandre; Blanc, Stephane; Aujard, Fabienne

    2009-01-01

    Daily heterothermia is used by small mammals for energy and water savings, and seems to be preferentially exhibited during winter rather than during summer. This feature induces a trade-off between the energy saved during daily heterothermia and the energy cost of arousal, which can impact energy balance and survival under harsh environmental conditions. Especially, aging may significantly affect such trade off during cold-induced energy stress, but direct evidences are still lacking. We hypothesized that aging could alter the energetics of daily heterothermia, and that the effects could differ according to season. In the gray mouse lemur (Microcebus murinus), a non-human primate species which exhibits daily heterothermia, we investigated the effects of exposures to 25 and 12 degrees C on body composition, energy balance, patterns of heterothermia and water turnover in adult (N = 8) and aged animals (N = 7) acclimated to winter-like or summer-like photoperiods. Acclimation to summer prevented animals from deep heterothermia, even during aging. During winter, adult animals at 12 degrees C and aged animals at 25 degrees C exhibited low levels of energy expenditure with minor modulations of heterothermia. The major effects of cold were observed during winter, and were particularly pronounced in aged mouse lemurs which exhibited deep heterothermia phases. Body composition was not significantly affected by age and could not explain the age-related differences in heterothermia patterns. However, aging was associated with increased levels of energy expenditure during cold exposure, in concomitance with impaired energy balance. Interestingly, increased energy expenditure and depth of heterothermia phases were strongly correlated. In conclusion, it appeared that the exhibition of shallow heterothermia allowed energy savings during winter in adult animals only. Aged animals exhibited deep heterothermia and increased levels of energy expenditure, impairing energy balance

  3. Ketones block amyloid entry and improve cognition in an Alzheimer's model.

    PubMed

    Yin, Jun Xiang; Maalouf, Marwan; Han, Pengcheng; Zhao, Minglei; Gao, Ming; Dharshaun, Turner; Ryan, Christopher; Whitelegge, Julian; Wu, Jie; Eisenberg, David; Reiman, Eric M; Schweizer, Felix E; Shi, Jiong

    2016-03-01

    Sporadic Alzheimer's disease (AD) is responsible for 60%-80% of dementia cases, and the most opportune time for preventive intervention is in the earliest stage of its preclinical phase. As traditional mitochondrial energy substrates, ketone bodies (ketones, for short), beta-hydroxybutyrate, and acetoacetate, have been reported to provide symptomatic improvement and disease-modifying activity in epilepsy and neurodegenerative disorders. Recently, ketones are thought as more than just metabolites and also as endogenous factors protecting against AD. In this study, we discovered a novel neuroprotective mechanism of ketones in which they blocked amyloid-β 42, a pathologic hallmark protein of AD, entry into neurons. The suppression of intracellular amyloid-β 42 accumulation rescued mitochondrial complex I activity, reduced oxidative stress, and improved synaptic plasticity. Most importantly, we show that peripheral administration of ketones significantly reduced amyloid burden and greatly improved learning and memory ability in a symptomatic mouse model of AD. These observations provide us insights to understand and to establish a novel therapeutic use of ketones in AD prevention. PMID:26923399

  4. Energetic composites

    DOEpatents

    Danen, Wayne C.; Martin, Joe A.

    1993-01-01

    A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application.

  5. Energetic composites

    DOEpatents

    Danen, W.C.; Martin, J.A.

    1993-11-30

    A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application. 3 figures.

  6. Microbial production of natural raspberry ketone.

    PubMed

    Beekwilder, Jules; van der Meer, Ingrid M; Sibbesen, Ole; Broekgaarden, Mans; Qvist, Ingmar; Mikkelsen, Joern D; Hall, Robert D

    2007-10-01

    Raspberry ketone is an important compound for the flavour industry. It is frequently used in products such as soft drinks, sweets, puddings and ice creams. The compound can be produced by organic synthesis. Demand for "natural" raspberry ketone is growing considerably. However, this product is extremely expensive. Consequently, there is a remaining desire to better understand how raspberry ketone is synthesized in vivo, and which genes and enzymes are involved. With this information we will then be in a better position to design alternative production strategies such as microbial fermentation. This article focuses on the identification and application of genes potentially linked to raspberry ketone synthesis. We have isolated candidate genes from both raspberry and other plants, and these have been introduced into bacterial and yeast expression systems. Conditions have been determined that result in significant levels of raspberry ketone, up to 5 mg/L. These results therefore lay a strong foundation for a potentially renewable source of "natural" flavour compounds making use of plant genes. PMID:17722151

  7. Stereoselective Formation of Fully Substituted Ketone Enolates.

    PubMed

    Haimov, Elvira; Nairoukh, Zackaria; Shterenberg, Alexander; Berkovitz, Tiran; Jamison, Timothy F; Marek, Ilan

    2016-04-25

    The application of stereochemically defined acyclic fully substituted enolates of ketones to the enantioselective synthesis of quaternary carbon stereocenters would be highly valuable. Herein, we describe an approach leading to the formation of several new stereogenic centers through a combined metalation-addition of a carbonyl-carbamoyl transfer to reveal in situ stereodefined α,α-disubstituted enolates of ketone as a single stereoisomer. This approach could produce a series of aldol and Mannich products from enol carbamate with excellent diastereomeric ratios. PMID:27027778

  8. The Conversion of Carboxylic Acids to Ketones: A Repeated Discovery

    ERIC Educational Resources Information Center

    Nicholson, John W.; Wilson, Alan D.

    2004-01-01

    The conversion of carboxylic acids to ketones is a useful chemical transformation with a long history. Several chemists have claimed that they discovered the conversion of carboxylic acids to ketones yet in fact the reaction is actually known for centuries.

  9. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to...

  10. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to...

  11. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to...

  12. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to...

  13. Nickel catalyzed α-arylation of ketones with aryltrimethylammonium triflates.

    PubMed

    Li, Jing; Wang, Zhong-Xia

    2016-08-21

    Nickel-catalyzed α-arylation of ketones involving aromatic C-N cleavage has been accomplished. Intermolecular coupling of aromatic ketones with a variety of aryltrimethylammonium triflates was achieved in the presence of Ni(COD)2, IPr·HCl, and LiOBu(t), giving α-arylated ketones in reasonable to excellent yields. PMID:27443786

  14. Vapor pressures and gas-film coefficients for ketones

    USGS Publications Warehouse

    Rathbun, R.E.; Tai, D.Y.

    1987-01-01

    Comparison of handbook vapor pressures for seven ketones with more recent literature data showed large differences for four of the ketones. Gas-film coefficients for the volatilization of these ketones from water determined by two different methods were in reasonable agreement. ?? 1987.

  15. Relaxation behavior in model compounds of poly(aryl-ether-ketone-ketone) as revealed by dielectric spectroscopy

    NASA Astrophysics Data System (ADS)

    Ezquerra, T. A.; Zolotukhin, M.; Privalko, V. P.; Baltá-Calleja, F. J.; Nequlqueo, G.; García, C.; de la Campa, J. G.; de Abajo, J.

    1999-05-01

    The relaxation behavior of a series of ether-ketone oligomers, considered as model compounds of poly(ether-ketone-ketone), was studied by means of dielectric spectroscopy. The dynamics of the α relaxation of ether-ketone model compounds as compared with that of poly(arylether-ketone-ketone) (PEKK) (50/50), shows up differences which can be attributed to the variation of inter- and intramolecular correlations with the chain length. Model compounds exhibit a nearly similar degree of cooperativity regardless the differences in Tg values. The PEKK (50/50) polymer exhibits stronger cooperativity than the oligomers suggesting that in poly(ether-ketone-ketone)s molecular motions above Tg extend to more than one monomeric unit.

  16. Energetic powder

    DOEpatents

    Jorgensen, Betty S.; Danen, Wayne C.

    2003-12-23

    Fluoroalkylsilane-coated metal particles. The particles have a central metal core, a buffer layer surrounding the core, and a fluoroalkylsilane layer attached to the buffer layer. The particles may be prepared by combining a chemically reactive fluoroalkylsilane compound with an oxide coated metal particle having a hydroxylated surface. The resulting fluoroalkylsilane layer that coats the particles provides them with excellent resistance to aging. The particles can be blended with oxidant particles to form energetic powder that releases chemical energy when the buffer layer is physically disrupted so that the reductant metal core can react with the oxidant.

  17. Fatty acid-induced astrocyte ketone production and the control of food intake.

    PubMed

    Le Foll, Christelle; Levin, Barry E

    2016-06-01

    Obesity and Type 2 diabetes are major worldwide public health issues today. A relationship between total fat intake and obesity has been found. In addition, the mechanisms of long-term and excessive high-fat diet (HFD) intake in the development of obesity still need to be elucidated. The ventromedial hypothalamus (VMH) is a major site involved in the regulation of glucose and energy homeostasis where "metabolic sensing neurons" integrate metabolic signals from the periphery. Among these signals, fatty acids (FA) modulate the activity of VMH neurons using the FA translocator/CD36, which plays a critical role in the regulation of energy and glucose homeostasis. During low-fat diet (LFD) intake, FA are oxidized by VMH astrocytes to fuel their ongoing metabolic needs. However, HFD intake causes VMH astrocytes to use FA to generate ketone bodies. We postulate that these astrocyte-derived ketone bodies are exported to neurons where they produce excess ATP and reactive oxygen species, which override CD36-mediated FA sensing and act as a signal to decrease short-term food intake. On a HFD, VMH astrocyte-produced ketones reduce elevated caloric intake to LFD levels after 3 days in rats genetically predisposed to resist (DR) diet-induced obesity (DIO), but not leptin-resistant DIO rats. This suggests that, while VMH ketone production on a HFD can contribute to protection from obesity, the inherent leptin resistance overrides this inhibitory action of ketone bodies on food intake. Thus, astrocytes and neurons form a tight metabolic unit that is able to monitor circulating nutrients to alter food intake and energy homeostasis. PMID:27122369

  18. Nile Red Detection of Bacterial Hydrocarbons and Ketones in a High-Throughput Format

    SciTech Connect

    Pinzon, NM; Aukema, KG; Gralnick, JA; Wackett, LP

    2011-06-28

    A method for use in high-throughput screening of bacteria for the production of long-chain hydrocarbons and ketones by monitoring fluorescent light emission in the presence of Nile red is described. Nile red has previously been used to screen for polyhydroxybutyrate (PHB) and fatty acid esters, but this is the first report of screening for recombinant bacteria making hydrocarbons or ketones. The microtiter plate assay was evaluated using wild-type and recombinant strains of Shewanella oneidensis and Escherichia coli expressing the enzyme OleA, previously shown to initiate hydrocarbon biosynthesis. The strains expressing exogenous Stenotrophomonas maltophilia oleA, with increased levels of ketone production as determined by gas chromatography-mass spectrometry, were distinguished with Nile red fluorescence. Confocal microscopy images of S. oneidensis oleA-expressing strains stained with Nile red were consistent with a membrane localization of the ketones. This differed from Nile red staining of bacterial PHB or algal lipid droplets that showed intracellular inclusion bodies. These results demonstrated the applicability of Nile red in a high-throughput technique for the detection of bacterial hydrocarbons and ketones. IMPORTANCE In recent years, there has been renewed interest in advanced biofuel sources such as bacterial hydrocarbon production. Previous studies used solvent extraction of bacterial cultures followed by gas chromatography-mass spectrometry (GC-MS) to detect and quantify ketones and hydrocarbons (Beller HR, Goh EB, Keasling JD, Appl. Environ. Microbiol. 76: 1212-1223, 2010; Sukovich DJ, Seffernick JL, Richman JE, Gralnick JA, Wackett LP, Appl. Environ. Microbiol. 76: 3850-3862, 2010). While these analyses are powerful and accurate, their labor-intensive nature makes them intractable to high-throughput screening; therefore, methods for rapid identification of bacterial strains that are overproducing hydrocarbons are needed. The use of high

  19. Synthesis and characterization of poly(ether ketone)s containing phosphorus and fluorine

    SciTech Connect

    Youngman, P.W.; Fitch, J.W.; Cassidy, P.E. |

    1996-10-01

    Because of the excellent properties exhibited by fluorinated poly(ether ketone)s, modifications were sought to further improve this polymer toward atomic oxygen resistance. For this purpose a phosphorous-containing monomer [bis(4-fluorophenyl)phenyl phosphine oxide] was synthesized and incorporated into a poly(ether ketone) backbone by reaction with 2,2-bis[4-(4-fluorobenzoyl)phenyl]hexafluoropropane in varying proportions with bisphenol AF to produce polymers with different amounts of the phosphine oxide repeating unit in the backbone. Colorless, film-forming materials were produced with a slight increase in Tg due to the phosphine oxide function. The incorporation of this moiety also resulted in a very small increase in the dielectric constant and an improved resistance to atomic oxygen ablation.

  20. Wild Skylarks Seasonally Modulate Energy Budgets but Maintain Energetically Costly Inflammatory Immune Responses throughout the Annual Cycle

    PubMed Central

    Hegemann, Arne; Matson, Kevin D.; Versteegh, Maaike A.; Tieleman, B. Irene

    2012-01-01

    A central hypothesis of ecological immunology is that immune defences are traded off against competing physiological and behavioural processes. During energetically demanding periods, birds are predicted to switch from expensive inflammatory responses to less costly immune responses. Acute phase responses (APRs) are a particularly costly form of immune defence, and, hence, seasonal modulations in APRs are expected. Yet, hypotheses about APR modulation remain untested in free-living organisms throughout a complete annual cycle. We studied seasonal modulations in the APRs and in the energy budgets of skylarks Alauda arvensis, a partial migrant bird from temperate zones that experiences substantial ecological changes during its annual cycle. We characterized throughout the annual cycle changes in their energy budgets by measuring basal metabolic rate (BMR) and body mass. We quantified APRs by measuring the effects of a lipopolysaccharide injection on metabolic rate, body mass, body temperature, and concentrations of glucose and ketone. Body mass and BMR were lowest during breeding, highest during winter and intermediate during spring migration, moult and autumn migration. Despite this variation in energy budgets, the magnitude of the APR, as measured by all variables, was similar in all annual cycle stages. Thus, while we find evidence that some annual cycle stages are relatively more energetically constrained, we find no support for the hypothesis that during these annual cycle stages birds compromise an immune defence that is itself energetically costly. We suggest that the ability to mount an APR may be so essential to survival in every annual cycle stage that skylarks do not trade off this costly form of defence with other annual cycle demands. PMID:22570706

  1. Liver-derived ketone bodies are necessary for food anticipation

    PubMed Central

    Chavan, Rohit; Feillet, Céline; Costa, Sara S. Fonseca; Delorme, James E.; Okabe, Takashi; Ripperger, Jürgen A.; Albrecht, Urs

    2016-01-01

    The circadian system has endowed animals with the ability to anticipate recurring food availability at particular times of day. As daily food anticipation (FA) is independent of the suprachiasmatic nuclei, the central pacemaker of the circadian system, questions arise of where FA signals originate and what role components of the circadian clock might play. Here we show that liver-specific deletion of Per2 in mice abolishes FA, an effect that is rescued by viral overexpression of Per2 in the liver. RNA sequencing indicates that Per2 regulates β-hydroxybutyrate (βOHB) production to induce FA leading to the conclusion that liver Per2 is important for this process. Unexpectedly, we show that FA originates in the liver and not in the brain. However, manifestation of FA involves processing of the liver-derived βOHB signal in the brain, indicating that the food-entrainable oscillator is not located in a single tissue but is of systemic nature. PMID:26838474

  2. Intercalation of cyclic ketones into vanadyl phosphate

    SciTech Connect

    Zima, Vitezslav . E-mail: vitezslav.zima@upce.cz; Melanova, Klara; Benes, Ludvik; Trchova, Miroslava; Dybal, Jiri

    2005-01-15

    Intercalation compounds of vanadyl phosphate with cyclic ketones (cyclopentanone, cyclohexanone, 4-methylcyclohexanone, and 1,4-cyclohexanedione) were prepared from corresponding propanol or ethanol intercalates by a molecular exchange. The intercalates prepared were characterized using powder X-ray diffraction and thermogravimetric analysis. The intercalates are stable in dry environment and decompose slowly in humid air. Infrared and Raman spectra indicate that carbonyl oxygens of the guest molecules are coordinated to the vanadium atoms of the host layers. The local structure and interactions in the cyclopentanone intercalate have been suggested on the basis of quantum chemical calculations.

  3. Rhodium-catalyzed Asymmetric Hydrogenation of α-Dehydroamino Ketones: A General Approach to Chiral α-amino Ketones.

    PubMed

    Gao, Wenchao; Wang, Qingli; Xie, Yun; Lv, Hui; Zhang, Xumu

    2016-01-01

    Rhodium/DuanPhos-catalyzed asymmetric hydrogenation of aliphatic α-dehydroamino ketones has been achieved and afforded chiral α-amino ketones in high yields and excellent enantioselectives (up to 99 % ee), which could be reduced further to chiral β-amino alcohols by LiAlH(tBuO)3 with good yields. This protocol provides a readily accessible route for the synthesis of chiral α-amino ketones and chiral β-amino alcohols. PMID:26425824

  4. Polyfluorinated. cap alpha. ,. beta. -unsaturated ketons

    SciTech Connect

    Latypov, R.R.; Belogai, V.D.; Pashkevich, K.I.

    1986-07-10

    The ..cap alpha..,..beta..-unsaturated ketones (..cap alpha..,..beta..-UK), particularly those groups containing fluoroalkyl groups, are of interest as highly reactive compounds having two nonequivalent electrophilic centers. In the present investigation, by boiling polyfluorinated aldehydes with methylketones in glacial acetic acid, they have obtained for the first time the polyfluorinated ..beta..-hydroxy-ketones, the dehydration of which has been used to synthesize the corresponding polyfluorinated ..cap alpha..,..beta..-UK, and their structure and reactions with the nucleophiles NH/sub 3/, PhNH/sub 2/, MeOH have been studied. In the PMR spectra of the ..cap alpha..,..beta..-UK (X)-(XVI) two doublets of triplets are observed at 6.9 and 7.9 ppm, caused by the spin-spin coupling of the olefin protons with the CF/sub 2/ group of the substituent. For ..cap alpha..,..beta..-UK, apart from the cis-trans isomerism relative to the C=C bond, a rotational isomerism is possible, caused by rotation around the C-C single bond. The presence in the IR spectra of absorption bands from nonplanar torsion-deformation vibrations of C-H for a double bond (nu = 975-980 cm/sup -1/) and the high value of the spin-spin coupling constant of the olefin protons (J/sub HH/ = 15 Hz) indicate unambiguously the transconfiguration of the olefin protons.

  5. Energetic cost of communication

    PubMed Central

    Stoddard, Philip K.; Salazar, Vielka L.

    2011-01-01

    Communication signals may be energetically expensive or inexpensive to produce, depending on the function of the signal and the competitive nature of the communication system. Males of sexually selected species may produce high-energy advertisement signals, both to enhance detectability and to signal their size and body condition. Accordingly, the proportion of the energy budget allocated to signal production ranges from almost nothing for many signals to somewhere in excess of 50% for acoustic signals in short-lived sexually selected species. Recent data from gymnotiform electric fish reveal mechanisms that regulate energy allocated to sexual advertisement signals through dynamical remodeling of the excitable membranes in the electric organ. Further, males of the short-lived sexually selected species, Brachyhypopomus gauderio, trade off among different metabolic compartments, allocating energy to signal production while reducing energy used in other metabolic functions. Female B. gauderio, by contrast, do not trade off energy between signaling and other functions. To fuel energetically expensive signal production, we expect a continuum of strategies to be adopted by animals of different life history strategies. Future studies should explore the relation between life history and energy allocation trade-offs. PMID:21177941

  6. Can ketones compensate for deteriorating brain glucose uptake during aging? Implications for the risk and treatment of Alzheimer's disease.

    PubMed

    Cunnane, Stephen C; Courchesne-Loyer, Alexandre; St-Pierre, Valérie; Vandenberghe, Camille; Pierotti, Tyler; Fortier, Mélanie; Croteau, Etienne; Castellano, Christian-Alexandre

    2016-03-01

    Brain glucose uptake is impaired in Alzheimer's disease (AD). A key question is whether cognitive decline can be delayed if this brain energy defect is at least partly corrected or bypassed early in the disease. The principal ketones (also called ketone bodies), β-hydroxybutyrate and acetoacetate, are the brain's main physiological alternative fuel to glucose. Three studies in mild-to-moderate AD have shown that, unlike with glucose, brain ketone uptake is not different from that in healthy age-matched controls. Published clinical trials demonstrate that increasing ketone availability to the brain via moderate nutritional ketosis has a modest beneficial effect on cognitive outcomes in mild-to-moderate AD and in mild cognitive impairment. Nutritional ketosis can be safely achieved by a high-fat ketogenic diet, by supplements providing 20-70 g/day of medium-chain triglycerides containing the eight- and ten-carbon fatty acids octanoate and decanoate, or by ketone esters. Given the acute dependence of the brain on its energy supply, it seems reasonable that the development of therapeutic strategies aimed at AD mandates consideration of how the underlying problem of deteriorating brain fuel supply can be corrected or delayed. PMID:26766547

  7. Production of methyl-vinyl ketone from levulinic acid

    DOEpatents

    Dumesic, James A.; West; Ryan M.

