Nucleic Acid Aptamers Against Biotoxins: A New Paradigm Toward the Treatment and Diagnostic Approach

DEFF Research Database (Denmark)

Lauridsen, Lasse Holm; Veedu, Rakesh N.

2012-01-01

Nucleic acid aptamers are short single-stranded DNA or RNA oligonucleotides that can bind to their targets with very high affinity and specificity, and are generally selected by a process referred to as systematic evolution of ligands by exponential enrichment. Conventional antibody-based therape......Nucleic acid aptamers are short single-stranded DNA or RNA oligonucleotides that can bind to their targets with very high affinity and specificity, and are generally selected by a process referred to as systematic evolution of ligands by exponential enrichment. Conventional antibody......-based therapeutic and diagnostic approach currently employed against biotoxins pose major limitations such as the requirement of a live animal for the in vivo enrichment of the antibody species, decreased stability, high production cost, and side effects. Aptamer technology is a viable alternative that can be used...

Current management of oral cancer. A multidisciplinary approach.

Science.gov (United States)

Ord, R A; Blanchaert, R H

2001-11-01

Recent basic science discoveries have contributed to our understanding of the etiology of oral cancer and allowed us to consider innovative approaches to therapy. The authors evaluated and summarized current approaches to the management of oral cancer, emphasizing the multidisciplinary team approach to coordinate surgery, radiation therapy and chemotherapy. Current concepts in management, including complications of therapy, are described. State-of-the-art surgical techniques can spare patients with oral cancer from much of the morbidity and complications common in the past. The refinement of treatment strategies reduces complications and improves efficacy. Many exciting new clinical trials in the areas of gene therapy and immunomodulation are showing promise. Management of oral cancer has undergone radical change in the past 10 years and continues to evolve rapidly. Discoveries in molecular biology, diagnosis, surgery, radiation therapy and medical oncology have altered many traditional concepts and practices. General dental practitioners need to understand current treatment modalities for oral and pharyngeal cancers to determine to whom they should refer patients for the most appropriate treatment, and to make recommendations regarding complications associated with these cancers.

Tandem Wittig-ene reaction approach to kainic acid

Digital Repository Service at National Institute of Oceanography (India)

Majik, M.S.; Parameswaran, P.S.; Tilve, S.G.

The first example of a tandem Wittig-intramolecular ene reaction approach and its application toward the synthesis of kainic acid is reported. The synthetic pathway involves conversion of prenyl bromide into phosphorane 3, followed by one-pot Wittig...

Microbial Production of Short Chain Fatty Acids from Lignocellulosic Biomass: Current Processes and Market

Directory of Open Access Journals (Sweden)

Ivan Baumann

2016-01-01

Full Text Available Biological production of organic acids from conversion of biomass derivatives has received increased attention among scientists and engineers and in business because of the attractive properties such as renewability, sustainability, degradability, and versatility. The aim of the present review is to summarize recent research and development of short chain fatty acids production by anaerobic fermentation of nonfood biomass and to evaluate the status and outlook for a sustainable industrial production of such biochemicals. Volatile fatty acids (VFAs such as acetic acid, propionic acid, and butyric acid have many industrial applications and are currently of global economic interest. The focus is mainly on the utilization of pretreated lignocellulosic plant biomass as substrate (the carbohydrate route and development of the bacteria and processes that lead to a high and economically feasible production of VFA. The current and developing market for VFA is analyzed focusing on production, prices, and forecasts along with a presentation of the biotechnology companies operating in the market for sustainable biochemicals. Finally, perspectives on taking sustainable product of biochemicals from promise to market introduction are reviewed.

Current taxonomy of phages infecting lactic acid bacteria

Directory of Open Access Journals (Sweden)

Jennifer eMahony

2014-01-01

Full Text Available Phages infecting lactic acid bacteria have been the focus of significant research attention over the past three decades. Through the isolation and characterization of hundreds of phage isolates, it has been possible to classify phages of the dairy starter and adjunct bacteria Lactococus lactis, Streptococcus thermophilus, Leuconostoc spp. and Lactobacillus spp. Among these, phages of L. lactis have been most thoroughly scrutinized and serve as an excellent model system to address issues that arise when attempting taxonomic classification of phages infecting other LAB species. Here, we present an overview of the current taxonomy of phages infecting LAB genera of industrial significance, the methods employed in these taxonomic efforts and how these may be employed for the taxonomy of phages of currently underrepresented and emerging phage species.

Renal response to acute acid loading--an organ physiological approach

DEFF Research Database (Denmark)

Osther, P J; Engel, K; Kildeberg, P

2004-01-01

, as the extracellular acid-base status would be expected to be the key physiological trigger for renal NAE. The object of this study was to investigate the renal response to acute non-carbonic acid loading using a quantitative organ physiological approach. MATERIAL AND METHODS: Five-h NH4Cl loading studies were...

Hypotonic stimuli enhance proton-gated currents of acid-sensing ion channel-1b

International Nuclear Information System (INIS)

Ugawa, Shinya; Ishida, Yusuke; Ueda, Takashi; Yu, Yong; Shimada, Shoichi

2008-01-01

Acid-sensing ion channels (ASICs) are strong candidates for mammalian mechanoreceptors. We investigated whether mouse acid-sensing ion channel-1b (ASIC1b) is sensitive to mechanical stimuli using oocyte electrophysiology, because ASIC1b is located in the mechanosensory stereocilia of cochlear hair cells. Hypotonic stimuli that induced membrane stretch of oocytes evoked no significant current in ASIC1b-expressing oocytes at pH 7.5. However, acid (pH 4.0 or 5.0)-evoked currents in the oocytes were substantially enhanced by the hypotonicity, showing mechanosensitivity of ASIC1b and possible mechanogating of the channel in the presence of other components. Interestingly, the ASIC1b channel was permeable to K + (a principal charge carrier for cochlear sensory transduction) and the affinity of the channel for amiloride (IC 50 (inhibition constant) = approximately 48.3 μM) was quite similar to that described for the mouse hair cell mechanotransducer current. Taken together, these data raise the possibility that ASIC1b participates in cochlear mechanoelectrical transduction

A partial Hamiltonian approach for current value Hamiltonian systems

Science.gov (United States)

Naz, R.; Mahomed, F. M.; Chaudhry, Azam

2014-10-01

We develop a partial Hamiltonian framework to obtain reductions and closed-form solutions via first integrals of current value Hamiltonian systems of ordinary differential equations (ODEs). The approach is algorithmic and applies to many state and costate variables of the current value Hamiltonian. However, we apply the method to models with one control, one state and one costate variable to illustrate its effectiveness. The current value Hamiltonian systems arise in economic growth theory and other economic models. We explain our approach with the help of a simple illustrative example and then apply it to two widely used economic growth models: the Ramsey model with a constant relative risk aversion (CRRA) utility function and Cobb Douglas technology and a one-sector AK model of endogenous growth are considered. We show that our newly developed systematic approach can be used to deduce results given in the literature and also to find new solutions.

Amino acid neurotransmitters and new approaches to anticonvulsant drug action.

Science.gov (United States)

Meldrum, B

1984-01-01

Amino acids provide the most universal and important inhibitory (gamma-aminobutyric acid (GABA), glycine) and excitatory (glutamate, aspartate, cysteic acid, cysteine sulphinic acid) neurotransmitters in the brain. An anticonvulsant action may be produced (1) by enhancing inhibitory (GABAergic) processes, and (2) by diminishing excitatory transmission. Possible pharmacological mechanisms for enhancing GABA-mediated inhibition include (1) GABA agonist action, (2) GABA prodrugs, (3) drugs facilitating GABA release from terminals, (4) inhibition of GABA-transaminase, (5) allosteric enhancement of the efficacy of GABA at the receptor complex, (6) direction action on the chloride ionophore, and (7) inhibition of GABA reuptake. Examples of these approaches include the use of irreversible GABA-transaminase inhibitors, such as gamma-vinyl GABA, and the development of anticonvulsant beta-carbolines that interact with the "benzodiazepine receptor." Pharmacological mechanisms for diminishing excitatory transmission include (1) enzyme inhibitors that decrease the maximal rate of synthesis of glutamate or aspartate, (2) drugs that decrease the synaptic release of glutamate or aspartate, and (3) drugs that block the post-synaptic action of excitatory amino acids. Compounds that selectively antagonise excitation due to dicarboxylic amino acids have recently been developed. Those that selectively block excitation produced by N-methyl-D-aspartate (and aspartate) have proved to be potent anticonvulsants in many animal models of epilepsy. This provides a novel approach to the design of anticonvulsant drugs.

Childhood obesity: Current and novel approaches.

Science.gov (United States)

Sabin, Matthew A; Kiess, Wieland

2015-06-01

The prevalence of childhood obesity has increased over the last fifty years by approximately 5% per decade, and approximately a quarter of all children are now either overweight or obese. These children have a significantly increased risk of many future health problems including adult obesity, type 2 diabetes and heart disease. Despite this relentless increase, common-sense approaches aimed at prevention and treatment have failed to solve the problem. Current approaches at prevention have faced major challenges with some progress in implementing smaller scale programs and social marketing, but little action on broad public policy approaches which often appears unpalatable to society or individual governments. Meanwhile, treatment approaches have mainly focused on lifestyle change, and novel approaches are urgently needed. Prevention needs to shift to improving maternal health prior to conception, with more research focussed on the impact of early years in programming offspring to future overweight/obesity. Likewise, treatment paradigms need to move from simply thinking that obesity can be solved by readdressing diet and activity levels. Novel approaches are needed which take into consideration the complex physiology which regulates early childhood growth and the development of obesity in susceptible individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Endomorphins potentiate acid-sensing ion channel currents and enhance the lactic acid-mediated increase in arterial blood pressure: effects amplified in hindlimb ischaemia.

Science.gov (United States)

Farrag, Mohamed; Drobish, Julie K; Puhl, Henry L; Kim, Joyce S; Herold, Paul B; Kaufman, Marc P; Ruiz-Velasco, Victor

2017-12-01

Chronic limb ischaemia, characterized by inflammatory mediator release and a low extracellular pH, leads to acid-sensing ion channel (ASIC) activation and reflexively increases mean arterial pressure; endomorphin release is also increased under inflammatory conditions. We examined the modulation of ASIC currents by endomorphins in sensory neurons from rats with freely perfused and ligated femoral arteries: peripheral artery disease (PAD) model. Endomorphins potentiated sustained ASIC currents in both groups of dorsal root ganglion neurons, independent of mu opioid receptor stimulation or G protein activation. Intra-arterial administration of lactic acid (to simulate exercising muscle and evoke a pressor reflex), endomorphin-2 and naloxone resulted in a significantly greater pressor response than lactic acid alone, while administration of APETx2 inhibited endomorphin's enhancing effect in both groups. These results suggest a novel role for endomorphins in modulating ASIC function to effect lactic acid-mediated reflex increase in arterial pressure in patients with PAD. Chronic muscle ischaemia leads to accumulation of lactic acid and other inflammatory mediators with a subsequent drop in interstitial pH. Acid-sensing ion channels (ASICs), expressed in thin muscle afferents, sense the decrease in pH and evoke a pressor reflex known to increase mean arterial pressure. The naturally occurring endomorphins are also released by primary afferents under ischaemic conditions. We examined whether high affinity mu opioid receptor (MOR) agonists, endomorphin-1 (E-1) and -2 (E-2), modulate ASIC currents and the lactic acid-mediated pressor reflex. In rat dorsal root ganglion (DRG) neurons, exposure to E-2 in acidic solutions significantly potentiated ASIC currents when compared to acidic solutions alone. The potentiation was significantly greater in DRG neurons isolated from rats whose femoral arteries were ligated for 72 h. Sustained ASIC current potentiation was also observed

Acidic deposition: State of science and technology. Report 9. Current status of surface-water acid-base chemistry. Final report

International Nuclear Information System (INIS)

Baker, L.A.; Kaufmann, P.R.; Brakke, D.F.; Herlihy, A.T.; Eilers, J.M.

1990-09-01

The report is based largely upon the National Surface Water Survey (NSWS), augmented by numerous smaller state and university surveys and many detailed watershed studies. In describing the current status of surface waters, the authors go far beyond the description of population statistics, although some of this is necessary, and direct their attention to the interpretation of these data. They address the question of the sources of acidity to surface waters in order to determine the relative importance of acidic deposition compared with other sources, such as naturally produced organic acids and acid mine drainage. They also examine in some detail what they call 'high interest' populations-the specific groups of lakes and streams most likely to be impacted by acidic deposition. The authors then turn to the general question of uncertainty, and finally examine low alkalinity surface waters in several other parts of the world to develop further inferences about the acid-base status of surface waters in the United States

A multilayer approach for turbidity currents

Science.gov (United States)

Fernandez-Nieto, Enrique; Castro Díaz, Manuel J.; Morales de Luna, Tomás

2017-04-01

When a river that carries sediment in suspension enters into a lake or the ocean it can form a plume that can be classified as hyperpycnal or hypopycnal. Hypopycnal plumes occurs if the combined density of the sediment and interstitial fluid is lower than that of the ambient. Hyperpycnal plumes are a class of sediment-laden gravity current commonly referred to as turbidity currents [7,9]. Some layer-averaged models have been previously developed (see [3, 4, 8] among others). Although this layer-averaged approach gives a fast and valuable information, it has the disadvantage that the vertical distribution of the sediment in suspension is lost. A recent technique based on a multilayer approach [1, 2, 6] has shown to be specially useful to generalize shallow water type models in order to keep track of the vertical components of the averaged variables in the classical shallow water equations. In [5] multilayer model is obtained using a vertical discontinuous Galerkin approach for which the vertical velocity is supposed to be piecewise linear and the horizontal velocity is supposed to be piecewise constant. In this work the technique introduced in [5] is generalized to derive a model for turbidity currents. This model allows to simulate hyperpycnal as well as hypopycnal plumes. Several numerical tests will be presented. References [1] E. Audusse, M. Bristeau, B. Perthame, and J. Sainte-Marie. A multilayer Saint-Venant system with mass exchanges for shallow water flows. derivation and numerical validation. ESAIM: Mathematical Modelling and Numerical Analysis, 45(1):169-200, (2010). [2] E. Audusse, M.-O. Bristeau, M. Pelanti, and J. Sainte-Marie. Approximation of the hydrostatic Navier–Stokes system for density stratified flows by a multilayer model: Kinetic interpretation and numerical solution. Journal of Computational Physics, 230(9):3453-3478, (2011). [3] S. F. Bradford and N. D. Katopodes. Hydrodynamics of turbid underflows. i: Formulation and numerical

A new approach for noninvasive transdermal determination of blood uric acid levels

Directory of Open Access Journals (Sweden)

Ching CTS

2014-06-01

Full Text Available Congo Tak-Shing Ching,1,2 Kok-Khun Yong,3 Yan-Dong Yao,4 Huan-Ting Shen,3 Shiu-Man Hsieh,5 Deng-Yun Jheng,1 Tai-Ping Sun,1,6 Hsiu-Li Shieh11Department of Electrical Engineering, National Chi Nan University, Nantou, 2Department of Photonics and Communication Engineering, Asia University, Taichung, 3Department of Internal Medicine, Puli Christian Hospital, Nantou, People’s Republic of China; 4Division of Science and Technology, Hong Kong Community College, Hong Kong; 5Department of Orthopedic Surgery, Puli Christian Hospital, 6Department of Electronic Engineering, Nan Kai University of Technology, Nantou, People’s Republic of ChinaAbstract: The aims of this study were to investigate the most effective combination of physical forces from laser, electroporation, and reverse iontophoresis for noninvasive transdermal extraction of uric acid, and to develop a highly sensitive uric acid biosensor (UAB for quantifying the uric acid extracted. It is believed that the combination of these physical forces has additional benefits for extraction of molecules other than uric acid from human skin. A diffusion cell with porcine skin was used to investigate the most effective combination of these physical forces. UABs coated with ZnO2 nanoparticles and constructed in an array configuration were developed in this study. The results showed that a combination of laser (0.7 W, electroporation (100 V/cm2, and reverse iontophoresis (0.5 mA/cm2 was the most effective and significantly enhanced transdermal extraction of uric acid. A custom-designed UAB coated with ZnO2 nanoparticles and constructed in a 1×3 array configuration (UAB-1×3-ZnO2 demonstrated enough sensitivity (9.4 µA/mM for quantifying uric acid extracted by the combined physical forces of laser, electroporation, and RI. A good linear relationship (R2=0.894 was demonstrated to exist between the concentration of uric acid (0.2–0.8 mM inside the diffusion cell and the current response of the

Lanthanides separation by counter - current electrophoretic using α - hydroxyisobutyric acid

International Nuclear Information System (INIS)

Alleluia, I.B.

1975-01-01

Studies about counter-current electrophoretic separation of rare earth metal ions using α-hydroxyisobutyric acid as complexing electrolyte are discussed. La, Pr, Nd, Sm and Eu were separated and fractions with purities better than 99,9% were obtained, using neutron activation analysis. A relation between the first stability constant of the α-hydroxyisobutyrate/lanthanide complexes and their migration velocities were observed. (M.J.C.) [pt

Counter current extraction of phosphoric acid: Food grade acid production

International Nuclear Information System (INIS)

Shlewit, H.; AlIbrahim, M.

2009-01-01

Extraction, scrubbing and stripping of phosphoric acid from the Syrian wet-phosphoric acid was carried out using Micro-pilot plant of mixer settler type of 8 l/h capacity. Tributyl phosphate (TBP)/di-isopropyl ether (DIPE) in kerosene was used as extractant. Extraction and stripping equilibrium curves were evaluated. The number of extraction and stripping stages to achieve the convenient and feasible yield was determined. Detailed flow sheet was suggested for the proposed continuous process. Data obtained include useful information for the design of phosphoric acid extraction plant. The produced phosphoric acid was characterized using different analytical techniques. (author)

A novel approach in acidic disinfection through inhibition of acid resistance mechanisms; Maleic acid-mediated inhibition of glutamate decarboxylase activity enhances acid sensitivity of Listeria monocytogenes.

Science.gov (United States)

Paudyal, Ranju; Barnes, Ruth H; Karatzas, Kimon Andreas G

2018-02-01

Here it is demonstrated a novel approach in disinfection regimes where specific molecular acid resistance systems are inhibited aiming to eliminate microorganisms under acidic conditions. Despite the importance of the Glutamate Decarboxylase (GAD) system for survival of Listeria monocytogenes and other pathogens under acidic conditions, its potential inhibition by specific compounds that could lead to its elimination from foods or food preparation premises has not been studied. The effects of maleic acid on the acid resistance of L. monocytogenes were investigated and found that it has a higher antimicrobial activity under acidic conditions than other organic acids, while this could not be explained by its pKa or Ka values. The effects were found to be more pronounced on strains with higher GAD activity. Maleic acid affected the extracellular GABA levels while it did not affect the intracellular ones. Maleic acid had a major impact mainly on GadD2 activity as also shown in cell lysates. Furthermore, it was demonstrated that maleic acid is able to partly remove biofilms of L. monocytogenes. Maleic acid is able to inhibit the GAD of L. monocytogenes significantly enhancing its sensitivity to acidic conditions and together with its ability to remove biofilms, make a good candidate for disinfection regimes. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of the fast neutron current on the amino acid contents and nucleic acid synthesis in maize plants

International Nuclear Information System (INIS)

Akhundova, N.I.

2001-01-01

At the present time the effects of external influences on the genetic structures of the plant cells and the transmission of the accepted signals to other cellular structures and then to the whole organism have actively been studied. According to the opinion of a number of authors the gene expression and repression are immediate responses to the environment changes. To affect the plant genetic apparatus it is quite enough to expose it to some factors such as gamma rays, X- rays, neutron currents, saline-, temperature- or osmotic stresses. At the current stage of the research of the molecular mechanisms of the plant adaptation to the environment changes the priority goal is to ascertain the nature of the influence of the above mentioned factors on the processes of DNA replication and transcription, as the nucleic acids are the targets for external effects. The fast neutron current is one of the factors that influence the plant growth and development. Unlike gamma rays, the mechanism of the neutron irradiation on the plant genetic apparatus is very poorly studied. The objective of our research was the study of the fast neutron current effects on the DNA replication and transcription processes and amino acid synthesis in the irradiated maize plants

Limiting Current of Oxygen Reduction on Gas-Diffusion Electrodes for Phosphoric Acid Fuel Cells

DEFF Research Database (Denmark)

Li, Qingfeng; Gang, Xiao; Hjuler, Hans Aage

1994-01-01

on polytetrafluorine-ethyl bonded gas-diffusion electordes in phosphoric acid with and without fluorinated additives. This provides an alternative to estimate the film thickness by combining it with the acid-adsorption measurements and the porosity analysis of the catalyst layer. It was noticed that the limiting......Various models have been devoted to the operation mechanism of porous diffusion electrodes. They are, however, suffering from the lack of accuracy concerning the acid-film thickness on which they are based. In the present paper the limiting current density has been measured for oxygen reduction...... current density can be accomplished either by gas-phase diffusion or liquid-phase diffusion, and it is the latter that can be used in the film-thickness estimation. It is also important to mention that at such a limiting condition, both the thin-film model and the filmed agglomerate model reach the same...

PCI-GC-MS-MS approach for identification of non-amino organic acid and amino acid profiles.

Science.gov (United States)

Luan, Hemi; Yang, Lin; Ji, Fenfen; Cai, Zongwei

2017-03-15

Alkyl chloroformate have been wildly used for the fast derivatization of metabolites with amino and/or carboxyl groups, coupling of powerful separation and detection systems, such as GC-MS, which allows the comprehensive analysis of non-amino organic acids and amino acids. The reagents involving n-alkyl chloroformate and n-alcohol are generally employed for providing symmetric labeling terminal alkyl chain with the same length. Here, we developed an asymmetric labeling strategy and positive chemical ionization gas chromatography-tandem mass spectrometry (PCI-GC-MS-MS) approach for determination of non-amino organic acids and amino acids, as well as the short chain fatty acids. Carboxylic and amino groups could be selectively labelled by propyl and ethyl groups, respectively. The specific neutral loss of C 3 H 8 O (60Da), C 3 H 5 O 2 (74Da) and C 4 H 8 O 2 (88Da) were useful in the selective identification for qualitative analysis of organic acids and amino acid derivatives. PCI-GC-MS-MS using multiple reaction monitoring (MRM) was applied for semi-quantification of typical non-amino organic acids and amino acids. This method exhibited a wide range of linear range, good regression coefficient (R 2 ) and repeatability. The relative standard deviation (RSD) of targeted metabolites showed excellent intra- and inter-day precision (chloroformate derivatization. Copyright © 2016 Elsevier B.V. All rights reserved.

Separation of phenolic acids from sugarcane rind by online solid-phase extraction with high-speed counter-current chromatography.

Science.gov (United States)

Geng, Ping; Fang, Yingtong; Xie, Ronglong; Hu, Weilun; Xi, Xingjun; Chu, Qiao; Dong, Genlai; Shaheen, Nusrat; Wei, Yun

2017-02-01

Sugarcane rind contains some functional phenolic acids. The separation of these compounds from sugarcane rind is able to realize the integrated utilization of the crop and reduce environment pollution. In this paper, a novel protocol based on interfacing online solid-phase extraction with high-speed counter-current chromatography (HSCCC) was established, aiming at improving and simplifying the process of phenolic acids separation from sugarcane rind. The conditions of online solid-phase extraction with HSCCC involving solvent system, flow rate of mobile phase as well as saturated extent of absorption of solid-phase extraction were optimized to improve extraction efficiency and reduce separation time. The separation of phenolic acids was performed with a two-phase solvent system composed of butanol/acetic acid/water at a volume ratio of 4:1:5, and the developed online solid-phase extraction with HSCCC method was validated and successfully applied for sugarcane rind, and three phenolic acids including 6.73 mg of gallic acid, 10.85 mg of p-coumaric acid, and 2.78 mg of ferulic acid with purities of 60.2, 95.4, and 84%, respectively, were obtained from 150 mg sugarcane rind crude extracts. In addition, the three different elution methods of phenolic acids purification including HSCCC, elution-extrusion counter-current chromatography and back-extrusion counter-current chromatography were compared. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rheological evaluation of simulated neutralized current acid waste

International Nuclear Information System (INIS)

Fow, C.L.; McCarthy, D.; Thornton, G.T.

1986-06-01

A byproduct of the Purex process is an aqueous waste stream that contains fission products. This waste stream, called current acid waste, is chemically neutralized and stored in double shell tanks on the Hanford Site. This neutralized current acid waste (NCAW) will be transported by pipe to B-Plant, a processing plant on the Hanford Site. Rheological and transport properties of NCAW slurry were evaluated. First, researchers conducted lab rheological evaluations of simulated NCAW. The results of these evaluations were then correlated with classical rheological models and scaled up to predict the performance that is likely to occur in the full-scale system. The NCAW in the tank will either be retrieved as is, i.e., no change in the concentration presently in the tank, or will be slightly concentrated before retrieval. Sluicing may be required to retrieve the solids. Three concentrations of simulated NCAW were evaluated that would simulate the different retrieval options: NCAW in the concentration that is presently in the tank; a slightly concentrated NCAW, called NCAW5.5; and equal parts of NCAW settled solids and water (simulating the sluicing stage), called NCAW1:1. The physical and rheological properties of three samples of each concentration at 25 and 100 0 C were evaluated in the laboratory. The properties displayed by NCAW and NCAW5.5 at 25 and 100 0 C allowed it to be classified as a pseudoplastic non-Newtonian fluid. NCAW1:1 at 25 and 100 0 C displayed properties of a yield-pseudoplastic non-Newtonian fluid. The classical non-Newtonian models for pseudoplastic and yield-pseudoplastic fluids were used with the laboratory data to predict the full-scale pump-pipe network parameters

Incorporation of post-translational modified amino acids as an approach to increase both chemical and biological diversity of conotoxins and conopeptides.

Science.gov (United States)

Espiritu, Michael J; Cabalteja, Chino C; Sugai, Christopher K; Bingham, Jon-Paul

2014-01-01

Bioactive peptides from Conus venom contain a natural abundance of post-translational modifications that affect their chemical diversity, structural stability, and neuroactive properties. These modifications have continually presented hurdles in their identification and characterization. Early endeavors in their analysis relied on classical biochemical techniques that have led to the progressive development and use of novel proteomic-based approaches. The critical importance of these post-translationally modified amino acids and their specific assignment cannot be understated, having impact on their folding, pharmacological selectivity, and potency. Such modifications at an amino acid level may also provide additional insight into the advancement of conopeptide drugs in the quest for precise pharmacological targeting. To achieve this end, a concerted effort between the classical and novel approaches is needed to completely elucidate the role of post-translational modifications in conopeptide structure and dynamics. This paper provides a reflection in the advancements observed in dealing with numerous and multiple post-translationally modified amino acids within conotoxins and conopeptides and provides a summary of the current techniques used in their identification.

Molecular acidity: An accurate description with information-theoretic approach in density functional reactivity theory.

Science.gov (United States)

Cao, Xiaofang; Rong, Chunying; Zhong, Aiguo; Lu, Tian; Liu, Shubin

2018-01-15

Molecular acidity is one of the important physiochemical properties of a molecular system, yet its accurate calculation and prediction are still an unresolved problem in the literature. In this work, we propose to make use of the quantities from the information-theoretic (IT) approach in density functional reactivity theory and provide an accurate description of molecular acidity from a completely new perspective. To illustrate our point, five different categories of acidic series, singly and doubly substituted benzoic acids, singly substituted benzenesulfinic acids, benzeneseleninic acids, phenols, and alkyl carboxylic acids, have been thoroughly examined. We show that using IT quantities such as Shannon entropy, Fisher information, Ghosh-Berkowitz-Parr entropy, information gain, Onicescu information energy, and relative Rényi entropy, one is able to simultaneously predict experimental pKa values of these different categories of compounds. Because of the universality of the quantities employed in this work, which are all density dependent, our approach should be general and be applicable to other systems as well. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Rheological evaluation of simulated neutralized current acid waste - transuranics

International Nuclear Information System (INIS)

Fow, C.L.; McCarthy, D.; Thornton, G.T.; Scott, P.A.; Bray, L.A.

1986-09-01

At the Hanford Plutonium and Uranium Extraction Plant (PUREX), in Richland, Washington, plutonium and uranium products are recovered from irradiated fuel by a solvent extraction process. A byproduct of this process is an aqueous waste stream that contains fission products. This waste stream, called current acid waste (CAW), is chemically neutralized and stored in double shell tanks (DSTs) on the Hanford Site. This neutralized current acid waste (NCAW) will be transported by pipe to B-Plant, a processing plant located nearby. In B-Plant, the transuranic (TRU) elements in NCAW are separated from the non-TRU elements. The majority of the TRU elements in NCAW are in the solids. Therefore, the primary processing operation is to separate the NCAW solids (NCAW-TRU) from the NCAW liquid. These two waste streams will be pumped to suitable holding tanks before being further processed for permanent disposal. To ensure that the retrieval and transportation of NCAW and NCAW-TRU are successful, researchers at Pacific Northwest Laboratory (PNL) evaluated the rheological and transport properties of the slurries. This evaluation had two phases. First, researchers conducted laboratory rheological evaluations of simulated NCAW and NCAW-TRU. The results of these evaluations were then correlated with classical rheological models and scaled up to predict the performance that is likely to occur in the full-scale system. This scale-up procedure has already been successfully used to predict the critical transport properties of a slurry (Neutralized Cladding Removal Waste) with rheological properties similar to those displayed by NCAW and NCAW-TRU

Current approach to liver traumas.

Science.gov (United States)

Kaptanoglu, Levent; Kurt, Necmi; Sikar, Hasan Ediz

2017-03-01

Liver injuries remain major obstacle for successful treatment, due to size and location of the liver. Requirement for surgery should be determined by clinical factors, most notably hemodynamical state. In this present study we tried to declare our approach to liver traumas. We also tried to emphasize the importance of conservative treatment, since surgeries for liver traumas carry high mortality rates. Patients admitted to the Department of Emergency Surgery at Kartal Research and Education Hospital, due to liver trauma were retrospectively analyzed between 2003 and 2013. Patient demographics, hepatic panel, APTT (activated partial thromboplastin time), PT (prothrombin time), INR (international normalized ratio), fibrinogen, biochemistry panel were recorded. Hemodynamic instability was the most prominent factor for surgery decision, in the lead of current Advanced Trauma Life Support (ATLS) protocols. Operation records and imaging modalities revealed liver injuries according to the Organ Injury Scale of the American Association for the Surgery of Trauma. 300 patients admitted to emergency department were included in our study (187 males and 113 females). Mean age was 47 years (range, 12-87). The overall mortality rate was 13% (40 out of 300). Major factor responsible for mortality rates and outcome was stability of cases on admission. 188 (% 63) patients were counted as stable, whereas 112 (% 37) cases were found unstable (blood pressure ≤ 90, after massive resuscitation). 192 patients were observed conservatively, whereas 108 cases received abdominal surgery. High levels of AST, ALT, LDH, INR, creatinine and low levels of fibrinogen and low platelet counts on admission were found to be associated with mortality and these cases also had Grade 4 and 5 injuries. Hemodynamic instability on admission and the type and grade of injury played major role in mortality rates). Packing was performed in 35 patients, with Grade 4 and 5 injuries. Mortality rate was %13 (40

Neutralized current acid waste consolidation management plan

International Nuclear Information System (INIS)

Powell, W.J.; Brown, R.G.; Galbraith, J.; Jensen, C.; Place, D.E.; Reddick, G.W.; Zuroff, W.; Brothers, A.J.

1996-01-01

The scope of this evaluation is to recommend a management plan for the high-heat tank waste, including neutralized current acid waste (NCAW) in AY and AZ Tank Farms, and tank C-106 waste. The movement of solids, liquids and salt cake in the designated tank farms is included. Decision analysis techniques were used to determine a recommended alternative. The recommended course of action was replacement of a 75-hp mixer pump in tank AY-102 and in-tank concentration of tank AZ-102 supernate. The alternative includes transfer fo tank C-106 sludge to tank AY-102, then transfer to tank AY-102 and tank C-106 sludge to tank AZ-101 using the new 75-hp mixer pump installed in tank AY-102. Tank AZ-101 becomes a storage tank for high-level waste (HLW) sludge, with the capacity to mix and transfer sludge as desired

ENVIRONMENTAL LEARNING APPROACHES IN IMPROVING LEARNING OUTCOMES IN ACID-BASE SUBJECT

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Rachmat Sahputra

2016-03-01

Full Text Available Learning in the understanding of acid-base chemistry in schools needs to be improved so research to determine differences in learning outcomes between students taught using environmental approaches and methods lectures in class XI SMA on acid-base subject needs to be done. In this study, using a quasi-experimental method using a data collection tool achievement test essay form. The test statistic results of the post-test learning has been obtained Asymp value. Sig (2-tailed 0,026 that showed the differences between students' learning outcomes with a control experimental class with effect size of 0.63 or much influence difference with the percentage 23.57% which indicated that the learning environment approach can improve learning outcomes of high school students.

Migration of antioxidants from polylactic acid films: A parameter estimation approach and an overview of the current mass transfer models.

Science.gov (United States)

Samsudin, Hayati; Auras, Rafael; Mishra, Dharmendra; Dolan, Kirk; Burgess, Gary; Rubino, Maria; Selke, Susan; Soto-Valdez, Herlinda

2018-01-01

Migration studies of chemicals from contact materials have been widely conducted due to their importance in determining the safety and shelf life of a food product in their packages. The US Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) require this safety assessment for food contact materials. So, migration experiments are theoretically designed and experimentally conducted to obtain data that can be used to assess the kinetics of chemical release. In this work, a parameter estimation approach was used to review and to determine the mass transfer partition and diffusion coefficients governing the migration process of eight antioxidants from poly(lactic acid), PLA, based films into water/ethanol solutions at temperatures between 20 and 50°C. Scaled sensitivity coefficients were calculated to assess simultaneously estimation of a number of mass transfer parameters. An optimal experimental design approach was performed to show the importance of properly designing a migration experiment. Additional parameters also provide better insights on migration of the antioxidants. For example, the partition coefficients could be better estimated using data from the early part of the experiment instead at the end. Experiments could be conducted for shorter periods of time saving time and resources. Diffusion coefficients of the eight antioxidants from PLA films were between 0.2 and 19×10 -14 m 2 /s at ~40°C. The use of parameter estimation approach provided additional and useful insights about the migration of antioxidants from PLA films. Copyright © 2017 Elsevier Ltd. All rights reserved.

A review on the current status and production technology of 32,33P-orthophosphoric acid

International Nuclear Information System (INIS)

Park, Ul Jae; Han, Hyun Soo; Cho, Woon Kap; Kuznetsov, Rostislav A.

2000-10-01

The current status of 32 , 33 P-Orthophosphoric acid production technology is reviewed. The following aspects of the technology are covered: - production of phosphorus-32 and phosphorus-33 using various nuclear reactions; - chemical properties of sulfur and phosphorus effecting the technology of radioactive phosphorus production; - chemical state of 32 , 33 P in neutron irradiated sulfur; - the technology of radioactive phosphorus isolation from neutron irradiated target and orthophosphoric acid production; - purification of 32 , 33 P-orthophosphoric acid from impurities and some related problems, like the nature of impurities, the storage of the final product, etc. - the quality control procedures of carrier-free ( 32 , 33 P)-orthophosphoric acid preparations

Current Therapeutic Strategies and Novel Approaches in Osteosarcoma

International Nuclear Information System (INIS)

Ando, Kosei; Heymann, Marie-Françoise; Stresing, Verena; Mori, Kanji; Rédini, Françoise; Heymann, Dominique

2013-01-01

Osteosarcoma is the most frequent malignant primary bone tumor and a main cause of cancer-related death in children and adolescents. Although long-term survival in localized osteosarcoma has improved to about 60% during the 1960s and 1970s, long-term survival in both localized and metastatic osteosarcoma has stagnated in the past several decades. Thus, current conventional therapy consists of multi-agent chemotherapy, surgery and radiation, which is not fully adequate for osteosarcoma treatment. Innovative drugs and approaches are needed to further improve outcome in osteosarcoma patients. This review describes the current management of osteosarcoma as well as potential new therapies

Nucleic Acid-Based Therapy Approaches for Huntington's Disease

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Tatyana Vagner

2012-01-01

Full Text Available Huntington's disease (HD is caused by a dominant mutation that results in an unstable expansion of a CAG repeat in the huntingtin gene leading to a toxic gain of function in huntingtin protein which causes massive neurodegeneration mainly in the striatum and clinical symptoms associated with the disease. Since the mutation has multiple effects in the cell and the precise mechanism of the disease remains to be elucidated, gene therapy approaches have been developed that intervene in different aspects of the condition. These approaches include increasing expression of growth factors, decreasing levels of mutant huntingtin, and restoring cell metabolism and transcriptional balance. The aim of this paper is to outline the nucleic acid-based therapeutic strategies that have been tested to date.

[Current situation and impact factors of acid deposition in main cites of Shandong Province].

Science.gov (United States)

Jia, Hong-yu; Zhang, Qiao-xian; Deng, Hong-bing; Zhao, Jing-zhu; Mu, Jin-bo; Zhang, De-zhi

2006-12-01

Based on the monitoring data for years in Shandong Province, current situation of acid rain in every city was assessed, and the temporal distribution of the dry, wet and total sulfur deposition in Jinan and Qingdao were studied. The results showed that Qingdao which had the largest precipitation acidity was the single city whose annul average precipitation pH was below 5. 60. The precipitation acidities in the main cities of Shandong Province were in a descent tendency. The total sulfur desposition in Jinan and Qingdao was basically stable or in a descent tendency, but also reached 10 t/(km(2)x a) or so. Among the total sulfur deposition flux, the dry deposition of sulfur had the greater contribution, and the contribution of SO2 dry deposition was higher than that of SO42- dry deposition. By analyzing the relation between the precipitation acidity and the SO2 discharge intensity, soil acidity and meteorological condition, the impact factors of acid precipitation in the cities of Shandong Province were revealed.

Multi-omics approach to study the growth efficiency and amino acid metabolism in Lactococcus lactis at various specific growth rates

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Arike Liisa

2011-02-01

Full Text Available Abstract Background Lactococcus lactis is recognised as a safe (GRAS microorganism and has hence gained interest in numerous biotechnological approaches. As it is fastidious for several amino acids, optimization of processes which involve this organism requires a thorough understanding of its metabolic regulations during multisubstrate growth. Results Using glucose limited continuous cultivations, specific growth rate dependent metabolism of L. lactis including utilization of amino acids was studied based on extracellular metabolome, global transcriptome and proteome analysis. A new growth medium was designed with reduced amino acid concentrations to increase precision of measurements of consumption of amino acids. Consumption patterns were calculated for all 20 amino acids and measured carbon balance showed good fit of the data at all growth rates studied. It was observed that metabolism of L. lactis became more efficient with rising specific growth rate in the range 0.10 - 0.60 h-1, indicated by 30% increase in biomass yield based on glucose consumption, 50% increase in efficiency of nitrogen use for biomass synthesis, and 40% reduction in energy spilling. The latter was realized by decrease in the overall product formation and higher efficiency of incorporation of amino acids into biomass. L. lactis global transcriptome and proteome profiles showed good correlation supporting the general idea of transcription level control of bacterial metabolism, but the data indicated that substrate transport systems together with lower part of glycolysis in L. lactis were presumably under allosteric control. Conclusions The current study demonstrates advantages of the usage of strictly controlled continuous cultivation methods combined with multi-omics approach for quantitative understanding of amino acid and energy metabolism of L. lactis which is a valuable new knowledge for development of balanced growth media, gene manipulations for desired product

Determination of complex formation constants by phase sensitive alternating current polarography: Cadmium-polymethacrylic acid and cadmium-polygalacturonic acid.

Science.gov (United States)

Garrigosa, Anna Maria; Gusmão, Rui; Ariño, Cristina; Díaz-Cruz, José Manuel; Esteban, Miquel

2007-10-15

The use of phase sensitive alternating current polarography (ACP) for the evaluation of complex formation constants of systems where electrodic adsorption is present has been proposed. The applicability of the technique implies the previous selection of the phase angle where contribution of capacitive current is minimized. This is made using Multivariate Curve Resolution by Alternating Least Squares (MCR-ALS) in the analysis of ACP measurements at different phase angles. The method is checked by the study of the complexation of Cd by polymethacrylic (PMA) and polygalacturonic (PGA) acids, and the optimal phase angles have been ca. -10 degrees for Cd-PMA and ca. -15 degrees for Cd-PGA systems. The goodness of phase sensitive ACP has been demonstrated comparing the determined complex formation constants with those obtained by reverse pulse polarography, a technique that minimizes the electrode adsorption effects on the measured currents.

Comparing Teaching Approaches About Maxwell's Displacement Current

Science.gov (United States)

Karam, Ricardo; Coimbra, Debora; Pietrocola, Maurício

2014-08-01

Due to its fundamental role for the consolidation of Maxwell's equations, the displacement current is one of the most important topics of any introductory course on electromagnetism. Moreover, this episode is widely used by historians and philosophers of science as a case study to investigate several issues (e.g. the theory-experiment relationship). Despite the consensus among physics educators concerning the relevance of the topic, there are many possible ways to interpret and justify the need for the displacement current term. With the goal of understanding the didactical transposition of this topic more deeply, we investigate three of its domains: (1) The historical development of Maxwell's reasoning; (2) Different approaches to justify the term insertion in physics textbooks; and (3) Four lectures devoted to introduce the topic in undergraduate level given by four different professors. By reflecting on the differences between these three domains, significant evidence for the knowledge transformation caused by the didactization of this episode is provided. The main purpose of this comparative analysis is to assist physics educators in developing an epistemological surveillance regarding the teaching and learning of the displacement current.

Microalgal biofactories: a promising approach towards sustainable omega-3 fatty acid production

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Adarme-Vega T

2012-07-01

Full Text Available Abstract Omega-3 fatty acids eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA provide significant health benefits and this has led to an increased consumption as dietary supplements. Omega-3 fatty acids EPA and DHA are found in animals, transgenic plants, fungi and many microorganisms but are typically extracted from fatty fish, putting additional pressures on global fish stocks. As primary producers, many marine microalgae are rich in EPA (C20:5 and DHA (C22:6 and present a promising source of omega-3 fatty acids. Several heterotrophic microalgae have been used as biofactories for omega-3 fatty acids commercially, but a strong interest in autotrophic microalgae has emerged in recent years as microalgae are being developed as biofuel crops. This paper provides an overview of microalgal biotechnology and production platforms for the development of omega-3 fatty acids EPA and DHA. It refers to implications in current biotechnological uses of microalgae as aquaculture feed and future biofuel crops and explores potential applications of metabolic engineering and selective breeding to accumulate large amounts of omega-3 fatty acids in autotrophic microalgae.

Evaluation of different approaches for modeling effects of acid rain on soils in China

International Nuclear Information System (INIS)

Larssen, T.; Schnoor, J.L.; Seip, H.M.; Dawei, Z.

2000-01-01

Acid deposition is an environmental problem of increasing concern in China. Acidic soils are common in the southern part of the country and soil acidification caused by acid deposition is expected to occur. Here we test and apply two different approaches for modeling effects of acid deposition and compare results with observed data from sites throughout southern China. The dynamic model MAGIC indicates that, during the last few decades, soil acidification rates have increased considerably due to acid deposition. This acidification will continue if sulfur deposition is not reduced, and if reduced more rapidly than base cation deposition. With the Steady State Mass Balance model (SSMB), and assuming that a molar ratio of Ca 2+ /Al 3+ <1 in soil water is harmful to vegetation, we estimate a slight probability for exceedance of the critical load for present deposition rates. Results from both modeling approaches show a strong dependence with deposition of base cations as well as sulfur. Hence, according to the models, changes in emission control of alkaline particulate matter prior to sulfur dioxide will be detrimental to the environment. Model calculations are, however, uncertain, particularly because available data on base cation deposition fluxes are scarce, and that model formulation of aluminum chemistry does not fully reproduce observations. An effort should be made to improve our present knowledge regarding deposition fluxes. Improvements to the model are suggested. Our work indicates that the critical loads presented in the regional acid deposition assessment model RAINS-Asia are too stringent. We find weaknesses in the SSMB approach, developed for northern European conditions, when applying it to Chinese conditions. We suggest an improved effort to revise the risk parameters for use in critical load estimates in China

Electrostatic Discharge Current Linear Approach and Circuit Design Method

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Pavlos K. Katsivelis

2010-11-01

Full Text Available The Electrostatic Discharge phenomenon is a great threat to all electronic devices and ICs. An electric charge passing rapidly from a charged body to another can seriously harm the last one. However, there is a lack in a linear mathematical approach which will make it possible to design a circuit capable of producing such a sophisticated current waveform. The commonly accepted Electrostatic Discharge current waveform is the one set by the IEC 61000-4-2. However, the over-simplified circuit included in the same standard is incapable of producing such a waveform. Treating the Electrostatic Discharge current waveform of the IEC 61000-4-2 as reference, an approximation method, based on Prony’s method, is developed and applied in order to obtain a linear system’s response. Considering a known input, a method to design a circuit, able to generate this ESD current waveform in presented. The circuit synthesis assumes ideal active elements. A simulation is carried out using the PSpice software.

Towards Current Profile Control in ITER: Potential Approaches and Research Needs

Science.gov (United States)

Schuster, E.; Barton, J. E.; Wehner, W. P.

2014-10-01

Many challenging plasma control problems still need to be addressed in order for the ITER Plasma Control System (PCS) to be able to successfully achieve the ITER project goals. For instance, setting up a suitable toroidal current density profile is key for one possible advanced scenario characterized by noninductive sustainment of the plasma current and steady-state operation. The nonlinearity and high dimensionality exhibited by the plasma demand a model-based current-profile control synthesis procedure that can accommodate this complexity through embedding the known physics within the design. The development of a model capturing the dynamics of the plasma relevant for control design enables not only the design of feedback controllers for regulation or tracking but also the design of optimal feedforward controllers for a systematic model-based approach to scenario planning, the design of state estimators for a reliable real-time reconstruction of the plasma internal profiles based on limited and noisy diagnostics, and the development of a fast predictive simulation code for closed-loop performance evaluation before implementation. Progress towards control-oriented modeling of the current profile evolution and associated control design has been reported following both data-driven and first-principles-driven approaches. An overview of these two approaches will be provided, as well as a discussion on research needs associated with each one of the model applications described above. Supported by the US Department of Energy under DE-SC0001334 and DE-SC0010661.

Tetramer model of leukoemeraldine-emeraldine electrochemistry in the presence of trihalogenoacetic acids. DFT approach.

Science.gov (United States)

Barbosa, Nuno Almeida; Grzeszczuk, Maria; Wieczorek, Robert

2015-01-15

First results of the application of the DFT computational approach to the reversible electrochemistry of polyaniline are presented. A tetrameric chain was used as the simplest model of the polyaniline polymer species. The system under theoretical investigation involved six tetramer species, two electrons, and two protons, taking part in 14 elementary reactions. Moreover, the tetramer species were interacting with two trihalogenoacetic acid molecules. Trifluoroacetic, trichloroacetic, and tribromoacetic acids were found to impact the redox transformation of polyaniline as shown by cyclic voltammetry. The theoretical approach was considered as a powerful tool for investigating the main factors of importance for the experimental behavior. The DFT method provided molecular structures, interaction energies, and equilibrium energies of all of the tetramer-acid complexes. Differences between the energies of the isolated tetramer species and their complexes with acids are discussed in terms of the elementary reactions, that is, ionization potentials and electron affinities, equilibrium constants, electrode potentials, and reorganization energies. The DFT results indicate a high impact of the acid on the reorganization energy of a particular elementary electron-transfer reaction. The ECEC oxidation path was predicted by the calculations. The model of the reacting system must be extended to octamer species and/or dimeric oligomer species to better approximate the real polymer situation.

Electroplated reticulated vitreous carbon current collectors for lead-acid batteries: opportunities and challenges

Science.gov (United States)

Gyenge, Elod; Jung, Joey; Mahato, Basanta

Reticulated, open-cell structures based on vitreous carbon substrates electroplated with a Pb-Sn (1 wt.%) alloy were investigated as current collectors for lead-acid batteries. Scanning and backscattered electron microscopy, cyclic voltammetry, anodic polarization and flooded 2 V single-cell battery testing was employed to characterize the performance of the proposed collectors. A battery equipped with pasted electroplated reticulated vitreous carbon (RVC) electrodes of 137 cm 2 geometric area, at the time of manuscript submission, completed 500 cycles and over 1500 h of continuous operation. The cycling involved discharges at 63 A kg PAM-1 corresponding to a nominal 0.75 h rate and a positive active mass (PAM) utilization efficiency of 21%. The charging protocol was composed of two voltage limited (i.e. 2.6 V/cell), constant current steps of 35 and 9.5 A kg PAM-1, respectively, with a total duration of about 2 h. The charge factor was 1.05-1.15. The observed cycling behavior in conjunction with the versatility of electrodeposition to produce application-dependent optimized lead alloy coating thickness and composition shows promise for the development of lead-acid batteries using electroplated reticulated vitreous carbon collectors.

New approaches to male non-hormonal contraception.

Science.gov (United States)

Nya-Ngatchou, Jean-Jacques; Amory, John K

2013-03-01

A non-hormonal male contraceptive is a contraceptive that does not involve the administration of hormones or hormone blockers. This review will focus on the use of lonidamine derivatives and inhibitors of retinoic acid biosynthesis and function as approaches to male non-hormonal contraception. Two current lonidamine derivatives, adjudin and H2-gamendazole, are in development as male contraceptives. These potent anti-spermatogenic compounds impair the integrity of the apical ectoplasmic specialization, resulting in premature spermiation and infertility. Another approach to male contraceptive development is the inhibition of retinoic acid in the testes, as retinoic acid signaling is necessary for spermatogenesis. The administration of the retinoic acid receptor antagonist BMS-189453 reversibly inhibits spermatogenesis in mice. Similarly, oral dosing of WIN 18,446, which inhibits testicular retinoic acid biosynthesis, effectively contracepts rabbits. Hopefully, one of these approaches to non-hormonal male contraception will prove to be safe and effective in future clinical trials. Copyright © 2013 Elsevier Inc. All rights reserved.

Has Stewart approach improved our ability to diagnose acid-base disorders in critically ill patients?

Science.gov (United States)

Masevicius, Fabio D; Dubin, Arnaldo

2015-02-04

The Stewart approach-the application of basic physical-chemical principles of aqueous solutions to blood-is an appealing method for analyzing acid-base disorders. These principles mainly dictate that pH is determined by three independent variables, which change primarily and independently of one other. In blood plasma in vivo these variables are: (1) the PCO2; (2) the strong ion difference (SID)-the difference between the sums of all the strong (i.e., fully dissociated, chemically nonreacting) cations and all the strong anions; and (3) the nonvolatile weak acids (Atot). Accordingly, the pH and the bicarbonate levels (dependent variables) are only altered when one or more of the independent variables change. Moreover, the source of H(+) is the dissociation of water to maintain electroneutrality when the independent variables are modified. The basic principles of the Stewart approach in blood, however, have been challenged in different ways. First, the presumed independent variables are actually interdependent as occurs in situations such as: (1) the Hamburger effect (a chloride shift when CO2 is added to venous blood from the tissues); (2) the loss of Donnan equilibrium (a chloride shift from the interstitium to the intravascular compartment to balance the decrease of Atot secondary to capillary leak; and (3) the compensatory response to a primary disturbance in either independent variable. Second, the concept of water dissociation in response to changes in SID is controversial and lacks experimental evidence. In addition, the Stewart approach is not better than the conventional method for understanding acid-base disorders such as hyperchloremic metabolic acidosis secondary to a chloride-rich-fluid load. Finally, several attempts were performed to demonstrate the clinical superiority of the Stewart approach. These studies, however, have severe methodological drawbacks. In contrast, the largest study on this issue indicated the interchangeability of the Stewart and

Current diagnostic approaches to subarachnoid haemorrhage

International Nuclear Information System (INIS)

U-King-Im, Jean Marie; Koo, Brendan; Trivedi, Rikin A.; Higgins, Nicholas J.; Tay, Keng Y.; Cross, Justin J.; Antoun, Nagui M.; Gillard, Jonathan H.

2005-01-01

Over the past decade, significant advances have been made in the field of subarachnoid haemorrhage (SAH). Prompt diagnosis with high-resolution CT and intensive critical care support remain key aspects of good patient management. Early identification and definitive treatment of underlying ruptured aneurysms is generally advocated to reduce the risk of re-bleeding, a complication with high mortality and morbidity. Although intra-arterial digital subtraction angiography (DSA) is still considered the gold standard for sourcing aneurysms, CT angiography, especially with the evolution of multi-slice technology, is slowly gaining acceptance as a rapid, accessible and minimally invasive method which appears likely to replace DSA as first-line modality in the future. Furthermore, the advent of Guglielmi detachable coils and the ISAT trial have revolutionised the treatment of ruptured aneurysms, with a significant trend towards endovascular coiling away from operative clipping. Improvements in clinical experience, coiling technology and assistive devices now allow interventionalists to potentially treat the majority of aneurysms, including wide-necked or complex lesions. The uncertain long-term results of coiling, however, still fuel strong debate and controversy. This review summarises current diagnostic approaches to SAH from a radiological perspective, with an emphasis on aneurysmal SAH and an evidence-based approach to the role of imaging and interventional radiology in diagnosis, treatment and follow-up. (orig.)

Current diagnostic approaches to subarachnoid haemorrhage

Energy Technology Data Exchange (ETDEWEB)

U-King-Im, Jean Marie; Koo, Brendan; Trivedi, Rikin A.; Higgins, Nicholas J.; Tay, Keng Y.; Cross, Justin J.; Antoun, Nagui M.; Gillard, Jonathan H. [Addenbrooke' s Hospital, University Department of Radiology, Cambridge (United Kingdom)

2005-06-01

Over the past decade, significant advances have been made in the field of subarachnoid haemorrhage (SAH). Prompt diagnosis with high-resolution CT and intensive critical care support remain key aspects of good patient management. Early identification and definitive treatment of underlying ruptured aneurysms is generally advocated to reduce the risk of re-bleeding, a complication with high mortality and morbidity. Although intra-arterial digital subtraction angiography (DSA) is still considered the gold standard for sourcing aneurysms, CT angiography, especially with the evolution of multi-slice technology, is slowly gaining acceptance as a rapid, accessible and minimally invasive method which appears likely to replace DSA as first-line modality in the future. Furthermore, the advent of Guglielmi detachable coils and the ISAT trial have revolutionised the treatment of ruptured aneurysms, with a significant trend towards endovascular coiling away from operative clipping. Improvements in clinical experience, coiling technology and assistive devices now allow interventionalists to potentially treat the majority of aneurysms, including wide-necked or complex lesions. The uncertain long-term results of coiling, however, still fuel strong debate and controversy. This review summarises current diagnostic approaches to SAH from a radiological perspective, with an emphasis on aneurysmal SAH and an evidence-based approach to the role of imaging and interventional radiology in diagnosis, treatment and follow-up. (orig.)

A review on the current status and production technology of {sup 32,} {sup 33}P-orthophosphoric acid

Energy Technology Data Exchange (ETDEWEB)

Park, Ul Jae; Han, Hyun Soo; Cho, Woon Kap; Kuznetsov, Rostislav A

2000-10-01

The current status of {sup 32}, {sup 33}P-Orthophosphoric acid production technology is reviewed. The following aspects of the technology are covered: - production of phosphorus-32 and phosphorus-33 using various nuclear reactions; - chemical properties of sulfur and phosphorus effecting the technology of radioactive phosphorus production; - chemical state of {sup 32}, {sup 33}P in neutron irradiated sulfur; - the technology of radioactive phosphorus isolation from neutron irradiated target and orthophosphoric acid production; - purification of {sup 32}, {sup 33}P-orthophosphoric acid from impurities and some related problems, like the nature of impurities, the storage of the final product, etc. - the quality control procedures of carrier-free ({sup 32}, {sup 33}P)-orthophosphoric acid preparations.

A facile physical approach to make chitosan soluble in acid-free water.

Science.gov (United States)

Fu, Yinghao; Xiao, Congming

2017-10-01

We changed the situation that chitosan was only dissolved in diluted acid through mild physical treatment. In viewing of the usual methods to modify chitosan are chemical ones, we established the approach by using a water-soluble chitosan derivative as the model polymer. Its water-solubility was modulated via changing the concentration of solution and varying the precipitants. Such a physical method was adopted to treat chitiosan. One gram chitosan was dissolved in a mixture of 100mL 10% acetic acid and 50mL methanol, and then precipitated from a precipitant consisted of 10mL ethanol and 90mL acetate ester. The treated chitosan became soluble in acid-free water completely, and its solubility was 8.02mg/mL. Copyright © 2017 Elsevier B.V. All rights reserved.

Light-cone gauge approach to arbitrary spin fields, currents and shadows

International Nuclear Information System (INIS)

Metsaev, R R

2014-01-01

Totally symmetric arbitrary spin fields in AdS space, conformal fields, conformal currents, and shadow fields in flat space are studied. Light-cone gauge formulations for such fields, currents and shadows are obtained. Use of the Poincaré parametrization of AdS space and ladder operators allows us to treat fields in flat and AdS spaces on an equal footing. Light-cone gauge realization of relativistic symmetries for fields, currents and shadows is also obtained. The light-cone gauge formulation for fields is obtained by using the gauge invariant Lagrangian which is presented in terms of modified de Donder divergence, while the light-cone gauge formulation for currents and shadows is obtained by using the gauge invariant approach to currents and shadows. This allows us to demonstrate explicitly how the ladder operators entering the gauge invariant formulation of fields, currents and shadows manifest themselves in the light-cone gauge formulation for fields, currents and shadows. (paper)

Arachidonic acid-mediated inhibition of a potassium current in the giant neurons of Aplysia

International Nuclear Information System (INIS)

Carlson, R.O.