    2011-06-14

    A method for converting levulinic acid to methyl vinyl ketone is described. The method includes the steps of reacting an aqueous solution of levulinic acid, over an acid catalyst, at a temperature of from room temperature to about 1100 K. Methyl vinyl ketone is thereby formed.

  8. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Methyl n-butyl ketone. 721.4925 Section 721.4925 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4925 Methyl n-butyl ketone....

  9. 27 CFR 21.117 - Methyl isobutyl ketone.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.117 Methyl isobutyl ketone. (a)...

  10. 27 CFR 21.117 - Methyl isobutyl ketone.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.117 Methyl isobutyl ketone. (a)...

  11. 27 CFR 21.117 - Methyl isobutyl ketone.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.117 Methyl isobutyl ketone. (a)...

  12. 27 CFR 21.117 - Methyl isobutyl ketone.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.117 Methyl isobutyl ketone. (a)...

  13. IRIS TOXICOLOGICAL REVIEW OF METHYL ETHYL KETONE (2003 Final)

    EPA Science Inventory

    EPA is announcing the release of the final report, "Toxicological Review of Methyl Ethyl Ketone: in support of the Integrated Risk Information System (IRIS)". The updated Summary for Methyl Ethyl Ketone and accompanying Quickview have also been added to the IRIS Database.

  14. Decarboxylative dearomatization and mono-α-arylation of ketones.

    PubMed

    Mendis, Shehani N; Tunge, Jon A

    2016-06-01

    We report the first example of a palladium-catalyzed decarboxylative dearomatization reaction that occurs via Pd-π-benzyl intermediates. In fact, the Pd-catalyzed decarboxylative cross-coupling reaction of benzyl enol carbonates can lead to either the dearomatized alicyclic ketones or α-monoarylated ketone products depending on the catalyst and ligand employed. PMID:27229656

  15. A sulfonated poly (aryl ether ether ketone ketone) isomer: synthesis and DMFC performance

    SciTech Connect

    Kim, Yu Seung; Liu, Baijun; Hu, Wei; Jiang, Zhenhua; Robertson, Gilles; Guiver, Michael

    2009-01-01

    A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily-prepared PEEKK post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported analogues and eveluated Nafion membranes.

  16. Metal-Catalysed Transfer Hydrogenation of Ketones.

    PubMed

    Štefane, Bogdan; Požgan, Franc

    2016-04-01

    We highlight recent developments of catalytic transfer hydrogenation of ketones promoted by transition metals, while placing it within its historical context. Since optically active secondary alcohols are important building blocks in fine chemicals synthesis, the focus of this review is devoted to chiral catalyst types which are capable of inducing high stereoselectivities. Ruthenium complexes still represent the largest part of the catalysts, but other metals (e.g. Fe) are rapidly penetrating this field. While homogeneous transfer hydrogenation catalysts in some cases approach enzymatic performance, the interest in heterogeneous catalysts is constantly growing because of their reusability. Despite excellent activity, selectivity and compatibility of metal complexes with a variety of functional groups, no universal catalysts exist. Development of future catalyst systems is directed towards reaching as high as possible activity with low catalyst loadings, using "greener" conditions, and being able to operate under mild conditions and in a highly selective manner for a broad range of substrates. PMID:27573143

  17. Analysis of the energetic metabolism in cyclic Bedouin goats (Capra hircus): Nychthemeral and seasonal variations of some haematochemical parameters in relation with body and ambient temperatures.

    PubMed

    Malek, Mouna; Amirat, Zaina; Khammar, Farida; Khaldoun, Mounira

    2016-08-01

    Several studies have examined changes in some haematochemical parameters as a function of the different physiological status (cyclic, pregnant and lactating) of goats, but no relevant literature has exhaustively investigated these variations from anestrous to estrous stages in cyclic goats. In this paper, we report nychthemeral and seasonal variations in ambient and body temperatures, and in some haematochemical parameters (glycemia, cholesterolemia, triglyceridemia, creatininemia and uremia) measured during summer, winter and spring, in seven (7) experimental cyclic female Bedouin goats (Capra hircus) living in the Béni-Abbès region (Algerian Sahara desert). Cosinor rhythmometry procedure was used to determine the rhythmic parameters of ambient temperature and haematochemical parameters. To determine the effect of time of day on the rhythmicity of the studied parameters, as well as their seasonality, repeated measure analysis of variance (ANOVA) was applied. The results showed that in spite of the nychthemeral profile presented by the ambient temperature for each season, the body temperature remained in a narrow range, thus indicating a successful thermoregulation. The rhythmometry analysis showed a circadian rhythmicity of ambient temperature and haematochemical parameters with diurnal acrophases. A statistically significant effect of the time of day was shown on all studied haematochemical parameters, except on creatininemia. It was also found that only uremia, cholesterolemia and triglyceridemia followed the seasonal sexual activity of the studied ruminant. This study demonstrated the good physiological adaptation developed by this breed in response to the harsh climatic conditions of its natural environment. PMID:27503720

  18. Engineering of Bacterial Methyl Ketone Synthesis for Biofuels

    PubMed Central

    Goh, Ee-Been; Baidoo, Edward E. K.; Keasling, Jay D.

    2012-01-01

    We have engineered Escherichia coli to overproduce saturated and monounsaturated aliphatic methyl ketones in the C11 to C15 (diesel) range; this group of methyl ketones includes 2-undecanone and 2-tridecanone, which are of importance to the flavor and fragrance industry and also have favorable cetane numbers (as we report here). We describe specific improvements that resulted in a 700-fold enhancement in methyl ketone titer relative to that of a fatty acid-overproducing E. coli strain, including the following: (i) overproduction of β-ketoacyl coenzyme A (CoA) thioesters achieved by modification of the β-oxidation pathway (specifically, overexpression of a heterologous acyl-CoA oxidase and native FadB and chromosomal deletion of fadA) and (ii) overexpression of a native thioesterase (FadM). FadM was previously associated with oleic acid degradation, not methyl ketone synthesis, but outperformed a recently identified methyl ketone synthase (Solanum habrochaites MKS2 [ShMKS2], a thioesterase from wild tomato) in β-ketoacyl-CoA-overproducing strains tested. Whole-genome transcriptional (microarray) studies led to the discovery that FadM is a valuable catalyst for enhancing methyl ketone production. The use of a two-phase system with decane enhanced methyl ketone production by 4- to 7-fold in addition to increases from genetic modifications. PMID:22038610

  19. Point-of-Care Glucose and Ketone Monitoring.

    PubMed

    Chong, Siew Kim; Reineke, Erica L

    2016-03-01

    Early and rapid identification of hypo- and hyperglycemia as well as ketosis is essential for the practicing veterinarian as these conditions can be life threatening and require emergent treatment. Point-of-care testing for both glucose and ketone is available for clinical use and it is important for the veterinarian to understand the limitations and potential sources of error with these tests. This article discusses the devices used to monitor blood glucose including portable blood glucose meters, point-of-care blood gas analyzers and continuous glucose monitoring systems. Ketone monitoring options discussed include the nitroprusside reagent test strips and the 3-β-hydroxybutyrate ketone meter. PMID:27451045

  20. Substrate-controlled Michael additions of chiral ketones to enones.

    PubMed

    Fàbregas, Mireia; Gómez-Palomino, Alejandro; Pellicena, Miquel; Reina, Daniel F; Romea, Pedro; Urpí, Fèlix; Font-Bardia, Mercè

    2014-12-01

    Substrate-controlled Michael additions of the titanium(IV) enolate of lactate-derived ketone 1 to acyclic α,β-unsaturated ketones in the presence of a Lewis acid (TiCl4 or SnCl4) provide the corresponding 2,4-anti-4,5-anti dicarbonyl compounds in good yields and excellent diastereomeric ratios. Likely, the nucleophilic species involved in such additions are bimetallic enolates that may add to enones through cyclic transition states. Finally, further studies indicate that a structurally related β-benzyloxy chiral ketone can also participate in such stereocontrolled conjugate additions. PMID:25423031

  1. The collective therapeutic potential of cerebral ketone metabolism in traumatic brain injury

    PubMed Central

    Prins, Mayumi L.; Matsumoto, Joyce H.

    2014-01-01

    The postinjury period of glucose metabolic depression is accompanied by adenosine triphosphate decreases, increased flux of glucose through the pentose phosphate pathway, free radical production, activation of poly-ADP ribose polymerase via DNA damage, and inhibition of glyceraldehyde dehydrogenase (a key glycolytic enzyme) via depletion of the cytosolic NAD pool. Under these post-brain injury conditions of impaired glycolytic metabolism, glucose becomes a less favorable energy substrate. Ketone bodies are the only known natural alternative substrate to glucose for cerebral energy metabolism. While it has been demonstrated that other fuels (pyruvate, lactate, and acetyl-L-carnitine) can be metabolized by the brain, ketones are the only endogenous fuel that can contribute significantly to cerebral metabolism. Preclinical studies employing both pre- and postinjury implementation of the ketogenic diet have demonstrated improved structural and functional outcome in traumatic brain injury (TBI) models, mild TBI/concussion models, and spinal cord injury. Further clinical studies are required to determine the optimal method to induce cerebral ketone metabolism in the postinjury brain, and to validate the neuroprotective benefits of ketogenic therapy in humans. PMID:24721741

  2. Coulometric generation of hydrogen ions by oxidation of mercury in methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.

    PubMed

    Mihajlović, R P; Joksimović, V M; Mihajlović, Lj V

    2003-11-01

    Mercury(II)-chloride reacts with anhydrous methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone in a precise stoichiometry ratio (1:2), and weakly ionized compounds of mercury with ketones are formed and equivalent quantity of HCl is released. The application of a mercury anode for the quantitative generation of H(+) ions in 0.25 M sodium perchlorate in anhydrous methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone has been investigated. Current/potentials curves for the solvents, titrated bases, indicator and mercury showed that in these solvents mercury is oxidized at potentials much more negative than those for the titrated bases and other components present in the solution. The protons generated in this way have been used for the titration of some organic bases, with either visual or potentiometric end-point detection. The oxidation of mercury in methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone and the reaction of mercury ions with these solvents have been found to proceed with 100% current efficiency. PMID:18969192

  3. Oxidative acetoxylation of the silyl ethers of ketone enols

    SciTech Connect

    Brunovlenskaya, I.I.; Kusainova, K.M.; Kashin, A.K.

    1988-07-20

    The authors studied the reaction of (dicarboxyiodo)benzenes with the trimethylsilyl ethers of ketone enols having various structures. They also undertook a comparative investigation of the oxidation of these compounds with lead tetraacetate. The reaction of (diacetoxyiodo)benzene with the trimethylsilyl ethers of ketone enols takes place with retention of the (CH/sub 3/)/sub 3/Si group in two directions, i.e., substitution of the vinylic hydrogen or diacetoxylation of the double bond. The reaction can be used for the regioselective synthesis of /alpha/-acetoxy ketones, since the trimethylsilyl group is readily eliminated from the obtained products by the action of fluoride ion or boron trifluoride etherate with the formation of the corresponding substituted ketones.

  4. Copper/Manganese Cocatalyzed Oxidative Coupling of Vinylarenes with Ketones.

    PubMed

    Lan, Xing-Wang; Wang, Nai-Xing; Zhang, Wei; Wen, Jia-Long; Bai, Cui-Bing; Xing, Yalan; Li, Yi-He

    2015-09-18

    A novel copper/manganese cocatalyzed direct oxidative coupling of terminal vinylarenes with ketones via C(sp(3))-H bond functionalization following C-C bond formation has been developed using tert-butyl hydroperoxide as the radical initiator. Various ketones underwent a free-radical addition of terminal vinylarenes to give the corresponding 1,4-dicarbonyl products with excellent regioselectivity and efficiency through one step. A possible reaction mechanism has been proposed. PMID:26348870

  5. Pair-Pair Approximation to the Generalized Many-Body Expansion: An Alternative to the Four-Body Expansion for ab Initio Prediction of Protein Energetics via Molecular Fragmentation.

    PubMed

    Liu, Jie; Herbert, John M

    2016-02-01

    We introduce a "pair-pair" approximation to the generalized many-body expansion (pp-GMBE) as an approximation to a traditional four-body expansion, the latter of which is accurate but quickly becomes numerically unstable and ultimately intractable as the number of "bodies" (fragments) increases. The pp-GMBE method achieves a good balance between accuracy and efficiency by defining significant fragment pairs and then fragment quartets. An efficient fragmentation scheme is introduced for proteins such that the largest subsystems contain about 60 atoms. Application of the pp-GMBE method to proteins with as many as 70 amino acids (1142 atoms) reveals that pp-GMBE energies are quite faithful to those obtained when the same level of density functional theory is applied to the entire macromolecule. When combined with embedding charges obtained from natural population analysis, the pp-GMBE approach affords absolute energies that differ by 1-3 kcal/mol from full supersystem results, but it yields conformational energy profiles that are practically indistinguishable from the supersystem calculation at the same level of theory. PMID:26730608

  6. Rotational Spectroscopy of Methyl Vinyl Ketone

    NASA Astrophysics Data System (ADS)

    Zakharenko, Olena; Motiyenko, R. A.; Aviles Moreno, Juan-Ramon; Huet, T. R.

    2015-06-01

    Methyl vinyl ketone, MVK, along with previously studied by our team methacrolein, is a major oxidation product of isoprene, which is one of the primary contributors to annual global VOC emissions. In this talk we present the analysis of the rotational spectrum of MVK recorded at room temperature in the 50 -- 650 GHz region using the Lille spectrometer. The spectroscopic characterization of MVK ground state will be useful in the detailed analysis of high resolution infrared spectra. Our study is supported by high level quantum chemical calculations to model the structure of the two stable s-trans and s-cis conformers and to obtain the harmonic force field parameters, internal rotation barrier heights, and vibrational frequencies. In the Doppler-limited spectra the splittings due to the internal rotation of methyl group are resolved, therefore for analysis of this molecule we used the Rho-Axis-Method Hamiltonian and RAM36 code to fit the rotational transitions. At the present time the ground state of two conformers is analyzed. Also we intend to study some low lying excited states. The analysis is in progress and the latest results will be presented. Support from the French Laboratoire d'Excellence CaPPA (Chemical and Physical Properties of the Atmosphere) through contract ANR-10-LABX-0005 of the Programme d'Investissements d'Avenir is acknowledged.

  7. Studies on Crystalline Structure of Poly(aryl ether ketone ketone) Copolymer

    NASA Astrophysics Data System (ADS)

    Honigfort, P. S.; Ho, R. M.; Cheng, S. Z. D.

    1998-03-01

    Recent studies on the Poly(aryl ether ketone ketone) [PEKK(T/I)] copolymer containing alternating terphthalic acid (T) and isopthalic acid (I) linked phenylene units have left unanswered polymorphic questions. To help answer these questions a PEKK(T/I) oligomer was prepared and its crystal structure was investigated and compared to results from the copolymer. Evidence was found for 3 different crystal forms. When the copolymer is crystallized near 300 C, only one orthorhombic unit cell (form I) forms, and these crystals are also evident in the oligomer. At crystallization temperatures below 210 C, another crystal unit cell (form II) occurs which can also be isolated in the oligomer. Also, evidence for a new form (form III), which coexists with both form I and II was identified in both the copolymer and the oligomer between 200 and 280 C. Evidence of a larger supercell symmetry consisting of 3 unit cells staggered in the a-axis dimension was seen in electron diffraction studies of form III. This research was supported by WSFDMR(96-17030).

  8. The partitioning of ketones between the gas and aqueous phases

    NASA Astrophysics Data System (ADS)

    Betterton, Eric A.

    Most ketones are not significantly hydrated; they therefore retain their chromophore and they could be photolytically degraded in solution yielding a variety of products including carboxylic acids, aldehydes and radicals. It is difficult to accurately model the partitioning of ketones between the gas phase and aqueous phase because of the lack suitable estimates of the Henry's Law constants; consequently the fate and environmental effects of ketones cannot be confidently predicted. Here we report the experimental determination of the Henry's Law constants of a series of ketones that has yielded a simple straight line equation to predict the Henry's Law constants of simple aliphatic ketones: log H ∗ =0.23Σσ ∗ + 1.51; where H ∗ is the effective Henry's Law constant (M atm -1, and Σσ ∗ is the Taft polar substituents constants. The results for 25°C are (M atm -1) CH 3COCH 3, 32; C 6H 5COCH 3, 110; CH 2ClCOCH 3, 59; CH 3COCOCH 3, 74; CF 3COCH 3, 138. Acetophenone appears to have an abnormally high H ∗. Most low molecular weight aliphatic ketones are predicted to characterized by H ∗⩾30 M atm -1 and therefore they are expected to be found in the aqueous phase at concentrations of ⩾5 - 0.5 μM (given a typical gas-phase concentration range of 1-10 ppbv). The expected rate of decomposition of ketones due to photolysis in hydrometers is briefly discussed.

  9. Mechanisms and reactivity differences for the cobalt-catalyzed enantioselective intramolecular hydroacylation of ketones and alkenes: insights from density functional calculations.

    PubMed

    Meng, Qingxi; Wang, Fen

    2016-03-01

    Density functional theory (DFT) was used to study the cobalt(I)-catalyzed enantioselective intramolecular hydroacylation of ketones and alkenes. All intermediates and transition states were fully optimized at the M06/6-31G(d,p) level (LANL2DZ(f) for Co). The results demonstrated that the ketone and alkene present different reactivities in the enantioselective hydroacylation. In ketone hydroacylation catalyzed by the cobalt(I)-(R,R)-Ph-BPE complex, reaction channel "a" to (R)-phthalide was more favorable than channel "b" to (S)-phthalide. Hydrogen migration was both the rate-determining and chirality-limiting step, and this step was endothermic. In alkene hydroacylation catalyzed by the cobalt(I)-(R,R)-BDPP complex, reaction channel "c" leading to the formation of (S)-indanone was the most favorable, both thermodynamically and kinetically. Reductive elimination was the rate-determining step, but the chirality-limiting step was hydrogen migration, which occurred easily. The results also indicated that the alkene hydroacylation leading to (S)-indanone formation was more energetically favorable than the ketone hydroacylation that gave (R)-phthalide, both thermodynamically and kinetically. PMID:26888484

  10. Stereoselective Reduction of Prochiral Ketones by Plant and Microbial Biocatalysts.

    PubMed

    Javidnia, K; Faghih-Mirzaei, E; Miri, R; Attarroshan, M; Zomorodian, K

    2016-01-01

    Chiral alcohols are the key chiral building blocks to many enantiomerically pure pharmaceuticals. The biocatalytic approach in asymmetric reduction of corresponding prochiral ketones to the preparation of these optically pure substances is one of the most promising routes. The stereoselective reduction of different kinds of prochiral ketones catalyzed by various plants and microorganisms was studied in this work. Benzyl acetoacetate, methyl 3-oxopentanoate, ethyl 3-oxopentanoate, and ethyl butyryl acetate were chosen as the model substrates for β-ketoesters. Benzoyl acetonitrile, 3-chloro propiophenone, and 1-acetyl naphthalene were chosen as aromatic aliphatic ketones. Finally, 2-methyl benzophenone and 4-chloro benzophenone were selected as diaryl ketones. Plant catalysis was conducted by Daucus carota, Brassica rapa, Brassica oleracea, Pastinaca sativa, and Raphnus sativus. For microbial catalysis, Aspergillus foetidus, Penicillum citrinum, Saccharomyces carlbergensis, Pichia fermentans, and Rhodotrula glutinis were chosen. Chiral alcohols were obtained in high yields and with optical purity. A superiority in the microorganisms' performance in the bioreduction of prochiral ketones was detected. Among microorganisms, Rhodotrula glutinis showed remarkable results with nearly all substrates and is proposed for future studies. PMID:27168684

  11. Stereoselective Reduction of Prochiral Ketones by Plant and Microbial Biocatalysts

    PubMed Central

    Javidnia, K.; Faghih-Mirzaei, E.; Miri, R.; Attarroshan, M.; Zomorodian, K.

    2016-01-01

    Chiral alcohols are the key chiral building blocks to many enantiomerically pure pharmaceuticals. The biocatalytic approach in asymmetric reduction of corresponding prochiral ketones to the preparation of these optically pure substances is one of the most promising routes. The stereoselective reduction of different kinds of prochiral ketones catalyzed by various plants and microorganisms was studied in this work. Benzyl acetoacetate, methyl 3-oxopentanoate, ethyl 3-oxopentanoate, and ethyl butyryl acetate were chosen as the model substrates for β-ketoesters. Benzoyl acetonitrile, 3-chloro propiophenone, and 1-acetyl naphthalene were chosen as aromatic aliphatic ketones. Finally, 2-methyl benzophenone and 4-chloro benzophenone were selected as diaryl ketones. Plant catalysis was conducted by Daucus carota, Brassica rapa, Brassica oleracea, Pastinaca sativa, and Raphnus sativus. For microbial catalysis, Aspergillus foetidus, Penicillum citrinum, Saccharomyces carlbergensis, Pichia fermentans, and Rhodotrula glutinis were chosen. Chiral alcohols were obtained in high yields and with optical purity. A superiority in the microorganisms' performance in the bioreduction of prochiral ketones was detected. Among microorganisms, Rhodotrula glutinis showed remarkable results with nearly all substrates and is proposed for future studies. PMID:27168684

  12. Chapter 4: Measuring Energetics of Biological Processes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measurement of the energetics of biological processes is the key component in understanding the thermodynamic responses of homoeothermic animals to the environment. For these animals to achieve body temperature control, they must adapt to thermal-environmental conditions and variations caused by wea...

  13. METHYL KETONE METABOLISM IN HYDROCARBON-UTILIZING MYCOBACTERIA

    PubMed Central

    Lukins, H. B.; Foster, J. W.

    1963-01-01

    Lukins, H. B. (University of Texas, Austin) and J. W. Foster. Methyl ketone metabolism in hydrocarbon-utilizing mycobacteria. J. Bacteriol. 85: 1074–1087. 1963.—Species of Mycobacterium especially M. smegmatis 422, produced the homologous methyl ketones during the oxidation of propane, n-butane, n-pentane, or n-hexane. A carrier-trapping experiment demonstrated the formation of 2-undecanone, as well as 1,11-undecanedioic acid, during the oxidation of undecane-1-C14. Aliphatic alkane-utilizing mycobacteria were able to grow at the expense of several aliphatic methyl ketones as sole sources of carbon. Other ketones which did not support growth were oxidized by resting bacterial suspensions. M. smegmatis 422 cells grown on propane or acetone were simultaneously adapted to oxidize both substrates, as well as n-propanol. n-Propanol cells were unadapted to propane or acetone. Acetone produced from propane in a medium enriched in D2O contained a negligible quantity of D, presumably eliminating propylene as an intermediate in the oxidation. Cells grown at the expense of alkanes or methyl ketones in the presence of O218 had a higher content of O18 than did cells grown on terminally oxidized compounds, e.g., primary alcohols or fatty acids. An oxygenase reaction is postulated for the attack on methyl ketones. Acetol was isolated and characterized as an oxidation product of acetone by M. smegmatis 422. Acetol-grown cells had a higher O18 content than did n-propanol cells, and its utilization appears to involve at least one oxygenase reaction. Acetol produced from acetone in the presence of O218 was not enriched in the isotope, indicating the occurrence of exchange reactions or of oxygenation reactions at a later stage in the assimilation of acetone and acetol. PMID:14043998

  14. Catalytic Intramolecular Ketone Alkylation with Olefins by Dual Activation.

    PubMed

    Lim, Hee Nam; Dong, Guangbin

    2015-12-01

    Two complementary methods for catalytic intramolecular ketone alkylation reactions with unactivated olefins, resulting in Conia-ene-type reactions, are reported. The transformations are enabled by dual activation of both the ketone and the olefin and are atom-economical as stoichiometric oxidants or reductants are not required. Assisted by Kool's aniline catalyst, the reaction conditions can be both pH- and redox-neutral. A broad range of functional groups are thus tolerated. Whereas the rhodium catalysts are effective for the formation of five-membered rings, a ruthenium-based system that affords the six-membered ring products was also developed. PMID:26486569

  15. Asymmetric reduction of ketones with recombinant E. coli whole cells in neat substrates.

    PubMed

    Jakoblinnert, Andre; Mladenov, Radoslav; Paul, Albert; Sibilla, Fabrizio; Schwaneberg, Ulrich; Ansorge-Schumacher, Marion B; de María, Pablo Domínguez

    2011-11-28

    The asymmetric reduction of ketones is performed by using lyophilized whole cells in neat substrates with defined water activity (a(w)). Ketones and alcohols prone to be unstable in aqueous media can now be converted via biocatalysis. PMID:22005469

  16. Crystal morphology and phase identifications in poly(aryl ether ketones)s and their copolymers

    SciTech Connect

    Ho, R.M.; Cheng, S.Z.D.; Hsiao, B.S.

    1995-12-01

    A series of poly(aryl ether ketone ketone)s prepared from diphenyl ether (DPE) and terephthalic acid M or isophthalic acid (T) have been investigated. PEKK(T) has been reported to exhibit two polymorphism (form I and form II) based on wide angle X-ray diffraction (WAXD) and electron diffraction (ED) experiments.

  17. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ketones (nonquantitative) test system. 862.1435 Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  18. ANALYSIS OF ALDEHYDES AND KETONES IN THE GAS PHASE

    EPA Science Inventory

    The development and testing of a 2,4-dinitrophenylhydrazine-acetonitrile (DNPH-ACN) method for the analysis of aldehydes and ketones in ambient air are described. A discussion of interferences, preparation of calibration standards, analytical testing, fluorescence methods and car...

  19. Ketonization of Cuphea oil for the production of 2-undecanone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this work was to demonstrate the viability of the cross ketonization reaction with the triacylglycerol from Cuphea sp. and acetic acid in a fixed-bed plug-flow reactor. The seed oil from Cuphea sp. contains up to 71% decanoic acid and the reaction of this fatty acid residue with ac...

  20. Cookoff of energetic materials

    SciTech Connect

    Baer, M.R.; Hobbs, M.L.; Gross, R.J.; Schmitt, R.G.

    1998-09-01

    An overview of cookoff modeling at Sandia National Laboratories is presented aimed at assessing the violence of reaction following cookoff of confined energetic materials. During cookoff, the response of energetic materials is known to involve coupled thermal/chemical/mechanical processes which induce thermal damage to the energetic material prior to the onset of ignition. These damaged states enhance shock sensitivity and lead to conditions favoring self-supported accelerated combustion. Thus, the level of violence depends on the competition between pressure buildup and stress release due to the loss of confinement. To model these complex processes, finite element-based analysis capabilities are being developed which can resolve coupled heat transfer with chemistry, quasi-static structural mechanics and dynamic response. Numerical simulations that assess the level of violence demonstrate the importance of determining material damage in pre- and post-ignition cookoff events.

  1. Inhalation developmental toxicology studies: Teratology study of methyl ethyl ketone in mice: Final report

    SciTech Connect

    Mast, T.J.; Dill, J.A.; Evanoff, J.J.; Rommereim, R.L.; Weigel, R.J.; Westerberg, R.B.

    1989-02-01

    Methyl ethyl ketone (MEK) is a widely used industrial solvent which results in considerable human exposure. In order to assess the potential for MEK to cause developmental toxicity in rodents, four groups of Swiss (CD-1) mice were exposed to 0, 400, 1000 or 3000 ppM MEK vapors, 7 h/day, 7 dy/wk. Ten virgin females and approx.30 plug-positive females per group were exposed concurrently for 10 consecutive days (6--15 dg for mated mice). Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice on 18 dg. Uterine implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. Exposure of pregnant mice to these concentrations of MEK did not result in apparent maternal toxicity, although there was a slight, treatment-correlated increase in liver to body weight ratios which was significant for the 3000-ppM group. Mild developmental toxicity was evident at 3000-ppM as a reduction in mean fetal body weight. This reduction was statistically significant for the males only, although the relative decrease in mean fetal body weight was the same for both sexes. 17 refs., 4 figs., 10 tabs.

  2. INTENSE ENERGETIC GAS DISCHARGE

    DOEpatents

    Luce, J.S.

    1960-03-01

    A method and apparatus for initiating and sustaining an energetic gas arc discharge are described. A hollow cathode and a hollow anode are provided. By regulating the rate of gas flow into the interior of the cathode, the arc discharge is caused to run from the inner surface of the cathode with the result that adequate space-charge neutralization is provided inside the cathode but not in the main arc volume. Thus, the gas fed to the cathode is substantially completely ionized before it leaves the cathode, with the result that an energetic arc discharge can be maintained at lower operating pressures.

  3. Novel sulfonated poly(ether ether ketone ketone)s for direct methanol fuel cells usage: Synthesis, water uptake, methanol diffusion coefficient and proton conductivity

    NASA Astrophysics Data System (ADS)

    Zhang, Gang; Fu, Tiezhu; Shao, Ke; Li, Xianfeng; Zhao, Chengji; Na, Hui; Zhang, Hong

    A novel series of sulfonated poly(ether ether ketone ketone)s (SPEEKKs) with different degrees of sulfonation (Ds) were synthesized from 1,3-bis(3-sodium sulfonate-4-fluorobenzoyl)benzene (1,3-SFBB-Na), 1,3-bis(4-fluorobenzoyl)benzene (1,3-FBB) and 3,3‧,5,5‧-tetramethyl-4,4‧-biphenol (TMBP) by aromatic nucleophilic polycondensation. The chemical structures of SPEEKKs were confirmed by FT-IR spectroscopy and the Ds values of the polymers were calculated by 1H NMR and titration methods, respectively. The thermal stabilities of the SPEEKKs in acid and sodium forms were characterized by thermogravimetric analysis (TGA), which showed that SPEEKKs had excellent thermal properties at high temperatures. All the SPEEKK polymers were easily solution cast into tough membranes. Water uptakes, proton conductivities and methanol diffusion coefficients of the SPEEKK membranes were measured. Water uptake increased with Ds and temperature. Compared to Nafion, the SPEEKK-60, -70 and -80 membranes showed higher proton conductivities at 80 °C, while the other SPEEKK membranes showed relatively lower proton conductivities. This may be due to the different distribution of ion-conducting domains in membrane. However, these membranes showed lower methanol diffusions in the range of 8.32 × 10 -9 to 1.14 × 10 -7 cm 2 s -1 compared with that of Nafion (2 × 10 -6 cm 2 s -1) at the same temperature. The membranes also showed excellent mechanical properties (with a Young's modulus > 1 GPa and a tensile strength > 40 MPa). These results indicate that the SPEEKK membranes are promising materials for use in direct methanol fuel cell (DMFC) applications.

  4. Mitochondrial Energetics and Therapeutics

    PubMed Central

    Wallace, Douglas C.; Fan, Weiwei; Procaccio, Vincent

    2011-01-01

    Mitochondrial dysfunction has been linked to a wide range of degenerative and metabolic diseases, cancer, and aging. All these clinical manifestations arise from the central role of bioenergetics in cell biology. Although genetic therapies are maturing as the rules of bioenergetic genetics are clarified, metabolic therapies have been ineffectual. This failure results from our limited appreciation of the role of bioenergetics as the interface between the environment and the cell. A systems approach, which, ironically, was first successfully applied over 80 years ago with the introduction of the ketogenic diet, is required. Analysis of the many ways that a shift from carbohydrate glycolytic metabolism to fatty acid and ketone oxidative metabolism may modulate metabolism, signal transduction pathways, and the epigenome gives us an appreciation of the ketogenic diet and the potential for bioenergetic therapeutics. PMID:20078222

  5. Functionalization of poly(aryl ether ether ketone)

    SciTech Connect

    Wang, Fei; Roovers, J.

    1993-12-31

    Bromomethyl and dibromomethyl substituted poly(aryl ether ether ketone) have been prepared from methyl poly(aryl ether ether ketone) by bromination with bromine. These brominated polymers are intermediates that can be further functionalized by: hydrolysis, oxidation, substitution etc. A series of new functionalized PEEK polymers has been prepared. The functional group includes -CH{sub 2}OH, -CH{sub 2}OCH{sub 3}, -CHO, -COOH, -COOCH{sub 3}, -CH{sub 2}CN, -CH{sub 2}COOH, -CH{sub 2}OCOCH{sub 3}, -CH{sub 2}N{sup +}H(CH{sub 2}CH{sub 3}){sub 2}Br{sup {minus}}, -CH{sub 2}N(CH{sub 2}CH{sub 3}){sub 2}, -CH{sub 2}N{sup +}H(CH{sub 2}CH{sub 3}){sub 3}Br{sup {minus}}.

  6. A constitutive model of polyether-ether-ketone (PEEK).

    PubMed

    Chen, Fei; Ou, Hengan; Lu, Bin; Long, Hui

    2016-01-01

    A modified Johnson-Cook (JC) model was proposed to describe the flow behaviour of polyether-ether-ketone (PEEK) with the consideration of coupled effects of strain, strain rate and temperature. As compared to traditional JC model, the modified one has better ability to predict the flow behaviour at elevated temperature conditions. In particular, the yield stress was found to be inversely proportional to temperature from the predictions of the proposed model. PMID:26409233

  7. Catalytic Leuckart-Wallach-type reductive amination of ketones.

    PubMed

    Kitamura, Masato; Lee, Donghyun; Hayashi, Shinnosuke; Tanaka, Shinji; Yoshimura, Masahiro

    2002-11-29

    A CpRh(III) complex catalyzes reductive amination of ketones using HCOONH(4) at 50-70 degrees C to give the corresponding primary amines in high yields. The reaction is clean and operationally simple and proceeds at a lower temperature and with higher chemoselectivity than the original Leuckart-Wallach reaction. The new method has been applied to the synthesis of alpha-amino acids directly from alpha-keto acids. PMID:12444661

  8. Trifluoromethyl ketones as inhibitors of the processionary moth sex pheromone.

    PubMed

    Parrilla, A; Guerrero, A

    1994-02-01

    Aliphatic and aromatic trifluoromethyl ketones have been evaluated in the laboratory and in the field as inhibitors of the pheromone response of the processionary moth Thaumetopoea pityocampa males. Among them, two compounds, (Z)-1,1,1-trifluoro-15-octadecen-13-yn-2-one and (Z)-1,1,1-trifluoro-16-nonadecen-14-yn-2-one, are closely related analogs of the natural pheromone (Z)-13-hexadecen-11-ynyl acetate. In the laboratory experiments, carried out by pre-exposure of males to vapors of the chemicals, alpha-naphthyl trifluoromethyl ketone, beta-naphthyl trifluoromethyl ketone, 1,1,1-trifluorotetradecan-2-one and (Z)-16-nonadecen-14-yn-2-one displayed notable blockage of the pheromone detection on EAG. The activity of 1,1,1-trifluorotetradecan-2-one is postulated to be due to the inhibition of the pheromone-degrading esterase. In general, the compounds have shown low specificity for the substrate and exhibited only a modest or null EAG intrinsic activity. In the field, benzyl trifluoromethyl ketone, trifluoroacetophenone, (Z)-1,1,1-trifluoro-15-octadecen-13-yn-2-one, (Z)-1,1,1-trifluoro-16-nonadecen-14-yn-2-one and beta-naphthyl trifluoroacetate showed a remarkable disruptant effect when mixed with the pheromone in 1:0.1, 1:1 and 1:10 ratio. (Z)-16-Nonadecen-14-yn-2-one has been found to be a modest agonist of the natural pheromone, exhibiting an attractant activity threefold lower than the parent molecule. PMID:8055254

  9. Low-temperature combustion chemistry of novel biofuels: resonance-stabilized QOOH in the oxidation of diethyl ketone.

    PubMed

    Scheer, Adam M; Welz, Oliver; Zádor, Judit; Osborn, David L; Taatjes, Craig A

    2014-07-14

    The Cl˙ initiated oxidation reactions of diethyl ketone (DEK; 3-pentanone; (CH3CH2)2C=O), 2,2,4,4-d4-diethyl ketone (d4-DEK; (CH3CD2)2C=O) and 1,1,1,5,5,5-d6-diethyl ketone (d6-DEK; (CD3CH2)2C=O) are studied at 8 Torr and 550-650 K using Cl2 as a source for the pulsed-photolytic generation of Cl˙. Products are monitored as a function of reaction time, mass, and photoionization energy using multiplexed photoionization mass spectrometry with tunable synchrotron radiation. Adding a large excess of O2 to the reacting flow allows determination of products resulting from oxidation of the initial primary (Rp) and secondary (Rs) radicals formed via the Cl˙ + DEK reaction. Because of resonance stabilization, the secondary DEK radical (3-oxopentan-2-yl) reaction with O2 has a shallow alkyl peroxy radical (RsO2) well and no energetically low-lying product channels. This leads to preferential back dissociation of RsO2 and a greater likelihood of consumption of Rs by competing radical-radical reactions. On the other hand, reaction of the primary DEK radical (3-oxopentan-1-yl) with O2 has several accessible bimolecular product channels. Vinyl ethyl ketone is observed from HO2-elimination from the DEK alkylperoxy radicals, and small-molecule products are identified from β-scission reactions and decomposition reactions of oxy radical secondary products. Although channels yielding OH + 3-, 4-, 5- and 6-membered ring cyclic ether products are possible in the oxidation of DEK, at the conditions of this study (8 Torr, 550-650 K) only the 5-membered ring, 2-methyltetrahydrofuran-3-one, is observed in significant quantities. Computation of relevant stationary points on the potential energy surfaces for the reactions of Rp and Rs with O2 indicates this cyclic ether is formed via a resonance-stabilized hydroperoxyalkyl radical (QOOH) intermediate, formed from isomerization of the RpO2 radical. PMID:24585023

  10. Solvation of Esters and Ketones in Supercritical CO2.

    PubMed

    Kajiya, Daisuke; Imanishi, Masayoshi; Saitow, Ken-ichi

    2016-02-01

    Vibrational Raman spectra for the C═O stretching modes of three esters with different functional groups (methyl, a single phenyl, and two phenyl groups) were measured in supercritical carbon dioxide (scCO2). The results were compared with Raman spectra for three ketones involving the same functional groups, measured at the same thermodynamic states in scCO2. The peak frequencies of the Raman spectra of these six solute molecules were analyzed by decomposition into the attractive and repulsive energy components, based on the perturbed hard-sphere theory. For all solute molecules, the attractive energy is greater than the repulsive energy. In particular, a significant difference in the attractive energies of the ester-CO2 and ketone-CO2 systems was observed when the methyl group is attached to the ester or ketone. This difference was significantly reduced in the solute systems with a single phenyl group and was completely absent in those with two phenyl groups. The optimized structures among the solutes and CO2 molecules based on quantum chemical calculations indicate that greater attractive energy is obtained for a system where the oxygen atom of the ester is solvated by CO2 molecules. PMID:26741296

  11. Me2(CH2Cl)SiCN: Bifunctional Cyanating Reagent for the Synthesis of Tertiary Alcohols with a Chloromethyl Ketone Moiety via Ketone Cyanosilylation.

    PubMed

    Zeng, Xing-Ping; Zhou, Jian

    2016-07-20

    We report a novel bifunctional cyanating reagent, Me2(CH2Cl)SiCN, which paves the way to a one-pot sequential synthesis of tertiary alcohols featuring a chloromethyl ketone moiety via enantioselective ketone cyanosilylation. This method contributes to gram-scale enantioselective total synthesis of the aggregation pheromone of the Colorado potato beetle, (S)-CPB. PMID:27399262

  12. Mammalian energetics. Instantaneous energetics of puma kills reveal advantage of felid sneak attacks.

    PubMed

    Williams, Terrie M; Wolfe, Lisa; Davis, Tracy; Kendall, Traci; Richter, Beau; Wang, Yiwei; Bryce, Caleb; Elkaim, Gabriel Hugh; Wilmers, Christopher C

    2014-10-01

    Pumas (Puma concolor) live in diverse, often rugged, complex habitats. The energy they expend for hunting must account for this complexity but is difficult to measure for this and other large, cryptic carnivores. We developed and deployed a physiological SMART (species movement, acceleration, and radio tracking) collar that used accelerometry to continuously monitor energetics, movements, and behavior of free-ranging pumas. This felid species displayed marked individuality in predatory activities, ranging from low-cost sit-and-wait behaviors to constant movements with energetic costs averaging 2.3 times those predicted for running mammals. Pumas reduce these costs by remaining cryptic and precisely matching maximum pouncing force (overall dynamic body acceleration = 5.3 to 16.1g) to prey size. Such instantaneous energetics help to explain why most felids stalk and pounce, and their analysis represents a powerful approach for accurately forecasting resource demands required for survival by large, mobile predators. PMID:25278610

  13. Hypothalamic lipophagy and energetic balance.

    PubMed

    Singh, Rajat

    2011-10-01

    Autophagy is a conserved cellular turnover process that degrades unwanted cytoplasmic material within lysosomes. Through "in bulk" degradation of cytoplasmic proteins and organelles, including lipid droplets, autophagy helps provide an alternative fuel source, in particular, when nutrients are scarce. Recent work demonstrates a role for autophagy in hypothalamic agouti-related peptide (AgRP) neurons in regulation of food intake and energy balance. The induction of autophagy in hypothalamic neurons during starvation mobilizes neuronal neutral lipids to generate neuron-intrinsic free fatty acids that serve to upregulate fasting-induced AgRP levels. Blocking autophagy in AgRP neurons in mice reduces fasting-induced food intake, and increases constitutive levels of anorexigenic hypothalamic proopiomelanocortin and its cleavage product α-melanocyte stimulating hormone. The energetic consequences of these molecular events are decreased body weight and reduced adiposity. The present article discusses this recent finding, as well as considers possible future directions that may help better understand how neuronal autophagy, and its possible reduction during aging, may affect whole body energy balance. PMID:22024462

  14. Energetic component treatability study

    SciTech Connect

    Gildea, P.D.; Brandon, S.L.; Brown, B.G.