1990-01-01

Biochemical and electrophysiological approaches were used to investigate the role of arachidonic acid (AA) in the modulation of an inwardly rectifying potassium current (I R ) in the giant neurons of the marine snail, Aplysia californica. Using [ 3 H]AA as tracer, the intracellular free AA pool in Aplysia ganglia was found to be in a state of constant and rapid turnover through deacylation and reacylation of phospholipid, primarily phosphatidyl-inositol. This constant turnover was accompanied by a constant release of free AA and eicosanoids into the extracellular medium. The effects of three pharmacological agents were characterized with regard to AA metabolism in Aplysia ganglia. 4-O-tetra-decanoylphorbol 13-acetate (TPA), an activator of protein kinase C, stimulated liberation of AA from phospholipid, and 4-bromophenacylbromide (BPB), an inhibitor of phospholipate A 2 , inhibited this liberation. Indomethacin at 250 μM was found to inhibit uptake of AA, likely through inhibition of acyl-CoA synthetase. These agents were also found to modulate I R in ways which were consistent with their biological effects: TPA inhibited I R , and both BPB and indomethacin stimulated I R . Modulation of I R by these substances was found not to involve cAMP metabolism. Acute application of exogenous AA did not affect I R ; however, I R in giant neurons was found to be inhibited after dialysis with AA or other unsaturated fatty acids. Also, after perfusion with BSA overnight, a treatment which strips the giant neurons of AA in lipid storage, I R was found to have increased over 2-fold. This perfusion-induced increase was inhibited by the presence of AA or by pretreatment of the giant neurons with BPB. These results suggest AA, provided through constant turnover from phospholipid, mediates constitutive inhibition of I R

Treatment of intracerebral haemorrhage with tranexamic acid – A review of current evidence and ongoing trials

DEFF Research Database (Denmark)

Law, Zhe Kang; Meretoja, Atte; Engelter, Stefan T

2017-01-01

Purpose Haematoma expansion is a devastating complication of intracerebral haemorrhage (ICH) with no established treatment. Tranexamic acid had been an effective haemostatic agent in reducing post-operative and traumatic bleeding. We review current evidence examining the efficacy of tranexamic acid...... in improving clinical outcome after ICH. Method We searched MEDLINE, EMBASE, CENTRAL and clinical trial registers for studies using search strategies incorporating the terms ‘intracerebral haemorrhage’, ‘tranexamic acid’ and ‘antifibrinolytic’. Authors of ongoing clinical trials were contacted for further...... details. Findings We screened 268 publications and retrieved 17 articles after screening. Unpublished information from three ongoing clinical trials was obtained. We found five completed studies. Of these, two randomised controlled trials (RCTs) comparing intravenous tranexamic acid to placebo (n = 54...

Glycolic acid peel therapy – a current review

Directory of Open Access Journals (Sweden)

Sharad J

2013-11-01

Full Text Available Jaishree Sharad Skinfiniti Aesthetic Skin and Laser Clinic, Mumbai, India Abstract: Chemical peels have been time-tested and are here to stay. Alpha-hydroxy peels are highly popular in the dermatologist's arsenal of procedures. Glycolic acid peel is the most common alpha-hydroxy acid peel, also known as fruit peel. It is simple, inexpensive, and has no downtime. This review talks about various studies of glycolic acid peels for various indications, such as acne, acne scars, melasma, postinflammatory hyperpigmentation, photoaging, and seborrhea. Combination therapies and treatment procedure are also discussed. Careful review of medical history, examination of the skin, and pre-peel priming of skin are important before every peel. Proper patient selection, peel timing, and neutralization on-time will ensure good results, with no side effects. Depth of the glycolic acid peel depends on the concentration of the acid used, the number of coats applied, and the time for which it is applied. Hence, it can be used as a very superficial peel, or even a medium depth peel. It has been found to be very safe with Fitzpatrick skin types I–IV. All in all, it is a peel that is here to stay. Keywords: acne scar, melasma, photoaging, chemical peel, alpha-hydroxy peel

Quantum dot as a spin-current diode: A master-equation approach

DEFF Research Database (Denmark)

Souza, F.M.; Egues, J.C.; Jauho, Antti-Pekka

2007-01-01

We report a study of spin-dependent transport in a system composed of a quantum dot coupled to a normal metal lead and a ferromagnetic lead NM-QD-FM. We use the master equation approach to calculate the spin-resolved currents in the presence of an external bias and an intradot Coulomb interaction....... We find that for a range of positive external biases current flow from the normal metal to the ferromagnet the current polarization =I↑−I↓ / I↑+I↓ is suppressed to zero, while for the corresponding negative biases current flow from the ferromagnet to the normal metal attains a relative maximum value....... The system thus operates as a rectifier for spin-current polarization. This effect follows from an interplay between Coulomb interaction and nonequilibrium spin accumulation in the dot. In the parameter range considered, we also show that the above results can be obtained via nonequilibrium Green functions...

A progressive approach to discrete trial teaching: Some current guidelines

Directory of Open Access Journals (Sweden)

Justin B. Leaf

2016-12-01

Full Text Available Discrete trial teaching (DTT is one of the cornerstones of applied behavior analysis (ABA based interventions. Conventionally, DTT is commonly implemented within a prescribed, fixed manner in which the therapist is governed by a strict set of rules. In contrast to conventional DTT, a progressive approach to DTT allows the therapist to remain flexible, making in-the-moment analyses and changes based on several variables (e.g., individual responding, current and previous history. The present paper will describe some guidelines to a progressive approach to DTT. The guidelines presented here should not be taken as a set of rules or as an exhaustive list.

A Progressive Approach to Discrete Trial Teaching: Some Current Guidelines

Directory of Open Access Journals (Sweden)

Justin B. LEAF

2016-12-01

Full Text Available Discrete trial teaching (DTT is one of the cornerstones of applied behavior analysis (ABA based interventions. Conventionally, DTT is commonly implemented within a prescribed, fixed manner in which the therapist is governed by a strict set of rules. In contrast to conventional DTT, a progressive approach to DTT allows the therapist to remain flexible, making in-the-moment analyses and changes based on several variables (e.g., individual responding, current and previous history. The present paper will describe some guidelines to a progressive approach to DTT. The guidelines presented here should not be taken as a set of rules or as an exhaustive list.

Skills Training for School Leavers: Some Alternative Approaches. Current Issues Brief No. 2.

Science.gov (United States)

Fraser, Doug

In the face of escalating youth unemployment, some new approaches are needed for training out-of-school youth in Australia. The current system of apprenticeship has become outmoded because many of the skilled trades that the system prepares young people for will soon be non-existent. One approach to this problem has been implementation of…

Breast cancer treatment: historical review and current approaches

International Nuclear Information System (INIS)

Kulakowski, A.

1994-01-01

The evolution and development of opinions on the diagnosis and treatment of breast cancer since Galen to present time is presented. The concept of breast cancer as a local disease has been replaced by the understanding of its systemic character. On this background described are the methods of surgical treatment beginning from early - supraradical, to present -conservative approaches. The ''milestones'' in diagnosis and treatment of breast cancer of the last 40 years are presented. Current methods of breast cancer management include correct diagnosis (clinical examination, mammography, ultrasound, fine needle aspiration biopsy), TNM staging, adequate loco-regional therapy, systemic therapy, rehabilitation, reconstruction and careful follow-up. (author)

Electrolyte and Acid-Base Disturbances in End-Stage Liver Disease: A Physiopathological Approach.

Science.gov (United States)

Jiménez, José Víctor; Carrillo-Pérez, Diego Luis; Rosado-Canto, Rodrigo; García-Juárez, Ignacio; Torre, Aldo; Kershenobich, David; Carrillo-Maravilla, Eduardo

2017-08-01

Electrolyte and acid-base disturbances are frequent in patients with end-stage liver disease; the underlying physiopathological mechanisms are often complex and represent a diagnostic and therapeutic challenge to the physician. Usually, these disorders do not develop in compensated cirrhotic patients, but with the onset of the classic complications of cirrhosis such as ascites, renal failure, spontaneous bacterial peritonitis and variceal bleeding, multiple electrolyte, and acid-base disturbances emerge. Hyponatremia parallels ascites formation and is a well-known trigger of hepatic encephalopathy; its management in this particular population poses a risky challenge due to the high susceptibility of cirrhotic patients to osmotic demyelination. Hypokalemia is common in the setting of cirrhosis: multiple potassium wasting mechanisms both inherent to the disease and resulting from its management make these patients particularly susceptible to potassium depletion even in the setting of normokalemia. Acid-base disturbances range from classical respiratory alkalosis to high anion gap metabolic acidosis, almost comprising the full acid-base spectrum. Because most electrolyte and acid-base disturbances are managed in terms of their underlying trigger factors, a systematic physiopathological approach to their diagnosis and treatment is required.

VALUE-BASED APPROACH TO MANAGING CURRENT ASSETS OF CORPORATE CONSTRUCTION COMPANIES

Directory of Open Access Journals (Sweden)

Galyna Shapoval

2017-09-01

Full Text Available In modern conditions of management, the value of an enterprise becomes the main indicator, which is learned not only by scientists, but also by owners of enterprise and potential investors. Current assets take a very important place among the factors that affect the value of an enterprise, so management of current assets becomes more acute from the point of their impact on enterprise value. The purpose of the paper is to develop a system of value-based management of corporate construction companies’ current assets. The main tasks are: the study of current assets impact on the value of corporate construction companies, the definition of value-based approach to managing current assets of corporate enterprises and development of value-based management system of corporate construction companies’ current assets by elements. General scientific and special research methods were used while writing the work. Value-based management of current assets involves value-based management of the elements of current assets. The value-based inventory management includes the following stages of management: the assessment of reliability and choice of supplier according to the criterion of cash flow maximization, the classification of stocks in management accounting according to the rhythm of supply and the establishment of periodicity of supplies in accordance with the needs of the construction process. The value-based management of accounts receivable includes the following stages of management: assessment of the efficiency of investment of working capital into accounts receivable, the assessment of customers' loyalty and the definition of credit conditions and monitoring of receivables by construction and debt instruments. Value-based cash management involves determining the required level of cash to ensure the continuity of the construction process, assessing the effectiveness of cash use according to the criterion of maximizing cash flow, as well as budget

Counter-current acid leaching process for the removal of Cu, Pb, Sb and Zn from shooting range soil.

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Lafond, Stéphanie; Blais, Jean-François; Mercier, Guy; Martel, Richard

2013-01-01

This research explores the performance of a counter-current leaching process (CCLP) for Cu, Pb, Sb and Zn extraction in a polluted shooting range soil. The initial metal concentrations in the soil were 1790 mg Cu/kg, 48,300 mg Pb/kg, 840 mg Sb/kg and 368 mg Zn/kg. The leaching process consisted of five one-hour acid leaching steps, which used 1 M H2SO4 + 4 M NaCl (20 degrees C, soil suspension = 100 g/L) followed by two water rinsing steps. Ten counter-current remediation cycles were completed and the average metal removal yields were 98.3 +/- 0.3% of Cu, 99.5 +/- 0.1% of Pb, 75.5 +/- 5.1% of Sb and 29.1 +/- 27.2% of Zn. The quality of metal leaching did not deteriorate throughout the 10 remediation cycles completed for this study. The CCLP reduced acid and salt use by approximately 68% and reduced water consumption by approximately 60%, exceeding reductions achieved by a standard acid leaching process.

A broad-spectrum, efficient and nontransgenic approach to control plant viruses by application of salicylic acid and jasmonic acid.

Science.gov (United States)

Shang, Jing; Xi, De-Hui; Xu, Fei; Wang, Shao-Dong; Cao, Sen; Xu, Mo-Yun; Zhao, Ping-Ping; Wang, Jian-Hui; Jia, Shu-Dan; Zhang, Zhong-Wei; Yuan, Shu; Lin, Hong-Hui

2011-02-01

Plant viruses cause many diseases that lead to significant economic losses. However, most of the approaches to control plant viruses, including transgenic processes or drugs are plant-species-limited or virus-species-limited, and not very effective. We introduce an application of jasmonic acid (JA) and salicylic acid (SA), a broad-spectrum, efficient and nontransgenic method, to improve plant resistance to RNA viruses. Applying 0.06 mM JA and then 0.1 mM SA 24 h later, enhanced resistance to Cucumber mosaic virus (CMV), Tobacco mosaic virus (TMV) and Turnip crinkle virus (TCV) in Arabidopsis, tobacco, tomato and hot pepper. The inhibition efficiency to virus replication usually achieved up to 80-90%. The putative molecular mechanism was investigated. Some possible factors affecting the synergism of JA and SA have been defined, including WRKY53, WRKY70, PDF1.2, MPK4, MPK2, MPK3, MPK5, MPK12, MPK14, MKK1, MKK2, and MKK6. All genes involving in the synergism of JA and SA were investigated. This approach is safe to human beings and environmentally friendly and shows potential as a strong tool for crop protection against plant viruses.

Environmental release of living modified organisms: current approaches and case studies.

Science.gov (United States)

Thomas, E; Nickson, Ph D

2005-01-01

Agricultural biotechnology is being rapidly adopted as evidenced by the acreage of genetically modified (GM) crops planted and tonnes of product (grain and fiber) harvested. Concurrent with this technological progress, is a growing concern that the worlds biological diversity is coming under increasing threat from human activities. As such, ecological risk assessment approaches are being developed for GM crop plants as international agreements regulating the transboundary movements of these products are being implemented. This paper reviews the ecological risk assessment approach that has been used to date to approve GM crops to date. The process has been case-by-case, using a comparative, science-based approach balancing the potential risks and benefits of the new technology versus those present with the currently accepted practices. The approach used to evaluate and approve these products is consistent with the conditions and requirements outlined in the Cartagena Protocol.

A novel HPLC-ESI-Q-ToF approach for the determination of fatty acids and acylglycerols in food samples.

Science.gov (United States)

La Nasa, Jacopo; Degano, Ilaria; Brandolini, Leonardo; Modugno, Francesca; Bonaduce, Ilaria

2018-07-12

We propose a new analytical method using reverse phase High performance liquid chromatography (HPLC) coupled through an electrospray source with a tandem quadrupole-time-of-flight (ESI-Q-ToF) mass spectrometric detector for the full characterization and quantitation of the different classes of fatty acids and acylglycerols in lipid samples in a single chromatographic run. In this work, we optimized the derivatization reaction for free fatty acids with 2-hydrazinoquinoline, which is a low-cost approach, using a full factorial design. This reaction does not involve transesterification, thus enabling the free fatty acids to be separated and successfully quantified in the presence of mono-, di- and triacylglycerols without altering the whole glyceride profile. This new analytical method provides a full profile of fatty acids, mono-, di- and triglycerides within a relatively short chromatographic run (less than 40 min), with low operating back-pressure (less than 110 bar). The derivatization of the free fatty acids allows their detection in positive mode, with limits of detection in the range of 0.2-1.9 ng/g, and a dynamic range of two orders of magnitude. The figures of merit of the procedure are competitive with respect to the literature. The method was validated by characterizing two different types of olive oils. Free fatty acid content was quantified, and the results are consistent with literature data. The method was applied to the characterization of cow milk and an infant formula, after the precipitation of proteins and phospholipids, and proved suitable for the detection of short chain fatty acids, free fatty acids and glycerides highlighting differences in the composition of the two milks. The proposed procedure improves the current methods for the analysis of acylglyceride based materials, such as olive oil, and proved promising for the characterization of lipids in complex matrices, such as milk. Copyright © 2018 Elsevier B.V. All rights reserved.

Therapeutic Mechanisms of Bile Acids and Nor-Ursodeoxycholic Acid in Non-Alcoholic Fatty Liver Disease.

Science.gov (United States)

Steinacher, Daniel; Claudel, Thierry; Trauner, Michael

2017-01-01

Non-alcoholic fatty liver disease is one of the most rapidly rising clinical problems in the 21st century. So far no effective drug treatment has been established to cure this disease. Bile acids (BAs) have a variety of signaling properties, which can be used therapeutically for modulating hepatic metabolism and inflammation. A side-chain shorted derivative of ursodeoxycholic acid (UDCA) is 24 nor-ursodeoxycholic acid (NorUDCA) and it represents a new class of drugs for treatment of liver diseases. NorUDCA has unique biochemical and therapeutic properties, since it is relatively resistant to conjugation with glycine or taurine compared to UDCA. NorUDCA undergoes cholehepatic shunting, resulting in ductular targeting, bicarbonate-rich hypercholeresis, and cholangiocyte protection. Furthermore, it showed anti-fibrotic, anti-inflammatory, and anti-lipotoxic properties in several animal models. As such, NorUDCA is a promising new approach in the treatment of cholestatic and metabolic liver diseases. This review is a summary of current BA-based therapeutic approaches in the treatment of the fatty liver disease. © 2017 S. Karger AG, Basel.

Two complementary approaches to right-handed currents

International Nuclear Information System (INIS)

Gemmler, Katrin M.

2012-01-01

Flavour observables impose strong constraints on models of new physics. We study whether right-handed currents can provide a realistic extension to the Standard Model. We analyse two complementary models. These setups lead to new flavour violating interactions in the right-handed sector. We first consider a bottom-up approach assuming a left-right symmetric flavour group broken only by the Yukawa couplings. In this model the vertical stroke V ub vertical stroke problem can be solved. Secondly we study the Left-Right Model. We perform a comprehensive numerical analysis, including all known experimental constraints from ΔF=2 observables and the decay B →X s γ simultaneously. We observe that there exist regions in parameter space in accordance with the all data. In this model all flavour anomalies can be resolved except the vertical stroke V ub vertical stroke problem.

Optimizing nitrogen fertilizer use: Current approaches and simulation models

International Nuclear Information System (INIS)

Baethgen, W.E.

2000-01-01

Nitrogen (N) is the most common limiting nutrient in agricultural systems throughout the world. Crops need sufficient available N to achieve optimum yields and adequate grain-protein content. Consequently, sub-optimal rates of N fertilizers typically cause lower economical benefits for farmers. On the other hand, excessive N fertilizer use may result in environmental problems such as nitrate contamination of groundwater and emission of N 2 O and NO. In spite of the economical and environmental importance of good N fertilizer management, the development of optimum fertilizer recommendations is still a major challenge in most agricultural systems. This article reviews the approaches most commonly used for making N recommendations: expected yield level, soil testing and plant analysis (including quick tests). The paper introduces the application of simulation models that complement traditional approaches, and includes some examples of current applications in Africa and South America. (author)

Metabolic Interaction between Urea Cycle and Citric Acid Cycle Shunt: A Guided Approach

Science.gov (United States)

Pesi, Rossana; Balestri, Francesco; Ipata, Piero L.

2018-01-01

This article is a guided pedagogical approach, devoted to postgraduate students specializing in biochemistry, aimed at presenting all single reactions and overall equations leading to the metabolic interaction between ureagenesis and citric acid cycle to be incorporated into a two-three lecture series about the interaction of urea cycle with other…

Gene Therapy for Advanced Melanoma: Selective Targeting and Therapeutic Nucleic Acids

Directory of Open Access Journals (Sweden)

Joana R. Viola

2013-01-01

Full Text Available Despite recent advances, the treatment of malignant melanoma still results in the relapse of the disease, and second line treatment mostly fails due to the occurrence of resistance. A wide range of mutations are known to prevent effective treatment with chemotherapeutic drugs. Hence, approaches with biopharmaceuticals including proteins, like antibodies or cytokines, are applied. As an alternative, regimens with therapeutically active nucleic acids offer the possibility for highly selective cancer treatment whilst avoiding unwanted and toxic side effects. This paper gives a brief introduction into the mechanism of this devastating disease, discusses the shortcoming of current therapy approaches, and pinpoints anchor points which could be harnessed for therapeutic intervention with nucleic acids. We bring the delivery of nucleic acid nanopharmaceutics into perspective as a novel antimelanoma therapeutic approach and discuss the possibilities for melanoma specific targeting. The latest reports on preclinical and already clinical application of nucleic acids in melanoma are discussed.

Low-energy hadronic interactions beyond the current algebra approach

International Nuclear Information System (INIS)

Ivanov, A.N.; Troitskaya, N.I.; Nagy, M.

1993-06-01

The new low-energy AP 3 -interaction, which is produced by convergent box-constituent-quark-loop diagrams, is obtained within chiral perturbation theory at the quark level (CHPT) q with linear realization of chiral U(3) x U(3) symmetry. Its contributions to processes of low-energy interactions of low-lying mesons are investigated. The new interaction goes beyond the framework of the low-energy current algebra approach and of the effective chiral Lagrangians with linear realization of chiral symmetry, constructed at the hadronic level. (author). 17 refs, 3 figs

Current status of acid fog research. Sanseimu kenkyu no genjo

Energy Technology Data Exchange (ETDEWEB)

Murano, K. (National Inst. for Environmental Studies, Tsukuba (Japan))

1993-07-10

Acid fog research was behind in comparison with acid rain research. In case of acid fog, it is because the place generating sufficiently thick fog to collect is limited, the generating place is mountainous, its survey needs a lot of works, its collector is not convenient like in acid rain, or its sampling is difficult on its automation. Since the 1980s, an extensive survey on acid fog had been carried out centering the west coast of California, USA, and low pH fog (minimum pH 2.2) was observed. In the course of these researches, string type active fogwater collectors became a major sampling method, and the simulation of acidification of fog droplet in the atmosphere was extensively conducted. In Japan, already in the 1960s, field surveys on acid fog were conducted, in 1984 acid fog survey started on Mt. Akagi under a viewpoint of ecological impact, and there was a report that low pH fog (pH 3 to 4) continued more than 10 hours. It was pointed out that there were plant damage by acid fog in several locations, especially the tree mortality mechanism in Tomakomai was clarified. 50 refs., 10 figs., 6 tabs.

A Unified Current Loop Tuning Approach for Grid-Connected Photovoltaic Inverters

Directory of Open Access Journals (Sweden)

Weiyi Zhang

2016-09-01

Full Text Available High level penetration of renewable energy sources has reshaped modern electrical grids. For the future grid, distributed renewable power generation plants can be integrated in a larger scale. Control of grid-connected converters is required to achieve fast power reference tracking and further to present grid-supporting and fault ride-through performance. Among all of the aspects for converter control, the inner current loop for grid-connected converters characterizes the system performance considerably. This paper proposes a unified current loop tuning approach for grid-connected converters that is generally applicable in different cases. A direct discrete-time domain tuning procedure is used, and particularly, the selection of the phase margin and crossover frequency is analyzed, which acts as the main difference compared with the existing studies. As a general method, the approximation in the modeling of the controller and grid filter is avoided. The effectiveness of the tuning approach is validated in both simulation and experimental results with respect to power reference tracking, frequency and voltage supporting.

Nucleic acid drugs: a novel approach

African Journals Online (AJOL)

Administrator

Nucleic acid base sequence of proteins plays a crucial role in the expression of gene. The gene is responsible for the synthesis of proteins and these proteins, which are synthesized, are responsible for the biological process and also for dreadful diseases as well. Once if the nucleic acid sequence is altered, we would be ...

Computational approaches to analogical reasoning current trends

CERN Document Server

Richard, Gilles

2014-01-01

Analogical reasoning is known as a powerful mode for drawing plausible conclusions and solving problems. It has been the topic of a huge number of works by philosophers, anthropologists, linguists, psychologists, and computer scientists. As such, it has been early studied in artificial intelligence, with a particular renewal of interest in the last decade. The present volume provides a structured view of current research trends on computational approaches to analogical reasoning. It starts with an overview of the field, with an extensive bibliography. The 14 collected contributions cover a large scope of issues. First, the use of analogical proportions and analogies is explained and discussed in various natural language processing problems, as well as in automated deduction. Then, different formal frameworks for handling analogies are presented, dealing with case-based reasoning, heuristic-driven theory projection, commonsense reasoning about incomplete rule bases, logical proportions induced by similarity an...

Two complementary approaches to right-handed currents

Energy Technology Data Exchange (ETDEWEB)

Gemmler, Katrin M.

2012-04-17

Flavour observables impose strong constraints on models of new physics. We study whether right-handed currents can provide a realistic extension to the Standard Model. We analyse two complementary models. These setups lead to new flavour violating interactions in the right-handed sector. We first consider a bottom-up approach assuming a left-right symmetric flavour group broken only by the Yukawa couplings. In this model the vertical stroke V{sub ub} vertical stroke problem can be solved. Secondly we study the Left-Right Model. We perform a comprehensive numerical analysis, including all known experimental constraints from {Delta}F=2 observables and the decay B {yields}X{sub s}{gamma} simultaneously. We observe that there exist regions in parameter space in accordance with the all data. In this model all flavour anomalies can be resolved except the vertical stroke V{sub ub} vertical stroke problem.

Respiratory sensitization and allergy: Current research approaches and needs

International Nuclear Information System (INIS)

Boverhof, Darrell R.; Billington, Richard; Gollapudi, B. Bhaskar; Hotchkiss, John A.; Krieger, Shannon M.; Poole, Alan; Wiescinski, Connie M.; Woolhiser, Michael R.

2008-01-01

There are currently no accepted regulatory models for assessing the potential of a substance to cause respiratory sensitization and allergy. In contrast, a number of models exist for the assessment of contact sensitization and allergic contact dermatitis (ACD). Research indicates that respiratory sensitizers may be identified through contact sensitization assays such as the local lymph node assay, although only a small subset of the compounds that yield positive results in these assays are actually respiratory sensitizers. Due to the increasing health concerns associated with occupational asthma and the impending directives on the regulation of respiratory sensitizers and allergens, an approach which can identify these compounds and distinguish them from contact sensitizers is required. This report discusses some of the important contrasts between respiratory allergy and ACD, and highlights several prominent in vivo, in vitro and in silico approaches that are being applied or could be further developed to identify compounds capable of causing respiratory allergy. Although a number of animal models have been used for researching respiratory sensitization and allergy, protocols and endpoints for these approaches are often inconsistent, costly and difficult to reproduce, thereby limiting meaningful comparisons of data between laboratories and development of a consensus approach. A number of emerging in vitro and in silico models show promise for use in the characterization of contact sensitization potential and should be further explored for their ability to identify and differentiate contact and respiratory sensitizers. Ultimately, the development of a consistent, accurate and cost-effective model will likely incorporate a number of these approaches and will require effective communication, collaboration and consensus among all stakeholders

The Current Role of Omega-3 Fatty Acids in the Management of Atrial Fibrillation.

Science.gov (United States)

Christou, Georgios A; Christou, Konstantinos A; Korantzopoulos, Panagiotis; Rizos, Evangelos C; Nikas, Dimitrios N; Goudevenos, John A

2015-09-22

The main dietary source of omega-3 polyunsaturated fatty acids (n-3 PUFA) is fish, which contains eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In the present manuscript, we aimed to review the current evidence regarding the clinical role of n-3 PUFA in the prevention of atrial fibrillation (AF) and the possible underlying mechanisms. A literature search based on PubMed listings was performed using "Omega-3 fatty acids" and "atrial fibrilation" as key search terms. n-3 PUFA have been shown to attenuate structural atrial remodeling, prolong atrial effective refractory period through the prevention of reentry and suppress ectopic firing from pulmonary veins. Dietary fish intake has been found to have no effect on the incidence of AF in the majority of studies. Circulating DHA has been consistently reported to be inversely associated with AF risk, whereas EPA has no such effect. The majority of studies investigating the impact of n-3 PUFA supplementation on the incidence of AF following cardiac surgery reported no benefit, though most of them did not use n-3 PUFA pretreatment for adequate duration. Studies using adequate four-week pretreatment with n-3 PUFA before cardioversion of AF showed a reduction of the AF incidence. Although n-3 PUFA have antiarrhythmogenic properties, their clinical efficacy on the prevention of AF is not consistently supported. Further well-designed studies are needed to overcome the limitations of the existing studies and provide robust conclusions.

Investigating students' view on STEM in learning about electrical current through STS approach

Science.gov (United States)

Tupsai, Jiraporn; Yuenyong, Chokchai

2018-01-01

This study aims to investigate Grade 11 students' views on Science Technology Engineering Mathematics (STEM) with the integration of learning about electrical current based on Science Technology Society (STS) approach [8]. The participants were 60 Grade 11 students in Demonstration Secondary School, Khon Kaen University, Khon Kaen Province, Thailand. The methodology is in the respect of interpretive paradigm. The teaching and learning about Electrical Current through STS approach carried out over 6 weeks. The Electrical Current unit through STS approach was developed based on framework[8] that consists of five stages including (1) identification of social issues, (2) identification of potential solutions, (3) need for knowledge, (4) decision making, and (5) socialization stage. To start with, the question "what if this world is lack of electricity" was challenged in the class in order to move students to find the problem of how to design Electricity Generation from Clean Energy. Students were expected to apply scientific and other knowledge to design of Electricity Generation. Students' views on STEM were collected during their learning by participant' observation and students' tasks. Their views on STEM were categorized when they applied their knowledge for designing the Electricity Generation. The findings indicated that students cooperatively work to solve the problem when applying knowledge about the content of Science and Mathematics and processing skill of Technology and Engineering. It showed that students held the integration of science, technology, engineering and mathematics to design their possible solutions in learning about Electrical Current. The paper also discusses implications for science teaching and learning through STS in Thailand.

In-stream chemical neutralization: A whole watershed approach to mitigating acid mine drainage

International Nuclear Information System (INIS)

Britt, D.L.

1994-01-01

The North Branch of the Potomac River is adversely affected by acid mine drainage (AMD) throughout its entire length. As an alternative to mine-mouth treatment methods an in-stream AMD-neutralization demonstration program for an approximately 25-mile segment of the North Branch of the Potomac River was designed and implemented. This river segment was ranked as the highest priority site in Maryland for a demonstration project owing to its combination of very poor water quality and excellent potential for supporting a recreational sport fishery in the absence of toxic metal and acid loadings. A whole-watershed approach employing Scandinavian doser technologies and calcium carbonate neutralizing agents is the basis for the North Branch Potomac River demonstration project. The project involves four phases: feasibility (1), design (2), implementation (3), and monitoring (4). This watershed approach to mitigating AMD is expected to restore circumneutrial water quality and to promote desirable fishery resources throughout the mainstem and selected tributaries of the North Branch of the Potomac River Upstream of Jennings Randolph Dam. This paper summarizes Phases 1--3 of the demonstration project

A new approach to study cadmium complexes with oxalic acid in soil solution.

Science.gov (United States)

Dytrtová, Jana Jaklová; Jakl, Michal; Sestáková, Ivana; Zins, Emilie-Laure; Schröder, Detlef; Navrátil, Tomáš

2011-05-05

This study presents a new analytical approach for the determination of heavy metals complexed to low-molecular-weight-organic acids in soil solutions, which combines the sensitivity of differential pulse anodic stripping voltammetry (DPASV) with the molecular insight gained by electrospray ionization mass spectrometry (ESI-MS). The combination of these analytical methods allows the investigation of such complexes in complex matrixes. On the voltammograms of the soil solutions, in addition to the expected complexes of oxalic acid with cadmium and lead, respectively, also peaks belonging to mixed complexes of cadmium, lead, and oxalic acid (OAH(2)) were observed. In order to verify the possible formation of complexes with OAH(2), aqueous solutions of OAH(2) with traces of Cd(II) were investigated as model systems. Signals corresponding to several distinct molecular complexes between cadmium and oxalic acid were detected in the model solutions using negative-ion ESI-MS, which follow the general formula [Cd(n)(X,Y)((2n+1))](-), where n is the number of cadmium atoms, X=Cl(-), and Y=OAH(-). Some of these complexes were also identified in the ESI mass spectra taken from the soil solutions. Copyright © 2011 Elsevier B.V. All rights reserved.

A new approach to study cadmium complexes with oxalic acid in soil solution

International Nuclear Information System (INIS)

Jaklova Dytrtova, Jana; Jakl, Michal; Sestakova, Ivana; Zins, Emilie-Laure; Schroeder, Detlef; Navratil, Tomas

2011-01-01

This study presents a new analytical approach for the determination of heavy metals complexed to low-molecular-weight-organic acids in soil solutions, which combines the sensitivity of differential pulse anodic stripping voltammetry (DPASV) with the molecular insight gained by electrospray ionization mass spectrometry (ESI-MS). The combination of these analytical methods allows the investigation of such complexes in complex matrixes. On the voltammograms of the soil solutions, in addition to the expected complexes of oxalic acid with cadmium and lead, respectively, also peaks belonging to mixed complexes of cadmium, lead, and oxalic acid (OAH 2 ) were observed. In order to verify the possible formation of complexes with OAH 2 , aqueous solutions of OAH 2 with traces of Cd(II) were investigated as model systems. Signals corresponding to several distinct molecular complexes between cadmium and oxalic acid were detected in the model solutions using negative-ion ESI-MS, which follow the general formula [Cd n (X,Y) (2n+1) ] - , where n is the number of cadmium atoms, X = Cl - , and Y = OAH - . Some of these complexes were also identified in the ESI mass spectra taken from the soil solutions.

A new approach to study cadmium complexes with oxalic acid in soil solution

Energy Technology Data Exchange (ETDEWEB)

Jaklova Dytrtova, Jana, E-mail: dytrtova@uochb.cas.cz [Institute of Organic Chemistry and Biochemistry of the AS CR, v.v.i., Flemingovo namesti 2, 16610 Prague 6 (Czech Republic); Jakl, Michal [Department of Agro-Environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamycka 129, 16521 Prague - Suchdol (Czech Republic); Sestakova, Ivana [J. Heyrovsky Institute of Physical Chemistry of the AS CR, v.v.i., Dolejskova 3, 182 23 Prague 8 (Czech Republic); Zins, Emilie-Laure; Schroeder, Detlef [Institute of Organic Chemistry and Biochemistry of the AS CR, v.v.i., Flemingovo namesti 2, 16610 Prague 6 (Czech Republic); Navratil, Tomas [J. Heyrovsky Institute of Physical Chemistry of the AS CR, v.v.i., Dolejskova 3, 182 23 Prague 8 (Czech Republic)

2011-05-05

This study presents a new analytical approach for the determination of heavy metals complexed to low-molecular-weight-organic acids in soil solutions, which combines the sensitivity of differential pulse anodic stripping voltammetry (DPASV) with the molecular insight gained by electrospray ionization mass spectrometry (ESI-MS). The combination of these analytical methods allows the investigation of such complexes in complex matrixes. On the voltammograms of the soil solutions, in addition to the expected complexes of oxalic acid with cadmium and lead, respectively, also peaks belonging to mixed complexes of cadmium, lead, and oxalic acid (OAH{sub 2}) were observed. In order to verify the possible formation of complexes with OAH{sub 2}, aqueous solutions of OAH{sub 2} with traces of Cd(II) were investigated as model systems. Signals corresponding to several distinct molecular complexes between cadmium and oxalic acid were detected in the model solutions using negative-ion ESI-MS, which follow the general formula [Cd{sub n}(X,Y){sub (2n+1)}]{sup -}, where n is the number of cadmium atoms, X = Cl{sup -}, and Y = OAH{sup -}. Some of these complexes were also identified in the ESI mass spectra taken from the soil solutions.

Carbon and nitrogen isotopes from top predator amino acids reveal rapidly shifting ocean biochemistry in the outer California Current.

Directory of Open Access Journals (Sweden)

Rocio I Ruiz-Cooley

Full Text Available Climatic variation alters biochemical and ecological processes, but it is difficult both to quantify the magnitude of such changes, and to differentiate long-term shifts from inter-annual variability. Here, we simultaneously quantify decade-scale isotopic variability at the lowest and highest trophic positions in the offshore California Current System (CCS by measuring δ15N and δ13C values of amino acids in a top predator, the sperm whale (Physeter macrocephalus. Using a time series of skin tissue samples as a biological archive, isotopic records from individual amino acids (AAs can reveal the proximate factors driving a temporal decline we observed in bulk isotope values (a decline of ≥1 ‰ by decoupling changes in primary producer isotope values from those linked to the trophic position of this toothed whale. A continuous decline in baseline (i.e., primary producer δ15N and δ13C values was observed from 1993 to 2005 (a decrease of ∼4‰ for δ15N source-AAs and 3‰ for δ13C essential-AAs, while the trophic position of whales was variable over time and it did not exhibit directional trends. The baseline δ15N and δ13C shifts suggest rapid ongoing changes in the carbon and nitrogen biogeochemical cycling in the offshore CCS, potentially occurring at faster rates than long-term shifts observed elsewhere in the Pacific. While the mechanisms forcing these biogeochemical shifts remain to be determined, our data suggest possible links to natural climate variability, and also corresponding shifts in surface nutrient availability. Our study demonstrates that isotopic analysis of individual amino acids from a top marine mammal predator can be a powerful new approach to reconstructing temporal variation in both biochemical cycling and trophic structure.

Carbon and nitrogen isotopes from top predator amino acids reveal rapidly shifting ocean biochemistry in the outer California Current.

Science.gov (United States)

Ruiz-Cooley, Rocio I; Koch, Paul L; Fiedler, Paul C; McCarthy, Matthew D

2014-01-01

Climatic variation alters biochemical and ecological processes, but it is difficult both to quantify the magnitude of such changes, and to differentiate long-term shifts from inter-annual variability. Here, we simultaneously quantify decade-scale isotopic variability at the lowest and highest trophic positions in the offshore California Current System (CCS) by measuring δ15N and δ13C values of amino acids in a top predator, the sperm whale (Physeter macrocephalus). Using a time series of skin tissue samples as a biological archive, isotopic records from individual amino acids (AAs) can reveal the proximate factors driving a temporal decline we observed in bulk isotope values (a decline of ≥1 ‰) by decoupling changes in primary producer isotope values from those linked to the trophic position of this toothed whale. A continuous decline in baseline (i.e., primary producer) δ15N and δ13C values was observed from 1993 to 2005 (a decrease of ∼4‰ for δ15N source-AAs and 3‰ for δ13C essential-AAs), while the trophic position of whales was variable over time and it did not exhibit directional trends. The baseline δ15N and δ13C shifts suggest rapid ongoing changes in the carbon and nitrogen biogeochemical cycling in the offshore CCS, potentially occurring at faster rates than long-term shifts observed elsewhere in the Pacific. While the mechanisms forcing these biogeochemical shifts remain to be determined, our data suggest possible links to natural climate variability, and also corresponding shifts in surface nutrient availability. Our study demonstrates that isotopic analysis of individual amino acids from a top marine mammal predator can be a powerful new approach to reconstructing temporal variation in both biochemical cycling and trophic structure.

[Teichoic acids from lactic acid bacteria].

Science.gov (United States)

Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

2012-01-01

The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

State Higher Education Funding Models: An Assessment of Current and Emerging Approaches

Science.gov (United States)

Layzell, Daniel T.

2007-01-01

This article provides an assessment of the current and emerging approaches used by state governments in allocating funding for higher education institutions and programs. It reviews a number of desired characteristics or outcomes for state higher education funding models, including equity, adequacy, stability, and flexibility. Although there is…

Multiplexed microfluidic approach for nucleic acid enrichment

Science.gov (United States)

VanderNoot, Victoria A.; Langevin, Stanley Alan; Bent, Zachary; Renzi, Ronald F.; Ferko, Scott M.; Van De Vreugde, James L.; Lane, Todd; Patel, Kamlesh; Branda, Steven

2016-04-26

A system for enhancing a nucleic acid sample may include a one pump, a denaturing chamber; a microfluidic hydroxyapatite chromatography device configured for performing hydroxyapatite chromatography on the nucleic acid sample, a sample collector, and tubing connecting the pump with the denaturing chamber, the hydroxyapatite chromatography device and the sample collector such that the pump may be used to move the nucleic acid sample from the denaturing chamber to the hydroxyapatite chromatography device and then to the sample collector.

Nor-Ursodeoxycholic Acid as a Novel Therapeutic Approach for Cholestatic and Metabolic Liver Diseases.

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Halilbasic, Emina; Steinacher, Daniel; Trauner, Michael

2017-01-01

Norursodeoxycholic acid (norUDCA) is a side-chain-shortened derivative of ursodeoxycholic acid with relative resistance to amidation, which enables its cholehepatic shunting. Based on its specific pharmacologic properties, norUDCA is a promising drug for a range of cholestatic liver and bile duct disorders. Recently, norUDCA has been successfully tested clinically in patients with primary sclerosing cholangitis (PSC) as first application in patients. Moreover, hepatic enrichment of norUDCA facilitates direct therapeutic effects on both parenchymal and non-parenchymal liver cells, thereby counteracting cholestasis, steatosis, hepatic inflammation and fibrosis, inhibiting hepatocellular proliferation, and promoting autophagy. This may open its therapeutic use to other non-cholestatic and metabolic liver diseases. This review article is a summary of a lecture given at the XXIV International Bile Acid Meeting (Falk Symposium 203) on "Bile Acids in Health and Disease" held in Düsseldorf, on June 17-18, 2016 and summarizes the recent progress of norUDCA as novel therapeutic approach in cholestatic and metabolic liver disorders with a specific focus on PSC. © 2017 S. Karger AG, Basel.

Biodegradable Poly(D,L-lactic-co-glycolic acid)-Based Micro ...

African Journals Online (AJOL)

... drug encapsulation efficiency and release profile of PLGA mico/nanoparticles. The current knowledge of protein instability during preparation, storage and release from PLGA micro/nanoparticles and protein stabilization approaches has also been discussed in this review. Keywords: Poly(D, L-lactic-co-glycolic acid), ...

Determination of acid ionization constants for weak acids by osmometry and the instrumental analysis self-evaluation feedback approach to student preparation of solutions

Science.gov (United States)

Kakolesha, Nyanguila

One focus of this work was to develop of an alternative method to conductivity for determining the acid ionization constants. Computer-controlled osmometry is one of the emerging analytical tools in industrial research and clinical laboratories. It is slowly finding its way into chemistry laboratories. The instrument's microprocessor control ensures shortened data collection time, repeatability, accuracy, and automatic calibration. The equilibrium constants of acetic acid, chloroacetic acid, bromoacetic acid, cyanoacetic acid, and iodoacetic acid have been measured using osmometry and their values compared with the existing literature values obtained, usually, from conductometric measurements. Ionization constant determined by osmometry for the moderately strong weak acids were in reasonably good agreement with literature values. The results showed that two factors, the ionic strength and the osmotic coefficient, exert opposite effects in solutions of such weak acids. Another focus of the work was analytical chemistry students solution preparation skills. The prevailing teacher-structured experiments leave little room for students' ingenuity in quantitative volumetric analysis. The purpose of this part of the study was to improve students' skills in making solutions using instrument feedback in a constructivist-learning model. After making some solutions by weighing and dissolving solutes or by serial dilution, students used the spectrophotometer and the osmometer to compare their solutions with standard solutions. Students perceived the instrument feedback as a nonthreatening approach to monitoring the development of their skill levels and liked to clarify their understanding through interacting with an instructor-observer. An assessment of the instrument feedback and the constructivist model indicated that students would assume responsibility for their own learning if given the opportunity. This study involved 167 students enrolled in Quantitative Chemical

Conformational basis for the Li(+)-induced leak current in the rat gamma-aminobutyric acid (GABA) transporter-1

DEFF Research Database (Denmark)

MacAulay, Nanna; Zeuthen, Thomas; Gether, Ulrik

2002-01-01

The rat gamma-aminobutyric acid transporter-1 (GAT-1) was expressed in Xenopus laevis oocytes and the substrate-independent Li(+)-induced leak current was examined using two-electrode voltage clamp. The leak current was not affected by the addition of GABA and was not due to H(+) permeation. The Li......(+)-bound conformation of the protein displayed a lower passive water permeability than that of the Na(+)- and choline (Ch(+))-bound conformations and the leak current did not saturate with increasing amounts of Li(+) in the test solution. The mechanism that gives rise to the leak current did not support active water...... transport in contrast to the mechanism responsible for GABA translocation (approximately 330 water molecules per charge). Altogether, these data support the distinct nature of the leak conductance in relation to the substrate translocation process. It was observed that the leak current was inhibited by low...

The Role of GPR84 in Medium-chain Saturated Fatty Acid Taste Transduction

OpenAIRE

Liu, Yan

2016-01-01

Previous research has shown the gustatory recognition of the long-chain unsaturated fatty acids. In this study, I showed for the first time that medium-chain saturated fatty acids (MCFAs) are effective taste stimuli at both the cellular and behavioral levels. The mechanisms of gustatory recognition of MCFAs in mice were also partially elucidated using pharmaceutical approaches. The inward currents induced by capric acid in mouse taste cells were significantly inhibited by the antagonists of G...

Production of Fatty Acid-Derived Valuable Chemicals in Synthetic Microbes

International Nuclear Information System (INIS)

Yu, Ai-Qun; Pratomo Juwono, Nina Kurniasih; Leong, Susanna Su Jan; Chang, Matthew Wook

2014-01-01

Fatty acid derivatives, such as hydroxy fatty acids, fatty alcohols, fatty acid methyl/ethyl esters, and fatty alka(e)nes, have a wide range of industrial applications including plastics, lubricants, and fuels. Currently, these chemicals are obtained mainly through chemical synthesis, which is complex and costly, and their availability from natural biological sources is extremely limited. Metabolic engineering of microorganisms has provided a platform for effective production of these valuable biochemicals. Notably, synthetic biology-based metabolic engineering strategies have been extensively applied to refactor microorganisms for improved biochemical production. Here, we reviewed: (i) the current status of metabolic engineering of microbes that produce fatty acid-derived valuable chemicals, and (ii) the recent progress of synthetic biology approaches that assist metabolic engineering, such as mRNA secondary structure engineering, sensor-regulator system, regulatable expression system, ultrasensitive input/output control system, and computer science-based design of complex gene circuits. Furthermore, key challenges and strategies were discussed. Finally, we concluded that synthetic biology provides useful metabolic engineering strategies for economically viable production of fatty acid-derived valuable chemicals in engineered microbes.

Production of Fatty Acid-Derived Valuable Chemicals in Synthetic Microbes

Energy Technology Data Exchange (ETDEWEB)

Yu, Ai-Qun; Pratomo Juwono, Nina Kurniasih [Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (Singapore); Synthetic Biology Research Program, National University of Singapore, Singapore (Singapore); Leong, Susanna Su Jan [Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (Singapore); Synthetic Biology Research Program, National University of Singapore, Singapore (Singapore); Singapore Institute of Technology, Singapore (Singapore); Chang, Matthew Wook, E-mail: bchcmw@nus.edu.sg [Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (Singapore); Synthetic Biology Research Program, National University of Singapore, Singapore (Singapore)

2014-12-23

Fatty acid derivatives, such as hydroxy fatty acids, fatty alcohols, fatty acid methyl/ethyl esters, and fatty alka(e)nes, have a wide range of industrial applications including plastics, lubricants, and fuels. Currently, these chemicals are obtained mainly through chemical synthesis, which is complex and costly, and their availability from natural biological sources is extremely limited. Metabolic engineering of microorganisms has provided a platform for effective production of these valuable biochemicals. Notably, synthetic biology-based metabolic engineering strategies have been extensively applied to refactor microorganisms for improved biochemical production. Here, we reviewed: (i) the current status of metabolic engineering of microbes that produce fatty acid-derived valuable chemicals, and (ii) the recent progress of synthetic biology approaches that assist metabolic engineering, such as mRNA secondary structure engineering, sensor-regulator system, regulatable expression system, ultrasensitive input/output control system, and computer science-based design of complex gene circuits. Furthermore, key challenges and strategies were discussed. Finally, we concluded that synthetic biology provides useful metabolic engineering strategies for economically viable production of fatty acid-derived valuable chemicals in engineered microbes.

Differential effects of temperature on acid-activated currents mediated by TRPV1 and ASIC channels in rat dorsal root ganglion neurons.

Science.gov (United States)

Neelands, Torben R; Zhang, Xu-Feng; McDonald, Heath; Puttfarcken, Pamela

2010-05-06

Elevated temperature and decreased extracellular pH are hallmarks of inflammatory pain states. Dorsal root ganglia (DRG) neurons are integral in transferring painful stimuli from the periphery to central sites. This study investigated the effect of elevated temperatures on the response of DRG neurons to acute application of acidic solutions. At room temperature (22 degrees C), in response to pH 5.5, there were a variety of kinetic responses consistent with differential expression of TRPV1 and ASIC channels. Increasing the temperature resulted in a significant increase in the peak and total current mediated by TRPV1 in response to an acidic solution. In contrast, the amplitude of a fast activating, rapidly inactivating ASIC1-like current was not affected by increasing the temperature but did result in an increased rate of desensitization that reduced the total current level. This effect on the rate of desensitization was temperature-dependent and could be reversed by returning to 22 degrees C. Likewise, cells exhibiting slowly inactivating ASIC2-like responses also had temperature-dependent increase in the rate of desensitization. The ASIC2-like responses and the TRPV1 responses tended to decrease in amplitude with repetitive application of pH 5.5 even at 22 degrees C. The rate of desensitization of ASIC-like currents activated by less acidic solutions (pH 6.8) was also increased in a temperature-dependent manner. Finally, acidic pH reduced threshold to trigger action potentials, however, the pattern of action potential firing was shaped by the distribution of ASIC and TRPV1 channels. These results indicate that the ambient temperature at which acidosis occurs has a profound effect on the contribution of ASIC and TRPV1 channels, therefore, altering the neuronal excitability. Copyright 2010 Elsevier B.V. All rights reserved.

Regenerative endodontics as a tissue engineering approach: past, current and future.

Science.gov (United States)

Malhotra, Neeraj; Mala, Kundabala

2012-12-01

With the reported startling statistics of high incidence of tooth decay and tooth loss, the current interest is focused on the development of alternate dental tissue replacement therapies. This has led to the application of dental tissue engineering as a clinically relevant method for the regeneration of dental tissues and generation of bioengineered whole tooth. Although, tissue engineering approach requires the three main key elements of stem cells, scaffold and morphogens, a conductive environment (fourth element) is equally important for successful engineering of any tissue and/or organ. The applications of this science has evolved continuously in dentistry, beginning from the application of Ca(OH)(2) in vital pulp therapy to the development of a fully functional bioengineered tooth (mice). Thus, with advances in basic research, recent reports and studies have shown successful application of tissue engineering in the field of dentistry. However, certain practical obstacles are yet to be overcome before dental tissue regeneration can be applied as evidence-based approach in clinics. The article highlights on the past achievements, current developments and future prospects of tissue engineering and regenerative therapy in the field of endodontics and bioengineered teeth (bioteeth). © 2012 The Authors. Australian Endodontic Journal © 2012 Australian Society of Endodontology.

Integrodifferential approach to solution of eddy currents in linear structures with motion

Czech Academy of Sciences Publication Activity Database

Doležel, Ivo; Karban, P.; Donátová, M.; Šolín, Pavel

2010-01-01

Roč. 80, č. 8 (2010), s. 1636-1646 ISSN 0378-4754 R&D Projects: GA ČR(CZ) GA102/07/0496 Institutional research plan: CEZ:AV0Z20570509 Keywords : eddy currents * integrodifferential approach * numerical analysis Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.812, year: 2010 www.elsevier.com/locate/matcom

Current applications and different approaches for microbial L-asparaginase production

Directory of Open Access Journals (Sweden)

Jorge Javier Muso Cachumba

Full Text Available ABSTRACT L-asparaginase (EC 3.5.1.1 is an enzyme that catalysis mainly the asparagine hydrolysis in L-aspartic acid and ammonium. This enzyme is presented in different organisms, such as microorganisms, vegetal, and some animals, including certain rodent's serum, but not unveiled in humans. It can be used as important chemotherapeutic agent for the treatment of a variety of lymphoproliferative disorders and lymphomas (particularly acute lymphoblastic leukemia (ALL and Hodgkin's lymphoma, and has been a pivotal agent in chemotherapy protocols from around 30 years. Also, other important application is in food industry, by using the properties of this enzyme to reduce acrylamide levels in commercial fried foods, maintaining their characteristics (color, flavor, texture, security, etc. Actually, L-asparaginase catalyzes the hydrolysis of L-asparagine, not allowing the reaction of reducing sugars with this aminoacid for the generation of acrylamide. Currently, production of L-asparaginase is mainly based in biotechnological production by using some bacteria. However, industrial production also needs research work aiming to obtain better production yields, as well as novel process by applying different microorganisms to increase the range of applications of the produced enzyme. Within this context, this mini-review presents L-asparaginase applications, production by different microorganisms and some limitations, current investigations, as well as some challenges to be achieved for profitable industrial production.

Current Methods Applied to Biomaterials - Characterization Approaches, Safety Assessment and Biological International Standards.

Science.gov (United States)

Oliveira, Justine P R; Ortiz, H Ivan Melendez; Bucio, Emilio; Alves, Patricia Terra; Lima, Mayara Ingrid Sousa; Goulart, Luiz Ricardo; Mathor, Monica B; Varca, Gustavo H C; Lugao, Ademar B

2018-04-10

Safety and biocompatibility assessment of biomaterials are themes of constant concern as advanced materials enter the market as well as products manufactured by new techniques emerge. Within this context, this review provides an up-to-date approach on current methods for the characterization and safety assessment of biomaterials and biomedical devices from a physicalchemical to a biological perspective, including a description of the alternative methods in accordance with current and established international standards. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Simple Approaches to Minimally-Instrumented, Microfluidic-Based Point-of-Care Nucleic Acid Amplification Tests

Science.gov (United States)

Mauk, Michael G.; Song, Jinzhao; Liu, Changchun; Bau, Haim H.

2018-01-01

Designs and applications of microfluidics-based devices for molecular diagnostics (Nucleic Acid Amplification Tests, NAATs) in infectious disease testing are reviewed, with emphasis on minimally instrumented, point-of-care (POC) tests for resource-limited settings. Microfluidic cartridges (‘chips’) that combine solid-phase nucleic acid extraction; isothermal enzymatic nucleic acid amplification; pre-stored, paraffin-encapsulated lyophilized reagents; and real-time or endpoint optical detection are described. These chips can be used with a companion module for separating plasma from blood through a combined sedimentation-filtration effect. Three reporter types: Fluorescence, colorimetric dyes, and bioluminescence; and a new paradigm for end-point detection based on a diffusion-reaction column are compared. Multiplexing (parallel amplification and detection of multiple targets) is demonstrated. Low-cost detection and added functionality (data analysis, control, communication) can be realized using a cellphone platform with the chip. Some related and similar-purposed approaches by others are surveyed. PMID:29495424

Simple Approaches to Minimally-Instrumented, Microfluidic-Based Point-of-Care Nucleic Acid Amplification Tests

Directory of Open Access Journals (Sweden)

Michael G. Mauk

2018-02-01

Full Text Available Designs and applications of microfluidics-based devices for molecular diagnostics (Nucleic Acid Amplification Tests, NAATs in infectious disease testing are reviewed, with emphasis on minimally instrumented, point-of-care (POC tests for resource-limited settings. Microfluidic cartridges (‘chips’ that combine solid-phase nucleic acid extraction; isothermal enzymatic nucleic acid amplification; pre-stored, paraffin-encapsulated lyophilized reagents; and real-time or endpoint optical detection are described. These chips can be used with a companion module for separating plasma from blood through a combined sedimentation-filtration effect. Three reporter types: Fluorescence, colorimetric dyes, and bioluminescence; and a new paradigm for end-point detection based on a diffusion-reaction column are compared. Multiplexing (parallel amplification and detection of multiple targets is demonstrated. Low-cost detection and added functionality (data analysis, control, communication can be realized using a cellphone platform with the chip. Some related and similar-purposed approaches by others are surveyed.

Improvement of lactic acid production in Saccharomyces cerevisiae by a deletion of ssb1.

Science.gov (United States)

Lee, Jinsuk J; Crook, Nathan; Sun, Jie; Alper, Hal S

2016-01-01

Polylactic acid (PLA) is an important renewable polymer, but current processes for producing its precursor, lactic acid, suffer from process inefficiencies related to the use of bacterial hosts. Therefore, improving the capacity of Saccharomyces cerevisiae to produce lactic acid is a promising approach to improve industrial production of lactic acid. As one such improvement required, the lactic acid tolerance of yeast must be significantly increased. To enable improved tolerance, we employed an RNAi-mediated genome-wide expression knockdown approach as a means to rapidly identify potential genetic targets. In this approach, several gene knockdown targets were identified which confer increased acid tolerance to S. cerevisiae BY4741, of which knockdown of the ribosome-associated chaperone SSB1 conferred the highest increase (52%). This target was then transferred into a lactic acid-overproducing strain of S. cerevisiae CEN.PK in the form of a knockout and the resulting strain demonstrated up to 33% increased cell growth, 58% increased glucose consumption, and 60% increased L-lactic acid production. As SSB1 contains a close functional homolog SSB2 in yeast, this result was counterintuitive and may point to as-yet-undefined functional differences between SSB1 and SSB2 related to lactic acid production. The final strain produced over 50 g/L of lactic acid in under 60 h of fermentation.

Modelling chloride penetration in concrete using electrical voltage and current approaches

Directory of Open Access Journals (Sweden)

Juan Lizarazo-Marriaga

2011-03-01

Full Text Available This paper reports a research programme aimed at giving a better understanding of the phenomena involved in the chloride penetration in cement-based materials. The general approach used was to solve the Nernst-Planck equation numerically for two physical ideal states that define the possible conditions under which chlorides will move through concrete. These conditions are named in this paper as voltage control and current control. For each condition, experiments and simulations were carried out in order to establish the importance of electrical variables such as voltage and current in modelling chloride transport in concrete. The results of experiments and simulations showed that if those electrical variables are included as key parameters in the modelling of chloride penetration through concrete, a better understanding of this complex phenomenon can be obtained.

Towards an Airframe Noise Prediction Methodology: Survey of Current Approaches

Science.gov (United States)

Farassat, Fereidoun; Casper, Jay H.

2006-01-01

In this paper, we present a critical survey of the current airframe noise (AFN) prediction methodologies. Four methodologies are recognized. These are the fully analytic method, CFD combined with the acoustic analogy, the semi-empirical method and fully numerical method. It is argued that for the immediate need of the aircraft industry, the semi-empirical method based on recent high quality acoustic database is the best available method. The method based on CFD and the Ffowcs William- Hawkings (FW-H) equation with penetrable data surface (FW-Hpds ) has advanced considerably and much experience has been gained in its use. However, more research is needed in the near future particularly in the area of turbulence simulation. The fully numerical method will take longer to reach maturity. Based on the current trends, it is predicted that this method will eventually develop into the method of choice. Both the turbulence simulation and propagation methods need to develop more for this method to become useful. Nonetheless, the authors propose that the method based on a combination of numerical and analytical techniques, e.g., CFD combined with FW-H equation, should also be worked on. In this effort, the current symbolic algebra software will allow more analytical approaches to be incorporated into AFN prediction methods.

The Stewart approach--one clinician's perspective.

Science.gov (United States)

Morgan, T John

2009-05-01

Peter Stewart added controversy to an already troubled subject when he entered the clinical acid-base arena. His approach puts water dissociation at the centre of the acid-base status of body fluids. It is based on six simultaneous equations, incorporating the Laws of Mass Action, Mass Conservation, and Electrical Neutrality. Together with Gibbs-Donnan equilibria, these equations explain the diagnostically important PaCO(2)/pH relationship, and improve understanding of the physiologic basis of traditional acid-base approaches. Spin-offs have included new scanning tools for unmeasured ions, in particular the 'strong ion gap' and 'net unmeasured ions'. The most controversial feature is the designation of pH and bicarbonate concentrations as dependent variables, answerable exclusively to three independent variables. These are the strong ion difference (SID), the total concentration of non-volatile weak acid (A(TOT)), and PCO(2). Aspects of this assertion conflict with traditional renal physiology, and with current models of membrane H(+)/base transporters, oxidative phosphorylation, and proton and bicarbonate ionophores. The debate in this area is ongoing. Meanwhile, Stewart-style diagnostic and decision support systems such as the 'Strong Ion Calculator' and the web-site www.acidbase.org are now appearing.

Current trends to comprehend lipid metabolism in diatoms.

Science.gov (United States)

Zulu, Nodumo Nokulunga; Zienkiewicz, Krzysztof; Vollheyde, Katharina; Feussner, Ivo

2018-04-01

Diatoms are the most dominant phytoplankton species in oceans and they continue to receive a great deal of attention because of their significant contributions in ecosystems and the environment. Due to triacylglycerol (TAG) profiles that are abundant in medium-chain fatty acids, diatoms have emerged to be better feed stocks for biofuel production, in comparison to the commonly studied green microalgal species (chlorophytes). Importantly, diatoms are also known for their high levels of the essential ω3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and are considered to be a promising alternative source of these components. The two most commonly exploited diatoms include Thalassiosira pseudonana and Phaeodactylum tricornutum. Although obvious similarities between diatoms and chlorophytes exist, there are some substantial differences in their lipid metabolism. This review provides an overview on lipid metabolism in diatoms, with P. tricornutum as the most explored model. Special emphasis is placed on the synthesis and incorporation of very long chain ω3 fatty acids into lipids. Furthermore, current approaches including genetic engineering and biotechnological methods aimed at improving and maximizing lipid production in P. tricornutum are also discussed. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Dose-response functions for effects of acidic precipitation on vegetation

Energy Technology Data Exchange (ETDEWEB)

Jacobson, J S; Troiano, J J

1983-01-01

Research on the effect of sulfuric and nitric acids, as well as other substances, in rain on plant growth has focused on quantifying the relationship between doses of acids in precipitation and plant response. After eight years, there has been no direct demonstration of harmful effects to plants by ambient acidic rain in North America, and there remains considerable uncertainty about the potential risk to cultivated and native plants. Current efforts to describe the relationships between dose of acidity and effects on plants need better experimental approaches if the results are to be more relevant to actual field situations. Mechanistic models that describe the physiological and biochemical basis for effects of acidic rain on plants will be needed to provide confidence in the predictions of plant response. 34 references, 1 figure.

Promoting pre-conceptional use of folic acid to Hispanic women: a social marketing approach.

Science.gov (United States)

Quinn, Gwendolyn P; Hauser, Kimberlea; Bell-Ellison, Bethany A; Rodriguez, Nydia Y; Frías, Jaime L

2006-09-01

To develop a culturally appropriate communication initiative in an effort to promote the use of pre-conceptional folic acid among Hispanic women of childbearing age. The materials were designed to communicate information about the risks of neural tube defects and the value of folic acid supplementation before conception. The initiative was developed using a social marketing approach. A series of focus groups were conducted with Hispanic women, particularly Mexican and Mexican-American women, to gain an understanding of their knowledge, attitudes, and behaviors regarding birth defects and folic acid. Additionally focus groups assessed women's preferences for existing folic acid education materials. Qualitative analysis of coded transcripts revealed key themes which were incorporated into a multi-media initiative. Critical themes of the research highlighted the need to include the role of partners and a sense of family in the promotions aimed at these groups. Another key component was the need to dispel myths which act as barriers to pre-conceptional folic acid use. Other important elements included in the media products were the need for Spanish and English versions, an explanation of neural tube defects, and a reference to the cost of the supplements. The final products of the initiative included Spanish and English versions of a brochure, photo-novella, and radio public service announcement. Pre-testing results showed women understood the message, thought the message was for women like them, and expected to begin taking a folic acid supplement. Results of the overall evaluation of the initiative are on-going.

Current Approaches in the Treatment of Relapsed and Refractory Acute Myeloid Leukemia

Science.gov (United States)

Ramos, Nestor R.; Mo, Clifton C.; Karp, Judith E.; Hourigan, Christopher S.

2015-01-01

The limited sensitivity of the historical treatment response criteria for acute myeloid leukemia (AML) has resulted in a different paradigm for treatment compared with most other cancers presenting with widely disseminated disease. Initial cytotoxic induction chemotherapy is often able to reduce tumor burden to a level sufficient to meet the current criteria for “complete” remission. Nevertheless, most AML patients ultimately die from their disease, most commonly as clinically evident relapsed AML. Despite a variety of available salvage therapy options, prognosis in patients with relapsed or refractory AML is generally poor. In this review, we outline the commonly utilized salvage cytotoxic therapy interventions and then highlight novel investigational efforts currently in clinical trials using both pathway-targeted agents and immunotherapy based approaches. We conclude that there is no current standard of care for adult relapsed or refractory AML other than offering referral to an appropriate clinical trial. PMID:25932335

A Phase Current Reconstruction Approach for Three-Phase Permanent-Magnet Synchronous Motor Drive

Directory of Open Access Journals (Sweden)

Hao Yan

2016-10-01

Full Text Available Three-phase permanent-magnet synchronous motors (PMSMs are widely used in renewable energy applications such as wind power generation, tidal energy and electric vehicles owing to their merits such as high efficiency, high precision and high reliability. To reduce the cost and volume of the drive system, techniques of reconstructing three-phase current using a single current sensor have been reported for three-phase alternating current (AC control system using the power converts. In existing studies, the reconstruction precision is largely influenced by reconstructing dead zones on the Space Vector Pulse Width Modulation (SVPWM plane, which requires other algorithms to compensate either by modifying PWM modulation or by phase-shifting of the PWM signal. In this paper, a novel extended phase current reconstruction approach for PMSM drive is proposed. Six novel installation positions are obtained by analyzing the sampling results of the current paths between each two power switches. By arranging the single current sensor at these positions, the single current sensor is sampled during zero voltage vectors (ZVV without modifying the PWM signals. This proposed method can reconstruct the three-phase currents without any complex algorithms and is available in the sector boundary region and low modulation region. Finally, this method is validated by experiments.

Linearized dynamical approach to current algebra

International Nuclear Information System (INIS)

Scadron, M.D.

1995-07-01

We study the original motivations searching for a nonlinear chiral Lagrangian to replace the linear sigma model while manifesting all the successful properties of current algebra and partial conservation of axial currents (PCAC). (author). 26 refs

Challenging the current strategy of radiological protection of the environment: arguments for an ecosystem approach

International Nuclear Information System (INIS)

Brechignac, F.; Doi, Masahiro

2009-01-01

The system of radiological protection of the environment that is currently under development is one contribution to the general need to adequately protect the environment against stress. Dominated by operational goals, it emphasizes conceptual and methodological approaches that are readily accessible today: reference organisms supported by individual-based traditional ecotoxicological data. Whilst there are immediate advantages to this approach (pragmatism, consistency with other approaches in use for man and biota), there are also clear limitations, especially in a longer run perspective, that need to be acknowledged and further considered. One can mention a few: uncertainties generated by the need for various extrapolations (from lower to higher levels of biological organisation, ...), various features missed such as potential ecological impact through impairment of ecosystem processes, trans-generational impacts as mediated through genomic instability, indirect effects mediated through trophic interactions or disruption of ecological balances, ... Such limitations have already been faced in other fields of environmental protection against other stressors, pushing a number of environment professionals to assign stronger emphasis on more systemic approaches. This review discusses the advantages and limitations of the current approach designed for the radiological protection of non-human biota in the broader context of environment protection as a whole, with especial reference to upcoming trends and evolutions. This leads in particular to advocating the need to boost scientific and methodological approaches featuring the ecosystem concept as a mean to access a unified goal of protection: preserving life sustainability through protection of ecosystem structure and functioning.

Challenging the current strategy of radiological protection of the environment: arguments for an ecosystem approach

Energy Technology Data Exchange (ETDEWEB)

Brechignac, F., E-mail: francois.brechignac@irsn. [Institute for Radioprotection and Nuclear Safety (IRSN), Centre d' Etudes de Cadarache, Blg 229, 13115 Saint-Paul-lez-Durance (France); Doi, Masahiro [National Institute of Radiological Sciences, NIRS, Center for Radiation Protection, Regulatory Sciences Research Group, 4-9-1, Anagawa, Inage, Chiba, 263-8555 (Japan)

2009-12-15

The system of radiological protection of the environment that is currently under development is one contribution to the general need to adequately protect the environment against stress. Dominated by operational goals, it emphasizes conceptual and methodological approaches that are readily accessible today: reference organisms supported by individual-based traditional ecotoxicological data. Whilst there are immediate advantages to this approach (pragmatism, consistency with other approaches in use for man and biota), there are also clear limitations, especially in a longer run perspective, that need to be acknowledged and further considered. One can mention a few: uncertainties generated by the need for various extrapolations (from lower to higher levels of biological organisation, ...), various features missed such as potential ecological impact through impairment of ecosystem processes, trans-generational impacts as mediated through genomic instability, indirect effects mediated through trophic interactions or disruption of ecological balances, ... Such limitations have already been faced in other fields of environmental protection against other stressors, pushing a number of environment professionals to assign stronger emphasis on more systemic approaches. This review discusses the advantages and limitations of the current approach designed for the radiological protection of non-human biota in the broader context of environment protection as a whole, with especial reference to upcoming trends and evolutions. This leads in particular to advocating the need to boost scientific and methodological approaches featuring the ecosystem concept as a mean to access a unified goal of protection: preserving life sustainability through protection of ecosystem structure and functioning.

Cognitive-behavior therapy for problem gambling: a critique of current treatments and proposed new unified approach.

Science.gov (United States)

Tolchard, Barry

2017-06-01

There is evidence supporting the use of cognitive-behavioral therapy (CBT) in the treatment of problem gambling. Despite this, little is known about how CBT works and which particular approach is most effective. This paper aims to synthesize the evidence for current CBT and propose a more unified approach to treatment. A literature review and narrative synthesis of the current research evidence of CBT for the treatment of problem gambling was conducted, focusing on the underlying mechanisms within the treatment approach. Several CBT approaches were critiqued. These can be divided into forms of exposure therapy (including aversion techniques, systematic desensitization and other behavioral experiments) those focusing on cognitive restructuring techniques (such as reinforcement of nongambling activity, use of diaries, motivational enhancement and audio-playback techniques and third wave techniques including mindfulness. Findings, in relation to the treatment actions, from this synthesis are reported. The debate surrounding the treatment of problem gambling has been conducted as an either/or rather than a both/and discourse. This paper proposes a new, unified approach to the treatment of problem gambling that incorporates the best elements of both exposure and cognitive restructuring techniques, alongside the use of techniques borrowed from mindfulness and other CBT approaches.

Current issues surrounding the definition of trans-fatty acids: implications for health, industry and food labels.

Science.gov (United States)

Wang, Ye; Proctor, Spencer D

2013-10-01

The definition of trans-fatty acids (TFA) was established by the Codex Alimentarius to guide nutritional and legislative regulations to reduce TFA consumption. Currently, conjugated linoleic acid (CLA) is excluded from the TFA definition based on evidence (primarily preclinical studies) implying health benefits on weight management and cancer prevention. While the efficacy of CLA supplements remains inconsistent in randomised clinical trials, evidence has emerged to associate supplemental CLA with negative health outcomes, including increased subclinical inflammation and oxidative stress (particularly at high doses). This has resulted in concerns regarding the correctness of excluding CLA from the TFA definition. Here we review recent clinical and preclinical literature on health implications of CLA and ruminant TFA, and highlight several issues surrounding the current Codex definition of TFA and how it may influence interpretation for public health. We find that CLA derived from ruminant foods differ from commercial CLA supplements in their isomer composition/distribution, consumption level and bioactivity. We conclude that health concerns associated with the use of supplemental CLA do not repudiate the exclusion of all forms of CLA from the Codex TFA definition, particularly when using the definition for food-related purposes. Given the emerging differential bioactivity of TFA from industrial v. ruminant sources, we advocate that regional nutrition guidelines/policies should focus on eliminating industrial forms of trans-fat from processed foods as opposed to all TFA per se.

A review of treatment strategies for hydrofluoric acid burns: current status and future prospects.

Science.gov (United States)

Wang, Xingang; Zhang, Yuanhai; Ni, Liangfang; You, Chuangang; Ye, Chunjiang; Jiang, Ruiming; Liu, Liping; Liu, Jia; Han, Chunmao

2014-12-01

Hydrofluoric acid (HF), a dangerous inorganic acid, can cause severe corrosive effects and systemic toxicity. HF enters the human body via where it contacts, such as skin and mucosa, alimentary and respiratory tracts, and ocular surfaces. In the recent years, the incidence of HF burn has tended to increase over time. The injury mechanism of HF is associated primarily with the massive absorption of HF and the release of hydrogen ions. Correct diagnosis and timely treatment are especially important for HF burns. The critical procedure to treat HF burn is to prevent on-going HF absorption, and block the progressive destruction caused by fluoride ions. Due to the distinct characteristics of HF burns, the topical treatment, as well as systemic support, has been emphasised. Whereas, management of patients with HF burns remains a great challenge in some situations. To date, there has been no widely accepted protocol for the rescue of HF burns, partly due to the diversity of HF burns. This paper overviews the current status and problems of treatment strategies for HF burns, for the purpose of promoting the future researches and improvement. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

3-D time-domain induced polarization tomography: a new approach based on a source current density formulation

Science.gov (United States)

Soueid Ahmed, A.; Revil, A.

2018-04-01

Induced polarization (IP) of porous rocks can be associated with a secondary source current density, which is proportional to both the intrinsic chargeability and the primary (applied) current density. This gives the possibility of reformulating the time domain induced polarization (TDIP) problem as a time-dependent self-potential-type problem. This new approach implies a change of strategy regarding data acquisition and inversion, allowing major time savings for both. For inverting TDIP data, we first retrieve the electrical resistivity distribution. Then, we use this electrical resistivity distribution to reconstruct the primary current density during the injection/retrieval of the (primary) current between the current electrodes A and B. The time-lapse secondary source current density distribution is determined given the primary source current density and a distribution of chargeability (forward modelling step). The inverse problem is linear between the secondary voltages (measured at all the electrodes) and the computed secondary source current density. A kernel matrix relating the secondary observed voltages data to the source current density model is computed once (using the electrical conductivity distribution), and then used throughout the inversion process. This recovered source current density model is in turn used to estimate the time-dependent chargeability (normalized voltages) in each cell of the domain of interest. Assuming a Cole-Cole model for simplicity, we can reconstruct the 3-D distributions of the relaxation time τ and the Cole-Cole exponent c by fitting the intrinsic chargeability decay curve to a Cole-Cole relaxation model for each cell. Two simple cases are studied in details to explain this new approach. In the first case, we estimate the Cole-Cole parameters as well as the source current density field from a synthetic TDIP data set. Our approach is successfully able to reveal the presence of the anomaly and to invert its Cole

OSTEOARTHRITIS: CURRENT CLINICAL CONCEPT AND SOME PROMISING THERAPEUTIC APPROACHES

Directory of Open Access Journals (Sweden)

A. E. Karateev

2018-01-01

Full Text Available In recent years, there has been a trend toward changing the clinical concept of osteoarthritis (OA. This disease has been considered as an age-related disease and the long-term result of a current pathological process for a very long time. However, many experts are now inclined to consider it necessary to identify the early, pre-X-ray stage of OA, when adequate treatment may not only halt the progression, but also achieve the regression of joint structural changes. This review deals with a number of pathogenetic and clinical aspects of the early stages of OA, which are important for timely diagnosis and pathogenetic therapy choice. It also considers some therapeutic approaches, both a "classic" and recently actively discussed methods for using platelet-rich plasma and autologous chondrocyte transplantation.

Current Approaches for Control Room I and C Modernization

International Nuclear Information System (INIS)

Lopez, Alberto; Jimenez, Alfonso

2002-01-01

In general, instrumentation and control (I and C) systems for nuclear power plants were made using analogic systems and relays, since this was the only technology available by the time these systems were designed. This fact impacts on the operational and maintenance capabilities required to these systems. For this reason, nuclear power plants are facing nowadays two challenges: on one hand, the obsolescence of these systems contributes to the increase in the operation and maintenance costs - due to the difficulties for getting spare parts and support from the system vendors -. On the other hand, there has been an increase in the utilities competitiveness due to the electric power market liberalization. All this, of course, along with the commitment to maintain the current safety levels and meet the new requirements and standards that may arise in the near future. The application of current technologies, especially digital technology, solves the obsolescence problems and allows for a more functional and updated human-machine interface. Nevertheless, the cost associated to these modifications makes it necessary to develop strategies to determine which systems need to be modified and how to implement modifications effectively, so that these systems can work jointly with others using different technologies. Other issues inherent to digital technology must be considered, such as verification and validation of the software and of the human-machine interface, which are required for its licensing. This presentation describes the current approaches for I and C modernization, the main reasons, technologies and implementation plans, focusing on the control room and on the impact on operations. The main issues to be considered for developing a specific modernization plan are analysed. The goals and status of the 'Feasibility Study of the Control Room I and C Modernization' are described. This study is currently being developed by Endesa, Iberdrola and Tecnatom, and is included

The Current Role of Omega-3 Fatty Acids in the Management of Atrial Fibrillation

Directory of Open Access Journals (Sweden)

Georgios A. Christou

2015-09-01

Full Text Available Background: The main dietary source of omega-3 polyunsaturated fatty acids (n-3 PUFA is fish, which contains eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. In the present manuscript, we aimed to review the current evidence regarding the clinical role of n-3 PUFA in the prevention of atrial fibrillation (AF and the possible underlying mechanisms. Methods: A literature search based on PubMed listings was performed using “Omega-3 fatty acids” and “atrial fibrilation” as key search terms. Results: n-3 PUFA have been shown to attenuate structural atrial remodeling, prolong atrial effective refractory period through the prevention of reentry and suppress ectopic firing from pulmonary veins. Dietary fish intake has been found to have no effect on the incidence of AF in the majority of studies. Circulating DHA has been consistently reported to be inversely associated with AF risk, whereas EPA has no such effect. The majority of studies investigating the impact of n-3 PUFA supplementation on the incidence of AF following cardiac surgery reported no benefit, though most of them did not use n-3 PUFA pretreatment for adequate duration. Studies using adequate four-week pretreatment with n-3 PUFA before cardioversion of AF showed a reduction of the AF incidence. Conclusions: Although n-3 PUFA have antiarrhythmogenic properties, their clinical efficacy on the prevention of AF is not consistently supported. Further well-designed studies are needed to overcome the limitations of the existing studies and provide robust conclusions.

Process Design Report for Wood Feedstock: Lignocellulosic Biomass to Ethanol Process Desing and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis Current and Futuristic Scenarios

Energy Technology Data Exchange (ETDEWEB)

Wooley, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ruth, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sheehan, John [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ibsen, Kelly [National Renewable Energy Lab. (NREL), Golden, CO (United States); Majdeski, Henry [Delta-T Corporation, Lexington, KY (United States); Galves, Adrian [Delta-T Corporation, Lexington, KY (United States)

1999-07-01

The National Renewable Energy Laboratory (NREL) has undertaken a complete review and update of the process design and economic model for the biomass-to-ethanol process based on co-current dilute acid prehydrolysis, along with simultaneous saccharification (enzymatic) and co-fermentation. The process design includes the core technologies being researched by the U.S. Department of Energy (DOE): prehydrolysis, simultaneous saccharification and co-fermentation, and cellulase enzyme production.

A clinical trial with combined transcranial direct current stimulation and alcohol approach bias retraining

NARCIS (Netherlands)

den Uyl, T.E.; Gladwin, T.E.; Rinck, M.; Lindenmeyer, J.; Wiers, R.W.

2017-01-01

Two studies showed an improvement in clinical outcomes after alcohol approach bias retraining, a form of Cognitive Bias Modification (CBM). We investigated whether transcranial direct current stimulation (tDCS) could enhance effects of CBM. TDCS is a neuromodulation technique that can increase

Downstream process development in biotechnological itaconic acid manufacturing.

Science.gov (United States)

Magalhães, Antonio Irineudo; de Carvalho, Júlio Cesar; Medina, Jesus David Coral; Soccol, Carlos Ricardo

2017-01-01

Itaconic acid is a promising chemical that has a wide range of applications and can be obtained in large scale using fermentation processes. One of the most important uses of this biomonomer is the environmentally sustainable production of biopolymers. Separation of itaconic acid from the fermented broth has a considerable impact in the total production cost. Therefore, optimization and high efficiency downstream processes are technological challenges to make biorefineries sustainable and economically viable. This review describes the current state of the art in recovery and purification for itaconic acid production via bioprocesses. Previous studies on the separation of itaconic acid relying on operations such as crystallization, precipitation, extraction, electrodialysis, diafiltration, pertraction, and adsorption. Although crystallization is a typical method of itaconic acid separation from fermented broth, other methods such as membrane separation and reactive extraction are promising as a recovery steps coupled to the fermentation, potentially enhancing the overall process yield. Another approach is adsorption in fixed bed columns, which efficiently separates itaconic acid. Despite recent advances in separation and recovery methods, there is still space for improvement in IA recovery and purification.

Influence of acid diffusion on the performance of lead-acid cells

Energy Technology Data Exchange (ETDEWEB)

Kappus, W.; Bohmann, J.

1983-11-01

A model for the discharge performance of the lead-acid cell is proposed. Diffusion of acid into the porous electrodes, which is connected with diffusional polarization, is considered as the principal factor in the transport process. The end of discharge is determined either by acid depletion inside the electrodes or by exhaustion of the active material, where utilization of the active material as a function of the acid density and the specific current is determined from empirical expressions. Curves of diffusional polarizations as a function of the discharge time are presented. Calculated discharge capacities show the influence of various parameters such as electrode thickness, current, and acid density. Tubular and pasted plates are considered.

Poly(3,4-ethylenedioxythiophene-co-(5-amino-2-naphthalenesulfonic acid)) (PEDOT-PANS) film modified glassy carbon electrode for selective detection of dopamine in the presence of ascorbic acid and uric acid

International Nuclear Information System (INIS)

Balamurugan, A.; Chen Shenming

2007-01-01

Poly(3,4-ethylenedioxythiophene-co-(5-amino-2-naphthalenesulfonic acid)) (PEDOT-PANS) film modified glassy carbon electrode was prepared by electrochemical polymerization technique. The properties of modified electrode was studied. It was found that the electrochemical properties of modified electrode was very much dependent on the experimental conditions, such as monomer oxidation potential and pH. The modified electrode surface was characterized by scanning electron microscopy (SEM). The PEDOT-PANS film modified electrode shows electrocatalytic activity toward oxidation of dopamine (DA) in acetate buffer solution (pH 5.0) and results in a marked enhancement of the current response. The linear sweep voltammetric (LSV) peak heights are linear with DA concentration from 2 x 10 -6 to 1 x 10 -5 M. The detection limit is 5 x 10 -7 M. More over, the interferences of ascorbic acid (AA) and uric acid (UA) were effectively diminished. This work provides a simple and easy approach for selective determination of dopamine in the presence of ascorbic acid and uric acid

Amino Acid Prodrugs: An Approach to Improve the Absorption of HIV-1 Protease Inhibitor, Lopinavir

Directory of Open Access Journals (Sweden)

Mitesh Patel

2014-04-01

Full Text Available Poor systemic concentrations of lopinavir (LPV following oral administration occur due to high cellular efflux by P-glycoprotein (P-gp and multidrug resistance-associated proteins (MRPs and extensive metabolism by CYP3A4 enzymes. In this study, amino acid prodrugs of LPV were designed and investigated for their potential to circumvent efflux processes and first pass effects. Three amino acid prodrugs were synthesized by conjugating isoleucine, tryptophan and methionine to LPV. Prodrug formation was confirmed by the LCMS/MS and NMR technique. Interaction of LPV prodrugs with efflux proteins were carried out in P-gp (MDCK-MDR1 and MRP2 (MDCK-MRP2 transfected cells. Aqueous solubility studies demonstrated that prodrugs generate higher solubility relative to LPV. Prodrugs displayed higher stability under acidic conditions and degraded significantly with rise in pH. Uptake and transport data suggested that prodrugs carry significantly lower affinity towards P-gp and MRP2 relative to LPV. Moreover, prodrugs exhibited higher liver microsomal stability relative to LPV. Hence, amino acid prodrug modification might be a viable approach for enhancing LPV absorption across intestinal epithelial and brain endothelial cells which expresses high levels of P-gp and MRP2.

Effects of current density and electrolyte temperature on the volume expansion factor of anodic alumina formed in oxalic acid

International Nuclear Information System (INIS)

Zhou, F.; Baron-Wiecheć, A.; Garcia-Vergara, S.J.; Curioni, M.; Habazaki, H.; Skeldon, P.; Thompson, G.E.

2012-01-01

The formation of porous anodic alumina in 0.4 M oxalic acid is investigated over a range of current density and electrolyte temperature using sputtering-deposited substrates containing tungsten tracer layers. The findings reveal volume expansion factors and efficiencies of film growth that increase with the increase of the current density and decrease of the temperature. Pore generation by the flow of the anodic alumina in the barrier layer toward the pore walls is proposed to dominate at relatively high current densities (above ∼2 mA cm −2 ), with tungsten tracer species being retained within films. Conversely, losses of tungsten species occur at lower current densities, possibly due to increased field-assisted ejection of Al 3+ ions and/or field-assisted dissolution of the anodic alumina.

Dual Effects of Alpha-Hydroxy Acids on the Skin

Directory of Open Access Journals (Sweden)

Sheau-Chung Tang

2018-04-01

Full Text Available AHAs are organic acids with one hydroxyl group attached to the alpha position of the acid. AHAs including glycolic acid, lactic acid, malic acid, tartaric acid, and citric acid are often used extensively in cosmetic formulations. AHAs have been used as superficial peeling agents as well as to ameliorate the appearance of keratoses and acne in dermatology. However, caution should be exercised in relation to certain adverse reactions among patients using products with AHAs, including swelling, burning, and pruritus. Whether AHAs enhance or decrease photo damage of the skin remains unclear, compelling us to ask the question, is AHA a friend or a foe of the skin? The aim of this manuscript is to review the various biological effects and mechanisms of AHAs on human keratinocytes and in an animal model. We conclude that whether AHA is a friend or foe of human skin depends on its concentration. These mechanisms of AHAs are currently well understood, aiding the development of novel approaches for the prevention of UV-induced skin damage.

Prediction of protein structural classes by Chou's pseudo amino acid composition: approached using continuous wavelet transform and principal component analysis.

Science.gov (United States)

Li, Zhan-Chao; Zhou, Xi-Bin; Dai, Zong; Zou, Xiao-Yong

2009-07-01

A prior knowledge of protein structural classes can provide useful information about its overall structure, so it is very important for quick and accurate determination of protein structural class with computation method in protein science. One of the key for computation method is accurate protein sample representation. Here, based on the concept of Chou's pseudo-amino acid composition (AAC, Chou, Proteins: structure, function, and genetics, 43:246-255, 2001), a novel method of feature extraction that combined continuous wavelet transform (CWT) with principal component analysis (PCA) was introduced for the prediction of protein structural classes. Firstly, the digital signal was obtained by mapping each amino acid according to various physicochemical properties. Secondly, CWT was utilized to extract new feature vector based on wavelet power spectrum (WPS), which contains more abundant information of sequence order in frequency domain and time domain, and PCA was then used to reorganize the feature vector to decrease information redundancy and computational complexity. Finally, a pseudo-amino acid composition feature vector was further formed to represent primary sequence by coupling AAC vector with a set of new feature vector of WPS in an orthogonal space by PCA. As a showcase, the rigorous jackknife cross-validation test was performed on the working datasets. The results indicated that prediction quality has been improved, and the current approach of protein representation may serve as a useful complementary vehicle in classifying other attributes of proteins, such as enzyme family class, subcellular localization, membrane protein types and protein secondary structure, etc.

Current and future perspectives on the development, evaluation and application of in silico approaches for predicting toxicity

Science.gov (United States)

Safety-related problems continue to be one of the major reasons of attrition in drug development. Non-testing approaches to predict toxicity could form part of the solution. This review provides a perspective of current status of non-testing approaches available for the predictio...

A novel approach for rapidly and cost-effectively assessing toxicity of toxic metals in acidic water using an acidophilic iron-oxidizing biosensor.

Science.gov (United States)

Yang, Shih-Hung; Cheng, Kuo-Chih; Liao, Vivian Hsiu-Chuan

2017-11-01

Contamination by heavy metals and metalloids is a serious environmental and health concern. Acidic wastewaters are often associated with toxic metals which may enter and spread into agricultural soils. Several biological assays have been developed to detect toxic metals; however, most of them can only detect toxic metals in a neutral pH, not in an acidic environment. In this study, an acidophilic iron-oxidizing bacterium (IOB) Strain Y10 was isolated, characterized, and used to detect toxic metals toxicity in acidic water at pH 2.5. The colorimetric acidophilic IOB biosensor was based on the inhibition of the iron oxidizing ability of Strain Y10, an acidophilic iron-oxidizing bacterium, by metals toxicity. Our results showed that Strain Y10 is acidophilic iron-oxidizing bacterium. Thiobacillus caldus medium (TCM) (pH 2.5) supplied with both S 4 O 6 2- and glucose was the optimum growth medium for Strain Y10. The optimum temperature and pH for the growth of Strain Y10 was 45 °C and pH 2.5, respectively. Our study demonstrates that the color-based acidophilic IOB biosensor can be semi-quantitatively observed by eye or quantitatively measured by spectrometer to detect toxicity from multiple toxic metals at pH 2.5 within 45 min. Our study shows that monitoring toxic metals in acidic water is possible by using the acidophilic IOB biosensor. Our study thus provides a novel approach for rapid and cost-effective detection of toxic metals in acidic conditions that can otherwise compromise current methods of chemical analysis. This method also allows for increased efficiency when screening large numbers of environmental samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Current Approaches to the Establishment of Credit Risk Specific Provisions

Directory of Open Access Journals (Sweden)

Ion Nitu

2008-10-01

Full Text Available The aim of the new Basel II and IFRS approaches is to make the operations of financial institutions more transparent and thus to create a better basis for the market participants and supervisory authorities to acquire information and make decisions. In the banking sector, a continuous debate is being led, related to the similarities and differences between IFRS approach on loan loss provisions and Basel II approach on calculating the capital requirements, judging against the classical method regarding loan provisions, currently used by the Romanian banks following the Central Bank’s regulations.Banks must take into consideration that IFRS and Basel II objectives are fundamentally different. While IFRS aims to ensure that the financial papers reflect adequately the losses recorded at each balance sheet date, the Basel II objective is to ensure that the bank has enough provisions or capital in order to face expected losses in the next 12 months and eventual unexpected losses.Consequently, there are clear differences between the objectives of the two models. Basel II works on statistical modeling of expected losses while IFRS, although allowing statistical models, requires a trigger event to have occurred before they can be used. IAS 39 specifically states that losses that are expected as a result of future events, no matter how likely, are not recognized. This is a clear and fundamental area of difference between the two frameworks.

Acid-base equilibrium: The best clinical approach

OpenAIRE

Aristizábal-Salazar, Raúl E; Calvo-Torres, L. Felipe; Valencia-Arango, Luis Alfonso; Montoya-Canon, Mauricio; Barbosa-Gantiva, Oscar; Hincapié-Baena, Vanessa

2015-01-01

Acid-base balance disorders can be found in a primary or secondary form in patients with a disease process such as Diabetes Mellitus or acute renal failure, among others. The objective of this article is to explain and guide the correlation ship between the clinical findings in the patient and the parameters of arterial blood gases in a simple and precise manner, in order to make the correct acid-base balance diagnosis and adequate therapeutic interventions. A non-systematic review of the sci...

Tranexamic acid for the management of uterine fibroid tumors: A systematic review of the current evidence

Science.gov (United States)

Peitsidis, Panagiotis; Koukoulomati, Anna

2014-01-01

AIM: To conduct a detailed systematic review of the current evidence on the administration and efficacy of tranexamic acid in patients with menorrhagia due to uterine fibroids. METHODS: We conducted an electronic search on the following databases PubMed and Medline (1950-2013); (1980-2013); Cochrane library (1993-2013). RESULTS: A total of 36 articles were retrieved after the initial electronic search. Careful assessment of the retrieved studies led to the final selection of 5 articles for inclusion in the review. CONCLUSION: Tranexamic acid may reduce blood loss perioperatively in myomectomies. It may reduce the menorrhagia in patients with fibroids, however a stratification of fibroids by size and location is required to define the responses. It is safe in general, with mild adverse effects observed in some cases. More studies with a double-blind randomized design and larger numbers of participants are necessary to reach more precise and safe conclusions. PMID:25516866

How is the Current Nano/Microscopic Knowledge Implemented in Model Approaches?

International Nuclear Information System (INIS)

Rotenberg, Benjamin

2013-01-01

The recent developments of experimental techniques have opened new opportunities and challenges for the modelling and simulation of clay materials, on various scales. In this communication, several aspects of the interaction between experimental and modelling approaches will be presented and dis-cussed. What levels of modelling are available depending on the target property and what experimental input is required? How can experimental information be used to validate models? What knowledge can modelling on different scale bring to the knowledge on the physical properties of clays? Finally, what can we do when experimental information is not available? Models implement the current nano/microscopic knowledge using experimental input, taking advantage of multi-scale approaches, and providing data or insights complementary to experiments. Future work will greatly benefit from the recent experimental developments, in particular for 3D-imaging on intermediate scales, and should also address other properties, e.g. mechanical or thermal properties. (authors)

Current approaches to the diagnosis, treatment, and reporting of trichomoniasis and candidosis.

Science.gov (United States)

O'Connor, B H; Adler, M W

1979-02-01

The current approach to the management of trichomoniasis and candidosis in sexually transmitted disease (STD) clinics in England and Wales is described. Microscopy alone was used in the diagnosis of trichomoniasis in 44% of clinics and of candidosis in 35% of clinics. Oral metronidazole was used for the treatment of trichomoniasis in women in 92% of clinics. Vaginal pessaries containing nystatin or clotrimazole were routinely used to treat candidosis in 95% of clinics. Male sexual contacts of female patients with candidosis and trichomoniasis were invited to attend for examination in 88% of clinics. Physicians in 81% of clinics prescribed treatment on epidemiological grounds for male contacts of female patients with trichomoniasis. A more uniform approach to the diagnostic categories used for the quarterly returns for cases treated epidemiologically is recommended.

The "high solubility" definition of the current FDA Guidance on Biopharmaceutical Classification System may be too strict for acidic drugs.

Science.gov (United States)

Yazdanian, Mehran; Briggs, Katherine; Jankovsky, Corinne; Hawi, Amale

2004-02-01

The purpose of this study was to assess if the definition of high solubility as proposed in the FDA Guidance on Biopharmaceutical Classification System (BCS) is too strict for highly permeable acidic drugs. The solubility and permeability values of 20 (18 acidic and 2 non-acidic) nonsteroidal anti-inflammatory drugs (NSAID) were determined. The NSAIDs were grouped into three different sets having acetic acid, propionic acid, or other acidic moieties such as fenamate, oxicam, and salicylate. Two nonacidic NSAIDs (celecoxib and rofecoxib) were also included for comparison purposes. Equilibrium solubility values were determined at pH 1.2, 5.0, 7.4, and in biorelevant media simulating fed intestinal fluid at pH 5.0. For a select number of acids, we also measured solubility values in media simulating gastric and fasted intestinal fluids. Permeability classification was established relative to that of reference drugs in the Caco-2 cell permeability model. Permeability coefficients for all drugs were measured at concentrations corresponding to the lowest and highest marketed dose strengths dissolved in 250 ml volume, and their potential interaction with cellular efflux pumps was investigated. All NSAIDs with different acidic functional groups were classified as highly permeable based on their Caco-2 cell permeability. Only ketorolac appeared to have a potential for interaction with cellular efflux pumps. Solubility classification was based on comparison of equilibrium solubility at pH 1.2, 5.0. and 7.4 relative to marketed dose strengths in 250 ml. The pKa values for the acidic NSAIDs studied were between 3.5 and 5.1. and, as expected, their solubility increased dramatically at pH 7.4 compared to pH 1.2. Only three NSAIDs, ketorolac, ketoprofen. and acetyl salicylic acid, meet the current criteria for high solubility over the entire pH range. However, with the exception of ibuprofen, oxaprozin, and mefenamic acid, the remaining compounds can be classified as Class I drugs

Ursodeoxycholic acid prevents ventricular conduction slowing and arrhythmia by restoring T-type calcium current in fetuses during cholestasis

Science.gov (United States)

Adeyemi, Oladipupo; Alvarez-Laviada, Anita; Schultz, Francisca; Ibrahim, Effendi; Trauner, Michael; Williamson, Catherine; Glukhov, Alexey V.

2017-01-01

Background Increased maternal serum bile acid concentrations in intrahepatic cholestasis of pregnancy (ICP) are associated with fetal cardiac arrhythmias. Ursodeoxycholic acid (UDCA) has been shown to demonstrate anti-arrhythmic properties via preventing ICP-associated cardiac conduction slowing and development of reentrant arrhythmias, although the cellular mechanism is still being elucidated. Methods High-resolution fluorescent optical mapping of electrical activity and electrocardiogram measurements were used to characterize effects of UDCA on one-day-old neonatal and adult female Langendorff-perfused rat hearts. ICP was modelled by perfusion of taurocholic acid (TC, 400μM). Whole-cell calcium currents were recorded from neonatal rat and human fetal cardiomyocytes. Results TC significantly prolonged the PR interval by 11.0±3.5% (P<0.05) and slowed ventricular conduction velocity (CV) by 38.9±5.1% (P<0.05) exclusively in neonatal and not in maternal hearts. A similar CV decline was observed with the selective T-type calcium current (ICa,T) blocker mibefradil 1μM (23.0±6.2%, P<0.05), but not with the L-type calcium current (ICa,L) blocker nifedipine 1μM (6.9±6.6%, NS). The sodium channel blocker lidocaine (30μM) reduced CV by 60.4±4.5% (P<0.05). UDCA co-treatment was protective against CV slowing induced by TC and mibefradil, but not against lidocaine. UDCA prevented the TC-induced reduction in the ICa,T density in both isolated human fetal (−10.2±1.5 versus −5.5±0.9 pA/pF, P<0.05) and neonatal rat ventricular myocytes (−22.3±1.1 versus −9.6±0.8 pA/pF, P<0.0001), whereas UDCA had limited efficacy on the ICa,L. Conclusion Our findings demonstrate that ICa,T plays a significant role in ICP-associated fetal cardiac conduction slowing and arrhythmogenesis, and is an important component of the fetus-specific anti-arrhythmic activity of UDCA. PMID:28934223

Ursodeoxycholic acid prevents ventricular conduction slowing and arrhythmia by restoring T-type calcium current in fetuses during cholestasis.

Directory of Open Access Journals (Sweden)

Oladipupo Adeyemi

Full Text Available Increased maternal serum bile acid concentrations in intrahepatic cholestasis of pregnancy (ICP are associated with fetal cardiac arrhythmias. Ursodeoxycholic acid (UDCA has been shown to demonstrate anti-arrhythmic properties via preventing ICP-associated cardiac conduction slowing and development of reentrant arrhythmias, although the cellular mechanism is still being elucidated.High-resolution fluorescent optical mapping of electrical activity and electrocardiogram measurements were used to characterize effects of UDCA on one-day-old neonatal and adult female Langendorff-perfused rat hearts. ICP was modelled by perfusion of taurocholic acid (TC, 400μM. Whole-cell calcium currents were recorded from neonatal rat and human fetal cardiomyocytes.TC significantly prolonged the PR interval by 11.0±3.5% (P<0.05 and slowed ventricular conduction velocity (CV by 38.9±5.1% (P<0.05 exclusively in neonatal and not in maternal hearts. A similar CV decline was observed with the selective T-type calcium current (ICa,T blocker mibefradil 1μM (23.0±6.2%, P<0.05, but not with the L-type calcium current (ICa,L blocker nifedipine 1μM (6.9±6.6%, NS. The sodium channel blocker lidocaine (30μM reduced CV by 60.4±4.5% (P<0.05. UDCA co-treatment was protective against CV slowing induced by TC and mibefradil, but not against lidocaine. UDCA prevented the TC-induced reduction in the ICa,T density in both isolated human fetal (-10.2±1.5 versus -5.5±0.9 pA/pF, P<0.05 and neonatal rat ventricular myocytes (-22.3±1.1 versus -9.6±0.8 pA/pF, P<0.0001, whereas UDCA had limited efficacy on the ICa,L.Our findings demonstrate that ICa,T plays a significant role in ICP-associated fetal cardiac conduction slowing and arrhythmogenesis, and is an important component of the fetus-specific anti-arrhythmic activity of UDCA.

Rotor cage fault diagnosis in three-phase induction motors based on a current and virtual flux approach

International Nuclear Information System (INIS)

Pires, Dulce F.; Pires, V. Fernao; Martins, J.F.; Pires, A.J.

2009-01-01

This paper focuses on the detection of a rotor cage fault in a three-phase PWM feed induction motor. In inverter-fed machines there are some difficulties for the detection of a rotor cage fault. These difficulties are due to the fault signature that will be contained in the currents or voltages applied to the machine. In this way, a new approach based on the current and a virtual flux is proposed. The use of the virtual flux allows the improving of the signal to noise ratio. This approach also allows the identification of a rotor cage fault independently of the type of control used in the ac drive. The theoretical principle of this method is discussed. Simulation and experimental results are presented in order to show the effectiveness of the proposed approach

Fournier's gangrene current approaches.

Science.gov (United States)

Ozkan, Omer F; Koksal, Neset; Altinli, Ediz; Celik, Atilla; Uzun, Mehmet A; Cıkman, Oztekin; Akbas, Alpaslan; Ergun, Ersin; Kiraz, Hasan A; Karaayvaz, Muammer

2016-10-01

Fournier's gangrene is a rare but highly mortal infectious disease characterised by fulminant necrotising fasciitis involving the genital and perineal regions. The objective of this study is to analyse the demographics, clinical feature and treatment approaches as well as outcomes of Fournier's gangrene. Data were collected retrospectively from medical records and operative notes. Patient data were analysed by demographics, aetiological factors, clinical features, treatment approaches and outcomes. Twelve patients (five female and seven male) were enrolled in this study. The most common aetiology was perianal abscess (41·6%). Wound cultures showed a mixture of microorganisms in six (50%) patients. For faecal diversion, while colostomy was performed in six cases (50%), Flexi-Seal was used in two cases (16·6%). In four patients (33·4%), no faecal diversion was performed. Negative pressure wound therapy (NPWT) system was effective in the last four patients (33·4%). The mean hospitalisation period in patients who used NPWT was 18 days, while it was 20 days in the others. NPWT in Fournier's gangrene is a safe dressing method. It promotes granulation formation. Flexi-Seal faecal management is an alternative method to colostomy and provides protection from its associated complications. The combination of two devices (Flexi-Seal and NPWT) is an effective and comfortable method in the management of Fournier's gangrene in appropriate patients. © 2014 The Authors. International Wound Journal © 2014 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

An interdisciplinary review of current and future approaches to improving human-predator relations.

Science.gov (United States)

Pooley, S; Barua, M; Beinart, W; Dickman, A; Holmes, G; Lorimer, J; Loveridge, A J; Macdonald, D W; Marvin, G; Redpath, S; Sillero-Zubiri, C; Zimmermann, A; Milner-Gulland, E J

2017-06-01

In a world of shrinking habitats and increasing competition for natural resources, potentially dangerous predators bring the challenges of coexisting with wildlife sharply into focus. Through interdisciplinary collaboration among authors trained in the humanities, social sciences, and natural sciences, we reviewed current approaches to mitigating adverse human-predator encounters and devised a vision for future approaches to understanding and mitigating such encounters. Limitations to current approaches to mitigation include too much focus on negative impacts; oversimplified equating of levels of damage with levels of conflict; and unsuccessful technical fixes resulting from failure to engage locals, address hidden costs, or understand cultural (nonscientific) explanations of the causality of attacks. An emerging interdisciplinary literature suggests that to better frame and successfully mitigate negative human-predator relations conservation professionals need to consider dispensing with conflict as the dominant framework for thinking about human-predator encounters; work out what conflicts are really about (they may be human-human conflicts); unravel the historical contexts of particular conflicts; and explore different cultural ways of thinking about animals. The idea of cosmopolitan natures may help conservation professionals think more clearly about human-predator relations in both local and global context. These new perspectives for future research practice include a recommendation for focused interdisciplinary research and the use of new approaches, including human-animal geography, multispecies ethnography, and approaches from the environmental humanities notably environmental history. Managers should think carefully about how they engage with local cultural beliefs about wildlife, work with all parties to agree on what constitutes good evidence, develop processes and methods to mitigate conflicts, and decide how to monitor and evaluate these. Demand for

Acid distribution in phosphoric acid fuel cells

Energy Technology Data Exchange (ETDEWEB)

Okae, I.; Seya, A.; Umemoto, M. [Fuji Electric Co., Ltd., Chiba (Japan)

1996-12-31

Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

Moment approach to neoclassical flows, currents and transport in auxiliary heated tokamaks

International Nuclear Information System (INIS)

Kim, Yil Bong.

1988-02-01

The moment approach is utilized to derive the full complement of neoclassical transport processes in auxiliary heated tokamaks. The effects of auxiliary heating [neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH)] considered arise from the collisional interaction between the background plasma species and the fast-ion-tail species. From a known fast ion distribution function we evaluate the parallel (to the magnetic field) momentum and heat flow inputs to the background plasma. Then, through the momentum and heat flow balance equations, we can determine the induced parallel flows (and current) and radial transpot fluxes in ''equilibrium'' (on the time scale much longer than the collisional relaxation time, i.e., t >> 1ν/sub ii/). In addition to the fast-ion-induced current, the total neoclassical current includes the boostap current, which is driven by the pressure and temperature gradients, the Pfirsch-Schlueter current which is required for charge neutrality, and the neoclassical (including trapped particle effects) Spitzer current due to the parallel electric field. The radial transport fluxes also include off-diagonal compnents in the transport matrix which correspond to the Ware (neoclassical) pinch due to the inductive applied electric field an the fast-ion-induced radial fluxes, in addition to the usual pressure- and temperature-gradient-driven fluxes (particle diffusion and heat conduction). Once the tranport coefficient are completely determined, the radial fluxes and the heat fluxes can be substituted into the density and energy evolution equations to provide a complete description of ''equilibrium'' (δδt << ν/sub ii/) neoclassical transport processes in a plasma. 47 refs., 14 figs

Pharmacological modulations of cardiac ultra-rapid and slowly activating delayed rectifier currents: potential antiarrhythmic approaches.

Science.gov (United States)

Islam, Mohammed A

2010-01-01

Despite the emerging new insights into our understandings of the cellular mechanisms underlying cardiac arrhythmia, medical therapy for this disease remains unsatisfactory. Atrial fibrillation (AF), the most prevalent arrhythmia, is responsible for significant morbidity and mortality. On the other hand, ventricular fibrillation results in sudden cardiac deaths in many instances. Prolongation of cardiac action potential (AP) is a proven principle of antiarrhythmic therapy. Class III antiarrhythmic agents prolong AP and QT interval by blocking rapidly activating delayed rectifier current (I(Kr)). However, I(Kr) blocking drugs carry the risk of life-threatening proarrhythmia. Recently, modulation of atrial-selective ultra-rapid delayed rectifier current (I(Kur)), has emerged as a novel therapeutic approach to treat AF. A number of I(Kur) blockers are being evaluated for the treatment of AF. The inhibition of slowly activating delayed rectifier current (I(Ks)) has also been proposed as an effective and safer antiarrhythmic approach because of its distinguishing characteristics that differ in remarkable ways from other selective class III agents. Selective I(Ks) block may prolong AP duration (APD) at rapid rates without leading to proarrhythmia. This article reviews the pathophysiological roles of I(Kur) and I(Ks) in cardiac repolarization and the implications of newly developed I(Kur) and I(Ks) blocking agents as promising antiarrhythmic approaches. Several recent patents pertinent to antiarrhythmic drug development have been discussed. Further research will be required to evaluate the efficacy and safety of these agents in the clinical setting.

Co-administration of creatine and guanidinoacetic acid for augmented tissue bioenergetics: A novel approach?

Science.gov (United States)

Ostojic, Sergej M

2017-07-01

A confined absorption of exogenous creatine through creatine transporter (CRT1) seems to hamper its optimal uptake in bioenergetical deficits. Co-administration of guanidinoacetic acid (GAA) along with creatine could target other transport channels besides CRT1, and supremely improve cellular levels of creatine. This innovative approach might tackle tissues difficult to reach with conventional creatine interventions, providing a potentially more effective and safe mixture in clinical pharmacology and therapeutics. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Narcolepsy: current treatment options and future approaches

Science.gov (United States)

Billiard, Michel

2008-01-01

The management of narcolepsy is presently at a turning point. Three main avenues are considered in this review: 1) Two tendencies characterize the conventional treatment of narcolepsy. Modafinil has replaced methylphenidate and amphetamine as the first-line treatment of excessive daytime sleepiness (EDS) and sleep attacks, based on randomized, double blind, placebo-controlled clinical trials of modafinil, but on no direct comparison of modafinil versus traditional stimulants. For cataplexy, sleep paralysis, and hypnagogic hallucinations, new antidepressants tend to replace tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs) in spite of a lack of randomized, double blind, placebo-controlled clinical trials of these compounds; 2) The conventional treatment of narcolepsy is now challenged by sodium oxybate, the sodium salt of gammahydroxybutyrate, based on a series of randomized, double-blind, placebo-controlled clinical trials and a long-term open label study. This treatment has a fairly good efficacy and is active on all symptoms of narcolepsy. Careful titration up to an adequate level is essential both to obtain positive results and avoid adverse effects; 3) A series of new treatments are currently being tested, either in animal models or in humans, They include novel stimulant and anticataplectic drugs, endocrine therapy, and, more attractively, totally new approaches based on the present state of knowledge of the pathophysiology of narcolepsy with cataplexy, hypocretine-based therapies, and immunotherapy. PMID:18830438

Approaches to α-amino acids via rearrangement to electron-deficient nitrogen: Beckmann and Hofmann rearrangements of appropriate carboxyl-protected substrates

Directory of Open Access Journals (Sweden)

Sosale Chandrasekhar

2012-08-01

Full Text Available The titled approaches were effected with various 2-substituted benzoylacetic acid oximes 3 (Beckmann and 2-substituted malonamic acids 9 (Hofmann, their carboxyl groups being masked as a 2,4,10-trioxaadamantane unit (an orthoacetate. The oxime mesylates have been rearranged with basic Al2O3 in refluxing CHCl3, and the malonamic acids with phenyliodoso acetate and KOH/MeOH. Both routes are characterized by excellent overall yields. Structure confirmation of final products was conducted with X-ray diffraction in selected cases. The final N-benzoyl and N-(methoxycarbonyl products are α-amino acids with both carboxyl and amino protection; hence, they are of great interest in peptide synthesis.

Are Current Accounts of Asian Economies Mean-reverting?: Nonlinear Unit Root Test Approach

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Bonghan Kim

2005-12-01

Full Text Available This paper tests the mean reverting property of current account in the financial crisis-affected 5 counties of southeast Asia using nonlinear unit root tests of Park and shintani(2004. Our approach is based on the idea that a conventional unit root test has lower power in detecting the nonlinear mean reverting behavior if the current account follows a nonlinear mean reversion process. We obtained following empirical results. First, for the pre-crisis period (1981Q1-1996Q4, the current accounts of Indonesia, Malaysia and Philippines are mean-reverting but those of Korea and Thailand are not mean-reverting. Second, for the full sample period (1981Q1-2003Q4, the ADF test fails to reject the unit root of the current account in all countries except Philippines. However, unit root is rejected in favor of nonlinear mean reversion except Thailand. This nonlinear unit root test result implies that crisis-affected Asian countries except Thailand have sustainable paths of current accounts. Third, when the current accounts of East Asian countries are nonlinear mean-reverting, the mean reverting process can be well described by the ESTAR model, instead of the DTAR or DLSTAR model. The nonlinear unit root test results imply smooth nonlinear mean-reversion behaviors of East Asian current accounts. Finally, the shape of estimated impulse response functions becomes steeper as the size of shock increases, which is the very characteristic of the nonlinear process.

POROUS ALUMINOPHOSPHATES :From Molecular Sieves to Designed Acid Catalysts

Science.gov (United States)

Pastore, H. O.; Coluccia, S.; Marchese, L.

2005-08-01

This review covers the synthesis, characterization, and physico-chemical properties of microporous and mesoporous aluminophosphates and silicoaluminophosphates molecular sieves. Particular emphasis is given to the materials that have found applications as acid catalysts. We consider the evolution of the synthesis procedures from the first discoveries to the current methodologies and give perspectives for new possible synthesis strategies. Emphasis is given to the use of specially prepared precursors/reactants designed for the use as molecular sieves. Experimental (especially MAS-NMR and FTIR spectroscopy) and theoretical approaches to the description of the Si insertion into the ALPO framework and to the acidic properties of SAPOs and MeAPSOs materials are discussed.

Simultaneous improvement in production of microalgal biodiesel and high-value alpha-linolenic acid by a single regulator acetylcholine.

Science.gov (United States)

Parsaeimehr, Ali; Sun, Zhilan; Dou, Xiao; Chen, Yi-Feng

2015-01-01

Photoautotrophic microalgae are a promising avenue for sustained biodiesel production, but are compromised by low yields of biomass and lipids at present. We are developing a chemical approach to improve microalgal accumulation of feedstock lipids as well as high-value alpha-linolenic acid which in turn might provide a driving force for biodiesel production. We demonstrate the effectiveness of the small bioactive molecule "acetylcholine" on accumulation of biomass, total lipids, and alpha-linolenic acid in Chlorella sorokiniana. The effectiveness exists in different species of Chlorella. Moreover, the precursor and analogs of acetylcholine display increased effectiveness at higher applied doses, with maximal increases by 126, 80, and 60% over controls for biomass, total lipids, and alpha-linolenic acid, respectively. Production of calculated biodiesel was also improved by the precursor and analogs of acetylcholine. The biodiesel quality affected by changes in microalgal fatty acid composition was addressed. The chemical approach described here could improve the lipid yield and biodiesel production of photoautotrophic microalgae if combined with current genetic approaches.

Synthesis of nucleotide–amino acid conjugates designed for photo-CIDNP experiments by a phosphotriester approach

Directory of Open Access Journals (Sweden)

Tatyana V. Abramova

2013-12-01

Full Text Available Conjugates of 2’-deoxyguanosine, L-tryptophan and benzophenone designed to study pathways of fast radical reactions by the photo Chemically Induced Dynamic Nuclear Polarization (photo-CIDNP method were obtained by the phosphotriester block liquid phase synthesis. The phosphotriester approach to the oligonucleotide synthesis was shown to be a versatile and economic strategy for preparing the required amount of high quality samples of nucleotide–amino acid conjugates.

Omics-based approaches reveal phospholipids remodeling of Rhizopus oryzae responding to furfural stress for fumaric acid-production from xylose.

Science.gov (United States)

Pan, Xinrong; Liu, Huanhuan; Liu, Jiao; Wang, Cheng; Wen, Jianping

2016-12-01

In order to relieve the toxicity of furfural on Rhizopus oryzae fermentation, the molecular mechanism of R. oryzae responding to furfural stress for fumaric acid-production was investigated by omics-based approaches. In metabolomics analysis, 29 metabolites including amino acid, sugars, polyols and fatty acids showed significant changes for maintaining the basic cell metabolism at the cost of lowering fumaric acid production. To further uncover the survival mechanism, lipidomics was carried out, revealing that phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol and polyunsaturated acyl chains might be closely correlated with R. oryzae's adapting to furfural stress. Based on the above omics analysis, lecithin, inositol and soybean oil were exogenously supplemented separately with an optimized concentration in the presence of furfural, which increased fumaric acid titer from 5.78g/L to 10.03g/L, 10.05g/L and 12.13g/L (increased by 73.5%, 73.8% and 110%, respectively). These findings provide a methodological guidance for hemicellulose-fumaric acid development. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modeling molecular acidity with electronic properties and Hammett constants for substituted benzoic acids.

Science.gov (United States)

Huang, Ying; Liu, Lianghong; Liu, Wanhui; Liu, Shaogang; Liu, Shubin

2011-12-29

Molecular acidity is an important physiochemical property essential in many fields of molecular studies, but an efficient and reliable computational approach to make accurate predictions is still missing. In this work, based on our previous studies to use gas phase electronic properties such as molecular electrostatic potential and valence natural atomic orbitals of the acidic atom and leaving proton, we demonstrate here that different approaches can be employed to tackle this problem. To that end, we employ 196 singly, doubly, and triply substituted benzoic acids for the study. We show that two different approaches are possible, one focusing on the carboxyl group through its localized electronic properties and the other on the substituting groups via Hammett constants and their additivity rule. Our present results clearly exhibit that with the linear models built from the singly substituted species, one can accurately predict the pK(a) values for the doubly and triply substituted species with both of these two approaches. The predictions from these approaches are consistent with each other and agree well with the experimental data. These intrinsically different approaches are the two manifestations of the same molecular acidity property, both valid and complementary to each other. © 2011 American Chemical Society

Simple engineering design for complex thermoelectric generators based on reduced current approach

DEFF Research Database (Denmark)

Wijesooriyage, Waruna Dissanayaka; Rezaniakolaei, Alireza; Rosendahl, Lasse

2015-01-01

Thermoelectric generators (TEGs) are niche candidate for the field of energy management as electrical generator devices. Generally, comprehensive and accurate design techniques for TEGs (thermoelectric generators), such as reduced current approach (RCA), are complex and time consuming processes....... This study develops a simple, comprehensive and accurate TEG designing technique based on RCA. The proposed method can predict the most efficient TEG architecture with more than 97% accuracy comparing to the RCA over wide range of possible temperature and zT for present TEG applications. Moreover...

A computational fluid dynamics approach to nucleation in the water-sulfuric acid system.

Science.gov (United States)

Herrmann, E; Brus, D; Hyvärinen, A-P; Stratmann, F; Wilck, M; Lihavainen, H; Kulmala, M

2010-08-12

This study presents a computational fluid dynamics modeling approach to investigate the nucleation in the water-sulfuric acid system in a flow tube. On the basis of an existing experimental setup (Brus, D.; Hyvärinen, A.-P.; Viisanen, Y.; Kulmala, M.; Lihavainen, H. Atmos. Chem. Phys. 2010, 10, 2631-2641), we first establish the effect of convection on the flow profile. We then proceed to simulate nucleation for relative humidities of 10, 30, and 50% and for sulfuric acid concentration between 10(9) to 3 x 10(10) cm(-3). We describe the nucleation zone in detail and determine how flow rate and relative humidity affect its characteristics. Experimental nucleation rates are compared to rates gained from classical binary and kinetic nucleation theory as well as cluster activation theory. For low RH values, kinetic theory yields the best agreement with experimental results while binary nucleation best reproduces the experimental nucleation behavior at 50% relative humidity. Particle growth is modeled for an example case at 50% relative humidity. The final simulated diameter is very close to the experimental result.