    1997-11-01

    The effectiveness of three environmentally sound processes for small energetic component disposal was examined experimentally in this study. The three destruction methods, batch reactor supercritical water oxidation, sodium hydroxide base hydrolysis and calcium carbonate cookoff were selected based on their potential for producing a clean solid residue and minimum release of toxic gases after component detonation. The explosive hazard was destroyed by all three processes. Batch supercritical water oxidation destroyed both the energetics and organics. Further development is desired to optimize process parameters. Sodium hydroxide base hydrolysis and calcium carbonate cookoff results indicated the potential for scrubbing gaseous detonation products. Further study and testing are needed to quantify the effectiveness of these later two processes for full-scale munition destruction. The preliminary experiments completed in this study have demonstrated the promise of these three processes as environmentally sound technologies for energetic component destruction. Continuation of these experimental programs is strongly recommended to optimize batch supercritical water oxidation processing, and to fully develop the sodium hydroxide base hydrolysis and calcium carbonate cookoff technologies.

  15. Rhodium-Catalyzed Ketone Methylation Using Methanol Under Mild Conditions: Formation of α-Branched Products**

    PubMed Central

    Chan, Louis K M; Poole, Darren L; Shen, Di; Healy, Mark P; Donohoe, Timothy J

    2014-01-01

    The rhodium-catalyzed methylation of ketones has been accomplished using methanol as the methylating agent and the hydrogen-borrowing method. The sequence is notable for the relatively low temperatures that are required and for the ability of the reaction system to form α-branched products with ease. Doubly alkylated ketones can be prepared from methyl ketones and two different alcohols by using a sequential one-pot iridium- and rhodium-catalyzed process. PMID:24288297

  16. On the nature of the olefination reaction involving ditungsten hexaalkoxides and aldehydes or ketones

    SciTech Connect

    Chisholm, M.H.; Huffman, J.C.; Lucas, E.A.; Sousa, A.; Streib, W.E.

    1992-03-25

    Reductive coupling of aldehydes and ketones to olefins under the action of ditungsten hexaalkoxides was investigated. In these reactions, reductive cleavage of the aldehyde or ketone carbonyl is followed by formation of the olefinic C-C bond and breaking of the carbonyl C-O bond of the second aldehyde or ketone. Observations concerning the initial C-O bond cleavage and subsequent C-C bond formation are presented. 10 refs., 4 figs.

  17. [Pollution Characteristics of Aldehydes and Ketones Compounds in the Exhaust of Beijing Typical Restaurants].

    PubMed

    Cheng, Jing-chen; Cui, Tong; He, Wan-qing; Nie, Lei; Wang, Jun-ling; Pan, Tao

    2015-08-01

    Aldehydes and ketones compounds, as one of the components in the exhaust of restaurants, are a class of volatile organic compounds (VOCs) with strong chemical reactivity. However, there is no systematic study on aldehydes and ketones compounds in the exhaust of restaurants. To further clarify the food source emission levels of aldehydes and ketones compounds and controlling measures, to access city group catering VOCs emissions control decision-making basis, this study selected 8 Beijing restaurants with different types. The aldehydes and ketones compounds were sampled using DNPH-silica tube, and then ultra performance liquid chromatography was used for quantitative measurement. The aldehydes and ketones concentrations of reference volume condition from 8 restaurants in descending order were Roasted Duck restaurant, Chinese Style Barbecue, Home Dishes, Western Fast-food, School Canteen, Chinese Style Fast-food, Sichuan Cuisine, Huaiyang Cuisine. The results showed that the range of aldehydes and ketones compounds (C1-C9) concentrations of reference volume condition in the exhaust of restaurants was 115.47-1035.99 microg x m(-3). The composition of aldehydes and ketones compounds in the exhaust of sampled restaurants was obviously different. The percentages of C1-C3 were above 40% in the exhaust from Chinese style restaurants. Fast food might emit more C4-C9 aldehydes and ketones compounds. From the current situation of existing aldehydes and ketones compounds control, the removal efficiency of high voltage electrostatic purifiers widely used in Beijing is limited. PMID:26591999

  18. The ketone metabolite β-hydroxybutyrate blocks NLRP3 inflammasome-mediated inflammatory disease.

    PubMed

    Youm, Yun-Hee; Nguyen, Kim Y; Grant, Ryan W; Goldberg, Emily L; Bodogai, Monica; Kim, Dongin; D'Agostino, Dominic; Planavsky, Noah; Lupfer, Christopher; Kanneganti, Thirumala D; Kang, Seokwon; Horvath, Tamas L; Fahmy, Tarek M; Crawford, Peter A; Biragyn, Arya; Alnemri, Emad; Dixit, Vishwa Deep

    2015-03-01

    The ketone bodies β-hydroxybutyrate (BHB) and acetoacetate (AcAc) support mammalian survival during states of energy deficit by serving as alternative sources of ATP. BHB levels are elevated by starvation, caloric restriction, high-intensity exercise, or the low-carbohydrate ketogenic diet. Prolonged fasting reduces inflammation; however, the impact that ketones and other alternative metabolic fuels produced during energy deficits have on the innate immune response is unknown. We report that BHB, but neither AcAc nor the structurally related short-chain fatty acids butyrate and acetate, suppresses activation of the NLRP3 inflammasome in response to urate crystals, ATP and lipotoxic fatty acids. BHB did not inhibit caspase-1 activation in response to pathogens that activate the NLR family, CARD domain containing 4 (NLRC4) or absent in melanoma 2 (AIM2) inflammasome and did not affect non-canonical caspase-11, inflammasome activation. Mechanistically, BHB inhibits the NLRP3 inflammasome by preventing K(+) efflux and reducing ASC oligomerization and speck formation. The inhibitory effects of BHB on NLRP3 are not dependent on chirality or starvation-regulated mechanisms like AMP-activated protein kinase (AMPK), reactive oxygen species (ROS), autophagy or glycolytic inhibition. BHB blocks the NLRP3 inflammasome without undergoing oxidation in the TCA cycle, and independently of uncoupling protein-2 (UCP2), sirtuin-2 (SIRT2), the G protein-coupled receptor GPR109A or hydrocaboxylic acid receptor 2 (HCAR2). BHB reduces NLRP3 inflammasome-mediated interleukin (IL)-1β and IL-18 production in human monocytes. In vivo, BHB or a ketogenic diet attenuates caspase-1 activation and IL-1β secretion in mouse models of NLRP3-mediated diseases such as Muckle-Wells syndrome, familial cold autoinflammatory syndrome and urate crystal-induced peritonitis. Our findings suggest that the anti-inflammatory effects of caloric restriction or ketogenic diets may be linked to BHB

  19. Evaluation of α,β-Unsaturated Ketones as Antileishmanial Agents

    PubMed Central

    Vasquez, Miguel A.; Iniguez, Eva; Das, Umashankar; Beverley, Stephen M.; Herrera, Linda J.; Dimmock, Jonathan R.

    2015-01-01

    In this study, we assessed the antileishmanial activity of 126 α,β-unsaturated ketones. The compounds NC901, NC884, and NC2459 showed high leishmanicidal activity for both the extracellular (50% effective concentration [EC50], 456 nM, 1,122 nM, and 20 nM, respectively) and intracellular (EC50, 1,870 nM, 937 nM, and 625 nM, respectively) forms of Leishmania major propagated in macrophages, with little or no toxicity to mammalian cells. Bioluminescent imaging of parasite replication showed that all three compounds reduced the parasite burden in the murine model, with no apparent toxicity. PMID:25801571

  20. An Iron Catalyst for Ketone Hydrogenations Under Mild Conditions

    SciTech Connect

    Bullock, R. Morris

    2007-10-01

    Casey and Guan reported a homogeneous catalyst for ketone hydrogenation that does not require a precious metal, but instead is based on iron. Excellent yields and chemoselectivity for hydrogenation are found under mild conditions (25 °C, 3 atm H2). An ionic hydrogenation mechanism allows the delivery of a proton from the OH and a hydride from the metal. RMB gratefully acknowledges funding from the Division of Chemical Sciences, Office of Basic Energy Sciences, US Department of Energy, and from a grant from the Laboratory Directed Research and Development Program. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

  1. Asymmetric Propargylation of Ketones using Allenylboronates Catalyzed by Chiral Biphenols

    PubMed Central

    Barnett, David S.; Schaus, Scott E.

    2011-01-01

    Chiral biphenols catalyze the enantioselective asymmetric propargylation of ketones using allenylboronates. The reaction uses 10 mol % of 3,3′-Br2-BINOL as the catalyst and allenyldioxoborolane as the nucleophile, in the absence of solvent, and under microwave irradiation to afford the homopropargylic alcohol. The reaction products are obtained in good yields (60 – 98%) and high enantiomeric ratios (3:1 – 99:1). Diastereoselective propargylations using chiral racemic allenylboronates result in good diastereoselectivities (dr > 86:14) and enantioselectivities (er > 92:8) under the catalytic conditions. PMID:21732609

  2. Asymmetric propargylation of ketones using allenylboronates catalyzed by chiral biphenols.

    PubMed

    Barnett, David S; Schaus, Scott E

    2011-08-01

    Chiral biphenols catalyze the enantioselective asymmetric propargylation of ketones using allenylboronates. The reaction uses 10 mol % of 3,3'-Br(2)-BINOL as the catalyst and allenyldioxoborolane as the nucleophile, in the absence of solvent, and under microwave irradiation to afford the homopropargylic alcohol. The reaction products are obtained in good yields (60-98%) and high enantiomeric ratios (3:1-99:1). Diastereoselective propargylations using chiral racemic allenylboronates result in good diastereoselectivities (dr >86:14) and enantioselectivities (er >92:8) under the catalytic conditions. PMID:21732609

  3. Effects of trifluoromethyl ketones on the motility of Proteus vulgaris.

    PubMed

    Wolfart, Krisztina; Molnar, Annamaria; Kawase, Masami; Motohashi, Noboru; Molnar, Joseph

    2004-09-01

    In the present study, we showed the inhibition of motility by trifluoromethyl ketone (TF) derivatives (1-8) in Proteus vulgaris (P. vulgaris) cultures. Among them, 1-(2-benzoxazoyl)-3,3,3-trifluoro-2-propanone (1) showed a much stronger inhibitory effect on the motility of P. vulgaris than other TF compounds at 10% MIC. Our results suggest the possibility of an inhibitory action of TF compounds on the proton motive forces by affecting the action of biological motor and proton efflux in the membranes, resulting in a reduction of the ratio of running and the increased number of tumbling and non-motile cells. PMID:15340240

  4. Copper-catalyzed asymmetric hydrogenation of aryl and heteroaryl ketones.

    PubMed

    Krabbe, Scott W; Hatcher, Mark A; Bowman, Roy K; Mitchell, Mark B; McClure, Michael S; Johnson, Jeffrey S

    2013-09-01

    High throughput screening enabled the development of a Cu-based catalyst system for the asymmetric hydrogenation of prochiral aryl and heteroaryl ketones that operates at H2 pressures as low as 5 bar. A ligand combination of (R,S)-N-Me-3,5-xylyl-BoPhoz and tris(3,5-xylyl)phosphine provided benzylic alcohols in good yields and enantioselectivities. The electronic and steric characteristics of the ancillary triarylphosphine were important in determining both reactivity and selectivity. PMID:23980941

  5. Nonadiabatic reaction of energetic molecules.

    PubMed

    Bhattacharya, Atanu; Guo, Yuanqing; Bernstein, Elliot R

    2010-12-21

    Energetic materials store a large amount of chemical energy that can be readily converted into mechanical energy via decomposition. A number of different ignition processes such as sparks, shocks, heat, or arcs can initiate the excited electronic state decomposition of energetic materials. Experiments have demonstrated the essential role of excited electronic state decomposition in the energy conversion process. A full understanding of the mechanisms for the decomposition of energetic materials from excited electronic states will require the investigation and analysis of the specific topography of the excited electronic potential energy surfaces (PESs) of these molecules. The crossing of multidimensional electronic PESs creates a funnel-like topography, known as conical intersections (CIs). CIs are well established as a controlling factor in the excited electronic state decomposition of polyatomic molecules. This Account summarizes our current understanding of the nonadiabatic unimolecular chemistry of energetic materials through CIs and presents the essential role of CIs in the determination of decomposition pathways of these energetic systems. Because of the involvement of more than one PES, a decomposition process involving CIs is an electronically nonadiabatic mechanism. Based on our experimental observations and theoretical calculations, we find that a nonadiabatic reaction through CIs dominates the initial decomposition process of energetic materials from excited electronic states. Although the nonadiabatic behavior of some polyatomic molecules has been well studied, the role of nonadiabatic reactions in the excited electronic state decomposition of energetic molecules has not been well investigated. We use both nanosecond energy-resolved and femtosecond time-resolved spectroscopic techniques to determine the decomposition mechanism and dynamics of energetic species experimentally. Subsequently, we employ multiconfigurational methodologies (such as, CASSCF

  6. Synthesis, conformational parameters and packing considerations of methyl bispyridyl ketones

    NASA Astrophysics Data System (ADS)

    Weck, Christian; Katzsch, Felix; Gruber, Tobias

    2015-10-01

    The crystal structures of two bispyridyl ketones featuring either two methyl residues or one methyl and one bromomethyl residue, respectively, are presented. In order to elucidate the influence of the substituents, a comprehensive comparison with the non-methylated mother compound has been performed. A special focus lies thereby on the relative position of the heteroatoms and their free electron pairs. The two methyl groups at the bispyridyl ketone result in two molecules in the asymmetric unit adopting rather different conformations. Due to the fast crystallization conditions and a melting point differing from the literature, a polymorph close to a local minimum in the energy hypersurface seems possible. After introducing a bromine atom to one of the two methyl groups, the molecular conformation is very similar to the unsubstituted molecule. The packing of both title compounds is dominated by weak contacts of the C-H⋯π and C-H⋯Y type (Y = O, N) and C-H⋯Br- and Br⋯π-contacts for the brominated molecule.

  7. Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria.

    PubMed

    Heider, Johann; Schühle, Karola; Frey, Jasmin; Schink, Bernhard

    2016-01-01

    Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO2-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions. PMID:26958851

  8. Overview on energetic polymers

    SciTech Connect

    Boileau, J.

    1996-07-01

    Energetic materials for missiles, gun munitions or pyrotechnic devices often are mixtures in a biphasic form, with a filler and a binder. To satisfy the user needs, an analysis of functional requirements together with constraints (safety, vulnerability, aging, environment, disposal, price) is useful to choose a convenient binder. From this point of view numerous synthetic energetic polymers proposed or developed as binders are reviewed with regard to their syntheses, processing, properties and possible uses. These polymers contain explosophore groups: C-NO{sub 2} aliphatic or aromatic, ONO{sub 2}, NNO{sub 2}, NF{sub 2} and N{sub 3}. Some research projects are suggested. Among them in the list of published polymers, following a NIMIC (NATO) suggestion, note the reason of a development interruption. Some dinitropolystyrene-polyvinyl nitrate mixtures or copolymers could exhibit interesting properties. For unknown reasons, some mixtures of crystalline filler with polymer binder, generally in a biphasic form, may also be monophasic for a same composition. What properties are modified between both forms (e.g. combustion mechanisms, erosion, ideal character of the detonation)? It is also interesting to pursue a newly open route to thermo-plastic elastomers. 50 refs., 1 tab.

  9. Energetics of Nanomaterials

    SciTech Connect

    Alexandra Navrotsky; Brian Woodfield; Juliana Boerio-Goates; Frances Hellman

    2005-01-28

    This project, "Energetics of Nanomaterials," represents a three-year collaboration among Alexandra Navrotsky (UC Davis), Brian Woodfield and Juliana Boerio-Goates (BYU), and Frances Hellman (UC Berkeley). It's purpose has been to explore the differences between bulk materials, nanoparticles, and thin films in term of their thermodynamic properties, with an emphasis on heat capaacities and entropies, as well as enthalpies. the three groups have brought very different expertise and capabilities to the project. Navrotsky is a solid-state chemist and geochemist, with a unique Thermochemistry Facility emphasizing enthalpy of formation measurements by high temperature oxide melt and room temperatue acid solution calorimetry. Boerio-Goates and Woodfield are calorimetry. Hellman is a physicist with expertise in magnetism and heat capacity measurements using microscale "detector on a chip" calorimetric technology that she pioneered. The overarching question of our work is "How does the free energy play out in nanoparticles?", or "How do differences in free energy affect overall nanoparticle behavior?" Because the free energy represents the temperature-dependent balance between the enthalpy of a system and its entropy, there are two separate, but related, components to the experimental investigations: Solution calorimetric measurements provide the energetics and two types of heat capacity measurements the entropy. We use materials that are well characterized in other ways (structurally, magnetically, and chemically), and samples are shared across the collaboration.

  10. Energetic consequences of being a Homo erectus female.

    PubMed

    Aiello, Leslie C; Key, Cathy

    2002-01-01

    Body size is one of the most important characteristics of any animal because it affects a range of behavioral, ecological, and physiological traits including energy requirements, choice of food, reproductive strategies, predation risk, range size, and locomotor style. This article focuses on the implications of being large bodied for Homo erectus females, estimated to have been over 50% heavier than average australopithecine females. The energy requirements of these hominins are modeled using data on activity patterns, body mass, and life history from living primates. Particular attention is given to the inferred energetic costs of reproduction for Homo erectus females based on chimpanzee and human reproductive scheduling. Daily energy requirements during gestation and lactation would have been significantly higher for Homo erectus females, as would total energetic cost per offspring if the australopithecines and Homo erectus had similar reproductive schedules (gestation and lactation lengths and interbirth intervals). Shortening the interbirth interval could considerably reduce the costs per offspring to Homo erectus and have the added advantage of increasing reproductive output. The mother would, however, incur additional daily costs of caring for the dependent offspring. If Homo erectus females adopted this reproductive strategy, it would necessarily imply a revolution in the way in which females obtained and utilized energy to support their increased energetic requirements. This transformation is likely to have occurred on several levels involving cooperative economic division of labor, locomotor energetics, menopause, organ size, and other physiological mechanisms for reducing the energetic load on females. PMID:12203811

  11. Enantioselective Reduction of Ketones and Imines Catalyzed by (CN-Box)Re(V)-Oxo Complexes

    PubMed Central

    Nolin, Kristine A.; Ahn, Richard W.; Kobayashi, Yusuke; Kennedy-Smith, Joshua J.

    2012-01-01

    The development and application of chiral, non-racemic Re(V)-oxo complexes to the enantioselective reduction of prochiral ketones is described. In addition to the enantioselective reduction of prochiral ketones, we report the application of these complexes to (1) a tandem Meyer-Schuster rearrangement/reduction to access enantioenriched allylic alcohols and (2) the enantioselective reduction of imines. PMID:20623567

  12. Raspberry Ketone Trifluoroacetate, a new attractant for the Queensland fruit fly (Bactrocera tryoni (Froggatt))

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Queensland fruit fly (Bactrocera tryoni, Q-fly) is a major agricultural pest in eastern Australia. The deployment of male lures comprises an important component of several control and detection strategies for this pest. A novel fluorinated analog of raspberry ketone, raspberry ketone trifluoroac...

  13. Further research on the biological activities and the safety of raspberry ketone are needed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Raspberry ketone supplements have grabbed consumer attention with the possibility they might help burn fat and aid weight loss. While raspberry ketone occurs naturally, and is found in raspberry fruit, most is synthetically produced for use in commercial products as flavorings, fragrances, or dietar...

  14. Visible-Light Induced Direct Synthesis of Polysubstituted Furans from Cyclopropyl Ketones.

    PubMed

    Feng, Liyan; Yan, Hang; Yang, Chao; Chen, Dafa; Xia, Wujiong

    2016-08-19

    In this article, a photoredox protocol for the synthesis of furans via oxidative coupling of olefin generated in situ from cyclopropyl ketones with ketonic oxygen atom is presented. Moreover, bromination of furans in the presence of overstoichiometric oxidant has been achieved with high regioselectivity. PMID:27167091

  15. 40 CFR 721.10413 - Fluorinated dialkyl ketone (generic) (P-10-135).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) (P-10-135). 721.10413 Section 721.10413 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10413 Fluorinated dialkyl ketone (generic) (P-10-135). (a) Chemical... as fluorinated dialkyl ketone (PMN P-10-135) is subject to reporting under this section for...