Current Techniques for the Cultivation of Ganoderma lucidum for the Production of Biomass, Ganoderic Acid and Polysaccharides

Directory of Open Access Journals (Sweden)

Ricardo Wagner

2003-01-01

Full Text Available Ganoderma lucidum is a medicinal mushroom that has been used in the Orient for more than 2000 years. Due to the long time required for basidiocarp formation, attention has recently been given to the use of submerged fermentation for the production of mycelial biomass and its bioactive components, such as polysaccharides and ganoderic acids. We review the current state of knowledge about the cultivation of G. lucidum by modern fermentation techniques, focussing on the effects of fermentation conditions and how knowledge of these effects has been used to develop strategies for improving the production of biomass, polysaccharides and ganoderic acid. We also outline the methods that have been used for biomass and product recovery and point out potential problems involved in these steps. Studies to date have been almost entirely limited to laboratory scale and much more understanding of the physiology of G. lucidum and its relationship with growth morphology will be necessary before it will be possible to develop economical large scale processes.

Particle currents in a space-time dependent and CP-violating Higgs background: a field theory approach

International Nuclear Information System (INIS)

Comelli, D.; Riotto, A.

1995-06-01

Motivated by cosmological applications like electroweak baryogenesis, we develop a field theoretic approach to the computation of particle currents on a space-time dependent and CP-violating Higgs background. We consider the Standard Model model with two Higgs doublets and CP violation in the scalar sector, and compute both fermionic and Higgs currents by means of an expansion in the background fields. We discuss the gauge dependence of the results and the renormalization of the current operators, showing that in the limit of local equilibrium, no extra renormalization conditions are needed in order to specify the system completely. (orig.)

Fatty acid is a potential agent for bone tissue induction: In vitro and in vivo approach.

Science.gov (United States)

Cardoso, Guinea Bc; Chacon, Erivelto; Chacon, Priscila Gl; Bordeaux-Rego, Pedro; Duarte, Adriana Ss; Saad, Sara T Olalla; Zavaglia, Cecilia Ac; Cunha, Marcelo R

2017-12-01

Our hypothesis was to investigate the fatty acid potential as a bone induction factor. In vitro and in vivo studies were performed to evaluate this approach. Oleic acid was used in a 0.5 wt.% concentration. Polycaprolactone was used as the polymeric matrix by combining solvent-casting and particulate-leaching techniques, with a final porosity of 70 wt.%, investigated by SEM images. Contact angle measurements were produced to investigate the influence of oleic acid on polycaprolactone chains. Cell culture was performed using adipocyte-derived stem cells to evaluate biocompatibility and bioactivity properties. In addition, in vivo studies were performed to evaluate the induction potential of oleic acid addition. Adipocyte-derived stem cells were used to provide differentiation after 21 days of culture. Likewise, information were obtained with in vivo data and cellular invagination was observed on both scaffolds (polycaprolactone and polycaprolactone /oleic acid); interestingly, the scaffold with oleic acid addition demonstrated that cellular migrations are not related to the surrounding tissue, indicating bioactive potential. Our hypothesis is that fatty acid may be used as a potential induction factor for bone tissue engineering. The study's findings indicate oleic acid as a possible agent for bone induction, according to data on cell differentiation, proliferation, and migration. Impact statement The biomaterial combined in this study on bone regeneration is innovative and shows promising results in the treatment of bone lesions. Polycaprolactone (PCL) and oleic acid have been studied separately. In this research, we combined biomaterials to assess the stimulus and the speed of bone healing.

Role of nitrous acid during the dissolution of UO2 in nitric acid

International Nuclear Information System (INIS)

Deigan, N.; Pandey, N.K.; Kamachi Mudali, U.; Joshi, J.B.

2016-01-01

Understanding the dissolution behaviour of sintered UO 2 pellet in nitric acid is very important in designing an industrial scale dissolution system for the plutonium rich fast reactor MOX fuel. In the current article we have established the role of nitrous acid on the dissolution kinetics of UO 2 pellets in nitric acid. Under the chemical conditions that prevail in a typical Purex process, NO and NO 2 gases gets generated in the process streams. These gases produce nitrous acid in nitric acid medium. In addition, during the dissolution of UO 2 in nitric acid medium, nitrous acid is further produced in-situ at the pellet solution interface. As uranium dissolves oxidatively in nitric acid medium wherein it goes from U(IV) in solid to U(VI) in liquid, presence of nitrous acid (a good oxidizing agent) accelerates the reaction rate. Hence for determining the reaction mechanism of UO 2 dissolution in nitric acid medium, knowing the nitrous acid concentration profile during the course of dissolution is important. The current work involves the measurement of nitrous acid concentration during the course of dissolution of sintered UO 2 pellets in 8M starting nitric acid concentration as a function of mixing intensity from unstirred condition to 1500 RPM

The effect of sulfuric acid on pore initiation in anodic alumina formed in oxalic acid

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Behnam Hafezi

2014-07-01

Full Text Available In this work, a tracer study on pore initiation in anodic alumina in oxalic acid was performed. Effects of some experimental parameters such as applied electrical potential, electrolyte composition and heat pretreatment were evaluated. Electrochemical and morphological experiments were performed using potentiostatic anodizing and scanning electron microscopy (SEM techniques, respectively. Effect of electrolyte composition on current density was discussed. In various electrical potentials, electrolyte composition had different effects on current density. Addition of sulfuric acid into oxalic acid increased porosity. Also, distribution of pore size and pore diameter were influenced by presence of sulfuric acid. Effect of electrolyte composition on the morphology of aluminum surface layer depended on the electric potential. Current density and porosity of aluminum surface layer was decreased by heat pretreatment.

Metabolic Engineering of Yeast to Produce Fatty Acid-derived Biofuels: Bottlenecks and Solutions

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Jiayuan eSheng

2015-06-01

Full Text Available Fatty acid-derived biofuels can be a better solution than bioethanol to replace petroleum fuel, since they have similar energy content and combustion properties as current transportation fuels. The environmentally friendly microbial fermentation process has been used to synthesize advanced biofuels from renewable feedstock. Due to their robustness as well as the high tolerance to fermentation inhibitors and phage contamination, yeast strains such as Saccharomyces cerevisiae and Yarrowia lipolytica have attracted tremendous attention in recent studies regarding the production of fatty acid-derived biofuels, including fatty acids, fatty acid ethyl esters, fatty alcohols, and fatty alkanes. However, the native yeast strains cannot produce fatty acids and fatty acid-derived biofuels in large quantities. To this end, we have summarized recent publications in this review on metabolic engineering of yeast strains to improve the production of fatty acid-derived biofuels, identified the bottlenecks that limit the productivity of biofuels, and categorized the appropriate approaches to overcome these obstacles.

Exhaustive and stable electromembrane extraction of acidic drugs from human plasma

DEFF Research Database (Denmark)

Huang, Chuixiu; Gjelstad, Astrid; Seip, Knut Fredrik

2015-01-01

The first part of the current work systematically described the screening of different types of organic solvents as the supported liquid membrane (SLM) for electromembrane extraction (EME) of acidic drugs, including different alcohols, ketones, and ethers. Seven acidic drugs with a wide logP rang......). With this SLM, exhaustive EME was performed from diluted human plasma, and the recoveries of five out of seven analytes were over 91% after 10min EME. This approach was evaluated using HPLC-UV, and the evaluation data were found to be satisfactory...... to increasing viscosity and decreasing α and π* values. The system-current during EME was found to be dependent on the type and the volume of the SLM. In contact with human plasma, an SLM of pure 1-heptanol was unstable, and to improve stability, 1-heptanol was mixed with 2-nitrophenyl octyl ether (NPOE...

Angular approach combined to mechanical model for tool breakage detection by eddy current sensors

Science.gov (United States)

Ritou, M.; Garnier, S.; Furet, B.; Hascoet, J. Y.

2014-02-01

The paper presents a new complete approach for Tool Condition Monitoring (TCM) in milling. The aim is the early detection of small damages so that catastrophic tool failures are prevented. A versatile in-process monitoring system is introduced for reliability concerns. The tool condition is determined by estimates of the radial eccentricity of the teeth. An adequate criterion is proposed combining mechanical model of milling and angular approach.Then, a new solution is proposed for the estimate of cutting force using eddy current sensors implemented close to spindle nose. Signals are analysed in the angular domain, notably by synchronous averaging technique. Phase shifts induced by changes of machining direction are compensated. Results are compared with cutting forces measured with a dynamometer table.The proposed method is implemented in an industrial case of pocket machining operation. One of the cutting edges has been slightly damaged during the machining, as shown by a direct measurement of the tool. A control chart is established with the estimates of cutter eccentricity obtained during the machining from the eddy current sensors signals. Efficiency and reliability of the method is demonstrated by a successful detection of the damage.

The Stewart Approach – One Clinician’s Perspective

Science.gov (United States)

Morgan, T John

2009-01-01

Peter Stewart added controversy to an already troubled subject when he entered the clinical acid-base arena. His approach puts water dissociation at the centre of the acid-base status of body fluids. It is based on six simultaneous equations, incorporating the Laws of Mass Action, Mass Conservation, and Electrical Neutrality. Together with Gibbs-Donnan equilibria, these equations explain the diagnostically important PaCO2/pH relationship, and improve understanding of the physiologic basis of traditional acid-base approaches. Spin-offs have included new scanning tools for unmeasured ions, in particular the ‘strong ion gap’ and ‘net unmeasured ions’. The most controversial feature is the designation of pH and bicarbonate concentrations as dependent variables, answerable exclusively to three independent variables. These are the strong ion difference (SID), the total concentration of non-volatile weak acid (ATOT), and PCO2. Aspects of this assertion conflict with traditional renal physiology, and with current models of membrane H+/base transporters, oxidative phosphorylation, and proton and bicarbonate ionophores. The debate in this area is ongoing. Meanwhile, Stewart-style diagnostic and decision support systems such as the ‘Strong Ion Calculator’ and the web-site www.acidbase.org are now appearing. PMID:19565024

Converting Eucalyptus biomass into ethanol: Financial and sensitivity analysis in a co-current dilute acid process. Part II

International Nuclear Information System (INIS)

Gonzalez, R.; Treasure, T.; Phillips, R.; Jameel, H.; Saloni, D.; Wright, J.; Abt, R.

2011-01-01

The technical and financial performance of high yield Eucalyptus biomass in a co-current dilute acid pretreatment followed by enzymatic hydrolysis process was simulated using WinGEMS registered and Excel registered . Average ethanol yield per dry Mg of Eucalyptus biomass was approximately 347.6 L of ethanol (with average carbohydrate content in the biomass around 66.1%) at a cost of 0.49 L -1 of ethanol, cash cost of ∝0.46 L -1 and CAPEX of 1.03 L -1 of ethanol. The main cost drivers are: biomass, enzyme, tax, fuel (gasoline), depreciation and labor. Profitability of the process is very sensitive to biomass cost, carbohydrate content (%) in biomass and enzyme cost. Biomass delivered cost was simulated and financially evaluated in Part I; here in Part II the conversion of this raw material into cellulosic ethanol using the dilute acid process is evaluated. (author)

Limitations Of The Current State Space Modelling Approach In Multistage Machining Processes Due To Operation Variations

Science.gov (United States)

Abellán-Nebot, J. V.; Liu, J.; Romero, F.

2009-11-01

The State Space modelling approach has been recently proposed as an engineering-driven technique for part quality prediction in Multistage Machining Processes (MMP). Current State Space models incorporate fixture and datum variations in the multi-stage variation propagation, without explicitly considering common operation variations such as machine-tool thermal distortions, cutting-tool wear, cutting-tool deflections, etc. This paper shows the limitations of the current State Space model through an experimental case study where the effect of the spindle thermal expansion, cutting-tool flank wear and locator errors are introduced. The paper also discusses the extension of the current State Space model to include operation variations and its potential benefits.

Specificity of the Acute Tryptophan and Tyrosine Plus Phenylalanine Depletion and Loading Tests I. Review of Biochemical Aspects and Poor Specificity of Current Amino Acid Formulations

Directory of Open Access Journals (Sweden)

Abdulla A.-B. Badawy

2010-06-01

Full Text Available The acute tryptophan or tyrosine plus phenylalanine depletion and loading tests are powerful tools for studying the roles of serotonin, dopamine and noradrenaline in normal subjects and those with behavioural disorders. The current amino acid formulations for these tests, however, are associated with undesirable decreases in ratios of tryptophan or tyrosine plus phenylalanine to competing amino acids resulting in loss of specificity. This could confound biochemical and behavioural findings. Compositions of current formulations are reviewed, the biochemical principles underpinning the tests are revisited and examples of unintended changes in the above ratios and their impact on monoamine function and behaviour will be demonstrated from data in the literature. The presence of excessive amounts of the 3 branched-chain amino acids Leu, Ile and Val is responsible for these unintended decreases and the consequent loss of specificity. Strategies for enhancing the specificity of the different formulations are proposed.

Specificity of the Acute Tryptophan and Tyrosine plus Phenylalanine Depletion and Loading Tests I. Review of Biochemical Aspects and Poor Specificity of Current Amino Acid Formulations

Directory of Open Access Journals (Sweden)

Abdulla A.-B. Badawy

2010-01-01

Full Text Available The acute tryptophan or tyrosine plus phenylalanine depletion and loading tests are powerful tools for studying the roles of serotonin, dopamine and noradrenaline in normal subjects and those with behavioural disorders. The current amino acid formulations for these tests, however, are associated with undesirable decreases in ratios of tryptophan or tyrosine plus phenylalanine to competing amino acids resulting in loss of specificity. This could confound biochemical and behavioural findings. Compositions of current formulations are reviewed, the biochemical principles underpinning the tests are revisited and examples of unintended changes in the above ratios and their impact on monoamine function and behaviour will be demonstrated from data in the literature. The presence of excessive amounts of the 3 branched-chain amino acids Leu, Ile and Val is responsible for these unintended decreases and the consequent loss of specificity. Strategies for enhancing the specificity of the different formulations are proposed.

Narcolepsy: current treatment options and future approaches

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Michel Billiard

2008-06-01

Full Text Available Michel BilliardDepartment of Neurology, Gui de Chauliac Hospital, Montpellier, FranceAbstract: The management of narcolepsy is presently at a turning point. Three main avenues are considered in this review: 1 Two tendencies characterize the conventional treatment of narcolepsy. Modafinil has replaced methylphenidate and amphetamine as the first-line treatment of excessive daytime sleepiness (EDS and sleep attacks, based on randomized, double blind, placebo-controlled clinical trials of modafinil, but on no direct comparison of modafinil versus traditional stimulants. For cataplexy, sleep paralysis, and hypnagogic hallucinations, new antidepressants tend to replace tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs in spite of a lack of randomized, double blind, placebo-controlled clinical trials of these compounds; 2 The conventional treatment of narcolepsy is now challenged by sodium oxybate, the sodium salt of gammahydroxybutyrate, based on a series of randomized, double-blind, placebo-controlled clinical trials and a long-term open label study. This treatment has a fairly good efficacy and is active on all symptoms of narcolepsy. Careful titration up to an adequate level is essential both to obtain positive results and avoid adverse effects; 3 A series of new treatments are currently being tested, either in animal models or in humans, They include novel stimulant and anticataplectic drugs, endocrine therapy, and, more attractively, totally new approaches based on the present state of knowledge of the pathophysiology of narcolepsy with cataplexy, hypocretine-based therapies, and immunotherapy.Keywords: narcolepsy, treatment, conventional drugs, modafinil, sodium oxybate, future treatments

Dimerization of Carboxylic Acids: An Equation of State Approach

DEFF Research Database (Denmark)

Tsivintzelis, Ioannis; Kontogeorgis, Georgios; Panayiotou, Costas

2017-01-01

The association term of the nonrandom hydrogen bonding theory, which is an equation of state model, is extended to describe the dimerization of carboxylic acids in binary mixtures with inert solvents and in systems of two different acids. Subsequently, the model is applied to describe the excess...

Current approaches to assessing intangible assets

OpenAIRE

Урусова, Зінаїда Петрівна

2013-01-01

The article analyzes methods of assessing intangible assets in Ukraine as well as in accordance with International Financial Reporting Standards. Contemporary approaches to assessing intangible assets have been researched.

Electrolysis of an acidic NaCl solution with a graphite anode : IV. Chlorine evolution at a graphite electrode after switching off current

NARCIS (Netherlands)

Janssen, L.J.J.; Hoogland, J.G.

1970-01-01

During electrolysis of an acid chloride soln., at. Cl is taken up by a graphite anode. After switching off the current, the evolution of mol. Cl continues. This phenomenon is designated as residual gas evolution (RGE). The mol. Cl is formed according to the Volmer-Heyrovsky mechanism, Clads + e ->

Graphene-Based Nanomaterials as Heterogeneous Acid Catalysts: A Comprehensive Perspective

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Bhaskar Garg

2014-09-01

Full Text Available Acid catalysis is quite prevalent and probably one of the most routine operations in both industrial processes and research laboratories worldwide. Recently, “graphene”, a two dimensional single-layer carbon sheet with hexagonal packed lattice structure, imitative of nanomaterials, has shown great potential as alternative and eco-friendly solid carbocatalyst for a variety of acid-catalyzed reactions. Owing to their exceptional physical, chemical, and mechanical properties, graphene-based nanomaterials (G-NMs offer highly stable Brønsted acidic sites, high mass transfer, relatively large surface areas, water tolerant character, and convenient recoverability as well as recyclability, whilst retaining high activity in acid-catalyzed chemical reactions. This comprehensive review focuses on the chemistry of G-NMs, including their synthesis, characterization, properties, functionalization, and up-to-date applications in heterogeneous acid catalysis. In line with this, in certain instances readers may find herein some criticisms that should be taken as constructive and would be of value in understanding the scope and limitations of current approaches utilizing graphene and its derivatives for the same.

Weight-of-evidence approach in assessment of ecotoxicological risks of acid sulphate soils in the Baltic Sea river estuaries

Energy Technology Data Exchange (ETDEWEB)

Wallin, Jaana, E-mail: jaana.wallin@jyu.fi [Finnish Environment Institute SYKE, Survontie 9 A, FI-40500 Jyväskylä (Finland); Karjalainen, Anna K. [Finnish Environment Institute SYKE, Survontie 9 A, FI-40500 Jyväskylä (Finland); Schultz, Eija [Finnish Environment Institute SYKE, Hakuninmaantie 6, FI-00430 Helsinki (Finland); Järvistö, Johanna; Leppänen, Matti; Vuori, Kari-Matti [Finnish Environment Institute SYKE, Survontie 9 A, FI-40500 Jyväskylä (Finland)

2015-03-01

Acidity and leaching of metals from acid sulphate soils (ASSs) impair the water quality of receiving surface waters. The largest ASS areas in Europe are found in the coasts of the northern Baltic Sea. We used weight-of-evidence (WoE) approach to assess potential risks in 14 estuary sites affected by ASS in the Gulf of Finland, northern Baltic Sea. The assessment was based on exposure and effect profiles utilizing sediment and water metal concentrations and concurrent pH variation, sediment toxicity tests using the luminescent bacterium Vibrio fischeri and the midge Chironomus riparius, and the ecological status of benthic macroinvertebrate communities. Sediment metal concentrations were compared to national sediment quality criteria/guidelines, and water metal concentrations to environmental quality standards (EQSs). Hazard quotients (HQs) were established for maximum aluminium, cadmium and zinc concentrations at low pH based on applicable US EPA toxicity database. Sediment metal concentrations were clearly elevated in most of the studied estuaries. The EQS of cadmium (0.1 μg/l) was exceeded in 3 estuaries out of 14. The pH-minima were below the national threshold value (5.5) between good and satisfactory water quality in 10 estuaries. V. fischeri bioluminescence indicated toxicity of the sediments but toxic response was not observed in the C. riparius emergence test. Benthic invertebrate communities were deteriorated in 6 out of 14 sites based on the benthic invertebrate quality index. The overall ecotoxicological risk was assessed as low in five, moderate in three and high in five of the estuary sites. The risk assessment utilizing the WoE approach indicated that harmful effects of ASSs are likely to occur in the Baltic Sea river estuaries located at the ASS hotspot area. - Highlights: • Acid sulphate soils release high amounts of metals and acidity. • Metals and acidity are transported to estuary sites. • Acid sulphate soils impair the ecological status

Auroral Substorms: Search for Processes Causing the Expansion Phase in Terms of the Electric Current Approach

Science.gov (United States)

Akasofu, Syun-Ichi

2017-10-01

Auroral substorms are mostly manifestations of dissipative processes of electromagnetic energy. Thus, we consider a sequence of processes consisting of the power supply (dynamo), transmission (currents/circuits) and dissipations (auroral substorms-the end product), namely the electric current line approach. This work confirms quantitatively that after accumulating magnetic energy during the growth phase, the magnetosphere unloads the stored magnetic energy impulsively in order to stabilize itself. This work is based on our result that substorms are caused by two current systems, the directly driven (DD) current system and the unloading system (UL). The most crucial finding in this work is the identification of the UL (unloading) current system which is responsible for the expansion phase. A very tentative sequence of the processes leading to the expansion phase (the generation of the UL current system) is suggested for future discussions. (1) The solar wind-magnetosphere dynamo enhances significantly the plasma sheet current when its power is increased above 10^{18} erg/s (10^{11} w). (2) The magnetosphere accumulates magnetic energy during the growth phase, because the ionosphere cannot dissipate the increasing power because of a low conductivity. As a result, the magnetosphere is inflated, accumulating magnetic energy. (3) When the power reaches 3-5× 10^{18} erg/s (3-5× 10^{11} w) for about one hour and the stored magnetic energy reaches 3-5×10^{22} ergs (10^{15} J), the magnetosphere begins to develop perturbations caused by current instabilities (the current density {≈}3× 10^{-12} A/cm2 and the total current {≈}106 A at 6 Re). As a result, the plasma sheet current is reduced. (4) The magnetosphere is thus deflated. The current reduction causes partial B/partial t > 0 in the main body of the magnetosphere, producing an earthward electric field. As it is transmitted to the ionosphere, it becomes equatorward-directed electric field which drives both

Current approaches to enhance CNS delivery of drugs across the brain barriers

Directory of Open Access Journals (Sweden)

Lu CT

2014-05-01

Full Text Available Cui-Tao Lu,1 Ying-Zheng Zhao,2,3 Ho Lun Wong,4 Jun Cai,5 Lei Peng,2 Xin-Qiao Tian1 1The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou City, Zhejiang Province, People’s Republic of China; 2Hainan Medical College, Haikou City, Hainan Province, People’s Republic of China; 3College of Pharmaceutical Sciences, Wenzhou Medical University, Zhejiang Province, People’s Republic of China; 4School of Pharmacy, Temple University, Philadelphia, PA, USA; 5Departments of Pediatrics and Anatomical Sciences and Neurobiology, University of Louisville School of Medicine Louisville, KY, USA Abstract: Although many agents have therapeutic potentials for central nervous system (CNS diseases, few of these agents have been clinically used because of the brain barriers. As the protective barrier of the CNS, the blood–brain barrier and the blood–cerebrospinal fluid barrier maintain the brain microenvironment, neuronal activity, and proper functioning of the CNS. Different strategies for efficient CNS delivery have been studied. This article reviews the current approaches to open or facilitate penetration across these barriers for enhanced drug delivery to the CNS. These approaches are summarized into three broad categories: noninvasive, invasive, and miscellaneous techniques. The progresses made using these approaches are reviewed, and the associated mechanisms and problems are discussed. Keywords: drug delivery system, blood–brain barrier (BBB, central nervous system, brain-targeted therapy, cerebrospinal fluid (CSF

Modelling geomagnetically induced currents in midlatitude Central Europe using a thin-sheet approach

Science.gov (United States)

Bailey, Rachel L.; Halbedl, Thomas S.; Schattauer, Ingrid; Römer, Alexander; Achleitner, Georg; Beggan, Ciaran D.; Wesztergom, Viktor; Egli, Ramon; Leonhardt, Roman

2017-06-01

Geomagnetically induced currents (GICs) in power systems, which can lead to transformer damage over the short and the long term, are a result of space weather events and geomagnetic variations. For a long time, only high-latitude areas were considered to be at risk from these currents, but recent studies show that considerable GICs also appear in midlatitude and equatorial countries. In this paper, we present initial results from a GIC model using a thin-sheet approach with detailed surface and subsurface conductivity models to compute the induced geoelectric field. The results are compared to measurements of direct currents in a transformer neutral and show very good agreement for short-period variations such as geomagnetic storms. Long-period signals such as quiet-day diurnal variations are not represented accurately, and we examine the cause of this misfit. The modelling of GICs from regionally varying geoelectric fields is discussed and shown to be an important factor contributing to overall model accuracy. We demonstrate that the Austrian power grid is susceptible to large GICs in the range of tens of amperes, particularly from strong geomagnetic variations in the east-west direction.

Production of phenylpyruvic acid from L-phenylalanine using an L-amino acid deaminase from Proteus mirabilis: comparison of enzymatic and whole-cell biotransformation approaches.

Science.gov (United States)

Hou, Ying; Hossain, Gazi Sakir; Li, Jianghua; Shin, Hyun-Dong; Liu, Long; Du, Guocheng

2015-10-01

Phenylpyruvic acid (PPA) is an important organic acid that has a wide range of applications. In this study, the membrane-bound L-amino acid deaminase (L-AAD) gene from Proteus mirabilis KCTC 2566 was expressed in Escherichia coli BL21(DE3) and then the L-AAD was purified. After that, we used the purified enzyme and the recombinant E. coli whole-cell biocatalyst to produce PPA via a one-step biotransformation from L-phenylalanine. L-AAD was solubilized from the membrane and purified 52-fold with an overall yield of 13 %, which corresponded to a specific activity of 0.94 ± 0.01 μmol PPA min(-1)·mg(-1). Then, the biotransformation conditions for the pure enzyme and the whole-cell biocatalyst were optimized. The maximal production was 2.6 ± 0.1 g·L(-1) (specific activity of 1.02 ± 0.02 μmol PPA min(-1)·mg(-1) protein, 86.7 ± 5 % mass conversion rate, and 1.04 g·L(-1)·h(-1) productivity) and 3.3 ± 0.2 g L(-1) (specific activity of 0.013 ± 0.003 μmol PPA min(-1)·mg(-1) protein, 82.5 ± 4 % mass conversion rate, and 0.55 g·L(-1)·h(-1) productivity) for the pure enzyme and whole-cell biocatalyst, respectively. Comparative studies of the enzymatic and whole-cell biotransformation were performed in terms of specific activity, production, conversion, productivity, stability, need of external cofactors, and recycling. We have developed two eco-friendly and efficient approaches for PPA production. The strategy described herein may aid the biotransformational synthesis of other α-keto acids from their corresponding amino acids.

Targeting Pancreatic Ductal Adenocarcinoma Acidic Microenvironment

Science.gov (United States)

Cruz-Monserrate, Zobeida; Roland, Christina L.; Deng, Defeng; Arumugam, Thiruvengadam; Moshnikova, Anna; Andreev, Oleg A.; Reshetnyak, Yana K.; Logsdon, Craig D.

2014-03-01

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death in the USA, accounting for ~40,000 deaths annually. The dismal prognosis for PDAC is largely due to its late diagnosis. Currently, the most sensitive diagnosis of PDAC requires invasive procedures, such as endoscopic ultrasonography, which has inherent risks and accuracy that is highly operator dependent. Here we took advantage of a general characteristic of solid tumors, the acidic microenvironment that is generated as a by-product of metabolism, to develop a novel approach of using pH (Low) Insertion Peptides (pHLIPs) for imaging of PDAC. We show that fluorescently labeled pHLIPs can localize and specifically detect PDAC in human xenografts as well as PDAC and PanIN lesions in genetically engineered mouse models. This novel approach may improve detection, differential diagnosis and staging of PDAC.

Dhat syndrome: Evolution of concept, current understanding, and need of an integrated approach

Directory of Open Access Journals (Sweden)

Sujita Kumar Kar

2015-01-01

Full Text Available Dhat syndrome has often been construed as a culture-bound sexual neurosis of the Indian subcontinent. Symptoms similar to that of Dhat syndrome has been described in other cultures across different time periods. The present paper looks at the evolution of the concept of Dhat syndrome in India. The review also takes an overview of the current understanding of this syndrome in terms of nosological status as a distinct entity and its "culture-bound" status. The narrative finally attempts to discuss the integrated approach for the treatment of this disorder.

Current trends in dextranomer hyaluronic acid copolymer (Deflux) injection technique for endoscopic treatment of vesicoureteral reflux.

Science.gov (United States)

Kirsch, Andrew J; Arlen, Angela M; Lackgren, Goran

2014-08-01

To determine the current preferred injection technique(s) for endoscopic management of pediatric vesicoureteral reflux (VUR). Since the approval of dextranomer hyaluronic acid copolymer (Dx/HA) in 2001, injection methods have evolved and now include the hydrodistention implantation technique (HIT) and double HIT as well as subureteral transurethral injection (STING) method. In July 2012, 278 pediatric urologists in the United States were contacted to complete a 15-question survey regarding Dx/HA injection technique(s) currently used in their practice. Fifty board-certified pediatric urologists completed the survey for a response rate of 18%. Most respondents (60%) were in a single-specialty group practice, and 12% were affiliated with an academic- or university-based practice. Respondents reported seeing a mean of 159 pediatric patients (range, 40-400 patients) with VUR annually, and 94% used Dx/HA ≥4 times in the past year. Forty-seven respondents (94%) reported using double HIT over the course of their career compared with 36 (72%) for STING and 30 (60%) for HIT (P injection techniques. A significantly higher percentage currently perform double HIT (92%) compared with either STING (24%) or HIT (34%; P <.001). Respondents reported the use of double HIT 15 times more often than STING technique and 5 times more often than HIT during the past 12 months (P <.001). The double HIT method is currently the most commonly performed technique for endoscopic correction of VUR by pediatric urologists in the United States. Copyright © 2014 Elsevier Inc. All rights reserved.

Pubertal induction in hypogonadism: Current approaches including use of gonadotrophins.

Science.gov (United States)

Zacharin, Margaret

2015-06-01

Primary disorders of the gonad or those secondary to abnormalities of the hypothalamic pituitary axis result in hypogonadism. The range of health problems of childhood and adolescence that affect this axis has increased, as most children now survive chronic illness, but many have persisting deficits in gonadal function as a result of their underlying condition or its treatment. An integrated approach to hormone replacement is needed to optimize adult hormonal and bone health, and to offer opportunities for fertility induction and preservation that were not considered possible in the past. Timing of presentation ranges from birth, with disorders of sexual development, through adolescent pubertal failure, to adult fertility problems. This review addresses diagnosis and management of hypogonadism and focuses on new management strategies to address current concerns with fertility preservation. These include Turner syndrome, and fertility presevation prior to childhood cancer treatment. New strategies for male hormone replacement therapy that may impinge upon future fertility are emphasized. Copyright © 2015 Elsevier Ltd. All rights reserved.

A novel approach for acid mine drainage pollution biomonitoring using rare earth elements bioaccumulated in the freshwater clam Corbicula fluminea.

Science.gov (United States)

Bonnail, Estefanía; Pérez-López, Rafael; Sarmiento, Aguasanta M; Nieto, José Miguel; DelValls, T Ángel

2017-09-15

Lanthanide series have been used as a record of the water-rock interaction and work as a tool for identifying impacts of acid mine drainage (lixiviate residue derived from sulphide oxidation). The application of North-American Shale Composite-normalized rare earth elements patterns to these minority elements allows determining the origin of the contamination. In the current study, geochemical patterns were applied to rare earth elements bioaccumulated in the soft tissue of the freshwater clam Corbicula fluminea after exposure to different acid mine drainage contaminated environments. Results show significant bioaccumulation of rare earth elements in soft tissue of the clam after 14 days of exposure to acid mine drainage contaminated sediment (ΣREE=1.3-8μg/gdw). Furthermore, it was possible to biomonitor different degrees of contamination based on rare earth elements in tissue. The pattern of this type of contamination describes a particular curve characterized by an enrichment in the middle rare earth elements; a homologous pattern (E MREE =0.90) has also been observed when applied NASC normalization in clam tissues. Results of lanthanides found in clams were contrasted with the paucity of toxicity studies, determining risk caused by light rare earth elements in the Odiel River close to the Estuary. The current study purposes the use of clam as an innovative "bio-tool" for the biogeochemical monitoring of pollution inputs that determines the acid mine drainage networks affection. Copyright © 2017 Elsevier B.V. All rights reserved.

Eddy current crack detection capability assessment approach using crack specimens with differing electrical conductivity

Science.gov (United States)

Koshti, Ajay M.

2018-03-01

Like other NDE methods, eddy current surface crack detectability is determined using probability of detection (POD) demonstration. The POD demonstration involves eddy current testing of surface crack specimens with known crack sizes. Reliably detectable flaw size, denoted by, a90/95 is determined by statistical analysis of POD test data. The surface crack specimens shall be made from a similar material with electrical conductivity close to the part conductivity. A calibration standard with electro-discharged machined (EDM) notches is typically used in eddy current testing for surface crack detection. The calibration standard conductivity shall be within +/- 15% of the part conductivity. This condition is also applicable to the POD demonstration crack set. Here, a case is considered, where conductivity of the crack specimens available for POD testing differs by more than 15% from that of the part to be inspected. Therefore, a direct POD demonstration of reliably detectable flaw size is not applicable. Additional testing is necessary to use the demonstrated POD test data. An approach to estimate the reliably detectable flaw size in eddy current testing for part made from material A using POD crack specimens made from material B with different conductivity is provided. The approach uses additional test data obtained on EDM notch specimens made from materials A and B. EDM notch test data from the two materials is used to create a transfer function between the demonstrated a90/95 size on crack specimens made of material B and the estimated a90/95 size for part made of material A. Two methods are given. For method A, a90/95 crack size for material B is given and POD data is available. Objective of method A is to determine a90/95 crack size for material A using the same relative decision threshold that was used for material B. For method B, target crack size a90/95 for material A is known. Objective is to determine decision threshold for inspecting material A.

Acidic pit lakes. The legacy of coal and metal surface mines

Energy Technology Data Exchange (ETDEWEB)

Geller, Walter; Schultze, Martin [Helmholtz Centre for Environmental Research - UFZ, Magdeburg (Germany); Wolkersdorfer, Christian (eds.) [Cape Breton Univ., Sydney, NS (Canada). Industrial Research Chair in Mine Water Remediation and Management; International Mine Water Association, Wendelstein (Germany). General Secretary; Kleinmann, Robert

2013-07-01

This monograph provides an international perspective on pit lakes in post-mining landscapes, including the problem of geogenic acidification. Much has been learned during the last decade through research and practical experience on how to mitigate or remediate the environmental problems of acidic pit lakes. In the first part of the book, general scientific issues are presented in 21 contributions from the fields of geo-environmental science, water chemistry, lake physics, lake modeling, and on the peculiar biological features that occur in the extreme habitats of acidic pit lakes. Another chapter provides an overview of methods currently used to remediate acidic pit lakes and treat outflowing acidic water. The second part of the book is a collection of regional surveys of pit lake problems from three European countries and Australia, and case studies of various individual representative lakes. A final case study provides an innovative approach to assessing the economic value of new pit lakes and balancing the costs and benefits, a valuable tool for decision makers.

Reconciling current approaches to blindsight

DEFF Research Database (Denmark)

Overgaard, Morten; Mogensen, Jesper

2015-01-01

After decades of research, blindsight is still a mysterious and controversial topic in consciousness research. Currently, many researchers tend to think of it as an ideal phenomenon to investigate neural correlates of consciousness, whereas others believe that blindsight is in fact a kind...... of degraded vision rather than "truly blind". This article considers both perspectives and finds that both have difficulties understanding all existing evidence about blindsight. In order to reconcile the perspectives, we suggest two specific criteria for a good model of blindsight, able to encompass all...

The territorial approach to EU cohesion policy: Current issues and evidence from Greece

Directory of Open Access Journals (Sweden)

Thoidou Elisavet

2011-01-01

Full Text Available The importance attributed to the territorial dimension of the European Union cohesion policy steadily influences its successive reforms and adaptations, while in recent years there has been an evolution in the way this particular dimension of cohesion policy is perceived. Important evidence for this is the way in which the Community Strategic Guidelines on cohesion 2007-13 take account of the territorial dimension of cohesion policy. This paper discusses the territorial approach to cohesion policy in relation to both policy and practice. Specifically, it examines the territorial dimension of regional development planning in Greece as it has emerged in the relevant official documents, namely the successive three Community Support Frameworks since 1989 and the National Strategic Reference Framework for the current 2007-13 period. The territorial dimension of the organization of the planning system is also considered in an effort to understand limitations and prospects, in light of the importance of the territorial approach to cohesion policy post-2013.

Real-time electrochemical monitoring of isothermal helicase-dependent amplification of nucleic acids.

Science.gov (United States)

Kivlehan, Francine; Mavré, François; Talini, Luc; Limoges, Benoît; Marchal, Damien

2011-09-21

We described an electrochemical method to monitor in real-time the isothermal helicase-dependent amplification of nucleic acids. The principle of detection is simple and well-adapted to the development of portable, easy-to-use and inexpensive nucleic acids detection technologies. It consists of monitoring a decrease in the electrochemical current response of a reporter DNA intercalating redox probe during the isothermal DNA amplification. The method offers the possibility to quantitatively analyze target nucleic acids in less than one hour at a single constant temperature, and to perform at the end of the isothermal amplification a DNA melt curve analysis for differentiating between specific and non-specific amplifications. To illustrate the potentialities of this approach for the development of a simple, robust and low-cost instrument with high throughput capability, the method was validated with an electrochemical system capable of monitoring up to 48 real-time isothermal HDA reactions simultaneously in a disposable microplate consisting of 48-electrochemical microwells. Results obtained with this approach are comparable to that obtained with a well-established but more sophisticated and expensive fluorescence-based method. This makes for a promising alternative detection method not only for real-time isothermal helicase-dependent amplification of nucleic acid, but also for other isothermal DNA amplification strategies.

Formation of nitric acid hydrates - A chemical equilibrium approach

Science.gov (United States)

Smith, Roland H.

1990-01-01

Published data are used to calculate equilibrium constants for reactions of the formation of nitric acid hydrates over the temperature range 190 to 205 K. Standard enthalpies of formation and standard entropies are calculated for the tri- and mono-hydrates. These are shown to be in reasonable agreement with earlier calorimetric measurements. The formation of nitric acid trihydrate in the polar stratosphere is discussed in terms of these equilibrium constants.

CodonTest: modeling amino acid substitution preferences in coding sequences.

Directory of Open Access Journals (Sweden)

Wayne Delport

2010-08-01

Full Text Available Codon models of evolution have facilitated the interpretation of selective forces operating on genomes. These models, however, assume a single rate of non-synonymous substitution irrespective of the nature of amino acids being exchanged. Recent developments have shown that models which allow for amino acid pairs to have independent rates of substitution offer improved fit over single rate models. However, these approaches have been limited by the necessity for large alignments in their estimation. An alternative approach is to assume that substitution rates between amino acid pairs can be subdivided into rate classes, dependent on the information content of the alignment. However, given the combinatorially large number of such models, an efficient model search strategy is needed. Here we develop a Genetic Algorithm (GA method for the estimation of such models. A GA is used to assign amino acid substitution pairs to a series of rate classes, where is estimated from the alignment. Other parameters of the phylogenetic Markov model, including substitution rates, character frequencies and branch lengths are estimated using standard maximum likelihood optimization procedures. We apply the GA to empirical alignments and show improved model fit over existing models of codon evolution. Our results suggest that current models are poor approximations of protein evolution and thus gene and organism specific multi-rate models that incorporate amino acid substitution biases are preferred. We further anticipate that the clustering of amino acid substitution rates into classes will be biologically informative, such that genes with similar functions exhibit similar clustering, and hence this clustering will be useful for the evolutionary fingerprinting of genes.

The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

Directory of Open Access Journals (Sweden)

S. A. Watmough

2002-01-01

Full Text Available The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not change over time (i.e. a best case scenario. In addition, because soils in the region are shallow, base cation weathering rates for the representative sub-catchments were calculated for the entire soil profile and these estimates were also used to calculate critical loads for the lakes. These results were compared with critical loads obtained by the Steady State Water Chemistry (SSWC model. Using the SSWC model, critical loads for lakes were between 7 and 19 meq m-2yr-1 higher than those obtained from soil measurements. Lakes and forests are much more sensitive to acid deposition if forests are harvested, but two acid-sensitive lakes had much lower critical loads than their respective forested sub-catchments implying that acceptable acid deposition levels should be dictated by the most acid-sensitive lakes in the region. Under conditions that assume harvesting, the CL (A is exceeded at two of the three lakes and five of the six sub-catchments assessed in this study. However, sulphate export from catchments greatly exceeds input in bulk deposition and, to prevent lakes from falling below the critical chemical limit, sulphate inputs to lakes must be reduced by between 37% and 92% if forests are harvested. Similarly, sulphate leaching from forested catchments that are harvested must be reduced by between 16 and 79% to prevent the ANC of water draining the rooting zone from falling below 0 μeq l-1. These calculations assume that extremely low calcium leaching losses (9–27 μeq l-1 from

Land administration in Ecuador; Current situation and opportunities with adoption of fit-for-purpose land administration approach

NARCIS (Netherlands)

Todorovski, D.; Salazar, Rodolfo; Jacome, Ginella; Bermeo, Antonio; Orellana, Esteban; Zambrano, Fatima; Teran, Andrea; Mejia, Raul

2018-01-01

The aim of this paper is to explore current land administration situation in Ecuador and identify opportunities for fit-for-purpose (FFP) land administration approach that could improve the land administration functions for the country and its citizens. In this paper, initially literature about land

A frequency domain approach to analyzing passive battery-ultracapacitor hybrids supplying periodic pulsed current loads

International Nuclear Information System (INIS)

Kuperman, Alon; Aharon, Ilan; Kara, Avi; Malki, Shalev

2011-01-01

Highlights: → Passive battery-ultracapacitor hybrids are examined. → Frequency domain analysis is employed. → The ultracapacitor branch operates as a low-pass filter for the battery. → The battery supplies the average load demand. → Design requirements are discussed. - Abstract: A Fourier-based analysis of passive battery-ultracapacitor hybrid sources is introduced in the manuscript. The approach is first introduced for a general load, and then is followed by a study for a case of periodic pulsed current load. It is shown that the ultracapacitor branch is perceived by the battery as a low-pass filter, which absorbs the majority of the high frequency harmonic current and letting the battery to supply the average load demand in addition to the small part of dynamic current. Design requirements influence on the ultracapacitor capacitance and internal resistance choice are quantitatively discussed. The theory is enforced by simulation and experimental results, showing an excellent agreement.

A cost-effective approach to produce 15N-labelled amino acids employing Chlamydomonas reinhardtii CC503.

Science.gov (United States)

Nicolás Carcelén, Jesús; Marchante-Gayón, Juan Manuel; González, Pablo Rodríguez; Valledor, Luis; Cañal, María Jesús; Alonso, José Ignacio García

2017-08-18

The use of enriched stable isotopes is of outstanding importance in chemical metrology as it allows the application of isotope dilution mass spectrometry (IDMS). Primary methods based on IDMS ensure the quality of the analytical measurements and traceability of the results to the international system of units. However, the synthesis of isotopically labelled molecules from enriched stable isotopes is an expensive and a difficult task. Either chemical and biochemical methods to produce labelled molecules have been proposed, but so far, few cost-effective methods have been described. The aim of this study was to use the microalgae Chlamydomonas reinhardtii to produce, at laboratory scale, 15 N-labelled amino acids with a high isotopic enrichment. To do that, a culture media containing 15 NH 4 Cl was used. No kinetic isotope effect (KIE) was observed. The labelled proteins biosynthesized by the microorganism were extracted from the biomass and the 15 N-labelled amino acids were obtained after a protein hydrolysis with HCl. The use of the wall deficient strain CC503 cw92 mt+ is fit for purpose, as it only assimilates ammonia as nitrogen source, avoiding isotope contamination with nitrogen from the atmosphere or the reagents used in the culture medium, and enhancing the protein extraction efficiency compared to cell-walled wild type Chlamydomonas. The isotopic enrichment of the labelled amino acids was calculated from their isotopic composition measured by gas chromatography mass spectrometry (GC-MS). The average isotopic enrichment for the 16 amino acids characterized was 99.56 ± 0.05% and the concentration of the amino acids in the hydrolysate ranged from 18 to 90 µg/mL. Previously reported biochemical methods to produce isotopically labelled proteins have been applied in the fields of proteomics and fluxomics. For these approaches, low amounts of products are required and the isotopic enrichment of the molecules has never been properly determined. So far, only 13

Cancer-related anorexia/cachexia syndrome and oxidative stress: an innovative approach beyond current treatment.

Science.gov (United States)

Mantovani, Giovanni; Madeddu, Clelia; Macciò, Antonio; Gramignano, Giulia; Lusso, Maria Rita; Massa, Elena; Astara, Giorgio; Serpe, Roberto

2004-10-01

Cancer-related anorexia/cachexia syndrome and oxidative stress play a key role in the progression and outcome of neoplastic disease. On the basis of our previously published studies and clinical experience, we have developed an innovative approach consisting of diet with high polyphenol content (400 mg), p.o. pharmaconutritional support enriched with n - 3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) 2 cans (237 mL each) per day, medroxiprogesterone acetate 500 mg/d, antioxidant treatment with alpha-lipoic acid 300 mg/d plus carbocysteine lysine salt 2.7 g/d plus vitamin E 400 mg/d plus vitamin A 30,000 IU/d plus vitamin C 500 mg/d, and selective cyclooxygenase-2 inhibitor Celecoxib 200 mg/d. The treatment is administered for 16 weeks. The following variables are evaluated: (a) clinical variables (stage and Eastern Cooperative Oncology Group performance status); (b) nutritional variables (lean body mass, appetite, and resting energy expenditure); (c) laboratory variables (serum levels of proinflammatory cytokines, C-reactive protein, and leptin and blood levels of reactive oxygen species and antioxidant enzymes); and (d) quality of life variables (European Organization for Research and Treatment of Cancer QLQ-C30, EQ-5Dindex, and EQ-5DVAS). A phase II nonrandomized study has been designed to enroll 40 patients with advanced cancer at different sites with symptoms of cancer-related anorexia/cachexia syndrome and oxidative stress. As of January 2004, 28 patients have been enrolled: 25 patients were evaluable and 14 of them have completed the treatment (20 patients have completed 2 months of treatment). As for clinical response, five patients improved, three patients remained unchanged, and six patients worsened. The Eastern Cooperative Oncology Group performance status (grade) 1 remained unchanged. As for nutritional/functional variables, the lean body mass increased significantly at 2 and 4 months. As for laboratory variables, reactive oxygen species

An enantioselective approach toward 3,4-dihydroisocoumarin through the bromocyclization of styrene-type carboxylic acids.

Science.gov (United States)

Chen, Jie; Zhou, Ling; Tan, Chong Kiat; Yeung, Ying-Yeung

2012-01-20

A facile and enantioselective approach toward 3,4-dihydroisocoumarin was developed. The method involved an amino-thiocarbamate catalyzed enantioselective bromocyclization of styrene-type carboxylic acids, yielding 3-bromo-3,4-dihydroisocoumarins with good yields and ee's. 3-Bromo-3,4-dihydroisocoumarins are versatile building blocks for various dihydroisocoumarin derivatives in which the Br group can readily be modified to achieve biologically important 4-O-type and 4-N-type 3,4-dihydroisocoumarin systems. In addition, studies indicated that, by refining some parameters, the synthetically useful 5-exo phthalide products could be achieved with good yields and ee's.

A Study of Frequency Mixing Approaches for Eddy Current Testing of Steam Generator Tubes

International Nuclear Information System (INIS)

Jung, Hee Jun; Song, Sung Jin; Kim, Chang Hwan; Kim, Dae Kwang

2009-01-01

The multifrequency eddy current testing(ECT) have been proposed various frequency mixing algorithms. In this study, we compare these approaches to frequency mixing of ECT signals from steam generator tubes; time-domain optimization, discrete cosine transform-domain optimization. Specifically, in this study, two different frequency mixing algorithms, a time-domain optimization method and a discrete cosine transform(DCT) optimization method, are investigated using the experimental signals captured from the ASME standard tube. The DCT domain optimization method is computationally fast but produces larger amount of residue.

Flow Regime Identification of Co-Current Downward Two-Phase Flow With Neural Network Approach

International Nuclear Information System (INIS)

Hiroshi Goda; Seungjin Kim; Ye Mi; Finch, Joshua P.; Mamoru Ishii; Jennifer Uhle

2002-01-01

Flow regime identification for an adiabatic vertical co-current downward air-water two-phase flow in the 25.4 mm ID and the 50.8 mm ID round tubes was performed by employing an impedance void meter coupled with the neural network classification approach. This approach minimizes the subjective judgment in determining the flow regimes. The signals obtained by an impedance void meter were applied to train the self-organizing neural network to categorize these impedance signals into a certain number of groups. The characteristic parameters set into the neural network classification included the mean, standard deviation and skewness of impedance signals in the present experiment. The classification categories adopted in the present investigation were four widely accepted flow regimes, viz. bubbly, slug, churn-turbulent, and annular flows. These four flow regimes were recognized based upon the conventional flow visualization approach by a high-speed motion analyzer. The resulting flow regime maps classified by the neural network were compared with the results obtained through the flow visualization method, and consequently the efficiency of the neural network classification for flow regime identification was demonstrated. (authors)

Effect of acute acid loading on acid-base and calcium metabolism

DEFF Research Database (Denmark)

Osther, Palle J

2006-01-01

OBJECTIVE: To investigate the acid-base and calcium metabolic responses to acute non-carbonic acid loading in idiopathic calcium stone-formers and healthy males using a quantitative organ physiological approach. MATERIAL AND METHODS: Five-h ammonium chloride loading studies were performed in 12...... male recurrent idiopathic calcium stone-formers and 12 matched healthy men using a randomized, placebo-controlled, cross-over design. Arterialized capillary blood, serum and urine were collected hourly for measurement of electrolytes, ionized calcium, magnesium, phosphate, parathyroid hormone and acid-base...... status. Concentrations of non-metabolizable base (NB) and acid (NA) were calculated from measured concentrations of non-metabolizable ions. RESULTS: The extracellular acid-base status in the stone-formers during basal conditions and acid loading was comparable to the levels in the healthy controls...

The development of an approach to assess critical loads of acidity for woodland habitats in Great Britain

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S. J. Langan

2004-01-01

Full Text Available Alongside other countries that are signatories to the UNECE Convention Long Range Transboundary on Air Pollution, the UK is committed to reducing the impact of air pollution on the environment. To advise and guide this policy in relation to atmospheric emissions of sulphur and nitrogen, a critical load approach has been developed. To assess the potential impact of these pollutants on woodland habitats a steady state, simple mass balance model has been parameterised. For mineral soils, a Ca:Al ratio in soil solution has been used as the critical load indicator for potential damage. For peat and organic soils critical loads have been set according to a pH criterion. Together these approaches have been used with national datasets to examine the potential scale of acidification in woodland habitats across the UK. The results can be mapped to show the spatial variability in critical loads of the three principal woodland habitat types (managed coniferous, managed broadleaved/ mixed woodland and unmanaged woodland. The results suggest that there is a wide range of critical loads. The most sensitive (lowest critical loads are associated with managed coniferous followed by unmanaged woodland on peat soils. Calculations indicate that at steady state, acid deposition inputs reported for 1995–1997 result in a large proportion of all the woodland habitats identified receiving deposition loads in excess of their critical load; i.e. critical loads are exceeded. These are discussed in relation to future modelled depositions for 2010. Whilst significant widespread negative impacts of such deposition on UK woodland habitats have not been reported, the work serves to illustrate that if acid deposition inputs were maintained and projected emissions reductions not achieved, the long-term sustainability of large areas of woodland in the UK could be compromised. Keywords: critical loads, acid deposition, acidification, woodland, simple mass balance model

Developing nucleic acid-based electrical detection systems

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Gabig-Ciminska Magdalena

2006-03-01

Full Text Available Abstract Development of nucleic acid-based detection systems is the main focus of many research groups and high technology companies. The enormous work done in this field is particularly due to the broad versatility and variety of these sensing devices. From optical to electrical systems, from label-dependent to label-free approaches, from single to multi-analyte and array formats, this wide range of possibilities makes the research field very diversified and competitive. New challenges and requirements for an ideal detector suitable for nucleic acid analysis include high sensitivity and high specificity protocol that can be completed in a relatively short time offering at the same time low detection limit. Moreover, systems that can be miniaturized and automated present a significant advantage over conventional technology, especially if detection is needed in the field. Electrical system technology for nucleic acid-based detection is an enabling mode for making miniaturized to micro- and nanometer scale bio-monitoring devices via the fusion of modern micro- and nanofabrication technology and molecular biotechnology. The electrical biosensors that rely on the conversion of the Watson-Crick base-pair recognition event into a useful electrical signal are advancing rapidly, and recently are receiving much attention as a valuable tool for microbial pathogen detection. Pathogens may pose a serious threat to humans, animal and plants, thus their detection and analysis is a significant element of public health. Although different conventional methods for detection of pathogenic microorganisms and their toxins exist and are currently being applied, improvements of molecular-based detection methodologies have changed these traditional detection techniques and introduced a new era of rapid, miniaturized and automated electrical chip detection technologies into pathogen identification sector. In this review some developments and current directions in

Drugs acting on amino acid neurotransmitters.

Science.gov (United States)

Meldrum, B S

1986-01-01

The most potent agents currently available for suppressing myoclonic activity in animals and humans act to enhance GABA-mediated inhibition and/or to diminish amino acid-induced excitation. Postsynaptic GABA-mediated inhibition plays an important role at the cortical level, diminishing the effect of augmented afferent activity and preventing pathologically enhanced output. Enhancement of GABAergic inhibition, principally at the cortical level but also at lower levels, by clonazepam and by valproate appears to be a predominant element in their antimyoclonic action. Studies in various animal models, including photically induced myoclonus in the baboon, P papio, indicate the value of other approaches to enhancing GABA-mediated inhibition. Among such approaches meriting evaluation in humans are inhibition of GABA-transaminase activity by gamma-vinyl GABA and action at some of the benzodiazepine receptors to enhance the action of GABA, as by the novel anticonvulsant beta-carbolines. Excitatory transmission mediated by dicarboxylic amino acids appears to play a role in myoclonus, especially at the spinal level, but also in the brainstem, cerebellum, basal ganglia, and cortex. Among various novel agents that act at the postsynaptic receptor site to antagonize such excitation, those specifically blocking excitation induced by aspartate and/or NMDA prevent myoclonic activity in a wide range of animal models. Further research is required before such agents can be evaluated in humans.

Efficacy of Lactic Acid, Lactic Acid-Acetic Acid Blends, and Peracetic Acid To Reduce Salmonella on Chicken Parts under Simulated Commercial Processing Conditions.

Science.gov (United States)

Ramirex-Hernandez, Alejandra; Brashears, Mindy M; Sanchez-Plata, Marcos X

2018-01-01

The poultry processing industry has been undergoing a series of changes as it modifies processing practices to comply with new performance standards for chicken parts and comminuted poultry products. The regulatory approach encourages the use of intervention strategies to prevent and control foodborne pathogens in poultry products and thus improve food safety and protect human health. The present studies were conducted to evaluate the efficacy of antimicrobial interventions for reducing Salmonella on inoculated chicken parts under simulated commercial processing conditions. Chicken pieces were inoculated by immersion in a five-strain Salmonella cocktail at 6 log CFU/mL and then treated with organic acids and oxidizing agents on a commercial rinsing conveyor belt. The efficacy of spraying with six different treatments (sterile water, lactic acid, acetic acid, buffered lactic acid, acetic acid in combination with lactic acid, and peracetic acid) at two concentrations was evaluated on skin-on and skin-off chicken thighs at three application temperatures. Skinless chicken breasts were used to evaluate the antimicrobial efficacy of lactic acid and peracetic acid. The color stability of treated and untreated chicken parts was assessed after the acid interventions. The lactic acid and buffered lactic acid treatments produced the greatest reductions in Salmonella counts. Significant differences between the control and water treatments were identified for 5.11% lactic acid and 5.85% buffered lactic acid in both skin-on and skin-off chicken thighs. No significant effect of treatment temperature for skin-on chicken thighs was found. Lactic acid and peracetic acid were effective agents for eluting Salmonella cells attached to chicken breasts.

Electrophysiological and Behavioral Effects of Combined Transcranial Direct Current Stimulation and Alcohol Approach Bias Retraining in Hazardous Drinkers

NARCIS (Netherlands)

den Uyl, T.E.; Gladwin, T.E.; Wiers, R.W.

2016-01-01

BACKGROUND: Cognitive bias modification (CBM) can be used to retrain automatic approach tendencies for alcohol. We investigated whether changing cortical excitability with transcranial direct current stimulation (tDCS) could enhance CBM effects in hazardous drinkers. We also studied the underlying

Acid rain information book. Final report

International Nuclear Information System (INIS)

1983-05-01

Acid rain is one of the most widely publicized environmental issues of the day. The potential consequences of widespread acid rain demand that the phenomenon be carefully evaluated. Review of the literature shows a rapidly growing body of knowledge, but also reveals major gaps in understanding that need to be narrowed. This document discusses aspects of the acid rain phenomenon, points out areas of uncertainty and summarizes current and projected research. The report is organized by a logical progression from sources of pollutants affecting acid rain formation to the atmospheric transport and transformation of those pollutants and finally to the deposition of acid rain, the effects of that deposition, and possible mitigative measures and regulatory options. This information is followed by a discussion of uncertainties in the understanding of the acid rain phenomenon and a description of current and proposed research by responsible government agencies and other concerned organizations

Implementation of systematic training approach in Kozloduy Training Centre - Current situation. Presentation of Bulgaria

International Nuclear Information System (INIS)

Kosturkov, L.

1993-01-01

To identify the needs in implementation of the systematic training approach, a relation between the number of trainees, duration of the training and the type of training should be made. In other hand, as it was stated in the TWG-T(93) Status Report, in order to be better identified outstanding training needs, the existing capabilities and other related projects should be taken into account. This report is pointed to give more details for the current situation in Bulgaria and to clarify the needs of international assistance. 3 refs, 3 tabs

Formic acid oxidation at platinum-bismuth catalysts

Directory of Open Access Journals (Sweden)

Popović Ksenija Đ.