  16. 40 CFR 721.10417 - Biphenyl alkyl morpholino ketone (generic) (P-11-338).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (generic) (P-11-338). 721.10417 Section 721.10417 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10417 Biphenyl alkyl morpholino ketone (generic) (P-11-338). (a... generically as biphenyl alkyl morpholino ketone (PMN P-11-338) is subject to reporting under this section...

  17. 40 CFR 721.10413 - Fluorinated dialkyl ketone (generic) (P-10-135).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) (P-10-135). 721.10413 Section 721.10413 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10413 Fluorinated dialkyl ketone (generic) (P-10-135). (a) Chemical... as fluorinated dialkyl ketone (PMN P-10-135) is subject to reporting under this section for...

  18. 40 CFR 721.10413 - Fluorinated dialkyl ketone (generic) (P-10-135).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) (P-10-135). 721.10413 Section 721.10413 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10413 Fluorinated dialkyl ketone (generic) (P-10-135). (a) Chemical... as fluorinated dialkyl ketone (PMN P-10-135) is subject to reporting under this section for...

  19. 40 CFR 721.10417 - Biphenyl alkyl morpholino ketone (generic) (P-11-338).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (generic) (P-11-338). 721.10417 Section 721.10417 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10417 Biphenyl alkyl morpholino ketone (generic) (P-11-338). (a... generically as biphenyl alkyl morpholino ketone (PMN P-11-338) is subject to reporting under this section...

  20. 40 CFR 721.10417 - Biphenyl alkyl morpholino ketone (generic) (P-11-338).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (generic) (P-11-338). 721.10417 Section 721.10417 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10417 Biphenyl alkyl morpholino ketone (generic) (P-11-338). (a... generically as biphenyl alkyl morpholino ketone (PMN P-11-338) is subject to reporting under this section...

  1. Beyond ketonization: selective conversion of carboxylic acids to olefins over balanced Lewis acid-base pairs.

    PubMed

    Baylon, Rebecca A L; Sun, Junming; Martin, Kevin J; Venkitasubramanian, Padmesh; Wang, Yong

    2016-04-11

    We report the direct conversion of mixed carboxylic acids to C-C olefins with up to 60 mol% carbon yield through cascade (cross) ketonization, (cross) aldolization and self-deoxygenation reactions. Co-feeding hydrogen provides an additional ketone hydrogenation/dehydration pathway to a wider range of olefins. PMID:26898532

  2. Proton-exchange membrane materials based on blends of poly(ether ketone ketone) and poly(ether imide)

    NASA Astrophysics Data System (ADS)

    Swier, S.; Gasa, J.; Shaw, M. T.; Weiss, R. A.

    2004-03-01

    The development of materials for proton-exchange membranes (PEM) involves finding a compromise between high proton conductivities and sufficient mechanical and chemical stability to withstand the conditions in the fuel cell. The currently used perfluorinated polymer electrolyte membranes tend to be expensive and have problems in case of extensive application. New polymer electrolytes based on hydrocarbon polymers are therefore the focus of a considerable research effort. Blends of sulfonated poly(ether ketone ketone) (SPEKK) and poly(ether imide) (PEI) were evaluated as PEMs. Sulfonation of PEKK was achieved by using a mixture of concentrated sulfuric acid and fuming sulfuric acid, and blend membranes were prepared by casting a solution of the two polymers in N-methyl-2- pyrrolidone. The hydration level of the membrane decreased with increasing PEI concentration, but a proton conductivity comparable to NafionTM was obtained for blends containing less than 20 wt% PEI. The fuel cell performance of the membranes was affected by the sulfonation level of the PEKK, the blend composition and the casting procedure employed. The state of water in the membrane was evaluated from the depression of the glass transition and from the melting endotherms associated with water. Proton conductivity depended strongly on the hydration number (water molecules per sulfonate group), which depended on the sulfonation level of the PEKK and the blend morphology. Sorption data from gravimetric techniques provided important transport information like the solubility and diffusivity of water and methanol.

  3. Interfacial interactions of poly(ether ketone ketone) polymer coatings onto oxide-free phosphate films on an aluminum surface

    SciTech Connect

    Asunskis, A. L.; Sherwood, P. M. A.

    2007-07-15

    This article continues a series of papers that shows how thin (10 nm or less) oxide-free phosphate films can be formed on a number of metals. The films formed have potential as corrosion resistant films. Previous papers have shown that it is possible to extend the range of the surface coatings that can be formed by placing a thin polymer layer over the phosphate layer. In this work it is shown how the water insoluble polymer poly(ether ketone ketone) (PEKK) can be placed over a thin oxide-free phosphate film on aluminum metal. The surface and the interfaces involved were studied by valence band and core level x-ray photoelectron spectroscopy. Difference spectra in the valence band region were used to show that there is a chemical interaction between the PEKK and phosphate thin films on the aluminum metal. Three different phosphate film compositions were studied using different phosphorous containing acids, H{sub 3}PO{sub 4}, H{sub 3}PO{sub 3}, and H{sub 3}PO{sub 2}. This type of interaction illustrates the potential of phosphates to act as adhesion promoters. The valence band spectra are interpreted by calculations.

  4. Can a Shift in Fuel Energetics Explain the Beneficial Cardiorenal Outcomes in the EMPA-REG OUTCOME Study? A Unifying Hypothesis.

    PubMed

    Mudaliar, Sunder; Alloju, Sindura; Henry, Robert R

    2016-07-01

    Type 2 diabetes mellitus causes excessive morbidity and premature cardiovascular (CV) mortality. Although tight glycemic control improves microvascular complications, its effects on macrovascular complications are unclear. The recent publication of the EMPA-REG OUTCOME study documenting impressive benefits with empagliflozin (a sodium-glucose cotransporter 2 [SGLT2] inhibitor) on CV and all-cause mortality and hospitalization for heart failure without any effects on classic atherothrombotic events is puzzling. More puzzling is that the curves for heart failure hospitalization, renal outcomes, and CV mortality begin to separate widely within 3 months and are maintained for >3 years. Modest improvements in glycemic, lipid, or blood pressure control unlikely contributed significantly to the beneficial cardiorenal outcomes within 3 months. Other known effects of SGLT2 inhibitors on visceral adiposity, vascular endothelium, natriuresis, and neurohormonal mechanisms are also unlikely major contributors to the CV/renal benefits. We postulate that the cardiorenal benefits of empagliflozin are due to a shift in myocardial and renal fuel metabolism away from fat and glucose oxidation, which are energy inefficient in the setting of the type 2 diabetic heart and kidney, toward an energy-efficient super fuel like ketone bodies, which improve myocardial/renal work efficiency and function. Even small beneficial changes in energetics minute to minute translate into large differences in efficiency, and improved cardiorenal outcomes over weeks to months continue to be sustained. Well-planned physiologic and imaging studies need to be done to characterize fuel energetics-based mechanisms for the CV/renal benefits. PMID:27289124

  5. Utilization of FEP energetics

    NASA Technical Reports Server (NTRS)

    Frederking, T. H. K.; Abbassi, P.; Afifi, F.; Khandhar, P. K.; Ono, D. Y.; Chen, W. E. W.

    1987-01-01

    The research and development work on Fountain Effect Pump Systems (FEP systems) has been of interest in the competition between mechanical pumps for He II and FEP units. The latter do not have moving parts. In the course of the work, the energetics have been addressed using one part of a simple four-changes-of-state cycle. One option is the FEP ideal change of state at constant chemical potential (mu). The other option is the two-state sequence mu-P with a d mu=0 state change followed by an isobar. Questions of pump behavior, of flow rate response to temperature difference at the hot end, and related questions of thermodynamic cycle completion and heat transfer have been addressed. Porous media data obtained elucidate differences between vapor-liquid phase separation (VLPS) and Zero Net Mass Transfer (ZNMF).

  6. Energetics of Nanomaterials

    SciTech Connect

    Hellman, Frances

    2004-12-13

    This project, ''Energetics of Nanomaterials'', represents a three-year collaboration among Alexandra Navrotsky (University of California at Davis), Brian Woodfield and Juliana Boerio-Goates (Brigham Young University) and Frances Hellman (University of California at San Diego). Its purpose has been to explore the differences between bulk materials, nanoparticles, and thin films in terms of their thermodynamic properties, with an emphasis on heat capacities and entropies, as well as enthalpies. We used our combined experimental techniques to address the following questions: How does energy and entropy depend on particle size and crystal structure? Do entropic differences have their origins in changes in vibrational densities of states or configurational (including surface configuration) effects? Do material preparation and sample geometry, i.e., nanoparticles versus thin films, change these quantities? How do the thermodynamics of magnetic and structural transitions change in nanoparticles and thin films? Are different crystal structures stabilized for a given composition at the nanoscale, and are the responsible factors energetic, entropic, or both? How do adsorption energies (for water and other gases) depend on particle size and crystal structure in the nanoregime? What are the energetics of formation and strain energies in artificially layered thin films? Do the differing structures of grain boundaries in films and nanocomposites alter the energetics of nanoscale materials? Of the several directions we first proposed, we initially concentrated on a few systems: TiO(sub 2), CoO, and CoO-MgO. In these systems, we were able to clearly identify particle size-dependent effects on energy and vibrational entropy, and to separate out the effect of particle size and water content on the enthalpy of formation of the various TiO(sub 2) polymorphs. With CoO, we were able to directly compare nanoparticle films and bulk materials; this comparison is important because films can

  7. Energetics and systems

    SciTech Connect

    Mitsch, W.J.; Ragade, R.K.; Bosserman, R.W.; Dillon, J.A. Jr.

    1982-01-01

    To those wrestling with environmental problems and those involved with the holistic approaches of general-systems research, energy must be approached from a variety of viewpoints, some with immediate pragmatic connotations, some with long-term scientific and philosophical implications. During April 1981, there were held in Louisville, Kentucky under the auspices of the Systems Science Institute of the University of Louisville, meetings of the International Society for Ecological Modelling and the Society for General Systems Research, Southeast Region. On Earth Day, April 22, a joint symposium of the two societies was held under the title, Energetics and Systems. A number of the foremost researchers in this broad field were involved in that symposium, and the material of this volume is based on those presentations. The first chapter was devoted to introduction and overview; a separate abstract was prepared for each of the other 7 chapters.

  8. The rotational spectrum of Roesky’s ketone

    NASA Astrophysics Data System (ADS)

    Blockhuys, Frank; Tersago, Karla; Shlykov, Sergey A.; Konrad, Alexander; Christen, Dines

    2010-08-01

    The experimental rotational spectrum of 5-oxo-1,3,2,4-dithiadiazole (Roesky's ketone) has been recorded and the experimental rotational constants have been determined. The latter have been used to evaluate the performance of a large number of quantum chemical methods combined with different basis sets, by comparing the calculated with the experimental values. The results of this comparison indicate that, in general, the wave-function-based methods perform better than those from Density Functional Theory. Four of the 42 investigated method/basis set combinations prove to be the most valuable, i.e., MP4(SDQ)/(aug-)cc-pVTZ, B3PW91/cc-pV(T+d)Z and MPW1PW91/aug-cc-pVTZ, as they produce rotational constants with a root-mean-square deviation from the experimental values of only about 5 MHz.

  9. Electron impact ionization of cycloalkanes, aldehydes, and ketones

    SciTech Connect

    Gupta, Dhanoj; Antony, Bobby

    2014-08-07

    The theoretical calculations of electron impact total ionization cross section for cycloalkane, aldehyde, and ketone group molecules are undertaken from ionization threshold to 2 keV. The present calculations are based on the spherical complex optical potential formalism and complex scattering potential ionization contribution method. The results of most of the targets studied compare fairly well with the recent measurements, wherever available and the cross sections for many targets are predicted for the first time. The correlation between the peak of ionization cross sections with number of target electrons and target parameters is also reported. It was found that the cross sections at their maximum depend linearly with the number of target electrons and with other target parameters, confirming the consistency of the values reported here.

  10. Electrical initiation of an energetic nanolaminate film

    DOEpatents

    Tringe, Joseph W.; Gash, Alexander E.; Barbee, Jr., Troy W.

    2010-03-30

    A heating apparatus comprising an energetic nanolaminate film that produces heat when initiated, a power source that provides an electric current, and a control that initiates the energetic nanolaminate film by directing the electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature. Also a method of heating comprising providing an energetic nanolaminate film that produces heat when initiated, and initiating the energetic nanolaminate film by directing an electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature.

  11. Synthesis of Advanced Energetic Materials

    NASA Astrophysics Data System (ADS)

    Wilson, Rebecca

    2015-06-01

    For a given energetic material, performance is a combination of the rate of energy release and total energy content. Organic and metal-based energetics, respectively, represent the limiting cases, exhibiting strength in one area and weakness in the other. Many organic energetic materials readily detonate, but increasing total energy content using only known energetic functional groups is difficult. In contrast, combustion of aluminum metal can release more than three times the energy available from the same mass of organic explosive, but the rate of energy release is slow relative to detonation, and combustion is often incomplete. Current research in our department seeks to improve both the total energy content of organic explosives and the rate of combustion of aluminum-based materials. Novel arrangements of atoms within energetic molecules, along with new assembly methods for materials, are employed to improve both aspects of performance. In the case of organic energetic materials, novel functional groups can yield compounds with higher density, and therefore greater power, relative to conventional, nitro group-based materials. For aluminum-based materials, progressively smaller particles undergo more rapid and complete combustion. To prevent surface oxidation, one approach is to shield a core of low-valent aluminum atoms with a shell of ligands, while another is to develop aluminum-based fuels that are inherently air-stable. These methods will be discussed in the context of novel energetic materials synthesis. Research Department, NSWC IHEODTD.

  12. Low temperature (550-700 K) oxidation pathways of cyclic ketones: dominance of HO2-elimination channels yielding conjugated cyclic coproducts.

    PubMed

    Scheer, Adam M; Welz, Oliver; Vasu, Subith S; Osborn, David L; Taatjes, Craig A

    2015-05-14

    The low-temperature oxidation of three cyclic ketones, cyclopentanone (CPO; C5H8=O), cyclohexanone (CHO; C6H10=O), and 2-methyl-cyclopentanone (2-Me-CPO; CH3-C5H7=O), is studied between 550 and 700 K and at 4 or 8 Torr total pressure. Initial fuel radicals R are formed via fast H-abstraction from the ketones by laser-photolytically generated chlorine atoms. Intermediates and products from the subsequent reactions of these radicals in the presence of excess O2 are probed with time and isomeric resolution using multiplexed photoionization mass spectrometry with tunable synchrotron ionizing radiation. For CPO and CHO the dominant product channel in the R + O2 reactions is chain-terminating HO2-elimination yielding the conjugated cyclic coproducts 2-cyclopentenone and 2-cyclohexenone, respectively. Results on oxidation of 2-Me-CPO also show a dominant contribution from HO2-elimination. The photoionization spectrum of the co-product suggests formation of 2-methyl-2-cyclopentenone and/or 2-cyclohexenone, resulting from a rapid Dowd-Beckwith rearrangement, preceding addition to O2, of the initial (2-oxocyclopentyl)methyl radical to 3-oxocyclohexyl. Cyclic ethers, markers for hydroperoxyalkyl radicals (QOOH), key intermediates in chain-propagating and chain-branching low-temperature combustion pathways, are only minor products. The interpretation of the experimental results is supported by stationary point calculations on the potential energy surfaces of the associated R + O2 reactions at the CBS-QB3 level. The calculations indicate that HO2-elimination channels are energetically favored and product formation via QOOH is disfavored. The prominence of chain-terminating pathways linked with HO2 formation in low-temperature oxidation of cyclic ketones suggests little low-temperature reactivity of these species as fuels in internal combustion engines. PMID:25877515

  13. Low temperature (550-700 K) oxidation pathways of cyclic ketones: Dominance of HO2-elimination channels yielding conjugated cyclic coproducts

    DOE PAGESBeta

    Scheer, Adam M.; Welz, Oliver; Vasu, Subith S.; Osborn, David L.; Taatjes, Craig A.

    2015-04-13

    The low-temperature oxidation of three cyclic ketones, cyclopentanone (CPO; C5H8O), cyclohexanone (CHO; C6H10 O), and 2-methyl-cyclopentanone (2-Me-CPO; CH3–C5H7 O), is studied between 550 and 700 K and at 4 or 8 Torr total pressure. Initial fuel radicals R are formedvia fast H-abstraction from the ketones by laser-photolytically generated chlorine atoms. Intermediates and products from the subsequent reactions of these radicals in the presence of excess O2 are probed with time and isomeric resolution using multiplexed photoionization mass spectrometry with tunable synchrotron ionizing radiation. For CPO and CHO the dominant product channel in the R + O2 reactions is chain-terminating HO2-eliminationmore » yielding the conjugated cyclic coproducts 2-cyclopentenone and 2-cyclohexenone, respectively. Results on oxidation of 2-Me-CPO also show a dominant contribution from HO2-elimination. Moreover, the photoionization spectrum of the co-product suggests formation of 2-methyl-2-cyclopentenone and/or 2-cyclohexenone, resulting from a rapid Dowd–Beckwith rearrangement, preceding addition to O2, of the initial (2-oxocyclopentyl)methyl radical to 3-oxocyclohexyl. Cyclic ethers, markers for hydroperoxyalkyl radicals (QOOH), key intermediates in chain-propagating and chain-branching low-temperature combustion pathways, are only minor products. The interpretation of the experimental results is supported by stationary point calculations on the potential energy surfaces of the associated R + O2 reactions at the CBS-QB3 level. Furthermore, the calculations indicate that HO2-elimination channels are energetically favored and product formation via QOOH is disfavored. Lastly, the prominence of chain-terminating pathways linked with HO2 formation in low-temperature oxidation of cyclic ketones suggests little low-temperature reactivity of these species as fuels in internal combustion engines.« less

  14. Homogenization and lipase treatment of milk and resulting methyl ketone generation in blue cheese.

    PubMed

    Cao, Mingkai; Fonseca, Leorges M; Schoenfuss, Tonya C; Rankin, Scott A

    2014-06-25

    A specific range of methyl ketones contribute to the distinctive flavor of traditional blue cheeses. These ketones are metabolites of lipid metabolism by Penicillium mold added to cheese for this purpose. Two processes, namely, the homogenization of milk fat and the addition of exogenous lipase enzymes, are traditionally applied measures to control the formation of methyl ketones in blue cheese. There exists little scientific validation of the actual effects of these treatments on methyl ketone development. The present study evaluated the effects of milk fat homogenization and lipase treatments on methyl ketone and free fatty acid development using sensory methods and the comparison of selected volatile quantities using gas chromatography. Initial work was conducted using a blue cheese system model; subsequent work was conducted with manufactured blue cheese. In general, there were modest effects of homogenization and lipase treatments on free fatty acid (FFA) and methyl ketone concentrations in blue cheese. Blue cheese treatments involving Penicillium roqueforti lipase with homogenized milk yielded higher FFA and methyl ketone levels, for example, a ∼20-fold increase for hexanoic acid and a 3-fold increase in 2-pentanone. PMID:24460517

  15. Stab Sensitivity of Energetic Nanolaminates

    SciTech Connect

    Gash, A; Barbee, T; Cervantes, O

    2006-05-22

    This work details the stab ignition, small-scale safety, and energy release characteristics of bimetallic Al/Ni(V) and Al/Monel energetic nanolaminate freestanding thin films. The influence of the engineered nanostructural features of the energetic multilayers is correlated with both stab initiation and small-scale energetic materials testing results. Structural parameters of the energetic thin films found to be important include the bi-layer period, total thickness of the film, and presence or absence of aluminum coating layers. In general the most sensitive nanolaminates were those that were relatively thick, possessed fine bi-layer periods, and were not coated. Energetic nanolaminates were tested for their stab sensitivity as freestanding continuous parts and as coarse powders. The stab sensitivity of mock M55 detonators loaded with energetic nanolaminate was found to depend strongly upon both the particle size of the material and the configuration of nanolaminate material, in the detonator cup. In these instances stab ignition was observed with input energies as low as 5 mJ for a coarse powder with an average particle dimension of 400 {micro}m. Selected experiments indicate that the reacting nanolaminate can be used to ignite other energetic materials such as sol-gel nanostructured thermite, and conventional thermite that was either coated onto the multilayer substrate or pressed on it. These results demonstrate that energetic nanolaminates can be tuned to have precise and controlled ignition thresholds and can initiate other energetic materials and therefore are viable candidates as lead-free impact initiated igniters or detonators.

  16. Adaptive mechanisms regulate preferred utilization of ketones in the heart and brain of a hibernating mammal during arousal from torpor

    PubMed Central

    Andrews, Matthew T.; Russeth, Kevin P.; Drewes, Lester R.; Henry, Pierre-Gilles

    2009-01-01

    Hibernating mammals use reduced metabolism, hypothermia, and stored fat to survive up to 5 or 6 mo without feeding. We found serum levels of the fat-derived ketone, d-β-hydroxybutyrate (BHB), are highest during deep torpor and exist in a reciprocal relationship with glucose throughout the hibernation season in the thirteen-lined ground squirrel (Spermophilus tridecemlineatus). Ketone transporter monocarboxylic acid transporter 1 (MCT1) is upregulated at the blood-brain barrier, as animals enter hibernation. Uptake and metabolism of 13C-labeled BHB and glucose were measured by high-resolution NMR in both brain and heart at several different body temperatures ranging from 7 to 38°C. We show that BHB and glucose enter the heart and brain under conditions of depressed body temperature and heart rate but that their utilization as a fuel is highly selective. During arousal from torpor, glucose enters the brain over a wide range of body temperatures, but metabolism is minimal, as only low levels of labeled metabolites are detected. This is in contrast to BHB, which not only enters the brain but is also metabolized via the tricarboxylic acid (TCA) cycle. A similar situation is seen in the heart as both glucose and BHB are transported into the organ, but only 13C from BHB enters the TCA cycle. This finding suggests that fuel selection is controlled at the level of individual metabolic pathways and that seasonally induced adaptive mechanisms give rise to the strategic utilization of BHB during hibernation. PMID:19052316

  17. A new alternative to expandable pedicle screws: Expandable poly-ether-ether-ketone shell.

    PubMed

    Demir, Teyfik

    2015-05-01

    Screw pullout is a very common problem in the fixation of sacrum with pedicle screws. The principal cause of this problem is that the cyclic micro motions in the fixation of sacrum are higher than the other regions of the vertebrae that limit the osteo-integration between bone and screw. In addition to that, the bone quality is very poor at sacrum region. This study investigated a possible solution to the pullout problem without the expandable screws' handicaps. Newly designed poly-ether-ether-ketone expandable shell and classical pedicle screws were biomechanically compared. Torsion test, pullout tests, fatigue tests, flexion/extension moment test, axial gripping capacity tests and torsional gripping capacity tests were conducted in accordance with ASTM F543, F1798 and F1717. Standard polyurethane foam and calf vertebrae were used as embedding medium for pullout tests. Classical pedicle screw pullout load on polyurethane foam was 564.8 N compared to the failure load for calf vertebrae's 1264 N. Under the same test conditions, expandable poly-ether-ether-ketone shell system's pullout loads from polyurethane foam and calf vertebrae were 1196.3 and 1890 N, respectively. The pullout values for expandable poly-ether-ether-ketone shell were 33% and 53% higher than classical pedicle screw on polyurethane foam and calf vertebrae, respectively. The expandable poly-ether-ether-ketone shell exhibited endurance on its 90% of yield load. Contrary to poly-ether-ether-ketone shell, classical pedicle screw exhibited endurance on 70% of its yield load. Expandable poly-ether-ether-ketone shell exhibited much higher pullout performance than classical pedicle screw. Fatigue performance of expandable poly-ether-ether-ketone shell is also higher than classical pedicle screw due to damping the micro motion capacity of the poly-ether-ether-ketone. Expandable poly-ether-ether-ketone shell is a safe alternative to all other expandable pedicle screw systems on mechanical perspective

  18. Intermolecular reductive coupling of esters with benzophenones by low-valent titanium: synthesis of diarylmethyl ketones revisited.

    PubMed

    Kise, Naoki; Sakurai, Toshihiko

    2015-04-01

    The reductive coupling of aliphatic esters with benzophenones by Zn-TiCl4 in THF gave two- and four-electron reduced products, diaryl(hydroxy)methyl ketones, and diarylmethyl ketones selectively by controlling the reaction conditions. In the reaction of aromatic esters with benzophenones, diarylmethyl ketones were obtained as the sole products. N-(Alkoxycarbonyl)-(S)-α-amino acid methyl esters gave optically active diphenylmethyl ketones by reduction with benzophenone. The obtained diphenylmethyl ketones were transformed to 4,5-cis-disubstituted oxazolidin-2-ones stereoselectively. PMID:25748528

  19. Energetic spacetime: the new aether

    NASA Astrophysics Data System (ADS)

    Macken, John A.

    2015-09-01

    A model of the universe based on energetic spacetime (zero point energy) is expanded. The energy density of spacetime is calculated using only general relativity and acoustic equations. This energetic spacetime is shown to possess the properties required to be the new aether (Lorentz invariance, quantization of angular momentum, impedance, and quantum mechanical energy density.) The contradictory wave-particle duality properties of a photon are resolved by a model where a photon is a wave propagating in energetic spacetime but appearing to have particle properties because it possesses quantized angular momentum. Compton scattering and the photoelectric effect are examined and found to be compatible with the proposed wave-based photon model.

  20. Energetic particles at Uranus

    NASA Technical Reports Server (NTRS)

    Cheng, Andrew F.; Krimigis, S. M.; Lanzerotti, L. J.

    1991-01-01

    The energetic particle measurements by the low-energy charged-particle and cosmic-ray instruments on the Voyager 2 spacecraft in the magnetosphere of Uranus are reviewed. Upstream events were observed outside the Uranian bow shock, probably produced by ion escape from the magnetosphere. Evidence of earthlike substorm activity was discovered within the Uranian magnetosphere. A proton injection event was observed within the orbit of Umbriel and proton events were observed in the magnetotail plasma-sheet boundary layer that are diagnostic of earthlike substorms. The magnetospheric composition is totally dominated by protons, with only a trace abundance of H(2+) and no evidence for He or heavy ions; the Uranian atmophere is argued to be the principal plasma source. Phase-space densities of medium energy protons show inward radial diffusion and are quantitatively similar to those observed at the earth, Jupiter, and Saturn. These findings and plasma wave data suggest the existence of structures analogous to the earth's plasmasphere and plasmapause.

  1. ENERGETICS, EPIGENETICS, MITOCHONDRIAL GENETICS

    PubMed Central

    Wallace, Douglas C.; Fan, Weiwei

    2011-01-01

    The epigenome has been hypothesized to provide the interface between the environment and the nuclear DNA (nDNA) genes. Key factors in the environment are the availability of calories and demands on the organism’s energetic capacity. Energy is funneled through glycolysis and mitochondrial oxidative phosphorylation (OXPHOS), the cellular bioenergetic systems. Since there are thousands of bioenergetic genes dispersed across the chromosomes and mitochondrial DNA (mtDNA), both cis and trans regulation of the nDNA genes is required. The bioenergetic systems convert environmental calories into ATP, acetyl-Coenzyme A (acetyl-CoA), S-adenosyl-methionine (SAM), and reduced NAD+. When calories are abundant, ATP and acetyl-CoA phosphorylate and acetylate chromatin, opening the nDNA for transcription and replication. When calories are limiting, chromatin phosphorylation and acetylation are lost and gene expression is suppressed. DNA methylaton via SAM can also be modulated by mitochondrial function. Phosphorylation and acetylation are also pivotal to regulating cellular signal transduction pathways. Therefore, bioenergetics provides the interface between the environment and the epigenome. Consistent with this conclusion, the clinical phenotypes of bioenergetic diseases are strikingly similar to those observed in epigenetic diseases (Angelman, Rett, Fragile X Syndromes, the laminopathies, cancer, etc.), and an increasing number of epigenetic diseases are being associated with mitochondrial dysfunction. This bioenergetic-epigenomic hypothesis has broad implications for the etiology, pathophysiology, and treatment of a wide range of common diseases. PMID:19796712

  2. "Energetics of Nanomaterials"

    SciTech Connect

    Professor Alexandra Navrotsky

    2005-01-31

    This project represents a three-year collaboration among Alexandra Navrotsky, Brian Woodfield, Juliana Bocrio-Goates and Frances Hellman. It's purpose has been to explore the differences between bulk materials, nanoparticles, and thin films in terms of their thermodynamic properties, with an emphasis on heat capacities and entropies, as well as enthalpies. The three groups have brought very different expertise and capabilities to the project. Navrotsky is a solid-state chemist and geochemist, with a unique Thermochemistry Facility emphasizing enthalpy of formation measurements by high temperature oxide melt and room temperature acid solution calorimetry. Bocrio-Goates and Woodfield are physical chemists with unique capabilities in accurate cryogenic heat capacity measurements using adiabatic calorimetry. Hellman is a physicist with expertise in magnetism and heat capacity measurements using microscale ''detector on a chip'' calorimetric technology that she pioneered. The overarching question of the work is ''How does the free energy play out in nanoparticles''? or ''How do differences in free energy affect overall nanoparticle behavior''? Because the free energy represents the temperature-dependent balance between the enthalpy of a system and its entropy, there are two separate, but related, components to the experimental investigations: Solution calorimetric measurements provide the energetics and two types of heat capacity measurements the entropy. They use materials that are well characterized in other ways (structurally, magnetically, and chemically), and samples are shared across the collaboration.

  3. Iridium-Catalyzed Diastereoselective and Enantioselective Allylic Substitutions with Acyclic α-Alkoxy Ketones.

    PubMed

    Jiang, Xingyu; Chen, Wenyong; Hartwig, John F

    2016-05-01

    The asymmetric alkylation of acyclic ketones is a longstanding challenge in organic synthesis. Reported herein are diastereoselective and enantioselective allylic substitutions with acyclic α-alkoxy ketones catalyzed by a metallacyclic iridium complex to form products with contiguous stereogenic centers derived from the nucleophile and electrophile. These reactions occur between allyl methyl carbonates and unstabilized copper(I) enolates generated in situ from acyclic α-alkoxy ketones. The resulting products can be readily converted into enantioenriched tertiary alcohols and tetrahydrofuran derivatives without erosion of enantiomeric purity. PMID:27038004

  4. Identifying a Highly Active Copper Catalyst for KA(2) Reaction of Aromatic Ketones.

    PubMed

    Cai, Yujuan; Tang, Xinjun; Ma, Shengming

    2016-02-12

    The well-established A(3) coupling reaction of terminal alkynes, aldehydes, and amines provides the most straightforward approach to propargylic amines. However, the related reaction of ketones, especially aromatic ketones, is still a significant challenge. A highly efficient catalytic protocol has been developed for the coupling of aromatic ketones with amines and terminal alkynes, in which Cu(I) , generated in situ from the reduction of CuBr2 with sodium ascorbate, has been identified as the highly efficient catalyst. Since propargylic amines are versatile synthetic intermediates and important units in pharmaceutical products, such an advance will greatly stimulate research interest involving the previously unavailable propargylic amines. PMID:26660459

  5. Decreasing the Rate of Metabolic Ketone Reduction in the Discovery of a Clinical Acetyl-CoA Carboxylase Inhibitor for the Treatment of Diabetes

    PubMed Central

    2015-01-01

    Acetyl-CoA carboxylase (ACC) inhibitors offer significant potential for the treatment of type 2 diabetes mellitus (T2DM), hepatic steatosis, and cancer. However, the identification of tool compounds suitable to test the hypothesis in human trials has been challenging. An advanced series of spirocyclic ketone-containing ACC inhibitors recently reported by Pfizer were metabolized in vivo by ketone reduction, which complicated human pharmacology projections. We disclose that this metabolic reduction can be greatly attenuated through introduction of steric hindrance adjacent to the ketone carbonyl. Incorporation of weakly basic functionality improved solubility and led to the identification of 9 as a clinical candidate for the treatment of T2DM. Phase I clinical studies demonstrated dose-proportional increases in exposure, single-dose inhibition of de novo lipogenesis (DNL), and changes in indirect calorimetry consistent with increased whole-body fatty acid oxidation. This demonstration of target engagement validates the use of compound 9 to evaluate the role of DNL in human disease. PMID:25423286

  6. Decreasing the rate of metabolic ketone reduction in the discovery of a clinical acetyl-CoA carboxylase inhibitor for the treatment of diabetes.

    PubMed

    Griffith, David A; Kung, Daniel W; Esler, William P; Amor, Paul A; Bagley, Scott W; Beysen, Carine; Carvajal-Gonzalez, Santos; Doran, Shawn D; Limberakis, Chris; Mathiowetz, Alan M; McPherson, Kirk; Price, David A; Ravussin, Eric; Sonnenberg, Gabriele E; Southers, James A; Sweet, Laurel J; Turner, Scott M; Vajdos, Felix F

    2014-12-26

    Acetyl-CoA carboxylase (ACC) inhibitors offer significant potential for the treatment of type 2 diabetes mellitus (T2DM), hepatic steatosis, and cancer. However, the identification of tool compounds suitable to test the hypothesis in human trials has been challenging. An advanced series of spirocyclic ketone-containing ACC inhibitors recently reported by Pfizer were metabolized in vivo by ketone reduction, which complicated human pharmacology projections. We disclose that this metabolic reduction can be greatly attenuated through introduction of steric hindrance adjacent to the ketone carbonyl. Incorporation of weakly basic functionality improved solubility and led to the identification of 9 as a clinical candidate for the treatment of T2DM. Phase I clinical studies demonstrated dose-proportional increases in exposure, single-dose inhibition of de novo lipogenesis (DNL), and changes in indirect calorimetry consistent with increased whole-body fatty acid oxidation. This demonstration of target engagement validates the use of compound 9 to evaluate the role of DNL in human disease. PMID:25423286

  7. Decreasing the Rate of Metabolic Ketone Reduction in the Discovery of a Clinical Acetyl-CoA Carboxylase Inhibitor for the Treatment of Diabetes

    SciTech Connect

    Griffith, David A.; Kung, Daniel W.; Esler, William P.; Amor, Paul A.; Bagley, Scott W.; Beysen, Carine; Carvajal-Gonzalez, Santos; Doran, Shawn D.; Limberakis, Chris; Mathiowetz, Alan M.; McPherson, Kirk; Price, David A.; Ravussin, Eric; Sonnenberg, Gabriele E.; Southers, James A.; Sweet, Laurel J.; Turner, Scott M.; Vajdos, Felix F.

    2014-12-26

    We found that Acetyl-CoA carboxylase (ACC) inhibitors offer significant potential for the treatment of type 2 diabetes mellitus (T2DM), hepatic steatosis, and cancer. However, the identification of tool compounds suitable to test the hypothesis in human trials has been challenging. An advanced series of spirocyclic ketone-containing ACC inhibitors recently reported by Pfizer were metabolized in vivo by ketone reduction, which complicated human pharmacology projections. Here, we disclose that this metabolic reduction can be greatly attenuated through introduction of steric hindrance adjacent to the ketone carbonyl. Incorporation of weakly basic functionality improved solubility and led to the identification of 9 as a clinical candidate for the treatment of T2DM. Phase I clinical studies demonstrated dose-proportional increases in exposure, single-dose inhibition of de novo lipogenesis (DNL), and changes in indirect calorimetry consistent with increased whole-body fatty acid oxidation. This demonstration of target engagement validates the use of compound 9 to evaluate the role of DNL in human disease.

  8. In vitro evaluation of bioactivity of chemically deposited hydroxyapatite on polyether ether ketone.

    PubMed

    Almasi, D; Izman, S; Sadeghi, M; Iqbal, N; Roozbahani, F; Krishnamurithy, G; Kamarul, T; Abdul Kadir, M R

    2015-01-01

    Polyether ether ketone (PEEK) is considered the best alternative material for titanium for spinal fusion cage implants due to its low elasticity modulus and radiolucent property. The main problem of PEEK is its bioinert properties. Coating with hydroxyapatite (HA) showed very good improvement in bioactivity of the PEEK implants. However the existing methods for deposition of HA have some disadvantages and damage the PEEK substrate. In our previous study a new method for deposition of HA on PEEK was presented. In this study cell proliferation of mesenchymal stem cell and apatite formation in simulated body fluid (SBF) tests were conducted to probe the effect of this new method in improvement of the bioactivity of PEEK. The mesenchymal stem cell proliferation result showed better cells proliferation on the treated layer in comparison with untreated PEEK. The apatite formation results showed the growth of the HA on the treated PEEK but there was not any sight of the growth of HA on the untreated PEEK even after 2 weeks. The results showed the new method of the HA deposition improved the bioactivity of the treated PEEK in comparison with the bare PEEK. PMID:25838826

  9. Solar Eruptions and Energetic Particles

    NASA Astrophysics Data System (ADS)

    Gopalswamy, Natchimuthukonar; Mewaldt, Richard; Torsti, Jarmo

    Coronal mass ejections (CMEs) are the most energetic events in the heliosphere. During solar cycle 23, the close connection between CMEs and solar energetic particles (SEPs) was studied in much greater detail than was previously possible, including effects on space weather. This book reviews extensive observations of solar eruptions and SEPs from orbiting and ground-based systems. From SOHO and ACE to RHESSI and TRACE, we now have measurements of unprecedented sensitivity by which to test assumptions and refine models. Discussion and analysis of: • Coronal mass ejections and energetic particles over one solar cycle • Implications of solar eruptions for space weather and human space exploration • The elemental, isotopic, and ionic charge state composition of accelerated particles • Complex interconnections among CMEs, flares, shocks, and energetic particles will make this book an indispensable resource for scientists working on the Sun-Earth connection, including space physicists, magnetospheric physicists, atmospheric physicists, astrophysicists, and aeronomists.

  10. Voyager 2 Observes Energetic Electrons

    NASA Video Gallery

    This animation shows the Voyager 2 observations of energetic electrons. Voyager 2 detected a dramatic drop of the flux of electrons as it left the sector region. The intense flux came back as soon ...

  11. Photodecomposition of energetic nitro compounds

    SciTech Connect

    Mialocq, J.C.

    1989-03-14

    The photodecomposition of energetic nitrocompounds depends on the excitation energy, the light intensity which determines the mono-, bi- or multiphotonic character of the initial process and their gaseous, liquid or solid state. The initial processes of the photodecomposition of nitromethane and nitroalcanes are reviewed and their relevance to the initiation of energetic nitrocompounds detonation is discussed. The case of nitramines (dimethylnitramine and tutorial) is also briefly introduced.

  12. Iron Mineral Effects on Ketone Reactions in Hydrothermal Fluids

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Gould, I. R.; Shock, E.

    2011-12-01

    Interactions in hydrothermal environments suggest that minerals participate in and alter organic compounds transformations at high temperatures and pressures [1]. Our previous experimental studies of a model ketone (dibenzyl ketone, DBK) in aqueous media under hydrothermal conditions (700 bars, 300 °C) indicate low conversion but multiple reaction pathways yielding diverse products. In the absence of minerals, DBK not only reversibly interconverts into 1,3-diphenyl-2-propanol, 1,3-diphenylpropene and 1,3-diphenylpropane along a reduction pathway, but also yields products including toluene, bibenzyl, stilbene and conjugated, dehydrogenated three- and four-ring coupling products from carbon-carbon (C-C) and carbon-hydrogen (C-H) bond-breaking pathways. Experiments involving oxide minerals that are not sensitive to redox process, such as quartz and corundum, show no effect when compared with H2O alone in changing DBK hydrothermal reactions and product distributions. In the presence of iron bearing minerals, however, we observe that the overall reaction conversion of DBK increases by orders of magnitude, and that reaction pathways are controlled or favored differently if hematite (Fe2O3), magnetite (Fe3O4) or ferrous sulfide (FeS) is present. As an example, with the same mineral surface area, Fe2O3 expedites DBK conversion from 6.4% (H2O only) to 26.4% after 168 hours, while Fe3O4 increases conversion up to 46.8%. Although more products are formed with introduction of iron oxide minerals, the major products are identical to those found in H2O alone, such as toluene, bibenzyl and a few large coupling products from the bond-breaking pathways. Hydrothermal experiments using a synthesized asymmetrical p-methyl-DBK under the same conditions conducted with Fe2O3 and Fe3O4 are consistent with those for DBK, showing higher conversion than in H2O, and more bond-breaking products like toluene, p-xylene, and three kinds of bibenzyls. This suggests that both Fe2O3 and Fe3O4

  13. Solar Energetic Particle Variations

    NASA Technical Reports Server (NTRS)

    Reames, D. V.

    2003-01-01

    In the largest solar energetic-particle (SEP) events, acceleration occurs at shock waves driven out from the Sun by coronal mass ejections (CMEs). In fact, the highest proton intensities directly measured near Earth at energies up to approximately 1 GeV occur at the time of passage of shocks, which arrive about a day after the CMEs leave the Sun. CME-driven shocks expanding across magnetic fields can fill over half of the heliosphere with SEPs. Proton-generated Alfven waves trap particles near the shock for efficient acceleration but also throttle the intensities at Earth to the streaming limit early in the events. At high energies, particles begin to leak from the shock and the spectrum rolls downward to form an energy-spectral 'knee' that can vary in energy from approximately 1 MeV to approximately 1 GeV in different events. All of these factors affect the radiation dose as a function of depth and latitude in the Earth's atmosphere and the risk to astronauts and equipment in space. SEP ionization of the polar atmosphere produces nitrates that precipitate to become trapped in the polar ice. Observations of nitrate deposits in ice cores reveal individual large SEP events and extend back approximately 400 years. Unlike sunspots, SEP events follow the approximately 80-100-year Gleissberg cycle rather faithfully and are now at a minimum in that cycle. The largest SEP event in the last 400 years appears to be related to the flare observed by Carrington in 1859, but the probability of SEP events with such large fluences falls off sharply because of the streaming limit.

  14. Research on new energetic materials

    SciTech Connect

    Miller, R.S.