2015-01-01

Full Text Available The field of heterogeneous catalysis, specifically catalysis on bimetallic surfaces, has seen many advances over the past few decades. Bimetallic catalysts, which often show electronic and chemical properties that are distinct from those of their parent metals, offer the opportunity to obtain new catalysts with enhanced selectivity, activity, and stability. The oxidation of formic acid is of permanent interest as a model reaction for the mechanistic understanding of the electrooxidation of small organic molecules and because of its technical relevance for fuel cell applications. Platinum is one of the most commonly used catalysts for this reaction, despite the fact that it shows a few significant disadvantages: high cost and extreme susceptibility to poisoning by CO. To solve this problem, several approaches have been used, but generally, they all consist in the modification of platinum with a second element. Especially, bismuth has received significant attention as Pt modifier. According to the results presented in this survey dealing with the effects influencing the formic acid oxidation it was found that two types of Pt-Bi bimetallic catalysts (bulk and low loading deposits on GC showed superior catalytic activity in terms of the lower onset potential and oxidation current density, as well as exceptional stability compared to Pt. The findings in this report are important for the understanding of mechanism of formic acid electrooxidation on a bulk alloy and decorated surface, for the development of advanced anode catalysts for direct formic acid fuel cells, as well as for the synthesis of novel low-loading bimetallic catalysts. The use of bimetallic compounds as the anode catalysts is an effective solution to overcoming the problems of the formic acid oxidation current stability for long term applications. In the future, the tolerance of both CO poisoning and electrochemical leaching should be considered as the key factors in the development

Evaluation of Current Approaches to Stream Classification and a Heuristic Guide to Developing Classifications of Integrated Aquatic Networks

Science.gov (United States)

Melles, S. J.; Jones, N. E.; Schmidt, B. J.

2014-03-01

Conservation and management of fresh flowing waters involves evaluating and managing effects of cumulative impacts on the aquatic environment from disturbances such as: land use change, point and nonpoint source pollution, the creation of dams and reservoirs, mining, and fishing. To assess effects of these changes on associated biotic communities it is necessary to monitor and report on the status of lotic ecosystems. A variety of stream classification methods are available to assist with these tasks, and such methods attempt to provide a systematic approach to modeling and understanding complex aquatic systems at various spatial and temporal scales. Of the vast number of approaches that exist, it is useful to group them into three main types. The first involves modeling longitudinal species turnover patterns within large drainage basins and relating these patterns to environmental predictors collected at reach and upstream catchment scales; the second uses regionalized hierarchical classification to create multi-scale, spatially homogenous aquatic ecoregions by grouping adjacent catchments together based on environmental similarities; and the third approach groups sites together on the basis of similarities in their environmental conditions both within and between catchments, independent of their geographic location. We review the literature with a focus on more recent classifications to examine the strengths and weaknesses of the different approaches. We identify gaps or problems with the current approaches, and we propose an eight-step heuristic process that may assist with development of more flexible and integrated aquatic classifications based on the current understanding, network thinking, and theoretical underpinnings.

Current approaches to gene regulatory network modelling

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Brazma Alvis

2007-09-01

Full Text Available Abstract Many different approaches have been developed to model and simulate gene regulatory networks. We proposed the following categories for gene regulatory network models: network parts lists, network topology models, network control logic models, and dynamic models. Here we will describe some examples for each of these categories. We will study the topology of gene regulatory networks in yeast in more detail, comparing a direct network derived from transcription factor binding data and an indirect network derived from genome-wide expression data in mutants. Regarding the network dynamics we briefly describe discrete and continuous approaches to network modelling, then describe a hybrid model called Finite State Linear Model and demonstrate that some simple network dynamics can be simulated in this model.

Nucleic acid-functionalized transition metal nanosheets for biosensing applications.

Science.gov (United States)

Mo, Liuting; Li, Juan; Liu, Qiaoling; Qiu, Liping; Tan, Weihong

2017-03-15

In clinical diagnostics, as well as food and environmental safety practices, biosensors are powerful tools for monitoring biological or biochemical processes. Two-dimensional (2D) transition metal nanomaterials, including transition metal chalcogenides (TMCs) and transition metal oxides (TMOs), are receiving growing interest for their use in biosensing applications based on such unique properties as high surface area and fluorescence quenching abilities. Meanwhile, nucleic acid probes based on Watson-Crick base-pairing rules are also being widely applied in biosensing based on their excellent recognition capability. In particular, the emergence of functional nucleic acids in the 1980s, especially aptamers, has substantially extended the recognition capability of nucleic acids to various targets, ranging from small organic molecules and metal ions to proteins and cells. Based on π-π stacking interaction between transition metal nanosheets and nucleic acids, biosensing systems can be easily assembled. Therefore, the combination of 2D transition metal nanomaterials and nucleic acids brings intriguing opportunities in bioanalysis and biomedicine. In this review, we summarize recent advances of nucleic acid-functionalized transition metal nanosheets in biosensing applications. The structure and properties of 2D transition metal nanomaterials are first discussed, emphasizing the interaction between transition metal nanosheets and nucleic acids. Then, the applications of nucleic acid-functionalized transition metal nanosheet-based biosensors are discussed in the context of different signal transducing mechanisms, including optical and electrochemical approaches. Finally, we provide our perspectives on the current challenges and opportunities in this promising field. Copyright © 2016 Elsevier B.V. All rights reserved.

CURRENT APPROACHES FOR RESEARCH OF MULTIPLE SCLEROSIS BIOMARKERS

Directory of Open Access Journals (Sweden)

Kolyada T.I

2016-12-01

Full Text Available Current data concerning features of multiple sclerosis (MS etiology, pathogenesis, clinical course and treatment of disease indicate the necessity of personalized approach to the management of MS patients. These features are the variety of possible etiological factors and mechanisms that trigger the development of MS, different courses of disease, and significant differences in treatment efficiency. Phenotypic and pathogenetic heterogeneity of MS requires, on the one hand, the stratification of patients into groups with different treatment depending on a number of criteria including genetic characteristics, disease course, stage of the pathological process, and forms of the disease. On the other hand, it requires the use of modern methods for assessment of individual risk of developing MS, its early diagnosis, evaluation and prognosis of the disease course and the treatment efficiency. This approach is based on the identification and determination of biomarkers of MS including the use of systems biology technology platforms such as genomics, proteomics, metabolomics and bioinformatics. Research and practical use of biomarkers of MS in clinical and laboratory practice requires the use of a wide range of modern medical and biological, mathematical and physicochemical methods. The group of "classical" methods used to study MS biomarkers includes physicochemical and immunological methods aimed at the selection and identification of single molecular biomarkers, as well as methods of molecular genetic analysis. This group of methods includes ELISA, western blotting, isoelectric focusing, immunohistochemical methods, flow cytometry, spectrophotometric and nephelometric methods. These techniques make it possible to carry out both qualitative and quantitative assay of molecular biomarkers. The group of "classical methods" can also include methods based on polymerase chain reaction (including multiplex and allele-specific PCR and genome sequencing

Multilevel Molecular Modeling Approach for a Rational Design of Ionic Current Sensors for Nanofluidics.

Science.gov (United States)

Kirch, Alexsandro; de Almeida, James M; Miranda, Caetano R

2018-05-10

The complexity displayed by nanofluidic-based systems involves electronic and dynamic aspects occurring across different size and time scales. To properly model such kind of system, we introduced a top-down multilevel approach, combining molecular dynamics simulations (MD) with first-principles electronic transport calculations. The potential of this technique was demonstrated by investigating how the water and ionic flow through a (6,6) carbon nanotube (CNT) influences its electronic transport properties. We showed that the confinement on the CNT favors the partially hydrated Na, Cl, and Li ions to exchange charge with the nanotube. This leads to a change in the electronic transmittance, allowing for the distinguishing of cations from anions. Such an ionic trace may handle an indirect measurement of the ionic current that is recorded as a sensing output. With this case study, we are able to show the potential of this top-down multilevel approach, to be applied on the design of novel nanofluidic devices.

Current Approaches to Tactical Performance Analyses in Soccer Using Position Data.

Science.gov (United States)

Memmert, Daniel; Lemmink, Koen A P M; Sampaio, Jaime

2017-01-01

Tactical match performance depends on the quality of actions of individual players or teams in space and time during match-play in order to be successful. Technological innovations have led to new possibilities to capture accurate spatio-temporal information of all players and unravel the dynamics and complexity of soccer matches. The main aim of this article is to give an overview of the current state of development of the analysis of position data in soccer. Based on the same single set of position data of a high-level 11 versus 11 match (Bayern Munich against FC Barcelona) three different promising approaches from the perspective of dynamic systems and neural networks will be presented: Tactical performance analysis revealed inter-player coordination, inter-team and inter-line coordination before critical events, as well as team-team interaction and compactness coefficients. This could lead to a multi-disciplinary discussion on match analyses in sport science and new avenues for theoretical and practical implications in soccer.

Current Perspectives on Desmoid Tumors: The Mayo Clinic Approach

International Nuclear Information System (INIS)

Joglekar, Siddharth B.; Rose, Peter S.; Sim, Franklin; Okuno, Scott; Petersen, Ivy

2011-01-01

Desmoid tumors are a rare group of locally aggressive, non malignant tumors of fibroblastic origin that can lead to significant morbidity due to local invasion. Despite advances in the understanding of these tumors, their natural history is incompletely understood and the optimal treatment is still a matter of debate. Local control is the main goal of treatment and there has been a change in philosophy regarding the management of these tumors from aggressive surgical resection to function preservation. A multidisciplinary approach is essential to plan local control with acceptable morbidity. The current Mayo Clinic algorithm for the treatment of these tumors is based on institutional experience and the available evidence in the literature: asymptomatic/non progressive lesions away from vital structures are managed with observation and regular imaging; primary or recurrent desmoid tumors which are symptomatic or progressive or near vital structures are managed with wide surgical resection when wide surgical margins are possible with minimal functional and cosmetic loss. When positive or close surgical margins are likely, surgical resection with adjuvant radiotherapy or definitive radiotherapy is preferred. If likely functional or cosmetic deficit is unacceptable, radiotherapy is the treatment of choice. Unresectable lesions are considered for radiotherapy, chemotherapy or newer modalities however an unresectable lesion associated with a painful, functionless, infected extremity is managed with an amputation

Current Perspectives on Desmoid Tumors: The Mayo Clinic Approach

Directory of Open Access Journals (Sweden)

Scott Okuno

2011-08-01

Full Text Available Desmoid tumors are a rare group of locally aggressive, non malignant tumors of fibroblastic origin that can lead to significant morbidity due to local invasion. Despite advances in the understanding of these tumors, their natural history is incompletely understood and the optimal treatment is still a matter of debate. Local control is the main goal of treatment and there has been a change in philosophy regarding the management of these tumors from aggressive surgical resection to function preservation. A multidisciplinary approach is essential to plan local control with acceptable morbidity. The current Mayo Clinic algorithm for the treatment of these tumors is based on institutional experience and the available evidence in the literature: asymptomatic/non progressive lesions away from vital structures are managed with observation and regular imaging; primary or recurrent desmoid tumors which are symptomatic or progressive or near vital structures are managed with wide surgical resection when wide surgical margins are possible with minimal functional and cosmetic loss. When positive or close surgical margins are likely, surgical resection with adjuvant radiotherapy or definitive radiotherapy is preferred. If likely functional or cosmetic deficit is unacceptable, radiotherapy is the treatment of choice. Unresectable lesions are considered for radiotherapy, chemotherapy or newer modalities however an unresectable lesion associated with a painful, functionless, infected extremity is managed with an amputation.

A MapReduce approach to diminish imbalance parameters for big deoxyribonucleic acid dataset.

Science.gov (United States)

Kamal, Sarwar; Ripon, Shamim Hasnat; Dey, Nilanjan; Ashour, Amira S; Santhi, V

2016-07-01

In the age of information superhighway, big data play a significant role in information processing, extractions, retrieving and management. In computational biology, the continuous challenge is to manage the biological data. Data mining techniques are sometimes imperfect for new space and time requirements. Thus, it is critical to process massive amounts of data to retrieve knowledge. The existing software and automated tools to handle big data sets are not sufficient. As a result, an expandable mining technique that enfolds the large storage and processing capability of distributed or parallel processing platforms is essential. In this analysis, a contemporary distributed clustering methodology for imbalance data reduction using k-nearest neighbor (K-NN) classification approach has been introduced. The pivotal objective of this work is to illustrate real training data sets with reduced amount of elements or instances. These reduced amounts of data sets will ensure faster data classification and standard storage management with less sensitivity. However, general data reduction methods cannot manage very big data sets. To minimize these difficulties, a MapReduce-oriented framework is designed using various clusters of automated contents, comprising multiple algorithmic approaches. To test the proposed approach, a real DNA (deoxyribonucleic acid) dataset that consists of 90 million pairs has been used. The proposed model reduces the imbalance data sets from large-scale data sets without loss of its accuracy. The obtained results depict that MapReduce based K-NN classifier provided accurate results for big data of DNA. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Investigation of eddy currents in the components of the dynamic ergodic divertor of TEXTOR using analytical and numerical approaches

International Nuclear Information System (INIS)

Giesen, B.; Neubauer, O.; Bondarchuk, E.; Doinikov, N.; Kitaev, B.; Obidenko, T.; Panin, A.

2003-01-01

Analytical and numerical approaches for the calculation of eddy currents in mechanical structures of the TEXTOR tokamak in view of operating the dynamic ergodic divertor (DED) coil system fed with the alternating current up to 15 kA at frequencies up to 10 kHz are described. The design of the in-vessel components located close to the DED coils requires detailed investigation of eddy current effects to avoid unacceptable heating and forces. Different approaches depending on skin-layer depths compared with the body dimensions are analyzed. The applied algorithms are based on analytical and simplified numerical methods. Precision and application range of these algorithms have been checked by a numerical code. The simplified technique is rather effective for first step engineering estimation and gives a good understanding for the problem. In a certain parameter range, it results in even precise values and can be used for design optimization of the structures without huge efforts in numerical modeling. After modification of the component's shape prototypes have been manufactured and successfully tested in a full-scale model under the real DED field. The design recommendations resulting from the eddy current studies contributed significantly to the optimized lay out of the DED in-vessel components

Biowaiver Monographs for Immediate-Release Solid Oral Dosage Forms: Folic Acid.

Science.gov (United States)

Hofsäss, Martin A; Souza, Jacqueline de; Silva-Barcellos, Neila M; Bellavinha, Karime R; Abrahamsson, Bertil; Cristofoletti, Rodrigo; Groot, D W; Parr, Alan; Langguth, Peter; Polli, James E; Shah, Vinod P; Tajiri, Tomokazu; Mehta, Mehul U; Dressman, Jennifer B

2017-12-01

This work presents a review of literature and experimental data relevant to the possibility of waiving pharmacokinetic bioequivalence studies in human volunteers for approval of immediate-release solid oral pharmaceutical forms containing folic acid as the single active pharmaceutical ingredient. For dosage forms containing 5 mg folic acid, the highest dose strength on the World Health Organization Essential Medicines List, the dose/solubility ratio calculated from solubility studies was higher than 250 mL, corresponding to a classification as "not highly soluble." Small, physiological doses of folic acid (≤320 μg) seem to be absorbed completely via active transport, but permeability data for higher doses of 1-5 mg are inconclusive. Following a conservative approach, folic acid is classified as a Biopharmaceutics Classification System class IV compound until more reliable data become available. Commensurate with its solubility characteristics, the results of dissolution studies indicated that none of the folic acid products evaluated showed rapid dissolution in media at pH 1.2 or 4.5. Therefore, according to the current criteria of the Biopharmaceutics Classification System, the biowaiver approval procedure cannot be recommended for immediate-release solid oral dosage forms containing folic acid. Copyright © 2017 American Pharmacists Association®. All rights reserved.

Acid production potentials of massive sulfide minerals and lead-zinc mine tailings: a medium-term study.

Science.gov (United States)

Çelebi, Emin Ender; Öncel, Mehmet Salim; Kobya, Mehmet

2018-01-01

Weathering of sulfide minerals is a principal source of acid generation. To determine acid-forming potentials of sulfide-bearing materials, two basic approaches named static and kinetic tests are available. Static tests are short-term, and easily undertaken within a few days and in a laboratory. In contrast, kinetic tests are long-term procedures and mostly carried out on site. In this study, experiments were conducted over a medium-term period of 2 months, not as short as static tests and also not as long as kinetic tests. As a result, pH and electrical conductivity oscillations as a function of time, acid-forming potentials and elemental contents of synthetically prepared rainwater leachates of massive sulfides and sulfide-bearing lead-zinc tailings from abandoned and currently used deposition areas have been determined. Although the lowest final pH of 2.70 was obtained in massive pyrite leachate, massive chalcopyrite leachate showed the highest titrable acidity of 1.764 g H 2 SO 4 /L. On the other hand, a composite of currently deposited mine tailings showed no acidic characteristic with a final pH of 7.77. The composite abandoned mine tailing leachate had a final pH of 6.70, close to the final pH of massive galena and sphalerite leachates, and produced a slight titrable acidity of 0.130 g H 2 SO 4 /L.

Excitatory amino acid transmitters in epilepsy.

Science.gov (United States)

Meldrum, B S

1991-01-01

For the majority of human epilepsy syndromes, the molecular and cellular basis for the epileptic activity remains largely conjectural. The principal hypotheses currently concern: defects in membrane ionic conductances or transport mechanisms; defects in gamma-aminobutyric acid (GABA)-mediated inhibitory processes; and enhanced or abnormal excitatory synaptic action. Substantial evidence exists in humans and animals for acquired abnormalities in excitatory amino acid neurotransmission that may participate in the abnormal patterns of neuronal discharge, and this could provide the morphological basis for a recurrent excitatory pathway sustaining seizure discharges in temporal lobe epilepsy. In practice, two approaches appear significant in the suppression of seizures. One is to act postsynaptically on receptors to decrease the excitation induced by glutamate, and the other is to decrease synaptic release of glutamate and aspartate. Agents acting upon adenosine or GABAB receptors decrease glutamate release in vitro but do not have significant anticonvulsant activity, probably because of their predominant actions at other sites. Lamotrigine blocks stimulated release of glutamate and shows anticonvulsant activity in a wide range of animal models.

Distributions of 12 elements on 64 absorbers from simulated Hanford Neutralized Current Acid Waste (NCAW)

International Nuclear Information System (INIS)

Svitra, Z.V.; Bowen, S.M.; Marsh, S.F.

1994-12-01

As part of the Hanford Tank Waste Remediation System program at Los Alamos, we evaluated 64 commercially available or experimental absorber materials for their ability to remove hazardous components from high-level waste. These absorbers included cation and anion exchange resins, inorganic exchangers, composite absorbers, and a series of liquid extractants sorbed on porous support-beads. We tested these absorbers with a solution that simulates Hanford neutralized current acid waste (NCAW) (pH 14.2). To this simulant solution we added the appropriate radionuclides and used gamma spectrometry to measure fission products (Cs, Sr, Tc, and Y) and matrix elements (Cr, Co, Fe, Mn, Ni, V, Zn, and Zr). For each of 768 element/absorber combinations, we measured distribution coefficients for dynamic contact periods of 30 min, 2 h, and 6 h to obtain information about sorption kinetics. On the basis of these 2304 measured distribution coefficients, we determined that many of the tested absorbers may be suitable for processing NCAW solutions

Underlying role of mitochondrial mutagenesis in the pathogenesis of a disease and current approaches for translational research.

Science.gov (United States)

Paraskevaidi, Maria; Martin-Hirsch, Pierre L; Kyrgiou, Maria; Martin, Francis L

2017-05-01

Mitochondrial diseases have been extensively investigated over the last three decades, but many questions regarding their underlying aetiologies remain unanswered. Mitochondrial dysfunction is not only responsible for a range of neurological and myopathy diseases but also considered pivotal in a broader spectrum of common diseases such as epilepsy, autism and bipolar disorder. These disorders are a challenge to diagnose and treat, as their aetiology might be multifactorial. In this review, the focus is placed on potential mechanisms capable of introducing defects in mitochondria resulting in disease. Special attention is given to the influence of xenobiotics on mitochondria; environmental factors inducing mutations or epigenetic changes in the mitochondrial genome can alter its expression and impair the whole cell's functionality. Specifically, we suggest that environmental agents can cause damage in mitochondrial DNA and consequently lead to mutagenesis. Moreover, we describe current approaches for handling mitochondrial diseases, as well as available prenatal diagnostic tests, towards eliminating these maternally inherited diseases. Undoubtedly, more research is required, as current therapeutic approaches mostly employ palliative therapies rather than targeting primary mechanisms or prophylactic approaches. Much effort is needed into further unravelling the relationship between xenobiotics and mitochondria, as the extent of influence in mitochondrial pathogenesis is increasingly recognised. © The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

ECAPS - Eddy Current Approach and Proximity Satellites

Data.gov (United States)

National Aeronautics and Space Administration — Multiple, energized coils in a small satellite will generate eddy currents in the skin of the International Space Station (ISS). This will create repulsive forces...

Approaches to chronic disease management evaluation in use in Europe : A review of current methods and performance measures

NARCIS (Netherlands)

Conklin, A.; Nolte, E.; Vrijhoef, H.J.M.

2013-01-01

Objectives: An overview was produced of approaches currently used to evaluate chronic disease management in selected European countries. The study aims to describe the methods and metrics used in Europe as a first to help advance the methodological basis for their assessment. Methods: A common

Exploring Education Culture by Employing Hofstede?s Cultural Dimensions to Evaluate the Effectiveness of the Current ERP Training Approach in Thailand

Science.gov (United States)

Chayakonvikom, Monta; Fuangvut, Parin; Cannell, Stephen

2016-01-01

ERP training is a critical success factor in ERP implementation. The current ERP training was largely ineffective and caused user resistance and ERP implementation failure. The objective of this paper is to investigate whether the current ERP training approach can accommodate the cultural learning behaviors of end-users. Hofstede's cultural…

A Review of Player Monitoring Approaches in Basketball: Current Trends and Future Directions.

Science.gov (United States)

Fox, Jordan L; Scanlan, Aaron T; Stanton, Robert

2017-07-01

Fox, JL, Scanlan, AT, and Stanton, R. A review of player monitoring approaches in basketball: current trends and future directions. J Strength Cond Res 31(7): 2021-2029, 2017-Effective monitoring of players in team sports such as basketball requires an understanding of the external demands and internal responses, as they relate to training phases and competition. Monitoring of external demands and internal responses allows coaching staff to determine the dose-response associated with the imposed training load (TL), and subsequently, if players are adequately prepared for competition. This review discusses measures reported in the literature for monitoring the external demands and internal responses of basketball players during training and competition. The external demands of training and competition were primarily monitored using time-motion analysis, with limited use of microtechnology being reported. Internal responses during training were typically measured using hematological markers, heart rate, various TL models, and perceptual responses such as rating of perceived exertion (RPE). Heart rate was the most commonly reported indicator of internal responses during competition with limited reporting of hematological markers or RPE. These findings show a large discrepancy between the reporting of external and internal measures and training and competition demands. Microsensors, however, may be a practical and convenient method of player monitoring in basketball to overcome the limitations associated with current approaches while allowing for external demands and internal responses to be recorded simultaneously. The triaxial accelerometers of microsensors seem well suited for basketball and warrant validation to definitively determine their place in the monitoring of basketball players. Coaching staff should make use of this technology by tracking individual player responses across the annual plan and using real-time monitoring to minimize factors such as fatigue

Formic Acid Electrooxidation by a Platinum Nanotubule Array Electrode

Directory of Open Access Journals (Sweden)

Eric Broaddus

2013-01-01

Full Text Available One-dimensional metallic nanostructures such as nanowires, rods, and tubes have drawn much attention for electrocatalytic applications due to potential advantages that include fewer diffusion impeding interfaces with polymeric binders, more facile pathways for electron transfer, and more effective exposure of active surface sites. 1D nanostructured electrodes have been fabricated using a variety of methods, typically showing improved current response which has been attributed to improved CO tolerance, enhanced surface activity, and/or improved transport characteristics. A template wetting approach was used to fabricate an array of platinum nanotubules which were examined electrochemically with regard to the electrooxidation of formic acid. Arrays of 100 and 200 nm nanotubules were compared to a traditional platinum black catalyst, all of which were found to have similar surface areas. Peak formic acid oxidation current was observed to be highest for the 100 nm nanotubule array, followed by the 200 nm array and the Pt black; however, CO tolerance of all electrodes was similar, as were the onset potentials of the oxidation and reduction peaks. The higher current response was attributed to enhanced mass transfer in the nanotubule electrodes, likely due to a combination of both the more open nanostructure as well as the lack of a polymeric binder in the catalyst layer.

Acid rain information book. Second edition

International Nuclear Information System (INIS)

1983-05-01

Potential consequences of widespread acid precipitation are reviewed through an extensive literature search. Major aspects of the acid rain phenomena are discussed, areas of uncertainty identified, and current research summarized

Model prediction for ranking lead-acid batteries according to expected lifetime in renewable energy systems and autonomous power-supply systems

DEFF Research Database (Denmark)

Schiffer, J.; Sauer, D.U.; Bindner, Henrik W.

2007-01-01

-of-discharge, the current rate, the existing acid stratification, and the time since the last full charging. The actual Ah throughput is continuously multiplied by a weight factor that represents the actual operating conditions. Even though the modelling approach is mainly heuristic, all of the effects that are taken...

A combinatorial approach to detect coevolved amino acid networks in protein families of variable divergence.

Directory of Open Access Journals (Sweden)

Julie Baussand

2009-09-01

Full Text Available Communication between distant sites often defines the biological role of a protein: amino acid long-range interactions are as important in binding specificity, allosteric regulation and conformational change as residues directly contacting the substrate. The maintaining of functional and structural coupling of long-range interacting residues requires coevolution of these residues. Networks of interaction between coevolved residues can be reconstructed, and from the networks, one can possibly derive insights into functional mechanisms for the protein family. We propose a combinatorial method for mapping conserved networks of amino acid interactions in a protein which is based on the analysis of a set of aligned sequences, the associated distance tree and the combinatorics of its subtrees. The degree of coevolution of all pairs of coevolved residues is identified numerically, and networks are reconstructed with a dedicated clustering algorithm. The method drops the constraints on high sequence divergence limiting the range of applicability of the statistical approaches previously proposed. We apply the method to four protein families where we show an accurate detection of functional networks and the possibility to treat sets of protein sequences of variable divergence.

Omics approaches on fresh-cut lettuce reveal global molecular responses to sodium hypochlorite and peracetic acid treatment.

Science.gov (United States)

Daddiego, Loretta; Bianco, Linda; Capodicasa, Cristina; Carbone, Fabrizio; Dalmastri, Claudia; Daroda, Lorenza; Del Fiore, Antonella; De Rossi, Patrizia; Di Carli, Mariasole; Donini, Marcello; Lopez, Loredana; Mengoni, Alessio; Paganin, Patrizia; Perrotta, Gaetano; Bevivino, Annamaria

2018-01-01

Lettuce is a leafy vegetable that is extensively commercialized as a ready-to-eat product because of its widespread use in human nutrition as salad. It is well known that washing treatments can severely affect the quality and shelf-life of ready-to-eat vegetables. The study presented here evaluated the effect of two washing procedures on fresh-cut lettuce during storage. An omics approach was applied to reveal global changes at molecular level induced by peracetic acid washing in comparison with sodium hypochlorite treatment. Microbiological analyses were also performed to quantify total bacterial abundance and composition. The study revealed wide metabolic alterations induced by the two sanitizers. In particular, transcriptomic and proteomic analyses pointed out a number of transcripts and proteins differentially accumulated in response to peracetic acid washing, mainly occurring on the first day of storage. In parallel, different microbiota composition and significant reduction in total bacterial load following washing were also observed. The results provide useful information for the fresh-cut industry to select an appropriate washing procedure preserving fresh-like attributes as much as possible during storage of the end product. Molecular evidence indicated peracetic acid to be a valid alternative to sodium hypochlorite as sanitizer solution. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Far-red fluorescent probes for canonical and non-canonical nucleic acid structures: current progress and future implications.

Science.gov (United States)

Suseela, Y V; Narayanaswamy, Nagarjun; Pratihar, Sumon; Govindaraju, Thimmaiah

2018-02-05

The structural diversity and functional relevance of nucleic acids (NAs), mainly deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), are indispensable for almost all living organisms, with minute aberrations in their structure and function becoming causative factors in numerous human diseases. The standard structures of NAs, termed canonical structures, are supported by Watson-Crick hydrogen bonding. Under special physiological conditions, NAs adopt distinct spatial organisations, giving rise to non-canonical conformations supported by hydrogen bonding other than the Watson-Crick type; such non-canonical structures have a definite function in controlling gene expression and are considered as novel diagnostic and therapeutic targets. Development of molecular probes for these canonical and non-canonical DNA/RNA structures has been an active field of research. Among the numerous probes studied, probes with turn-on fluorescence in the far-red (600-750 nm) region are highly sought-after due to minimal autofluorescence and cellular damage. Far-red fluorescent probes are vital for real-time imaging of NAs in live cells as they provide good resolution and minimal perturbation of the cell under investigation. In this review, we present recent advances in the area of far-red fluorescent probes of DNA/RNA and non-canonical G-quadruplex structures. For the sake of continuity and completeness, we provide a brief overview of visible fluorescent probes. Utmost importance is given to design criteria, characteristic properties and biological applications, including in cellulo imaging, apart from critical discussion on limitations of the far-red fluorescent probes. Finally, we offer current and future prospects in targeting canonical and non-canonical NAs specific to cellular organelles, through sequence- and conformation-specific far-red fluorescent probes. We also cover their implications in chemical and molecular biology, with particular focus on decoding various disease

Succinic Acid: Technology Development and Commercialization

Directory of Open Access Journals (Sweden)

Nhuan P. Nghiem

2017-06-01

Full Text Available Succinic acid is a precursor of many important, large-volume industrial chemicals and consumer products. It was once common knowledge that many ruminant microorganisms accumulated succinic acid under anaerobic conditions. However, it was not until the discovery of Anaerobiospirillum succiniciproducens at the Michigan Biotechnology Institute (MBI, which was capable of producing succinic acid up to about 50 g/L under optimum conditions, that the commercial feasibility of producing the compound by biological processes was realized. Other microbial strains capable of producing succinic acid to high final concentrations subsequently were isolated and engineered, followed by development of fermentation processes for their uses. Processes for recovery and purification of succinic acid from fermentation broths were simultaneously established along with new applications of succinic acid, e.g., production of biodegradable deicing compounds and solvents. Several technologies for the fermentation-based production of succinic acid and the subsequent conversion to useful products are currently commercialized. This review gives a summary of the development of microbial strains, their fermentation, and the importance of the down-stream recovery and purification efforts to suit various applications in the context of their current commercialization status for biologically derived succinic acid.

THE INFLUENCE OF THIOSEMICARBAZONE 2,3-DIHYDROXYBENZALDEHYDE ON CATALYTIC CURRENTS IN THE SYSTEM MOLYBDENUM (VI – POTASSIUM CHLORATE IN ACID SULFATE SOLUTIONS

Directory of Open Access Journals (Sweden)

Ludmila Chiriac

2011-06-01

Full Text Available The polarographic catalytic current in acid solutions of Mo(VI, thiosemicarbazone 2,3-dihydroxybenzaldehyde (TSC 2,3-DHBA and chlorate ions has been investigated. The scheme of reactions, taking place in the solutions and on the electrode, has been proposed. The increase of the catalytic current is explained by the formation of an active intermediate complex [Mo(V×TSC 2,3-DHBA (ClO-3]. The rate constant of this complex formation K = 2.56 × 106 mol-1×dm3×s-1, the activation energy Ea = 15.9 kcal×mol-1 and the reaction activation entropy ∆Sa¹ = -23.5 e.u. have been calculated.

Current status and emerging role of glutathione in food grade lactic acid bacteria

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Pophaly Sarang

2012-08-01

Full Text Available Abstract Lactic acid bacteria (LAB have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms.

A diagrammatic description of the equations of motion, current and noise within the second-order von Neumann approach

International Nuclear Information System (INIS)

Karlström, O; Pedersen, J N; Bergenfeldt, C; Samuelsson, P; Wacker, A; Emary, C; Zedler, P; Brandes, T

2013-01-01

We investigate the second-order von Neumann approach from a diagrammatic point of view and demonstrate its equivalence with the resonant tunneling approximation. The investigation of higher order diagrams shows that the method correctly reproduces the equation of motion for the single-particle reduced density matrix of an arbitrary non-interacting many-body system. This explains why the method reproduces the current exactly for such systems. We go on to show, however, that diagrams not included in the method are needed to calculate exactly higher cumulants of the charge transport. This thorough comparison sheds light on the validity of all these self-consistent second-order approaches. We analyze the discrepancy between the noise calculated by our method and the exact Levitov formula for a simple non-interacting quantum dot model. Furthermore, we study the noise of the canyon of current suppression in a two-level dot, a phenomenon that requires the inclusion of electron–electron interaction as well as higher order tunneling processes. (paper)

New Acid Combination for a Successful Sandstone Acidizing

Science.gov (United States)

Shafiq, M. U.; Mahmud, H. K. B.; Rezaee, R.

2017-05-01

With the development of new enhanced oil recovery techniques, sandstone acidizing has been introduced and played a pivotal role in the petroleum industry. Different acid combinations have been applied, which react with the formation, dissolve the soluble particles; thus increase the production of hydrocarbons. To solve the problems which occurred using current preflush sandstone acidizing technology (hydrochloric acid); a new acid combination has been developed. Core flooding experiments on sandstone core samples with dimensions 1.5 in. × 3 in. were conducted at a flow rate of 2 cm3/min. A series of hydrochloric-acetic acid mixtures with different ratios were tested under 150°F temperature. The core flooding experiments performed are aimed to dissolve carbonate, sodium, potassium and calcium particles from the core samples. These experiments are followed by few important tests which include, porosity-permeability, pH value, Inductively Coupled Plasma (ICP) analysis and Nuclear Magnetic Resonance (NMR measurements). All the results are compared with the results of conventional hydrochloric acid technology. NMR and porosity analysis concluded that the new acid combination is more effective in creating fresh pore spaces and thus increasing the reservoir permeability. It can be seen from the pore distribution before and after the acidizing. Prior applying acid; the large size of pores appears most frequently in the pore distribution while with the applied acid, it was found that the small pore size is most the predominant of the pore distribution. These results are validated using ICP analysis which shows the effective removal of calcium and other positive ions from the core sample. This study concludes that the combination of acetic-hydrochloric acid can be a potential candidate for the preflush stage of sandstone acidizing at high temperature reservoirs.

Discovery of a novel amino acid racemase through exploration of natural variation in Arabidopsis thaliana

Science.gov (United States)

Strauch, Renee C.; Svedin, Elisabeth; Dilkes, Brian; Chapple, Clint; Li, Xu

2015-01-01

Plants produce diverse low-molecular-weight compounds via specialized metabolism. Discovery of the pathways underlying production of these metabolites is an important challenge for harnessing the huge chemical diversity and catalytic potential in the plant kingdom for human uses, but this effort is often encumbered by the necessity to initially identify compounds of interest or purify a catalyst involved in their synthesis. As an alternative approach, we have performed untargeted metabolite profiling and genome-wide association analysis on 440 natural accessions of Arabidopsis thaliana. This approach allowed us to establish genetic linkages between metabolites and genes. Investigation of one of the metabolite–gene associations led to the identification of N-malonyl-d-allo-isoleucine, and the discovery of a novel amino acid racemase involved in its biosynthesis. This finding provides, to our knowledge, the first functional characterization of a eukaryotic member of a large and widely conserved phenazine biosynthesis protein PhzF-like protein family. Unlike most of known eukaryotic amino acid racemases, the newly discovered enzyme does not require pyridoxal 5′-phosphate for its activity. This study thus identifies a new d-amino acid racemase gene family and advances our knowledge of plant d-amino acid metabolism that is currently largely unexplored. It also demonstrates that exploitation of natural metabolic variation by integrating metabolomics with genome-wide association is a powerful approach for functional genomics study of specialized metabolism. PMID:26324904

Current issues in determining dietary protein and amino-acid requirements

DEFF Research Database (Denmark)

Pencharz, P; Jahoor, F; Kurpad, A

2014-01-01

Pregnancy and the first two years of life are periods of rapid growth and yet the knowledge of requirements for protein and dietary indispensable amino acids is very limited. The development of carbon oxidation methods opens the way to studies that should fill these important gaps in knowledge.Eu.......European Journal of Clinical Nutrition advance online publication, 15 January 2014; doi:10.1038/ejcn.2013.297....

Catalyzed oxidation reactions. IV. Picolinic acid catalysis of chromic acid oxidations

International Nuclear Information System (INIS)

Rocek, J.; Peng, T.Y.

1977-01-01

Picolinic acid and several closely related acids are effective catalysts in the chromic acid oxidation of primary and secondary alcohols; the oxidation of other substrates is accelerated only moderately. The reaction is first order in chromium-(VI), alcohol, and picolinic acid; it is second order in hydrogen ions at low acidity and approaches acidity independence at high perchloric acid concentrations. A primary deuterium kinetic isotope effect is observed at high but not at low acidities. At low acidity the reaction has a considerably lower activation energy and more negative activation entropy than at higher acidities. The reactive intermediate in the proposed mechanism is a negatively charged termolecular complex formed from chromic acid, picolinic acid, and alcohol. The rate-limiting step of the reaction changes with the acidity of the solution. At higher acidities the intermediate termolecular complex is formed reversibly and the overall reaction rate is determined by the rate of its decomposition into reaction products; at low acidities the formation of the complex is irreversible and hence rate limiting. Picolinic acids with a substituent in the 6 position show a greatly reduced catalytic activity. This observation is interpreted as suggesting a square pyramidal or octahedral structure for the reactive chromium (VI) intermediate. The temperature dependence of the deuterium isotope effect has been determined and the significance of the observed large values for E/sub a//sup D/ - E/sub a//sup H/ and A/sup D//A/sup H/ is discussed

Bioequivalence evaluation of two brands of amoxicillin/clavulanic acid 250/125 mg combination tablets in healthy human volunteers: use of replicate design approach.

Science.gov (United States)

Idkaidek, Nasir M; Al-Ghazawi, Ahmad; Najib, Naji M

2004-12-01

The purpose of this study was to apply a replicate design approach to a bioequivalence study of amoxicillin/clavulanic acid combination following a 250/125 mg oral dose to 23 subjects, and to compare the analysis of individual bioequivalence with average bioequivalence. This was conducted as a 2-treatment 2-sequence 4-period crossover study. Average bioequivalence was shown, while the results from the individual bioequivalence approach had no success in showing bioequivalence. In conclusion, the individual bioequivalence approach is a strong statistical tool to test for intra-subject variances and also subject-by-formulation interaction variance compared with the average bioequivalence approach. copyright (c) 2004 John Wiley & Sons, Ltd.

Gas Antisolvent Approach for the Precipitation of α -Methoxyphenylacetic Acid – ( R -1-Cyclohexylethylamine Diateromeric Salt

Directory of Open Access Journals (Sweden)

A. Zodge

2017-10-01

Full Text Available One of the major drawbacks of diastereomeric salt precipitation based enantioseparation is the time and solvent requirement of crystallization. In the gas antisolvent (GAS approach, supercritical carbon dioxide is applied as an antisolvent, and the precipitation takes place in a couple of minutes. By setting the process parameters diastereomeric excess, yields, and selectivity can be controlled. Applicability of the process is demonstrated on the resolution of racemic 2-methoxyphenylacetic acid with enantiopure (R-(−-1-cyclohexylethylamine. Diastereomeric excess values over 55 % along with 80 % yields were achieved at optimal conditions in a single step.

Post-operative complications after removal of sporadic vestibular schwannoma via retrosigmoid-suboccipital approach: current diagnosis and management.

Science.gov (United States)

Charalampakis, Stylianos; Koutsimpelas, Dimitrios; Gouveris, Haralampos; Mann, Wolf

2011-05-01

The retrosigmoid (suboccipital) approach is one of four surgical approaches for the treatment of vestibular schwannomas (acoustic neuromas). It is increasingly used by otologic surgeons, and in experienced hands is associated with improved results and more limited complications. Mortality rates are minimal and often zero, while postoperative sequelae, on the other hand, are not rare. In order to not only save the patient's life, but also to assure good quality of life after the surgery, one must consider many different aspects of management of the respective complications. In this review the issues of current management of CSF leak and meningitis, facial paresis, headache, hearing loss, unsteadiness, disequilibrium, vertigo, tinnitus, cerebellar and brain stem injuries or abscess, vascular complications and venous air embolism after retrosigmoid approach for removal of vestibular schwannomas are presented. © Springer-Verlag 2011

Yeast and bacterial diversity along a transect in an acidic, As-Fe rich environment revealed by cultural approaches.

Science.gov (United States)

Delavat, François; Lett, Marie-Claire; Lièvremont, Didier

2013-10-01

Acid mine drainages (AMDs) are often thought to harbour low biodiversity, yet little is known about the diversity distribution along the drainages. Using culture-dependent approaches, the microbial diversity from the Carnoulès AMD sediment was investigated for the first time along a transect showing progressive environmental stringency decrease. In total, 20 bacterial genera were detected, highlighting a higher bacterial diversity than previously thought. Moreover, this approach led to the discovery of 16 yeast species, demonstrating for the first time the presence of this important phylogenetic group in this AMD. All in all, the location of the microbes along the transect helps to better understand their distribution in a pollution gradient. Copyright © 2013 Elsevier B.V. All rights reserved.

The potential for military diets to reduce depression, suicide, and impulsive aggression: a review of current evidence for omega-3 and omega-6 fatty acids.

Science.gov (United States)

Hibbeln, Joseph R; Gow, Rachel V

2014-11-01

The current burden of psychological distress and illness poses as a significant barrier to optimal force efficacy. Here we assess nutrients in military diets, specifically highly unsaturated essential fatty acids, in the reduction of risk or treatment of psychiatric distress. Moderate to strong evidence from several meta-analyses of prospective cohort trials indicate that Mediterranean diet patterns reduce risk of clinical depressions. Specific nutrients and foods of biological interest in relation to mental health outcomes are then discussed and evaluated. Moderate evidence indicates that when fish consumption decreases and simultaneously omega-6 increases, the risk of clinical depressive symptoms are elevated. One meta-analysis examining tissue compositions provides moderate to strong evidence that higher levels of omega-3 highly unsaturated fatty acids (HUFAs) (eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) are associated with decreased risk of clinical depressions. Other meta-analytic reviews of randomized placebo-controlled trials provide moderate to strong evidence of significantly improving clinically depressive symptoms when the formulation given was >50% in eicosapentaenoic acid. Finally, a meta-analysis of omega-3 HUFAs provides modest evidence of clinical efficacy for attention-deficit hyperactivity disorder. This article recommends that a rebalancing of the essential fatty acid composition of U.S. military diets, achieve tissue compositions of HUFAs consistent with traditional Mediterranean diets, may help reduce military psychiatric distress and simultaneously increase force efficacy substantially. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

Light-cone AdS/CFT-adapted approach to AdS fields/currents, shadows, and conformal fields

Energy Technology Data Exchange (ETDEWEB)

Metsaev, R.R. [Department of Theoretical Physics, P.N. Lebedev Physical Institute, Leninsky prospect 53, Moscow 119991 (Russian Federation)

2015-10-16

Light-cone gauge formulation of fields in AdS space and conformal field theory in flat space adapted for the study of AdS/CFT correspondence is developed. Arbitrary spin mixed-symmetry fields in AdS space and arbitrary spin mixed-symmetry currents, shadows, and conformal fields in flat space are considered on an equal footing. For the massless and massive fields in AdS and the conformal fields in flat space, simple light-cone gauge actions leading to decoupled equations of motion are found. For the currents and shadows, simple expressions for all 2-point functions are also found. We demonstrate that representation of conformal algebra generators on space of currents, shadows, and conformal fields can be built in terms of spin operators entering the light-cone gauge formulation of AdS fields. This considerably simplifies the study of AdS/CFT correspondence. Light-cone gauge actions for totally symmetric arbitrary spin long conformal fields in flat space are presented. We apply our approach to the study of totally antisymmetric (one-column) and mixed-symmetry (two-column) fields in AdS space and currents, shadows, and conformal fields in flat space.

A systems approach for discovering linoleic acid derivatives that potentially mediate pain and itch

Science.gov (United States)

Ramsden, Christopher E.; Domenichiello, Anthony F.; Yuan, Zhi-Xin; Sapio, Matthew R.; Keyes, Gregory S.; Mishra, Santosh K.; Gross, Jacklyn R.; Majchrzak-Hong, Sharon; Zamora, Daisy; Horowitz, Mark S.; Davis, John M.; Sorokin, Alexander V.; Dey, Amit; LaPaglia, Danielle M.; Wheeler, Joshua J.; Vasko, Michael R.; Mehta, Nehal N.; Mannes, Andrew J.; Iadarola, Michael J.

2018-01-01

Chronic pain and itch are common hypersensitivity syndromes that are affected by endogenous mediators. We applied a systems-based, translational approach to predict, discover, and characterize mediators of pain and itch that are regulated by diet and inflammation. Profiling of tissue-specific precursor abundance and biosynthetic gene expression predicted that inflamed skin would be abundant in four previously unknown 11-hydroxy-epoxy-or 11-keto-epoxy-octadecenoate linoleic acid derivatives and four previously identified 9- or 13-hydroxy-epoxy- or 9- or 13-keto-epoxy-octadecenoate linoleic acid derivatives. All of these mediators were confirmed to be abundant in rat and human skin by mass spectrometry. However, only the two 11-hydroxy-epoxy-octadecenoates sensitized rat dorsal root ganglion neurons to release more calcitonin gene–related peptide (CGRP), which is involved in pain transmission, in response to low pH (which mimics an inflammatory state) or capsaicin (which activates ion channels involved in nociception). The two 11-hydroxy-epoxy-octadecenoates share a 3-hydroxy-Z-pentenyl-E-epoxide moiety, thus suggesting that this substructure could mediate nociceptor sensitization. In rats, intradermal hind paw injection of 11-hydroxy-12,13-trans-epoxy-(9Z)-octadecenoate elicited C-fiber–mediated sensitivity to thermal pain. In a randomized trial testing adjunctive strategies to manage refractory chronic headaches, reducing the dietary intake of linoleic acid was associated with decreases in plasma 11-hydroxy-12,13-trans-epoxy-(9Z)-octadecenoate, which correlated with clinical pain reduction. Human psoriatic skin had 30-fold higher 9-keto-12,13-trans-epoxy-(10E)-octadecenoate compared to control skin, and intradermal injection of this compound induced itch-related scratching behavior in mice. Collectively, these findings define a family of endogenous mediators with potential roles in pain and itch. PMID:28831021

Use of Biosensors as Alternatives to Current Regulatory Methods for Marine Biotoxins

Directory of Open Access Journals (Sweden)

Luis M. Botana

2009-11-01

Full Text Available Marine toxins are currently monitored by means of a bioassay that requires the use of many mice, which poses a technical and ethical problem in many countries. With the exception of domoic acid, there is a legal requirement for the presence of other toxins (yessotoxin, saxitoxin and analogs, okadaic acid and analogs, pectenotoxins and azaspiracids in seafood to be controlled by bioassay, but other toxins, such as palytoxin, cyclic imines, ciguatera and tetrodotoxin are potentially present in European food and there are no legal requirements or technical approaches available to identify their presence. The need for alternative methods to the bioassay is clearly important, and biosensors have become in recent years a feasible alternative to animal sacrifice. This review will discuss the advantages and disadvantages of using biosensors as alternatives to animal assays for marine toxins, with particular focus on surface plasmon resonance (SPR technology.

Treatment for spasmodic dysphonia: limitations of current approaches

Science.gov (United States)

Ludlow, Christy L.

2009-01-01

Purpose of review Although botulinum toxin injection is the gold standard for treatment of spasmodic dysphonia, surgical approaches aimed at providing long-term symptom control have been advancing over recent years. Recent findings When surgical approaches provide greater long-term benefits to symptom control, they also increase the initial period of side effects of breathiness and swallowing difficulties. However, recent analyses of quality-of-life questionnaires in patients undergoing regular injections of botulinum toxin demonstrate that a large proportion of patients have limited relief for relatively short periods due to early breathiness and loss-of-benefit before reinjection. Summary Most medical and surgical approaches to the treatment of spasmodic dysphonia have been aimed at denervation of the laryngeal muscles to block symptom expression in the voice, and have both adverse effects as well as treatment benefits. Research is needed to identify the central neuropathophysiology responsible for the laryngeal muscle spasms in order target treatment towards the central neurological abnormality responsible for producing symptoms. PMID:19337127

Citric Acid Alternative to Nitric Acid Passivation

Science.gov (United States)

Lewis, Pattie L. (Compiler)

2013-01-01

The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

Semi-Preparative Separation of 10 Caffeoylquinic Acid Derivatives Using High Speed Counter-Current Chromatogaphy Combined with Semi-Preparative HPLC from the Roots of Burdock (Arctium lappa L.).

Science.gov (United States)

Zheng, Zhenjia; Wang, Xiao; Liu, Pengli; Li, Meng; Dong, Hongjing; Qiao, Xuguang

2018-02-15

Burdock roots are healthy dietary supplements and a kind of famous traditional Chinese medicine, which contains large amounts of caffeoylquinic acid derivatives. However, little research has been reported on the preparative separation of these compounds from burdock roots. In the present study, a combinative method of HSCCC and semi-preparative HPLC was developed for the semi-preparative separation of caffeoylquinic acid derivatives from the burdock roots. The ethyl acetate extract of burdock roots was first fractionated by MCI macroporous resin chromatography and give three fractions (Fr. 1-3) from the elution of 40% methanol. Then, these three fractions (120 mg) were separately subjected to HSCCC for purification with the solvent system composed of petroleum ether-ethyl acetate-methanol-water at different volume ratios, and the mixtures were further purified by semi-preparative HPLC. As a result, a total of eight known caffeoylquinic acid derivatives including 3- O -caffeoylquinic acid (32.7 mg, 95.7%), 1,5- O - dicaffeoylquinic acid (4.3 mg, 97.2%), 3- O -caffeoylquinic acid methyl ester (12.1 mg, 93.2%), 1,3- O -dicaffeoylquinic acid (42.9 mg, 91.1%), 1,5- O -dicaffeoyl-3- O -(4-maloyl)-quinic acid (4.3 mg, 84.5%), 4,5- O -dicaffeoylquinic acid (5.3 mg, 95.5%), 1,5- O -dicaffeoyl-3- O -succinylquinic acid (8.7 mg, 93.4%), and 1,5- O -dicaffeoyl-4- O -succinylquinic acid (1.7 mg, 91.8%), and two new compounds were obtained. The new compounds were 1,4- O -dicaffeoyl-3-succinyl methyl ester quinic acid (14.6 mg, 96.1%) and 1,5- O -dicaffeoyl-3- O -succinyl methyl ester quinic acid (3.1 mg, 92.6%), respectively. The research indicated that the combination of HSCCC and semi-preparative HPLC is a highly efficient approach for preparative separation of the instability and bioactive caffeoylquinic acid derivatives from natural products.

The reflection of evolving bearing faults in the stator current's extended park vector approach for induction machines

Science.gov (United States)

Corne, Bram; Vervisch, Bram; Derammelaere, Stijn; Knockaert, Jos; Desmet, Jan

2018-07-01

Stator current analysis has the potential of becoming the most cost-effective condition monitoring technology regarding electric rotating machinery. Since both electrical and mechanical faults are detected by inexpensive and robust current-sensors, measuring current is advantageous on other techniques such as vibration, acoustic or temperature analysis. However, this technology is struggling to breach into the market of condition monitoring as the electrical interpretation of mechanical machine-problems is highly complicated. Recently, the authors built a test-rig which facilitates the emulation of several representative mechanical faults on an 11 kW induction machine with high accuracy and reproducibility. Operating this test-rig, the stator current of the induction machine under test can be analyzed while mechanical faults are emulated. Furthermore, while emulating, the fault-severity can be manipulated adaptively under controllable environmental conditions. This creates the opportunity of examining the relation between the magnitude of the well-known current fault components and the corresponding fault-severity. This paper presents the emulation of evolving bearing faults and their reflection in the Extended Park Vector Approach for the 11 kW induction machine under test. The results confirm the strong relation between the bearing faults and the stator current fault components in both identification and fault-severity. Conclusively, stator current analysis increases reliability in the application as a complete, robust, on-line condition monitoring technology.

Anodized aluminum on LDEF: A current status of measurements on chromic acid anodized aluminum

International Nuclear Information System (INIS)

Golden, J.L.

1992-01-01

Chromic acid anodize was used as the exterior coating for aluminum surfaces on LDEF to provide passive thermal control. Chromic acid anodized aluminum was also used as test specimens in thermal control coatings experiments. The following is a compilation and analysis of the data obtained thus far

Anodized aluminum on LDEF: A current status of measurements on chromic acid anodized aluminum

Science.gov (United States)

Golden, Johnny L.

1992-01-01

Chromic acid anodize was used as the exterior coating for aluminum surfaces on LDEF to provide passive thermal control. Chromic acid anodized aluminum was also used as test specimens in thermal control coatings experiments. The following is a compilation and analysis of the data obtained thus far.

A statistical approach to the experimental design of the sulfuric acid leaching of gold-copper ore

Directory of Open Access Journals (Sweden)

Mendes F.D.

2003-01-01

Full Text Available The high grade of copper in the Igarapé Bahia (Brazil gold-copper ore prevents the direct application of the classic cyanidation process. Copper oxides and sulfides react with cyanides in solution, causing a high consumption of leach reagent and thereby raising processing costs and decreasing recovery of gold. Studies have showm that a feasible route for this ore would be a pretreatment for copper minerals removal prior to the cyanidation stage. The goal of this experimental work was to study the experimental conditions required for copper removal from Igarapé Bahia gold-copper ore by sulfuric acid leaching by applying a statistical approach to the experimental design. By using the Plackett Burman method, it was possible to select the variables that had the largest influence on the percentage of copper extracted at the sulfuric acid leaching stage. These were temperature of leach solution, stirring speed, concentration of sulfuric acid in the leach solution and particle size of the ore. The influence of the individual effects of these variables and their interactions on the experimental response were analyzed by applying the replicated full factorial design method. Finally, the selected variables were optimized by the ascending path statistical method, which determined the best experimental conditions for leaching to achieve the highest percentage of copper extracted. Using the optimized conditions, the best leaching results showed a copper extraction of 75.5%.

Fluorescent probes for detection of picric acid explosive: A greener approach

Energy Technology Data Exchange (ETDEWEB)

Chakravarty, Sudesna; Gogoi, Bedanta; Sen Sarma, Neelotpal, E-mail: neelot@iasst.gov.in

2015-09-15

Green materials with advantages of low cost and high sensitivity are important from the perspective of human health, environment and homeland security. Herein, we have reported two cost effective modified biomaterials as fluorophores for detection of Picric acid in aqueous state. The biomaterials Scutellarin–Hispiduloside and Curcumin have been modified with green solvent glycerol for Picric acid detection in aqueous solution. The limit of detection for Picric acid by Scutellarin–Hispiduloside–glycerol and Curcumin–glycerol are 9.1×10{sup −8} M and 6.03×10{sup −8} M respectively. These luminescence based sensors have also been able to detect Picric acid in real samples with high efficiency. The fluorescence quenching efficiency of Scutellarin–Hispiduloside–glycerol has been found to be 99% while that for Curcumin–glycerol, it is 88.9% for 0.5 µM Picric acid in aqueous state. In both the cases, the quenching is governed by FRET between the fluorophore and the quencher and the FRET efficiency has been found to be 0.968 and 0.792 respectively. In addition, both the systems show excellent selectivity towards PA in presence of other nitroaromatic compounds and are also statistically accessible. The utilization of readily available cheap biomaterials without using multistep protocol for synthesis and devoid of any kind of sophisticated equipments for the processs further enhances the utility of the method. - Highlights: • Environmentally benign systems – Scutellarin, Hispiduloside and curcumin with green solvent glycerol – have been used for Picric acid sensing. • The method is simple and cost effective with a detection limit for CIG and CG found to be 9.1×10−8 M and 6.03×10−8 M of PA respectively. • Both the sensing systems were found to be highly selective for Picric acid in the presence of structurally similar compounds. • The quenching occurs by FRET between the fluorophore and the quencher and the FRET efficiency is determined

Effects of Perfluorooctanoic Acid on Metabolic Profiles in Brain and Liver of Mouse Revealed by a High-throughput Targeted Metabolomics Approach

Science.gov (United States)

Yu, Nanyang; Wei, Si; Li, Meiying; Yang, Jingping; Li, Kan; Jin, Ling; Xie, Yuwei; Giesy, John P.; Zhang, Xiaowei; Yu, Hongxia

2016-04-01

Perfluorooctanoic acid (PFOA), a perfluoroalkyl acid, can result in hepatotoxicity and neurobehavioral effects in animals. The metabolome, which serves as a connection among transcriptome, proteome and toxic effects, provides pathway-based insights into effects of PFOA. Since understanding of changes in the metabolic profile during hepatotoxicity and neurotoxicity were still incomplete, a high-throughput targeted metabolomics approach (278 metabolites) was used to investigate effects of exposure to PFOA for 28 d on brain and liver of male Balb/c mice. Results of multivariate statistical analysis indicated that PFOA caused alterations in metabolic pathways in exposed individuals. Pathway analysis suggested that PFOA affected metabolism of amino acids, lipids, carbohydrates and energetics. Ten and 18 metabolites were identified as potential unique biomarkers of exposure to PFOA in brain and liver, respectively. In brain, PFOA affected concentrations of neurotransmitters, including serotonin, dopamine, norepinephrine, and glutamate in brain, which provides novel insights into mechanisms of PFOA-induced neurobehavioral effects. In liver, profiles of lipids revealed involvement of β-oxidation and biosynthesis of saturated and unsaturated fatty acids in PFOA-induced hepatotoxicity, while alterations in metabolism of arachidonic acid suggesting potential of PFOA to cause inflammation response in liver. These results provide insight into the mechanism and biomarkers for PFOA-induced effects.

Examination of the Current Approaches to State-Level Nuclear Security Evaluation

International Nuclear Information System (INIS)

Kim, Chan; Yim, Mansung; Kim, So Young

2014-01-01

An effective global nuclear materials security system will cover all materials, employ international standards and best practices, and reduce risks by reducing weapons-usable nuclear material stocks and the number of locations where they are found. Such a system must also encourage states to accept peer reviews by outside experts in order to demonstrate that effective security is in place. It is thus critically important to create an integrative framework of state-level evaluation of nuclear security as a basis for measuring the level and progress of international effort to secure and control all nuclear materials. There have been studies to represent state-level nuclear security with a quantitative metric. A prime example is the Nuclear Materials Security Index (NMSI) by the Nuclear Threat Initiative (NTI). Another comprehensive study is the State Level Risk Metric by Texas A and M University (TAMU). This paper examines the current methods with respect to their strengths and weaknesses and identifies the directions for future research to improve upon the existing approaches

Role of amino acid supplementation in the prevention of necrotizing enterocolitis in preterm neonates - a review of current evidences.

Science.gov (United States)

Garg, Bhawan Deep; Kabra, Nandkishor S

2018-09-01

Necrotizing enterocolitis (NEC) is one of the most common acute and fatal gastrointestinal emergency in very low birth weight (VLBW) preterm neonates with mortality range from 15 to 30%. NEC is likely due to multifactorial process such as oxidative injury, ischemic necrosis, and over-reactive inflammatory response to intestinal microbes. To evaluate the role of amino acid supplementation for reduction of neonatal NEC in preterm neonates. The literature search was done for various randomized control trial (RCT) by searching the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, Web of Science, Scopus, Index Copernicus, African Index Medicus (AIM), Thomson Reuters (ESCI), Chemical Abstracts Service (CAS) and other database. This review included 15 RCTs that fulfilled inclusion criteria. The total neonates enrolled in these different RCT are 3424 (amino acid group 1711 and control 1713). Almost all participating neonates were of VLBW or extremely low birth weight (ELBW). In two trials, birth weight was between 1500-2000 grams. The intervention was started within first few days after birth and continued up to 30th day of postnatal age in most of the trials. In two trials, intervention was continued up to 120th day of postnatal age. Arginine, glutamine and N-acetyl cysteine (NAC) were used at the dose of 1.5 mol/kg/day (261 mg/kg/day), 0.3 grams/kg/day and 16-32 mg/kg/day, respectively. Role of amino acid in the prevention of neonatal NEC is not exclusively supported by the current evidence. Only three studies were able to show reduction in the incidence of NEC with amino acid supplementation (arginine, glutamine), and the remaining studies did not report any positive effect. Amino acid supplementation was not associated with significant reduction in mortality due to any causes. However, arginine supplementation was associated with significant reduction in mortality due to NEC. Two studies on glutamine were reported significant reduction in

Assembly of barcode-like nucleic acid nanostructures.

Science.gov (United States)

Wang, Pengfei; Tian, Cheng; Li, Xiang; Mao, Chengde

2014-10-15

Barcode-like (BC) nanopatterns from programmed self-assembly of nucleic acids (DNA and RNA) are reported. BC nanostructures are generated by the introduction of open spaces at selected sites to an otherwise closely packed, plain, rectangle nucleic acid nanostructure. This strategy is applied to nanostructures assembled from both origami approach and single stranded tile approach. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

'Leak Current' correction for critical current measurement of no-insulation HTS coil

Energy Technology Data Exchange (ETDEWEB)

Song, Jung Bin [Laboratoire National des Champs Magnétiques Intenses, CNRS, Grenoble (France); Hahn, Seung Yong [Dept. of Electrical and Computer Engineering, Seoul National University, Seoul (Korea, Republic of)

2017-06-15

Discrepancy between a power supply current and an actual “spiral” coil current makes the conventional 4-probe measurement of a critical current (I{sub c}) of a no-insulation (NI) high temperature superconductor (HTS) coil inaccurate and time-consuming. This paper presents a fast and accurate approach for I{sub c} measurement of NI HTS coils. With an NI HTS coil energized at a constant ramping rate, a complete analytic expression for the spiral coil current was obtained from a first-order partial differential equation that derived from an equivalent circuit model of the NI coil. From the analytic solution, both spiral coil current and radial leak current can be obtained simultaneously, which enables fast and accurate measurement of the NI coil I{sub c}. To verify the proposed approach, an NI double-pancake (DP) coil, wound with GdBCO tapes of 6 mm × 0.1 mm, was constructed and its Ic was repeatedly measured with various ramping rates in a bath of liquid nitrogen at 77 K. The measured results agreed well with the calculated ones, which validates the proposed approach to measure I{sub c} of an NI HTS coil.

Bile acids: regulation of apoptosis by ursodeoxycholic acid.

Science.gov (United States)

Amaral, Joana D; Viana, Ricardo J S; Ramalho, Rita M; Steer, Clifford J; Rodrigues, Cecília M P

2009-09-01

Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been related to membrane damage, but also to nondetergent effects, such as oxidative stress and apoptosis. Strikingly, hydrophilic ursodeoxycholic acid (UDCA), and its taurine-conjugated form (TUDCA), show profound cytoprotective properties. Indeed, these molecules have been described as potent inhibitors of classic pathways of apoptosis, although their precise mode of action remains to be clarified. UDCA, originally used for cholesterol gallstone dissolution, is currently considered the first choice therapy for several forms of cholestatic syndromes. However, the beneficial effects of both UDCA and TUDCA have been tested in other experimental pathological conditions with deregulated levels of apoptosis, including neurological disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Here, we review the role of bile acids in modulating the apoptosis process, emphasizing the anti-apoptotic effects of UDCA and TUDCA, as well as their potential use as novel and alternate therapeutic agents for the treatment of apoptosis-related diseases.

Synthesis of biorefinery networks using a superstructure optimization based approach

DEFF Research Database (Denmark)

Bertran, Maria-Ona; Anaya-Reza, Omar; Lopez-Arenas, Maria Teresa

Petroleum is currently the primary raw material for the production of fuels and chemicals. Consequently, our society is highly dependent on fossil non-renewable resources. However, renewable raw materials are recently receiving increasing interest for the production of chemicals and fuels, so a n...... of the proposed approach is shown through a practical case study for the production of valuable products (i.e. lysine and lactic acid) from sugarcane molasses; these alternatives are considered with respect to availability and demands in Mexico [4]....

Beyond (eco)design : Current approaches to sustainable packaging design

NARCIS (Netherlands)

Wever, R.

2014-01-01

Packaging has always received a lot of attention within the field of design for sustainability. The classical approach has been to mainly focus on reducing the impact of the packaging. This approach stems from the ill-informed position that packaging is superfluous, or at best there only for

Next-generation sequencing approaches for improvement of lactic acid bacteria-fermented plant-based beverages

Directory of Open Access Journals (Sweden)

Jordyn Bergsveinson

2017-01-01

Full Text Available Plant-based beverages and milk alternatives produced from cereals and legumes have grown in popularity in recent years due to a range of consumer concerns over dairy products. These plant-based products can often have undesirable physiochemical properties related to flavour, texture, and nutrient availability and/or deficiencies. Lactic acid bacteria (LAB fermentation offers potential remediation for many of these issues, and allows consumers to retain their perception of the resultant products as natural and additive-free. Using next-generation sequencing (NGS or omics approaches to characterize LAB isolates to find those that will improve properties of plant-based beverages is the most direct way to product improvement. Although NGS/omics approaches have been extensively used for selection of LAB for use in the dairy industry, a comparable effort has not occurred for selecting LAB for fermenting plant raw substrates, save those used in producing wine and certain types of beer. Here we review the few and recent applications of NGS/omics to profile and improve LAB fermentation of various plant-based substrates for beverage production. We also identify specific issues in the production of various LAB fermented plant-based beverages that such NGS/omics applications have the power to resolve.

Modeling radiation loads in the ILC main linac and a novel approach to treat dark current

Energy Technology Data Exchange (ETDEWEB)

Mokhov, Nilolai V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Rakhno, Igor L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Tropin, Igor S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2017-09-11

Electromagnetic and hadron showers generated by electrons of dark current (DC) can represent a significant radiation threat to the ILC linac equipment and personnel. In this study, a commissioning scenario is analysed which is considered as the worst-case scenario for the main linac regarding the DC contribution to the radiation environment in the tunnel. A normal operation scenario is analysed as well. An emphasis is made on radiation load to sensitive electronic equipment—cryogenic thermometers inside the cryomodules. Prompt and residual dose rates in the ILC main linac tunnels were also calculated in these new high-statistics runs. A novel approach was developed—as a part of general purpose Monte Carlo code MARS15—to model generation, acceleration and transport of DC electrons in electromagnetic fields inside SRF cavities. Comparisons were made with a standard approach when a set of pre-calculated DC electron trajectories is used, with a proper normalization, as a source for Monte Carlo modelling. Results of MARS15 Monte Carlo calculations, performed for the current main linac tunnel design, reveal that the peak absorbed dose in the cryogenic thermometers in the main tunnel for 20 years of operation is about 0.8 MGy. The calculated contact residual dose on cryomodules and tunnel walls in the main tunnel for typical irradiation and cooling conditions is 0.1 and 0.01 mSv/hr, respectively.

Therapeutic options in pediatric non alcoholic fatty liver disease: current status and future directions

Directory of Open Access Journals (Sweden)

Vajro Pietro

2012-10-01

Full Text Available Abstract The epidemics of overweight and obesity has resulted in a significant increase of non alcoholic fatty liver disease (NAFLD, a potentially progressive condition. Currently, obesity related hepatopathy represents therefore the main cause of pediatric chronic liver disease. The first choice treatment at all ages is weight loss and/or lifestyle changes, however compliance is very poor and a pharmacological approach has become necessary. In the present article we present a systematic literature review focusing on established pediatric NALFD drugs (ursodeoxycholic acid, insulin sensitizers, and antioxidants and on innovative therapeutic options as well. Regarding the former ones, a pediatric pilot study highlighted that ursodeoxycholic acid is not efficient on transaminases levels and bright liver. Similarly, a recent large scale, multicenter randomized clinical trial (TONIC study showed that also insulin sensitizers and antioxidant vitamin E have scarce effects on serum transaminase levels. Among a large series of novel therapeutic approaches acting on recently proposed different pathomechanisms, probiotics seem hitherto the most interesting and reasonable option for their safety and tolerability. Toll-like receptors modifiers, Pentoxifylline, and Farnesoid X receptors agonists have been still poorly investigated, and will need further studies before becoming possible promising innovative therapeutic strategies.

Agulhas Current variability determined from space: a multi-sensor approach

CSIR Research Space (South Africa)

Rouault, M

2011-11-01

Full Text Available to the Doppler shift signal, the ASAR surface current velocities are able to consistently highlight regions of strong current and shear. The synaptic nature and relatively high resolution of ASAR acquisitions make the ASAR derived current velocities a good...

Teaching Acid/Base Physiology in the Laboratory

Science.gov (United States)

Friis, Ulla G.; Plovsing, Ronni; Hansen, Klaus; Laursen, Bent G.; Wallstedt, Birgitta

2010-01-01

Acid/base homeostasis is one of the most difficult subdisciplines of physiology for medical students to master. A different approach, where theory and practice are linked, might help students develop a deeper understanding of acid/base homeostasis. We therefore set out to develop a laboratory exercise in acid/base physiology that would provide…

Semi-Preparative Separation of 10 Caffeoylquinic Acid Derivatives Using High Speed Counter-Current Chromatogaphy Combined with Semi-Preparative HPLC from the Roots of Burdock (Arctium lappa L.

Directory of Open Access Journals (Sweden)

Zhenjia Zheng

2018-02-01

Full Text Available Burdock roots are healthy dietary supplements and a kind of famous traditional Chinese medicine, which contains large amounts of caffeoylquinic acid derivatives. However, little research has been reported on the preparative separation of these compounds from burdock roots. In the present study, a combinative method of HSCCC and semi-preparative HPLC was developed for the semi-preparative separation of caffeoylquinic acid derivatives from the burdock roots. The ethyl acetate extract of burdock roots was first fractionated by MCI macroporous resin chromatography and give three fractions (Fr. 1–3 from the elution of 40% methanol. Then, these three fractions (120 mg were separately subjected to HSCCC for purification with the solvent system composed of petroleum ether-ethyl acetate-methanol-water at different volume ratios, and the mixtures were further purified by semi-preparative HPLC. As a result, a total of eight known caffeoylquinic acid derivatives including 3-O-caffeoylquinic acid (32.7 mg, 95.7%, 1,5-O- dicaffeoylquinic acid (4.3 mg, 97.2%, 3-O-caffeoylquinic acid methyl ester (12.1 mg, 93.2%, 1,3-O-dicaffeoylquinic acid (42.9 mg, 91.1%, 1,5-O-dicaffeoyl-3-O-(4-maloyl-quinic acid (4.3 mg, 84.5%, 4,5-O-dicaffeoylquinic acid (5.3 mg, 95.5%, 1,5-O-dicaffeoyl-3-O-succinylquinic acid (8.7 mg, 93.4%, and 1,5-O-dicaffeoyl-4-O-succinylquinic acid (1.7 mg, 91.8%, and two new compounds were obtained. The new compounds were 1,4-O-dicaffeoyl-3-succinyl methyl ester quinic acid (14.6 mg, 96.1% and 1,5-O-dicaffeoyl-3-O-succinyl methyl ester quinic acid (3.1 mg, 92.6%, respectively. The research indicated that the combination of HSCCC and semi-preparative HPLC is a highly efficient approach for preparative separation of the instability and bioactive caffeoylquinic acid derivatives from natural products.

Current approaches in atrial fibrillation treatment

Directory of Open Access Journals (Sweden)

Cenk Sarı

2014-09-01

Full Text Available Atrial fibrillation (AF is the most common sustained arrhythmia encountered in clinical practice. Its incidence increases with age. AF is classified into subtypes according to the duration and/or able to provide sinus rhytym. İnitially, patients should be evaluated for rhythm or rate control for appropriate treatment. Second stage of strategy aimed to investigate the feasibility of anticoagulation therapy. Recently, due to the progress made in treatment with rhythm control and anticoagulation therapy, either American or European guidelines have been renovated. These developments have taken place in the newly published guide. In this article, the current change in the management of AF is discussed.

The bile acids, deoxycholic acid and ursodeoxycholic acid, regulate colonic epithelial wound healing.

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Mroz, Magdalena S; Lajczak, Natalia K; Goggins, Bridie J; Keely, Simon; Keely, Stephen J

2018-03-01

The intestinal epithelium constitutes an innate barrier which, upon injury, undergoes self-repair processes known as restitution. Although bile acids are known as important regulators of epithelial function in health and disease, their effects on wound healing processes are not yet clear. Here we set out to investigate the effects of the colonic bile acids, deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA), on epithelial restitution. Wound healing in T 84 cell monolayers grown on transparent, permeable supports was assessed over 48 h with or without bile acids. Cell migration was measured in Boyden chambers. mRNA and protein expression were measured by RT-PCR and Western blotting. DCA (50-150 µM) significantly inhibited wound closure in cultured epithelial monolayers and attenuated cell migration in Boyden chamber assays. DCA also induced nuclear accumulation of the farnesoid X receptor (FXR), whereas an FXR agonist, GW4064 (10 µM), inhibited wound closure. Both DCA and GW4064 attenuated the expression of CFTR Cl - channels, whereas inhibition of CFTR activity with either CFTR- inh -172 (10 µM) or GlyH-101 (25 µM) also prevented wound healing. Promoter/reporter assays revealed that FXR-induced downregulation of CFTR is mediated at the transcriptional level. In contrast, UDCA (50-150 µM) enhanced wound healing in vitro and prevented the effects of DCA. Finally, DCA inhibited and UDCA promoted mucosal healing in an in vivo mouse model. In conclusion, these studies suggest bile acids are important regulators of epithelial wound healing and are therefore good targets for development of new drugs to modulate intestinal barrier function in disease treatment. NEW & NOTEWORTHY The secondary bile acid, deoxycholic acid, inhibits colonic epithelial wound healing, an effect which appears to be mediated by activation of the nuclear bile acid receptor, FXR, with subsequent downregulation of CFTR expression and activity. In contrast, ursodeoxycholic acid promotes

Asthma and obesity in children: current evidence and potential systems biology approaches.

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Frey, U; Latzin, P; Usemann, J; Maccora, J; Zumsteg, U; Kriemler, S

2015-01-01

Both obesity and asthma are highly prevalent, complex diseases modified by multiple factors. Genetic, developmental, lung mechanical, immunological and behavioural factors have all been suggested as playing a causal role between the two entities; however, their complex mechanistic interactions are still poorly understood and evidence of causality in children remains scant. Equally lacking is evidence of effective treatment strategies, despite the fact that imbalances at vulnerable phases in childhood can impact long-term health. This review is targeted at both clinicians frequently faced with the dilemma of how to investigate and treat the obese asthmatic child and researchers interested in the topic. Highlighting the breadth of the spectrum of factors involved, this review collates evidence regarding the investigation and treatment of asthma in obese children, particularly in comparison with current approaches in 'difficult-to-treat' childhood asthma. Finally, the authors propose hypotheses for future research from a systems-based perspective. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Standard and biological treatment in large vessel vasculitis: guidelines and current approaches.

Science.gov (United States)

Muratore, Francesco; Pipitone, Nicolò; Salvarani, Carlo

2017-04-01

Giant cell arteritis and Takayasu arteritis are the two major forms of idiopathic large vessel vasculitis. High doses of glucocorticoids are effective in inducing remission in both conditions, but relapses and recurrences are common, requiring prolonged glucocorticoid treatment with the risk of the related adverse events. Areas covered: In this article, we will review the standard and biological treatment strategies in large vessel vasculitis, and we will focus on the current approaches to these diseases. Expert commentary: The results of treatment trials with conventional immunosuppressive agents such as methotrexate, azathioprine, mycophenolate mofetil, and cyclophosphamide have overall been disappointing. TNF-α blockers are ineffective in giant cell arteritis, while observational evidence and a phase 2 randomized trial support the use of tocilizumab in relapsing giant cell arteritis. Observational evidence strongly supports the use of anti-TNF-α agents and tocilizumab in Takayasu patients with relapsing disease. However biological agents are not curative, and relapses remain common.

Impact of Bio-Based Plastics on Current Recycling of Plastics

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Luc Alaerts

2018-05-01

Full Text Available Bio-based plastics are increasingly appearing in a range of consumption products, and after use they often end up in technical recycling chains. Bio-based plastics are different from fossil-based ones and could disturb the current recycling of plastics and hence inhibit the closure of plastic cycles, which is undesirable given the current focus on a transition towards a circular economy. In this paper, this risk has been assessed via three elaborated case studies using data and information retrieved through an extended literature search. No overall risks were revealed for bio-based plastics as a group; rather, every bio-based plastic is to be considered as a potential separate source of contamination in current recycling practices. For PLA (polylactic acid, a severe incompatibility with PET (polyethylene terephthalate recycling is known; hence, future risks are assessed by measuring amounts of PLA ending up in PET waste streams. For PHA (polyhydroxy alkanoate there is no risk currently, but it will be crucial to monitor future application development. For PEF (polyethylene furanoate, a particular approach for contamination-related issues has been included in the upcoming market introduction. With respect to developing policy, it is important that any introduction of novel plastics is well guided from a system perspective and with a particular eye on incompatibilities with current and upcoming practices in the recycling of plastics.

Methods for preparation of deuterated amino acids

International Nuclear Information System (INIS)

Pshenichnikova, A.B.; Karnaukhova, E.N.; Zvonkova, E.N.

1995-01-01

The current state and prospects for the use of amino acids labeled with stable isotopes are considered. Methods for the preparation of deuterated amino acids, including synthetic, chemicoenzymatic, and biosynthetic ones, and deuterium exchange reactions are summarized. Problems in the preparation of optically pure amino acids are discussed. 120 refs., 15 figs

GROUNDWATER IMPACTED BY ACID MINE DRAINAGE

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The generation and release of acidic, metal-rich water from mine wastes continues to be an intractable environmental problem. Although the effects of acid mine drainage (AMD) are most evident in surface waters, there is an obvious need for developing cost-effective approaches fo...

The role of omega-3 polyunsaturated fatty acids eicosapentaenoic and docosahexaenoic acids in the treatment of major depression and Alzheimer's disease: Acting separately or synergistically?

Science.gov (United States)

Song, Cai; Shieh, Chu-Hsin; Wu, Yi-Shyuan; Kalueff, Allan; Gaikwad, Siddharth; Su, Kuan-Pin

2016-04-01

Omega-3 polyunsaturated fatty acids (n-3-PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may improve or prevent some psychiatric and neurodegenerative diseases in both experimental and clinical studies. As important membrane components, these PUFAs benefit brain health by modulating neuroimmune and apoptotic pathways, changing membrane function and/or competing with n-6 PUFAs, the precursors of inflammatory mediators. However, the exact role of each fatty acid in neuroimmune modulation and neurogenesis, the interaction between EPA and DHA, and the best EPA:DHA ratios for improving brain disorders, remain unclear. It is also unknown whether EPA, as a DHA precursor, acts directly or via DHA. Here, we discuss recent evidence of EPA and DHA effects in the treatment of major depression and Alzheimer's disease, as well as their potential synergistic action on anti-inflammatory, antioxidant and neurotrophic processes in the brain. We further analyze the cellular and molecular mechanisms by which EPA, DHA or their combination may benefit these diseases. We also outline the limitations of current studies and suggest new genetic models and novel approaches to overcome these limitations. Finally, we summarize future strategies for translational research in this field. Copyright © 2016 Elsevier B.V. All rights reserved.

Stimulation of apical sodium-dependent bile acid transporter expands the bile acid pool and generates bile acids with positive feedback properties.

Science.gov (United States)

Rudling, Mats; Bonde, Ylva

2015-01-01

Bile acid synthesis has been considered a prototype for how a physiological process is controlled by end product feedback inhibition. By this feedback inhibition, bile acid concentrations are kept within safe ranges. However, careful examination of published rodent data strongly suggests that bile acid synthesis is also under potent positive feedback control by hydrophilic bile acids. Current concepts on the regulation of bile acid synthesis are derived from mouse models. Recent data have shown that mice have farnesoid X receptor (FXR) antagonistic bile acids capable of quenching responses elicited by FXR agonistic bile acids. This is important to recognize to understand the regulation of bile acid synthesis in the mouse, and in particular to clarify if mouse model findings are valid also in the human situation. In addition to classic end product feedback inhibition, regulation of bile acid synthesis in the mouse largely appears also to be driven by changes in hepatic levels of murine bile acids such as α- and β-muricholic acids. This has not been previously recognized. Stimulated bile acid synthesis or induction of the apical sodium-dependent bile acid transporter in the intestine, increase the availability of chenodeoxycholic acid in the liver, thereby promoting hepatic conversion of this bile acid into muricholic acids. Recognition of these mechanisms is essential for understanding the regulation of bile acid synthesis in the mouse, and for our awareness of important species differences in the regulation of bile acid synthesis in mice and humans. 2015 S. Karger AG, Basel.

New food approaches to reduce and/or eliminate increased gastric acidity related to gastroesophageal pathologies.

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Langella, Ciro; Naviglio, Daniele; Marino, Marina; Calogero, Armando; Gallo, Monica

2018-03-22

Gastroesophageal reflux disease is very common in industrialized countries and rapidly and significantly increasing even in developing countries. The approach in this study is one not commonly found to date in the scientific literature. To assess the ability of reduced-carbohydrate diets and foods that are enriched with acid potential of hydrogen (pH; lemon and tomato) to quickly and exponentially reduce symptoms that are related to conditions such as gastritis and gastroesophageal reflux and unrelated to Helicobacter pylori. After the administration of an anamnestic test, 130 patients were selected including 73 women and 57 men, 21 to 67 y, and with a gastritis diagnosis for 92 patients (56 women, 36 men) and reflux gastritis for 38 patients (17 women, 21 men). Study participants followed three dietary treatments in succession. Each treatment lasted 2 wk and treatments were separated by 2 wk of washout. The patients followed a diet that consisted primarily of proteins and fats and included the exponential reduction of glycides (simple and complex). In addition, the treatment provided for the daily intake of the juice of two lemons and approximately 100 g of fresh orange tomato without seeds eaten either raw or cooked and peeled. During treatment and at the end of 2 wk of treatment, the patients reported significant improvements including an almost total disappearance of symptoms that were related to the disease in question. This study shows that a carbohydrate-free diet and/or highly hypoglycidal diet that is enriched with acid pH foods appears to lead to a decrease in the pH of the gastric contents, thus inhibiting the further production of hydrochloric acid with a reduction or disappearance of heartburn symptoms that are typical of gastroesophageal diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

Tranexamic acid for the prevention and management of orthopedic surgical hemorrhage: current evidence

Science.gov (United States)

Kim, Christopher; Park, Sam Si-Hyeong; Davey, J Roderick

2015-01-01

Total joint arthroplasty can be associated with major blood loss and require subsequent blood transfusions for postoperative anemia. Measures to effectively and safely decrease blood loss and reduce the need for blood transfusions would help improve patient safety and lower health care costs. A possible pharmacological option to reduce surgical blood loss in total joint arthroplasty is the use of tranexamic acid. Abundant literature has shown that intravenous and/or topical administration of tranexamic acid is effective in reducing blood loss and blood transfusions, with no increased risk of venous thromboembolic events or other complications. PMID:26345147

Dynamical Approach to Multiequilibria Problems for Mixtures of Acids and Their Conjugated Bases

Science.gov (United States)

Glaser, Rainer E.; Delarosa, Marco A.; Salau, Ahmed Olasunkanmi; Chicone, Carmen

2014-01-01

Mathematical methods are described for the determination of steady-state concentrations of all species in multiequilibria systems consisting of several acids and their conjugated bases in aqueous solutions. The main example consists of a mixture of a diprotic acid H[subscript 2]A, a monoprotic acid HB, and their conjugate bases. The reaction…

OPTIMIZATION OF VEGETABLE WASTES FOR LACTIC ACID PRODUCTION: A LABORATORY SCALE APPROACH

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Sailaja Daharbha

2015-04-01

Full Text Available Vegetables wastes are organic materials which are not utilized as vegetables and are discarded at all stages of production, processing and marketing. These wastes form a major part of municipal solid wastes and are cause of foul smell and growth of microorganisms due to their high organic contents. The vegetable wastes can be utilized in many different ways to produces different products. We have shown that they can be utilized for production of lactic acid using anaerobic digestion. The 2nd day was the optimum day for recovery of lactic acid while 1:1 ratio of slurry and water was found to the best ratio for production of lactic acid from vegetable wastes. Effect of salts on lactic acid was also studied and it was found that the production decreased in all the concentrations of salts.

Current Advance and Future Prospects of Tissue Engineering Approach to Dentin/Pulp Regenerative Therapy

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Ting Gong

2016-01-01

Full Text Available Recent advances in biomaterial science and tissue engineering technology have greatly spurred the development of regenerative endodontics. This has led to a paradigm shift in endodontic treatment from simply filling the root canal systems with biologically inert materials to restoring the infected dental pulp with functional replacement tissues. Currently, cell transplantation has gained increasing attention as a scientifically valid method for dentin-pulp complex regeneration. This multidisciplinary approach which involves the interplay of three key elements of tissue engineering—stem cells, scaffolds, and signaling molecules—has produced an impressive number of favorable outcomes in preclinical animal studies. Nevertheless, many practical hurdles need to be overcome prior to its application in clinical settings. Apart from the potential health risks of immunological rejection and pathogenic transmission, the lack of a well-established banking system for the isolation and storage of dental-derived stem cells is the most pressing issue that awaits resolution and the properties of supportive scaffold materials vary across different studies and remain inconsistent. This review critically examines the classic triad of tissue engineering utilized in current regenerative endodontics and summarizes the possible techniques developed for dentin/pulp regeneration.

Current Advance and Future Prospects of Tissue Engineering Approach to Dentin/Pulp Regenerative Therapy

Science.gov (United States)

Gong, Ting; Heng, Boon Chin; Lo, Edward Chin Man; Zhang, Chengfei

2016-01-01

Recent advances in biomaterial science and tissue engineering technology have greatly spurred the development of regenerative endodontics. This has led to a paradigm shift in endodontic treatment from simply filling the root canal systems with biologically inert materials to restoring the infected dental pulp with functional replacement tissues. Currently, cell transplantation has gained increasing attention as a scientifically valid method for dentin-pulp complex regeneration. This multidisciplinary approach which involves the interplay of three key elements of tissue engineering—stem cells, scaffolds, and signaling molecules—has produced an impressive number of favorable outcomes in preclinical animal studies. Nevertheless, many practical hurdles need to be overcome prior to its application in clinical settings. Apart from the potential health risks of immunological rejection and pathogenic transmission, the lack of a well-established banking system for the isolation and storage of dental-derived stem cells is the most pressing issue that awaits resolution and the properties of supportive scaffold materials vary across different studies and remain inconsistent. This review critically examines the classic triad of tissue engineering utilized in current regenerative endodontics and summarizes the possible techniques developed for dentin/pulp regeneration. PMID:27069484

Nanoparticles with high payloads of pipemidic acid, a poorly soluble crystalline drug: drug-initiated polymerization and self-assembly approach

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Elisabetta Pancani

2018-05-01

Full Text Available Nowadays, biodegradable polymers such as poly(lactic acid (PLA, poly(D,L-lactic-co-glycolic acid (PLGA and poly(ε-caprolactone (PCL remain the most common biomaterials to produce drug-loaded nanoparticles (NPs. Pipemidic acid (PIP is a poorly soluble antibiotic with a strong tendency to crystallize. PIP incorporation in PLA/PLGA NPs was challenging because of PIP crystals formation and burst release. As PIP had a poor affinity for the NPs, an alternative approach to encapsulation was used, consisting in coupling PIP to PCL. Thus, a PCL–PIP conjugate was successfully synthesized by an original drug-initiated polymerization in a single step without the need of catalyst. PCL–PIP was characterized by NMR, IR, SEC and mass spectrometry. PCL–PIP was used to prepare self-assembled NPs with PIP contents as high as 27% (w/w. The NPs were characterized by microscopy, DLS, NTA and TRPS. This study paves the way towards the production of NPs with high antibiotic payloads by drug-initiated polymerization. Further studies will deal with the synthesis of novel polymer–PIP conjugates with ester bonds between the drug and PCL. PIP can be considered as a model drug and the strategy developed here could be extended to other challenging antibiotics or anticancer drugs and employed to efficiently incorporate them in NPs. KEY WORDS: Pipemidic acid, Nanoparticle, Antibiotic, Nanoprecipitation, Crystalline drug, Drug-initiated   polymerization

Off-equatorial current-driven instabilities ahead of approaching dipolarization fronts

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Zhang, Xu; Angelopoulos, V.; Pritchett, P. L.; Liu, Jiang

2017-05-01

Recent kinetic simulations have revealed that electromagnetic instabilities near the ion gyrofrequency and slightly away from the equatorial plane can be driven by a current parallel to the magnetic field prior to the arrival of dipolarization fronts. Such instabilities are important because of their potential contribution to global electromagnetic energy conversion near dipolarization fronts. Of the several instabilities that may be consistent with such waves, the most notable are the current-driven electromagnetic ion cyclotron instability and the current-driven kink-like instability. To confirm the existence and characteristics of these instabilities, we used observations by two Time History of Events and Macroscale Interactions during Substorms satellites, one near the neutral sheet observing dipolarization fronts and the other at the boundary layer observing precursor waves and currents. We found that such instabilities with monochromatic signatures are rare, but one of the few cases was selected for further study. Two different instabilities, one at about 0.3 Hz and the other at a much lower frequency, 0.02 Hz, were seen in the data from the off-equatorial spacecraft. A parallel current attributed to an electron beam coexisted with the waves. Our instability analysis attributes the higher-frequency instability to a current-driven ion cyclotron instability and the lower frequency instability to a kink-like instability. The current-driven kink-like instability we observed is consistent with the instabilities observed in the simulation. We suggest that the currents needed to excite these low-frequency instabilities are so intense that the associated electron beams are easily thermalized and hence difficult to observe.

Econometric modelling of Serbian current account determinants: Jackknife Model Averaging approach

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Petrović Predrag

2014-01-01

Full Text Available This research aims to model Serbian current account determinants for the period Q1 2002 - Q4 2012. Taking into account the majority of relevant determinants, using the Jackknife Model Averaging approach, 48 different models have been estimated, where 1254 equations needed to be estimated and averaged for each of the models. The results of selected representative models indicate moderate persistence of the CA and positive influence of: fiscal balance, oil trade balance, terms of trade, relative income and real effective exchange rates, where we should emphasise: (i a rather strong influence of relative income, (ii the fact that the worsening of oil trade balance results in worsening of other components (probably non-oil trade balance of CA and (iii that the positive influence of terms of trade reveals functionality of the Harberger-Laursen-Metzler effect in Serbia. On the other hand, negative influence is evident in case of: relative economic growth, gross fixed capital formation, net foreign assets and trade openness. What particularly stands out is the strong effect of relative economic growth that, most likely, reveals high citizens' future income growth expectations, which has negative impact on the CA.

Feasibility of the current-duration approach to studying human fecundity

DEFF Research Database (Denmark)

Slama, Rémy; Ducot, Béatrice; Carstensen, Lisbeth

2006-01-01

of unprotected intercourse was defined for 69 women (5.7%). An additional 15 women (1.2%) were planning to start trying to become pregnant within the next 6 months. Parametric methods allowed, based on current duration of unprotected intercourse, estimation of fecundity as if the couples had been followed...... up (current-duration design). To illustrate the feasibility of the current-duration design, we contacted a random sample of 1204 French women age 18 to 44 years in 2004 and recruited those who were currently having unprotected sexual intercourse. The current duration since the beginning...... prospectively. The estimated proportion of couples not pregnant after 12 months of unprotected intercourse was 34% (95% confidence interval [CI] = 15-54%). The accelerated-failure time model allows study of the influence of environmental factors on fecundity. As an illustration, tobacco smoking by the woman...

G-protein-coupled receptors for free fatty acids

DEFF Research Database (Denmark)

Milligan, Graeme; Ulven, Trond; Murdoch, Hannah

2014-01-01

of these receptors. However, ongoing clinical trials of agonists of free fatty acid receptor 1 suggest that this receptor and other receptors for free fatty acids may provide a successful strategy for controlling hyperglycaemia and providing novel approaches to treat diabetes. Receptors responsive to free fatty acid...

Nontargeted LC–MS Metabolomics Approach for Metabolic Profiling of Plasma and Urine from Pigs Fed Branched Chain Amino Acids for Maximum Growth Performance

DEFF Research Database (Denmark)

Assadi Soumeh, Elham; Hedemann, Mette Skou; Poulsen, Hanne Damgaard

2016-01-01

The metabolic response in plasma and urine of pigs when feeding an optimum level of branched chain amino acids (BCAAs) for best growth performance is unknown. The objective of the current study was to identify the metabolic phenotype associated with the BCAAs intake level that could be linked to ...

Lightweight, durable lead-acid batteries

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Lara-Curzio, Edgar; An, Ke; Kiggans, Jr., James O; Dudney, Nancy J; Contescu, Cristian I; Baker, Frederick S; Armstrong, Beth L

2013-05-21

A lightweight, durable lead-acid battery is disclosed. Alternative electrode materials and configurations are used to reduce weight, to increase material utilization and to extend service life. The electrode can include a current collector having a buffer layer in contact with the current collector and an electrochemically active material in contact with the buffer layer. In one form, the buffer layer includes a carbide, and the current collector includes carbon fibers having the buffer layer. The buffer layer can include a carbide and/or a noble metal selected from of gold, silver, tantalum, platinum, palladium and rhodium. When the electrode is to be used in a lead-acid battery, the electrochemically active material is selected from metallic lead (for a negative electrode) or lead peroxide (for a positive electrode).

Glutamic acid and folic acid production in aerobic and anaerobic probiotics

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Zohre Taghi Abadi

2018-03-01

Full Text Available Introduction:From an industrial application or commercial point of view, glutamic acid is one of the most important amino acids and its microbial production has been reported from some bacteria. Regarding the role of probiotics to modulate human health and the ever-increasing demand of prebiotics in the food industry, in the current study, production of glutamic acid and folic acid from three probiotic bacteria (Bifidobacterium, Bifidobacterium bifidum, Sporolactobacillus was evaluated for the first time. Materials and methods: MRS broth and exclusive media was used for probiotic culture. The glutamic acid was identified using thin-layer chromatography and folic acid production was measured by folate kit. Each bacterium in terms of quality and quantity were measured by high pressure liquid chromatography. Results: Production of glutamic acid confirmed is based on the thin layer chromatography analysis and high pressure liquid chromatography results. In addition, it was observed that all three probiotics produce folic acid. The prevalence of folate in Bifidobacterium was measured as 315 mg/ml that was more than two other bacteria. Discussion and conclusion: To the best of our knowledge, this is the first report of microbial production of glutamic acid and folate from the probiotic bacteria. These beneficial bacteria can be used as a good source for mass production of these valuable compounds.

An adaptive mesh refinement approach for average current nodal expansion method in 2-D rectangular geometry

International Nuclear Information System (INIS)

Poursalehi, N.; Zolfaghari, A.; Minuchehr, A.

2013-01-01

Highlights: ► A new adaptive h-refinement approach has been developed for a class of nodal method. ► The resulting system of nodal equations is more amenable to efficient numerical solution. ► The benefit of the approach is reducing computational efforts relative to the uniform fine mesh modeling. ► Spatially adaptive approach greatly enhances the accuracy of the solution. - Abstract: The aim of this work is to develop a spatially adaptive coarse mesh strategy that progressively refines the nodes in appropriate regions of domain to solve the neutron balance equation by zeroth order nodal expansion method. A flux gradient based a posteriori estimation scheme has been utilized for checking the approximate solutions for various nodes. The relative surface net leakage of nodes has been considered as an assessment criterion. In this approach, the core module is called in by adaptive mesh generator to determine gradients of node surfaces flux to explore the possibility of node refinements in appropriate regions and directions of the problem. The benefit of the approach is reducing computational efforts relative to the uniform fine mesh modeling. For this purpose, a computer program ANRNE-2D, Adaptive Node Refinement Nodal Expansion, has been developed to solve neutron diffusion equation using average current nodal expansion method for 2D rectangular geometries. Implementing the adaptive algorithm confirms its superiority in enhancing the accuracy of the solution without using fine nodes throughout the domain and increasing the number of unknown solution. Some well-known benchmarks have been investigated and improvements are reported

Cough in Children: Current Approaches to the Treatment

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O.O. Rechkina

2016-03-01

Full Text Available Introduction. Cough is one of the most common symptoms in the practice of doctors of various specialties, including pediatricians. Cough treatment should be started with the identification of its cause and correct diagnosis. Most often, cough in children is due to the increased viscosity of bronchial secretions, i.e. violation of sputum transport in the bronchial tree, and insufficient activity of ciliated epithelium. The main objective of the treatment of productive cough is dilution of sputum, bronchial secretion and excretion, thus necessitating the administration of mucolytics. Currently, one of the most famous mucolytics is acetylcysteine, cysteine amino acid product, such as ACC®. However, today the question of ACC® (acetylcysteine application in infants and young children is still debatable. This article presents a study whose objective was to evaluate the therapeutic efficacy and tolerability of ACC® (20 mg/ml solution in the treatment of bronchopulmonary diseases in children aged 2 to 6 years. Materials and methods. The study involved 60 children with acute tracheitis, simple bronchitis, acute obstructive bronchitis, recurrent bronchitis in the acute phase, community-acquired pneumonia, asthma exacerbation, cystic fibrosis. Patients of the main groups (n = 40 received ACC® (20 mg/ml solution at the age-specific dosage 3 times a day in combined treatment. Therapy of patients in the control group (n = 20 was conducted without ACC®. Results. During follow-up, patients who received ACC® had significant positive changes in the nature of cough, sputum viscosity and its amount as opposed to a comparison group of patients. Complete disappearance of cough was achieved on day 5–8 from the beginning of treatment, while in the control group patients, this time was longer. The evaluation of the effectiveness of the study drug showed that very good efficacy was achieved in 75 % of patients and good — in 20 %, and among patients who

Cryogenic high current discharges

International Nuclear Information System (INIS)

Meierovich, B.E.

1994-01-01

Z-pinches formed from frozen deuterium fibers by a rapidly rising current have enhanced stability and high neutron yield. The efforts to understand the enhanced stability and neutron yield on the basis of classical picture of Bennett equilibrium of the current channel has not given satisfactory results. The traditional approach does not take into account the essential difference between the frozen deuterium fiber Z-pinches and the usual Z-pinches such as exploding wires or classical gas-puffed Z-pinches. The very low temperature of the fiber atoms (10 K), together with the rapidly rising current, result in the coexistence of a high current channel with unionized fiber atoms for a substantial period of time. This phenomena lasts during the risetime. This approach takes into account the difference of the breakdown in a dielectric deuterium fiber and the breakdown in a metallic wire. This difference is essential to the understanding of specific features of cryogenic high current discharges. Z-pinches in frozen deuterium fibers should be considered as a qualitatively new phenomenon on the boundary of cryogenic and high current physics. It is a start of a new branch in plasma physics: the physics of cryogenic high current discharges

Current Approach to Child Rights

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Huseyin Dag

2015-03-01

Full Text Available Rights of children, legally or morally all over the world that children are born with; education, health, life, shelter; physical, psychological or sexual exploitation protection of such rights is universal concept used to describethemall. Rights of children is an issue that should be addressed in the concept of human rights. Today, there are many parts of the world that human rights violations, child-size and grew broader, more difficult to intervene in a way that is situated. The idea that children than in adults of different physical, physiological, behavioral and psychological characteristics that continuous growth and improve dawareness that the establishment of thecare of children a society where the problem is and scientific approach everyone with this responsibility should be installed is shaped in Geneva Declaration of Childrens Rights. Today, the international document related to childrens rights is the United Nations Convention on the Rights of the Child adoptedand approved by 193 countries. Child policy in Turkey where 25 million children live is an issue that should be seriously considered. Thus, childrens rights, children working in coordination with the contract on the basis of a policy should be implemented fully. [Cukurova Med J 2015; 40(1.000: 1-5

Current and future developments in nucleic acid-based diagnostics

International Nuclear Information System (INIS)

Viljoen, G.J.; Romito, M.; Kara, P.D.

2005-01-01

The detection and characterization of specific nucleic acids of medico-veterinary pathogens have proven invaluable for diagnostic purposes. Apart from hybridization and sequencing techniques, polymerase chain reaction (PCR) and numerous other methods have contributed significantly to this process. The integration of amplification and signal detection systems, including on-line real-time devices, have increased speed and sensitivity and greatly facilitated the quantification of target nucleic acids. They have also allowed for sequence characterization using melting or hybridization curves. Rugged portable real-time instruments for field use and robotic devices for processing samples are already available commercially. Various stem-loop DNA probes have been designed to have greater specificity for target recognition during real-time PCR. Various DNA fingerprinting techniques or post amplification sequencing are used to type pathogenic strains. Characterization according to DNA sequence is becoming more readily available as automated sequencers become more widely used. Reverse hybridization and to a greater degree DNA micro-arrays, are being used for genotyping related organisms and can allow for the detection of a large variety of different pathogens simultaneously. Non-radioactive labelling of DNA, especially using fluorophores and the principles of fluorescence resonance energy transfer, is now widely used, especially in real-time detection devices. Other detection methods include the use of surface plasmon resonance and MALDI-TOF mass spectrometry. In addition to these technological advances, contributions by bioinformatics and the description of unique signatures of DNA sequences from pathogens will contribute to the development of further assays for monitoring presence of pathogens. An important goal will be the development of robust devices capable of sensitively and specifically detecting a broad spectrum of pathogens that will be applicable for point

Diagnosis of hepatocellular carcinoma with gadoxetic acid-enhanced MRI: 2016 Consensus Recommendations of the Korean Society of Abdominal Radiology

International Nuclear Information System (INIS)

Park, Mi-Suk

2017-01-01

Diagnosis of hepatocellular carcinoma (HCC) with gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) poses certain unique challenges beyond the scope of current guidelines. The regional heterogeneity of HCC in demographic characteristics, prevalence, surveillance, and socioeconomic status necessitates different treatment approaches, leading to variations in survival outcomes. Considering the medical practices in Korea, the Korean Society of Abdominal Radiology (KSAR) study group for liver diseases has developed expert consensus recommendations for diagnosis of HCC by gadoxetic acid-enhanced MRI with updated perspectives, using a modified Delphi method. During the 39th Scientific Assembly and Annual Meeting of KSAR (2016), consensus was reached on 12 of 16 statements. These recommendations might serve to ensure a more standardized diagnosis of HCC by gadoxetic acid-enhanced MRI

Diagnosis of hepatocellular carcinoma with gadoxetic acid-enhanced MRI: 2016 Consensus Recommendations of the Korean Society of Abdominal Radiology

Energy Technology Data Exchange (ETDEWEB)

Park, Mi-Suk [Yonsei University College of Medicine, Severance Hospital, Seoul (Korea, Republic of)

2017-06-15

Diagnosis of hepatocellular carcinoma (HCC) with gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) poses certain unique challenges beyond the scope of current guidelines. The regional heterogeneity of HCC in demographic characteristics, prevalence, surveillance, and socioeconomic status necessitates different treatment approaches, leading to variations in survival outcomes. Considering the medical practices in Korea, the Korean Society of Abdominal Radiology (KSAR) study group for liver diseases has developed expert consensus recommendations for diagnosis of HCC by gadoxetic acid-enhanced MRI with updated perspectives, using a modified Delphi method. During the 39th Scientific Assembly and Annual Meeting of KSAR (2016), consensus was reached on 12 of 16 statements. These recommendations might serve to ensure a more standardized diagnosis of HCC by gadoxetic acid-enhanced MRI.

Animal model of acid-reflux esophagitis: pathogenic roles of acid/pepsin, prostaglandins, and amino acids.

Science.gov (United States)

Takeuchi, Koji; Nagahama, Kenji

2014-01-01

Esophagitis was induced in rats within 3 h by ligating both the pylorus and transitional region between the forestomach and glandular portion under ether anesthesia. This esophageal injury was prevented by the administration of acid suppressants and antipepsin drug and aggravated by exogenous pepsin. Damage was also aggravated by pretreatment with indomethacin and the selective COX-1 but not COX-2 inhibitor, whereas PGE2 showed a biphasic effect depending on the dose; a protection at low doses, and an aggravation at high doses, with both being mediated by EP1 receptors. Various amino acids also affected this esophagitis in different ways; L-alanine and L-glutamine had a deleterious effect, while L-arginine and glycine were highly protective, both due to yet unidentified mechanisms. It is assumed that acid/pepsin plays a major pathogenic role in this model of esophagitis; PGs derived from COX-1 are involved in mucosal defense of the esophagus; and some amino acids are protective against esophagitis. These findings also suggest a novel therapeutic approach in the treatment of esophagitis, in addition to acid suppressant therapy. The model introduced may be useful to test the protective effects of drugs on esophagitis and investigate the mucosal defense mechanism in the esophagus.

Xenobiotic/medium chain fatty acid: CoA ligase - a critical review on its role in fatty acid metabolism and the detoxification of benzoic acid and aspirin.

Science.gov (United States)

van der Sluis, Rencia; Erasmus, Elardus

2016-10-01

Activation of fatty acids by the acyl-CoA synthetases (ACSs) is the vital first step in fatty acid metabolism. The enzymatic and physiological characterization of the human xenobiotic/medium chain fatty acid: CoA ligases (ACSMs) has been severely neglected even though xenobiotics, such as benzoate and salicylate, are detoxified through this pathway. This review will focus on the nomenclature and substrate specificity of the human ACSM ligases; the biochemical and enzymatic characterization of ACSM1 and ACSM2B; the high sequence homology of the ACSM2 genes (ACSM2A and ACSM2B) as well as what is currently known regarding disease association studies. Several discrepancies exist in the current literature that should be taken note of. For example, the single nucleotide polymorphisms (SNPs) reported to be associated with aspirin metabolism and multiple risk factors of metabolic syndrome are incorrect. Kinetic data on the substrate specificity of the human ACSM ligases are non-existent and currently no data exist on the influence of SNPs on the enzyme activity of these ligases. One of the biggest obstacles currently in the field is that glycine conjugation is continuously studied as a one-step process, which means that key regulatory factors of the two individual steps remain unknown.

Carboxylic acids in crystallization of macromolecules: learning from successful crystallization experiments.

Science.gov (United States)

Offermann, Lesa R; He, John Z; Mank, Nicholas J; Booth, William T; Chruszcz, Maksymilian

2014-03-01

The production of macromolecular crystals suitable for structural analysis is one of the most important and limiting steps in the structure determination process. Often, preliminary crystallization trials are performed using hundreds of empirically selected conditions. Carboxylic acids and/or their salts are one of the most popular components of these empirically derived crystallization conditions. Our findings indicate that almost 40 % of entries deposited to the Protein Data Bank (PDB) reporting crystallization conditions contain at least one carboxylic acid. In order to analyze the role of carboxylic acids in macromolecular crystallization, a large-scale analysis of the successful crystallization experiments reported to the PDB was performed. The PDB is currently the largest source of crystallization data, however it is not easily searchable. These complications are due to a combination of a free text format, which is used to capture information on the crystallization experiments, and the inconsistent naming of chemicals used in crystallization experiments. Despite these difficulties, our approach allows for the extraction of over 47,000 crystallization conditions from the PDB. Initially, the selected conditions were investigated to determine which carboxylic acids or their salts are most often present in crystallization solutions. From this group, selected sets of crystallization conditions were analyzed in detail, assessing parameters such as concentration, pH, and precipitant used. Our findings will lead to the design of new crystallization screens focused around carboxylic acids.

Folic acid levels in some food staples in Ireland are on the decline: implications for passive folic acid intakes?

Science.gov (United States)

Kelly, F; Gibney, E R; Boilson, A; Staines, A; Sweeney, M R

2016-06-01

Neural tube defects are largely preventable by the maternal periconceptual consumption of folic acid. The aim of this study was to examine the levels of synthetic folic acid in foods and the range of food stuffs with added folic acid available to consumers in Ireland at the current time. Three audits of fortified foods available in supermarkets in the Republic of Ireland were conducted. Researchers visited supermarkets and obtained folic acid levels from nutrition labels in 2004, 2008 and 2013/4. Levels were compared using MS Excel. The profile of foods fortified with folic acid in 2013/4 has changed since 2004. The percentage of foods fortified with folic acid has decreased as has the level of added folic acid in some food staples, such as fat/dairy spreads. Bread, milk and spreads no longer contain as much folic acid as previously (2004 and 2008). This may contribute to a decrease in folate intake and therefore may contribute to an increase in NTD rates. Research on current blood concentrations of folate status markers is now warranted. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Decentralized Load Sharing in a Low-Voltage Direct Current Microgrid With an Adaptive Droop Approach Based on a Superimposed Frequency

DEFF Research Database (Denmark)

Peyghami, Saeed; Mokhtari, Hossein; Blaabjerg, Frede

2017-01-01

Conventional droop methods for load sharing control in low-voltage direct current microgrids suffer from poor power sharing and voltage regulation, especially in the case when operating many dc sources with long feeders. Hence, the communication-based approaches are employed to improve the load s...

Overview of ATX-101 (Deoxycholic Acid Injection): A Nonsurgical Approach for Reduction of Submental Fat.

Science.gov (United States)

Dayan, Steven H; Humphrey, Shannon; Jones, Derek H; Lizzul, Paul F; Gross, Todd M; Stauffer, Karen; Beddingfield, Frederick C

2016-11-01

In 2015, ATX-101 (deoxycholic acid injection; Kybella in the United States and Belkyra in Canada; Kythera Biopharmaceuticals, Inc., Westlake Village, CA [an affiliate of Allergan plc, Dublin, Ireland]) was approved as a first-in-class injectable drug for improvement in the appearance of moderate to severe convexity or fullness associated with submental fat. ATX-101 has been evaluated in a clinical development program that included 18 Phase 1 to 3 studies supporting the current indication. Since 2007, the toxicity and safety profiles of ATX-101 have been characterized in numerous preclinical studies, its pharmacokinetics, pharmacodynamics, and optimal treatment paradigm have been defined in multiple Phase 1 and 2 studies, and its efficacy and clinical safety have been confirmed in 4 large Phase 3 trials (2 conducted in Europe and 2 in the United States and Canada [REFINE-1 and REFINE-2]). As subcutaneous injection of deoxycholic acid has been shown to cause adipocytolysis, the reduction in submental fat achieved after ATX-101 treatment is expected to be long lasting. This prediction is confirmed by data from long-term follow-up studies of up to 4 years after last treatment with ATX-101, which demonstrate that the treatment response is maintained over time in most subjects. ATX-101 offers a durable, minimally invasive alternative to liposuction and surgery for addressing submental fullness.

Geochemical processes in acidic water caused by the weathering of metal sulphides; Procesos geoquimicos en aguas acidas por meteorizacion de sulfuros

Energy Technology Data Exchange (ETDEWEB)

Asta Andres, M. P.; Acero Salazar, P.; Auque Sanz, L. F.; Gimeno Serrano, M. J.; Gomez Jimenez, J. B.

2011-07-01

Acid generated by the oxidative dissolution of metal sulphides is one of the main sources of pollution in runoff water, groundwater, soils and sediments throughout the world. These types of water are very acidic and contain high concentrations of sulphate and other potentially contaminating elements such Fe, As, Cd, Sb, Zn and Cu. The acidity generated by sulphide oxidation processes is mainly controlled by the type, quantity and distribution of the sulphide-rich rocks, by the physical characteristics of the rocks (since they determine the accessibility of aqueous solutions and gases to the sulphides), by the presence of microorganisms able to catalyze the main chemical reactions involved in the formation of acid drainage, and by the existence of minerals capable of neutralizing acidity. As a result, the generation of acidic water is a very complex problem, the study of which must be undertaken via a multidisciplinary approach, taking into account geological, geochemical, mineralogical and microbiological aspects among others. The aim of our work is to provide a general overview of these processes and other factors that influence the generation and evolution of these systems, together with information concerning current scientific knowledge about each of these approaches. Thus we hope to provide a basic background to the understanding and study of acid-water systems associated with the weathering of metal sulphides and the processes involved in the generation, migration, evolution and natural attenuation of acidic waters in these environments. (Author) 65 refs.

Towards the design of 3D multiscale instructive tissue engineering constructs: Current approaches and trends.

Science.gov (United States)

Oliveira, Sara M; Reis, Rui L; Mano, João F

2015-11-01

The design of 3D constructs with adequate properties to instruct and guide cells both in vitro and in vivo is one of the major focuses of tissue engineering. Successful tissue regeneration depends on the favorable crosstalk between the supporting structure, the cells and the host tissue so that a balanced matrix production and degradation are achieved. Herein, the major occurring events and players in normal and regenerative tissue are overviewed. These have been inspiring the selection or synthesis of instructive cues to include into the 3D constructs. We further highlight the importance of a multiscale perception of the range of features that can be included on the biomimetic structures. Lastly, we focus on the current and developing tissue-engineering approaches for the preparation of such 3D constructs: top-down, bottom-up and integrative. Bottom-up and integrative approaches present a higher potential for the design of tissue engineering devices with multiscale features and higher biochemical control than top-down strategies, and are the main focus of this review. Copyright © 2015 Elsevier Inc. All rights reserved.

Stereoselective synthesis of a-hydroxy-b-amino acids: the chiral pool approach

Directory of Open Access Journals (Sweden)

RADOMIR N. SAICIC

2004-11-01

Full Text Available A method for the stereoselective homologation of a-amino acids into syn-a-hydroxy-b-amino acids is described, based on the conversion of stereoisomeric cyanohydrins into trans-oxazolines. The synthetic potential of the method is illustrated in the enantioselective formal synthesis of Bestatin.

Nitrous Acid as an Oxidant in Acidic Media

Science.gov (United States)

1979-09-25

current work is the account of Ogsts and Sawski3 who studied the oxidation of benzyl ethers at 90C in acidic, aqueous dioxane. They found an increase in...and G. Tobin, Chem. Com., 180 (1978); (b) J. Hoggett , R. Moodie, and K. Schofield, Chem. Comm., 605 (1969). 15. (a) B. Challis and A. Lawson. J. Chem

Experimental approaches to the interaction of the prion protein with nucleic acids and glycosaminoglycans: Modulators of the pathogenic conversion.

Science.gov (United States)

Silva, Jerson L; Vieira, Tuane C R G; Gomes, Mariana P B; Rangel, Luciana P; Scapin, Sandra M N; Cordeiro, Yraima

2011-03-01

The concept that transmissible spongiform encephalopathies (TSEs) are caused only by proteins has changed the traditional paradigm that disease transmission is due solely to an agent that carries genetic information. The central hypothesis for prion diseases proposes that the conversion of a cellular prion protein (PrP(C)) into a misfolded, β-sheet-rich isoform (PrP(Sc)) accounts for the development of (TSE). There is substantial evidence that the infectious material consists chiefly of a protein, PrP(Sc), with no genomic coding material, unlike a virus particle, which has both. However, prions seem to have other partners that chaperone their activities in converting the PrP(C) into the disease-causing isoform. Nucleic acids (NAs) and glycosaminoglycans (GAGs) are the most probable accomplices of prion conversion. Here, we review the recent experimental approaches that have been employed to characterize the interaction of prion proteins with nucleic acids and glycosaminoglycans. A PrP recognizes many nucleic acids and GAGs with high affinities, and this seems to be related to a pathophysiological role for this interaction. A PrP binds nucleic acids and GAGs with structural selectivity, and some PrP:NA complexes can become proteinase K-resistant, undergoing amyloid oligomerization and conversion to a β-sheet-rich structure. These results are consistent with the hypothesis that endogenous polyanions (such as NAs and GAGs) may accelerate the rate of prion disease progression by acting as scaffolds or lattices that mediate the interaction between PrP(C) and PrP(Sc) molecules. In addition to a still-possible hypothesis that nucleic acids and GAGs, especially those from the host, may modulate the conversion, the recent structural characterization of the complexes has raised the possibility of developing new diagnostic and therapeutic strategies. Copyright © 2010 Elsevier Inc. All rights reserved.

Current treatment approaches in patients with ankylosing spondylitis

Directory of Open Access Journals (Sweden)

Bilal Elbey

2015-03-01

Full Text Available Ankylosing spondylitis (AS is a chronic, inflammatory, rheumatic disease that mainly affects sacroiliac joints and spine. AS predominantly occurs more often in males and typically begins in the second or third decade. The mainstay of therapy in AS are nonsteroidal anti-inflammatory drugs, which reduce inflammation and pain. Disease modifying antirheumatic drugs (DMARD did not have enough evidence to prove their effect in AS treatment. The use of DMARD may not sufficient to improve the treatment and symptoms. Currently, TNF-blockers such as, Golimumab Etanersept Adalimumab İnfliksimab have promising results in the treatment of AS. TNF-blockers improve the clinical signs and symptoms, and improve the patients’ physical function and quality of life. This manuscript is focused that Current pharmacological treatments in patients with ankylosing spondylitis.