    1996-07-01

    Fluorine and oxygen rich energetic crystals and polymers will provide a new approach to increasing composite propellant and explosive energy density and energy release rates. This class of energetic materials will be used to demonstrate that advances in computational chemistry and solid state physics can be used to begin to understand detonation and combustion processes. It is anticipated that fluorinated as well as the oxygenated combustion and detonation products will accelerate the rates of metal particle consumption in composite propellants and explosives. Enhanced and tailorable energy release rates and critical diameters of metallized composite explosives will provide new technological opportunities for both military and civilian applications. Environmentally friendly energetic materials are of great current interest to reduce life cycle waste and pollution as well as life cycle cost. Thermoplastic elastomers, which have reversible crosslinking mechanisms, are one of the required keys to the gate and pathway to achieving substantial waste and pollution reduction goals. The goal in this paper is to review progress in two emerging topics in energetic materials science. These emerging two areas are fluorine and oxygen rich energetic crystals and polymers and environmentally friendly energetic material classes. 33 refs., 12 figs.

  15. Solvent-induced crystallization of poly(ether ether ketone)

    NASA Astrophysics Data System (ADS)

    McPeak, Jennifer Lynne

    The purpose of this study was learn how the diffusion, swelling, and crystallization processes are coupled during solvent-induced crystallization of poly(ether ether ketone) (PEEK). Unoriented amorphous PEEK films were immersed in aprotic organic liquids at ambient temperature and bulk properties or characteristics were monitored as a function of immersion time. The sorption behavior, T g and Tm° suppression, crystallinity, and dynamic mechanical response were correlated as a function of solvent chemistry and immersion time. The saturation time of methylene chloride, 1,3-dichloropropane, tetrahydrofuran, cyclopentanone, chlorobenzene, toluene, diethyl ketone, and ethylbenzene in amorphous PEEK films were found to range from hours to days depending on the level of polymer-solvent interactions. In-situ isochronal DMA spectra show that the Tg of PEEK was suppressed from 150°C to below ambient temperature such that crystallization was kinetically feasible during ambient immersion. In addition, an increase in viscoelastic dispersion was attributed to the presence of crystallinity. From dynamic mass uptake and wide-angle x-ray diffraction (WAXD) results, it was found that the bulk sorption rate was equal to the bulk crystallization rate for all solvent systems that promoted SINC and PEEK exhibited diffusion-limited crystallization, irrespective of the nature of the transport mechanism. In addition, the solvent-induced crystals exhibit preferred orientation as supported by photographic WAXD. A distinct sorption front, observed with scanning electron microscopy, further supports the scenario of diffusion-controlled crystallization and one-dimensional diffusion. Isothermal DMA spectra for THF, cyclopentanone, and chlorobenzene, indicate that, as the solvent diffuses into the films, the stiffness of the polymer decreases at short times, begins to increase, and then reaches a relatively time-independent value. It was determined that the initial decrease in the storage

  16. Synthesis of Acridines by the [4 + 2] Annulation of Arynes and 2-Aminoaryl Ketones

    PubMed Central

    Rogness, Donald C.; Larock, Richard C.

    2010-01-01

    The reaction of 2-aminoaryl ketones and arynes generated by the treatment of various o-(trimethylsilyl)aryl triflates with CsF results in [4 + 2] annulation to afford substituted acridines in good yields. PMID:20222700

  17. Constituents of Artemisia gmelinii Weber ex Stechm. from Uttarakhand Himalaya: A Source of Artemisia Ketone.

    PubMed

    Haider, S Z; Andola, H C; Mohan, M

    2012-05-01

    The essential oils isolated from the aerial parts of two different populations of Artemisia gmelinii growing in Uttarakhand Himalaya region were analysed by gas chromatography and gas chromatography/mass spectrometry (GC-MS) in order to determine the variation of concentration in their constituents. Artemisia ketone was detected as a major constituent in both the populations i.e., Niti valley and Jhelum samples. Niti oil was found to have considerably greater amounts of artemesia ketone (53.34%) followed by α-thujone (9.91%) and 1,8-cineole (6.57%), Similarly, the first major compound in Jhelum oil was artemesia ketone (40.87%), whereas ar-curcumene (8.54%) was identified as a second major compound followed by α-thujone (4.04%). Artemisia ketone can be useful for perfumery and fragrance to introduce new and interesting herbaceous notes. PMID:23439844

  18. Transition metal-catalyzed ketone-directed or mediated C-H functionalization.

    PubMed

    Huang, Zhongxing; Lim, Hee Nam; Mo, Fanyang; Young, Michael C; Dong, Guangbin

    2015-11-01

    Transition metal-catalyzed C-H functionalization has evolved into a prominent and indispensable tool in organic synthesis. While nitrogen, phosphorus and sulfur-based functional groups (FGs) are widely employed as effective directing groups (DGs) to control the site-selectivity of C-H activation, the use of common FGs (e.g. ketone, alcohol and amine) as DGs has been continuously pursued. Ketones are an especially attractive choice of DGs and substrates due to their prevalence in various molecules and versatile reactivity as synthetic intermediates. Over the last two decades, transition metal-catalyzed C-H functionalization that is directed or mediated by ketones has experienced vigorous growth. This review summarizes these advancements into three major categories: use of ketone carbonyls as DGs, direct β-functionalization, and α-alkylation/alkenylation with unactivated olefins and alkynes. Each of these subsections is discussed from the perspective of strategic design and reaction discovery. PMID:26185960

  19. Efficient Domino Hydroformylation/Benzoin Condensation: Highly Selective Synthesis of α-Hydroxy Ketones.

    PubMed

    Dong, Kaiwu; Sang, Rui; Soule, Jean-Francois; Bruneau, Christian; Franke, Robert; Jackstell, Ralf; Beller, Matthias

    2015-12-01

    An improved domino hydroformylation/benzoin condensation to give α-hydroxy ketones has been developed. Easily available olefins are smoothly converted into the corresponding α-hydroxy ketones in high yields with excellent regioselectivities. Key to success is the use of a specific catalytic system consisting of a rhodium/phosphine complex and the CO2 adduct of an N-heterocyclic carbene. PMID:26503672

  20. Photoredox Activation for the Direct β-Arylation of Ketones and Aldehydes

    PubMed Central

    Pirnot, Michael T.; Rankic, Danica A.; Martin, David B. C.; MacMillan, David W. C.

    2013-01-01

    The direct β-activation of saturated aldehydes and ketones has long been an elusive transformation. We found that photoredox catalysis in combination with organocatalysis can lead to the transient generation of 5π-electron β-enaminyl radicals from ketones and aldehydes that rapidly couple with cyano-substituted aryl rings at the carbonyl β-position. This mode of activation is suitable for a broad range of carbonyl β-functionalization reactions and is amenable to enantioselective catalysis. PMID:23539600

  1. Synthesis of cyclic enones via direct palladium-catalyzed aerobic dehydrogenation of ketones.

    PubMed

    Diao, Tianning; Stahl, Shannon S

    2011-09-21

    α,β-Unsaturated carbonyl compounds are versatile intermediates in the synthesis of pharmaceuticals and biologically active compounds. Here, we report the discovery and application of Pd(DMSO)(2)(TFA)(2) as a catalyst for direct dehydrogenation of cyclohexanones and other cyclic ketones to the corresponding enones, using O(2) as the oxidant. The substrate scope includes heterocyclic ketones and several natural-product precursors. PMID:21851123

  2. Synthesis of Cyclic Enones via Direct Palladium-Catalyzed Aerobic Dehydrogenation of Ketones

    PubMed Central

    Diao, Tianning

    2011-01-01

    α,β-Unsaturated carbonyl compounds are versatile intermediates in the synthesis of pharmaceuticals and biologically active compounds. Here, we report the discovery and application of Pd(DMSO)2(TFA)2 as a catalyst for direct dehydrogenation of cyclohexanones and other cyclic ketones to the corresponding enones, using O2 as the oxidant. The substrate scope includes heterocyclic ketones and several natural-product precursors. PMID:21851123

  3. Studies of the condensation of sulfones with ketones and aldehydes.

    PubMed

    Garst, Michael E; Dolby, Lloyd J; Esfandiari, Shervin; Okrent, Rachel A; Avey, Alfred A

    2006-01-20

    [reaction: see text] The condensation of ketones or aldehydes with sulfones was shown to give a variety of products. Condensation of 2-methylcyclohexanone with dimethyl sulfone using potassium t-butoxide as base gave useful yields of 1,2-dimethylenecyclohexane. Under the same conditions, cycloheptanone, 3-methyl-2-butanone, and 2-butanone were converted to dienes. Remarkably, these reaction conditions converted acetophenone into p-terphenyl (10%) and (E)-1,4-diphenyl-3-penten-1-one (44%). Propiophenone was converted to 2'-methyl-p-terphenyl (61%). Using alpha-tetralone produced 1-methynaphthalene and naphthalene. No reaction took place with beta-tetralone. Using diethyl sulfone with alpha-tetralone lead to pure naphthalene. Condensation of isobutyraldehyde and dimethyl sulfone using potassium t-butoxide gave isoprene in low yield. Using benzaldehyde and benzyl phenyl sulfone in N,N-dimethylacetamide gave 1,2-diphenyl-1-phenylsulfonylethylene, N,N-dimethylcinnamide, and a complex condensation product. Only 1,2-diphenyl-1-phenylsulfonylethylene was obtained when the solvent was THF. PMID:16408963

  4. Flow-Induced Crystallization of Poly(ether ether ketone)

    NASA Astrophysics Data System (ADS)

    Nazari, Behzad; Rhoades, Alicyn; Colby, Ralph

    The effects of an interval of shear above the melting temperature Tm on subsequent isothermal crystallization below Tm is reported for the premier engineering thermoplastic, poly(ether ether ketone) (PEEK). The effect of shear on the crystallization rate of PEEK is investigated by means of rheological techniques and differential scanning calorimetry (DSC) under a protocol of imposing shear in a rotational cone and plate rheometer and monitoring crystallization after quenching. The rate of crystallization at 320 °C was not affected by shear for shear rates <7 s-1 at 350 °C, whereas intervals of adequate shear at higher shear rates prior to the quench to 320 °C accelerated crystallization significantly. As the duration of the interval of shear above 7 s-1 is increased, the crystallization time decreases but at each shear rate eventually saturates once the applied specific work exceeds ~120 MPa. The annealing of the flow-induced precursors was also investigated. The nuclei were fairly persistent at temperatures close to 350 °C, however very unstable at temperatures above 375 °C. This suggests that the nanostructures formed under shear might be akin to crystalline lamellae of greater thickness, compared to quiescently crystallized lamellae.

  5. Catalytic, Enantioselective Sulfenylation of Ketone-Derived Enoxysilanes

    PubMed Central

    2015-01-01

    A catalytic, enantioselective, Lewis base-catalyzed α-sulfenylation of silyl enol ethers has been developed. To avoid acidic hydrolysis of the silyl enol ether substrates, a sulfenylating agent that did not require additional Brønsted acid activation, namely N-phenylthiosaccharin, was developed. Three classes of Lewis bases—tertiary amines, sulfides, and selenophosphoramides—were identified as active catalysts for the α-sulfenylation reaction. Among a wide variety of chiral Lewis bases in all three classes, only chiral selenophosphoramides afforded α-phenylthio ketones in generally high yield and with good enantioselectivity. The selectivity of the reaction does not depend on the size of the silyl group but is highly sensitive to the double bond geometry and the bulk of the substituents on the double bond. The most selective substrates are those containing a geminal bulky substituent on the enoxysilane. Computational analysis revealed that the enantioselectivity arises from an intriguing interplay among sterically guided approach, distortion energy, and orbital interactions. PMID:25192220

  6. Metabolism of alkenes and ketones by Candida maltosa and related yeasts

    PubMed Central

    2014-01-01

    Knowledge is scarce about the degradation of ketones in yeasts. For bacteria a subterminal degradation of alkanes to ketones and their further metabolization has been described which always involved Baeyer-Villiger monooxygenases (BVMOs). In addition, the question has to be clarified whether alkenes are converted to ketones, in particular for the oil degrading yeast Candida maltosa little is known. In this study we show the degradation of the aliphatic ketone dodecane-2-one by Candida maltosa and the related yeasts Candida tropicalis, Candida catenulata and Candida albicans as well as Trichosporon asahii and Yarrowia lipolytica. One pathway is initiated by the formation of decyl acetate, resulting from a Baeyer-Villiger-oxidation of this ketone. Beyond this, an initial reduction to dodecane-2-ol by a keto reductase was clearly shown. In addition, two different ways to metabolize dodec-1-ene were proposed. One involved the formation of dodecane-2-one and the other one a conversion leading to carboxylic and dicarboxylic acids. Furthermore the induction of ketone degrading enzymes by dodecane-2-one and dodec-1-ene was shown. Interestingly, with dodecane no subterminal degradation products were detected and it did not induce any enzymes to convert dodecane-2-one. PMID:25309846

  7. Studies on the interaction between ethanol and two industrial solvents (methyl isobutyl ketone) in mice

    SciTech Connect

    Granvil, C.P.; Sharkawi, M.; Plaa, G.L. )

    1991-03-11

    Methyl n-butyl ketone (MnBK) and methyl isobutyl ketone (MiBK) prolong the duration of ethanol-induced loss of righting reflex (EILRR) in mice. MnBK was almost twice as potent in this regard. To explain this difference, the metabolism of both ketones was studied in male CD-1 mice using GC. MiBK was converted to 4-methyl-2-pentanol (4MPOL) and 4-hydroxy methyl isobutyl ketone (HMP). MnBK metabolites were 2-hexanol (2HOL) and 2,5-hexanedione (2,5HD). The effects of both ketones and metabolites on EILRR and ethanol (E) elimination were studied in mice. The ketones and their metabolites were dissolved in corn oil and injected intraperitoneally 30 min before E 4g/kg for EILRR and 2g/kg for E elimination. In the following doses: MnBK, 5; MiBK, 5; 2HOL, 2.5; 4MPOL, 2.5; and HMP 2.5, significantly prolonged EILRR. Concentrations of E in blood and brain upon return of the righting reflex were similar in solvent-treated and control animals. The mean elimination rate of E was slower in groups given MnBK or 2HOL than in control animals. No change in E elimination was observed with MiBK, HMP, 4MPOL, or 2, 5HD.

  8. Solar flares and energetic particles.

    PubMed

    Vilmer, Nicole

    2012-07-13

    Solar flares are now observed at all wavelengths from γ-rays to decametre radio waves. They are commonly associated with efficient production of energetic particles at all energies. These particles play a major role in the active Sun because they contain a large amount of the energy released during flares. Energetic electrons and ions interact with the solar atmosphere and produce high-energy X-rays and γ-rays. Energetic particles can also escape to the corona and interplanetary medium, produce radio emissions (electrons) and may eventually reach the Earth's orbit. I shall review here the available information on energetic particles provided by X-ray/γ-ray observations, with particular emphasis on the results obtained recently by the mission Reuven Ramaty High-Energy Solar Spectroscopic Imager. I shall also illustrate how radio observations contribute to our understanding of the electron acceleration sites and to our knowledge on the origin and propagation of energetic particles in the interplanetary medium. I shall finally briefly review some recent progress in the theories of particle acceleration in solar flares and comment on the still challenging issue of connecting particle acceleration processes to the topology of the complex magnetic structures present in the corona. PMID:22665901

  9. The energetic basis of acoustic communication

    PubMed Central

    Gillooly, James F.; Ophir, Alexander G.

    2010-01-01

    Animals produce a tremendous diversity of sounds for communication to perform life's basic functions, from courtship and parental care to defence and foraging. Explaining this diversity in sound production is important for understanding the ecology, evolution and behaviour of species. Here, we present a theory of acoustic communication that shows that much of the heterogeneity in animal vocal signals can be explained based on the energetic constraints of sound production. The models presented here yield quantitative predictions on key features of acoustic signals, including the frequency, power and duration of signals. Predictions are supported with data from nearly 500 diverse species (e.g. insects, fishes, reptiles, amphibians, birds and mammals). These results indicate that, for all species, acoustic communication is primarily controlled by individual metabolism such that call features vary predictably with body size and temperature. These results also provide insights regarding the common energetic and neuromuscular constraints on sound production, and the ecological and evolutionary consequences of producing these sounds. PMID:20053641

  10. The energetic basis of acoustic communication.

    PubMed

    Gillooly, James F; Ophir, Alexander G

    2010-05-01

    Animals produce a tremendous diversity of sounds for communication to perform life's basic functions, from courtship and parental care to defence and foraging. Explaining this diversity in sound production is important for understanding the ecology, evolution and behaviour of species. Here, we present a theory of acoustic communication that shows that much of the heterogeneity in animal vocal signals can be explained based on the energetic constraints of sound production. The models presented here yield quantitative predictions on key features of acoustic signals, including the frequency, power and duration of signals. Predictions are supported with data from nearly 500 diverse species (e.g. insects, fishes, reptiles, amphibians, birds and mammals). These results indicate that, for all species, acoustic communication is primarily controlled by individual metabolism such that call features vary predictably with body size and temperature. These results also provide insights regarding the common energetic and neuromuscular constraints on sound production, and the ecological and evolutionary consequences of producing these sounds. PMID:20053641

  11. Zeolite synthesis: an energetic perspective.

    PubMed

    Zwijnenburg, Martijn A; Bromley, Stefan T

    2010-11-21

    Taking |D(H(2)O)(x)|[AlSiO(4)] based materials (where D is Li, Na, K, Rb or Cs) as an archetypal aluminosilicate system, we use accurate density functional theory calculations to demonstrate how the substitution of silicon cations in silica, with pairs of aluminium and (alkali metal) cations, changes the energetic ordering of different competing structure-types. For large alkali metal cations we further show that the formation of porous aluminosilicate structures, the so-called zeolites, is energetically favored. These findings unequivocally demonstrate that zeolites can be energetic preferred reaction products, rather than being kinetically determined, and that the size of the (hydrated) cations in the pore, be it inorganic or organic, is critical for directing zeolite synthesis. PMID:20938518

  12. Energetics of life on the deep seafloor

    PubMed Central

    McClain, Craig R.; Allen, Andrew P.; Tittensor, Derek P.; Rex, Michael A.

    2012-01-01

    With frigid temperatures and virtually no in situ productivity, the deep oceans, Earth’s largest ecosystem, are especially energy-deprived systems. Our knowledge of the effects of this energy limitation on all levels of biological organization is very incomplete. Here, we use the Metabolic Theory of Ecology to examine the relative roles of carbon flux and temperature in influencing metabolic rate, growth rate, lifespan, body size, abundance, biomass, and biodiversity for life on the deep seafloor. We show that the relative impacts of thermal and chemical energy change across organizational scales. Results suggest that individual metabolic rates, growth, and turnover proceed as quickly as temperature-influenced biochemical kinetics allow but that chemical energy limits higher-order community structure and function. Understanding deep-sea energetics is a pressing problem because of accelerating climate change and the general lack of environmental regulatory policy for the deep oceans. PMID:22949638

  13. The Stereoselective Reductions of Ketones to the Most Thermodynamically Stable Alcohols Using Lithium and Hydrated Salts of Common Transition Metals.

    PubMed

    Kennedy, Nicole; Cohen, Theodore

    2015-08-21

    A simple method is presented for the highly stereoselective reductions of ketones to the most thermodynamically stable alcohols. In this procedure, the ketone is treated with lithium dispersion and either FeCl2·4H2O or CuCl2·2H2O in THF at room temperature. This protocol is applied to a large number and variety of ketones and is both more convenient and efficient than those commonly reported for the diastereoselective reduction of five- and six-membered cyclic ketones. PMID:26226182

  14. Mitochondrial biogenesis and increased uncoupling protein 1 in brown adipose tissue of mice fed a ketone ester diet

    PubMed Central

    Srivastava, Shireesh; Kashiwaya, Yoshihiro; King, M. Todd; Baxa, Ulrich; Tam, Joseph; Niu, Gang; Chen, Xiaoyuan; Clarke, Kieran; Veech, Richard L.

    2012-01-01

    We measured the effects of a diet in which d-β-hydroxybutyrate-(R)-1,3 butanediol monoester [ketone ester (KE)] replaced equicaloric amounts of carbohydrate on 8-wk-old male C57BL/6J mice. Diets contained equal amounts of fat, protein, and micronutrients. The KE group was fed ad libitum, whereas the control (Ctrl) mice were pair-fed to the KE group. Blood d-β-hydroxybutyrate levels in the KE group were 3-5 times those reported with high-fat ketogenic diets. Voluntary food intake was reduced dose dependently with the KE diet. Feeding the KE diet for up to 1 mo increased the number of mitochondria and doubled the electron transport chain proteins, uncoupling protein 1, and mitochondrial biogenesis-regulating proteins in the interscapular brown adipose tissue (IBAT). [18F]-Fluorodeoxyglucose uptake in IBAT of the KE group was twice that in IBAT of the Ctrl group. Plasma leptin levels of the KE group were more than 2-fold those of the Ctrl group and were associated with increased sympathetic nervous system activity to IBAT. The KE group exhibited 14% greater resting energy expenditure, but the total energy expenditure measured over a 24-h period or body weights was not different. The quantitative insulin-sensitivity check index was 73% higher in the KE group. These results identify KE as a potential antiobesity supplement.—Srivastava, S., Kashiwaya, Y., King, M. T. Baxa, U., Tam, J., Niu, G., Chen, X., Clarke, K., Veech, R. L. Mitochondrial biogenesis and increased uncoupling protein 1 in brown adipose tissue of mice fed a ketone ester diet. PMID:22362892

  15. Jet propagation through energetic materials

    SciTech Connect

    Pincosy, P; Poulsen, P

    2004-01-08

    In applications where jets propagate through energetic materials, they have been observed to become sufficiently perturbed to reduce their ability to effectively penetrate subsequent material. Analytical calculations of the jet Bernoulli flow provides an estimate of the onset and extent of such perturbations. Although two-dimensional calculations show the back-flow interaction pressure pulses, the symmetry dictates that the flow remains axial. In three dimensions the same pressure impulses can be asymmetrical if the jet is asymmetrical. The 3D calculations thus show parts of the jet having a significant component of radial velocity. On the average the downstream effects of this radial flow can be estimated and calculated by a 2D code by applying a symmetrical radial component to the jet at the appropriate position as the jet propagates through the energetic material. We have calculated the 3D propagation of a radio graphed TOW2 jet with measured variations in straightness and diameter. The resultant three-dimensional perturbations on the jet result in radial flow, which eventually tears apart the coherent jet flow. This calculated jet is compared with jet radiographs after passage through the energetic material for various material thickness and plate thicknesses. We noted that confinement due to a bounding metal plate on the energetic material extends the pressure duration and extent of the perturbation.

  16. The Giotto Energetic Particle Experiment.

    NASA Astrophysics Data System (ADS)

    McKenna-Lawlor, S.; Thompson, A.; O'Sullivan, D.; Kirsch, E.; Melrose, D.; Wenzel, K.-P.

    The Energetic Particle Experiment (EPA) onboard Giotto will measure the energy distribution of electrons, protons and heavier nuclei with E ≥ 20 keV during the cruise phase and in the cometary environment during Halley encounter. The detector system and the main scientific objectives of EPA are described.

  17. Electronic Interactions of Michler's Ketone with DNA Bases in Synthetic Hairpins.

    PubMed

    Jalilov, Almaz S; Young, Ryan M; Eaton, Samuel W; Wasielewski, Michael R; Lewis, Frederick D

    2015-01-01

    The mechanism and dynamics of photoinduced electron transfer in two families of DNA hairpins possessing Michler's ketone linkers have been investigated by means of steady state and time-resolved transient absorption and emission spectroscopies. The excited state behavior of the diol linker employed in hairpin synthesis is similar to that of Michler's ketone in methanol solution. Hairpins possessing only a Michler's ketone linker undergo fast singlet state charge separation and charge recombination with an adjacent purine base, attributed to well-stacked ground state conformations, and intersystem crossing to the triplet state, attributed to poorly stacked ground state conformations. The failure of the triplet to undergo electron transfer reactions on the 7 ns time scale of our measurements is attributed to the low triplet energy and reduction potential of the twisted triplet state. Hairpins possessing both a Michler's ketone linker and a perylenediimide base surrogate separated by four base pairs undergo photoinduced hole transport from the diimide to Michler's ketone upon excitation of the diimide. The efficiency of hole transport is dependent upon the sequence of the intervening purine bases. PMID:25296568

  18. Presence and potential significance of aromatic-ketone groups in aquatic humic substances

    USGS Publications Warehouse

    Leenheer, J.A.; Wilson, M.A.; Malcolm, R.L.

    1987-01-01

    Aquatic humic- and fulvic-acid standards of the International Humic Substances Society were characterized, with emphasis on carbonyl-group nature and content, by carbon-13 nuclear-magnetic-resonance spectroscopy, proton nuclear-magnetic-resonance spectroscopy, and infrared spectroscopy. After comparing spectral results of underivatized humic and fulvic acids with spectral results of chemically modified derivatives, that allow improved observation of the carbonyl group, the data clearly indicated that aromatic ketone groups comprised the majority of the carbonyl-group content. About one ketone group per monocyclic aromatic ring was determined for both humic and fulvic acids. Aromatic-ketone groups were hypothesized to form by photolytic rearrangements and oxidation of phenolic ester and hydrocarbon precursors; these groups have potential significance regarding haloform formation in water, reactivity resulting from active hydrogen of the methyl and methylene adjacent to the ketone groups, and formation of hemiketal and lactol structures. Aromatic-ketone groups also may be the point of attachment between aliphatic and aromatic moieties of aquatic humic-substance structure. ?? 1987.

  19. Low dielectric fluorinated poly(phenylene ether ketone) film and coating

    NASA Technical Reports Server (NTRS)

    Cassidy, Patrick E. (Inventor); Tullos, Gordon L. (Inventor); St.clair, Anne K. (Inventor)

    1990-01-01

    The present invention relates to film and coating materials prepared from novel fluorinated poly(phenylene ether ketones). A fluorinated poly(phenylene ether ketone) is prepared by reacting a bisphenol with 1,1,1,3,3,3 hexafluoro-2,2-bis 4-(4-halobenzoyl) phenyl propane (wherein halo is fluoro or chloro), which is a novel monomer formed as the reaction product of halobenzene (wherein halo is fluoro or chloro) and 1,1,1,3,3,3 hexafluoro-2,2-bis (p-chloro formyl phenyl) propane. Especially beneficial results of this invention are that films and coating materials prepared from the novel fluorinated poly(phenylene ether ketone) are essentially optically transparent/colorless and have a lower dielectric constant than otherwise comparable, commercially available poly(phenylene ether ketones). Moreover, unlike the otherwise comparable commercially available materials, the novel fluorinated poly(phenylene ether ketones) of the present invention can be solution cast or sprayed to produce the films and coatings. Furthermore, the long term thermal stability of the polymers of the present invention is superior to that of the commercially available materials.

  20. Bioconversion to Raspberry Ketone is Achieved by Several Non-related Plant Cell Cultures

    PubMed Central

    Häkkinen, Suvi T.; Seppänen-Laakso, Tuulikki; Oksman-Caldentey, Kirsi-Marja; Rischer, Heiko

    2015-01-01

    Bioconversion, i.e., the use of biological systems to perform chemical changes in synthetic or natural compounds in mild conditions, is an attractive tool for the production of novel active or high-value compounds. Plant cells exhibit a vast biochemical potential, being able to transform a range of substances, including pharmaceutical ingredients and industrial by-products, via enzymatic processes. The use of plant cell cultures offers possibilities for contained and optimized production processes which can be applied in industrial scale. Raspberry ketone [4-(4-hydroxyphenyl)butan-2-one] is among the most interesting natural flavor compounds, due to its high demand and significant market value. The biosynthesis of this industrially relevant flavor compound is relatively well characterized, involving the condensation of 4-coumaryl-CoA and malonyl-CoA by Type III polyketide synthase to form a diketide, and the subsequent reduction catalyzed by an NADPH-dependent reductase. Raspberry ketone has been successfully produced by bioconversion using different hosts and precursors to establish more efficient and economical processes. In this work, we studied the effect of overexpressed RiZS1 in tobacco on precursor bioconversion to raspberry ketone. In addition, various wild type plant cell cultures were studied for their capacity to carry out the bioconversion to raspberry ketone using either 4-hydroxybenzalacetone or betuligenol as a substrate. Apparently plant cells possess rather widely distributed reductase activity capable of performing the bioconversion to raspberry ketone using cheap and readily available precursors. PMID:26635853

  1. Photolysis study of fluorinated ketones under natural sunlight conditions.

    PubMed

    Díaz-de-Mera, Yolanda; Aranda, Alfonso; Notario, Alberto; Rodríguez, Ana; Rodríguez, Diana; Bravo, Iván

    2015-09-21

    UV-visible absorption cross-sections are reported for CF3C(O)CH3, CF3C(O)CH2CH3, and CH3CH2C(O)CH(CH3)2. The photolysis rate constants of CF3C(O)CH3, CF3C(O)CH2CH3, and CF3CF2C(O)CF(CF3)2 were measured from smog-chamber experiments carried out in a 400 L Teflon-bag reactor under sunlight irradiation. Actinic radiation profiles from the "Tropospheric Ultraviolet and Visible Radiation Model" were used to obtain quantum efficiencies of photolysis: 0.34 ± 0.08, 0.24 ± 0.06, and (4.4 ± 0.6) × 10(-2) for CF3C(O)CH3, CF3C(O)CH2CH3, and CF3CF2C(O)CF(CF3)2, respectively. These values correspond to wavelength ranges of 295-345 nm (for CF3C(O)CH3 and CF3C(O)CH2CH3) and 295-360 nm (for CF3CF2C(O)CF(CF3)2). The photolysis rate constants change significantly with the seasons, with the yearly averages being (2.3 ± 0.7) × 10(-6), (1.8 ± 0.6) × 10(-6), and (2.1 ± 0.8) × 10(-6) s(-1) for CF3C(O)CH3, CF3C(O)CH2CH3, and CF3CF2C(O)CF(CF3)2, respectively. Photolysis processes are fast and responsible for the short gas-phase lifetimes of the studied ketones, which are 5.1 ± 2.2, 6.5 ± 2.5 and 5.5 ± 1.5 days. The radiative forcing efficiencies are provided to assess the contribution of emissions of these gases to climate change. As a result of the short atmospheric lifetimes, their global warming potentials are negligible. Theoretical calculations involving ground and excited states justify the higher photolysis quantum efficiencies of CF3C(O)CH3 and CF3C(O)CH2CH3 compared to CF3CF2C(O)CF(CF3)2, which shows increased photolysis rate constants in the absence of O2. PMID:26270890

  2. Scaling the Thrust Production and Energetics of Inviscid Intermittent Swimming

    NASA Astrophysics Data System (ADS)

    Akoz, Emre; Moored, Keith

    2015-11-01

    Many fish have adopted an intermittent swimming gait sometimes referred as a burst-and-coast behavior. By using this gait, fish have been estimated at reducing their energetic cost of swimming by about 50%. Lighthill proposed that the skin friction drag of an undulating body can be around 400% greater than a rigidly-held coasting body, which may explain the energetic savings of intermittent swimming. Recent studies have confirmed the increase in skin friction drag over an undulating body, however, the increase is on the order of 20-70%. This more modest gain in skin friction drag is not sufficient to lead to the observed energy savings. Motivated by these observations, we investigate the inviscid mechanisms behind intermittent swimming for parameters typical of biology. We see that there is an energy savings at a fixed swimming speed for intermittent swimming as compared to continuous swimming. Then we consider three questions: What is the nature of the inviscid mechanism that leads to the observed energy savings, how do the forces and energetics of intermittent swimming scale with the swimming parameters, and what are the limitations to the benefit? Supported by the Office of Naval Research under Program Director Dr. Bob Brizzola, MURI grant number N00014-14-1-0533.

  3. The location of energetic compartments affects energetic communication in cardiomyocytes

    PubMed Central

    Birkedal, Rikke; Laasmaa, Martin; Vendelin, Marko

    2014-01-01

    The heart relies on accurate regulation of mitochondrial energy supply to match energy demand. The main regulators are Ca2+ and feedback of ADP and Pi. Regulation via feedback has intrigued for decades. First, the heart exhibits a remarkable metabolic stability. Second, diffusion of ADP and other molecules is restricted specifically in heart and red muscle, where a fast feedback is needed the most. To explain the regulation by feedback, compartmentalization must be taken into account. Experiments and theoretical approaches suggest that cardiomyocyte energetic compartmentalization is elaborate with barriers obstructing diffusion in the cytosol and at the level of the mitochondrial outer membrane (MOM). A recent study suggests the barriers are organized in a lattice with dimensions in agreement with those of intracellular structures. Here, we discuss the possible location of these barriers. The more plausible scenario includes a barrier at the level of MOM. Much research has focused on how the permeability of MOM itself is regulated, and the importance of the creatine kinase system to facilitate energetic communication. We hypothesize that at least part of the diffusion restriction at the MOM level is not by MOM itself, but due to the close physical association between the sarcoplasmic reticulum (SR) and mitochondria. This will explain why animals with a disabled creatine kinase system exhibit rather mild phenotype modifications. Mitochondria are hubs of energetics, but also ROS production and signaling. The close association between SR and mitochondria may form a diffusion barrier to ADP added outside a permeabilized cardiomyocyte. But in vivo, it is the structural basis for the mitochondrial-SR coupling that is crucial for the regulation of mitochondrial Ca2+-transients to regulate energetics, and for avoiding Ca2+-overload and irreversible opening of the mitochondrial permeability transition pore. PMID:25324784

  4. SIMULATION OF ENERGETIC NEUTRAL ATOMS FROM SOLAR ENERGETIC PARTICLES

    SciTech Connect

    Wang, Linghua; Li, Gang; Shih, Albert Y.; Lin, Robert P.; Wimmer-Schweingruber, Robert F.

    2014-10-01

    Energetic neutral atoms (ENAs) provide the only way to observe the acceleration site of coronal-mass-ejection-driven (CME-driven) shock-accelerated solar energetic particles (SEPs). In gradual SEP events, energetic protons can charge exchange with the ambient solar wind or interstellar neutrals to become ENAs. Assuming a CME-driven shock with a constant speed of 1800 km s{sup –1} and compression ratio of 3.5, propagating from 1.5 to 40 R{sub S} , we calculate the accelerated SEPs at 5-5000 keV and the resulting ENAs via various charge-exchange interactions. Taking into account the ENA losses in the interplanetary medium, we obtain the flux-time profiles of these solar ENAs reaching 1 AU. We find that the arriving ENAs at energies above ∼100 keV show a sharply peaked flux-time profile, mainly originating from the shock source below 5 R{sub S} , whereas the ENAs below ∼20 keV have a flat-top time profile, mostly originating from the source beyond 10 R{sub S} . Assuming the accelerated protons are effectively trapped downstream of the shock, we can reproduce the STEREO ENA fluence observations at ∼2-5 MeV/nucleon. We also estimate the flux of ENAs coming from the charge exchange of energetic storm protons, accelerated by the fast CME-driven shock near 1 AU, with interstellar hydrogen and helium. Our results suggest that appropriate instrumentation would be able to detect ENAs from SEPs and to even make ENA images of SEPs at energies above ∼10-20 keV.

  5. Highly Diastereoselective Chelation-controlled Additions to α-Silyloxy Ketones

    PubMed Central

    Stanton, Gretchen R.; Koz, Gamze

    2011-01-01

    The polar Felkin-Anh, Cornforth, and Cram-chelation models predict that the addition of organometallic reagents to silyl–protected α–hydroxy ketones proceeds via a non-chelation pathway to give anti-diol addition products. This prediction has held true for the vast majority of additions reported in the literature and few methods for chelation-controlled additions of organometallic reagents to silyl–protected α–hydroxy ketones have been introduced. Herein, we present a general and highly diastereoselective method for the addition of dialkylzincs and (E)-di-, (E)-tri- and (Z)-disubstituted vinylzinc reagents to α-silyloxy ketones using alkyl zinc halide Lewis acids, RZnX, to give chelation-controlled products (dr ≥18:1). The compatibility of organozinc reagents with other functional groups makes this method potentially very useful in complex molecule synthesis. PMID:21534530

  6. Diplogelasinospora grovesii IMI 171018 immobilized in polyurethane foam. An efficient biocatalyst for stereoselective reduction of ketones.

    PubMed

    Quezada, M A; Carballeira, J D; Sinisterra, J V

    2012-05-01

    Diplogelasinospora grovesii has been reported as a very active biocatalyst in the reduction of ketones. Along the text, the properties of this filamentous fungus as an immobilized catalyst are described. For this purpose, several immobilization supports as agar and polyurethane foam were tested. Experimental assays were also performed to test different co-substrates for the regeneration of the required enzyme cofactor. The fungus immobilized in polyurethane foam lead to the most stable and active catalyst. This derivative, using i-PrOH as co-substrate, could be reused at least 18 times without appreciable activity loss (>90% activity remains). Kinetic runs experiments shown that the reduction of cyclohexanone, selected as model substrate, followed a pseudo-first kinetic order and that the rate controlling step was the mass transfer through the cell wall. The deactivation kinetic constants were also determined. The reduction of different chiral ketones showed that the ketone reductase activity followed the Prelog's rule. PMID:22424921

  7. Carbon-Carbon Bond Formation and Hydrogen Production in the Ketonization of Aldehydes.

    PubMed

    Orozco, Lina M; Renz, Michael; Corma, Avelino

    2016-09-01

    Aldehydes possess relatively high chemical energy, which is the driving force for disproportionation reactions such as Cannizzaro and Tishchenko reactions. Generally, this energy is wasted if aldehydes are transformed into carboxylic acids with a sacrificial oxidant. Here, we describe a cascade reaction in which the surplus energy of the transformation is liberated as molecular hydrogen for the oxidation of heptanal to heptanoic acid by water, and the carboxylic acid is transformed into potentially industrially relevant symmetrical ketones by ketonic decarboxylation. The cascade reaction is catalyzed by monoclinic zirconium oxide (m-ZrO2 ). The reaction mechanism has been studied through cross-coupling experiments between different aldehydes and acids, and the final symmetrical ketones are formed by a reaction pathway that involves the previously formed carboxylic acids. Isotopic studies indicate that the carboxylic acid can be formed by a hydride shift from the adsorbed aldehyde on the metal oxide surface in the absence of noble metals. PMID:27539722

  8. C-Alkylation of Ketones and Related Compounds by Alcohols: Transition-Metal-Catalyzed Dehydrogenation.

    PubMed

    Huang, Fei; Liu, Zhuqing; Yu, Zhengkun

    2016-01-18

    Transition-metal-catalyzed C-alkylation of ketones and secondary alcohols, with alcohols, avoids use of organometallic or environmentally unfriendly alkylating agents by means of borrowing hydrogen (BH) or hydrogen autotransfer (HA) activation of the alcohol substrates. Water is formed as the only by-product, thus making the BH process atom-economical and environmentally benign. Diverse homogeneous and heterogeneous transition-metal catalysts, ketones, and alcohols can be used for this transformation, thus rendering the BH process promising for replacing those procedures that use traditional alkylating agents. This Minireview summarizes the advances during the last five years in transition-metal-catalyzed BH α-alkylation of ketones, and β-alkylation of secondary alcohols with alcohols. A discussion on the application of the BH strategy for C-C bond formation is included. PMID:26639633

  9. Enzymatic Chemoselective Aldehyde-Ketone Cross-Couplings through the Polarity Reversal of Methylacetoin.

    PubMed

    Bernacchia, Giovanni; Bortolini, Olga; De Bastiani, Morena; Lerin, Lindomar Alberto; Loschonsky, Sabrina; Massi, Alessandro; Müller, Michael; Giovannini, Pier Paolo

    2015-06-01

    The thiamine diphosphate (ThDP) dependent enzyme acetoin:dichlorophenolindophenol oxidoreductase (Ao:DCPIP OR) from Bacillus licheniformis was cloned and overexpressed in Escherichia coli. The recombinant enzyme shared close similarities with the acetylacetoin synthase (AAS) partially purified from Bacillus licheniformis suggesting that they could be the same enzyme. The product scope of the recombinant Ao:DCPIP OR was expanded to chiral tertiary α-hydroxy ketones through the rare aldehyde-ketone cross-carboligation reaction. Unprecedented is the use of methylacetoin as the acetyl anion donor in combination with a range of strongly to weakly activated ketones. In some cases, Ao:DCPIP OR produced the desired tertiary alcohols with stereochemistry opposite to that obtained with other ThDP-dependent enzymes. The combination of methylacetoin as acyl anion synthon and novel ThDP-dependent enzymes considerably expands the available range of C-C bond formations in asymmetric synthesis. PMID:25914187

  10. Asymmetric Catalysis with CO2 : The Direct α-Allylation of Ketones.

    PubMed

    Pupo, Gabriele; Properzi, Roberta; List, Benjamin

    2016-05-10

    Quaternary stereocenters are found in numerous bioactive molecules. The Tsuji-Trost reaction has proven to be a powerful C-C bond forming process, and, at least in principle, should be well suited to access quaternary stereocenters via the α-allylation of ketones. However, while indirect approaches are known, the direct, catalytic asymmetric α-allylation of branched ketones has been elusive until today. By combining "enol catalysis" with the use of CO2 as a formal catalyst for asymmetric catalysis, we have now developed a solution to this problem: we report a direct, highly enantioselective and highly atom-economic Tsuji-Trost allylation of branched ketones with allylic alcohol. Our reaction delivers products bearing quaternary stereocenters with high enantioselectivity and water as the sole by-product. We expect our methodology to be of utility in asymmetric catalysis and inspire the design of other highly atom-economic transformations. PMID:27071633