Fatty acid composition of Swedish bakery products, with emphasis on trans-fatty acids.

Science.gov (United States)

Trattner, Sofia; Becker, Wulf; Wretling, Sören; Öhrvik, Veronica; Mattisson, Irene

2015-05-15

Trans-fatty acids (TFA) have been associated with increased risk of coronary heart disease, by affecting blood lipids and inflammation factors. Current nutrition recommendations emphasise a limitation of dietary TFA intake. The aim of this study was to investigate fatty acid composition in sweet bakery products, with emphasis on TFA, on the Swedish market and compare fatty acid composition over time. Products were sampled in 2001, 2006 and 2007 and analysed for fatty acid composition by using GC. Mean TFA levels were 0.7% in 2007 and 5.9% in 2001 of total fatty acids. In 1995-97, mean TFA level was 14.3%. In 2007, 3 of 41 products had TFA levels above 2% of total fatty acids. TFA content had decreased in this product category, while the proportion of saturated (SFA) and polyunsaturated (PUFA) fatty acids had increased, mostly through increased levels of 16:0 and 18:2 n-6, respectively. The total fat content remained largely unchanged. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Elucidating the role of ferrous ion cocatalyst in enhancing dilute acid pretreatment of lignocellulosic biomass

Directory of Open Access Journals (Sweden)

Wei Hui

2011-11-01

Full Text Available Abstract Background Recently developed iron cocatalyst enhancement of dilute acid pretreatment of biomass is a promising approach for enhancing sugar release from recalcitrant lignocellulosic biomass. However, very little is known about the underlying mechanisms of this enhancement. In the current study, our aim was to identify several essential factors that contribute to ferrous ion-enhanced efficiency during dilute acid pretreatment of biomass and to initiate the investigation of the mechanisms that result in this enhancement. Results During dilute acid and ferrous ion cocatalyst pretreatments, we observed concomitant increases in solubilized sugars in the hydrolysate and reducing sugars in the (insoluble biomass residues. We also observed enhancements in sugar release during subsequent enzymatic saccharification of iron cocatalyst-pretreated biomass. Fourier transform Raman spectroscopy showed that major peaks representing the C-O-C and C-H bonds in cellulose are significantly attenuated by iron cocatalyst pretreatment. Imaging using Prussian blue staining indicated that Fe2+ ions associate with both cellulose/xylan and lignin in untreated as well as dilute acid/Fe2+ ion-pretreated corn stover samples. Analyses by scanning electron microscopy and transmission electron microscopy revealed structural details of biomass after dilute acid/Fe2+ ion pretreatment, in which delamination and fibrillation of the cell wall were observed. Conclusions By using this multimodal approach, we have revealed that (1 acid-ferrous ion-assisted pretreatment increases solubilization and enzymatic digestion of both cellulose and xylan to monomers and (2 this pretreatment likely targets multiple chemistries in plant cell wall polymer networks, including those represented by the C-O-C and C-H bonds in cellulose.

Method to precipitate metals on zirconium articles without using current

International Nuclear Information System (INIS)

Donaghy, R.E.

1978-01-01

Tubes or other bodies made of zirconium or Zr alloys used for taking up nuclear fuels are coated without current with a metal film to improve the mechanical and corrosion properties. The article is activated in a solution of ammonium bifluoride and sulphuric acid where an electrical conducting fixed and loose layer are fermed. This loose film is removed chemically by reacting with fluoroboric acid or hydrofluorosilica acid by ultrasonic treatment or by stripping from organic material (cotton, polyester, nylon). The current-free plating with Cu and Ni is described. The article is washed with deionized water between the process steps and finally degassed at a temperature of 150-200 0 C. (IHOE) [de

Neuromodulation by Mg2+ and polyamines of excitatory amino acid currents in rodent neurones in culture.

Science.gov (United States)

Kumamoto, E

1996-12-01

Excitatory amino-acid currents in rodent central neurones are mediated by the activation of glutamate receptors. Ionotropic types of the receptors are divided into alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA), kainate and N-methyl-D-aspartate (NMDA) receptors, and the former two are collectively called non-NMDA receptors. The NMDA receptor is modulated by a number of endogenous neuromodulators including Mg2+, polyamines, glycine and protons in extracellular solutions. Although it has been generally thought that each of the neuromodulators acts on a distinct site in the NMDA receptor, recent studies have revealed that these actions may be not necessarily independent of each other. The NMDA receptor response is not only inhibited but also potentiated by Mg2+, and the latter action is due to an interaction of a Mg2+ site with either glycine- or proton-binding site. In the presence of polyamines, a tonic inhibition by protons of the NMDA receptor response is relieved, resulting in a potentiation of the response. Alternatively, it has been recently revealed that there are some subtypes of non-NMDA receptors which are negatively modulated by polyamines in either extra- or intra cellular solutions. The difference in polyamine sensitivity among non-NMDA receptors is attributed to a distinction in their constituted subunits. The inhibition of non-NMDA receptor by intracellular polyamines results in inward rectification of the current-voltage relation which is not seen for polyamine-insensitive ones. This polyamine action is not mimicked by intracellular Mg2+.

New Approaches to Circulating Current Controllers for Modular Multilevel Converters

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Miguel Moranchel

2017-01-01

Full Text Available In the next years, modular multilevel converters (MMCs are going to be a next generation multilevel converters for medium to high voltage conversion applications, such as medium voltage motor drives, medium voltage flexible AC transmission systems (FACTS and high voltage direct current transmission. They provide advantages such as high modularity, availability, low generation of harmonics, etc. However, the circulating current distorts the leg currents and increases the rated current of power devices, which further increases system cost. This paper focuses on analysis and suppression of these currents in a MMC using two algorithms for tracking of harmonics. For this work resonant controllers and repetitive controllers have been selected. Both controllers are analyzed and simulations results are presented. Moreover, the controllers have been tested and validated for a three phase MMC operating as an inverter using a real processing platform based on Zynq by Xilinx and designed to control large multilevel converters and in a real MMC prototype. These results are provided to demonstrate the feasibility of the proposed method.

Toward Sustainable Amino Acid Production.

Science.gov (United States)

Usuda, Yoshihiro; Hara, Yoshihiko; Kojima, Hiroyuki

Because the global amino acid production industry has been growing steadily and is expected to grow even more in the future, efficient production by fermentation is of great importance from economic and sustainability viewpoints. Many systems biology technologies, such as genome breeding, omics analysis, metabolic flux analysis, and metabolic simulation, have been employed for the improvement of amino acid-producing strains of bacteria. Synthetic biological approaches have recently been applied to strain development. It is also important to use sustainable carbon sources, such as glycerol or pyrolytic sugars from cellulosic biomass, instead of conventional carbon sources, such as glucose or sucrose, which can be used as food. Furthermore, reduction of sub-raw substrates has been shown to lead to reduction of environmental burdens and cost. Recently, a new fermentation system for glutamate production under acidic pH was developed to decrease the amount of one sub-raw material, ammonium, for maintenance of culture pH. At the same time, the utilization of fermentation coproducts, such as cells, ammonium sulfate, and fermentation broth, is a useful approach to decrease waste. In this chapter, further perspectives for future amino acid fermentation from one-carbon compounds are described.

Optimization of Acid Black 172 decolorization by electrocoagulation using response surface methodology

Science.gov (United States)

2012-01-01

This paper utilizes a statistical approach, the response surface optimization methodology, to determine the optimum conditions for the Acid Black 172 dye removal efficiency from aqueous solution by electrocoagulation. The experimental parameters investigated were initial pH: 4–10; initial dye concentration: 0–600 mg/L; applied current: 0.5-3.5 A and reaction time: 3–15 min. These parameters were changed at five levels according to the central composite design to evaluate their effects on decolorization through analysis of variance. High R2 value of 94.48% shows a high correlation between the experimental and predicted values and expresses that the second-order regression model is acceptable for Acid Black 172 dye removal efficiency. It was also found that some interactions and squares influenced the electrocoagulation performance as well as the selected parameters. Optimum dye removal efficiency of 90.4% was observed experimentally at initial pH of 7, initial dye concentration of 300 mg/L, applied current of 2 A and reaction time of 9.16 min, which is close to model predicted (90%) result. PMID:23369574

Behaviour of lactic acid bacteria populations in Pecorino di Carmasciano cheese samples submitted to environmental conditions prevailing in the gastrointestinal tract: evaluation by means of a polyphasic approach.

Science.gov (United States)

Ricciardi, Annamaria; Blaiotta, Giuseppe; Di Cerbo, Alessandro; Succi, Mariantonietta; Aponte, Maria

2014-06-02

The survival of the autochthonous microflora, of samples collected during Pecorino di Carmasciano cheese manufacturing, was evaluated along the passage through a model mimicking the gastro-intestinal tract. The aim was the selection of lactic acid bacteria potentially able to arrive alive and metabolically active to the colon. The dynamics of lactic microbiota, throughout simulated digestion of cheese samples, were evaluated by means of an approach PCR-DGGE-based. Dominant species after cheese digestion could be related to the Lactobacillus plantarum and Lactobacillus casei groups. Sixty-three strains, which survived to simulated gastro-intestinal transit, were further evaluated for technological features and tolerance to human digestion in several experimental conditions, according to routinely used protocols. Bacterial survival appeared to be, more than strain-specific, strongly affected by experimental conditions, i.e. some strains showed an acceptable survival when resuspended in skim milk but not in ewe milk and vice versa. Nevertheless according to data, one gram of fresh Pecorino di Carmasciano cheese may convey to human colon about the same amount of viable LAB of a probiotic drink. Although it cannot be assumed that lactobacilli introduced with Pecorino have beneficial effects on the host, the healthy impact of autochthonous lactic acid bacteria of naturally fermented food has a broad consensus in the current literature. Copyright © 2014 Elsevier B.V. All rights reserved.

A human rights approach to advocacy for people with dementia: A review of current provision in England and Wales.

Science.gov (United States)

Dixon, Jeremy; Laing, Judy; Valentine, Christine

2018-01-01

In this article, we review current advocacy services for people with dementia in England and Wales (provided, respectively, under the Mental Capacity Act 2005 , the Mental Health Act 1983 /2007 and the Care Act 2014) through the lens of the United Nations Convention on the Rights of Persons with Disabilities (CRPD). We examine what a human rights' approach to advocacy support would entail, and whether current frameworks in England and Wales are adequate for this approach and provide a sufficient safeguard. First, we consider how the human rights of persons with dementia have become increasingly important and the extent to which the CRPD provides an opportunity to bolster safeguards and protection. Second, we discuss cause and case advocacy, and how these advocacy models could be shaped by the CRPD to promote the rights of persons with dementia at each stage of the disease. Third, we highlight current dilemmas and challenges in the provision of advocacy support in England and Wales by focusing on case law, commissioning of services and current practice. In particular, we analyse how the different legislative schemes have given rise to some confusion about the various advocacy provisions, as well as potential for overlap and discrepancies between different regimes. We also highlight the need for further research to address important gaps in knowledge, including the scale of need, patterns of referral and attitudes to advocacy services. The article concludes by highlighting how advocacy support could be recalibrated as a universal right to promote the aims and aspirations of the CRPD, and how education is needed to address the stigma of dementia and promote the benefits of advocacy in protecting the rights of those with dementia.

Approaches to improve the oral bioavailability and effects of novel anticancer drugs berberine and betulinic acid.

Directory of Open Access Journals (Sweden)

Chandraiah Godugu

Full Text Available The poor bioavailability of Berberine (BBR and Betulinic acid (BA limits the development of these promising anticancer agents for clinical use. In the current study, BBR and BA in spray dried (SD mucoadhesive microparticle formulations were prepared.A patented dual channel spray gun technology established in our laboratory was used for both formulations. Gastrointestinal (GI permeability studies were carried out using Caco-2 cell monolayer grown in in-vitro system. The oral bioavailability and pharmacokinetic profile of SD formulations were studied in Sprague Dawley rats. A549 orthotopic and H1650 metastatic NSCLC models were utilized for the anticancer evaluations.Pharmacokinetic studies demonstrated that BBR and BA SD formulations resulted in 3.46 and 3.90 fold respectively, significant increase in plasma Cmax concentrations. AUC levels were increased by 6.98 and 7.41 fold in BBR and BA SD formulations, respectively. Compared to untreated controls groups, 49.8 & 53.4% decrease in the tumor volumes was observed in SD formulation groups of BBR and BA, respectively. Molecular studies done on excised tumor (A549 tissue suggested that BBR in SD form resulted in a significant decrease in the survivin, Bcl-2, cyclin D1, MMP-9, HIF-1α, VEGF and CD31 expressions. Cleaved caspase 3, p53 and TUNEL expressions were increased in SD formulations. The RT-PCR analysis on H1650 tumor tissue suggested that p38, Phospho-JNK, Bax, BAD, cleaved caspase 3&8 mRNA expressions were significantly increased in BA SD formulations. Chronic administration of BBR and BA SD formulations did not show any toxicity.Due to significant increase in oral bioavailability and superior anticancer effects, our results suggest that spray drying is a superior alternative formulation approach for oral delivery of BBR and BA.

Development of acid soils tolerant wheat for Uasin Ngishu and Trans Zoia District of Kenya

International Nuclear Information System (INIS)

Karanja, L.; Kinyua, M.G.; Njau, P.N.

2001-01-01

The study used three methods to introduce and stabilise genetic variations in acid soil tolerant lines, which included hybridization, introduction and double haploid system. The results showed significant difference among the test lines with R973 line (average yield 0.94 tons/ ha) showing superiority over the other lines. A significant (p<0.05) test weight performance between the tested lines, with the highest test weight of 42.7 gm per 1000 kernel wt for R972, is reported. More work in the development of suitable varieties for acid soils tolerance, with the need for integrated approach with the agronomist, soil scientist, the breeder and pathologists working together is recommended. Characterisation and Marker Assisted Selection as a more suitable method to handle the current situation is suggested

Elastic Properties of Nucleic Acids by Single-Molecule Force Spectroscopy.

Science.gov (United States)

Camunas-Soler, Joan; Ribezzi-Crivellari, Marco; Ritort, Felix

2016-07-05

We review the current knowledge on the use of single-molecule force spectroscopy techniques to extrapolate the elastic properties of nucleic acids. We emphasize the lesser-known elastic properties of single-stranded DNA. We discuss the importance of accurately determining the elastic response in pulling experiments, and we review the simplest models used to rationalize the experimental data as well as the experimental approaches used to pull single-stranded DNA. Applications used to investigate DNA conformational transitions and secondary structure formation are also highlighted. Finally, we provide an overview of the effects of salt and temperature and briefly discuss the effects of contour length and sequence dependence.

Estimating infertility prevalence in low-to-middle-income countries: an application of a current duration approach to Demographic and Health Survey data

OpenAIRE

Polis, Chelsea B.; Cox, Carie M.; Tun?alp, ?zge; McLain, Alexander C.; Thoma, Marie E.

2017-01-01

Abstract STUDY QUESTION Can infertility prevalence be estimated using a current duration (CD) approach when applied to nationally representative Demographic and Health Survey (DHS) data collected routinely in low- or middle-income countries? SUMMARY ANSWER Our analysis suggests that a CD approach applied to DHS data from Nigeria provides infertility prevalence estimates comparable to other smaller studies in the same region. WHAT IS KNOWN ALREADY Despite associations with serious negative hea...

Direct Succinic Acid Production from Minimally Pretreated Biomass Using Sequential Solid-State and Slurry Fermentation with Mixed Fungal Cultures

Directory of Open Access Journals (Sweden)

Jerico Alcantara

2017-06-01

Full Text Available Conventional bio-based succinic acid production involves anaerobic bacterial fermentation of pure sugars. This study explored a new route for directly producing succinic acid from minimally-pretreated lignocellulosic biomass via a consolidated bioprocessing technology employing a mixed lignocellulolytic and acidogenic fungal co-culture. The process involved a solid-state pre-fermentation stage followed by a two-phase slurry fermentation stage. During the solid-state pre-fermentation stage, Aspergillus niger and Trichoderma reesei were co-cultured in a nitrogen-rich substrate (e.g., soybean hull to induce cellulolytic enzyme activity. The ligninolytic fungus Phanerochaete chrysosporium was grown separately on carbon-rich birch wood chips to induce ligninolytic enzymes, rendering the biomass more susceptible to cellulase attack. The solid-state pre-cultures were then combined in a slurry fermentation culture to achieve simultaneous enzymatic cellulolysis and succinic acid production. This approach generated succinic acid at maximum titers of 32.43 g/L after 72 h of batch slurry fermentation (~10 g/L production, and 61.12 g/L after 36 h of addition of fresh birch wood chips at the onset of the slurry fermentation stage (~26 g/L production. Based on this result, this approach is a promising alternative to current bacterial succinic acid production due to its minimal substrate pretreatment requirements, which could reduce production costs.

The current CEA/DRN safety approach for the design and the assessment of future nuclear installations

International Nuclear Information System (INIS)

Fiorini, G.L.; Pinto, P.L.; Costa, M.

1999-01-01

The purpose of the document is to present the basis of the safety approach currently implemented by the CEA/DRN, both for the design and the assessment of innovative systems and future nuclear installations. This approach is the result of the experience maturated, within the context of the CEA/DRN Innovative Programme through practical applications over several future concepts, both for fission and fusion reactors, as well as for waste disposal. The background of this experience is structured coherently with the European Safety Authorities recommendations and the European Utilities Requirements (EUR). The Defence In Depth principle and its application, by means, among others, of the barrier concept, remains the basis of the safety design process of future nuclear installations. Its adequacy is checked through the safety assessment. The methodology for Lines Of Defence (LOD) implementation as well as the one for the LOD architecture assessment is shown and motivated. The document shows that the clear and unambiguous definition of the safety approach provides an essential base for the organisation of the design tasks, being sure that the safety aspects are correctly taken into account and implemented, and for an adequate safety assessment of the final design, both from qualitative point of view as well as for the quantitative safety analysis. (author)

Omics analysis of acetic acid tolerance in Saccharomyces cerevisiae.

Science.gov (United States)

Geng, Peng; Zhang, Liang; Shi, Gui Yang

2017-05-01

Acetic acid is an inhibitor in industrial processes such as wine making and bioethanol production from cellulosic hydrolysate. It causes energy depletion, inhibition of metabolic enzyme activity, growth arrest and ethanol productivity losses in Saccharomyces cerevisiae. Therefore, understanding the mechanisms of the yeast responses to acetic acid stress is essential for improving acetic acid tolerance and ethanol production. Although 329 genes associated with acetic acid tolerance have been identified in the Saccharomyces genome and included in the database ( http://www.yeastgenome.org/observable/resistance_to_acetic_acid/overview ), the cellular mechanistic responses to acetic acid remain unclear in this organism. Post-genomic approaches such as transcriptomics, proteomics, metabolomics and chemogenomics are being applied to yeast and are providing insight into the mechanisms and interactions of genes, proteins and other components that together determine complex quantitative phenotypic traits such as acetic acid tolerance. This review focuses on these omics approaches in the response to acetic acid in S. cerevisiae. Additionally, several novel strains with improved acetic acid tolerance have been engineered by modifying key genes, and the application of these strains and recently acquired knowledge to industrial processes is also discussed.

New yeast-based approaches in production of palmitoleic acid

Czech Academy of Sciences Publication Activity Database

Kolouchová, I.; Sigler, Karel; Schreiberová, O.; Masák, J.; Řezanka, Tomáš

2015-01-01

Roč. 192, SEP 2015 (2015), s. 726-734 ISSN 0960-8524 R&D Projects: GA ČR(CZ) GAP503/11/0215; GA ČR GA14-00227S Institutional support: RVO:61388971 Keywords : Oleaginous yeasts * Non-oleaginous yeasts * Palmitoleic acid Subject RIV: EE - Microbiology, Virology Impact factor: 4.917, year: 2015

Safety analysis - current and future regulatory challenges

Energy Technology Data Exchange (ETDEWEB)

Jamieson, T., E-mail: Terry.Jamieson@cnsc-ccsn.gc.ca [Canadian Nuclear Safety Commission, Ottawa, ON (Canada)

2015-07-01

'Full text:' The current and future regulatory challenges associated with deterministic safety analysis are reviewed, including: 1. The CNSC's and safety control areas. 2. Traditional safety analysis approach. 3. Experience gained and impact. 4. Current analysis and regulatory approaches. 5. Current status. 6. Complexity and challenges In particular, the technical, regulatory and strategic aspects of these challenges are discussed. (author)

Safety analysis - current and future regulatory challenges

International Nuclear Information System (INIS)

Jamieson, T.

2015-01-01

'Full text:' The current and future regulatory challenges associated with deterministic safety analysis are reviewed, including: 1. The CNSC's and safety control areas. 2. Traditional safety analysis approach. 3. Experience gained and impact. 4. Current analysis and regulatory approaches. 5. Current status. 6. Complexity and challenges In particular, the technical, regulatory and strategic aspects of these challenges are discussed. (author)

Evaluation of different approaches to quantify strong organic acidity and acid-base buffering of organic-rich surface waters in Sweden.

Science.gov (United States)

Köhler, Stephan; Hruska, Jakub; Jönsson, Jörgen; Lövgren, Lars; Lofts, Stephen

2002-11-01

The role of organic acids in buffering pH in surface waters has been studied using a small brownwater stream (26mg L(-1) TOC) draining a forested catchment in Northern Sweden. Under the conditions of elevated pressure of CO2 stream field pH was changed between 3.5 and 6.1 during the acidification and alkalinization experiment. Acid-base characteristics of the natural organic matter were also determined using a high precision potentiometric method for a concentrated sample from the same stream. We compared the predictions from the Windermere Humic Aqueous Model (WHAM Model V), a model derived from the potentiometric titration (diprotic/monoprotic acid model) and a previously derived triprotic acid model which only uses alkalinity and TOC as input variables. The predicted buffering characteristics of all three models are very similar in the pH range 4.5-7 which suggests that during routine analysis alkalinity and TOC are sufficient to give a good estimate of organic acid anion charge contribution in a large range of surface waters. A slightly adjusted version of WHAM V successfully describes the organic charge contribution in a large number of sampled surface water lakes, which were previously used to calibrate the triprotic model.

An effective assessment of valproate sodium-induced hepatotoxicity with UPLC-MS and (1)HNMR-based metabonomics approach.

Science.gov (United States)

Huo, Taoguang; Chen, Xi; Lu, Xiumei; Qu, Lianyue; Liu, Yang; Cai, Shuang

2014-10-15

Valproate sodium is one of the most prescribed antiepileptic drugs. However, valproate sodium has various side effects, especially its toxicity on liver. Current markers for toxicity reflect mostly the late stages of tissue damage; thus, more efficient methods for toxicity evaluation are desired. To evaluate the toxicity of valproate sodium on liver, we performed both UPLC-MS and (1)HNMR-based metabonomics analysis of serum samples from 34 epileptic patients (age: 42.0±18.6, 18 male/16 female) after valproate sodium treatment. Compared to conventional markers, the serum metabolic profiles provided clear distinction of the valproate sodium induced normal liver function and abnormal liver function in epileptic patients. Through multivariate statistical analysis, we identified marker metabolites associated with the hepatotoxicity induced by valproate sodium, such as glucose, lactate, acetoacetate, VLDL/LDL, lysophosphatidylcholines, phosphatidylcholines, choline, creatine, amino acids, N-acetyl glycoprotein, pyruvate and uric acid. This metabonomics approach may provide effective way to evaluate the valproate sodium-induced toxicity in a manner that can complement current measures. This approach is expected to find broader application in other drug-induced toxicity assessment. Copyright © 2014 Elsevier B.V. All rights reserved.

Novel Biochip Platform for Nucleic Acid Analysis

Directory of Open Access Journals (Sweden)

Juan J. Diaz-Mochon

2012-06-01

Full Text Available This manuscript describes the use of a novel biochip platform for the rapid analysis/identification of nucleic acids, including DNA and microRNAs, with very high specificity. This approach combines a unique dynamic chemistry approach for nucleic acid testing and analysis developed by DestiNA Genomics with the STMicroelectronics In-Check platform, which comprises two microfluidic optimized and independent PCR reaction chambers, and a sequential microarray area for nucleic acid capture and identification by fluorescence. With its compact bench-top “footprint” requiring only a single technician to operate, the biochip system promises to transform and expand routine clinical diagnostic testing and screening for genetic diseases, cancers, drug toxicology and heart disease, as well as employment in the emerging companion diagnostics market.

Current approach to diagnosis and management of osteoarthritis ...

African Journals Online (AJOL)

There is extreme variability in presentation at different joint sites and between individuals. Management of OA involves a comprehensive approach consisting of preventative measures and numerous therapeutic modalities which should be tailored to individual needs. The family practitioner plays a vital role in the diagnosis ...

The first proton sponge-based amino acids: synthesis, acid-base properties and some reactivity.

Science.gov (United States)

Ozeryanskii, Valery A; Gorbacheva, Anastasia Yu; Pozharskii, Alexander F; Vlasenko, Marina P; Tereznikov, Alexander Yu; Chernov'yants, Margarita S

2015-08-21

The first hybrid base constructed from 1,8-bis(dimethylamino)naphthalene (proton sponge or DMAN) and glycine, N-methyl-N-(8-dimethylamino-1-naphthyl)aminoacetic acid, was synthesised in high yield and its hydrobromide was structurally characterised and used to determine the acid-base properties via potentiometric titration. It was found that the basic strength of the DMAN-glycine base (pKa = 11.57, H2O) is on the level of amidine amino acids like arginine and creatine and its structure, zwitterionic vs. neutral, based on the spectroscopic (IR, NMR, mass) and theoretical (DFT) approaches has a strong preference to the zwitterionic form. Unlike glycine, the DMAN-glycine zwitterion is N-chiral and is hydrolytically cleaved with the loss of glycolic acid on heating in DMSO. This reaction together with the mild decarboxylative conversion of proton sponge-based amino acids into 2,3-dihydroperimidinium salts under air-oxygen was monitored with the help of the DMAN-alanine amino acid. The newly devised amino acids are unique as they combine fluorescence, strongly basic and redox-active properties.

An Approach to Model Earth Conductivity Structures with Lateral Changes for Calculating Induced Currents and Geoelectric Fields during Geomagnetic Disturbances

Directory of Open Access Journals (Sweden)

Bo Dong

2015-01-01

Full Text Available During geomagnetic disturbances, the telluric currents which are driven by the induced electric fields will flow in conductive Earth. An approach to model the Earth conductivity structures with lateral conductivity changes for calculating geoelectric fields is presented in this paper. Numerical results, which are obtained by the Finite Element Method (FEM with a planar grid in two-dimensional modelling and a solid grid in three-dimensional modelling, are compared, and the flow of induced telluric currents in different conductivity regions is demonstrated. Then a three-dimensional conductivity structure is modelled and the induced currents in different depths and the geoelectric field at the Earth’s surface are shown. The geovoltages by integrating the geoelectric field along specific paths can be obtained, which are very important regarding calculations of geomagnetically induced currents (GIC in ground-based technical networks, such as power systems.

Recovering uranium from phosphoric acid

International Nuclear Information System (INIS)

Anon.

1979-01-01

Wet-process phosphoric acid contains a significant amount of uranium. This uranium totals more than 1,500 tons/yr in current U.S. acid output--and projections put the uranium level at 8,000 tons/yr in the year 2000. Since the phosphoric acid is a major raw material for fertilizers, uranium finds its way into those products and is effectively lost as a resource, while adding to the amount of radioactive material that can contaminate the food chain. So, resource-conservation and environmental considerations both make recovery of the uranium from phosphoric acid desirable. This paper describes the newly developed process for recovering uranium from phosphoric acid by using solvent-extraction technique. After many extractants had been tested, the researchers eventually selected the combination of di (2-ethylhexyl) phosphoric acid (DEPA) and trioctylphosphine oxide (TOPO) as the most suitable. The flowscheme of the process is included

Glycolic Acid Physical Properties, Impurities, And Radiation Effects Assessment

International Nuclear Information System (INIS)

Pickenheim, B.; Bibler, N.

2010-01-01

The DWPF is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H 2 and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O 2 when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and pumping of the solution may be hindered. A

A Novel Approach in Cinnamic Acid Synthesis: Direct Synthesis of Cinnamic Acids from Aromatic Aldehydes and Aliphatic Carboxylic Acids in the Presence of Boron Tribromide

Directory of Open Access Journals (Sweden)

M. Onciu

2005-02-01

Full Text Available Cinnamic acids have been prepared in moderate to high yields by a new direct synthesis using aromatic aldehydes and aliphatic carboxylic acids, in the presence of boron tribromide as reagent, 4-dimethylaminopyridine (4-DMAP and pyridine (Py as bases and N-methyl-2-pyrolidinone (NMP as solvent, at reflux (180-190°C for 8-12 hours.

Modular Regiospecific Synthesis of Nitrated Fatty Acids

DEFF Research Database (Denmark)

Hock, Katharina J.; Grimmer, Jennifer; Göbel, Dominik

2016-01-01

Endogenous nitrated fatty acids are an important class of signaling molecules. Herein a modular route for the efficient and regiospecific preparation of nitrooleic acids as well as various analogues is described. The approach is based on a simple set of alkyl halides as common building blocks...

One-Tube-Only Standardized Site-Directed Mutagenesis: An Alternative Approach to Generate Amino Acid Substitution Collections.

Directory of Open Access Journals (Sweden)

Janire Mingo

Full Text Available Site-directed mutagenesis (SDM is a powerful tool to create defined collections of protein variants for experimental and clinical purposes, but effectiveness is compromised when a large number of mutations is required. We present here a one-tube-only standardized SDM approach that generates comprehensive collections of amino acid substitution variants, including scanning- and single site-multiple mutations. The approach combines unified mutagenic primer design with the mixing of multiple distinct primer pairs and/or plasmid templates to increase the yield of a single inverse-PCR mutagenesis reaction. Also, a user-friendly program for automatic design of standardized primers for Ala-scanning mutagenesis is made available. Experimental results were compared with a modeling approach together with stochastic simulation data. For single site-multiple mutagenesis purposes and for simultaneous mutagenesis in different plasmid backgrounds, combination of primer sets and/or plasmid templates in a single reaction tube yielded the distinct mutations in a stochastic fashion. For scanning mutagenesis, we found that a combination of overlapping primer sets in a single PCR reaction allowed the yield of different individual mutations, although this yield did not necessarily follow a stochastic trend. Double mutants were generated when the overlap of primer pairs was below 60%. Our results illustrate that one-tube-only SDM effectively reduces the number of reactions required in large-scale mutagenesis strategies, facilitating the generation of comprehensive collections of protein variants suitable for functional analysis.

Uric acid in major depressive and anxiety disorders.

Science.gov (United States)

Black, Catherine N; Bot, Mariska; Scheffer, Peter G; Snieder, Harold; Penninx, Brenda W J H

2018-01-01

Uric acid has neuroprotective effects, owing to its antioxidant properties. Lowered antioxidant capacity, causing increased oxidative stress, may be involved in affective disorders and might be altered by antidepressants. This study investigated the association of plasma uric acid, the greatest contributor to blood antioxidant capacity, with major depressive disorder (MDD) and anxiety disorders. Data were from the Netherlands Study of Depression and Anxiety including patients with current (N = 1648), remitted (N = 609) MDD and/or anxiety disorders (of which N = 710 antidepressant users) and 618 controls. Diagnoses were established with the Composite International Diagnostic Interview. Symptom severity was assessed with the Inventory of Depressive Symptoms-Self Report, Beck Anxiety Inventory and Fear Questionnaire. Uric acid was measured in plasma. Analyses were adjusted for sociodemographic, health and lifestyle variables. Plasma uric acid adjusted mean levels were lower in current MDD and/or anxiety disorder(s) (289μmol/l) compared to remitted disorders (298μmol/l, p uric acid. Limitations include the lack of data on dietary intake which could be a potential confounding factor. From these cross-sectional findings, the association between uric acid and psychopathology cannot be inferred to be causal. This large scale study finds plasma uric acid levels are lower in current, but not remitted, MDD and/or anxiety disorders, according to a dose-response gradient. This suggests the involvement of decreased antioxidant status in affective disorders, and points to their potential as an avenue for treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Anodal transcranial direct current stimulation over right dorsolateral prefrontal cortex alters decision making during approach-avoidance conflict.

Science.gov (United States)

Chrysikou, Evangelia G; Gorey, Claire; Aupperle, Robin L

2017-03-01

Approach-avoidance conflict (AAC) refers to situations associated with both rewarding and threatening outcomes. The AAC task was developed to measure AAC decision-making. Approach behavior during this task has been linked to self-reported anxiety sensitivity and has elicited anterior cingulate, insula, caudate and right dorsolateral prefrontal cortex (dlPFC) activity, with right lateral PFC tracking the extent of approach behavior. Guided by these results, we used excitatory transcranial direct current stimulation (tDCS) to demonstrate the causal involvement of right dlPFC in AAC decision-making. Participants received anodal tDCS at 1.5mA over either left or right dlPFC or sham stimulation, while performing the AAC task and a control short-term memory task. Analyses of variance (ANOVA) revealed that for individuals with high anxiety sensitivity excitatory right (but not left or sham) dlPFC stimulation elicited measurable decreases in approach behavior during conflict. Excitatory left (but not right or sham) dlPFC simulation improved performance on the control task. These results support a possible asymmetry between the contributions of right and left dlPFC to AAC resolution during emotional decision-making. Increased activity in right dlPFC may contribute to anxiety-related symptoms and, as such, serve as a neurobehavioral target of anxiolytic treatments aiming to decrease avoidance behavior. © The Author (2016). Published by Oxford University Press.

The current status of exposure-driven approaches for chemical safety assessment: A cross-sector perspective.

Science.gov (United States)

Sewell, Fiona; Aggarwal, Manoj; Bachler, Gerald; Broadmeadow, Alan; Gellatly, Nichola; Moore, Emma; Robinson, Sally; Rooseboom, Martijn; Stevens, Alexander; Terry, Claire; Burden, Natalie

2017-08-15

For the purposes of chemical safety assessment, the value of using non-animal (in silico and in vitro) approaches and generating mechanistic information on toxic effects is being increasingly recognised. For sectors where in vivo toxicity tests continue to be a regulatory requirement, there has been a parallel focus on how to refine studies (i.e. reduce suffering and improve animal welfare) and increase the value that in vivo data adds to the safety assessment process, as well as where to reduce animal numbers where possible. A key element necessary to ensure the transition towards successfully utilising both non-animal and refined safety testing is the better understanding of chemical exposure. This includes approaches such as measuring chemical concentrations within cell-based assays and during in vivo studies, understanding how predicted human exposures relate to levels tested, and using existing information on human exposures to aid in toxicity study design. Such approaches promise to increase the human relevance of safety assessment, and shift the focus from hazard-driven to risk-driven strategies similar to those used in the pharmaceutical sectors. Human exposure-based safety assessment offers scientific and 3Rs benefits across all sectors marketing chemical or medicinal products. The UK's National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) convened an expert working group of scientists across the agrochemical, industrial chemical and pharmaceutical industries plus a contract research organisation (CRO) to discuss the current status of the utilisation of exposure-driven approaches, and the challenges and potential next steps for wider uptake and acceptance. This paper summarises these discussions, highlights the challenges - particularly those identified by industry - and proposes initial steps for moving the field forward. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Hyaluronic Acid Assays

DEFF Research Database (Denmark)

Itenov, Theis S; Kirkby, Nikolai S; Bestle, Morten H

2015-01-01

BACKGROUD: Hyaluronic acid (HA) is proposed as a marker of functional liver capacity. The aim of the present study was to compare a new turbidimetric assay for measuring HA with the current standard method. METHODS: HA was measured by a particle-enhanced turbidimetric immunoassay (PETIA) and enzyme...

Intensification of conversion of glucose to lactic acid : equilibria and kinetics for back extraction of lactic acid using trimethylamine

NARCIS (Netherlands)

Wasewar, Kailas L.; Heesink, A. Bert M.; Versteeg, Geert F.; Pangarkar, Vishwas G.

2004-01-01

Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

Intensification of conversion of glucose to lactic acid: equilibria and kinetics for back extraction of lactic acid using trimethylamine

NARCIS (Netherlands)

Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

2004-01-01

Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

Genome-scale model-driven strain design for dicarboxylic acid production in Yarrowia lipolytica.

Science.gov (United States)

Mishra, Pranjul; Lee, Na-Rae; Lakshmanan, Meiyappan; Kim, Minsuk; Kim, Byung-Gee; Lee, Dong-Yup

2018-03-19

Recently, there have been several attempts to produce long-chain dicarboxylic acids (DCAs) in various microbial hosts. Of these, Yarrowia lipolytica has great potential due to its oleaginous characteristics and unique ability to utilize hydrophobic substrates. However, Y. lipolytica should be further engineered to make it more competitive: the current approaches are mostly intuitive and cumbersome, thus limiting its industrial application. In this study, we proposed model-guided metabolic engineering strategies for enhanced production of DCAs in Y. lipolytica. At the outset, we reconstructed genome-scale metabolic model (GSMM) of Y. lipolytica (iYLI647) by substantially expanding the previous models. Subsequently, the model was validated using three sets of published culture experiment data. It was finally exploited to identify genetic engineering targets for overexpression, knockout, and cofactor modification by applying several in silico strain design methods, which potentially give rise to high yield production of the industrially relevant long-chain DCAs, e.g., dodecanedioic acid (DDDA). The resultant targets include (1) malate dehydrogenase and malic enzyme genes and (2) glutamate dehydrogenase gene, in silico overexpression of which generated additional NADPH required for fatty acid synthesis, leading to the increased DDDA fluxes by 48% and 22% higher, respectively, compared to wild-type. We further investigated the effect of supplying branched-chain amino acids on the acetyl-CoA turn-over rate which is key metabolite for fatty acid synthesis, suggesting their significance for production of DDDA in Y. lipolytica. In silico model-based strain design strategies allowed us to identify several metabolic engineering targets for overproducing DCAs in lipid accumulating yeast, Y. lipolytica. Thus, the current study can provide a methodological framework that is applicable to other oleaginous yeasts for value-added biochemical production.

Rotor Current Control of DFIG for Improving Fault Ride - Through Using a Novel Sliding Mode Control Approach

Science.gov (United States)

Cai, Guowei; Liu, Cheng; Yang, Deyou

2013-11-01

The doubly fed induction generators (DFIG) have been recognized as the dominant technology used in wind power generation systems with the rapid development of wind power. However, continuous operation of DFIG may cause a serious wind turbine generators tripping accident, due to destructive over-current in the rotor winding which is caused by the power system fault or inefficient fault ride-through (FRT) strategy. A new rotor current control scheme in the rotor-side converter (RSC) ispresented to enhance FRT capacities of grid-connected DFIG. Due to the strongly nonlinear nature of DFIG and insensitive to DFIG parameter's variations, a novel sliding mode controller was designed. The controller combines extended state observer (ESO) with sliding model variable structure control theory. The simulation is carried out to verify the effectiveness of the proposed control approach under various types of grid disturbances. It is shown that the proposed controller provides enhanced transient features than the classic proportional-integral control. The proposed control method can effectively reduce over-current in the RSC, and the transient pulse value of electromagnetic torque is too large under power grid fault.

Assessing the Impact of Current National Policies to Reduce Salt ...

International Development Research Centre (IDRC) Digital Library (Canada)

Assessing the Impact of Current National Policies to Reduce Salt and Trans Fatty Acids in Argentina ... The Codex Alimentarius, or international food safety standards, will also decrease trans fatty acids (TFA) ... Researchers will develop a strategy to share results with policymakers and other stakeholders. ... Journal articles.

Current Approaches and New Developments in the Pharmacological Management of Tourette Syndrome.

Science.gov (United States)

Quezada, Julio; Coffman, Keith A

2018-01-01

Tourette syndrome (TS) is a neurodevelopmental disorder of unknown etiology characterized by spontaneous, involuntary movements and vocalizations called tics. Once thought to be rare, TS affects 0.3-1% of the population. Tics can cause physical discomfort, emotional distress, social difficulties, and can interfere with education and desired activities. The pharmacologic treatment of TS is particularly challenging, as currently the genetics, neurophysiology, and neuropathology of this disorder are still largely unknown. However, clinical experience gained from treating TS has helped us better understand its pathogenesis and, as a result, derive treatment options. The strongest data exist for the antipsychotic agents, both typical and atypical, although their use is often limited in children and adolescents due to their side-effect profiles. There are agents in a variety of other pharmacologic categories that have evidence for the treatment of TS and whose side-effect profiles are more tolerable than the antipsychotics; these include clonidine, guanfacine, baclofen, topiramate, botulinum toxin A, tetrabenazine, and deutetrabenazine. A number of new agents are being developed and tested as potential treatments for TS. These include valbenazine, delta-9-tetrahydrocannabidiol, and ecopipam. Additionally, there are agents with insufficient data for efficacy, as well as agents that have been shown to be ineffective. Those without sufficient data for efficacy include clonazepam, ningdong granule, 5-ling granule, omega-3 fatty acids, and n-acetylcysteine. The agents that have been shown to be ineffective include pramipexole and metoclopramide. We will review all of the established pharmacologic treatments, and discuss those presently in development.

Review: Current trends in coral transplantation – an approach to preserve biodiversity

Directory of Open Access Journals (Sweden)

ABDELNABY ORABI

2013-04-01

Full Text Available Ammar MSA,El-Gammal F, Nassar M, Belal A, Farag W, El-Mesiry G, El-Haddad K, Orabi A, Abdelreheem A, Shaaban A. 2013. Review: Current trends in coral transplantation – an approach to preserve biodiversity. Biodiversitas 14: 43-53. The increasing rates of coral mortality associated with the rise in stress factors and the lack of adequate recovery worldwide have urged recent calls for actions by the scientific, conservation, and reef management communities. This work reviews the current trends in coral transplantation. Transplantation of coral colonies or fragments, whether from aqua-, mariculture or harvesting from a healthy colony, has been the most frequently recommended action for increasing coral abundance on damaged or degraded reefs and for conserving listed or “at-risk” species. Phytoplanktons are important for providing transplanted corals with complex organic compounds through photosynthesis. Artificial surfaces like concrete blocks, wrecks or other purpose-designed structures can be introduced for larval settlement. New surfaces can also be created through electrolysis. Molecular biological tools can be used to select sites for rehabilitation by asexual recruits. Surface chemistry and possible inputs of toxic leachate from artificial substrates are considered as important factors affecting natural recruitment. Transplants should be carefully maintained , revisited and reattached at least weekly in the first month and at least fortnightly in the next three months. Studies on survivorship and the reproductive ability of transplanted coral fragments are important for coral reef restoration. A coral nursery may be considered as a pool for local species that supplies reef-managers with unlimited coral colonies for sustainable management. Transplanting corals for making artificial reefs can be useful for increasing biodiversity, providing tourist diving, fishing and surfing; creating new artisanal and commercial fishing opportunities

Genomics of lactic acid bacteria: Current status and potential applications.

Science.gov (United States)

Wu, Chongde; Huang, Jun; Zhou, Rongqing

2017-08-01

Lactic acid bacteria (LAB) are widely used for the production of a variety of foods and feed raw materials where they contribute to flavor and texture of the fermented products. In addition, specific LAB strains are considered as probiotic due to their health-promoting effects in consumers. Recently, the genome sequencing of LAB is booming and the increased amount of published genomics data brings unprecedented opportunity for us to reveal the important traits of LAB. This review describes the recent progress on LAB genomics and special emphasis is placed on understanding the industry-related physiological features based on genomics analysis. Moreover, strategies to engineer metabolic capacity and stress tolerance of LAB with improved industrial performance are also discussed.

Biobased organic acids production by metabolically engineered microorganisms

DEFF Research Database (Denmark)

Chen, Yun; Nielsen, Jens

2016-01-01

Bio-based production of organic acids via microbial fermentation has been traditionally used in food industry. With the recent desire to develop more sustainable bioprocesses for production of fuels, chemicals and materials, the market for microbial production of organic acids has been further...... expanded as organic acids constitute a key group among top building block chemicals that can be produced from renewable resources. Here we review the current status for production of citric acid and lactic acid, and we highlight the use of modern metabolic engineering technologies to develop high...... performance microbes for production of succinic acid and 3-hydroxypropionic acid. Also, the key limitations and challenges in microbial organic acids production are discussed...

Approach to acid-base disorders – a clinical chemistry perspective

African Journals Online (AJOL)

Table 1. Simple acid-base disorders. Disorder. pH. pCO2. HCO3. -. Clinical examples. Respiratory acidosis ... Lactic acidosis or diabetic ketoacidosis and vomiting. Triple disorder: .... Renal tubular acidosis type 1 and 2. Ureteral diversion to ...

Modulated Current Drive Measurements

International Nuclear Information System (INIS)

Petty, C.C.; Lohr, J.; Luce, T.C.; Prater, R.; Cox, W.A.; Forest, C.B.; Jayakumar, R.J.; Makowski, M.A.

2005-01-01

A new measurement approach is presented which directly determines the noninductive current profile from the periodic response of the motional Stark effect (MSE) signals to the slow modulation of the external current drive source. A Fourier transform of the poloidal magnetic flux diffusion equation is used to analyze the MSE data. An example of this measurement technique is shown using modulated electron cyclotron current drive (ECCD) discharges from the DIII-D tokamak

Economic evaluations of pharmacogenetic approaches in infectious diseases: a review of current approaches and evaluation of critical aspects affecting their quality

Directory of Open Access Journals (Sweden)

Paolo Meoni

2013-11-01

Full Text Available Pharmacogenetics holds great potential for improving the effectiveness of treatment modalities in infectious diseases by taking into account the genetic determinants of both the host and infectious agents’ individuality. Better utilization of resources and improved therapeutic efficiency are the expected outcomes of personalized medicine using pharmacogenetic and pharmacogenomics information made available by technological advances. However, there has been growing concern in the clinical community regarding the evaluation of the true benefits of these approaches. This perception is partly due to the limited number and perceived poor quality of economic evaluations in this field, and initiatives aimed at harmonizing and communicating strategies improving the quality of these studies and their acceptance by the clinical community are greatly needed. This paper reviews current literature of economic evaluations of pharmacogenetics interventions guiding pharmacotherapy in infectious diseases. PubMed and the NHS Centre for Reviews and Dissemination databases were searched using a combination of five broad research terms related to pharmacogenetic approaches, and papers relative to economic evaluations of pharmacogenetic interventions in infectious diseases retained for further analysis. Using these criteria, a total of 14 papers were included in this review. The area of economic evaluation of pharmacogenetic interventions in infectious diseases remains understudied and would benefit from greater harmonization. The main weaknesses of evaluations reviewed in this paper seem to be represented by poor evidence of pharmacogenetic marker validation, inconsistencies in the selection of costs and utility included in the economic models and the choice of sensitivity analysis. All these factors limit the overall transparency of the studies, greater acceptance of their results and applicability to diverse and possibly resourcelimited environments where these

The simple solutions concept: a useful approach to estimate deviation from ideality in solvent extraction

International Nuclear Information System (INIS)

Sorel, C.; Pacary, V.

2010-01-01

The solvent extraction systems devoted to uranium purification from crude ore to spent fuel involve concentrated solutions in which deviation from ideality can not be neglected. The Simple Solution Concept based on the behaviour of isopiestic solutions has been applied to quantify the activity coefficients of metals and acids in the aqueous phase in equilibrium with the organic phase. This approach has been validated on various solvent extraction systems such as trialkylphosphates, malonamides or acidic extracting agents both on batch experiments and counter-current tests. Moreover, this concept has been successfully used to estimate the aqueous density which is useful to quantify the variation of volume and to assess critical parameters such as the number density of nuclides. (author)

Amino acid chirality breaking by N-phosphorylation

International Nuclear Information System (INIS)

Zhao Yufen; Yan Qingjin.

1995-01-01

The chirality breaking of amino acid is a focus issue in the origin of life. For chemists, there are some interesting chemical approaches to solve the symmetry breaking problem. Our previous experiments indicated that when amino acids were phosphorylated, there were many bio-mimic reactions happened. In this paper, it was found that there had significant difference between the N-phosphoryl L- and D- amino acids such as serine and threonine. The optical rotation tracing experiments of the racemic N-phosphoamino acids also showed the similar results. The chirality breaking of amino acids by N-phosphorylation was a novel phenomena. (author). 3 refs, 1 fig. Abstract only

Optimization of an innovative approach involving mechanical activation and acid digestion for the extraction of lithium from lepidolite

Science.gov (United States)

Vieceli, Nathália; Nogueira, Carlos A.; Pereira, Manuel F. C.; Durão, Fernando O.; Guimarães, Carlos; Margarido, Fernanda

2018-01-01

The recovery of lithium from hard rock minerals has received increased attention given the high demand for this element. Therefore, this study optimized an innovative process, which does not require a high-temperature calcination step, for lithium extraction from lepidolite. Mechanical activation and acid digestion were suggested as crucial process parameters, and experimental design and response-surface methodology were applied to model and optimize the proposed lithium extraction process. The promoting effect of amorphization and the formation of lithium sulfate hydrate on lithium extraction yield were assessed. Several factor combinations led to extraction yields that exceeded 90%, indicating that the proposed process is an effective approach for lithium recovery.

Strategies for controlling acid rain: economic considerations

International Nuclear Information System (INIS)

Forster, B.A.; Crocker, T.D.

1992-01-01

There are two competing approaches to reducing pollution such as the acid rain precursors SOsub(2) and NOsub(x). In the command and control approach, pollution control legislation may dictate the technological method by which specified pollution reductions are to be achieved. A key feature of command-and-control regulations is their inflexibility. The alternative approach relies on market mechanisms and incentives to induce firms to reduce pollution voluntarily. Economists generally prefer this approach because it permits flexibility for firms in selecting abatement methods to minimize costs. This chapter deals with qualitative issues in determining and achieving an ''optimal'' pollution level using various taxes, subsidies or quantitative restrictions. Alternative permit schemes for achieving regional pollution control are considered. Statistical studies are discussed which compare the command-and-control approach with the economic incentives approach and show that there are substantial cost differences between them in most cases. Finally, some institutional factors, that may lead to more costly acid rain control schemes being selected, are examined. A list of 61 references is appended. (UK)

Are there missing convective currents?

International Nuclear Information System (INIS)

Chen, C.Y.

1992-01-01

It is revealed in this letter that as far as distribution functions obtained from gyrokinetic equations are concerned, the standard formulae to evaluate currents in plasmas are not applicable due to the fact that those distribution functions are given in a moving coordinate frame and the moving is essentially related to perturbed fields. With heuristic and analytic approaches, appropriate formulae are obtained to evaluate several types of currents in plasmas of which some have been missing in previous approaches. (author). 6 refs, 1 fig

Mite Pests in Plant Crops – Current Issues, Inovative Approaches and Possibilities for Controlling Them (2

Directory of Open Access Journals (Sweden)

Radmila Petanović

2010-01-01

Full Text Available Part one discusses some principal mite pests in agroecosystems and urban horticulturein European countries, Serbia and its neighbouring countries focusing primarily on issueswith regard to plant production, novel methods and approaches in applied acaralogy. Parttwo displays some major properties of acaricides inhibiting respiration, growth and developmentand other synthetic substances with acaricide action on the market in the last decadeof the 20th century and the first decade of the 21st century. Also some products of naturalorigin (azadirachtin, oils, micoacaricides are said to be gaining in importance. Issues withregard to the fact that mites can readily develop resistance to acardicides are discussed anda survey on the results of biochemical, physiological and genetical causes of resistance areanalyzed. Some basic principles of biological control of phytophagous mites and modernadvances and approaches are discussed as well as current knowledge on host plant resistanceto mites. Eventually, the possibility of using a combination of selective acaricides andbiological control agents is discussed but also the inclusion of other modes of control (agriculturalpractices and physical measures expected to contribute to an integrated managementof pest populations.

The current status of theoretically based approaches to the prediction of the critical heat flux in flow boiling

International Nuclear Information System (INIS)

Weisman, J.

1991-01-01

This paper reports on the phenomena governing the critical heat flux in flow boiling. Inducts which vary with the flow pattern. Separate models are needed for dryout in annular flow, wall overheating in plug or slug flow and formation of a vapor blanket in dispersed flow. The major theories and their current status are described for the annular and dispersed regions. The need for development of the theoretical approach in the plug and slug flow region is indicated

Lauric acid as feed additive - An approach to reducing Campylobacter spp. in broiler meat.

Science.gov (United States)

Zeiger, Katrin; Popp, Johanna; Becker, André; Hankel, Julia; Visscher, Christian; Klein, Guenter; Meemken, Diana

2017-01-01

The increasing prevalence of Campylobacter spp. within broiler populations is a major problem for food safety and consumer protection worldwide. In vitro studies could already demonstrate that Campylobacter spp. are susceptible to lauric acid. The purpose of this study was to examine in vivo the influence of lauric acid as a feed additive on slaughter parameters, muscle fatty acid profile, meat quality traits and the reduction of Campylobacter coli in inoculated meat of Ross 308 (R308) and Hubbard JA 757 (HJA) broilers in three independent trials (n = 3). Although slaughter parameters did not show any significant differences, the fatty acid profile of both breeds revealed significantly higher lauric acid concentrations (P meat quality traits showed no differences in the R308 breed (P > 0.05), but HJA test broilers had higher values for drip loss, electrical conductivity, CIE color values L* and b*, and lower pH values. The inoculation trials of R308 showed that initial bacterial loads of 5.9 log10 cfu/g were reduced during six days of storage (4°C) to approximately 4.3 log10 cfu/g in the control groups compared to 3.5 log10 cfu/g in the treatment groups (P = 0.0295), which could be due to antimicrobial effects of lauric acid within the muscle. This study therefore suggests that lauric acid as a feed additive has the potential to improve food safety by reducing the numbers of Campylobacter coli in broiler meat. However, this effect seems to be dependent on the breed determining the feed intake capacity, the fat deposition and therefore the ability to incorporate lauric acid in the muscle.

Lauric acid as feed additive - An approach to reducing Campylobacter spp. in broiler meat.

Directory of Open Access Journals (Sweden)

Katrin Zeiger

Full Text Available The increasing prevalence of Campylobacter spp. within broiler populations is a major problem for food safety and consumer protection worldwide. In vitro studies could already demonstrate that Campylobacter spp. are susceptible to lauric acid. The purpose of this study was to examine in vivo the influence of lauric acid as a feed additive on slaughter parameters, muscle fatty acid profile, meat quality traits and the reduction of Campylobacter coli in inoculated meat of Ross 308 (R308 and Hubbard JA 757 (HJA broilers in three independent trials (n = 3. Although slaughter parameters did not show any significant differences, the fatty acid profile of both breeds revealed significantly higher lauric acid concentrations (P 0.05, but HJA test broilers had higher values for drip loss, electrical conductivity, CIE color values L* and b*, and lower pH values. The inoculation trials of R308 showed that initial bacterial loads of 5.9 log10 cfu/g were reduced during six days of storage (4°C to approximately 4.3 log10 cfu/g in the control groups compared to 3.5 log10 cfu/g in the treatment groups (P = 0.0295, which could be due to antimicrobial effects of lauric acid within the muscle. This study therefore suggests that lauric acid as a feed additive has the potential to improve food safety by reducing the numbers of Campylobacter coli in broiler meat. However, this effect seems to be dependent on the breed determining the feed intake capacity, the fat deposition and therefore the ability to incorporate lauric acid in the muscle.

Bile acids in regulation of intestinal physiology.

LENUS (Irish Health Repository)

Keating, Niamh

2009-10-01

In addition to their roles in facilitating lipid digestion and absorption, bile acids are recognized as important regulators of intestinal function. Exposure to bile acids can dramatically influence intestinal transport and barrier properties; in recent years, they have also become appreciated as important factors in regulating cell growth and survival. Indeed, few cells reside within the intestinal mucosa that are not altered to some degree by exposure to bile acids. The past decade saw great advances in the knowledge of how bile acids exert their actions at the cellular and molecular levels. In this review, we summarize the current understanding of the role of bile acids in regulation of intestinal physiology.

Conversion of beta-methylbutyric acid to beta-hydroxy-beta-methylbutyric acid by Galactomyces reessii.

OpenAIRE

Lee, I Y; Nissen, S L; Rosazza, J P

1997-01-01

beta-Hydroxy-beta-methylbutyric acid (HMB) has been shown to increase strength and lean mass gains in humans undergoing resistance-exercise training. HMB is currently marketed as a calcium salt of HMB, and thus, environmentally sound and inexpensive methods of manufacture are being sought. This study investigates the microbial conversion of beta-methylbutyric acid (MBA) to HMB by cultures of Galactomyces reessii. Optimal concentrations of MBA were in the range of 5 to 20 g/liter for HMB produ...

Antibacterial Free Fatty Acids and Monoglycerides: Biological Activities, Experimental Testing, and Therapeutic Applications

Science.gov (United States)

Yoon, Bo Kyeong; Jackman, Joshua A.; Valle-González, Elba R.

2018-01-01

Antimicrobial lipids such as fatty acids and monoglycerides are promising antibacterial agents that destabilize bacterial cell membranes, causing a wide range of direct and indirect inhibitory effects. The goal of this review is to introduce the latest experimental approaches for characterizing how antimicrobial lipids destabilize phospholipid membranes within the broader scope of introducing current knowledge about the biological activities of antimicrobial lipids, testing strategies, and applications for treating bacterial infections. To this end, a general background on antimicrobial lipids, including structural classification, is provided along with a detailed description of their targeting spectrum and currently understood antibacterial mechanisms. Building on this knowledge, different experimental approaches to characterize antimicrobial lipids are presented, including cell-based biological and model membrane-based biophysical measurement techniques. Particular emphasis is placed on drawing out how biological and biophysical approaches complement one another and can yield mechanistic insights into how the physicochemical properties of antimicrobial lipids influence molecular self-assembly and concentration-dependent interactions with model phospholipid and bacterial cell membranes. Examples of possible therapeutic applications are briefly introduced to highlight the potential significance of antimicrobial lipids for human health and medicine, and to motivate the importance of employing orthogonal measurement strategies to characterize the activity profile of antimicrobial lipids. PMID:29642500

Synthesis of derivatives of tetronic acid and pulvinic acid. Total synthesis of norbadione A

International Nuclear Information System (INIS)

Mallinger, A.

2008-11-01

When vegetables like mushrooms are contaminated by radioactive caesium 137, this radioactive caesium is associated to norbadione A, a natural pigment present in two mushroom species and which can be used as a caesium decorporation agent or maybe as protection agent against ionizing radiations. Within this perspective, this research report describes the biosynthesis and the structure and properties of the norbadione A and of pulvinic acids (physicochemical properties, anti-oxidizing properties). Then, it presents the various tetronic acids (3-acyl-, 3-alkyl-, 3-alkoxy-, 3-aryl-tetronic acids and non 3-substituted tetronic acids), their synthesis path as they are described in the literature, and presents a new synthesis approach using a tandem reaction (with different esters or hydroxy esters) and the synthesis of tetronic acids. The author also proposes a new synthesis way for methyl pulvinates, and finally reports the work on the development of a total synthesis of the norbadione A

Magnetic Field of Conductive Objects as Superposition of Elementary Eddy Currents and Eddy Current Tomography

Science.gov (United States)

Sukhanov, D. Ya.; Zav'yalova, K. V.

2018-03-01

The paper represents induced currents in an electrically conductive object as a totality of elementary eddy currents. The proposed scanning method includes measurements of only one component of the secondary magnetic field. Reconstruction of the current distribution is performed by deconvolution with regularization. Numerical modeling supported by the field experiments show that this approach is of direct practical relevance.

Understanding Analysis Macroscopic, microscopic, and Acid-Base Titration Symbolic Student Class XI Science High School and Improvement Efforts Microscopy Approach

Directory of Open Access Journals (Sweden)

Putu Indrayani

2014-06-01

Full Text Available Analisis Pemahaman Makroskopik, Mikroskopik, dan Simbolik Titrasi Asam-Basa Siswa Kelas XI IPA SMA serta Upaya Perbaikannya dengan Pendekatan Mikroskopik Abstract: This study aims to determine: (1 the level of understanding of the macroscopic, microscopic and symbolic students; (2 the error understanding of macroscopic, microscopic and symbolic students; (3 the effectiveness of the microscopic approach in an effort to improve students' ability to solve the problems macroscopic, symbolic and microscopic material acid-base titration. This research uses descriptive research design and quasi-experimental research design. Data research is the understanding of macroscopic, symbolic and microscopic students on the material acid-base titration. Student comprehension test measured with instruments that include: (1 macroscopic comprehension tests, (2 test the understanding of symbolic, and (3 understanding of the microscopic tests. Content validity was tested by a team of experts and the reliability of test questions macroscopic and microscopic calculated using the Spearman-Brown while reliability symbolic test item was calculated using Cronbach's Alpha. Data were analyzed using descriptive analysis and statistical tests using Anacova. Results of the study are as follows. (1 The level of understanding of the macroscopic students is high, while the symbolic and microscopic levels of understanding of students is very low. (2 Errors identified macroscopic understanding is that students do not understand that the color shown by indicators related to the nature of the solution. Symbolic understanding of the identified errors are: (i the student can not write ionization reaction; and (ii students can not choose the formula used to calculate the pH of the solution. Errors identified microscopic understanding is that students can not provide a microscopic picture of a solution of a strong acid, strong base, weak acid, weak base, and salt solutions because they do

MELiSSA Food Characterization general approach and current status

Science.gov (United States)

Weihreter, Martin; Chaerle, Laury; Secco, Benjamin; Molders, Katrien; van der Straeten, Dominique; Duliere, Eric; Pieters, Serge; Maclean, Heather; Dochain, Denis; Quinet, Muriel; Lutts, Stanley; Graham, Thomas; Stasiak, Michael; Rondeau Vuk, Theresa; Zheng, Youbin; Dixon, Mike; Laniau, Martine; Larreture, Alain; Timsit, Michel; Aronne, Giovanna; Barbieri, Giancarlo; Buonomo, Roberta; Veronica; Paradiso, Roberta; de Pascale, Stafania; Galbiati, Massimo; Troia, A. R.; Nobili, Matteo; Bucchieri, Lorenzo; Page, Valérie; Feller, Urs; Lasseur, Christophe

. Available MELiSSA closed environment crop growth data were used to develop a first photosynthetic model representing the basic carbon fixation mechanisms. This model will be further elaborated in the course of this study to predict yield, oxygen production and transpi-ration. As an ultimate goal the model is intended to simulate the composition of the different plant organs (root, shoot, fruit/seed or tuber) for each crop under various conditions. For the validation of this model an extensive amount of data sets are needed. Current plant growth bench test setups will provide part of the required data. To gain more precise and detailed datasets, a highly closed plant growth chamber (Plant Characterization Unit, PCU) is under development. The PCU will provide accurate mass balances for carbon, water, oxygen and other elements with statistical reliability. This reliability is achieved through a high degree of closure and environment homogeneity. The PCU will also provide data for the above described plant characterization studies. The general work approach, the current status and future steps will be illustrated.

Solubility of fumaric acid and its monosodium salt

NARCIS (Netherlands)

Roa Engel, C.A.; Horst, J.H. ter; Pieterse, M.; Wielen, L.A.M. van der; Straathof, A.J.J.

2013-01-01

Fumaric acid is a dicarboxylic acid applied in food industry and in some polymers. Currently, its fermentative production from renewable resources is receiving much attention, and crystallization is used to recover it. To determine the window of operation for crystallization from multicomponent

Improving itaconic acid production through genetic engineering of an industrial Aspergillus terreus strain.

Science.gov (United States)

Huang, Xuenian; Lu, Xuefeng; Li, Yueming; Li, Xia; Li, Jian-Jun

2014-08-11

Itaconic acid, which has been declared to be one of the most promising and flexible building blocks, is currently used as monomer or co-monomer in the polymer industry, and produced commercially by Aspergillus terreus. However, the production level of itaconic acid hasn't been improved in the past 40 years, and mutagenesis is still the main strategy to improve itaconate productivity. The genetic engineering approach hasn't been applied in industrial A. terreus strains to increase itaconic acid production. In this study, the genes closely related to itaconic acid production, including cadA, mfsA, mttA, ATEG_09969, gpdA, ATEG_01954, acoA, mt-pfkA and citA, were identified and overexpressed in an industrial A. terreus strain respectively. Overexpression of the genes cadA (cis-aconitate decarboxylase) and mfsA (Major Facilitator Superfamily Transporter) enhanced the itaconate production level by 9.4% and 5.1% in shake flasks respectively. Overexpression of other genes showed varied effects on itaconate production. The titers of other organic acids were affected by the introduced genes to different extent. Itaconic acid production could be improved through genetic engineering of the industrially used A. terreus strain. We have identified some important genes such as cadA and mfsA, whose overexpression led to the increased itaconate productivity, and successfully developed a strategy to establish a highly efficient microbial cell factory for itaconate protuction. Our results will provide a guide for further enhancement of the itaconic acid production level through genetic engineering in future.

Utilization of oriented crystal growth for screening of aromatic carboxylic acids cocrystallization with urea

Science.gov (United States)

Przybyłek, Maciej; Ziółkowska, Dorota; Kobierski, Mirosław; Mroczyńska, Karina; Cysewski, Piotr

2016-01-01

The possibility of molecular complex formation in the solid state of urea with benzoic acid analogues was measured directly on the crystallite films deposited on the glass surface using powder X-ray diffractometry (PXRD). Obtained solid mixtures were also analyzed using Fourier transform infrared spectroscopy (FTIR). The simple droplet evaporation method was found to be efficient, robust, fast and cost-preserving approach for first stage cocrystal screening. Additionally, the application of orientation effect to cocrystal screening simplifies the analysis due to damping of majority of diffraction signals coming from coformers. During validation phase the proposed approach successfully reproduced both positive cases of cocrystallization (urea:salicylic acid and urea:4-hydroxy benzoic acid) as well as pairs of co-formers immiscible in the solid state (urea:benzoic acid and urea:acetylsalicylic acids). Based on validated approach new cocrystals of urea were identified in complexes with 3-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid and 3,5-dihydroxybenzoic acid. In all cases formation of multicomponent crystal phase was confirmed by the appearance of new reflexes on the diffraction patterns and FTIR absorption band shifts of O-H and N-H groups.

A geochemical approach to the restoration plans for the Odiel River basin (SW Spain), a watershed deeply polluted by acid mine drainage.

Science.gov (United States)

Macías, Francisco; Pérez-López, Rafael; Caraballo, Manuel A; Sarmiento, Aguasanta M; Cánovas, Carlos R; Nieto, Jose M; Olías, Manuel; Ayora, Carlos

2017-02-01

The Odiel River Basin (SW Spain) drains the central part of the Iberian Pyrite Belt (IPB), a world-class example of sulfide mining district and concomitantly of acid mine drainage (AMD) pollution. The severe AMD pollution and the incipient state of remediation strategies implemented in this region, coupled with the proximity of the deadline for compliance with the European Water Framework Directive (WFD), urge to develop a restoration and water resources management strategy. Furthermore, despite the presence of some reservoirs with acid waters in the Odiel basin, the construction of the Alcolea water reservoir has already started. On the basis of the positive results obtained after more than 10 years of developing a specific passive remediation technology (dispersed alkaline substrate (DAS)) for the highly polluted AMD of this region, a restoration strategy is proposed. The implementation of 13 DAS treatment plants in selected acid discharges along the Odiel and Oraque sub-basins and other restoration measurements of two acidic creeks is proposed as essential to obtain a good water quality in the future Alcolea reservoir. This restoration strategy is also suggested as an economically and environmentally sustainable approach to the extreme metal pollution affecting the waters of the region and could be considered the starting point for the future compliance with the WFD in the Odiel River Basin.

From Medicinal Chemistry to Human Health: Current Approaches to Drug Discovery for Cancer and Neglected Tropical Diseases

Directory of Open Access Journals (Sweden)

LEONARDO G. FERREIRA

2018-02-01

Full Text Available ABSTRACT Scientific and technological breakthroughs have compelled the current players in drug discovery to increasingly incorporate knowledge-based approaches. This evolving paradigm, which has its roots attached to the recent advances in medicinal chemistry, molecular and structural biology, has unprecedentedly demanded the development of up-to-date computational approaches, such as bio- and chemo-informatics. These tools have been pivotal to catalyzing the ever-increasing amount of data generated by the molecular sciences, and to converting the data into insightful guidelines for use in the research pipeline. As a result, ligand- and structure-based drug design have emerged as key pathways to address the pharmaceutical industry’s striking demands for innovation. These approaches depend on a keen integration of experimental and molecular modeling methods to surmount the main challenges faced by drug candidates - in vivo efficacy, pharmacodynamics, metabolism, pharmacokinetics and safety. To that end, the Laboratório de Química Medicinal e Computacional (LQMC of the Universidade de São Paulo has developed forefront research on highly prevalent and life-threatening neglected tropical diseases and cancer. By taking part in global initiatives for pharmaceutical innovation, the laboratory has contributed to the advance of these critical therapeutic areas through the use of cutting-edge strategies in medicinal chemistry.

Technological and economic potential of poly(lactic acid) and lactic acid derivatives

Energy Technology Data Exchange (ETDEWEB)

Datta, R.; Tsai, S.P.; Bonsignore, P.; Moon, S.H.; Frank, J.R.

1993-10-01

Lactic acid has been an intermediate-volume specialty chemical (world production {approximately}40,000 tons/yr) used in a wide range of food processing and industrial applications. lactic acid h,as the potential of becoming a very large volume, commodity-chemical intermediate produced from renewable carbohydrates for use as feedstocks for biodegradable polymers, oxygenated chemicals, plant growth regulators, environmentally friendly ``green`` solvents, and specially chemical intermediates. In the past, efficient and economical technologies for the recovery and purification of lactic acid from crude fermentation broths and the conversion of tactic acid to the chemical or polymer intermediates had been the key technology impediments and main process cost centers. The development and deployment of novel separations technologies, such as electrodialysis (ED) with bipolar membranes, extractive distillations integrated with fermentation, and chemical conversion, can enable low-cost production with continuous processes in large-scale operations. The use of bipolar ED can virtually eliminate the salt or gypsum waste produced in the current lactic acid processes. In this paper, the recent technical advances in tactic and polylactic acid processes are discussed. The economic potential and manufacturing cost estimates of several products and process options are presented. The technical accomplishments at Argonne National Laboratory (ANL) and the future directions of this program at ANL are discussed.

Current concepts and future approaches to vestibular rehabilitation.

Science.gov (United States)

Tjernström, Fredrik; Zur, Oz; Jahn, Klaus

2016-04-01

Over the last decades methods of vestibular rehabilitation to enhance adaptation to vestibular loss, habituation to changing sensory conditions, and sensory reweighting in the compensation process have been developed. However, the use of these techniques still depends to a large part on the educational background of the therapist. Individualized assessment of deficits and specific therapeutic programs for different disorders are sparse. Currently, vestibular rehabilitation is often used in an unspecific way in dizzy patients irrespective of the clinical findings. When predicting the future of vestibular rehabilitation, it is tempting to foretell advances in technology for assessment and treatment only, but the current intense exchange between clinicians and basic scientists also predicts advances in truly understanding the complex interactions between the peripheral senses and central adaptation mechanisms. More research is needed to develop reliable techniques to measure sensory dependence and to learn how this knowledge can be best used--by playing off the patient's sensory strength or working on the weakness. To be able using the emerging concepts, the neuro-otological community must strive to educate physicians, physiotherapists and nurses to perform the correct examinations for assessment of individual deficits and to look for factors that might impede rehabilitation.

Exchange processes at geosphere-biosphere interface. Current SKB approach and example of coupled hydrological-ecological approach

International Nuclear Information System (INIS)

Woerman, Anders

2003-09-01

The design of the repository for final disposal of spent nuclear fuel proposed by SKB is based on a multi-barrier system, in which the geosphere and biosphere are the utmost barrier surrounding the engineer barriers. This report briefly reviews the current approach taken by SKB to account for hydrological and ecological processes at the geosphere-biosphere interface (GBI) and their future plans in this area. A simple analysis was performed to shift the focus of performance assessment involving geosphere-biosphere interface modelling from the very simplistic assumption that the quaternary sediments are bypassed to one in which a more detailed model for sub-surface flows is included. This study indicated that, for many assumed ecosystem descriptions, the presence of the GBI leads to lower maximum doses to individual humans compared to a case when the GBI is neglected. This effect is due to the additional 'barrier' offered by the GBI. The main exposure pathways were assumed to occur through the food web. However, particularly the leakage on land through the stream-network and lakes can lead to higher doses due to ecosystem interaction with arable land. A scenario that gives particularly long duration of doses occurs due to land rise and with the transformation of the former bay and lake bed sediments into agricultural land. This effect is due to the significant retention or accumulation in aquatic sediment, which causes high activities to build up with time. Particularly, in combination with changing conditions in climate, humans life-style or geographic conditions (land rise, deforestation,etc.) doses to individual humans can be large

Eddy current analysis by BEM utilizing loop electric and surface magnetic currents as unknowns

International Nuclear Information System (INIS)

Ishibashi, Kazuhisa

2002-01-01

The surface integral equations whose unknowns are the surface electric and magnetic currents are widely used in eddy current analysis. However, when the skin depth is thick, computational error is increased especially in obtaining electromagnetic fields near the edge of the conductor. In order to obtain the electromagnetic field accurately, we propose an approach to solve surface integral equations utilizing loop electric and surface magnetic currents as unknowns. (Author)

Current approaches to nuclear power plant life management in Japan

International Nuclear Information System (INIS)

Noda, T.; Tajima, K.; Ishikawa, M.; Koyama, M.

2002-01-01

extracted additional maintenance measures and incorporated them into their long-term maintenance plans, thereby reinforcing their current maintenance activities. Considering the latest information including domestic and overseas operating experiences and knowledge of academics and experts consigned by the Minister of Economy, Trade and Industry (METI), the Nuclear and Industry Safety Agency (NISA) of the METI reviewed and studied the technical evaluation and long-term maintenance plans of these electric utility companies. This paper describes the outlines of the NISA's report and related activities on current approaches to cope with the ageing of nuclear power plants in Japan. (Note) In 2001, the MITI was reorganized to the Ministry of Economy, Trade and Industry (METI). (author)

Conformational analysis of glutamic acid: a density functional approach using implicit continuum solvent model.

Science.gov (United States)

Turan, Başak; Selçuki, Cenk

2014-09-01

Amino acids are constituents of proteins and enzymes which take part almost in all metabolic reactions. Glutamic acid, with an ability to form a negatively charged side chain, plays a major role in intra and intermolecular interactions of proteins, peptides, and enzymes. An exhaustive conformational analysis has been performed for all eight possible forms at B3LYP/cc-pVTZ level. All possible neutral, zwitterionic, protonated, and deprotonated forms of glutamic acid structures have been investigated in solution by using polarizable continuum model mimicking water as the solvent. Nine families based on the dihedral angles have been classified for eight glutamic acid forms. The electrostatic effects included in the solvent model usually stabilize the charged forms more. However, the stability of the zwitterionic form has been underestimated due to the lack of hydrogen bonding between the solute and solvent; therefore, it is observed that compact neutral glutamic acid structures are more stable in solution than they are in vacuum. Our calculations have shown that among all eight possible forms, some are not stable in solution and are immediately converted to other more stable forms. Comparison of isoelectronic glutamic acid forms indicated that one of the structures among possible zwitterionic and anionic forms may dominate over the other possible forms. Additional investigations using explicit solvent models are necessary to determine the stability of charged forms of glutamic acid in solution as our results clearly indicate that hydrogen bonding and its type have a major role in the structure and energy of conformers.

Removal of Arsenic Using Acid/Metal-Tolerant Sulfate Reducing Bacteria: A New Approach for Bioremediation of High-Arsenic Acid Mine Waters

Directory of Open Access Journals (Sweden)

Jennyfer Serrano

2017-12-01

Full Text Available Fluvial sediments, soils, and natural waters in northern Chile are characterized by high arsenic (As content. Mining operations in this area are potential sources of As and other metal contaminants, due to acid mine drainage (AMD generation. Sulfate Reducing Bacteria (SRB has been used for the treatment of AMD, as they allow for the reduction of sulfate, the generation of alkalinity, and the removal of dissolved heavy metals and metalloids by precipitation as insoluble metal sulfides. Thus, SRB could be used to remove As and other heavy metals from AMD, however the tolerance of SRB to high metal concentrations and low pH is limited. The present study aimed to quantify the impact of SRB in As removal under acidic and As-Fe-rich conditions. Our results show that SRB tolerate low pH (up to 3.5 and high concentrations of As (~3.6 mg·L−1. Batch experiments showed As removal of up to 73%, Iron (Fe removal higher than 78% and a neutralization of pH from acidic to circum-neutral conditions (pH 6–8. In addition, XRD analysis showed the dominance of amorphous minerals, while Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM-EDX analysis showed associations between As, Fe, and sulfur, indicating the presence of Fe-S-As compounds or interaction of As species with amorphous and/or nanocrystalline phases by sorption processes. These results indicate that the As removal was mediated by acid/metal-tolerant SRB and open the potential for the application of new strains of acid/metal-tolerant SRB for the remediation of high-As acid mine waters.

Time development of electric fields and currents in space plasmas

Directory of Open Access Journals (Sweden)

A. T. Y. Lui

2006-05-01

Full Text Available Two different approaches, referred to as Bu and Ej, can be used to examine the time development of electric fields and currents in space plasmas based on the fundamental laws of physics. From the Bu approach, the required equation involves the generalized Ohm's law with some simplifying assumptions. From the Ej approach, the required equation can be derived from the equation of particle motion, coupled self-consistently with Maxwell's equation, and the definition of electric current density. Recently, some strong statements against the Ej approach have been made. In this paper, we evaluate these statements by discussing (1 some limitations of the Bu approach in solving the time development of electric fields and currents, (2 the procedure in calculating self-consistently the time development of the electric current in space plasmas without taking the curl of the magnetic field in some cases, and (3 the dependency of the time development of magnetic field on electric current. It is concluded that the Ej approach can be useful to understand some magnetospheric problems. In particular, statements about the change of electric current are valid theoretical explanations of change in magnetic field during substorms.

Decomposition of environmentally persistent perfluorooctanoic acid in water by photochemical approaches.

Science.gov (United States)

Hori, Hisao; Hayakawa, Etsuko; Einaga, Hisahiro; Kutsuna, Shuzo; Koike, Kazuhide; Ibusuki, Takashi; Kiatagawa, Hiroshi; Arakawa, Ryuichi

2004-11-15

The decomposition of persistent and bioaccumulative perfluorooctanoic acid (PFOA) in water by UV-visible light irradiation, by H202 with UV-visible light irradiation, and by a tungstic heteropolyacid photocatalyst was examined to develop a technique to counteract stationary sources of PFOA. Direct photolysis proceeded slowly to produce CO2, F-, and short-chain perfluorocarboxylic acids. Compared to the direct photolysis, H2O2 was less effective in PFOA decomposition. On the other hand, the heteropolyacid photocatalyst led to efficient PFOA decomposition and the production of F- ions and CO2. The photocatalyst also suppressed the accumulation of short-chain perfluorocarboxylic acids in the reaction solution. PFOA in the concentrations of 0.34-3.35 mM, typical of those in wastewaters after an emulsifying process in fluoropolymer manufacture, was completely decomposed by the catalyst within 24 h of irradiation from a 200-W xenon-mercury lamp, with no accompanying catalyst degradation, permitting the catalyst to be reused in consecutive runs. Gas chromatography/mass spectrometry (GC/MS) measurements showed no trace of environmentally undesirable species such as CF4, which has a very high global-warming potential. When the (initial PFOA)/(initial catalyst) molar ratio was 10: 1, the turnover number for PFOA decomposition reached 4.33 over 24 h of irradiation.

Amino acid derivatives are substrates or non-transported inhibitors of the amino acid transporter PAT2 (slc36a2).

Science.gov (United States)

Edwards, Noel; Anderson, Catriona M H; Gatfield, Kelly M; Jevons, Mark P; Ganapathy, Vadivel; Thwaites, David T

2011-01-01

The H(+)-coupled amino acid transporter PAT2 (SLC36A2) transports the amino acids proline, glycine, alanine and hydroxyproline. A physiological role played by PAT2 in amino acid reabsorption in the renal proximal tubule is demonstrated by mutations in SLC36A2 that lead to an iminoglycinuric phenotype (imino acid and glycine uria) in humans. A number of proline, GABA and tryptophan derivatives were examined to determine if they function either as transported substrates or non-transported inhibitors of PAT2. The compounds were investigated following heterologous expression of rat PAT2 in Xenopus laevis oocytes. PAT2 function was characterised by: radiotracer uptake and competition (cis-inhibition) studies; radiotracer efflux and trans-stimulation; and measurement of substrate-induced positive inward current by two-electrode voltage-clamp. In general, the proline derivatives appeared to be transported substrates and the relative ability to induce current flow was closely related to the inhibitory effects on PAT2-mediated l-[(3)H]proline uptake. In contrast, certain heterocyclic GABA derivatives (e.g. l-pipecolic acid) were translocated only slowly. Finally, the tryptophan derivatives inhibited PAT2 function but did not undergo transport. l-Proline uptake was inhibited by 5-hydroxy-l-tryptophan (IC(50) 1.6±0.4mM), α-methyl-d,l-tryptophan (3.5±1.5mM), l-tryptophan, 1-methyl-l-tryptophan and indole-3-propionic acid. Although neither 5-hydroxy-l-tryptophan nor α-methyl-d,l-tryptophan were able to elicit inward current in PAT2-expressing oocytes both reduced the current evoked by l-proline. 5-Hydroxy-l-tryptophan and α-methyl-d,l-tryptophan were unable to trans-stimulate l-proline efflux from PAT2-expressing oocytes, confirming that the two compounds act as non-transported blockers of PAT2. These two tryptophan derivatives should prove valuable experimental tools in future investigations of the physiological roles of PAT2. Copyright © 2010 Elsevier B.V. All rights

Cross-current leaching of indium from end-of-life LCD panels

Energy Technology Data Exchange (ETDEWEB)

Rocchetti, Laura; Amato, Alessia; Fonti, Viviana [Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona (Italy); Ubaldini, Stefano [Institute of Environmental Geology and Geoengineering IGAG, National Research Council, Via Salaria km 29300, 00015 Montelibretti, Rome (Italy); De Michelis, Ida [Department of Industrial Engineering, Information and Economy, University of L’Aquila, Via Giovanni Gronchi 18, 67100, Zona industriale di Pile, L’Aquila (Italy); Kopacek, Bernd [ISL Kopacek KG, Beckmanngasse 51, 1140 Wien (Austria); Vegliò, Francesco [Department of Industrial Engineering, Information and Economy, University of L’Aquila, Via Giovanni Gronchi 18, 67100, Zona industriale di Pile, L’Aquila (Italy); Beolchini, Francesca, E-mail: f.beolchini@univpm.it [Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona (Italy)

2015-08-15

Graphical abstract: Display Omitted - Highlights: • End-of-life LCD panels represent a source of indium. • Several experimental conditions for indium leaching have been assessed. • Indium is completely extracted with 2 M sulfuric acid at 80 °C for 10 min. • Cross-current leaching improves indium extraction and operating costs are lowered. • Benefits to the environment come from reduction of CO{sub 2} emissions and reagents use. - Abstract: Indium is a critical element mainly produced as a by-product of zinc mining, and it is largely used in the production process of liquid crystal display (LCD) panels. End-of-life LCDs represent a possible source of indium in the field of urban mining. In the present paper, we apply, for the first time, cross-current leaching to mobilize indium from end-of-life LCD panels. We carried out a series of treatments to leach indium. The best leaching conditions for indium were 2 M sulfuric acid at 80 °C for 10 min, which allowed us to completely mobilize indium. Taking into account the low content of indium in end-of-life LCDs, of about 100 ppm, a single step of leaching is not cost-effective. We tested 6 steps of cross-current leaching: in the first step indium leaching was complete, whereas in the second step it was in the range of 85–90%, and with 6 steps it was about 50–55%. Indium concentration in the leachate was about 35 mg/L after the first step of leaching, almost 2-fold at the second step and about 3-fold at the fifth step. Then, we hypothesized to scale up the process of cross-current leaching up to 10 steps, followed by cementation with zinc to recover indium. In this simulation, the process of indium recovery was advantageous from an economic and environmental point of view. Indeed, cross-current leaching allowed to concentrate indium, save reagents, and reduce the emission of CO{sub 2} (with 10 steps we assessed that the emission of about 90 kg CO{sub 2}-Eq. could be avoided) thanks to the recovery of indium

Alteration of the phospho- or neutral lipid content and fatty acid composition in Listeria monocytogenes due to acid adaptation mechanisms for hydrochloric, acetic and lactic acids at pH 5.5 or benzoic acid at neutral pH.

Science.gov (United States)

Mastronicolis, Sofia K; Berberi, Anita; Diakogiannis, Ioannis; Petrova, Evanthia; Kiaki, Irene; Baltzi, Triantafillia; Xenikakis, Polydoros

2010-10-01

This study provides a first approach to observe the effects on Listeria monocytogenes of cellular exposure to acid stress at low or neutral pH, notably how phospho- or neutral lipids are involved in this mechanism, besides the fatty acid profile alteration. A thorough investigation of the composition of polar and neutral lipids from L. monocytogenes grown at pH 5.5 in presence of hydrochloric, acetic and lactic acids, or at neutral pH 7.3 in presence of benzoic acid, is described relative to cells grown in acid-free medium. The results showed that only low pH values enhance the antimicrobial activity of an acid. We suggest that, irrespective of pH, the acid adaptation response will lead to a similar alteration in fatty acid composition [decreasing the ratio of branched chain/saturated straight fatty acids of total lipids], mainly originating from the neutral lipid class of adapted cultures. Acid adaptation in L. monocytogenes was correlated with a decrease in total lipid phosphorus and, with the exception of cells adapted to benzoic acid, this change in the amount of phosphorus reflected a higher content of the neutral lipid class. Upon acetic or benzoic acid stress the lipid phosphorus proportion was analysed in the main phospholipids present: cardiolipin, phosphatidylglycerol, phosphoaminolipid and phosphatidylinositol. Interestingly only benzoic acid had a dramatic effect on the relative quantities of these four phospholipids.

Microbial Propionic Acid Production

Directory of Open Access Journals (Sweden)

R. Axayacatl Gonzalez-Garcia

2017-05-01

Full Text Available Propionic acid (propionate is a commercially valuable carboxylic acid produced through microbial fermentation. Propionic acid is mainly used in the food industry but has recently found applications in the cosmetic, plastics and pharmaceutical industries. Propionate can be produced via various metabolic pathways, which can be classified into three major groups: fermentative pathways, biosynthetic pathways, and amino acid catabolic pathways. The current review provides an in-depth description of the major metabolic routes for propionate production from an energy optimization perspective. Biological propionate production is limited by high downstream purification costs which can be addressed if the target yield, productivity and titre can be achieved. Genome shuffling combined with high throughput omics and metabolic engineering is providing new opportunities, and biological propionate production is likely to enter the market in the not so distant future. In order to realise the full potential of metabolic engineering and heterologous expression, however, a greater understanding of metabolic capabilities of the native producers, the fittest producers, is required.

Rational Discovery of (+) (S) Abscisic Acid as a Potential Antifungal Agent: a Repurposing Approach.

Science.gov (United States)

Khedr, Mohammed A; Massarotti, Alberto; Mohamed, Maged E

2018-06-04

Fungal infections are spreading widely worldwide, and the types of treatment are limited due to the lack of diverse therapeutic agents and their associated side effects and toxicity. The discovery of new antifungal classes is vital and critical. We discovered the antifungal activity of abscisic acid through a rational drug design methodology that included the building of homology models for fungal chorismate mutases and a pharmacophore model derived from a transition state inhibitor. Ligand-based virtual screening resulted in some hits that were filtered using molecular docking and molecular dynamic simulations studies. Both in silico methods and in vitro antifungal assays were used as tools to select and validate the abscisic acid repurposing. Abscisic acid inhibition assays confirmed the inhibitory effect of abscisic acid on chorismate mutase through the inhibition of phenylpyruvate production. The repositioning of abscisic acid, the well-known and naturally occurring plant growth regulator, as a potential antifungal agent because of its suggested action as an inhibitor to several fungal chorismate mutases was the main result of this work.

Folic acid fortification and public health: report on threshold doses above which unmetabolised folic acid appear in serum.

LENUS (Irish Health Repository)

Sweeney, Mary Rose

2007-01-01

BACKGROUND: All flour in the USA is fortified with folic acid at a level of 140 microg\\/100 g which is estimated to supply an extra 100 microg daily to the average diet. Some researchers have advocated that this be increased to double and even four times this amount. Based on previous research these higher levels are likely to lead to the appearance of unmetabolised vitamin in the circulation, which may have safety implications for sub-groups of the population. The UK and the Republic of Ireland will likely introduce mandatory fortification also in the next year or so. The aim of this study was to capture the short-term effect of folic acid fortification on unmetabolised folic acid in serum after chronic consumption of folic acid. METHODS: After pre-saturation with 400 microg folic acid supplements daily for 14-weeks, healthy folate replete adults (n = 20) consumed folic acid fortified bread, at three different levels (400 microg, 200 microg, 100 microg) over a period of one week each. The dose was administered in two-equal sized slices consumed at 09.00 hrs and 13.00 hrs. Serum samples for total folate and folic acid were collected at baseline, after 14-weeks of supplementation, and pre and post (at 1, 2, 3 and 4 hours) each dose tested. RESULTS: Unmetabolised folic acid was detected after the 14-week supplementation period. Folic acid was not detected in either the 200 microg or 100 microg (current US regime) doses tested but was present at the highest level (400 microg) tested. CONCLUSION: Our findings suggest that persons exposed to the current US fortification programme supplying an average of 100 microg per day or less are unlikely to have unmetabolised folic acid in serum. It also seems that daily consumption of the higher level of 200 microg or less is unlikely to be problematic. Increasing the level however to 400 microg on the other hand is likely to lead to unmetabolised folic acid appearance.

A Current Look at Phenylketonuria (PKU).

Science.gov (United States)

Fischer, Margaret

Research was reviewed on the current status of phenylketonuria, an hereditary amino acid metabolic disorder that can cause severe mental retardation, physical complications, and emotional difficulties if not detected and treated early in childhood. A majority of the research cited was published in the 1960's. Topics covered were: discovery of…

Model of a tunneling current in a p-n junction based on armchair graphene nanoribbons - an Airy function approach and a transfer matrix method

International Nuclear Information System (INIS)

Suhendi, Endi; Syariati, Rifki; Noor, Fatimah A.; Khairurrijal; Kurniasih, Neny

2014-01-01

We modeled a tunneling current in a p-n junction based on armchair graphene nanoribbons (AGNRs) by using an Airy function approach (AFA) and a transfer matrix method (TMM). We used β-type AGNRs, in which its band gap energy and electron effective mass depends on its width as given by the extended Huckel theory. It was shown that the tunneling currents evaluated by employing the AFA are the same as those obtained under the TMM. Moreover, the calculated tunneling current was proportional to the voltage bias and inversely with temperature

A combined physiological and proteomic approach to reveal lactic-acid-induced alterations in Lactobacillus casei Zhang and its mutant with enhanced lactic acid tolerance.

Science.gov (United States)

Wu, Chongde; Zhang, Juan; Chen, Wei; Wang, Miao; Du, Guocheng; Chen, Jian

2012-01-01

Lactobacillus casei has traditionally been recognized as a probiotic and frequently used as an adjunct culture in fermented dairy products, where acid stress is an environmental condition commonly encountered. In the present study, we carried out a comparative physiological and proteomic study to investigate lactic-acid-induced alterations in Lactobacillus casei Zhang (WT) and its acid-resistant mutant. Analysis of the physiological data showed that the mutant exhibited 33.8% higher glucose phosphoenolpyruvate:sugar phosphotransferase system activity and lower glycolytic pH compared with the WT under acidic conditions. In addition, significant differences were detected in both cells during acid stress between intracellular physiological state, including intracellular pH, H(+)-ATPase activity, and intracellular ATP pool. Comparison of the proteomic data based on 2D-DIGE and i-TRAQ indicated that acid stress invoked a global change in both strains. The mutant protected the cells against acid damage by regulating the expression of key proteins involved in cellular metabolism, DNA replication, RNA synthesis, translation, and some chaperones. Proteome results were validated by Lactobacillus casei displaying higher intracellular aspartate and arginine levels, and the survival at pH 3.3 was improved 1.36- and 2.10-fold by the addition of 50-mM aspartate and arginine, respectively. To our knowledge, this is the first demonstration that aspartate may be involved in acid tolerance in Lactobacillus casei. Results presented here may help us understand acid resistance mechanisms and help formulate new strategies to enhance the industrial applications of this species.

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

NARCIS (Netherlands)

Adamala, K.; Anella, F.M.; Wieczorek, R.; Stano, P.; Chiarabelli, C.; Luisi, P.L.

2014-01-01

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

Acid rain information book. Draft final report

Energy Technology Data Exchange (ETDEWEB)

None

1980-12-01

Acid rain is one of the most widely publicized environmental issues of the day. The potential consequences of increasingly widespread acid rain demand that this phenomenon be carefully evaluated. Reveiw of the literature shows a rapidly growing body of knowledge, but also reveals major gaps in understanding that need to be narrowed. This document discusses major aspects of the acid rain phenomenon, points out areas of uncertainty, and summarizes current and projected research by responsible government agencies and other concerned organizations.

Approaches to chronic disease management evaluation in use in Europe: a review of current methods and performance measures.

Science.gov (United States)

Conklin, Annalijn; Nolte, Ellen; Vrijhoef, Hubertus

2013-01-01

An overview was produced of approaches currently used to evaluate chronic disease management in selected European countries. The study aims to describe the methods and metrics used in Europe as a first to help advance the methodological basis for their assessment. A common template for collection of evaluation methods and performance measures was sent to key informants in twelve European countries; responses were summarized in tables based on template evaluation categories. Extracted data were descriptively analyzed. Approaches to the evaluation of chronic disease management vary widely in objectives, designs, metrics, observation period, and data collection methods. Half of the reported studies used noncontrolled designs. The majority measure clinical process measures, patient behavior and satisfaction, cost and utilization; several also used a range of structural indicators. Effects are usually observed over 1 or 3 years on patient populations with a single, commonly prevalent, chronic disease. There is wide variation within and between European countries on approaches to evaluating chronic disease management in their objectives, designs, indicators, target audiences, and actors involved. This study is the first extensive, international overview of the area reported in the literature.

Approach to integrate current safeguards measures with additional protocol requirements at national level

International Nuclear Information System (INIS)

Ramirez, R.

2001-01-01

Peru adhered to the Additional Protocol in March 2000 which was also approved by the Congress in May 2001. After approval by law the obligations derived from this Additional Protocol will be in force after 180 days. After the signing of the Protocol an approach was designed to help better fulfill these requirements in an integrated way with the previous measures. As first stage, a review of the current state of safeguards was undertaken. Under the current agreement (an INFCIRC/153 type agreement) the reporting is less complicated and inexpensive to be carried out because these reports include only the declared nuclear material and the features of declared facilities where the nuclear material is used. No other related facility or material or activity needs to be declared. In Peru there are only two MBAs where low enriched uranium (LEU) is used and the record system includes general ledgers, inventory records and operational books. The results of national inspections and copies of reports and communications sent to the IAEA are also kept in this system. Under the agreement and subsidiary arrangements material balance reports (MBR), physical inventory listings (PIL) and inventory change reports (ICR) are prepared and submitted to the IAEA at scheduled periods. The MBR and PIL reports are sent after yearly regular inspections carried out by the IAEA. The ICR is sent just every time when an import or export of nuclear material is made. The time devoted to carry out all of these activities is not so extensive for both the State System for Accountability and Control (SSAC) and the users because of the limited nuclear activities in the country. Because of the characteristics and limited quantities of nuclear material the efforts for inspection and reporting activities are few. Another subject under review was the procedure for controlling the imports of nuclear material. Under the current agreement this subject was not a problem, as all of the radioactive and nuclear

Direct quantification of fatty acids in wet microalgal and yeast biomass via a rapid in situ fatty acid methyl ester derivatization approach.

Science.gov (United States)

Dong, Tao; Yu, Liang; Gao, Difeng; Yu, Xiaochen; Miao, Chao; Zheng, Yubin; Lian, Jieni; Li, Tingting; Chen, Shulin

2015-12-01

Accurate determination of fatty acid contents is routinely required in microalgal and yeast biofuel studies. A method of rapid in situ fatty acid methyl ester (FAME) derivatization directly from wet fresh microalgal and yeast biomass was developed in this study. This method does not require prior solvent extraction or dehydration. FAMEs were prepared with a sequential alkaline hydrolysis (15 min at 85 °C) and acidic esterification (15 min at 85 °C) process. The resulting FAMEs were extracted into n-hexane and analyzed using gas chromatography. The effects of each processing parameter (temperature, reaction time, and water content) upon the lipids quantification in the alkaline hydrolysis step were evaluated with a full factorial design. This method could tolerate water content up to 20% (v/v) in total reaction volume, which equaled up to 1.2 mL of water in biomass slurry (with 0.05-25 mg of fatty acid). There were no significant differences in FAME quantification (p>0.05) between the standard AOAC 991.39 method and the proposed wet in situ FAME preparation method. This fatty acid quantification method is applicable to fresh wet biomass of a wide range of microalgae and yeast species.

Understanding Fatty Acid Metabolism through an Active Learning Approach

Science.gov (United States)

Fardilha, M.; Schrader, M.; da Cruz e Silva, O. A. B.; da Cruz e Silva, E. F.

2010-01-01

A multi-method active learning approach (MALA) was implemented in the Medical Biochemistry teaching unit of the Biomedical Sciences degree at the University of Aveiro, using problem-based learning as the main learning approach. In this type of learning strategy, students are involved beyond the mere exercise of being taught by listening. Less…

Prevention of Ophthalmia Neonatorum Caused by Neisseria gonorrhoeae Using a Fatty Acid-Based Formulation

Directory of Open Access Journals (Sweden)

Colin P. Churchward

2017-07-01

Full Text Available Ophthalmia neonatorum, also called neonatal conjunctivitis, acquired during delivery can occur in the first 28 days of life. Commonly caused by the bacterial pathogen Neisseria gonorrhoeae, infection can lead to corneal scarring, perforation of the eye, and blindness. One approach that can be taken to prevent the disease is the use of an ophthalmic prophylaxis, which kills the bacteria on the surface of the eye shortly after birth. Current prophylaxes are based on antibiotic ointments. However, N. gonorrhoeae is resistant to many antibiotics and alternative treatments must be developed before the condition becomes untreatable. This study focused on developing a fatty acid-based prophylaxis. For this, 37 fatty acids or fatty acid derivatives were screened in vitro for fast antigonococcal activity. Seven candidates were identified as bactericidal at 1 mM. These seven were subjected to irritation testing using three separate methods: the bovine corneal opacity and permeability (BCOP test; the hen’s egg test—chorioallantoic membrane (HET-CAM; and the red blood cell (RBC lysis assay. The candidates were also tested in artificial tear fluid to determine whether they were effective in this environment. Four of the candidates remained effective. Among these, two lead candidates, monocaprin and myristoleic acid, displayed the best potential as active compounds in the development of a fatty acid-based prophylaxis for prevention of ophthalmia neonatorum.

A Large Underestimate of Formic Acid from Tropical Fires: Constraints from Space-Borne Measurements.

Science.gov (United States)

Chaliyakunnel, S; Millet, D B; Wells, K C; Cady-Pereira, K E; Shephard, M W

2016-06-07

Formic acid (HCOOH) is one of the most abundant carboxylic acids and a dominant source of atmospheric acidity. Recent work indicates a major gap in the HCOOH budget, with atmospheric concentrations much larger than expected from known sources. Here, we employ recent space-based observations from the Tropospheric Emission Spectrometer with the GEOS-Chem atmospheric model to better quantify the HCOOH source from biomass burning, and assess whether fire emissions can help close the large budget gap for this species. The space-based data reveal a severe model HCOOH underestimate most prominent over tropical burning regions, suggesting a major missing source of organic acids from fires. We develop an approach for inferring the fractional fire contribution to ambient HCOOH and find, based on measurements over Africa, that pyrogenic HCOOH:CO enhancement ratios are much higher than expected from direct emissions alone, revealing substantial secondary organic acid production in fire plumes. Current models strongly underestimate (by 10 ± 5 times) the total primary and secondary HCOOH source from African fires. If a 10-fold bias were to extend to fires in other regions, biomass burning could produce 14 Tg/a of HCOOH in the tropics or 16 Tg/a worldwide. However, even such an increase would only represent 15-20% of the total required HCOOH source, implying the existence of other larger missing sources.

Optical nano-biosensing interface via nucleic acid amplification strategy: construction and application.

Science.gov (United States)

Zhou, Hong; Liu, Jing; Xu, Jing-Juan; Zhang, Shu-Sheng; Chen, Hong-Yuan

2018-03-21

Modern optical detection technology plays a critical role in current clinical detection due to its high sensitivity and accuracy. However, higher requirements such as extremely high detection sensitivity have been put forward due to the clinical needs for the early finding and diagnosing of malignant tumors which are significant for tumor therapy. The technology of isothermal amplification with nucleic acids opens up avenues for meeting this requirement. Recent reports have shown that a nucleic acid amplification-assisted modern optical sensing interface has achieved satisfactory sensitivity and accuracy, high speed and specificity. Compared with isothermal amplification technology designed to work completely in a solution system, solid biosensing interfaces demonstrated better performances in stability and sensitivity due to their ease of separation from the reaction mixture and the better signal transduction on these optical nano-biosensing interfaces. Also the flexibility and designability during the construction of these nano-biosensing interfaces provided a promising research topic for the ultrasensitive detection of cancer diseases. In this review, we describe the construction of the burgeoning number of optical nano-biosensing interfaces assisted by a nucleic acid amplification strategy, and provide insightful views on: (1) approaches to the smart fabrication of an optical nano-biosensing interface, (2) biosensing mechanisms via the nucleic acid amplification method, (3) the newest strategies and future perspectives.

Ultra-sensitive EUV resists based on acid-catalyzed polymer backbone breaking

Science.gov (United States)

Manouras, Theodoros; Kazazis, Dimitrios; Koufakis, Eleftherios; Ekinci, Yasin; Vamvakaki, Maria; Argitis, Panagiotis

2018-03-01

The main target of the current work was to develop new sensitive polymeric materials for lithographic applications, focusing in particular to EUV lithography, the main chain of which is cleaved under the influence of photogenerated acid. Resist materials based on the cleavage of polymer main chain are in principle capable to create very small structures, to the dimensions of the monomers that they consist of. Nevertheless, in the case of the commonly used nonchemically amplified materials of this type issues like sensitivity and poor etch resistance limit their areas of application, whereas inadequate etch resistance and non- satisfactory process reliability are the usual problems encountered in acid catalysed materials based on main chain scission. In our material design the acid catalyzed chain cleavable polymers contain very sensitive moieties in their backbone while they remain intact in alkaline ambient. These newly synthesized polymers bear in addition suitable functional groups for the achievement of desirable lithographic characteristics (thermal stability, acceptable glass transition temperature, etch resistance, proper dissolution behavior, adhesion to the substrate). Our approach for achieving acceptable etch resistance, a main drawback in other main chain cleavable resists, is based on the introduction of polyaromatic hydrocarbons in the polymeric backbone, whereas the incorporation of an inorganic component further enhances the etch resistance. Single component systems can also be designed following the proposed approach by the incorporation of suitable PAGs and base quencher molecules in the main chain. Resist formulations based on a random copolymer designed according to the described rules evaluated in EUV exhibit ultrahigh sensitivity, capability for high resolution patterning and overall processing characteristics that make them strong candidates for industrial use upon further optimization.

Reconstituted injectable hyaluronic acid: expanded applications in facial aesthetics and additional thoughts on the mechanism of action in cosmetic medicine.

Science.gov (United States)

Fagien, Steven; Cassuto, Daniel

2012-07-01

As we currently have a better understanding of the components of facial aging, injectable filling agents have a larger role in nonsurgical facial rejuvenation. Many products are now available worldwide as options for treating the spectrum of indications that include particular agents used for the treatment of various facial rhytides and in larger quantities for regional or panfacial volumization. The latter indication has been most popularly treated with a host of agents classified as hyaluronans or injectable hyaluronic acid gels. The former had been traditionally and more successfully treated with injectable collagen or dermal matrix agents. Attempts to confuse these generalized approaches have often led to unsatisfactory results. With the precipitous disappearance of the availability of most injectable collagen substances, other methods of treating finer facial rhytides have been explored. Of the many options available for the treatment of facial fine lines, the authors describe a novel technique of formulating reduced concentrations of existing hyaluronic acid gels by variable dilution/reconstitution. Over 350 of the authors' collective patients have been treated with this approach. The results have been highly satisfactory, with greater persistence, and have challenged traditional concepts of mechanism of action and biodegradation and suggest alternative options in formulations of currently available products. Reconstituted injectable hyaluronic acid is a highly effective and viable alternative for the aesthetic treatment of facial fine lines and other components of aging. Observations, treatment guidelines, and a rationale for this novel use and concepts to explain these finding are contained in this article.

Citric Acid Passivation of Stainless Steel

Science.gov (United States)

Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

2009-01-01

Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

Chiral separation of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography with biphasic recognition

Science.gov (United States)

Tong, Shengqiang

2010-01-01

This work concentrates on a novel chiral separation technology named biphasic recognition applied to resolution of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography (HSCCC). The biphasic chiral recognition HSCCC was performed by adding lipophilic (−)-2-ethylhexyl tartrate in the organic stationary phase and hydrophilic hydroxypropyl-β-cyclodextrin in the aqueous mobile phase, which preferentially recognized the (−)-enantiomer and (+)-enantiomer, respectively. The two-phase solvent system composed of n-hexane-methyl tert-butyl ether-water (9:1:10, v/v/v) with the above chiral selectors was selected according to the partition coefficient and separation factor of the target enantiomers. Various parameters involved in the chiral separation were investigated, namely the types of the chiral selector (CS); the concentration of each chiral selector; pH of the mobile phase; and the separation temperature. The mechanism involved in this biphasic recognition chiral separation by HSCCC was discussed. Langmuirian isotherm was employed to estimate the loading limits for each chiral selector. The overall experimental results show that the HSCCC separation of enantiomer based on biphasic recognition is much more efficient than the traditional monophasic recognition chiral separation, since it utilizes the cooperation of both lipophilic and hydrophilic chiral selectors. PMID:20303497

Electrochemical Sensor for Determination of Ascorbic Acid Using a 2-Chlorobenzoyl Ferrocene/Carbon Nanotube Paste Electrode

Directory of Open Access Journals (Sweden)

Sayed Zia Mohammadi

2016-12-01

Full Text Available A chemically modified carbon paste electrode with 2-chlorobenzoyl ferrocene (2CBF and carbon nanotube (2CBFCNPE was employed to study the electrocatalytic oxidation of ascorbic acid in aqueous solution using cyclic voltammetry, square wave voltammetry and chronoamperometry. The diffusion coefficient (D = 1.42 × 10-6 cm2 s-1, and the kinetic parameter such as the catalytic rate constant (k = 3.7 × 10 3 M-1 s-1 of ascorbic acid oxidation at the surface of 2CBFCNPE were determined using electrochemical approaches. It has been found that under an optimum condition (pH 4.0, the oxidation of ascorbic acid at the surface of such an electrode occurs at a potential about 85 mV less positive than that of an unmodified carbon paste electrode. Applying square wave voltammetry, in phosphate buffer solution (PBS of pH 4.0, the oxidation current increases linearly with two concentration intervals of ascorbic acid, one is 1.0 × 10-7-2.5 × 10-6 M and the other is 2.5 × 10-6-7.0 × 10-5 M. Detection limit (3δ was obtained 64.0 nM. This method was also examined for determination of ascorbic acid in some real samples.

A New Approach on Output Current Calculation for Thimble-type Ionization Chamber with Variation of Gamma-ray Irradiation Angle

International Nuclear Information System (INIS)

Kim, Jae Cheon; Kim, Soon Young; Kim, Yong Kyun; Kim, Jong Kyung

2006-01-01

The output current of an ionization chamber is directly connected with the size of the active volume and ion-pair distribution in air volume. Their accurate assessments are significantly important in order to analyze the design characteristics of an ionization chamber and interpret the measurements with it. It has been generally assumed that ion-pairs are generated uniformly in air volume for simplicity although they are not uniformly distributed due to various source and geometry conditions. Ion-pair distribution is mainly dependent on the irradiation source conditions, while active volume is deeply related to the ionization chamber design. Therefore, such assumption should be examined if the ion-pair distribution affects real output current of the active volume defined by electric field. A new analytical approach considering both electric field and ion-pair nonuniformity has been proposed to analyze accurately the design characteristics of an ionization chamber and interpretation of measurements with it. The angular dependence analysis was carried out to validate the new concept for calculation of output current

Exchange processes at geosphere-biosphere interface. Current SKB approach and example of coupled hydrological-ecological approach

Energy Technology Data Exchange (ETDEWEB)

Woerman, Anders [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Biometry and Technology

2003-09-01

The design of the repository for final disposal of spent nuclear fuel proposed by SKB is based on a multi-barrier system, in which the geosphere and biosphere are the utmost barrier surrounding the engineer barriers. This report briefly reviews the current approach taken by SKB to account for hydrological and ecological processes at the geosphere-biosphere interface (GBI) and their future plans in this area. A simple analysis was performed to shift the focus of performance assessment involving geosphere-biosphere interface modelling from the very simplistic assumption that the quaternary sediments are bypassed to one in which a more detailed model for sub-surface flows is included. This study indicated that, for many assumed ecosystem descriptions, the presence of the GBI leads to lower maximum doses to individual humans compared to a case when the GBI is neglected. This effect is due to the additional 'barrier' offered by the GBI. The main exposure pathways were assumed to occur through the food web. However, particularly the leakage on land through the stream-network and lakes can lead to higher doses due to ecosystem interaction with arable land. A scenario that gives particularly long duration of doses occurs due to land rise and with the transformation of the former bay and lake bed sediments into agricultural land. This effect is due to the significant retention or accumulation in aquatic sediment, which causes high activities to build up with time. Particularly, in combination with changing conditions in climate, humans life-style or geographic conditions (land rise, deforestation,etc.) doses to individual humans can be large.

Biotechnological Production of Lactic Acid and Its Recent Applications

Directory of Open Access Journals (Sweden)

Young-Jung Wee

2006-01-01

Full Text Available Lactic acid is widely used in the food, cosmetic, pharmaceutical, and chemical industries and has received increased attention for use as a monomer for the production of biodegradable poly(lactic acid. It can be produced by either biotechnological fermentation or chemical synthesis, but the former route has received considerable interest recently, due to environmental concerns and the limited nature of petrochemical feedstocks. There have been various attempts to produce lactic acid efficiently from inexpensive raw materials. We present a review of lactic acid-producing microorganisms, raw materials for lactic acid production, fermentation approaches for lactic acid production, and various applications of lactic acid, with a particular focus on recent investigations. In addition, the future potentials and economic impacts of lactic acid are discussed.

Comparative sequence analysis of acid sensitive/resistance proteins in Escherichia coli and Shigella flexneri

Science.gov (United States)

Manikandan, Selvaraj; Balaji, Seetharaaman; Kumar, Anil; Kumar, Rita

2007-01-01

The molecular basis for the survival of bacteria under extreme conditions in which growth is inhibited is a question of great current interest. A preliminary study was carried out to determine residue pattern conservation among the antiporters of enteric bacteria, responsible for extreme acid sensitivity especially in Escherichia coli and Shigella flexneri. Here we found the molecular evidence that proved the relationship between E. coli and S. flexneri. Multiple sequence alignment of the gadC coded acid sensitive antiporter showed many conserved residue patterns at regular intervals at the N-terminal region. It was observed that as the alignment approaches towards the C-terminal, the number of conserved residues decreases, indicating that the N-terminal region of this protein has much active role when compared to the carboxyl terminal. The motif, FHLVFFLLLGG, is well conserved within the entire gadC coded protein at the amino terminal. The motif is also partially conserved among other antiporters (which are not coded by gadC) but involved in acid sensitive/resistance mechanism. Phylogenetic cluster analysis proves the relationship of Escherichia coli and Shigella flexneri. The gadC coded proteins are converged as a clade and diverged from other antiporters belongs to the amino acid-polyamine-organocation (APC) superfamily. PMID:21670792

[Folic acid in physiology and pathology].

Science.gov (United States)

Czeczot, Hanna

2008-08-13

This paper presents current knowledge of the biological functions of folic acid, the effects of its deficiency in the organism, as well as the possibilities of its therapeutic use. Folic acid (folate, B9) is a vitamin of special importance in normal cellular functions. Tetrahydrofolate (TH4-folate) is the biologically active form of folic acid. The main role of folic acid in biochemistry is the single-carbon transfer reaction (e.g. transfer of a methyl, methylene, or formyl group). Folic acid is involved in the transformation of certain amino acids as well as in the synthesis of purines and dTMP (2'-deoxythymidine-5'-phosphate) needed for the synthesis of nucleic acid (DNA), required by all rapidly growing cells. In humans, folate deficiency results in serious pathologies, the most important of which are neural tube defects, megablastic anemia, acceleration of the arteriosclerotic process, changes in the central nervous system, and the development of certain types of cancer. To increase the intake of folic acid, preventive actions include dietary education, the main objectives of which are to increase the intake of natural folate in the daily diet, add folic acid to selected dietary products (e.g. fl our, pasta, rice), and encourage supplementation with folic acid-containing pharmaceuticals.

The current approach to human error and blame in the NHS.

Science.gov (United States)

Ottewill, Melanie

There is a large body of research to suggest that serious errors are widespread throughout medicine. The traditional response to these adverse events has been to adopt a 'person approach' - blaming the individual seen as 'responsible'. The culture of medicine is highly complicit in this response. Such an approach results in enormous personal costs to the individuals concerned and does little to address the root causes of errors and thus prevent their recurrence. Other industries, such as aviation, where safety is a paramount concern and which have similar structures to the medical profession, have, over the past decade or so, adopted a 'systems' approach to error, recognizing that human error is ubiquitous and inevitable and that systems need to be developed with this in mind. This approach has been highly successful, but has necessitated, first and foremost, a cultural shift. It is in the best interests of patients, and medical professionals alike, that such a shift is embraced in the NHS.

Current diagnostic approach of bone tumors in childhood

International Nuclear Information System (INIS)

Torre, Marcia Barbosa; Scatigno Neto, Andre

1995-01-01

The authors analyze the magnetic resonance imaging (MRI) as the imaging modality of choice for evaluation of patients with bone tumors or soft tissue tumors. The advent of such a sensitive imaging modality is fortuitous and coincides with a recent change in the therapeutic approach to primary bone tumors. MRI is extremely valuable in monitoring the tumor response to the initial chemotherapy and is accurate defining the margins of tumor, facilitating planning of limb salvage surgical procedures. (author). 5 refs., 8 figs

High Concentrations of Tranexamic Acid Inhibit Ionotropic Glutamate Receptors.

Science.gov (United States)

Lecker, Irene; Wang, Dian-Shi; Kaneshwaran, Kirusanthy; Mazer, C David; Orser, Beverley A

2017-07-01

The antifibrinolytic drug tranexamic acid is structurally similar to the amino acid glycine and may cause seizures and myoclonus by acting as a competitive antagonist of glycine receptors. Glycine is an obligatory co-agonist of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors. Thus, it is plausible that tranexamic acid inhibits NMDA receptors by acting as a competitive antagonist at the glycine binding site. The aim of this study was to determine whether tranexamic acid inhibits NMDA receptors, as well as α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and kainate subtypes of ionotropic glutamate receptors. Tranexamic acid modulation of NMDA, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, and kainate receptors was studied using whole cell voltage-clamp recordings of current from cultured mouse hippocampal neurons. Tranexamic acid rapidly and reversibly inhibited NMDA receptors (half maximal inhibitory concentration = 241 ± 45 mM, mean ± SD; 95% CI, 200 to 281; n = 5) and shifted the glycine concentration-response curve for NMDA-evoked current to the right. Tranexamic acid also inhibited α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (half maximal inhibitory concentration = 231 ± 91 mM; 95% CI, 148 to 314; n = 5 to 6) and kainate receptors (half maximal inhibitory concentration = 90 ± 24 mM; 95% CI, 68 to 112; n = 5). Tranexamic acid inhibits NMDA receptors likely by reducing the binding of the co-agonist glycine and also inhibits α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and kainate receptors. Receptor blockade occurs at high millimolar concentrations of tranexamic acid, similar to the concentrations that occur after topical application to peripheral tissues. Glutamate receptors in tissues including bone, heart, and nerves play various physiologic roles, and tranexamic acid inhibition of these receptors may contribute to adverse drug effects.

Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

Energy Technology Data Exchange (ETDEWEB)

Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

2015-01-07

Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe{sup 3+} ion sensing by fluorescence quenching is developed. • The method for Fe{sup 3+} sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe{sup 3+}) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe{sup 3+} permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe{sup 3+} in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%.

Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor