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Sample records for acid change converts

  1. A single amino acid change converts the sugar sensor SGLT3 into a sugar transporter.

    Laura Bianchi

    Full Text Available BACKGROUND: Sodium-glucose cotransporter proteins (SGLT belong to the SLC5A family, characterized by the cotransport of Na(+ with solute. SGLT1 is responsible for intestinal glucose absorption. Until recently the only role described for SGLT proteins was to transport sugar with Na(+. However, human SGLT3 (hSGLT3 does not transport sugar but causes depolarization of the plasma membrane when expressed in Xenopus oocytes. For this reason SGLT3 was suggested to be a sugar sensor rather than a transporter. Despite 70% amino acid identity between hSGLT3 and hSGLT1, their sugar transport, apparent sugar affinities, and sugar specificity differ greatly. Residue 457 is important for the function of SGLT1 and mutation at this position in hSGLT1 causes glucose-galactose malabsorption. Moreover, the crystal structure of vibrio SGLT reveals that the residue corresponding to 457 interacts directly with the sugar molecule. We thus wondered if this residue could account for some of the functional differences between SGLT1 and SGLT3. METHODOLOGY/PRINCIPAL FINDINGS: We mutated the glutamate at position 457 in hSGLT3 to glutamine, the amino acid present in all SGLT1 proteins, and characterized the mutant. Surprisingly, we found that E457Q-hSGLT3 transported sugar, had the same stoichiometry as SGLT1, and that the sugar specificity and apparent affinities for most sugars were similar to hSGLT1. We also show that SGLT3 functions as a sugar sensor in a living organism. We expressed hSGLT3 and E457Q-hSGLT3 in C. elegans sensory neurons and found that animals sensed glucose in an hSGLT3-dependent manner. CONCLUSIONS/SIGNIFICANCE: In summary, we demonstrate that hSGLT3 functions as a sugar sensor in vivo and that mutating a single amino acid converts this sugar sensor into a sugar transporter similar to SGLT1.

  2. Processes for converting lignocellulosics to reduced acid pyrolysis oil

    Kocal, Joseph Anthony; Brandvold, Timothy A

    2015-01-06

    Processes for producing reduced acid lignocellulosic-derived pyrolysis oil are provided. In a process, lignocellulosic material is fed to a heating zone. A basic solid catalyst is delivered to the heating zone. The lignocellulosic material is pyrolyzed in the presence of the basic solid catalyst in the heating zone to create pyrolysis gases. The oxygen in the pyrolysis gases is catalytically converted to separable species in the heating zone. The pyrolysis gases are removed from the heating zone and are liquefied to form the reduced acid lignocellulosic-derived pyrolysis oil.

  3. Changes of Plasma Angiotensin-Converting Enzyme Activity during Hemodialysis *

    Koo, Wan Suh; Lee, Yong Joon; Kim, Hye Su; Kim, Suk Young; Choi, Euy Jin; Chang, Yoon Sik; Yoon, Young Suk; Bang, Byung Kee

    1987-01-01

    Plasma angiotensin-converting enzyme activity was measured by spectrophotometer in normal subjects and in patients with end stage renal failure, serially during a routine hemodialysis. Patients on maintenance hemodialysis tended to be associated with elevated plasma angiotensin-converting enzyme activity versus normal subjects. Plasma angiotensin-converting enzyme activity was significantly elevated in patients with chronic renal failure after 5 hours of hemodialysis(p

  4. Effects of Converter Slag on some Chemical Characteristics of Acid Soils

    H. Shariatmadari

    2005-01-01

    Full Text Available Lintz-Donawitz (LD converter slag, a by-product of the iron and steel-making industry is produced in large quantities in Isfahan, Iran. The slag contains 52.8 and 2.2% (w/w CaO and MgO, respectively. To determine the influence of LD slag on the chemical characteristics of three acid soils from Gilan, an incubation study was conducted. The soil samples were collected from 0-30 cm of rice and tobacco fields and a tea garden. Treatments were 0, 0.5, 1, 2, 4, 8 and 16 % (w/w of converter slag/kg soil. The slag was thoroughly mixed with 500g soil in plastic pots. Soil moisture content was adjusted to near field capacity and changes in pH, EC and AB-DTPA-extractable Fe, Mn, Zn, P and K were determined at 1, 10, 30 and 60 days. Results showed that soil pH increased with increasing slag rates. Slag increased AB-DTPA-extractable P and Mn, the magnitude increase depend on the amount of slag applied. However, the effect of slag on AB-DTPA-extractable Fe depended on initial pH, initially decreasing at the pH range of 7.4 - 8.5 and then increasing at higher pH levels. Slag decreased AB-DTPA-extractable K especially in highly acid soil. In the present study, soil pH and AB-DTPA-extractable Fe decreased with time, though the effect of incubation time on pH was not significant. The effect of incubation time on AB-DTPA extractable Mn and P was different. Time effect on EC and AB-DTPA-extractable K was not significant. In general, soil chemical characteristics were more affected by slag rates than by incubation time. In conclusion, it seems that converter slag is a suitable amendment for acid soils. It is suggested that the effect of LD converter slag on plant growth and chemical characteristics of acid soils be studied under field conditions.

  5. Feasibility of converting lactic acid to ethanol in food waste fermentation by immobilized lactate oxidase

    Highlights: • Residue lactic acid in food waste could be converted to pyruvic acid. • Calcium alginate immobilized the lactate oxidase with high pH and thermal stability. • Immobilized enzyme could convert 70% lactic acid to pyruvic acid. • Ethanol yield could be increased by 20% with lactate oxidase added. - Abstract: Adoption of lactic acid bacteria (LAB) into ethanol fermentation from food waste can replace the sterilization process. However, LAB inoculation will convert part of the substrate into lactic acid (LA), not ethanol. This study adopted lactate oxidase to convert the produced LA to pyruvate, and then ethanol fermentation was carried out. The immobilization enzyme was utilized, and corresponding optimum conditions were determined. Results showed that calcium alginate could successfully immobilize the enzyme and improve pH and thermal stability. The optimum pH and temperature were 6.2 and 55 °C, respectively. The utilization of immobilized enzyme with catalytic time of 5 h could convert 70% LA to pyruvate, and the addition of enzyme increased the ethanol yield by 20% more than that of the control. The process could be applied in food waste storage and can help in reducing carbon source consumption

  6. Density assumptions for converting geodetic glacier volume change to mass change

    M. Huss

    2013-05-01

    Full Text Available The geodetic method is widely used for assessing changes in the mass balance of mountain glaciers. However, comparison of repeated digital elevation models only provides a glacier volume change that must be converted to a change in mass using a density assumption or model. This study investigates the use of a constant factor for the volume-to-mass conversion based on a firn compaction model applied to simplified glacier geometries with idealized climate forcing, and two glaciers with long-term mass balance series. It is shown that the "density" of geodetic volume change is not a constant factor and is systematically smaller than ice density in most cases. This is explained by the accretion/removal of low-density firn layers, and changes in the firn density profile with positive/negative mass balance. Assuming a value of 850 ± 60 kg m−3 to convert volume change to mass change is appropriate for a wide range of conditions. For short time intervals (≤3 yr, periods with limited volume change, and/or changing mass balance gradients, the conversion factor can however vary from 0–2000 kg m−3 and beyond, which requires caution when interpreting glacier mass changes based on geodetic surveys.

  7. Molybdenum-containing acidic catalysts to convert cellulosic biomass to glycolic acid

    Han, Yu

    2014-09-30

    Embodiments of the present invention include methods and compositions related to catabolic conversion of cellulosic biomass to glycolic acid using molybdenum-containing acidic catalysts. The invention includes the use of heteropoly and isopoly acids and salts as the molybdenum-containing multi-functional catalysts for biomass conversion. In embodiments of the invention, the reactions employ successive hydrolysis, retro-aldol fragmentation, and selective oxidation in a noble metal-free system.

  8. Anhydrous trifluoroacetic acid pretreatment converts insoluble polyglutamine peptides to soluble monomers

    Gunasekhar Burra

    2015-12-01

    Full Text Available The data provided in this article are related to the research article entitled “Unaided trifluoroacetic acid pretreatment solubilizes polyglutamine (polyGln peptides and retains their biophysical properties of aggregation” by Burra and Thakur (in press [1]. This research article reports data from size exclusion chromatography (SEC, reversed phase-high performance liquid chromatography (RP-HPLC and mass spectrometry (MS assays. This data show that trifluoroacetic acid (TFA has the ability to convert insoluble polyGln peptides to soluble monomers. The data also clarify the possibility of trifluoroacetylation modification caused due to TFA. We hope the data presented here will enhance the understanding of polyGln disaggregation and solubilization. For more insightful and useful discussions, see the research article published in Analytical Biochemistry: Methods in the Biological Sciences (Burra and Thakur, in press [1].

  9. Inability of murine peritoneal macrophages to convert linoleic acid into arachidonic acid. Evidence of chain elongation

    Various murine macrophage populations synthesize and secrete large amounts of arachidonic acid (20:4n-6) derived eicosanoids (cyclo-oxygenase and lipoxygenase products). These metabolites are known to possess a wide variety of functions with regard to the initiation and regulation of inflammation and tumorigenesis. Because the dietary intake of 20:4n-6 is usually low, tissues are largely dependent upon dietary linoleic acid (18:2n-6) as an initial unsaturated precursor for the biosynthesis of 20:4n-6. The purpose of these experiments was to determine whether resident or responsive murine macrophages possess desaturase and elongase activities capable of in vitro conversion of 18:2n-6 into 20:4n-6. Peritoneal exudate macrophages were purified by adherence and incubated in serum-free medium containing fatty acid-free BSA with [1-14C] 18:2n-6. Approximately 90 to 98% of the [14C]18:2n-6 at 4 and 16 h was recovered in phosphatidylcholine and phosphatidylethanolamine. The metabolism of [14C]18:2n-6 was determined after transesterification and separation of the 14C-fatty acid methyl esters by argentation TLC, reverse phase HPLC, and electron impact gas chromatography/mass spectrometry. Resident and responsive macrophages lacked the capacity to transform [14C]18:2n-6 into 20:4n-6. In addition, prelabeled macrophages incubated with soluble, calcium ionophore A23187 or phorbol myristate, or particulate, zymosan, membrane perturbing agents also lacked delta 6 desaturase activity. All macrophages tested were capable of elongating [14C]18:2n-6 into [14C]20:2n-6. These observations suggest that 20:4n-6, present in macrophage phospholipids, is biosynthesized elsewhere and transported to the macrophage for esterification into the phospholipids. In addition, these findings demonstrate that elongase activity is present in both the resident and responsive peritoneal macrophage

  10. Characterization of two Streptomyces enzymes that convert ferulic acid to vanillin.

    Wenwen Yang

    Full Text Available Production of flavors from natural substrates by microbial transformation has become a growing and expanding field of study over the past decades. Vanillin, a major component of vanilla flavor, is a principal flavoring compound used worldwide. Streptomyces sp. strain V-1 is known to be one of the most promising microbial producers of natural vanillin from ferulic acid. Although identification of the microbial genes involved in the biotransformation of ferulic acid to vanillin has been previously reported, purification and detailed characterization of the corresponding enzymes with important functions have rarely been studied. In this study, we isolated and identified 2 critical genes, fcs and ech, encoding feruloyl-CoA synthetase and enoyl-CoA hydratase/aldolase, respectively, which are involved in the vanillin production from ferulic acid. Both genes were heterologously expressed in Escherichia coli, and the resting cell reactions for converting ferulic acid to vanillin were performed. The corresponding crucial enzymes, Fcs and Ech, were purified for the first time and the enzymatic activity of each purified protein was studied. Furthermore, Fcs was comprehensively characterized, at an optimal pH of 7.0 and temperature of 30°C. Kinetic constants for Fcs revealed the apparent Km, kcat, and Vmax values to be 0.35 mM, 67.7 s(-1, and 78.2 U mg(-1, respectively. The catalytic efficiency (kcat/Km value of Fcs was 193.4 mM(-1 s(-1 for ferulic acid. The characterization of Fcs and Ech may be helpful for further research in the field of enzymatic engineering and metabolic regulation.

  11. Lactic acid bacteria convert glucosinolates to nitriles efficiently yet differently from enterobacteriaceae.

    Mullaney, Jane A; Kelly, William J; McGhie, Tony K; Ansell, Juliet; Heyes, Julian A

    2013-03-27

    Glucosinolates from the genus Brassica can be converted into bioactive compounds known to induce phase II enzymes, which may decrease the risk of cancers. Conversion via hydrolysis is usually by the brassica enzyme myrosinase, which can be inactivated by cooking or storage. We examined the potential of three beneficial bacteria, Lactobacillus plantarum KW30, Lactococcus lactis subsp. lactis KF147, and Escherichia coli Nissle 1917, and known myrosinase-producer Enterobacter cloacae to catalyze the conversion of glucosinolates in broccoli extract. Enterobacteriaceae consumed on average 65% glucoiberin and 78% glucoraphanin, transforming them into glucoiberverin and glucoerucin, respectively, and small amounts of iberverin nitrile and erucin nitrile. The lactic acid bacteria did not accumulate reduced glucosinolates, consuming all at 30-33% and transforming these into iberverin nitrile, erucin nitrile, sulforaphane nitrile, and further unidentified metabolites. Adding beneficial bacteria to a glucosinolate-rich diet may increase glucosinolate transformation, thereby increasing host exposure to bioactives. PMID:23461529

  12. Identification of deoxyribonucleic acid restriction fragments of beta-converting corynebacteriophages that carry the gene for diphtheria toxin.

    Buck, G A; Groman, N B

    1981-01-01

    Deoxyribonucleic acid fragments bearing the gene for diphtheria toxin have been identified in restriction enzyme digests of deoxyribonucleic acids from beta-converting and gamma-nonconverting corynebacteriophages. A combination of physical and genetic evidence has established that the Bam HI band C fragment of beta phage deoxyribonucleic acid, which carries the specific phage attachment site (Buck and Groman, J. Bacteriol. 148:131-142, 1981), also carries most, and probably all, of the gene f...

  13. CLIMATE CHANGE ADAPTATION IN ACID SULFATE LANDSCAPES

    Chuxia Lin

    2012-01-01

    Full Text Available Oxidation of sulfide minerals produces sulfuric acid and consequently creates Acid Sulfate Landscapes (ASLs, which represent one of the most degraded types of land-surface environments. Although acid sulfate-producing weathering is a naturally occurring process, it is markedly facilitated by human intervention. Mining is by far the dominant anthropogenic cause for the creation of inland acid sulfate footprints while land reclamation in coastal lowlands is the driver for the formation of coastal ASLs. The projected climate change highlights the possibility of an increase in the frequency and severity of extreme weather events such as droughts and heavy rains, which is likely to accelerate the acid generation in some circumstances and increase the frequency and magnitude of acid discharge. Sea level rise as a result of global warming will cause additional problems with the coastal ASLs. This is a review article. The following aspects are covered: (a the overriding biogeochemical processes leading to acid sulfate-producing weathering, (b a brief introduction to the inland acid sulfate landscapes, (c a brief introduction to the coastal acid sulfate landscapes, (d the likely impacts of climate change on ASLs and (e the possible measures to combat climate change-induced environmental degradation in the identified key acid sulfate footprints. The projected climate change is like to significantly affect the acid sulfate landscapes in different ways. Appropriate management strategies and cost-effective technologies need to be developed in order to minimize the climate change-induced ecological degradation.

  14. Process of converting starch to glucose and glucose to lactic acid

    Tsai, TenLin; Sanville, C.Y.; Coleman, R.D.; Schertz, W.W.

    1990-01-01

    This document describes a method for converting starch into lactic acid of sufficient purity for use as a substrate for biodegradable plastics. The process is designed to work on industrial food waste streams such as potato wastes or cheese whey permeate. For potato waste, {alpha}-amylase and calcium chloride are added to the starch containing waste and incubated at a pH of 4--7, a temperature of 90--130{degree}C, and a pressure above 15 psi for not less than 15 minutes. At this point, glucoamylase is added and the mixture is incubated at a temperature of 50--70{degree}C and a pH below 6.5 for 4 hours. This results in the conversion of more than 90% of the starch into glucose, which is substantially free of microbial contamination. The hydrolysate is filtered, and introduced with additional nutrients to a fermentor containing a lactose producing microorganism to form a fermentation broth. This results in the fermentation of glucose to lactose, which is filtered and subjected to electrodialysis for purification. Conversion of glucose to lactic acid or lactate occurs with an efficiency of over 95%. 1 fig. (MHB)

  15. Lactic acid bacteria: inhibition of angiotensin converting enzyme in vitro and in vivo

    Fuglsang, Anders; Rattray, Fergal; Nilsson, Dan;

    2003-01-01

    A total of 26 strains of wild-type lactic acid bacteria, mainly belonging to Lactococcus lactis and Lactobacillus helveticus , were assayed in vitro for their ability to produce a milk fermentate with inhibitory activity towards angiotensin converting enzyme (ACE). It was clear that the test...

  16. Intrarenal Distributions and Changes of Angiotensin-Converting Enzyme and Angiotensin-Converting Enzyme 2 in Feline and Canine Chronic Kidney Disease

    MITANI, Sawane; Yabuki, Akira; Sawa, Mariko; Chang, Hye-Sook; YAMATO, Osamu

    2013-01-01

    ABSTRACT Angiotensin-converting enzyme (ACE) is a key enzyme in the renin-angiotensin system (RAS). ACE2 is a newly identified member of the RAS. The present immunohistochemical study focused on changes in intrarenal ACE and ACE2 immunoreactivity in feline and canine chronic kidney disease (CKD). ACE immunoreactivity was predominantly observed in the brush border of the proximal tubules in dogs and cats. ACE immunoreactivity was lower in CKD kidneys than in normal kidneys, and quantitative an...

  17. Intrarenal distributions and changes of Angiotensin-converting enzyme and Angiotensin-converting enzyme 2 in feline and canine chronic kidney disease.

    Mitani, Sawane; Yabuki, Akira; Sawa, Mariko; Chang, Hye-Sook; Yamato, Osamu

    2014-01-01

    Angiotensin-converting enzyme (ACE) is a key enzyme in the renin-angiotensin system (RAS). ACE2 is a newly identified member of the RAS. The present immunohistochemical study focused on changes in intrarenal ACE and ACE2 immunoreactivity in feline and canine chronic kidney disease (CKD). ACE immunoreactivity was predominantly observed in the brush border of the proximal tubules in dogs and cats. ACE immunoreactivity was lower in CKD kidneys than in normal kidneys, and quantitative analysis demonstrated negative correlations between ACE and renal tissue damage in dogs. ACE2 immunoreactivity was also detected in the proximal tubules; it increased or decreased with CKD in dogs, depending on the renal region assessed. The changes in ACE and ACE2 in CKD were associated with the plasma creatinine concentration in dogs. Findings from dogs with glomerulonephritis were similar to those from dogs with non-glomerulonephritis. The present study suggests that changes in the intrarenal expression of ACE and ACE2 contribute to the pathological mechanisms of canine CKD, but not to the mechanisms of feline CKD. PMID:24004970

  18. Characterization of Two Streptomyces Enzymes That Convert Ferulic Acid to Vanillin

    Wenwen Yang; Hongzhi Tang; Jun Ni; Qiulin Wu; Dongliang Hua; Fei Tao; Ping Xu

    2013-01-01

    Production of flavors from natural substrates by microbial transformation has become a growing and expanding field of study over the past decades. Vanillin, a major component of vanilla flavor, is a principal flavoring compound used worldwide. Streptomyces sp. strain V-1 is known to be one of the most promising microbial producers of natural vanillin from ferulic acid. Although identification of the microbial genes involved in the biotransformation of ferulic acid to vanillin has been previou...

  19. Renal uptake of dimercaptosuccinic acid and glomerular filtration rate in chronic nephropathy at angiotensin converting enzyme inhibition

    Kamper, A L; Thomsen, H S; Nielsen, S L; Strandgaard, S

    1990-01-01

    function. Scintigrams of the kidneys showed an unaltered distribution of DMSA during treatment. GFR estimated by 51Cr-EDTA plasma clearance fell by 14% (P less than 0.01), but renal uptake of 99mTc-DMSA increased by 10% (P less than 0.01). It is concluded that DMSA in chronic renal failure is mainly taken......Glomerular filtration rate (GFR) and renal uptake of dimercaptosuccinic acid (DMSA) were measured in 31 patients with progressive chronic nephropathy before and immediately after the start of treatment with angiotensin converting enzyme (ACE) inhibitor in order to control adverse effects on kidney...... up by the tubular cells from the peritubular capillaries since the uptake was unaffected by the acute decrease in GFR....

  20. Diversity of Lactobacillus reuteri Strains in Converting Glycerol into 3-Hydroxypropionic Acid.

    Burgé, G; Saulou-Bérion, C; Moussa, M; Pollet, B; Flourat, A; Allais, F; Athès, V; Spinnler, H E

    2015-10-01

    The present study aims at comparing the performances of three Lactobacillus reuteri strains (DSM 20016, DSM 17938, and ATCC 53608) in producing 3-hydroxypropionic acid (3-HP) from glycerol and at exploring inhibition phenomena during this bioconversion. Differences were highlighted between the three strains in terms of 3-HP production yield, kinetics of substrate consumption, and metabolite production. With a maximal productivity in non-optimal conditions (free pH) around 2 g.L(-1).h(-1) of 3-HP and 4 g.L(-1).h(-1) of 3-hydroxypropionaldehyde (3-HPA) depending on the strain, this study confirmed the potential of L. reuteri for the biotechnological production of 3-HP. Moreover, the molar ratios of 3-HP to 1,3-propanediol (1,3-PDO) obtained for the three strains (comprised between 1.25 and 1.65) showed systematically a higher 3-HP production. From these results, the DSM 17938 strain appeared to be the most promising strain. The impact of glycerol bioconversion on the bacteria's physiological state (a decrease of around 40 % in DSM 17938 cells showing an enzymatic activity after 3 h) and survival (total loss of cultivability after 2 or 3 h depending on the strains) was revealed and discussed. The effect of each metabolite on L. reuteri DSM 17938 was further investigated, displaying a drastic inhibition caused by 3-HPA, while 3-HP induced lower impact and only at acidic pH. PMID:26319567

  1. Acid rock drainage and climate change

    Nordstrom, D.K.

    2009-01-01

    Rainfall events cause both increases and decreases in acid and metals concentrations and their loadings from mine wastes, and unmined mineralized areas, into receiving streams based on data from 3 mines sites in the United States and other sites outside the US. Gradual increases in concentrations occur during long dry spells and sudden large increases are observed during the rising limb of the discharge following dry spells (first flush). By the time the discharge peak has occurred, concentrations are usually decreased, often to levels below those of pre-storm conditions and then they slowly rise again during the next dry spell. These dynamic changes in concentrations and loadings are related to the dissolution of soluble salts and the flushing out of waters that were concentrated by evaporation. The underlying processes, pyrite oxidation and host rock dissolution, do not end until the pyrite is fully weathered, which can take hundreds to thousands of years. These observations can be generalized to predict future conditions caused by droughts related to El Ni??o and climate change associated with global warming. Already, the time period for dry summers is lengthening in the western US and rainstorms are further apart and more intense when they happen. Consequently, flushing of inactive or active mine sites and mineralized but unmined sites will cause larger sudden increases in concentrations that will be an ever increasing danger to aquatic life with climate change. Higher average concentrations will be observed during longer low-flow periods. Remediation efforts will have to increase the capacity of engineered designs to deal with more extreme conditions, not average conditions of previous years.

  2. Role of lipase-generated free fatty acids in converting mesenteric lymph from a noncytotoxic to a cytotoxic fluid.

    Qin, Xiaofa; Dong, Wei; Sharpe, Susan M; Sheth, Sharvil U; Palange, David C; Rider, Therese; Jandacek, Ronald; Tso, Patrick; Deitch, Edwin A

    2012-10-15

    Recent studies have shown that mesenteric lymph plays a very important role in the development of multiple-organ dysfunction syndrome under critical conditions. Great efforts have been made to identify the biologically active molecules in the lymph. We used a trauma-hemorrhagic shock (T/HS) model and the superior mesenteric artery occlusion (SMAO) model, representing a global and a localized intestinal ischemia-reperfusion insult, respectively, to investigate the role of free fatty acids (FFAs) in the cytotoxicity of mesenteric lymph in rats. Lymph was collected before, during, and after (post) shock or SMAO. The post-T/HS and SMAO lymph, but not the sham lymph, manifested cytotoxicity for human umbilical vein endothelial cells (HUVECs). HUVEC cytotoxicity was associated with increased FFAs, especially the FFA-to-protein ratio. Addition of albumin, especially delipidated albumin, reduced this cytotoxicity. Lipase treatment of trauma-sham shock (T/SS) lymph converted it from a noncytotoxic to a cytotoxic fluid, and its toxicity correlated with the FFA-to-protein ratio in a fashion similar to that of the T/HS lymph, further suggesting that FFAs were the key components leading to HUVEC cytotoxicity. Analysis of lymph by gas chromatography revealed that the main FFAs in the post-T/HS or lipase-treated T/SS lymph were palmitic, stearic, oleic, and linoleic acids. When added to the cell culture at levels comparable to those in T/HS lymph, all these FFAs were cytotoxic, with linoleic acid being the most potent. In conclusion, this study suggests that lipase-generated FFAs are the key components resulting in the cytotoxicity of T/HS and SMAO mesenteric lymph. PMID:22899820

  3. CLIMATE CHANGE ADAPTATION IN ACID SULFATE LANDSCAPES

    Chuxia Lin

    2012-01-01

    Oxidation of sulfide minerals produces sulfuric acid and consequently creates Acid Sulfate Landscapes (ASLs), which represent one of the most degraded types of land-surface environments. Although acid sulfate-producing weathering is a naturally occurring process, it is markedly facilitated by human intervention. Mining is by far the dominant anthropogenic cause for the creation of inland acid sulfate footprints while land reclamation in coastal lowlands is the driver for the formation of coas...

  4. Digitally Controlled Converter with Dynamic Change of Control Law and Power Throughput

    Nesgaard, Carsten; Andersen, Michael Andreas E.; Nielsen, Nils

    2003-01-01

    substitution of analog controllers with their digital counterparts are considered. The outline of the paper is divided into two segments – the first being an experimental analysis of the timing behavior by means of code optimization – the second being an examination of the dynamics of incorporating two control......With the continuous development of faster and cheaper microprocessors the field of applications for digital control is constantly expanding. Based on this trend the paper at hand describes the analysis and implementation of multiple control laws within the same controller. Also, implemented within...... the control algorithm is a thermal monitoring scheme used for assessment of safe converter power throughput. An added benefit of this thermal monitoring is the possibility of software implemented analytic redundancy, which improves system fault resilience. Finally, reliability issues concerning the...

  5. Changes in vasopressin-converting aminopeptidase activity in the rat pineal gland during summer : Relationship to vasopressin contents

    Liu, B; Burbach, J. P. H.

    1988-01-01

    Vasopressin (VP)-converting aminopeptidase (VP-AP) activity and VP contents were measured in single rat pineal glands during the summer of two successive years. The peptidase activity decreased significantly in August. The lowest activity (±SEM) of 0.18±0.02 pmol·hour−1 was recorded on August 14, compared to the basal activity of 0.25±0.01 pmol·hour−1 in July and September of 1986. The change with similar percentage occurred in the same period of 1987. The specific activity of the enzyme in t...

  6. Initiation points for cellular deoxyribonucleic acid replication in human lymphoid cells converted by Epstein-Barr virus

    Replicon size was estimated in two Epstein-Barr virus (EBV)-negative human lymphoma lines, BJAB and Ramos, and four EBV-positive lines derived from the former ones by infection (conversion) with two viral strains, B95-8 and P3HR-1. Logarithmic cultures were pulse-labeled with [/sup -3/H]thymidine, and the deoxyribonucleic acid was spread on microscopic slides and autoradiographed by the method of Huberman and Riggs. Three of the four EBV-converted cell lines, BJAB/B95-8, Ra/B95-8, and Ra/HRIK, were found to have significantly shorter replicons (41, 21, 54% shorter, respectively), i.e., more initiation points, than their EBV-negative parents. BJAB/HRIK had replicons which were only slightly shorter (11%) than those of BJAB. However, analysis of track length demonstrated that extensive track fusion occurred during the labeling of BJAB/HRIK, implying that its true average replicon size is shorter than the observed value. The results indicate that in analogy to simian virus 40, EBV activates new initiation points for cellular DNA replication in EBV-transformed cells

  7. Laser signals' nonlinear change in fatty acids

    Ghelmez-Dumitru, M; Piscureanu, M; Sterian, A

    2003-01-01

    Previous works showed that thin layers of fatty acids and fatty acid-cholesterol mixtures behaved as optical liquid crystals, even at low incident laser power. The paper presents an experimental and computer study of laser signals, emergent from such samples, in presence of fluctuations. The optical emergent laser beams' features at different incident parameters were experimentally determined for different type (c.w. and pulsed) lasers, as for example helium-neon and Nd sup 3 sup + glass lasers. The results were correlated with the amount of cholesterol in mixtures and with their response in external electric field. These measurements are in all cases affected by fluctuations. We developed some computer-based procedures, by using the TableCurve3D from Jandel Scientific software and equations Runge-Kutta in MATLAB for taking into account these fluctuations.

  8. Interaction of Climate Change and Acid Deposition

    Wright, R. F.; Aherne, J.; Bishop, K.; Dillon, P. J.; Erlandsson, M.; Evans, C. D.; Forsius, M.; Hardekopf, D.W.; Helliwell, R. C.; Hruška, J.; Hutchins, M.; Kaste, O.; Kopáček, Jiří; Krám, P.; Laudon, H.; Moldan, F.; Rogora, M.; Sjoeng, A.M.S.; de Wit, H. A.

    - : Wiley-Blackwell, 2010 - (Kernan, M.; Battarbee, R.; Moss, B.), s. 152-179 ISBN 978-1-4051-7913-3 Grant ostatní: EU(XE) GOCE-CT-2003-505540 Institutional research plan: CEZ:AV0Z60170517 Keywords : climate change * recovery from acidification * water chemistry Subject RIV: DJ - Water Pollution ; Quality

  9. Reactivity and reaction rate ratio changes with moderator voidage in a light water high converter reactor lattice

    Integral reaction rate ratios and other k∞ related parameters have been measured in the first three cores of the experimental program on light water high converter reactor (LWHCR) test lattices in the PROTEUS reactor. The reference tight-pitch lattice consisted of two rod types, with an average fissile-plutonium enrichment of 6% and a fuel/moderator ratio of 2.0. The moderators were H2O, Dowtherm (simulating an H2O voidage of 42.5%), and air (100% void). Comparisons of the measured parameters have been made with calculational results based mainly on the use of two separate codes and their associated data libraries, namely, WIMS-D and EPRI-CPM. A reconstruction of individual components of the k-infinity void coefficient has been carried out on the basis of the measured changes with voidage of the various reaction rate ratios, as well as of k-infinity itself. The subsequent more detailed comparisons between experiment and calculation should provide a useful basis for resolving the conflicting calculational results that have been reported in the past for the void coefficient characteristics of LWHCRs. (author)

  10. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters

    Nogueira, C. A.; Paiva, A. P.; P.C. Oliveira; Costa, Maria Clara; Costa, Ana M. Rosa da

    2014-01-01

    The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, i...

  11. A comperative study on quality changes in positive, negative and combined switching strategies in control of three Phase Matrix Converter

    Mohammad Sarvi, Iman Soltani

    2013-07-01

    Full Text Available In this paper has used positive, negative and combined switching strategies for three phase ac/ac matrix converter.the author compares these strategies. The performance comparison of these three strategies is made under balanced operation. The simulation of three phase matrix converter feeding a three phase load was accomplished by means of the matlab/simulink software. After the simulation the comparison of the waveforms THD in three switching sequence is done. It must be mentioned that the duty cycle of the whole switches in the converter is according to Venturini switching algorithm.

  12. Substitution of a single amino acid (aspartic acid for histidine) converts the functional activity of human complement C4B to C4A

    The C4B isotype of the fourth component of human complement (C4) displays 3- to 4-fold greater hemolytic activity than does its other isotype C4A. This correlates with differences in their covalent binding efficiencies to erythrocytes coated with antibody and complement C1. C4A binds to a greater extent when C1 is on IgG immune aggregates. The differences in covalent binding properties correlate only with amino acid changes between residues 1101 and 1106 (pro-C4 numbering)-namely, Pro-1101, Cys-1102, Leu-1105, and Asp-1106 in C4A and Leu-1101, Ser-1102, Ile-1105, and His-1106 in C4B, which are located in the C4d region of the α chain. To more precisely identify the residues that are important for the functional differences, C4A-C4B hybrid proteins were constructed by using recombinant DNA techniques. Comparison of these by hemolytic assay and binding to IgG aggregates showed that the single substitution of aspartic acid for histidine at position 1106 largely accounted for the change in functional activity and nature of theformed. Surprisingly, substitution of a neutral residue, alanine, for histidine at position 1106 resulted in an increase in binding to immune aggregates without subsequent reduction in the hemolytic activity. This result strongly suggests that position 1106 is not catalytic as previously proposed but interacts sterically/electrostatically with potential acceptor sites and serves to select binding sites on potential acceptor molecules

  13. A comperative study on quality changes in positive, negative and combined switching strategies in control of three Phase Matrix Converter

    Mohammad Sarvi, Iman Soltani; Hossein Faramarzi

    2013-01-01

    In this paper has used positive, negative and combined switching strategies for three phase ac/ac matrix converter.the author compares these strategies. The performance comparison of these three strategies is made under balanced operation. The simulation of three phase matrix converter feeding a three phase load was accomplished by means of the matlab/simulink software. After the simulation the comparison of the waveforms THD in three switching sequence is done. It must be mentioned that the ...

  14. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters

    Highlights: • A new leaching process based on Cu2+/HCl media for recovering Pd and Rh from spent autocatalytic converters is presented. • Palladium and rhodium were efficiently leached, with attained maximum yields of 95% and 86%, respectively. • Temperature, time, and HCl and Cu2+ concentrations were found to be significant factors in the leaching of Pd and Rh. - Abstract: The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu2+ concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4 h, [HCl] = 6 M, [Cu2+] = 0.3 M)

  15. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters

    Nogueira, C.A., E-mail: carlos.nogueira@lneg.pt [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Paiva, A.P., E-mail: appaiva@fc.ul.pt [Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa (Portugal); Oliveira, P.C. [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Costa, M.C., E-mail: mcorada@ualg.pt [Centro de Ciências do Mar, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal); Costa, A.M. Rosa da, E-mail: amcosta@ualg.pt [Centro de Investigação em Química do Algarve, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal)

    2014-08-15

    Highlights: • A new leaching process based on Cu{sup 2+}/HCl media for recovering Pd and Rh from spent autocatalytic converters is presented. • Palladium and rhodium were efficiently leached, with attained maximum yields of 95% and 86%, respectively. • Temperature, time, and HCl and Cu{sup 2+} concentrations were found to be significant factors in the leaching of Pd and Rh. - Abstract: The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu{sup 2+} concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4 h, [HCl] = 6 M, [Cu{sup 2+}] = 0.3 M)

  16. Adipose tissue Fatty Acid patterns and changes in antrhropometry

    Dahm, Christina Catherine; Gorst-Rasmussen, Anders; Jakobsen, Marianne Uhre;

    2011-01-01

    Introduction Diets rich in n-3 long chain polyunsaturated fatty acids (LC-PUFA), but low in n-6 LC-PUFA and 18:1 trans-fatty acids (TFA), may lower the risk of overweight and obesity. These fatty acids have often been investigated individually. We explored associations between global patterns in...... women, respectively. Fatty acid patterns with high levels of TFA tended to be positively associated with changes in weight and WC for both sexes. Patterns with high levels of n-6 LC-PUFA tended to be negatively associated with changes in weight and WC in men, and positively associated in women....... Associations with patterns with high levels of n-3 LC-PUFA were dependent on the context of the rest of the fatty acid pattern. Conclusions Adipose tissue fatty acid patterns with high levels of TFA may be linked to weight gain, but patterns with high n-3 LC-PUFA did not appear to be linked to weight loss...

  17. Hyaluronic acid changes of the extracellular matrix in colon carcinoma

    Arab MR.; Allahyari A.; Sargolzaie Aval F.; Rafighdoost H; Karimi M

    2007-01-01

    Background: The extracellular matrix is a complex three-dimensional network of proteins and glycosaminoglycans, which have important roles in cellular physiology and cell-cell and cell-extracellular matrix interactions. Any changes in the extracellular matrix of tumors may be implicated in cellular transformation and metastasis. The aim of the present study was to identify changes in the hyaluronic acid of the stroma of colonic carcinoma.Methods: Paraffin blocks of 30 patients with colon carc...

  18. Changes in vasopressin-converting aminopeptidase activity in the rat pineal gland during summer : Relationship to vasopressin contents

    Liu, B.; Burbach, J.P.H.

    1988-01-01

    Vasopressin (VP)-converting aminopeptidase (VP-AP) activity and VP contents were measured in single rat pineal glands during the summer of two successive years. The peptidase activity decreased significantly in August. The lowest activity (±SEM) of 0.18±0.02 pmol·hour−1 was recorded on August 14, co

  19. Alternative method for thermal neutron flux measurements based on common boric acid as converter and Lr-15 detectors

    Palacios, D.; Greaves, E. D.; Sajo B, L.; Barros, H. [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apdo. Postal 89000, Caracas (Venezuela, Bolivarian Republic of); Ingles, R. [Universidad Nacional de San Antonio Abad del Cusco, Av. de la Cultura No. 733, Cusco (Peru)

    2010-02-15

    A method to determine the flux and angular distribution of thermal neutrons with the use of Lr-115 detectors was developed. The use of the Lr-115 detector involves the exposure of a pressed boric acid sample (tablet) as a target, in tight contact with the track detector, to a flux of thermalized neutrons. The self-absorption effects in thin films or foil type thermal neutron detectors can be neglected by using the Lr-115 detector and boric acid tablet setup to operate via backside irradiation. The energy window and the critical angle-residual energy curve were determined by comparisons between the experimental and simulated track parameters. A computer program was developed to calculate the detector registration efficiency, so that the thermal neutron flux can be calculated from the track densities induced in the Lr-115 detector using the derived empirical formula. The proposed setup can serves as directional detector of thermal neutrons. (Author)

  20. Alternative method for thermal neutron flux measurements based on common boric acid as converter and Lr-15 detectors

    A method to determine the flux and angular distribution of thermal neutrons with the use of Lr-115 detectors was developed. The use of the Lr-115 detector involves the exposure of a pressed boric acid sample (tablet) as a target, in tight contact with the track detector, to a flux of thermalized neutrons. The self-absorption effects in thin films or foil type thermal neutron detectors can be neglected by using the Lr-115 detector and boric acid tablet setup to operate via backside irradiation. The energy window and the critical angle-residual energy curve were determined by comparisons between the experimental and simulated track parameters. A computer program was developed to calculate the detector registration efficiency, so that the thermal neutron flux can be calculated from the track densities induced in the Lr-115 detector using the derived empirical formula. The proposed setup can serves as directional detector of thermal neutrons. (Author)

  1. Heterotrophic Production of Omega-3 Long-Chain Polyunsaturated Fatty Acids by Trophically Converted Marine Diatom Phaeodactylum tricornutum

    Mary L. Hamilton

    2016-03-01

    Full Text Available We have created via metabolic engineering a heterotrophic strain of Phaeodactylum tricornutum that accumulates enhanced levels of the high value omega-3 long chain polyunsaturated fatty acid (LC-PUFAs docosahexaenoic acid (DHA. This was achieved by generation of transgenic strains in which the Δ5-elongase from Ostreococcus tauri was co-expressed with a glucose transporter from the moss Physcomitrella patens. This double transformant has the capacity to grow in the dark in liquid medium supplemented with glucose and accumulate substantial levels of omega-3 LC-PUFAs. The effects of glucose concentrations on growth and LC-PUFA production of wild type and transformed strains cultivated in the light and dark were studied. The highest omega-3 LC-PUFAs accumulation was observed in cultures grown under mixotrophic conditions in the presence of 1% glucose (up to 32.2% of total fatty acids, TFA. Both DHA and EPA are detected at high levels in the neutral lipids of transgenic cells grown under phototrophic conditions, averaging 36.5% and 23.6% of TFA, respectively. This study demonstrates the potential for P. tricornutum to be developed as a viable commercial strain for both EPA and DHA production under mixo- and heterotrophic conditions.

  2. Heterotrophic Production of Omega-3 Long-Chain Polyunsaturated Fatty Acids by Trophically Converted Marine Diatom Phaeodactylum tricornutum.

    Hamilton, Mary L; Powers, Stephen; Napier, Johnathan A; Sayanova, Olga

    2016-03-01

    We have created via metabolic engineering a heterotrophic strain of Phaeodactylum tricornutum that accumulates enhanced levels of the high value omega-3 long chain polyunsaturated fatty acid (LC-PUFAs) docosahexaenoic acid (DHA). This was achieved by generation of transgenic strains in which the Δ5-elongase from Ostreococcus tauri was co-expressed with a glucose transporter from the moss Physcomitrella patens. This double transformant has the capacity to grow in the dark in liquid medium supplemented with glucose and accumulate substantial levels of omega-3 LC-PUFAs. The effects of glucose concentrations on growth and LC-PUFA production of wild type and transformed strains cultivated in the light and dark were studied. The highest omega-3 LC-PUFAs accumulation was observed in cultures grown under mixotrophic conditions in the presence of 1% glucose (up to 32.2% of total fatty acids, TFA). Both DHA and EPA are detected at high levels in the neutral lipids of transgenic cells grown under phototrophic conditions, averaging 36.5% and 23.6% of TFA, respectively. This study demonstrates the potential for P. tricornutum to be developed as a viable commercial strain for both EPA and DHA production under mixo- and heterotrophic conditions. PMID:27005636

  3. Postnatal changes of plasma amino acids in suckling pigs.

    Flynn, N E; Knabe, D A; Mallick, B K; Wu, G

    2000-09-01

    Amino acids, ammonia, urea, orotate, and nitrate plus nitrite (stable oxidation products of nitric oxide) were determined in plasma of 1- to 21-d-old suckling pigs. Jugular venous blood samples were obtained from pigs at 1, 3, 7, 14, and 21 d of age for analysis of plasma amino acids and metabolites by HPLC and enzymatic methods. Plasma concentrations of arginine and its immediate precursors (citrulline and ornithine) decreased (P Plasma concentrations of glutamine declined (P Plasma concentrations of branched-chain amino acids, threonine, and alanine decreased (P changes (P > 0.05) in plasma concentrations of other amino acids. Plasma concentrations of ammonia increased (P nitric oxide synthesis, our results of the decreased plasma concentrations of arginine and nitrate plus nitrite, as well as the increased plasma ammonia concentration, indicate a hitherto unrecognized deficiency of arginine in 7- to 21-d-old suckling pigs. Arginine is an essential amino acid for piglets and has a great potential to enhance neonatal growth; therefore, further studies are necessary to elucidate the mechanism responsible for arginine deficiency in sow-reared piglets and to identify hormonal and metabolic means for improving neonatal arginine nutrition and growth. PMID:10985412

  4. Role of brain glutamic acid metabolism changes in neurodegenerative pathologies

    Nina Pavlovna Kanunnikova

    2012-01-01

    Glutamic acid is an essential participant of brain metabolism. It is known that the glutamate is a neurotransmitter in a numerous part of the brain synapses and acts through various ionotropic or metabotropic receptors. Multiple alterations of the brain glutamate system are observed in both acute and chronic brain injures. Glutamate metabolism changes take place in many neurodegenerative pathologies, such as brain ischemia, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, amyot...

  5. Hydrogen converters

    The National Atomic Energy Commission of Argentina developed a process of 99Mo production from fission, based on irradiation of uranium aluminide targets with thermal neutrons in the RA-3 reactor of the Ezeiza Atomic Centre. These targets are afterwards dissolved in an alkaline solution, with the consequent liberation of hydrogen as the main gaseous residue. This work deals with the use of a first model of metallic converter and a later prototype of glass converter at laboratory scale, adjusted to the requirements and conditions of the specific redox process. Oxidized copper wires were used, which were reduced to elementary copper at 400 C degrees and then regenerated by oxidation with hot air. Details of the bed structure and the operation conditions are also provided. The equipment required for the assembling in cells is minimal and, taking into account the operation final temperature and the purge with nitrogen, the procedure is totally safe. Finally, the results are extrapolated for the design of a converter to be used in a hot cell. (author)

  6. Engineering of a novel hybrid enzyme: an anti-inflammatory drug target with triple catalytic activities directly converting arachidonic acid into the inflammatory prostaglandin E2

    Ruan, Ke-He; Cervantes, Vanessa; So, Shui-Ping

    2009-01-01

    Cyclooxygenase isoform-2 (COX-2) and microsomal prostaglandin E2 synthase-1 (mPGES-1) are inducible enzymes that become up-regulated in inflammation and some cancers. It has been demonstrated that their coupling reaction of converting arachidonic acid (AA) into prostaglandin (PG) E2 (PGE2) is responsible for inflammation and cancers. Understanding their coupling reactions at the molecular and cellular levels is a key step toward uncovering the pathological processes in inflammation. In this paper, we describe a structure-based enzyme engineering which produced a novel hybrid enzyme that mimics the coupling reactions of the inducible COX-2 and mPGES-1 in the native ER membrane. Based on the hypothesized membrane topologies and structures, the C-terminus of COX-2 was linked to the N-terminus of mPGES-1 through a transmembrane linker to form a hybrid enzyme, COX-2-10aa-mPGES-1. The engineered hybrid enzyme expressed in HEK293 cells exhibited strong triple-catalytic functions in the continuous conversion of AA into PGG2 (catalytic-step 1), PGH2 (catalytic-step 2) and PGE2 (catalytic-step 3), a pro-inflammatory mediator. In addition, the hybrid enzyme was also able to directly convert dihomo-gamma-linolenic acid (DGLA) into PGG1, PGH1 and then PGE1 (an anti-inflammatory mediator). The hybrid enzyme retained similar Kd and Vmax values to that of the parent enzymes, suggesting that the configuration between COX-2 and mPGES-1 (through the transmembrane domain) could mimic the native conformation and membrane topologies of COX-2 and mPGES-1 in the cells. The results indicated that the quick coupling reaction between the native COX-2 and mPGES-1 (in converting AA into PGE2) occurred in a way so that both enzymes are localized near each other in a face-to-face orientation, where the COX-2 C-terminus faces the mPGES-1 N-terminus in the ER membrane. The COX-2-10aa-mPGES-1 hybrid enzyme engineering may be a novel approach in creating inflammation cell and animal models, which

  7. Hyaluronic acid changes of the extracellular matrix in colon carcinoma

    Arab MR.

    2007-10-01

    Full Text Available Background: The extracellular matrix is a complex three-dimensional network of proteins and glycosaminoglycans, which have important roles in cellular physiology and cell-cell and cell-extracellular matrix interactions. Any changes in the extracellular matrix of tumors may be implicated in cellular transformation and metastasis. The aim of the present study was to identify changes in the hyaluronic acid of the stroma of colonic carcinoma.Methods: Paraffin blocks of 30 patients with colon carcinoma (10 patients at each histological grade were chosen from the pathology file of Khatam-Al-Anbia Hospital in Zahedan, Iran. Tissue sections (5-6 micrometers thick were stained with hematoxylin-eosin and the alcian blue critical electrolyte concentration histochemical technique at pH=5.8. The intensity of the staining in each section was graded as 1, 2 or 3, referring to low, moderate or severe staining reactivities, respectively. Statistical data was analyzed with nonparametric tests by SPSS (ver. 10 and histopathological reports were prepared.Results: The results of this study showed that there is a good correlation between histopathological grading and staining intensity of tumoral stroma for hyaluronic acid (p<0.005. Analysis using the Mann Whitney test revealed significant differences between staining grades 1 and 3 and grades 2 and 3 (p<0.005 and p<0.002, respectively, although there was no significant difference between staining grades 1 and 2 for hyaluronic acid.Conclusions: The difference in staining intensity of the stroma in colon carcinoma is a result of different amounts of hyaluronic acid in stroma, indicating that increased levels of hyaluronic acid are associated with the invasion and metastasis of neoplastic cells.

  8. Chemical changes in an oxisol treated with pyroligneous acid

    Aluísio Hideki Togoro

    2014-04-01

    Full Text Available The use of pyroligneous acid (PA, a by-product of charcoal production, is an ancient practice applied in agriculture to control soil and plant pests and diseases. However, little is known about the chemical alterations that this product may cause on treated soil. Thus, the present work aimed to evaluate the effect of PA concentrations on soil ions movement and to verify possible soil chemical properties changes. Detachable columns were filled with Oxisol, submitted to application of 5 PA concentrations (0, 1, 2, 4, 8% v/v, followed by water infiltration in an amount corresponding to 1.5 times the soil total pore volume, and evaluated the soil of four depths (0-10, 10-20, 20-30, 30-40cm and the leachate. The use of pyroligneous acid in concentrations up to 2 % (v/v induces only slight decrease of k, Mg, basis saturation and total cation exchange capacity, in the 0-20 cm soil layer. The application of 4 % (v/v and 8 % (v/v pyroligneous acid induces severe increase on the potential acidity, and the decrease on the pH, basis saturation, total cation exchange capacity, and Ca concentration, in the layer of 0-20 cm soil. The P and K concentration reduces in the 0-20 cm soil layer by increasing from 1% to 8% the concentration of pyroligneous acid solution applied on soil surface. By increasing the PA concentration applied on the soil, there is increase of acidity, organic matter, P, K, Ca, and Mg, and decrease of sulfate in the leachate.

  9. Effects of decreasing acid deposition and climate change on acid extremes in an upland stream

    C. D. Evans

    2008-03-01

    Full Text Available This study assesses the major chemical processes leading to acid extremes in a small, moorland stream in mid-Wales, UK, which has been monitored since 1979. Results suggest that base cation (mainly calcium dilution, the "sea-salt effect", and elevated nitrate pulses, are the major causes of seasonal/episodic minima in acid neutralising capacity (ANC, and that the relative importance of these drivers has remained approximately constant during 25 years of decreasing acid deposition and associated long-term chemical recovery. Many of the chemical variations causing short-term reductions in stream acidity, particularly base cation dilution and organic acid increases, are closely related to changes in water-flowpath and therefore to stream discharge. Changes in the observed pH-discharge relationship over time indicate that high-flow pH has increased more rapidly than mean-flow pH, and therefore that episodes have decreased in magnitude since 1980. However a two-box application of the dynamic model MAGIC, whilst reproducing this trend, suggests that it will not persist in the long term, with mean ANC continuing to increase until 2100, but the ANC of the upper soil (the source of relatively acid water during high-flow episodes stabilising close to zero beyond 2030. With climate change predicted to lead to an increase in maximum flows in the latter half of the century, high-flow related acid episodes may actually become more rather than less severe in the long term, although the model suggests that this effect may be small. Two other predicted climatic changes could also detrimentally impact on acid episodes: increased severity of winter "sea-salt" episodes due to higher wind speeds during winter storms; and larger sulphate pulses due to oxidation of reduced sulphur held in organic soils, during more extreme summer droughts. At the Gwy, the near-coastal location and relatively small extent of peat soils suggest that sea-salt episodes may have the

  10. Wavelength Converters

    Kloch, Allan; Hansen, Peter Bukhave; Wolfson, David;

    1999-01-01

    After a short introduction to the different requirements to and techniques for wavelength conversion, focus is on cross-gain and cross-phase modulation in SOAs and SOA based interferometers. Aspects like jitter accumulation, regeneration and conversion to the same wavelength is discussed. It is...... extinction ratio of ~10 dB.The regenerative capabilities of the cross-phase converters are described and verified experimentally at 20 Gbit/s, where the noise redistribution and improvement of the signal-to-noise ratio clearly is demonstrated by controlling the input power to an EDFA. In a similar experiment...

  11. Acid-induced changes of brain protein buffering

    Kraig, Richard P.; Wagner, Robert J.

    1987-01-01

    Excessive cellular acidosis is thought to enhance destruction of brain from ischemia. Protein denaturation may contribute to such injury although the behavior of brain proteins to acidosis is poorly defined. As a first approach to detect acid-induced changes in brain proteins and to characterize buffer content, homogenates were acidified for 20 min (as low as pH 3.1), returned to baseline pH (6.9), and then titrated. Titration curves show a significant (P < 0.0001) and permanent increase in b...

  12. Docosahexaenoic acid and eicosapentaenoic acid induce changes in the physical properties of a lipid bilayer model membrane.

    Onuki, Yoshinori; Morishita, Mariko; Chiba, Yoshiyuki; Tokiwa, Shinji; Takayama, Kozo

    2006-01-01

    We investigated the effect of fatty acids such as stearic acid (SA, 18:0), oleic acid (OA, 18:1), eicosapentaenoic acid (EPA, 20:5), and docosahexaenoic acid (DHA, 22:6) on a dipalmitoylphosphatidylcholine (DPPC) bilayer by determining the phase transition temperature, fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH), and detergent insolubility. Treatment with unsaturated fatty acid broadened and shifted the phase transitions of the DPPC bilayer to a lower temperature. The phase transition temperature and the value of fluorescence anisotropy of DPH at 37 degrees C decreased progressively with increasing treatment amounts of unsaturated fatty acid. A large amount of the DPPC bilayer treated with unsaturated fatty acid was dissolved in Triton X-100, obtaining a low level of detergent insolubility. These modifications of the bilayer physical properties were most pronounced with DHA and EPA treatment. These data show that unsaturated fatty acids, particularly DHA and EPA, induce a marked change in the lipid bilayer structure. The composition of fatty acids in the DPPC bilayer was similar after treatment with various unsaturated fatty acids, suggesting that the different actions of unsaturated fatty acids are attributed to change in the molecular structure (e.g., kinked conformation by double bonds). We further explored the change in physical properties induced by fatty acids dispersed in a water-in-oil-in-water multiple emulsion and found that unsaturated fatty acids acted efficiently on the DPPC bilayer, even when incorporated in emulsion form. PMID:16394552

  13. The Study of Organic Acids Changes with Different Lactic Acid Starters During Iranian White Brined Cheese Ripening

    M.B. Habbibi

    2002-04-01

    Full Text Available For Iranian fermented cheese processing and ripening, different lactic acid bacteria (LAB that affect on the physicochemical properties and hence the organoleptic characteristics of the cheese is used. Determination of physicochemical changes of cheese, particularly, organic acids is of importance. In this study five cheese formulas with five different group of cheese starters were processed and ripened in 8% brine during two months at 12±1 °C. HPLC analysis of organic acids were accomplished, using SCR-101H column with U. V. detector at 214 nm and quantified with high purity standards concerning each organic acid recovery. Pyruvic, orotic, citric, propionic, lactic, butyric and acetic acids were analyzed after 1, 10, 20, 30, 40, 50 and 60 days of processing and storage. Each determined organic acid exhibited a specific profile changes during cheese ripening. Lactic acid was dominant organic acid in all samples. Total organic acids were increased significantly after 30 days of storage, but decreased up to the end of ripening. The profile changes of organic acids which was similar in all samples with different amounts related to dominant lactic acid with about 80-90% of the total organic acids. The aromatic mesophile group, CH-N-O1(including Lactococci and Leuconostocs and Lactobacillus casei and also the mixed mesophiles plus thermophile starters group, CH-1 (including Lactobacillus bulgaricus and Streptococcus salivarius ssp. thermophilus caused a significant decrease in citric acid and increase in acetic and propionic acid in related cheese samples compared with other cheeses (P < 0.01. But cheese containing only thermophiles or the mixed thermophile and mesophile (code 54 revealed a significant increase in butyric acid. In all samples the changes in pyruvic acid content was irregular. The ripening period of cheese samples were determined by the stepwise regression analysis in relation to their exact amount of organic acids.

  14. Fractional Watt AMTEC Converter

    Hunt, T. K.; Rasmussen, J. R.

    2006-01-01

    We report here the long term performance of a small, multi-tube AMTEC converter. This converter was designed to operate and produce approximately 12 watt of electrical output from a small, 4 to 6 watt radioisotope heat source for remote power applications. It was built and put on test in 1999 using electrical heaters as stand-ins for the radioisotope capsule. Since that time it has accumulated more than 5 years of run time at an input heater temperature of 700 °C, with numerous thermal cycles to ambient that were generally related to grid power failures or physical moves of the test apparatus. The power output has remained, with variations due to orientation changes and minor variations due to small temperature changes, essentially constant at 0.40 W to 0.60 W over the test period and operation is ongoing. The converter casing and mechanical structure was fabricated from 316 SS and the electrodes are sputtered titanium nitride films. Separate static tests of a multilayer insulation package suitable for use with the converter showed the capability to reach 700 °C with a thermal input of < 4 watts.

  15. Mutation induced changes in essential fatty acids composition in Indian mustard (Brassica juncea L.)

    Changes in fatty acid composition were studied in M2 generation using two varieties (Varuna and BR-40) of Indian mustard (Brassica juncea L.). Fatty acid profile indicated inverse relationship between erucic acid and oleic acid in Varuna progenies derived from higher doses of gamma rays whereas in BR-40, it was true for all the treatments. Selection of mutants having high oleic and linoleic acid and low erucic and eicosenoic acid was preferred for further quality improvement in Indian mustard. (author)

  16. Reducing cold-start emission from internal combustion engines by means of a catalytic converter embedded in a phase-change material

    Korin, E. [Ben-Gurion Univ. of the Negev, Dept. of Chemical Engineering, Beer-Sheva (Israel); Reshef, R.; Tschernichovesky, D.; Sher, E. [Ben-Gurion Univ. of the Negev, Dept. of Mechanical Engineering, Beer-Sheva (Israel)

    1999-11-01

    Under normal operating conditions, catalytic converters appear to be the most effective means of reducing air pollution from internal combustion (IC) engines. The conversion efficiency, however, declines very steeply for temperatures below about 350degC and is practically zero during the starting and warming-up period. Improving the conversion efficiency under these conditions is important, particularly in large cities, where the number of startings per vehicles per day tend to be high. Among the more successful solutions are preheating of the catalyst electrically, warming up of the catalyst in an external combustion chamber, installation of an auxiliary small-capacity catalytic converter, and employment of an adsorbing unit between two catalysts. Although these methods are quite effective, their disadvantage lies in the fact that they require an external energy source, an additional component (a control unit) or a three-stage catalyst. In the present work an investigation was made of a solution based on the exploitation of thermal capacitance to keep the catalyst temperature high during off-operation periods. A phase-change material (PCM) with a transition temperature of 352.7degC, which is slightly above the light-off temperature of the metallic catalyst, was specially formulated, and a system comprising a catalytic converter embedded in the PCM was designed and tested. Under normal engine operating conditions, some of the thermal energy of the exhaust gases was stored in the PCM. During the time that the vehicle was not in use, the PCM underwent partial solidification, and the latent heat thus produced was exploited to maintain the catalyst temperature within the desired temperature range for maximum conversion efficiency. (Author)

  17. Maximized PUFA measurements improve insight in changes in fatty acid composition in response to temperature

    Van Dooremalen, C.; Pel, R.; Ellers, J.

    2009-01-01

    A general mechanism underlying the response of ectotherms to environmental changes often involves changes in fatty acid composition. Theory predicts that a decrease in temperature causes an increase in unsaturation of fatty acids, with an important role for long-chain poly-unsaturated fatty acids (P

  18. Interaction of Fatty Acid Genotype and Diet on Changes in Colonic Fatty Acids in a Mediterranean Diet Intervention Study

    Porenta, Shannon R.; Ko, Yi-An; Gruber, Stephen B.; Mukherjee, Bhramar; Baylin, Ana; Raskin, Leonid; Ren, Jianwei; Djuric, Zora

    2013-01-01

    A Mediterranean diet increases intakes of n-3 and n-9 fatty acids and lowers intake of n-6 fatty acids. This can impact colon cancer risk since n-6 fatty acids are metabolized to pro-inflammatory eicosanoids. The purpose of this study was to evaluate interactions of polymorphisms in the fatty acid desaturase genes, FADS1 and FADS2, and changes in diet on fatty acid concentrations in serum and colon. A total of 108 individuals at increased risk of colon cancer were randomized to either a Medit...

  19. Acidic deposition: State of science and technology. Report 11. Historical changes in surface-water acid-base chemistry in response to acidic deposition. Final report

    The objectives of the analyses reported in the State of Science report are to: identify the lake and stream populations in the United States that have experienced chronic changes in biologically significant constituents of surface water chemistry (e.g. pH, Al) in response to acidic deposition; quantify biologically meaningful historical changes in chronic surface water chemistry associated with acidic deposition, with emphasis on ANC, pH, and Al; estimate the proportion of lakes nor acidic that were not acidic in pre-industrial times; estimate the proportional response of each of the major chemical constituents that have changed in response to acidic deposition using a subset of statistically selected Adirondack lakes for which paleolimnological reconstructions of pre-industrial surface water chemistry have been performed; evaluate and improve, where appropriate and feasible, empirical models of predicting changes in ANC; and evaluate the response of seepage lakes to acidic deposition

  20. Adipose tissue fatty acid patterns and changes in anthropometry

    Dahm, Christina Catherine; Gorst-Rasmussen, Anders; Jakobsen, Marianne Uhre;

    2011-01-01

    Diets rich in n-3 long chain polyunsaturated fatty acids (LC-PUFA), but low in n-6 LC-PUFA and 18:1 trans-fatty acids (TFA), may lower the risk of overweight and obesity. These fatty acids have often been investigated individually. We explored associations between global patterns in adipose tissue...

  1. Chronic gamma radiation-induced changes in the content of fatty acids in spring rape seeds

    Chronic gamma irradiation of spring rape plants having no erucic acid and eicosanoic acid in seed oil induced changes both in the growth and in the morphological composition of the plants. The contents of erucic acid and eicosanoic acid did not increase. The greatest changes occurred in unsaturated acids, especially in macromutants resulting from irradiated plants located in the closest proximity of the radiation source or in places with the most significant plant growth inhibition. Nutants with a low, or a high, content of linolenic acid were obtained. (author)

  2. Soybean Aphid Infestation Induces Changes in Fatty Acid Metabolism in Soybean.

    Charles Kanobe

    Full Text Available The soybean aphid (Aphis glycines Matsumura is one of the most important insect pests of soybeans in the North-central region of the US. It has been hypothesized that aphids avoid effective defenses by inhibition of jasmonate-regulated plant responses. Given the role fatty acids play in jasmonate-induced plant defenses, we analyzed the fatty acid profile of soybean leaves and seeds from aphid-infested plants. Aphid infestation reduced levels of polyunsaturated fatty acids in leaves with a concomitant increase in palmitic acid. In seeds, a reduction in polyunsaturated fatty acids was associated with an increase in stearic acid and oleic acid. Soybean plants challenged with the brown stem rot fungus or with soybean cyst nematodes did not present changes in fatty acid levels in leaves or seeds, indicating that the changes induced by aphids are not a general response to pests. One of the polyunsaturated fatty acids, linolenic acid, is the precursor of jasmonate; thus, these changes in fatty acid metabolism may be examples of "metabolic hijacking" by the aphid to avoid the induction of effective defenses. Based on the changes in fatty acid levels observed in seeds and leaves, we hypothesize that aphids potentially induce interference in the fatty acid desaturation pathway, likely reducing FAD2 and FAD6 activity that leads to a reduction in polyunsaturated fatty acids. Our data support the idea that aphids block jasmonate-dependent defenses by reduction of the hormone precursor.

  3. Changes in mineralogical and leaching properties of converter steel slag resulting from accelerated carbonation at low CO2 pressure

    Steel slag can be applied as substitute for natural aggregates in construction applications. The material imposes a high pH (typically 12.5) and low redox potential (Eh), which may lead to environmental problems in specific application scenarios. The aim of this study is to investigate the potential of accelerated steel slag carbonation, at relatively low pCO2 pressure (0.2 bar), to improve the environmental pH and the leaching properties of steel slag, with specific focus on the leaching of vanadium. Carbonation experiments are performed in laboratory columns with steel slag under water-saturated and -unsaturated conditions and temperatures between 5 and 90C. Two types of steel slag are tested; free lime containing (K3) slag and K1 slag with a very low free lime content. The fresh and carbonated slag samples are investigated using a combination of leaching experiments, geochemical modelling of leaching mechanisms and microscopic/mineralogical analysis, in order to identify the major processes that control the slag pH and resulting V leaching. The major changes in the amount of sequestered CO2 and the resulting pH reduction occurred within 24 h, the free lime containing slag (K3-slag) being more prone to carbonation than the slag with lower free lime content (K1-slag). While carbonation at these conditions was found to occur predominantly at the surface of the slag grains, the formation of cracks was observed in carbonated K3 slag, suggesting that free lime in the interior of slag grains had also reacted. The pH of the K3 slag (originally pH ± 12.5) was reduced by about 1.5 units, while the K1 slag showed a smaller decrease in pH from about 11.7 to 11.1. However, the pH reduction after carbonation of the K3 slag was observed to lead to an increased V-leaching. Vanadium leaching from the K1 slag resulted in levels above the limit values of the Dutch Soil Quality Decree, for both the untreated and carbonated slag. V-leaching from the carbonated K3 slag remained

  4. Changes in mineralogical and leaching properties of converter steel slag resulting from accelerated carbonation at low CO2 pressure

    Highlights: → Accelerated carbonation studied to improve environmental properties of steel slag. → Carbonation found to occur predominantly at surface of the steel slag grains. → Combined geochemical modelling and mineral analysis revealed controlling processes. → Enhanced V-leaching with di-Ca silicate (C2S) dissolution identified as major source. → Identified mineral transformations provide guidance for further quality improvement. - Abstract: Steel slag can be applied as substitute for natural aggregates in construction applications. The material imposes a high pH (typically 12.5) and low redox potential (Eh), which may lead to environmental problems in specific application scenarios. The aim of this study is to investigate the potential of accelerated steel slag carbonation, at relatively low pCO2 pressure (0.2 bar), to improve the environmental pH and the leaching properties of steel slag, with specific focus on the leaching of vanadium. Carbonation experiments are performed in laboratory columns with steel slag under water-saturated and -unsaturated conditions and temperatures between 5 and 90 oC. Two types of steel slag are tested; free lime containing (K3) slag and K1 slag with a very low free lime content. The fresh and carbonated slag samples are investigated using a combination of leaching experiments, geochemical modelling of leaching mechanisms and microscopic/mineralogical analysis, in order to identify the major processes that control the slag pH and resulting V leaching. The major changes in the amount of sequestered CO2 and the resulting pH reduction occurred within 24 h, the free lime containing slag (K3-slag) being more prone to carbonation than the slag with lower free lime content (K1-slag). While carbonation at these conditions was found to occur predominantly at the surface of the slag grains, the formation of cracks was observed in carbonated K3 slag, suggesting that free lime in the interior of slag grains had also reacted. The p

  5. A Single Amino Acid Change (Asp 53→ Ala53) Converts Survivin from Anti-apoptotic to Pro-apoptotic

    Song, Zhiyin; Liu, Shixin; He, He; Hoti, Naser; Wang, Yi; Feng, Shanshan; Wu, Mian

    2004-01-01

    Survivin is a member of the inhibitor of apoptosis protein (IAP) family that has been implicated in both apoptosis inhibition and cell cycle control. Recently, Survivin has attracted growing attention because of its tumor-specific expression and potential applications in tumor therapy. However, its inhibitory mechanism and subcellular localization remain controversial. Here, we report a novel Survivin mutant Surv-D53A, which displays a function opposite to Survivin and a distinctive subcellular distribution compared with its wild-type counterpart. Surv-D53A was shown to induce apoptosis in a p53-independent manner, indicating that tumor suppressor p53 is not involved in its apoptosis pathway. Surv-D53A was shown to markedly sensitize apoptosis induced by TRAIL, doxorubicin, and RIP3. We also demonstrated that similar to wild-type Survivin, Surv-D53A was localized in cytoplasm in interphase and to midbody at telophase. However, it fails to colocalize in chromosomes with Aurora-B in metaphase as wt-Survivin. Surv-D53A mutant is less stable than wt-Survivin and is degraded more rapidly by ubiquitin-proteasome pathway. Additionally, we found that Surv-D53A interacts with wt-Survivin to form heterodimer or with itself to form mutant homodimer, which may account for the loss of its antiapoptotic function. Finally, unlike Survivin*Survivin, neither Surv-D53A*Survivin nor Surv-D53A*Surv-D53A is able to bind to Smac/DIABLO, which may explain the underlying mechanism for its abolishment of antiapoptotic activity of Survivin. PMID:14699067

  6. A Single Amino Acid Change (Asp 53→ Ala53) Converts Survivin from Anti-apoptotic to Pro-apoptotic

    Song, Zhiyin; Liu, Shixin; He, He; Hoti, Naser; Wang, Yi; Feng, Shanshan; Wu, Mian

    2004-01-01

    Survivin is a member of the inhibitor of apoptosis protein (IAP) family that has been implicated in both apoptosis inhibition and cell cycle control. Recently, Survivin has attracted growing attention because of its tumor-specific expression and potential applications in tumor therapy. However, its inhibitory mechanism and subcellular localization remain controversial. Here, we report a novel Survivin mutant Surv-D53A, which displays a function opposite to Survivin and a distinctive subcellul...

  7. Interaction of fatty acid genotype and diet on changes in colonic fatty acids in a Mediterranean diet intervention study.

    Porenta, Shannon R; Ko, Yi-An; Gruber, Stephen B; Mukherjee, Bhramar; Baylin, Ana; Ren, Jianwei; Djuric, Zora

    2013-11-01

    A Mediterranean diet increases intakes of n-3 and n-9 fatty acids and lowers intake of n-6 fatty acids. This can impact colon cancer risk as n-6 fatty acids are metabolized to proinflammatory eicosanoids. The purpose of this study was to evaluate interactions of polymorphisms in the fatty acid desaturase (FADS) genes, FADS1 and FADS2, and changes in diet on fatty acid concentrations in serum and colon. A total of 108 individuals at increased risk of colon cancer were randomized to either a Mediterranean or a Healthy Eating diet. Fatty acids were measured in both serum and colonic mucosa at baseline and after six months. Each individual was genotyped for four single-nucleotide polymorphisms in the FADS gene cluster. Linear regression was used to evaluate the effects of diet, genotype, and the diet by genotype interaction on fatty acid concentrations in serum and colon. Genetic variation in the FADS genes was strongly associated with baseline serum arachidonic acid (n-6) but serum eicosapentaenoic acid (n-3) and colonic fatty acid concentrations were not significantly associated with genotype. After intervention, there was a significant diet by genotype interaction for arachidonic acid concentrations in colon. Subjects who had all major alleles for FADS1/2 and were following a Mediterranean diet had 16% lower arachidonic acid concentrations in the colon after six months of intervention than subjects following the Healthy Eating diet. These results indicate that FADS genotype could modify the effects of changes in dietary fat intakes on arachidonic acid concentrations in the colon. PMID:24022589

  8. Changes in lipid composition, fatty acid profile and lipid oxidative stability during Cantonese sausage processing.

    Qiu, Chaoying; Zhao, Mouming; Sun, Weizheng; Zhou, Feibai; Cui, Chun

    2013-03-01

    Lipid composition, fatty acid profile and lipid oxidative stability were evaluated during Cantonese sausage processing. Free fatty acids increased with concomitant decrease of phospholipids. Total content of free fatty acids at 72 h in muscle and adipose tissue was 7.341 mg/g and 3.067 mg/g, respectively. Total amount of saturated, monounsaturated and polyunsaturated fatty acids (SFA, MUFA, and PUFA) in neutral lipid exhibited a little change during processing, while the proportion of PUFA significantly decreased in the PL fraction. The main triacylglycerols were POO+SLO+OOO, PSO (P = palmitic acid, O = oleic acid, L = linoleic acid, S = stearic acid), and a preferential hydrolysis of palmitic, oleic and linoleic acid was observed. Phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the main components of phospholipids and PE exhibited the most significant degradation during processing. Thiobarbituric acid values (TBARS) increased while peroxide values and hexanal contents varied during processing. PMID:23273460

  9. The Crystalline Changes of Starch from Rhizoma Dioscorea by Acid Hydrolysis

    Shu Jun WANG; Wen Yuan GAO; Jing Lin YU; Pei Gen XIAO

    2006-01-01

    The changes in crystalline properties of starch from Rhizoma Dioscorea by acid hydrolysis was characterized by X-Ray diffractometry (XRD). The results revealed that the crystalline type of Rhizoma Dioscorea starch changed from C-type to A-type after 16 days of the acid hydrolysis. This phenomenon was different from that of other starches subjected to the acid hydrolysis. The results revealed that the B-polymorphs of C-type starch constituted the amorphous regions while the crystalline areas were mainly composed of A-polymorphs. The degree of crystallinity of the acid-thinned starch increased gradually with the time of acid hydrolysis.

  10. Compositional changes of proteins and amino acids in germinating coffee seeds

    Milton Massao Shimizu; Paulo Mazzafera

    2000-01-01

    Endosperm is the main reserve tissue in coffee seeds. Coffee (Coffea arabica L.) seeds were germinated for six weeks and qualitative and quantitative changes in amino acids and proteins were investigated. The total content of free amino acids were reduced during germination, however, protein content remained constant. SDS-PAGE profiles showed that legumin-like proteins became less stained in the last weeks. Asparagine, glutamic acid, aspartic acid, alanine and lysine were the major free amino...

  11. Dietary Fatty Acids: Is it Time to Change the Recommendations?

    Nettleton, Joyce A; Lovegrove, Julie A; Mensink, Ronald P; Schwab, Ursula

    2016-01-01

    Limiting the saturated fatty acid (SAFA) consumption forms the basis of dietary fat recommendations for heart health, despite several meta-analyses demonstrating no link between dietary SAFA and the risk of cardiovascular disease (CVD). Three experts on dietary fat and health discussed the evidence of reducing SAFA intake at a symposium of the Federation of European Nutrition Societies in Berlin, Germany, October 23, 2015. Ronald P. Mensink, Maastricht University, the Netherlands, discussed the evidence linking dietary fatty acids and CVD risk. He emphasized the importance of the replacement nutrient(s) when SAFA intake is reduced. Julie Lovegrove, University of Reading, UK, addressed the question of whether higher intakes of unsaturated fatty acids are beneficial. She discussed the replacement of SAFA by polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA), noting the reduction in CVD risk with PUFA replacement and in CVD risk markers with MUFA replacement of SAFA. Ursula Schwab, University of Eastern Finland, Kuopio, Finland, discussed the importance of dietary patterns in achieving reduced risk of CVD, observing that several dietary patterns following the principles of a health-promoting diet and adapted to local customs, food preferences and seasonality are effective in reducing the risk of CVD, type 2 diabetes and other chronic diseases. This paper summarizes the symposium presentations. PMID:27251664

  12. Diurnal changes in serum unconjugated bile acids in normal man.

    Setchell, K D; Lawson, A M; Blackstock, E J; Murphy, G M

    1982-01-01

    Unconjugated bile acids were measured using gas chromatography-mass spectrometry in the serum of two subjects throughout a 24 hour period and in two other subjects over a six hour period after breakfast. Unconjugated bile acids were found in all samples of serum and included cholic, chenodeoxycholic, deoxycholic, 3 beta, 7 alpha-dihydroxy-5 beta-cholanic (iso-chenodeoxycholic), ursodeoxycholic, 3 beta, 7 beta-dihydroxy-5 beta-cholanic (iso-ursodeoxycholic), 3 beta-hydroxy-5-cholenoic, and lit...

  13. Glucose supplementation-induced changes in the Auxenochlorella protothecoides fatty acid composition suitable for biodiesel production.

    Krzemińska, Izabela; Oleszek, Marta

    2016-10-01

    This study evaluates the effect of different concentrations of glucose supplementation on growth, lipid accumulation, and the fatty acid profile in the Auxenochlorella protothecoides. Addition of glucose promoted the growth rate and decreased the chlorophyll content. Compared with photoautotrophic cells, an increase in the lipid content was observed in mixotrophic cells. The glucose addition induced changes in the fatty acid profile. Higher content of saturated fatty acids was found in the case of cells growing in the glucose-free medium. Oleic acid was the predominant component in mixotrophic cells supplemented with 5gL(-1) glucose, while linoleic acids dominated in cultures supplemented with both 1 and 3gL(-1) glucose. The use of glucose was associated with decreased levels of linolenic acid and PUFA. The changes in the fatty acid profile in mixotrophic cells are favourable for biodiesel production. PMID:27485282

  14. Changes in physicochemical characteristics and free amino acids of hawthorn (Crataegus pinnatifida) fruits during maturation.

    Li, Wei-Qin; Hu, Qing-Ping; Xu, Jian-Guo

    2015-05-15

    In this study, changes in physicochemical characteristics associated with fruit quality and free amino acids were investigated during maturation of hawthorn fruits. Significant differences in these parameters were found during maturation. The color turned progressively from mature green to semi-red, to reach bright red; the shape changed gradually from oval to round or approached round; the size, weight, and edible part (flesh/core ratio) of hawthorns increased while the density of intact fruits did not change. The content of moisture, total soluble sugars, soluble pectin, reduced ascorbic acid, total ascorbic acid, fructose, and sucrose increased while crude protein content decreased significantly. The levels of starch, sucrose, titratable acidity, protopectin, pectin, total free amino acids, and total essential amino acids initially increased and then decreased gradually during maturation. The outcomes of this study provide additional and useful information for fresh consumption and processing as well as utilization of dropped unripe hawthorn fruits. PMID:25577050

  15. Lactic acid bacteria in a changing legislative environment

    Feord, J.

    2002-01-01

    The benefits of using lactic acid bacteria in the food chain, both through direct consumption and production of ingredients, are increasingly recognised by the food industry and consumers alike. The regulatory environment surrounding these products is diverse, covering foods and food ingredients, pr

  16. Dynamic change of organic acids secreted from wheat roots in Mn deficiency

    Zheng FANG; Zhenfeng AN; Yingli LI

    2008-01-01

    Through solution culture experiment and liquid chromatogram technique, two wheat (Triticum aestivum L.) genotypes with different tolerances to Mn deficiency were used to study the dynamic change of organic acids secreted from wheat root in the conditions of no Mn, low Mn and normal Mn supply. Nine kinds of organic acids were measured in wheat root exudate. The results showed that there were significant differences of organic acids in root exudate between tolerant genotype and susceptible genotype under Mn-stressed conditions. Tolerant genotype 9023 secreted more organic acids from the plant roots than susceptible genotype CM28. The main organic acid exudate included tartaric acid, malic acid, acetic acid, maleic acid and fumaric acid. Of all these acids, the amounts of tartaric acid and malic acid in root exudate showed significant differences between the tolerant genotype and susceptible genotype under Mn-stressed conditions. The results also indicated that secreting organic acids into root rhizosphere was an active response to Mn deficiency for the tolerant genotype of wheat.

  17. Dietary fatty acids: is it time to change the recommendations

    Nettleton, J.A.; Lovegrove, J. A. (Julie A.); Mensink, R.P.; Schwab, U

    2016-01-01

    Limiting the saturated fatty acid (SAFA) consumption forms the basis of dietary fat recommendations for heart health, despite several meta-analyses demonstrating no link be- tween dietary SAFA and the risk of cardiovascular disease (CVD). Three experts on dietary fat and health discussed the evidence of reducing SAFA intake at a symposium of the Federation of European Nutrition Societies in Berlin, Germany, October 23, 2015. Ronald P. Mensink, Maastricht University, the Netherlands, discussed...

  18. Combating Acid Deposition and Climate Change: Priorities for Asia

    McDonald, A.

    1999-01-01

    The article addresses two interactions relevant to acid rain and global warming. First are interactions between sulfur and carbon emissions in producing important impacts, e.g., agricultural impacts in Asia. Second are behavioral interactions, i.e., rational responses to policies targeting one problem that make the other more difficult to solve. Initial calculations for the case of no new policies to limit sulfur or carbon emissions suggest that the cooling effect of sulfate aerosols wou...

  19. Changes in fatty acid branching and unsaturation of Streptomyces griseus and Brevibacterium fermentans as a response to growth temperature.

    Suutari, M; Laakso, S

    1992-01-01

    Streptomyces griseus showed three different modes of changing fatty acids in response to temperature change. In Brevibacterium fermentans, two such responses were found. The responses involved changes in fatty acid branching, unsaturation, or chain length, depending on growth temperature range. Changes in unsaturation of branched-chain acids were characteristic at low growth temperatures.

  20. Present trends in HVDC converter station design

    Carlsson, Lennart; Asplund, Gunnar; Bjorklund, Hans; Flisberg, Gunnar [ABB Power Systems AB, Ludvika (Sweden)

    1994-12-31

    HVDC converter station technology has developed rapidly to satisfy increasing requirements during past 10 - 15 years, but there has not been any dramatic changes since thyristor valves were introduced in the mid 70s. This paper describes some recent and expected future developments, that will substantiality change and simplify future converter stations. (author) 4 refs., 7 figs.

  1. Wavelength converter technology

    Kloch, Allan; Hansen, Peter Bukhave; Poulsen, Henrik Nørskov;

    1999-01-01

    Wavelength conversion is important since it ensures full flexibility of the WDM network layer. Progress in optical wavelength converter technology is reviewed with emphasis on air-optical wavelength converter types based on semiconductor optical amplifiers....

  2. Increasing of Reliability of Converter

    Trebuňa, F.

    2006-01-01

    Full Text Available The innovative activities in steel production invoke exploitation of new machines with the higher production capacity and productivity of labor. The paper deals with deformation and stress analysis of carrying parts of converter pedestal on the base of which the proposals and supporting measures were made that had the aim to increase reliability of the converter during steel production. This was achieved by lifespan prolongation of anchor and connecting bolts of converter pedestal, by change of stiffness of connected elements as well as by correction of nuts of bolted connections. The realization of structural changes decreased loading amplitudes and consequently the vibrations of pedestal. Solution was verified by numerical and experimental procedures of mechanics.

  3. Phase change material: Optimizing the thermal properties and thermal conductivity of myristic acid/palmitic acid eutectic mixture with acid-based surfactants

    In this study the addition of surfactant to fatty acids as phase change materials (PCMs) for solar thermal applications is proposed. The incorporation of surfactant additives into a eutectic mixture of fatty acids can significantly increase the value of latent heat storage and can suppress undercooling. We report the preparation of myristic acid/palmitic acid (MA/PA) eutectic mixture as Phase Change Material (PCM) with addition of 0, 5, 10, 15, and 20% sodium myristate (SM), sodium palmitate (SP), and sodium stearate (SS), the influence of surfactant additives on thermal properties and thermal conductivity of eutectic mixtures. It was found that the addition of 5% SM, 5% SP, and 5% SS to MA/PA eutectic mixture is very effective in depressing the liquid/solid phase change temperature, reducing the undercooling and increasing the amount of latent heat of fusion as well as thermal conductivity of eutectic PCM compared to eutectic PCM without surfactants. Furthermore MA/PA + 5%SS has the highest latent heat of fusion of 191.85 J g−1, while MA/PA + 5%SM showed the least undercooling of 0.34 °C and the highest thermal conductivity of 0.242 W m−1 K−1. -- Highlights: • Myristic acid (MA) and palmitic acid (PA) are fatty acids component. • The eutectic composition ratio of MA/PA obtained at 70/30, wt.%. • 5% each acid-based surfactants were reduces the melting and undercooling temperature of MA/PA (70/30, wt.%). • Thermal conductivity and ΔHf of MA/PA (70/30, wt.%) were increased by adding 5% surfactants. • MA/PA + 5% acid-based surfactants have a great potential to apply in LHTES applications

  4. Wavelength converter technology

    Kloch, Allan; Hansen, Peter Bukhave; Poulsen, Henrik Nørskov; Wolfson, David; Jepsen, Kim Stokholm; Clausen, Anders; Limal, Emmanuel; Buxens, Alvaro A.

    Wavelength conversion is important since it ensures full flexibility of the WDM network layer. Progress in optical wavelength converter technology is reviewed with emphasis on air-optical wavelength converter types based on semiconductor optical amplifiers.......Wavelength conversion is important since it ensures full flexibility of the WDM network layer. Progress in optical wavelength converter technology is reviewed with emphasis on air-optical wavelength converter types based on semiconductor optical amplifiers....

  5. Impact of climate changes and correlations on oil fatty acids in sunflower

    Sunflower oil is a major important vegetable oil because it is widely used in human nutrition and in many industrial productions depends on fatty acid composition. Field studies were conducted during in two years on the same soil to investigate changes of climate induced oil fatty acid composition of a traditional sunflower, and to obtain correlations among oil fatty acids. Seed oil content and twelve fatty acid percentages of sunflower oil were analyzed. Variations for years were significant for seed oil content and palmitic acid (C16:0), oleic (C18:1), linoleic (C18:2), linolenic (C18:3), miristic (C14:0) and eicosenoic acids (C20:1). Higher temperatures during seed development in 2010 resulted with 68.38 % increasing in oleic content of the traditional sunflower hybrid. The highest negative correlations (r= -0.99) were noted between oleic and linoleic acids. (author)

  6. Converting accounts receivable into cash.

    Folk, M D; Roest, P R

    1995-09-01

    In recent years, increasing numbers of healthcare providers have converted their accounts receivable into cash through a process called securitization. This practice has gained popularity because it provides a means to raise capital necessary to healthcare organizations. Although securitization transactions can be complex, they may provide increased financial flexibility to providers as they prepare for continuing change in the healthcare industry. PMID:10145096

  7. Adipose tissue fatty acid patterns and changes in anthropometry: a cohort study.

    Christina Catherine Dahm

    Full Text Available INTRODUCTION: Diets rich in n-3 long chain polyunsaturated fatty acids (LC-PUFA, but low in n-6 LC-PUFA and 18:1 trans-fatty acids (TFA, may lower the risk of overweight and obesity. These fatty acids have often been investigated individually. We explored associations between global patterns in adipose tissue fatty acids and changes in anthropometry. METHODS: 34 fatty acid species from adipose tissue biopsies were determined in a random sample of 1100 men and women from a Danish cohort study. We used sex-specific principal component analysis and multiple linear regression to investigate the associations of adipose tissue fatty acid patterns with changes in weight, waist circumference (WC, and WC controlled for changes in body mass index (WC(BMI, adjusting for confounders. RESULTS: 7 principal components were extracted for each sex, explaining 77.6% and 78.3% of fatty acid variation in men and women, respectively. Fatty acid patterns with high levels of TFA tended to be positively associated with changes in weight and WC for both sexes. Patterns with high levels of n-6 LC-PUFA tended to be negatively associated with changes in weight and WC in men, and positively associated in women. Associations with patterns with high levels of n-3 LC-PUFA were dependent on the context of the rest of the fatty acid pattern. CONCLUSIONS: Adipose tissue fatty acid patterns with high levels of TFA may be linked to weight gain, but patterns with high n-3 LC-PUFA did not appear to be linked to weight loss. Associations depended on characteristics of the rest of the pattern.

  8. Step changes and deactivation behaviour in the continuous decarboxylation of stearic acid

    Madsen, Anders Theilgaard; Rozmyslowicz, B.; Simakova, I.;

    2011-01-01

    Deoxygenation of dilute and concentrated stearic acid over 2% Pd/C beads was performed in a continuous reactor at 300 degrees C and 20 bar pressure of Ar or 5% H-2/Ar. Stable operation was obtained in 5% H-2 atmosphere, with 95% conversion of 10 mol % dilute stearic acid in dodecane and 12......% conversion of pure stearic acid. Deactivation took place in H-2-deficient gas atmosphere, probably as a result of the formation of unsaturated products and coking in the pore system. Transient experiments with step changes were performed: 1 h was required for the step change to be visible in liquid sampling...

  9. Step Changes and Deactivation Behavior in the Continuous Decarboxylation of Stearic Acid

    Madsen, Anders Theilgaard; Rozmysłowicz, Bartosz; Simakova, Irina L.;

    2011-01-01

    Deoxygenation of dilute and concentrated stearic acid over 2% Pd/C beads was performed in a continuous reactor at 300 °C and 20 bar pressure of Ar or 5% H2/Ar. Stable operation was obtained in 5% H2 atmosphere, with 95% conversion of 10 mol % dilute stearic acid in dodecane and 12% conversion of...... pure stearic acid. Deactivation took place in H2-deficient gas atmosphere, probably as a result of the formation of unsaturated products and coking in the pore system. Transient experiments with step changes were performed: 1 h was required for the step change to be visible in liquid sampling, whereas...

  10. Changes in soil organic carbon and total nitrogen in croplands converted to walnut-based agroforestry systems and orchards in southeastern Loess Plateau of China.

    Lu, Sen; Meng, Ping; Zhang, Jinsong; Yin, Changjun; Sun, Shiyou

    2015-11-01

    Limited information is available on the effects of agroforestry system practices on soil properties in the Loess Plateau of China. Over the last decade, a vegetation restoration project has been conducted in this area by converting cropland into tree-based agroforestry systems and orchards to combat soil erosion and degradation. The objective of the present study was to determine the effects of land use conversion on soil organic carbon and total nitrogen in southeastern Loess Plateau. The experiment included three treatments: walnut intercropping system (AF), walnut orchard (WO), and traditional cropland (CR). After 7 years of continual management, soil samples were collected at 0-10, 10-30, and 30-50-cm depths for three treatments, and soil organic carbon (SOC) and total nitrogen (TN) were measured. Results showed that compared with the CR and AF treatments, WO treatment decreased both SOC and TN concentrations in the 0-50-cm soil profile. However, similar patterns of SOC and TN concentrations were observed in the AF and CR treatments across the entire profile. The SOC stocks at 0-50-cm depth were 5.42, 5.52, and 4.67 kg m(-2) for CR, AF, and WO treatments, respectively. The calculated TN stocks at 0-50-cm depth were 0.63, 0.62, and 0.57 kg m(-2) for CR, AF, and WO treatments, respectively. This result demonstrated that the stocks of SOC and TN in WO were clearly lower than those of AF and CR and that the walnut-based agroforestry system was more beneficial than walnut monoculture in terms of SOC and TN sequestration. Owing to the short-term intercropping practice, the changes in SOC and TN stocks were slight in AF compared with those in CR. However, a significant decrease in SOC and TN stocks was observed during the conversion of cropland to walnut orchard after 7 years of management. We also found that land use types had no significant effect on soil C/N ratio. These findings demonstrated that intercropping between walnut rows can potentially maintain

  11. Structural Changes of Oil Palm Empty Fruit Bunch (OPEFB after Fungal and Phosphoric Acid Pretreatment

    Mohammad J. Taherzadeh

    2012-12-01

    Full Text Available Oil palm empty fruit bunch (OPEFB was pretreated using white-rot fungus Pleurotus floridanus, phosphoric acid or their combination, and the results were evaluated based on the biomass components, and its structural and morphological changes. The carbohydrate losses after fungal, phosphoric acid, and fungal followed by phosphoric acid pretreatments were 7.89%, 35.65%, and 33.77%, respectively. The pretreatments changed the hydrogen bonds of cellulose and linkages between lignin and carbohydrate, which is associated with crystallinity of cellulose of OPEFB. Lateral Order Index (LOI of OPEFB with no pretreatment, with fungal, phosphoric acid, and fungal followed by phosphoric acid pretreatments were 2.77, 1.42, 0.67, and 0.60, respectively. Phosphoric acid pretreatment showed morphological changes of OPEFB, indicated by the damage of fibre structure into smaller particle size. The fungal-, phosphoric acid-, and fungal followed by phosphoric acid pretreatments have improved the digestibility of OPEFB’s cellulose by 4, 6.3, and 7.4 folds, respectively.

  12. Structural changes of oil palm empty fruit bunch (OPEFB) after fungal and phosphoric acid pretreatment.

    Isroi; Ishola, Mofoluwake M; Millati, Ria; Syamsiah, Siti; Cahyanto, Muhammad N; Niklasson, Claes; Taherzadeh, Mohammad J

    2012-01-01

    Oil palm empty fruit bunch (OPEFB) was pretreated using white-rot fungus Pleurotus floridanus, phosphoric acid or their combination, and the results were evaluated based on the biomass components, and its structural and morphological changes. The carbohydrate losses after fungal, phosphoric acid, and fungal followed by phosphoric acid pretreatments were 7.89%, 35.65%, and 33.77%, respectively. The pretreatments changed the hydrogen bonds of cellulose and linkages between lignin and carbohydrate, which is associated with crystallinity of cellulose of OPEFB. Lateral Order Index (LOI) of OPEFB with no pretreatment, with fungal, phosphoric acid, and fungal followed by phosphoric acid pretreatments were 2.77, 1.42, 0.67, and 0.60, respectively. Phosphoric acid pretreatment showed morphological changes of OPEFB, indicated by the damage of fibre structure into smaller particle size. The fungal-, phosphoric acid-, and fungal followed by phosphoric acid pretreatments have improved the digestibility of OPEFB's cellulose by 4, 6.3, and 7.4 folds, respectively. PMID:23247371

  13. Viscosity changes in hyaluronic acid: Irradiation and rheological studies

    Daar, Eman [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)], E-mail: e.daar@surrey.ac.uk; King, L.; Nisbet, A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Thorpe, R.B. [Fluids and Systems Centre, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Bradley, D.A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2010-04-15

    Hyaluronic acid (HA) is a significant component of the extracellular matrix (ECM), particular interest being shown herein in synovial fluid. The present study aims to investigate the degrading effects of X-ray radiation on HA at radiotherapy doses. Measurements of viscosity and shear stresses on HA solutions have been made at different shear rates using various types of viscometer for different concentrations in the range 0.01-1% w/v of HA. The HA has been subjected to doses of 6 MV photon radiation ranging from 0 to 20 Gy, the major emphasis being on doses below 5 Gy. It is found that there is a dose-dependent relationship between viscosity and shear rate, viscosity reducing with radiation dose, this being related to polymer scissions via the action of radiation-induced free radicals. The dependency appears to become weaker at higher concentrations, possibly due to the contribution to viscosity from polymer entanglement becoming dominant over that from mean molecular weight. Present results, for HA solutions in the concentration range 0.01% to 1% w/v, show reduced viscosity with dose over the range 0-4 Gy, the latter covering the dose regime of interest in fractionated radiotherapy. The work also shows agreement with previous Raman microspectrometry findings by others, the possible bond alterations being defined by comparison with available published data.

  14. Viscosity changes in hyaluronic acid: Irradiation and rheological studies

    Hyaluronic acid (HA) is a significant component of the extracellular matrix (ECM), particular interest being shown herein in synovial fluid. The present study aims to investigate the degrading effects of X-ray radiation on HA at radiotherapy doses. Measurements of viscosity and shear stresses on HA solutions have been made at different shear rates using various types of viscometer for different concentrations in the range 0.01-1% w/v of HA. The HA has been subjected to doses of 6 MV photon radiation ranging from 0 to 20 Gy, the major emphasis being on doses below 5 Gy. It is found that there is a dose-dependent relationship between viscosity and shear rate, viscosity reducing with radiation dose, this being related to polymer scissions via the action of radiation-induced free radicals. The dependency appears to become weaker at higher concentrations, possibly due to the contribution to viscosity from polymer entanglement becoming dominant over that from mean molecular weight. Present results, for HA solutions in the concentration range 0.01% to 1% w/v, show reduced viscosity with dose over the range 0-4 Gy, the latter covering the dose regime of interest in fractionated radiotherapy. The work also shows agreement with previous Raman microspectrometry findings by others, the possible bond alterations being defined by comparison with available published data.

  15. Viscosity changes in hyaluronic acid: irradiation and rheological studies

    Full text: Hyaluronic acid (HA) is a significant component of the extracellular matrix (ECM) and synovial fluid. Measurements of viscosity and shear stresses at different shear rates are made with rotational viscometers on HA solutions of different concentrations (0.01% - 1% wbv) subjected to doses of 6 MV photon radiation ranging from 0 - 15 Gy. It is found that there is a dose-dependent relationship between viscosity and shear rate, viscosity reducing with radiation dose, this being related to polymer scissions via the action of radiation-induced free radicals. The dependency appears to become weaker at higher concentrations, possibly due to the contribution to viscosity from polymer entanglement becoming dominant over that from mean molecular weight. HA rheology is also found to be adequately described by a power law equation over the shear rate range 0 - 1000 s-1, where the consistency factor K2 = 3.497 ± 0.151 Pa.sn and n = 0.524 ± 0.015

  16. Aqueous Phase Photo-Oxidation of Succinic Acid: Changes in Hygroscopic Properties and Reaction Products

    Hudson, P. K.; Ninokawa, A.; Hofstra, J.; de Lijser, P.

    2013-12-01

    Atmospheric aerosol particles have been identified as important factors in understanding climate change. The extent to which aerosols affect climate is determined, in part, by hygroscopic properties which can change as a result of atmospheric processing. Dicarboxylic acids, components of atmospheric aerosol, have a wide range of hygroscopic properties and can undergo oxidation and photolysis reactions in the atmosphere. In this study, the hygroscopic properties of succinic acid aerosol, a non-hygroscopic four carbon dicarboxylic acid, were measured with a humidified tandem differential mobility analyzer (HTDMA) and compared to reaction products resulting from the aqueous phase photo-oxidation reaction of hydrogen peroxide and succinic acid. Reaction products were determined and quantified using gas chromatography-flame ionization detection (GC-FID) and GC-mass spectrometry (GC-MS) as a function of hydrogen peroxide:succinic acid concentration ratio and photolysis time. Although reaction products include larger non-hygroscopic dicarboxylic acids (e.g. adipic acid) and smaller hygroscopic dicarboxylic acids (e.g. malonic and oxalic acids), comparison of hygroscopic growth curves to Zdanovskii-Stokes-Robinson (ZSR) predictions suggests that the hygroscopic properties of many of the product mixtures are largely independent of the hygroscopicity of the individual components. This study provides a framework for future investigations to fully understand and predict the role of chemical reactions in altering atmospheric conditions that affect climate.

  17. Changes in some physicochemical properties and fatty acid composition of irradiated meatballs during storage

    Meatball samples were irradiated using a 60Co irradiation source (with the dose of 1, 3, 5 and 7 kGy) and stored (1, 2 and 3 weeks at 4 °C) to appraise some physicochemical properties and the fatty acid composition. The physicochemical results showed no significant differences in moisture, protein, fat and ash content of meatballs because of irradiation. However, total acidity, peroxide and thiobarbituric acid (TBA) values increased significantly as a result of irradiation doses and storage period. The fatty acid profile in meatball samples changed with irradiation. While saturated fatty acids (C16:0, C17:0, C18:0, and C20:0) increased with irradiation, monounsaturated (C14:1, C15:1, C18:1, and C20:1) and polyunsaturated (C18:2, C18:3, and C22:2) fatty acids decreased with irradiation. Trans fatty acids (C16:1trans, C18:1trans, C18:2trans, C18:3trans) increased with increasing irradiation doses. Meatball samples irradiated at 7 kGy had the highest total trans fatty acid content. This research shows that some physicochemical properties and fatty acid composition of meatballs can be changed by gamma irradiation. (author)

  18. The solubility of aluminum in acidic forest soils: Long-term changes due to acid deposition

    Mulder, Jan; Stein, Alfred

    1994-01-01

    Despite the ecological and pedogenic importance of Al, its solubility control in acidic forest soils is poorly understood. Here we discuss the solubility of Al and its development with time in three acid brown forest soils in The Netherlands, which are under extreme acidification from atmospheric deposition. All soil solutions (to a 60 cm depth) were undersaturated with respect to synthetic gibbsite (Al(OH) 3; log K = 9.12 at 8°C), with the highest degree of undersaturation occurring in the surface soil. In about one third of the individual soil layers a significant positive correlation existed between the activity of Al 3+ and H +, but this relationship was far less than cubic. Kinetically constrained dissolution of Al is unlikely to explain the disequilibrium with respect to gibbsite, because undersaturation was highest through summer when water residence times were longest and temperatures greatest. Time series analysis of six year data sets for several soil layers revealed a significant annual decline in soil solution pH and Al solubility (defined as log Al + 3 pH) despite a constant concentration of strong acid anions. The annual decline of both pH and Al solubility was greatest in the surface soil and was positively correlated with the relative depletion of reactive organically bound soil Al. The results support our earlier hypothesis that in strongly acidified forest soils complexation by solid phase organics controls the solubility of Al even in mineral soil layers, relatively low in organic C. The data lend no support to the current widespread and often uncritical use of gibbsite as a model for the Al solubility in highly acidic forest soils (pH temperate zone.

  19. Determination of Vitamin C and Organic Acid Changes in Strawberry by HPLC During Cold Storage

    Mehmet Ali KOYUNCU

    2010-12-01

    Full Text Available High pressure liquid chromatographic (HPLC methods were used for measurement of vitamin C and organic acid changes of two strawberry cultivars (‘Dorit’ and ‘Selva’ during cold storage. Harvested strawberries at the last stage of commercial ripeness were placed in perforated (8 perforations, 10 mm diameter plastic boxes and stored at 0°C temperature and 90-95% relative humidity for 10 days. Vitamin C content decreased in both cultivars but no significant differences were found in ‘Dorit’ from the beginning to the end of the storage. The highest share of total acids was contributed by citric acid. It decreased with increase in storage time in both cultivars. Malic acid content of cultivars also decreased with storage time. Tartaric, oxalic and fumaric acid contents fluctuated during storage, but at the end of cold storage these organic acids had decreased in comparison to initial values.

  20. Three-phase AC-AC power converters based on matrix converter topology matrix-reactance frequency converters concept

    Szczesniak, Pawel

    2013-01-01

    AC voltage frequency changes is one of the most important functions of solid state power converters. The most desirable features in frequency converters are the ability to generate load voltages with arbitrary amplitude and frequency, sinusoidal currents and voltages waveforms; the possibility of providing unity power factor for any load; and, finally, a simple and compact power circuit. Over the past decades, a number of different frequency converter topologies have appeared in the literature, but only the converters with either a voltage or current DC link are commonly used in industrial app

  1. ITER convertible blanket evaluation

    Proposed International Thermonuclear Experimental Reactor (ITER) convertible blankets were reviewed. Key design difficulties were identified. A new particle filter concept is introduced and key performance parameters estimated. Results show that this particle filter concept can satisfy all of the convertible blanket design requirements except the generic issue of Be blanket lifetime. If the convertible blanket is an acceptable approach for ITER operation, this particle filter option should be a strong candidate

  2. The photoelectric displacement converter

    Dragoner, Valeriu V.

    2005-02-01

    In the article are examined questions of constructing photoelectric displacement converter satisfying demands that are stated above. Converter has channels of approximate and precise readings. The approximate reading may be accomplished either by the method of reading from a code mask or by the method of the consecutive calculation of optical scale gaps number. Phase interpolator of mouar strips" gaps is determined as a precise measuring. It is shown mathematical model of converter that allow evaluating errors and operating speed of conversion.

  3. Short communication: Measuring the angiotensin-converting enzyme inhibitory activity of an 8-amino acid (8mer) fragment of the C12 antihypertensive peptide.

    Paul, Moushumi; Phillips, John G; Renye, John A

    2016-05-01

    An 8-AA (8mer) fragment (PFPEVFGK) of a known antihypertensive peptide derived from bovine αS1-casein (C12 antihypertensive peptide) was synthesized by microwave-assisted solid-phase peptide synthesis and purified by reverse phase HPLC. Its ability to inhibit angiotensin-converting enzyme (ACE) was assessed and compared with that of the parent 12mer peptide (FFVAPFPEVFGK) to determine the effect of truncating the sequence on overall hypotensive activity. The activity of the truncated 8mer peptide was found to be almost 1.5 times less active than that of the 12mer, with ACE-inhibiting IC50 (half-maximal inhibitory concentration) values of 108 and 69μM, for the 8mer and 12mer, respectively. Although the 8mer peptide is less active than the original 12mer peptide, its overall activity is comparable to activities reported for other small proteins that elicit physiological responses within humans. These results suggest that microbial degradation of the 12mer peptide would not result in a complete loss of antihypertensive activity if used to supplement fermented foods and that the stable 8mer peptide could have potential as a blood pressure-lowering agent for use in functional foods. PMID:26971162

  4. Analysis of free amino acids in green coffee beans. II. Changes of the amino acid content in arabica coffees in connection with post-harvest model treatment.

    Arnold, U; Ludwig, E

    1996-10-01

    To investigate amino acid changes in green coffee beans in the post-harvest period, amino acid concentrations were determined in green beans and after modelled drying, fermentation and storage. After the drying at alternating temperatures up to maximally 40 degrees C, considerable changes in the concentrations of individual amino acids were identified. At the beginning of the storage period, significant changes in concentration were found to a minor extent. Under the condition of drying, it was mainly the concentration of glutamic acid that changed considerably. There was an increase in all the samples by 500 mg/kg dry matter on average, which corresponds to an increase of about 50% of the original value. In contrast, the concentration of aspartic acid in most of the samples decreased clearly due to drying. For the predominant part of the coffee samples, there was a significant increase in the hydrophobic amino acids Val, Phe, Ile and Leu. Changes of the quantities of other amino acids were non-uniform and only insignificant. Constant drying at 80 degrees C for most of the amino acids brought about only minor concentration changes compared to those values obtained at 40 degrees C. Modelled fermentation had no significant effect on the concentrations of the individual amino acids. After a 4-week storage of dried beans, amino acid concentrations did not change further. It is very possible that different post-harvest treatment parameters may influence the amount of aroma precursor compounds in the coffee beans. PMID:9123976

  5. Assessment of morphological changes and DNA quantification: An in vitro study on acid-immersed teeth

    K Sowmya

    2013-01-01

    Full Text Available Context: Acid immersion of victim′s body is one of the methods employed to subvert identification of the victim, and hence of the perpetrator. Being hardest and chemically the most stable tissue in the body, teeth can be an important forensic investigative medium in both living and nonliving populations. Teeth are also good reservoirs of both cellular and mitochondrial DNA; however, the quality and quantity of DNA obtained varies according to the environment the tooth has been subjected to. DNA extraction from acid-treated teeth has seldom been reported. Aims: The objectives of the present study were to assess the morphological changes along with DNA recovery from acid-immersed teeth. Materials and Methods: Concentrated hydrochloric acid, nitric acid, and sulfuric acid were employed for tooth decalcification. DNA was extracted on an hourly basis using phenol-chloroform method. Quantification of extracted DNA was done using a spectrophotometer. Results: Results showed that hydrochloric acid had more destructive capacity compared to other acids. Conclusion: Sufficient quantity of DNA was obtainable till the first 2 hours of acid immersion and there was an inverse proportional relation between mean absorbance ratio and quantity of obtained DNA on an hourly basis.

  6. Sialic acid changes in Dalton's lymphoma-bearing mice after cyclophosphamide and cisplatin treatment

    Nicol B.M.

    2002-01-01

    Full Text Available Sialic acid changes in Dalton's lymphoma cells and other tissues of 10-12-week-old Swiss albino mice were investigated in relation to tumour growth in vivo and following cyclophosphamide (ip, 200 mg/kg body weight or cisplatin (ip, 8 mg/kg body weight treatment. Three to four animals of both sexes were used in each experimental group. The sialic acid level of tumour cells (0.88 µmol/g increased with tumour progression (1.44-1.59 µmol/g; P<=0.05 in mice. Sialic acid concentration in other tissues (liver, kidney, testes and brain also increased (~40, 10, 30 and 58%, respectively in the tumour-bearing hosts as compared with that in the respective tissues of normal mice. In vivo cyclophosphamide or cisplatin treatment resulted in an overall decrease of sialic acid contents in the tissues. Cyclophosphamide was more efficient in lowering tissue sialic acid than cisplatin (P<=0.01, ANOVA. It is suggested that sialic acid residues could be an important factor contributing to the manifestation of malignant properties in cancer cells in general and Dalton's lymphoma cells in particular. A significant decrease in the sialic acid content of Dalton's lymphoma cells after cisplatin or cyclophosphamide treatment may bring about specific changes in tumour cells which could be associated with tumour regression.

  7. Changes of gastrointestinal myoelectric activity and bile acid pool size after cholecystectomy in guinea pigs

    Xue-Mei Zhang; Lei Dong; Li-Na Liu; Bi-Xia Chang; Qian He; Qian Li

    2005-01-01

    AIM: To investigate the bile acid pool size after cholecystectomy whether or not correlated to the gastrointestinal migrating myoelectric complex (MMC) in guinea pigs.METHODS: Gallbladder motilities were assessed before cholecystectomy. Furthermore, we continuously monitored interdigestive gastrointestinal motilities using bipolar electrodes in conscious guinea pigs before and after surgery at 4 wk in standard diet group and high cholesterol diet (cholesterol gallstone) group. Total bile acid pool sizes were measured by isotope dilution method at meantime.RESULTS: After cholecystectomy, there were parallel falls in duration of phase Ⅰ, Ⅱ, Ⅲ and MMC cycle duration but increase in amplitude in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones. However, There were not significantly differences. On the other hand, the bile acid pool was definitely small in the GS guinea pigs compared to normal guinea pigs and became slightly smaller after cholecystectomy. Similarly, bile acid in gallbladder bile, fecal bile acid was slightly increased in GS guinea pigs after cholecystectomy, to the same degree as normal. These differences, however, were not significant.CONCLUSION: It is concluded that in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones: (1) Cholecystectomy produce a similar but less marked trend in bile acid pool; and (2) MMC are linked to enterohepatic circulation of bile acids, rather than surgery, which is consistent with changes of the bile acid pool size. As a result, gastrointestinal dyskinesia is not involved in occurrence of postcholecystectomy syndrome.

  8. Plasma Phospholipid Long-Chain n-3 Polyunsaturated Fatty Acids and Body Weight Change

    Jakobsen, Marianne U; Dethlefsen, Claus; Due, Karen M;

    2011-01-01

    We investigated the association between the proportion of long-chain n-3 polyunsaturated fatty acids (PUFA) in plasma phospholipids from blood samples drawn at enrollment and subsequent change in body weight. Sex, age, and BMI were considered as potential effect modifiers.......We investigated the association between the proportion of long-chain n-3 polyunsaturated fatty acids (PUFA) in plasma phospholipids from blood samples drawn at enrollment and subsequent change in body weight. Sex, age, and BMI were considered as potential effect modifiers....

  9. Investigating temporal changes in the yeast phosphoproteome upon fatty acid starvation

    Pultz, Dennis; Bennetzen, Martin; Andersen, Jens S.;

    2011-01-01

    Investigating stemporal changes in the yeast phosphoproteome upon fatty acid starvation Dennis Pultz*, Martin Bennetzen*, Jens S. Andersen and Nils J.Færgeman. Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark, 5230 Reducing food intake to induce...... changes in the phosphoproteome coupling fatty acid starvation to autophagy and starvation related cellular responses in general. By use of this approach we have identified approximately 2000 phosphorylation sites of which more than 400 have been identified as being regulated. Here, we present results...

  10. Resonant Demagnetization PWM Forward Converter

    BİLGİN, Bülent

    2003-01-01

    In this paper, a new approach to demagnetization process of a PWM forward converter (FC) is proposed. According to this approach, the demagnetization winding and diode of a conventional FC are removed, and an external capacitor is added in parallel with the secondary diode. This replacement changes the linear demagnetization process of a conventional FC into a resonant demagnetization process. The theoretical performance results of the proposed resonant demagnetization forward conve...

  11. Changes of organic acid exudation and rhizosphere pH in rice plants under chromium stress

    The effect of chromium (Cr) stress on the changes of rhizosphere pH, organic acid exudation, and Cr accumulation in plants was studied using two rice genotypes differing in grain Cr accumulation. The results showed that rhizosphere pH increased with increasing level of Cr in the culture solution and with an extended time of Cr exposure. Among the six organic acids examined in this experiment, oxalic and malic acid contents were relatively higher, and had a significant positive correlation with the rhizosphere pH, indicating that they play an important role in changing rhizosphere pH. The Cr content in roots was significantly higher than that in stems and leaves. Cr accumulation in plants was significantly and positively correlated with rhizosphere pH, and the exudation of oxalic, malic and citric acids, suggesting that an increase in rhizosphere pH, and exudation of oxalic, malic and citric acid enhances Cr accumulation in rice plants. - Rhizosphere pH and organic acid exudation of rice roots are markedly affected by chromium level in culture solution

  12. Dietary ascorbic acid and subsequent change in body weight and waist circumference

    Larsen, Sofus C; Angquist, Lars; Ahluwalia, Tarunveer Singh;

    2014-01-01

    BACKGROUND: Cross-sectional data suggests that a low level of plasma ascorbic acid positively associates with both Body Mass Index (BMI) and Waist Circumference (WC). This leads to questions about a possible relationship between dietary intake of ascorbic acid and subsequent changes in anthropome......BACKGROUND: Cross-sectional data suggests that a low level of plasma ascorbic acid positively associates with both Body Mass Index (BMI) and Waist Circumference (WC). This leads to questions about a possible relationship between dietary intake of ascorbic acid and subsequent changes in...... anthropometry, and whether such associations may depend on genetic predisposition to obesity. Hence, we examined whether dietary ascorbic acid, possibly in interaction with the genetic predisposition to a high BMI, WC or waist-hip ratio adjusted for BMI (WHR), associates with subsequent annual changes in weight...... (∆BW) and waist circumference (∆WC). METHODS: A total of 7,569 participants' from MONICA, the Diet Cancer and Health study and the INTER99 study were included in the study. We combined 50 obesity associated single nucleotide polymorphisms (SNPs) in four genetic scores: a score of all SNPs and a score...

  13. Converting Transaldolase into Aldolase through Swapping of the Multifunctional Acid-Base Catalyst: Common and Divergent Catalytic Principles in F6P Aldolase and Transaldolase.

    Sautner, Viktor; Friedrich, Mascha Miriam; Lehwess-Litzmann, Anja; Tittmann, Kai

    2015-07-28

    Transaldolase (TAL) and fructose-6-phosphate aldolase (FSA) both belong to the class I aldolase family and share a high degree of structural similarity and sequence identity. The molecular basis of the different reaction specificities (transferase vs aldolase) has remained enigmatic. A notable difference between the active sites is the presence of either a TAL-specific Glu (Gln in FSA) or a FSA-specific Tyr (Phe in TAL). Both residues seem to have analoguous multifunctional catalytic roles but are positioned at different faces of the substrate locale. We have engineered a TAL double variant (Glu to Gln and Phe to Tyr) with an active site resembling that of FSA. This variant indeed exhibits aldolase activity as its main activity with a catalytic efficiency even larger than that of authentic FSA, while TAL activity is greatly impaired. Structural analysis of this variant in complex with the dihydroxyacetone Schiff base formed upon substrate cleavage identifies the introduced Tyr (genuine in FSA) to catalyze protonation of the central carbanion-enamine intermediate as a key determinant of the aldolase reaction. Our studies pinpoint that the Glu in TAL and the Tyr in FSA, although located at different positions at the active site, similarly act as bona fide acid-base catalysts in numerous catalytic steps, including substrate binding, dehydration of the carbinolamine, and substrate cleavage. We propose that the different spatial positions of the multifunctional Glu in TAL and of the corresponding multifunctional Tyr in FSA relative to the substrate locale are critically controlling reaction specificity through either unfavorable (TAL) or favorable (FSA) geometry of proton transfer onto the common carbanion-enamine intermediate. The presence of both potential acid-base residues, Glu and Tyr, in the active site of TAL has deleterious effects on substrate binding and cleavage, most likely resulting from a differently organized H-bonding network. Large-scale motions of the

  14. Changes of the Anthocyanins and Antioxidant properties of Concord Grape (Vitis labrusca Pomace After Acid Hydrolysis

    Mustafa Bener

    2016-05-01

    Full Text Available Grape pomace contains high levels of valuable antioxidants such as anthocyanins and phenolic compounds that help prevent chronic diseases such as cardiovascular problems and cancers. In this study, Concord grape pomace was soaked in acidic solutions at different time intervals and pHs in a water bath at 80 oC. Five kinds of anthocyanins were released and identified in the pomace after acid hydrolysis. The releasing rate of anthocyanins and antioxidant activities of the acid hydrolyzed pomace extracts were determined by multitest systems. Different antioxidant assays including total antioxidant capacity (TAC, total phenolic content (TPC and free radical scavenging activity (RSA were used to evaluate the antioxidant properties of the acid hydrolyzed pomace extracts. The change in antioxidant capacity of the pomace extracts during hydrolysis was correlated with total phenolic content and free radical scavenging activity but had little relationship with anthocyanin contents.

  15. Impact of anticipated climate change on recovery from acidification of an acid-sensitive forested catchment

    Hruška, Jakub; Lamačová, Anna; Oulehle, Filip; Krám, Pavel; Farda, Aleš; Chuman, Tomáš

    Volume 1. 1. Brno: Global Change Research Centre, Academy of Sciences of the Czech Republic, v. v. i, 2015 - (Urban, O.; Klem, K.), s. 150-162 ISBN 978-80-87902-14-1 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : climate change * acid-sensitive forested * stream- water chemistry * forest management Subject RIV: EH - Ecology, Behaviour

  16. Changing corporate culture within the European lead/acid battery industry

    Recent economic and political factors have had a strong influence on the lead/acid battery industry in both West and East Europe. Since the publication in 1989 by Batteries International and the Lead Development Association of a map of European battery factories, the number of battery companies has declined. By 1992, a significant shift had taken place in the share of the lead/acid battery market in Europe with the result that a few companies came to influence a major proportion of battery production and sales. The reasons for this relatively fast structural change are examined. Under the pressure from continuing internal and external forces, likely outcomes for battery business in Europe are proposed as the lead/acid industry changes to meet new challenges. (orig.)

  17. Improving Power Converter Reliability

    Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon;

    2014-01-01

    is measured in a wind power converter at a low fundamental frequency. To illustrate more, the test method as well as the performance of the measurement circuit are also presented. This measurement is also useful to indicate failure mechanisms such as bond wire lift-off and solder layer degradation......The real-time junction temperature monitoring of a high-power insulated-gate bipolar transistor (IGBT) module is important to increase the overall reliability of power converters for industrial applications. This article proposes a new method to measure the on-state collector?emitter voltage of a...... high-power IGBT module during converter operation, which may play a vital role in improving the reliability of the power converters. The measured voltage is used to estimate the module average junction temperature of the high and low-voltage side of a half-bridge IGBT separately in every fundamental...

  18. Converting Nonclassicality into Entanglement.

    Killoran, N; Steinhoff, F E S; Plenio, M B

    2016-02-26

    Quantum mechanics exhibits a wide range of nonclassical features, of which entanglement in multipartite systems takes a central place. In several specific settings, it is well known that nonclassicality (e.g., squeezing, spin squeezing, coherence) can be converted into entanglement. In this work, we present a general framework, based on superposition, for structurally connecting and converting nonclassicality to entanglement. In addition to capturing the previously known results, this framework also allows us to uncover new entanglement convertibility theorems in two broad scenarios, one which is discrete and one which is continuous. In the discrete setting, the classical states can be any finite linearly independent set. For the continuous setting, the pertinent classical states are "symmetric coherent states," connected with symmetric representations of the group SU(K). These results generalize and link convertibility properties from the resource theory of coherence, spin coherent states, and optical coherent states, while also revealing important connections between local and nonlocal pictures of nonclassicality. PMID:26967398

  19. EVALUATING CHANGES IN FOREST CONDITION POTENTIALLY RELATED TO ACIDIC DEPOSITION: AN EXAMPLE USING RED SPRUCE

    As a result of concern about forest decline in Europe and the USA, research has been conducted to investigate changes in forest condition that might be associated with acidic deposition and related pollutants (principally ozone). ymptoms of tree decline observed in the field typi...

  20. Topical retinoic acid changes the epidermal cell surface glycosylation pattern towards that of a mucosal epithelium

    Griffiths, C E; Dabelsteen, Erik; Voorhees, J J

    1996-01-01

    Topical all-trans retinoic acid (RA) produces a number of epidermal changes which are indistinguishable from those observed following treatment with a local irritant, namely sodium lauryl sulphate (SLS). This observation has led to criticism that the efficacy of RA in disorders such as photoageing...

  1. Change in the plasmid copy number in acetic acid bacteria in response to growth phase and acetic acid concentration.

    Akasaka, Naoki; Astuti, Wiwik; Ishii, Yuri; Hidese, Ryota; Sakoda, Hisao; Fujiwara, Shinsuke

    2015-06-01

    Plasmids pGE1 (2.5 kb), pGE2 (7.2 kb), and pGE3 (5.5 kb) were isolated from Gluconacetobacter europaeus KGMA0119, and sequence analyses revealed they harbored 3, 8, and 4 genes, respectively. Plasmid copy numbers (PCNs) were determined by real-time quantitative PCR at different stages of bacterial growth. When KGMA0119 was cultured in medium containing 0.4% ethanol and 0.5% acetic acid, PCN of pGE1 increased from 7 copies/genome in the logarithmic phase to a maximum of 12 copies/genome at the beginning of the stationary phase, before decreasing to 4 copies/genome in the late stationary phase. PCNs for pGE2 and pGE3 were maintained at 1-3 copies/genome during all phases of growth. Under a higher concentration of ethanol (3.2%) the PCN for pGE1 was slightly lower in all the growth stages, and those of pGE2 and pGE3 were unchanged. In the presence of 1.0% acetic acid, PCNs were higher for pGE1 (10 copies/genome) and pGE3 (6 copies/genome) during the logarithmic phase. Numbers for pGE2 did not change, indicating that pGE1 and pGE3 increase their PCNs in response to acetic acid. Plasmids pBE2 and pBE3 were constructed by ligating linearized pGE2 and pGE3 into pBR322. Both plasmids were replicable in Escherichia coli, Acetobacter pasteurianus and G. europaeus, highlighting their suitability as vectors for acetic acid bacteria. PMID:25575969

  2. Radio-isotope converter

    Due to the surface power density required for thermoelectric and thermionic converters, available radioactive sources are surveyed and listed. Curves of specific minimum diameter versus thermal flux density are given. 210Po and 242Cm appear to be suitable for direct thermionic when alpha emitters such as 238Pu and 244Cm are still suitable for thermoelectric conversion. This mode will also work with beta emitters 170Tm, 90Sr, 144Ce and 137Cs. Some thermoelectric radioisotope heated converters are suggested. (authors)

  3. Thermionic photovoltaic energy converter

    Chubb, D. L. (Inventor)

    1985-01-01

    A thermionic photovoltaic energy conversion device comprises a thermionic diode mounted within a hollow tubular photovoltaic converter. The thermionic diode maintains a cesium discharge for producing excited atoms that emit line radiation in the wavelength region of 850 nm to 890 nm. The photovoltaic converter is a silicon or gallium arsenide photovoltaic cell having bandgap energies in this same wavelength region for optimum cell efficiency.

  4. Changes in the phenolic acid content during wort boiling and whirlpool

    Dominik Szwajgier

    2011-03-01

    Full Text Available Background. Phenolic acids were repeatedly pointed out as powerful antioxidants. The studies in the past prove the differences in the phenolic acids content in malts and worts. In this work, the influence of wort boiling and whirlpool separation on the phenolic acid content was studied. Material and methods. Worts were produced in the local brewery by the infusion method using pale pilsner-type barley malt. Samples were analysed at the beginning of the boil, after the boil and after whirlpool separation (5 and 30 min. Free and total alkali extractable phenolic acids contents were analysed using HPLC-DAD. Results. The main phenolic acid in all worts was ferulic acid in the free (35.47 ±3.28-117.51 ±4.40 mg·dm-3 as well as total alkali extractable form (193.49 ±4.84-294.72 ±2.65 mg·dm-3. With both forms no decrease was seen after boiling of wort (80 min at 100-100.5°C followed by wort separation in the whirlpool. Similarly, no significant changes in the free and total form of p-coumaric acid content were seen. Conclusions. It can be concluded that an elevated temperature during wort boiling and separation in whirlpool had no significant influence on the content of phenolic acids (at least in the case of the specific mashing program applied in this brewery: equipment, enzyme preparations, mashing, time-temperature parameters etc.. The differences in the phenolic acids levels could be rather attributed to different supplies of malt used for the production.

  5. Study of ZrO2 nanopowders based stearic acid phase change materials

    Desheng Ai; Lizan Su; Zhe Gao; Changsheng Deng; Xiaming Dai

    2010-01-01

    ZrO2 nanopowders based stearic acid phase change materials(PCMs)were prepared by high-energy milling.The concept of heat capacity factor(HCF)was used to analyze the thermal properties of the materials.The heat storage property of PCMs,containing the same content of stearic acid(23% by mass)in the starting materials but synthesized by different technical processes,was investigated by using HCF.It was found that there were vast influences of different dispersants on the heat capacity.The samples prepared with chloroform provided the best heat storage ability in all samples tested.

  6. Changes in composition of sapropelic organic acid A and S bitumens from Lake Lakheper in relation to depth of origin

    Bondar' , Ye.; Palu, V.; Veski, R.

    1982-01-01

    Test results are presented for acid bitumens (from A and S sapropelic post-glacier lake (Lakheper) in Estonian SSR). Using liquid gas chromatography and chromato-mass spectrometry normally saturated and unsaturated monocarbonic acids were determined (figures provided), as well as iso- and antiiso-monocarbonic acids, oxycarbonic, and cyclopropane acids (formulas provided). Analysis of derived data makes it possible to assume that changes in bitumen acids at early stages of diagenesis of the sapropelic mud is determined not only by diagenesis itself, but by changes in conditions under which sedimentation occurred.

  7. Changes in Erucic Acid Concentration of Rape Seeds in Advanced Generations

    Selim Aytaç Şahin Gizlenci Mustafa Acar

    2006-01-01

    Full Text Available This study was carried out to determine the extend of changes in erucic acid concentration of rapeseeds which were grown in Carsamba and Bafra Plains of Central Blacksea Region. In addition to field experiments, the same experiment was conducted in the greenhouse to avoid polen transfer from other sources. The first material used was 00 type rapeseed cultivars. In order to ensure a good result, the experiment sites were selected based on the intensity of other Brassica species (B. oleracea, B. rapa, B. nigra. The harvested rape seeds was the seed material of following year. Erucic acid content was measured for seeds obtained each year. The erucic acid content for three genarations showed that it was much lower than the limits for health (0.04 %.

  8. Amino acid and protein changes in tilapia and spanish mackerel after irradiation and storage

    Some amino acids in tilapia decreased while some others increased when subjected to doses up to 10.0 kGy. However, 10 kGy contributed to a significant reduction in all amino acids of Spanish mackerel. Variations in amino acid contents continued during post-irradiation storage with no consistent trend of increase or decrease. SDS-PAGE of protein from both fish showed 27 bands of subunits with MW < 14.0-94.0 KD. Isoelectric focusing patterns of sarcoplasmic protein of unirradiated and irradiated fish showed no charge in the number of bands, while some changes were observed in the intensities of the anodic and cathodic bands depending on isoelectric points (pIs)

  9. SSG Wave Energy Converter

    Margheritini, Lucia; Vicinanza, Diego; Frigaard, Peter

    2008-01-01

    The SSG (Sea Slot-cone Generator) is a wave energy converter of the overtopping type. The structure consists of a number of reservoirs one on the top of each others above the mean water level, in which the water of incoming waves is stored temporary. In each reservoir, expressively designed low...... head hydroturbines are converting the potential energy of the stored water into power. A key to success for the SSG will be the low cost of the structure and its robustness. The construction of the pilot plant is scheduled and this paper aims to describe the concept of the SSG wave energy converter and...... the studies behind the process that leads to its construction. The pilot plant is an on-shore full scale module in 3 levels with an expected power production of 320 MWh/y in the North Sea. Location, wave climate and laboratory tests results will be used here to describe the pilot plant and its...

  10. Study on preparation and thermal property of binary fatty acid and the binary fatty acids/diatomite composite phase change materials

    This study prepared a series of binary phase change materials by mixing decanoic acid, dodecanoic acid, hexadecanoic acid and octadecanoic acid each other. The phase-transition temperature of binary fatty acid and its corresponding mixing proportion are calculated with phase diagram thermodynamic method. The results are verified by the experimental result of the heat absorption curve and the Differential Scanning Calorimetry (DSC) analysis curve. The results show that the calculation method of phase diagram thermodynamic calculation can be taken as a basis for mixing proportion of binary fatty acid phase change materials. In addition, the decanoic-dodecanoic acid/diatomite composite phase change material (PCM) are prepared and its microstructure, thermal property and thermal reliability are characterized. The result shows that the decanoic-dodecanoic acid is uniformly adsorbed into diatomite and the form-stable PCM are formed. The phase-transition temperature and the latent heat of the decanoic-dodecanoic acid/diatomite composite PCMs is 16.74 oC and 66.8114 J/g, respectively.

  11. Design of Monolithic Integrator for Strain-to-Frequency Converter

    Tuan Mohd. Khairi Tuan Mat; Chew Sue Ping; Akram Abdul Azid

    2012-01-01

    Strain-to-Frequency converter (SFC) is a one of the analog conditioner tools that converts any strain signal to the frequency signal. The basic concept of SFC is by detecting any changing of strains, then converting the strain to the voltage signal and converting the voltage signal to the frequency signal. This tool consists of 3 main  components which are strain gauge, differential integrator and comparator. This paper presents the designing and analysis of monolithic integrator that to be u...

  12. Modeling the impacts of temperature and precipitation changes on soil CO2 fluxes from a Switchgrass stand recently converted from cropland.

    Lai, Liming; Kumar, Sandeep; Chintala, Rajesh; Owens, Vance N; Clay, David; Schumacher, Joseph; Nizami, Abdul-Sattar; Lee, Sang Soo; Rafique, Rashad

    2016-05-01

    Switchgrass (Panicum virgatum L.) is a perennial C4 grass native to North America and successfully adapted to diverse environmental conditions. It offers the potential to reduce soil surface carbon dioxide (CO2) fluxes and mitigate climate change. However, information on how these CO2 fluxes respond to changing climate is still lacking. In this study, CO2 fluxes were monitored continuously from 2011 through 2014 using high frequency measurements from Switchgrass land seeded in 2008 on an experimental site that has been previously used for soybean (Glycine max L.) in South Dakota, USA. DAYCENT, a process-based model, was used to simulate CO2 fluxes. An improved methodology CPTE [Combining Parameter estimation (PEST) with "Trial and Error" method] was used to calibrate DAYCENT. The calibrated DAYCENT model was used for simulating future CO2 emissions based on different climate change scenarios. This study showed that: (i) the measured soil CO2 fluxes from Switchgrass land were higher for 2012 which was a drought year, and these fluxes when simulated using DAYCENT for long-term (2015-2070) provided a pattern of polynomial curve; (ii) the simulated CO2 fluxes provided different patterns with temperature and precipitation changes in a long-term, (iii) the future CO2 fluxes from Switchgrass land under different changing climate scenarios were not significantly different, therefore, it can be concluded that Switchgrass grown for longer durations could reduce changes in CO2 fluxes from soil as a result of temperature and precipitation changes to some extent. PMID:27155405

  13. Angiotensin-converting enzyme

    Sørensen, P G; Rømer, F K; Cortes, D

    1984-01-01

    In order to evaluate bleomycin-associated lung damage in humans, lung function parameters and serum levels of the endothelial-bound angiotensin-converting enzyme (ACE) were determined by serial measurements in 11 patients who were treated for testicular cancer. None developed clinical or radiolog......In order to evaluate bleomycin-associated lung damage in humans, lung function parameters and serum levels of the endothelial-bound angiotensin-converting enzyme (ACE) were determined by serial measurements in 11 patients who were treated for testicular cancer. None developed clinical or...

  14. Effects of changes in acid base and calcium concentration on fasting serum insulin, proinsulin, and glucose concentrations.

    Smellie, W S; O'Donnell, J; Davidson, H.; Couper, J; Logue, F. C.

    1994-01-01

    AIMS--To test the hypothesis that alterations in acid base or calcium concentration may affect proinsulin processing or the insulin secretion mechanism. METHODS--Changes in proinsulin secretion or cleavage were assessed by measuring serum intact proinsulin and immunoreactive insulin concentrations in three models of acid base and calcium disturbance: (1) subacute changes in acid base status in six volunteers who received oral placebo, ammonium chloride, or sodium bicarbonate for three five da...

  15. Developmental changes in aspartate-family amino acid biosynthesis in pea chloroplasts

    Isolated chloroplasts are known to synthesize the asp-derived amino acids (ile, hse, lys and thr) from [14C]asp (Mills et al, 1980, Plant Physiol. 65, 1166). Now, we have studied the influence of tissue age on essential amino acid biosynthesis in pea (Pisum sativum) plastids. Chloroplasts from the younger (third and fourth) leaves of 12 day old plants, were 2-3 times more active in synthesizing lys and thr from [14C]asp than those from older (first or second) leaves. We also examined two key pathway enzymes (aspartate kinase and homoserine dehydrogenase); with each enzyme,a activity in younger leaves was about 2 times that in plastids from older tissue. Both lys- and thr-sensitive forms of aspartate kinase are known in plants; in agreement with earlier work, we found that lys-sensitive activity was about 4 times higher in the younger tissues, while the thr-sensitive activity changed little during development (Davies and Miflin, 1977, Plant Sci. Lett. 9, 323). Recently the role of aspartate kinase and homoserine dehydrogenase in controlling asp-family amino acid synthesis has been questioned (Giovanelli et al, 1989, Plant Physiol. 90, 1584); we hope that measurements of amino acid levels in chloroplasts as well as further enzyme studies will help us to better understand the regulation of asp-family amino acid synthesis

  16. Alkali- or acid-induced changes in structure, moisture absorption ability and deacetylating reaction of β-chitin extracted from jumbo squid (Dosidicus gigas) pens.

    Jung, Jooyeoun; Zhao, Yanyun

    2014-01-01

    Alkali- or acid-induced structural modifications in β-chitin from squid (Dosidicus gigas, d'Orbigny, 1835) pens and their moisture absorption ability (MAA) and deacetylating reaction were investigated and compared with α-chitin from shrimp shells. β-Chitin was converted into the α-form after 3h in 40% NaOH or 1-3 h in 40% HCl solution, and α-chitin obtained from NaOH treatment had higher MAA than had native α-chitin, due to polymorphic destructions. In contrast, induced α-chitin from acid treatment of β-chitin had few polymorphic modifications, showing no significant change (P>0.05) in MAA. β-Chitin was more susceptible to alkali deacetylation than was α-chitin, and required a lower concentration of NaOH and shorter reaction time. These results demonstrate that alkali- or acid-treated β-chitin retained high susceptibility toward solvents, which in turn resulted in good biological activity of β-chitosan for use as a natural antioxidant and antimicrobial substance or application as edible coatings and films for various food applications. PMID:24444948

  17. Changes in body composition in broilers by a sulfur amino acid deficiency during growth

    Conde Aguilera, Jose Alberto; Cobo Ortega, Carlos; Tesseraud, Sophie; LESSIRE, Michel; Mercier, Yves; Van Milgen, Jacob

    2013-01-01

    In the factorial approach, amino acid (AA) requirements are determined using the AA composition of retained protein, which is assumed to be constant. However, this hypothesis may not be valid because the AA composition of body protein can be affected by the diet. The objective of this study was to quantify the changes in chemical body composition of broilers receiving diets either deficient (TSAA–) or sufficient (TSAA+) in TSAA. Diet TSAA+ was formulated according to the Ross recommendation. ...

  18. Effect of lignin content on changes occurring in poplar cellulose ultrastructure during dilute acid pretreatment

    Sun, Qining; Foston, Marcus; Meng, Xianzhi; Sawada, Daisuke; Pingali, Sai Venkatesh; O’Neill, Hugh M; Li, Hongjia; Wyman, Charles E; Langan, Paul; Art J. Ragauskas; Kumar, Rajeev

    2014-01-01

    Background Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic deconstruction is critical to the continued growth of renewable biofuel production. A key step in bioethanol production is thermochemical pretreatment to reduce plant cell wall recalcitrance for downstream processes. Previous studies of dilute acid pretreatment (DAP) have shown significant changes in cellulose ultrastructure that occur during pretreatment, but there is still a substantial kn...

  19. Optical State-of-Change Monitor for Lead-Acid Batteries

    Weiss, Jonathan D.

    1998-07-24

    A method and apparatus for determining the instantaneous state-of-charge of a battery in which change in composition with discharge manifests itself as a change in optical absorption. In a lead-acid battery, the sensor comprises a fiber optic system with an absorption cdl or, alternatively, an optical fiber woven into an absorbed-glass-mat battery. In a lithium-ion battery, the sensor comprises fiber optics for introducing light into the anode to monitor absorption when lithium ions are introduced.

  20. Age-related changes in kynurenic acid production in rat brain

    Gramsbergen, J B; Schmidt, W; Turski, W A;

    1992-01-01

    months of age in all five brain regions examined. No changes were observed in the liver. The changes were particularly pronounced in the cortex and in the striatum where enzyme activity increased three-fold during the period studied. KYNA production from its bioprecursor L-kynurenine was also......-dependent increase of KYNA concentration in brain tissue, suggest an enhanced KYNA tone in the aged brain. Together with the reported decline in cerebral excitatory amino acid receptor densities with age, increased production of KYNA may play a role in cognitive and memory dysfunction in old animals....

  1. Age-related changes in retinoic, docosahexaenoic and arachidonic acid modulation in nuclear lipid metabolism.

    Gaveglio, Virginia L; Pascual, Ana C; Giusto, Norma M; Pasquaré, Susana J

    2016-08-15

    The aim of this work was to study how age-related changes could modify several enzymatic activities that regulate lipid mediator levels in nuclei from rat cerebellum and how these changes are modulated by all-trans retinoic acid (RA), docosahexaenoic acid (DHA) and arachidonic acid (AA). The higher phosphatidate phosphohydrolase activity and lower diacylglycerol lipase (DAGL) activity observed in aged animals compared with adults could augment diacylglycerol (DAG) availability in the former. Additionally, monoacylglycerol (MAG) availability could be high due to an increase in lysophosphatidate phosphohydrolase (LPAPase) activity and a decrease in monocylglycerol lipase activity. Interestingly, RA, DHA and AA were observed to modulate these enzymatic activities and this modulation was found to change in aged rats. In adult nuclei, whereas RA led to high DAG and MAG production through inhibition of their hydrolytic enzymes, DHA and AA promoted high MAG production by LPAPase and DAGL stimulation. In contrast, in aged nuclei RA caused high MAG generation whereas DHA and AA diminished it through LPAPase activity modulation. These results demonstrate that aging promotes a different nuclear lipid metabolism as well as a different type of non-genomic regulation by RA, DHA and AA, which could be involved in nuclear signaling events. PMID:27355428

  2. Conformational Changes in Thiazole-2-carboxylic Acid Selectively Induced by Excitation with Narrowband Near-IR and UV Light.

    Halasa, Anna; Reva, Igor; Lapinski, Leszek; Nowak, Maciej J; Fausto, Rui

    2016-04-01

    Conformers and photoinduced conformational transformations were studied for monomers of thiazole-2-carboxylic acid (TCA). The matrix-isolation technique and excitations with narrowband near-IR and UV light, tuned in an optical parametric oscillator, were used for this purpose. Form I, with the carboxylic moiety in the trans orientation and with the hydrogen atom of the OH group directed toward the nitrogen atom of the ring, was the most abundant in low-temperature argon or nitrogen matrixes. Conformer II, differing from I by 180° rotation of the OH group around the C-O bond, was also trapped in the matrixes, but in much smaller amount. The abundance of form II was experimentally determined as ∼6% of the total amount of TCA molecules. Selective excitation of I with narrowband near-IR laser light resulted in I → II transformation. This near-IR-induced conformational change was photoreversible: form II converted back to I upon selective excitation of II with near-IR light of different wavelength. Conformational conversions of I into II, or vice versa, were also induced in TCA monomers by narrowband UV excitations at 300 nm (for I → II transformation) and at 305 nm (for II → I transformation). A spontaneous conversion of photogenerated II into the most stable form I was observed for the compound trapped in the matrix at 15 K and kept in the dark. This process was very slow; the estimated half-life time of conformer II was longer than 50 h. Finally, TCA was shown to thermally decompose at room temperature, yielding CO2 and thiazole. PMID:26986193

  3. Digital to Analog Converter Description

    Tuijl, van, B.A.J.

    2003-01-01

    A circuit for analogue to digital or digital to analogue conversion comprising at least 2n matched current sources (40-1, 40-2, 40-n), where n is the resolution required of the conversion. Preferably more than 2n current sources (40-1, 40-2, 40-n) are used. The order in which the sources (40-1, 40-2, 40-n) are used may be changed in different samples. The current sources (40-1, 40-2, 40-n) may be replaced by one bit switched capacitor converters or by inverters connected to one end of a set o...

  4. An Electromagnetic Beam Converter

    2009-01-01

    The present invention relates to an electromagnetic beam converter and a method for conversion of an input beam of electromagnetic radiation having a bell shaped intensity profile a(x,y) into an output beam having a prescribed target intensity profile l(x',y') based on a further development of the...

  5. Definition of Power Converters

    Bordry, F

    2015-01-01

    The paper is intended to introduce power conversion principles and to define common terms in the domain. The concept s of sources and switches are defined and classified. From the basic laws of source interconnections, a generic method of power converter synthesis is presented. Some examples illustrate this systematic method. Finally, the commutation cell and soft commuta tion are introduced and discussedd.

  6. Convertible Proxy Signcryption Scheme

    李继国; 李建中; 曹珍富; 张亦辰

    2004-01-01

    In 1996, Mambo et al introduced the concept of proxy signature. However, proxy signature can only provide the delegated authenticity and cannot provide confidentiality. Recently, Gamage et al and Chan and Wei proposed different proxy signcryption schemes respectively, which extended the concept of proxy signature.However, only the specified receiver can decrypt and verify the validity of proxy signcryption in their schemes.To protect the receiver' s benefit in case of a later dispute, Wu and Hsu proposed a convertible authenticated encryption scheme, which carn enable the receiver to convert signature into an ordinary one that can be verified by anyone. Based on Wu and Hsu' s scheme and improved Kim' s scheme, we propose a convertible proxy signcryption scheme. The security of the proposed scheme is based on the intractability of reversing the one-way hash function and solving the discrete logarithm problem. The proposed scheme can satisfy all properties of strong proxy signature and withstand the public key substitution attack and does not use secure channel. In addition, the proposed scheme can be extended to convertible threshold proxy signcryption scheme.

  7. Advanced DC/DC converters

    Luo, Fang Lin

    2003-01-01

    INTRODUCTIONHistorical ReviewMultiple Quadrant ChoppersPump CircuitsDevelopment of DC/DC Conversion TechniqueCategorize Prototypes and DC/DC Converters Family TreeVOLTAGE-LIFT CONVERTERSIntroductionSeven Self-Lift ConvertersPositive Output Luo-ConvertersNegative Output Luo-ConvertersModified Positive Output Luo-Converters Double Output Luo-ConvertersPOSITIVE OUTPUT SUPER-LIFT LUO-CONVERTERS IntroductionMain SeriesAdditional SeriesEnhanced Series Re-Enhanced Series Multiple-Enhanced Series Summary of Positive Output

  8. Changes in acid-phosphate content in enamel mineral during porcine amelogenesis.

    Shimoda, S; Aoba, T; Moreno, E C

    1991-12-01

    The present study was undertaken to investigate changes in the acid-phosphate content of porcine enamel mineral during its development and to assess separately the HPO4(2-) pools in labile and stable forms. Enamel samples at the secretory and maturing stages of amelogenesis were obtained from the permanent incisors of five- to six-month-old slaughtered piglets. Human enamel from erupted, extracted teeth, synthetic hydroxyapatite, and carbonatoapatite containing acid phosphate were included as references. The acid-phosphate content of each sample was determined chemically through its pyrolytic conversion to pyrophosphate. The assessment of HPO4(2-) in labile forms was made by analysis of samples preequilibrated with solutions containing 3 mmol/L phosphate at pH11 (to de-protonate the HPO4(2-) species on crystal surfaces). The analytical results of porcine enamel samples showed that: (a) the outermost secretory (youngest) enamel contained the highest HPO4(2-), corresponding to about 16% of the total phosphate; (b) the acid-phosphate content decreased gradually to 10% in the inner (older) secretory and to 6% in the maturing tissue; (c) a substantial part of the HPO4(2-) in developing enamel tissue (50-60% of the HPO4(2-) for the secretory enamel) was in labile forms; and (d) the pool of the labile HPO4(2-) decreased with the growth of enamel mineral. In parallel studies with mature human enamel, it was ascertained that the total acid phosphate was only about 3% of the total phosphate, much lower than in developing porcine enamel, and that the labile pool of HPO4(2-) was also small, corresponding to about 15% of the total acid phosphate determined.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1774383

  9. Dynamic changes in cardiac fatty acid metabolism in the stunned human myocardium

    The chronological changes or mechanisms in cardiac fatty acid metabolism under clinical conditions of hypoxia and ischemia have not been fully elucidated. 123I-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) can be used with single photon emission computed tomography (SPECT) to evaluate myocardial fatty acid metabolism. We investigated chronological changes in energy metabolism in the stunned human myocardium by means of 123I-BMIPP myocardial SPECT. We conducted 123I-BMIPP myocardial SPECT in 10 patients with stunned myocardium during the acute, subacute and chronic phases after onset. The left ventricle was divided into 9 regions on SPECT, and the degree of abnormalities in each region was scored in four grades from normal (0) to defect (4). We also examined wash-out rates on BMIPP images. The scores on early BMIPP images in the acute, subacute and chronic phases were 5.6±1.8, 13.4±3.5 and 2.5±1.1, respectively, and the score was highest in the subacute phase (p<0.001). Similarly, scores on the late images were 2.3±1.7, 18.3±4.5 and 4.7±2.6, respectively, and highest in the subacute phase (p<0.001). The wash-out rates (normal: 18.2±2.1%) in the acute, subacute and chronic phases were 12.1±4.8%, 44.9±10.0% and 23.1±4.6%, respectively, with the value being lowest during the acute phase (p<0.05), and highest during the subacute phase (p<0.001). There results suggested that fatty acid metabolism in the stunned human myocardium changes dynamically over time. (author)

  10. Ontogenetic changes in digestive enzyme activities and the amino acid profile of starry flounder Platichthys stellatus

    Song, Zhidong; Wang, Jiying; Qiao, Hongjin; Li, Peiyu; Zhang, Limin; Xia, Bin

    2016-09-01

    Ontogenetic changes in digestive enzyme activities and the amino acid (AA) profile of starry flounder, Platichthys stellatus, were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements. Larvae were collected at the egg stage and 0, 2, 4, 7, 12, 17, 24 days after hatching (DAH) for analysis. Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH. Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH. Pepsin activity increased sharply beginning 17 DAH. Lipase activity increased significantly 4 DAH and increased progressively with larval growth. Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease. High free amino acid (FAA) content was detected in starry flounder eggs (110.72 mg/g dry weight). Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae. Most FAAs (except lysine and methionine) decreased >50% in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae. Changes in the protein amino acid (PAA) profile were much milder than those observed for FAAs. Most PAAs increased gradually during larval development, except lysine and phenylalanine. The percentages of free threonine, valine, isoleucine, and leucine decreased until the end of the trial, whereas the protein forms of these four AAs followed the opposite trend. A comparison of the essential AA composition of live food (rotifers, Artemia nauplii, and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA. These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food. Moreover, the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.

  11. Ontogenetic changes in digestive enzyme activities and the amino acid profile of starry flounder Platichthys stellatus

    Song, Zhidong; Wang, Jiying; Qiao, Hongjin; Li, Peiyu; Zhang, Limin; Xia, Bin

    2016-01-01

    Ontogenetic changes in digestive enzyme activities and the amino acid (AA) profile of starry flounder, Platichthys stellatus, were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements. Larvae were collected at the egg stage and 0, 2, 4, 7, 12, 17, 24 days after hatching (DAH) for analysis. Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH. Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH. Pepsin activity increased sharply beginning 17 DAH. Lipase activity increased significantly 4 DAH and increased progressively with larval growth. Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease. High free amino acid (FAA) content was detected in starry flounder eggs (110.72 mg/g dry weight). Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae. Most FAAs (except lysine and methionine) decreased >50% in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae. Changes in the protein amino acid (PAA) profile were much milder than those observed for FAAs. Most PAAs increased gradually during larval development, except lysine and phenylalanine. The percentages of free threonine, valine, isoleucine, and leucine decreased until the end of the trial, whereas the protein forms of these four AAs followed the opposite trend. A comparison of the essential AA composition of live food (rotifers, Artemia nauplii, and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA. These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food. Moreover, the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.

  12. Global gene expression changes in human urothelial cells exposed to low-level monomethylarsonous acid

    Highlights: ► Chronic exposure to 50 nM monomethylarsonous acid in UROtsa was investigated. ► At 3 months of exposure substantial changes were observed in gene expression. ► Notable changes occurred in mitogenic signaling, stress, immune and inflammatory responses. ► Gene expression changes correlate with phenotypic changes from previous studies. -- Abstract: Bladder cancer has been associated with chronic arsenic exposure. Monomethylarsonous acid [MMA(III)] is a metabolite of inorganic arsenic and has been shown to transform an immortalized urothelial cell line (UROtsa) at concentrations 20-fold less than arsenite. MMA(III) was used as a model arsenical to examine the mechanisms of arsenical-induced transformation of urothelium. A microarray analysis was performed to assess the transcriptional changes in UROtsa during the critical window of chronic 50 nM MMA(III) exposure that leads to transformation at 3 months of exposure. The analysis revealed only minor changes in gene expression at 1 and 2 months of exposure, contrasting with substantial changes observed at 3 months of exposure. The gene expression changes at 3 months were analyzed showing distinct alterations in biological processes and pathways such as a response to oxidative stress, enhanced cell proliferation, anti-apoptosis, MAPK signaling, as well as inflammation. Twelve genes selected as markers of these particular biological processes were used to validate the microarray and these genes showed a time-dependent changes at 1 and 2 months of exposure, with the most substantial changes occurring at 3 months of exposure. These results indicate that there is a strong association between the acquired phenotypic changes that occur with chronic MMA(III) exposure and the observed gene expression patterns that are indicative of a malignant transformation. Although the substantial changes that occur at 3 months of exposure may be a consequence of transformation, there are common occurrences of altered

  13. Ontogenetic change in the lipid and fatty acid composition of scleractinian coral larvae

    Figueiredo, J.; Baird, A. H.; Cohen, M. F.; Flot, J.-F.; Kamiki, T.; Meziane, T.; Tsuchiya, M.; Yamasaki, H.

    2012-06-01

    Some scleractinian coral larvae have an extraordinary capacity to delay metamorphosis, and this is reflected in the large geographic range of many species. Coral eggs typically contain a high proportion of wax esters, which have been hypothesized to provide a source of energy for long-distance dispersal. To better understand the role of lipids in the dispersal of broadcast spawning coral larvae, ontogenetic changes in the lipid and fatty acid composition of Goniastrea retiformis were measured from the eggs until larvae were 30 days old. Egg biomass was 78.8 ± 0.5% lipids, 86.3 ± 0.2% of which were wax esters, 9.3 ± 0.0% polar lipids, 4.1 ± 0.2% sterols, and 0.3 ± 0.1% triacylglycerols. The biomass of wax esters declined significantly through time, while polar lipids, sterols and triacylglycerols remained relatively constant, suggesting that wax esters are the prime source of energy for development. The most prevalent fatty acid in the eggs was palmitic acid, a marker of the dinoflagellate Symbiodinium, highlighting the importance of symbiosis in coral reproductive ecology. The proportion of polyunsaturated fatty acids declined through time, suggesting that they are essential for larval development. Interestingly, triacylglycerols are only abundant in the propagules that contain Symbiodinium, suggesting important differences in the energetic of dispersal among species with vertical and horizontal transmission of symbionts.

  14. Daily changes of amino acids in soybean leaflets are modified by CO2 enrichment

    Richard Charles Sicher

    2010-11-01

    Full Text Available The effects of CO2 enrichment on plant growth and on nitrogen partitioning were examined using soybean [Glycine max (L. Merr. cv. Clark] leaflets. Plants were grown from single seeds in matching controlled environment chambers. Continuous ambient CO2 partial pressures were from 38 to 40 Pa and elevated CO2 treatments were 68 to 70 Pa. Total above ground biomass, total leaf area and specific leaf weight of soybean were increased 78%, 58% and 33%, respectively, in response to CO2 enrichment when measured 25 days after sowing. Total chlorophyll (a+b was 25% greater in third trifoliolate soybean leaflets in response to CO2 enrichment but total soluble protein did not differ between treatments. These and other measurements indicated that soybean plants were nitrogen sufficient in this study. Variations of total soluble amino acids were observed in soybean leaflets and these were enhanced by CO2 enrichment when measurements were performed mid-day. However, concentrations of total amino acids were similar in both CO2 treatments by end of the photoperiod. Glycine was lower in the elevated compared to the ambient CO2 treatment suggesting that rates of photorespiration were diminished by elevated CO2. Alanine increased 20% in response to CO2 enrichment. Overall, changes of soluble amino acids in response to CO2 enrichment were smaller than in other crop species and a temporal shift occurred in the daily accumulation of amino acids in soybean leaflets.

  15. Assessing the costs and market impacts of carbon sequestration, climate change, and acid rain

    This thesis provides fourteen journal articles and papers. Thirteen of these papers were published in referred journals, covering environmental economics, policy modelling, policy analysis, and the physical sciences. One paper was published as a USDA Forest Service research report. The papers in the thesis are divided into three topical areas: 1) Section 2: The Economics of Carbon Sequestration. Eight papers plus Appendix A of the thesis cover the development and application of models to estimate the economic costs and management consequences of policies to sequester carbon emissions by planting trees on agricultural land in the US or through more intensive forest management. 2) Section 3: The Economics of Climate Change Damages. Two papers of the thesis cover the development of models that can be used to estimate the market and nonmarket damages associated with the impacts of climate change on water resources in the US. 3) Section 4: The Economics of Acid Rain Damages. Three papers in the thesis examine the methods that were developed to estimate the damages due to acid rain in the US by the National Acid Precipitation Assessment Program (NAPAP) and discuss more generally the role of economic policy analysis in this assessment. (EHS)

  16. Effect of folic acid on hematological changes in methionine-induced hyperhomocysteinemia in rats

    Ansari M

    2009-01-01

    Full Text Available The present study was designed to investigate the effect of folic acid on homocysteine, lipid profile and hematological changes in methionine-induced hyperhomocysteinemic rats. Hyperhomocysteinemia was induced by methionine (1 g/kg, p.o. administration for 30 days. Biochemical and hematological observations were further substantiated with histopathological examination. The increase in homocysteine, total cholesterol, low density lipoprotein-cholesterol, very low density lipoprotein-cholesterol and triglycerides levels with reduction in the levels of high density lipoprotein in serum were the salient features observed in methionine treated toxicologic control rats (i.e. group II. Hematological observations of the peripheral blood smears of toxicologic rats also showed crenation of red blood cells membrane and significant (P< 0.01 increase in total leukocyte count, differential leukocyte count and platelet counts with significant (P< 0.01 decrease in the mean hemoglobin levels, as compared to vehicle control rats. Administration of folic acid (100 mg/kg, p.o. for 30 days to methionine- induced hyperhomocysteinemic rats produced a significant (P< 0.01 decrease in the levels of homocysteine, total cholesterol, low density lipoprotein-cholesterol, very low density lipoprotein-cholesterol and triglycerides with significant (P< 0.01 increase in high density lipoprotein-cholesterol levels in serum when compared with toxicologic control rats. The present study, for the first time, investigates the effect of folic acid treatment on hematological changes in rats with methionine-induced hyperhomocysteinemia.

  17. Changes in Serum Free Amino Acids and Muscle Fatigue Experienced during a Half-Ironman Triathlon.

    Francisco Areces

    Full Text Available The aim of this study was to investigate the relationship between changes in serum free amino acids, muscle fatigue and exercise-induced muscle damage during a half-ironman triathlon. Twenty-six experienced triathletes (age = 37.0 ± 6.8 yr; experience = 7.4 ± 3.0 yr competed in a real half-ironman triathlon in which sector times and total race time were measured by means of chip timing. Before and after the race, a countermovement jump and a maximal isometric force test were performed, and blood samples were withdrawn to measure serum free amino acids concentrations, and serum creatine kinase levels as a blood marker of muscle damage. Total race time was 320 ± 37 min and jump height (-16.3 ± 15.2%, P 20%. However, neither the changes in serum free amino acids nor the tryptophan/BCAA ratio were related muscle fatigue or muscle damage during the race.

  18. A study on structural changes of amino acids implanted with low energy ions by FTIR spectroscopy

    The structural changes of aspartic acid (Asp) and phenylalanine (Phe) implanted with N+ ions of 30 keV were studied using Fourier transform infrared (FTIR) spectroscopy. Implanted at the same fluence of 1 x 1016/cm2, similar phenomena were observed in both Asp and Phe, i.e., the relative intensities of NH3+ vibration decreased and those of COO- stretching vibration increased. The changes of absorption intensities in Phe were more obvious than those in Asp. It was also observed that the intensities of COOH, COO- and NH3+ groups of Asp changed regularly with increasing implantation fluences. The possible reasons responsible for these results were studied. The radiolysis products of Asp implanted at a higher fluence of 6 x 1016/cm2 were analyzed

  19. Affecting Factors and Improving Measures for Converter Gas Recovery

    2007-01-01

    To change the undesirable present situation of recovering and using converter gas in steel plants in China,the basic approaches to improving the converter gas recovery rate were analyzed theoretically along with the change curves of the converter gas component content, based on the converter gas recovery system of Baosteel No. 2 steelmaking plant. The effects of converter device, raw material, air imbibed quantity, recovery restricted condition, and intensity of oxygen blowing on the converter gas recovery rate were studied. Among these, the effects of the air imbibed quantity, recovery restricted condition, and intensity of oxygen blowing are remarkable. Comprehensive measures were put forward for improving the converter gas recovery from the point of devices, etc. , and good results were achieved.

  20. Galvanically Isolated Modular Converter

    Christe, Alexandre; Dujic, Drazen

    2016-01-01

    Direct current (DC) electrical grids are already a reality in low voltage (LV) telecom distribution systems and point-to-point high voltage DC transmission. Medium voltage (MV) domain, despite its big potential, still suffers from a lack of suitable conversion and protection technologies. This study presents a bidirectional, galvanically isolated, high power converter for interface of emerging MVDC grids with readily available LVAC grids. To achieve high conversion efficiency, the integration...

  1. DSP controlled power converter

    Chan, CH; Pong, MH

    1995-01-01

    A digital controller is designed and implemented by a Digital Signal Processor (DSP) to replace the Pulse Width Modulator (PWM) and error amplifier compensation network in a two wheeler forward converter. The DSP controller is designed in three approaches: a) Discretization of analog controller - the design is based on the transfer function of the error amplifier compensation network. b) Digital PID controller design - the design is based on the general form of the pulse transfer function of ...

  2. Study on preparation, structure and thermal energy storage property of capric-palmitic acid/attapulgite composite phase change materials

    Highlights: → Capric-palmitic acid/attapulgite composite PCMs are prepared by vacuum method. → The composite PCMs is form-stable. → There is no chemical reaction between the capric-palmitic acid and attapulgite. → The phase change temperature and the latent heat of the composite PCM is 21.71 oC and 48.2 J/g, respectively. - Abstract: Fatty acid phase change materials (PCMs) have some advantages such as less corrosivity, no separation of subcooling phase and low price. In this paper, capric acid and palmitic acid are composited according to a certain mass ratio to prepare binary fatty acid. Capric-palmitic acid are absorbed into attapulgite by vacuum method to prepare capric-palmitic acid/attapulgite composite PCMs. Analysis methods such as differential scanning analysis (DSC), scanning electron microscope (SEM), Fourier transform infrared (FT-IR) and specific surface analysis (BET method) are used to test the thermal properties, structure and composition of the prepared composite PCM. The results indicate that the pore structure of the caplic-paltimic acid/attapulgite composite PCM is open-ended tubular capillary, which is beneficial to the adsorption. Capric acid and palmitic acid can be absorbed uniformly into attapulgite and the optimum absorption ratio of capric-palmitic binary fatty acid is 35%. There is no chemical reaction between the capric-palmitic acid and attapulgite. The phase change temperature of the capric-palmitic acid/attapulgite composite PCM is 21.71 oC and the latent heat is 48.2 J/g.

  3. EFFECT OF EXOGENOUS ABSCISIC ACID ON GROWTH AND BIOCHEMICAL CHANGES IN THE HALOPHYTE SUAEDA MARITIMA

    Anbarasi G.

    2015-04-01

    Full Text Available Different types of phytohormones are being extensively used to alleviate the adverse effect of salinity stress on plant growth. Among those, Abscisic acid (ABA is a plant stress hormone and one of the most important signaling molecules in plants. Drought and salinity activate De-novo abscisic acid synthesis prevent further water loss by evaporation through stomata, mediated by changes in the guard cell turgor pressure. Under osmotic stress abscisic acid induce the accumulation of protein involved in the biosynthesis of osmolites which increasing the stress tolerance of plant. In addition, exogenous application of ABA enhances the tolerance of plants or plant cells to cold, heat, drought, anoxia and heavy metal stresses. This study was carried out to study the exogenous abscisic (ABA acid induced regulatory role on the growth, water content, protein content, chlorophyll content, osmolyte accumulation and protein profiling through SDS PAGE in a halophyte, Suaeda maritima. The osmolyte accumulation of proline and glycine betaine was found to be more in 50 µM ABA concentrations. The protein profiling through SDS PAGE revealed that ̴ 66KDa proteins was not expressed in the control plant and in 10μM ABA treated plants. Interestingly, the ABA treatment induced a new protein of 14.2KDa in 10μM concentration. The ABA treated plants with concentrations 50μM, 100μM and 150μM showed changes in the expression of protein in abundance than the control and 10μM ABA treated plants. The findings in this study indicate that among all the concentrations, 50μM ABA concentration treated plants exhibited higher growth rate.

  4. Two phase interleaved buck converter for driving high power LEDs

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2011-01-01

    The goal of this paper is to evaluate an interleaved buck topology for driving high current light-emitting diodes. Low output capacitor value allows the use of non-electrolytic capacitors extending the lifetime of the converter. Converter is operated as a constant, regulated current source which...... increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can be...

  5. Leaching potential and changes in components of metals in two acidic ferrisols

    GUO Zhao-hui; LIAO Bo-han; HUANG Chang-yong

    2006-01-01

    Two acidic ferrisols, i.e., red soil (RS) and yellow red soil (YRS), from the vicinity regions of non-ferrous ores in Hunan province of China, were leached with simulated acid rain through artificial column experiments. The results show that the total leaching mass of metals are m(Zn)>m(Cu)>m(Cd) from the original soils and m(Cd)>m(Zn)>> m(Cu) from the contaminated soils with external metals after leaching for 60 d continuously, leaching quantities of Cd and Zn from the contaminated red soil (CRS)are more than that from the contaminated yellow red soil (CYRS), but for Cu, it is almost the same. The preferential fractions for leaching are mainly in exchangeable forms, and content of exchangeable forms decreases significantly in the contaminated soil profiles. The unstable fractions of Cd, Cu and Zn in the RS and YRS increase significantly with the decrease of pH value of simulated acid rain. Changes of fractions of external Cd, Cu, and Zn in the residual CRS and CYRS profiles are significantly affected by the acidity of acid rain, too. After leaching for 60 d continuously, Cd exists mostly in exchangeable form, Cu exists mainly in exchangeable, manganese oxide-occluded and organically bounding forms, and Zn exists in residual in CRS and CYRS profiles.Most of exchangeable Cd and Zn exist only small in surface layer (0-20 cm) and are transferred to the sub-layers, contrarily, Cu accumulates mostly in the topsoil (0-20 cm) with low translocation.

  6. Evening primrose oil in rheumatoid arthritis: changes in serum lipids and fatty acids.

    Jäntti, J; Nikkari, T.; Solakivi, T; Vapaatalo, H.; Isomäki, H

    1989-01-01

    The serum concentration of lipids and composition of fatty acids after overnight fasting were studied in 18 patients with rheumatoid arthritis treated for 12 weeks with either 20 ml of evening primrose oil containing 9% of gamma-linolenic acid or olive oil. The serum concentrations of oleic acid, eicosapentaenoic acid, and apolipoprotein B decreased and those of linoleic acid, gamma-linolenic acid, dihomo-gamma-linolenic acid, and arachidonic acid increased during treatment with evening primr...

  7. Changes in intramuscular amino acid levels in submaximally exercised horses - a pilot study.

    van den Hoven, R; Bauer, A; Hackl, S; Zickl, M; Spona, J; Zentek, J

    2010-08-01

    The time-dependent changes in intramuscular amino acid (AA) levels caused by exercise and by feeding a protein/AA supplement were analysed in nine horses. Horses were submitted to a total of four standardized exercise tests (SETs). Amino acid concentrations were determined prior to, immediately after, 4 and 18 h after exercise. The experiment was subdivided into two consecutive periods of 3 weeks. In each period two SETs were performed. In the second period, horses were given a protein/AA supplement within 1 h after exercise. Significant changes in mean plasma AA levels similar to previous studies were noted to be time-dependent and to be associated with feeding the supplement. The intramuscular concentrations of the free AA in relation to pre-exercise levels showed significant time-dependent changes for alanine, asparagine, aspartate, citrulline, glutamine, glycine, isoleucine, leucine, methionine, serine, taurine, threonine, tyrosine and valine. Feeding the supplement significantly increased the 4 h post-exercise intramuscular concentration of alanine, isoleucine, methionine and tyrosine. At 18 h after exercise, apart from isoleucine and methionine, levels were still increased and also those of asparagine, histidine and valine in relation to none treatment. Hence, it was concluded that AA mixtures administered orally to horses within 1 h after exercise increased intramuscular AA pool. PMID:19663973

  8. Seasonal changes in nitrogen-cycle gene abundances and in bacterial communities in acidic forest soils.

    Jung, Jaejoon; Yeom, Jinki; Han, Jiwon; Kim, Jisun; Park, Woojun

    2012-06-01

    The abundance of genes related to the nitrogen biogeochemical cycle and the microbial community in forest soils (bacteria, archaea, fungi) were quantitatively analyzed via real-time PCR using 11 sets of specific primers amplifying nifH, bacterial amoA, archaeal amoA, narG, nirS, nirK, norB, nosZ, bacterial 16S rRNA gene, archaeal 16S rRNA gene, and the ITS sequence of fungi. Soils were sampled from Bukhan Mountain from September of 2010 to July of 2011 (7 times). Bacteria were the predominant microbial community in all samples. However, the abundance of archaeal amoA was greater than bacterial amoA throughout the year. The abundances of nifH, nirS, nirK, and norB genes changed in a similar pattern, while narG and nosZ appeared in sensitive to the environmental changes. Clone libraries of bacterial 16S rRNA genes were constructed from summer and winter soil samples and these revealed that Acidobacteria was the most predominant phylum in acidic forest soil environments in both samples. Although a specific correlation of environmental factor and gene abundance was not verified by principle component analysis, our data suggested that the combination of biological, physical, and chemical characteristics of forest soils created distinct conditions favoring the nitrogen biogeochemical cycle and that bacterial communities in undisturbed acidic forest soils were quite stable during seasonal change. PMID:22752898

  9. The effect of esmolol on corrected-QT interval, corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients taking an angiotensin-converting enzyme inhibitor

    Zahit Çeker

    2015-02-01

    Full Text Available BACKGROUND AND OBJECTIVES: The importance of minimizing the exaggerated sympatho-adrenergic responses and QT interval and QT interval dispersion changes that may develop due to laryngoscopy and tracheal intubation during anesthesia induction in the hypertensive patients is clear. Esmolol decreases the hemodynamic response to laryngoscopy and intubation. However, the effect of esmolol in decreasing the prolonged QT interval and QT interval dispersion as induced by laryngoscopy and intubation is controversial. We investigated the effect of esmolol on the hemodynamic, and corrected-QT interval and corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients using angiotensin converting enzyme inhibitors. METHODS: 60 ASA I-II patients, with essential hypertension using angiotensin converting enzyme inhibitors were included in the study. The esmolol group received esmolol at a bolus dose of 500 mcg/kg followed by a 100 mcg/kg/min infusion which continued until the 4th min after intubation. The control group received 0.9% saline similar to the esmolol group. The mean blood pressure, heart rate values and the electrocardiogram records were obtained as baseline values before the anesthesia, 5 min after esmolol and saline administration, 3 min after the induction and 30 s, 2 min and 4 min after intubation. RESULTS: The corrected-QT interval was shorter in the esmolol group (p = 0.012, the corrected-QT interval dispersion interval was longer in the control group (p = 0.034 and the mean heart rate was higher in the control group (p = 0.022 30 s after intubation. The risk of arrhythmia frequency was higher in the control group in the 4-min period following intubation (p = 0.038. CONCLUSION: Endotracheal intubation was found to prolong corrected-QT interval and corrected-QT interval dispersion, and increase the heart rate during anesthesia induction with propofol in hypertensive patients using angiotensin converting

  10. Protective Effect of Ascorbic Acid on Molecular Behavior Changes of Hemoglobin Induced by Magnetic Field

    Hassan, Nahed S.; Abou Aiad, T. H. M.

    With the use of electricity and industrialization of societies, humans are commonly exposed to static magnetic field induced by electric currents. The putative mechanisms by which Static Magnetic Field (SMF) may affect biological systems is that of increasing free radical life span in organisms. To test this hypothesis, we investigate the effect of ascorbic acid (Vitamin C) treatment on the changes in the molecular behavior of hemoglobin as a result of exposure of the animals to magnetic field in the occupation levels. By measuring the relative permittivity, dielectric loss, relaxation time, conductivity, radius and diffusion coefficient of aqueous solutions of hemoglobin. These measurements were calculated in the frequency range of (100 Hz-100 kHz) to give more information about molecular behavior. Twenty four male albino rats were equally divided into four groups 1, 2, 3 and 4. Animals of group 1, were used as control, animals of group 2, were exposed to (0.2T) magnetic field and that of group 3, 4, were treated with Ascorbic Acid by two doses group 3 (20 mg kg-1 body weight), group 4 (50 mg kg-1 body weight) orally half hour before exposure to magnetic field. The sub chronic exposure expanded (1 h day-1) for 30 consecutive days. The results indicated that exposure of animals to magnetic field resulted in changes in the molecular behavior of hemoglobin molecule while treatment with ascorbic acid afforded comparatively more significant amelioration in these molecular changes, via decreasing the radical pair interaction of magnetic field with biological molecules.

  11. Convertible bond valuation focusing on Chinese convertible bond market

    Yang, Ke

    2010-01-01

    This paper mainly discusses the methods of valuation of convertible bonds in Chinese market. Different from common convertible bonds in European market, considering the complicate features of Chinese convertible bond, this paper represents specific pricing approaches for pricing convertible bonds with different provisions along with the increment of complexity of these provisions. More specifically, this paper represents the decomposing method and binomial tree method for pricing both of Non-...

  12. Effect of urine pH changed by dietary intervention on uric acid clearance mechanism of pH-dependent excretion of urinary uric acid

    Kanbara Aya

    2012-06-01

    food materials. Uric acid and excreted urine pH retained a linear relationship, as reported previously. Among the five factors which are associated with calculating clearances for both uric acid and creatinine, we identified a conspicuous difference between acidic and alkaline diets in the uric acid concentration in serum as well as in urine; uric acid in the serum was higher in the acidic group than in the alkaline group, while uric acid in the urine in the acidic group was lower than that in the alkaline group. These changes of uric acid in acidic urine and in serum were reflected in the reduction of its clearance. From these observations, it is considered that uric acid may be reabsorbed more actively in acidic urine than in alkaline urine. Conclusion We conclude that alkalization of urine by eating nutritionally well-designed alkaline -prone food is effective for removing uric acid from the body.

  13. Constitutive androstane receptor-mediated changes in bile acid composition contributes to hepatoprotection from lithocholic acid-induced liver injury in mice.

    Beilke, Lisa D; Aleksunes, Lauren M; Holland, Ricky D; Besselsen, David G; Beger, Rick D; Klaassen, Curtis D; Cherrington, Nathan J

    2009-05-01

    Pharmacological activation of the constitutive androstane receptor (CAR) protects the liver during cholestasis. The current study evaluates how activation of CAR influences genes involved in bile acid biosynthesis as a mechanism of hepatoprotection during bile acid-induced liver injury. CAR activators phenobarbital (PB) and 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) or corn oil (CO) were administered to C57BL/6 wild-type (WT) and CAR knockout (CAR-null) mice before and during induction of intrahepatic cholestasis using the secondary bile acid, lithocholic acid (LCA). In LCA-treated WT and all the CAR-null groups (excluding controls), histology revealed severe multifocal necrosis. This pathology was absent in WT mice pretreated with PB and TCPOBOP, indicating CAR-dependent hepatoprotection. Decreases in total hepatic bile acids and hepatic monohydroxy, dihydroxy, and trihydroxy bile acids in PB- and TCPOBOP-pretreated WT mice correlated with hepatoprotection. In comparison, concentrations of monohydroxylated and dihydroxylated bile acids were increased in all the treated CAR-null mice compared with CO controls. Along with several other enzymes (Cyp7b1, Cyp27a1, Cyp39a1), Cyp8b1 expression was increased in hepatoprotected mice, which could be suggestive of a shift in the bile acid biosynthesis pathway toward the formation of less toxic bile acids. In CAR-null mice, these changes in gene expression were not different among treatment groups. These results suggest CAR mediates a shift in bile acid biosynthesis toward the formation of less toxic bile acids, as well as a decrease in hepatic bile acid concentrations. We propose that these combined CAR-mediated effects may contribute to the hepatoprotection observed during LCA-induced liver injury. PMID:19196849

  14. Intake of ruminant trans fatty acids and changes in body weight and waist circumference

    Hansen, C P; Berentzen, T L; Halkjær, Jytte;

    2012-01-01

    Follow-up studies have suggested that total intake of trans fatty acids (TFA) is a risk factor for gain in body weight and waist circumference (WC). However, in a cross-sectional study individual TFA isomers in adipose tissue had divergent associations with anthropometry. Our objective was to inv...... investigate the association between intake of TFA from ruminant dairy and meat products and subsequent changes in weight and WC. Furthermore, potential effect modification by sex, age, body mass index and WC at baseline was investigated....

  15. Nitrogen isotopes in ice core nitrate linked to anthropogenic atmospheric acidity change

    Geng, Lei; Alexander, Becky; Cole-Dai, Jihong; Steig, Eric J.; Savarino, Joël; Sofen, Eric D.; Schauer, Andrew J.

    2014-01-01

    The specific cause of the long-term decrease in stable nitrogen isotope ratio (15N/14N) of ice core nitrate beginning ∼1850 is a subject of debate, hindering the efforts to understand changes in the global nitrogen cycle. Our high-resolution record of ice core 15N/14N combined with model calculations suggests that the decrease is mainly caused by equilibrium shift in gas−particle partitioning of atmospheric nitrate due to increasing atmospheric acidity resulting from anthropogenic emissions o...

  16. Plasma elaidic acid level as biomarker of industrial trans fatty acids and risk of weight change: report from the EPIC study.

    Véronique Chajès

    Full Text Available Few epidemiological studies have examined the association between dietary trans fatty acids and weight gain, and the evidence remains inconsistent. The main objective of the study was to investigate the prospective association between biomarker of industrial trans fatty acids and change in weight within the large study European Prospective Investigation into Cancer and Nutrition (EPIC cohort.Baseline plasma fatty acid concentrations were determined in a representative EPIC sample from the 23 participating EPIC centers. A total of 1,945 individuals were followed for a median of 4.9 years to monitor weight change. The association between elaidic acid level and percent change of weight was investigated using a multinomial logistic regression model, adjusted by length of follow-up, age, energy, alcohol, smoking status, physical activity, and region.In women, doubling elaidic acid was associated with a decreased risk of weight loss (odds ratio (OR = 0.69, 95% confidence interval (CI = 0.55-0.88, p = 0.002 and a trend was observed with an increased risk of weight gain during the 5-year follow-up (OR = 1.23, 95% CI = 0.97-1.56, p = 0.082 (p-trend<.0001. In men, a trend was observed for doubling elaidic acid level and risk of weight loss (OR = 0.82, 95% CI = 0.66-1.01, p = 0.062 while no significant association was found with risk of weight gain during the 5-year follow-up (OR = 1.08, 95% CI = 0.88-1.33, p = 0.454. No association was found for saturated and cis-monounsaturated fatty acids.These data suggest that a high intake of industrial trans fatty acids may decrease the risk of weight loss, particularly in women. Prevention of obesity should consider limiting the consumption of highly processed foods, the main source of industrially-produced trans fatty acids.

  17. A one-step colorimetric acid-base titration sensor using a complementary color changing coordination system.

    Cho, Hui Hun; Kim, Si Hyun; Heo, Jun Hyuk; Moon, Young Eel; Choi, Young Hun; Lim, Dong Cheol; Han, Kwon-Hoon; Lee, Jung Heon

    2016-06-21

    We report the development of a colorimetric sensor that allows for the quantitative measurement of the acid content via acid-base titration in a single-step. In order to create the sensor, we used a cobalt coordination system (Co-complex sensor) that changes from greenish blue colored Co(H2O)4(OH)2 to pink colored Co(H2O)6(2+) after neutralization. Greenish blue and pink are two complementary colors with a strong contrast. As a certain amount of acid is introduced to the Co-complex sensor, a portion of greenish blue colored Co(H2O)4(OH)2 changes to pink colored Co(H2O)6(2+), producing a different color. As the ratio of greenish blue and pink in the Co-complex sensor is determined by the amount of neutralization reaction occurring between Co(H2O)4(OH)2 and an acid, the sensor produced a spectrum of green, yellow green, brown, orange, and pink colors depending on the acid content. In contrast, the color change appeared only beyond the end point for normal acid-base titration. When we mixed this Co-complex sensor with different concentrations of citric acid, tartaric acid, and malic acid, three representative organic acids in fruits, we observed distinct color changes for each sample. This color change could also be observed in real fruit juice. When we treated the Co-complex sensor with real tangerine juice, it generated diverse colors depending on the concentration of citric acid in each sample. These results provide a new angle on simple but quantitative measurements of analytes for on-site usage in various applications, such as in food, farms, and the drug industry. PMID:27143645

  18. Preparation, characterization, and thermal properties of starch microencapsulated fatty acids as phase change materials thermal energy storage applications

    Stable starch-oil composites can be prepared from renewable resources by excess steam jet-cooking aqueous slurries of starch and vegetable oils or other hydrophobic materials. Fatty acids such as stearic acid are promising phase change materials (PCMs) for latent heat thermal energy storage applica...

  19. Seasonal changes in dominant bacterial taxa from acidic peatlands of the Atlantic Rain Forest.

    Etto, Rafael Mazer; Cruz, Leonardo Magalhães; da Conceição Jesus, Ederson; Galvão, Carolina Weigert; Galvão, Franklin; de Souza, Emanuel Maltempi; de Oliveira Pedrosa, Fábio; Reynaud Steffens, Maria Berenice

    2014-09-01

    The acidic peatlands of southern Brazil are essential for maintenance of the Atlantic Rain Forest, one of the 25 hot-spots of biodiversity in the world. While these ecosystems are closely linked to conservation issues, their microbial community ecology and composition remain unknown. In this work, histosol samples were collected from three acidic peatland regions during dry and rainy seasons and their chemical and microbial characteristics were evaluated. Culturing and culture-independent approaches based on SSU rRNA gene pyrosequencing were used to survey the bacterial community and to identify environmental factors affecting the biodiversity and microbial metabolic potential of the Brazilian peatlands. All acidic peatlands were dominated by the Acidobacteria phylum (56-22%) followed by Proteobacteria (28-12%). The OTU richness of these phyla and the abundance of their Gp1, Gp2, Gp3, Gp13, Rhodospirillales and Caulobacteriales members varied according to the period of collection and significantly correlated with the rainy season. However, despite changes in acidobacterial and proteobacterial communities, rainfall did not affect the microbial metabolic potential of the southern Brazilian Atlantic Rain Forest peatlands, as judged by the metabolic capabilities of the microbial community. PMID:24893336

  20. Bacterial dynamics and metabolite changes in solid-state acetic acid fermentation of Shanxi aged vinegar.

    Li, Sha; Li, Pan; Liu, Xiong; Luo, Lixin; Lin, Weifeng

    2016-05-01

    Solid-state acetic acid fermentation (AAF), a natural or semi-controlled fermentation process driven by reproducible microbial communities, is an important technique to produce traditional Chinese cereal vinegars. Highly complex microbial communities and metabolites are involved in traditional Chinese solid-state AAF, but the association between microbiota and metabolites during this process are still poorly understood. In this study, we performed amplicon 16S rRNA gene sequencing on the Illumina MiSeq platform, PCR-denaturing gradient gel electrophoresis, and metabolite analysis to trace the bacterial dynamics and metabolite changes under AAF process. A succession of bacterial assemblages was observed during the AAF process. Lactobacillales dominated all the stages. However, Acetobacter species in Rhodospirillales were considerably accelerated during AAF until the end of fermentation. Quantitative PCR results indicated that the biomass of total bacteria showed a "system microbe self-domestication" process in the first 3 days, and then peaked at the seventh day before gradually decreasing until the end of AAF. Moreover, a total of 88 metabolites, including 8 organic acids, 16 free amino acids, and 66 aroma compounds were detected during AAF. Principal component analysis and cluster analyses revealed the high correlation between the dynamics of bacterial community and metabolites. PMID:26754813

  1. Accrued somatic mutations (nucleic acid changes) trigger ALS: 2005-2015 update.

    Armon, Carmel

    2016-06-01

    Amyotrophic lateral sclerosis (ALS) is a multilevel disease of the motor neuron system. The mechanisms triggering disease onset should be considered separately from those facilitating its spread and motor neuron death. In 2005, I brought together clinical and epidemiological evidence to support the hypothesis that acquired nucleic acid changes may trigger sporadic ALS. Since 2005, the conceptual foundations for this hypothesis have been strengthened. The journal Amyotrophic Lateral Sclerosis was renamed Amyotrophic Lateral Sclerosis & Frontotemporal Degeneration. The focal onset, with simultaneous initial maximal upper and lower motor neuron involvement in the region of onset, and patterns of spread, were characterized further. Clues from the epidemiology of sporadic ALS were affirmed by quantitative analysis, including the increase in disease incidence with age, suggesting accrual of time-dependent changes, and the confirmation of smoking as an established risk factor. Additional observations support the conclusion that accrued somatic mutations trigger onset of ALS. Muscle Nerve 53: 842-849, 2016. PMID:26799358

  2. SIGN LANGUAGE CONVERTER

    Taner Arsan; Oğuz Ülgen

    2015-01-01

    The aim of this paper is to design a convenient system that is helpful for the people who have hearing difficulties and in general who use very simple and effective method; sign language. This system can be used for converting sign language to voice and also voice to sign language. A motion capture system is used for sign language conversion and a voice recognition system for voice conversion. It captures the signs and dictates on the screen as writing. It also captures the voice ...

  3. Cycloidal Wave Energy Converter

    Stefan G. Siegel, Ph.D.

    2012-11-30

    This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will

  4. Resonant power converters

    Kazimierczuk, Marian K

    2012-01-01

    This book is devoted to resonant energy conversion in power electronics. It is a practical, systematic guide to the analysis and design of various dc-dc resonant inverters, high-frequency rectifiers, and dc-dc resonant converters that are building blocks of many of today's high-frequency energy processors. Designed to function as both a superior senior-to-graduate level textbook for electrical engineering courses and a valuable professional reference for practicing engineers, it provides students and engineers with a solid grasp of existing high-frequency technology, while acquainting them wit

  5. Omega-3 polyunsaturated fatty acid supplementation and white matter changes in major depression.

    Chhetry, Binod Thapa; Hezghia, Adrienne; Miller, Jeffrey M; Lee, Seonjoo; Rubin-Falcone, Harry; Cooper, Thomas B; Oquendo, Maria A; Mann, J John; Sublette, M Elizabeth

    2016-04-01

    White matter abnormalities are implicated in major depressive disorder (MDD). As omega-3 polyunsaturated fatty acids (PUFAs) are low in MDD and affect myelination, we hypothesized that PUFA supplementation may alleviate depression through improving white matter integrity. Acutely depressed MDD patients (n = 16) and healthy volunteers (HV, n = 12) had 25-direction diffusion tensor imaging before and after 6 weeks of fish oil supplementation. Plasma phospholipid omega-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and omega-6 PUFA arachidonic acid (AA) levels were determined before and after supplementation using high-throughput extraction and gas chromatography and expressed as a percentage of total phospholipids (PUFA%). Fractional anisotropy (FA) was computed using a least-squares-fit diffusion tensor with non-linear optimization. Regression analyses were performed with changes in PUFA levels or Hamilton Depression Rating Scale scores as predictors, voxel-wise difference maps of FA as outcome, covariates age and sex, with family-wise correction for multiple comparisons. Increases in plasma phospholipid DHA% (but not EPA% or AA%) after fish oil predicted increases in FA in MDD but not HV, in a cluster including genu and body of the corpus callosum, and anterior corona radiata and cingulum (cluster-level p depression severity predicted increased FA in left corticospinal tract and superior longitudinal fasciculus (cluster-level p depression severity after fish oil supplementation suggests therapeutic effects of omega-3 PUFAs may be related to improvements in white matter integrity. PMID:26802812

  6. Changes in the viscosity of hyaluronic acid after exposure to a myeloperoxidase-derived oxidant

    Baker, M.S.; Green, S.P.; Lowther, D.A.

    1989-04-01

    Both purified hyaluronic acid (HA) and bovine synovial fluid react with OCI-, the major oxidant produced by the myeloperoxidase (MPO)/H/sub 2/O/sub 2//CI- system, resulting in a decrease in their specific viscosity. This reaction is inhibited in the presence of excess methionine. H/sub 2/O/sub 2/ alone decreases the viscosity of HA, presumably by the Fenton reaction, in the absence (but not in the presence) of the iron chelator, diethyltriaminepentacetic acid (DETAPAC). In the presence of DETAPAC, incubation of HA with the complete MPO/H/sub 2/O/sub 2//CI- system lowered the viscosity of HA. Analysis of 3H-HA exposed to OCI- by gel filtration chromatography indicated that cleavage of HA occurred only at higher OCI- concentrations. We suggest that the reduction in viscosity of HA by the MPO/H/sub 2/O/sub 2//CI- system may be due to a combination of oxidative cleavage and changes in the conformation of the molecule. We speculate that the changes in the molecular size of rheumatoid synovial fluid HA may be due to the action of the neutrophil MPO/H/sub 2/O/sub 2//CI- system.

  7. Changes in the viscosity of hyaluronic acid after exposure to a myeloperoxidase-derived oxidant

    Both purified hyaluronic acid (HA) and bovine synovial fluid react with OCI-, the major oxidant produced by the myeloperoxidase (MPO)/H2O2/CI- system, resulting in a decrease in their specific viscosity. This reaction is inhibited in the presence of excess methionine. H2O2 alone decreases the viscosity of HA, presumably by the Fenton reaction, in the absence (but not in the presence) of the iron chelator, diethyltriaminepentacetic acid (DETAPAC). In the presence of DETAPAC, incubation of HA with the complete MPO/H2O2/CI- system lowered the viscosity of HA. Analysis of 3H-HA exposed to OCI- by gel filtration chromatography indicated that cleavage of HA occurred only at higher OCI- concentrations. We suggest that the reduction in viscosity of HA by the MPO/H2O2/CI- system may be due to a combination of oxidative cleavage and changes in the conformation of the molecule. We speculate that the changes in the molecular size of rheumatoid synovial fluid HA may be due to the action of the neutrophil MPO/H2O2/CI- system

  8. Conjugated linoleic acid mitigates testosterone-related changes in body composition in male guinea pigs.

    Yang, Susan Q; DeGuire, Jason R; Lavery, Paula; Mak, Ivy L; Weiler, Hope A; Santosa, Sylvia

    2016-05-01

    We hypothesize that conjugated linoleic acid (CLA) may be effective in preventing the changes in total and regional body composition and increases in interleukin (IL) 6 that occur as a result of hypogonadism. Male guinea pigs (n = 40, 70- to 72-week retired breeders) were block randomized by weight into 4 groups: (1) sham surgery (SHAM)/control (CTRL) diet, (2) SHAM/conjugated linoleic acid (CLA) diet (1%), (3) orchidectomy (ORX)/CTRL diet, and (4) ORX/CLA diet. Dual-energy x-ray absorptiometry scans were performed at baseline and week 16 to assess body composition. Serum IL-6 was analyzed using an enzyme-linked immune sorbent assay. Fatty acids (FAs) from visceral and subcutaneous adipose tissue were analyzed using gas chromatography. In ORX/CTRL guinea pigs, percent total body fat increased by 6.1%, and percent lean mass decreased by 6.7% over the 16-week treatment period, whereas no changes were observed for either parameter in ORX/CLA guinea pigs. Guinea pigs fed the CLA diet gained less percent total, upper, and lower body fat than those fed the CTRL diet regardless of surgical treatment. Regional adipose tissue FA composition was reflective of dietary FAs. Serum IL-6 concentrations were not different among groups. In this study, we observed that, in male guinea pigs, hypogonadism resulted in increased fat mass and decreased lean mass. In addition, CLA was effective in reducing gains in body fat and maintaining lean mass in both hypogonadal and intact guinea pigs. PMID:27101759

  9. Dynamic changes of excitatory amino acid receptors in the rat hippocampus following transient cerebral ischemia

    The changes in excitatory amino acid receptor ligand binding induced by transient cerebral ischemia were studied in the rat hippocampal subfields. Ten minutes of ischemia was induced by common carotid artery occlusion combined with hypotension, and the animals were allowed variable periods of recovery ranging from 1 day to 4 weeks. The binding of 3H-AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) to quisqualate receptors, 3H-kainic acid (KA) to kainate receptors, and 3H-glutamate to N-methyl-D-aspartate (NMDA) receptors as determined by quantitative autoradiography. One week following ischemia the CA1 region of the hippocampus displayed a severe (90%) dendrosomatic lesion with preservation of presynaptic terminals. This was associated with a 60% decrease in AMPA binding and a 25% decrease in glutamate binding to NMDA receptors. At 4 weeks postischemia, both AMPA and NMDA sites were greatly reduced. Although the dentate gyrus granule cells are resistant to an ischemic insult of this magnitude, this region showed marked changes in receptor binding. One week following ischemia, the AMPA and NMDA binding decreased by approximately 40 and 20%, respectively. Following 2 weeks of recovery, the NMDA binding was not significantly different from control level, while the AMPA binding remained depressed up to 4 weeks postischemia. The high density of KA binding sites in the inner molecular layer of the dentate gyrus was unaffected by the ischemic insult, despite an extensive degeneration of cells in the hilus of dentate gyrus which projects glutamatergic afferents to this area

  10. Converter applications and their influence on large electrical machines

    Drubel, Oliver

    2013-01-01

    Converter driven applications are applied in more and more processes. Almost any installed wind-farm, ship drives, steel mills, several boiler feed water pumps, extruder and many other applications operate much more efficient and economic in case of variable speed solutions. The boundary conditions for a motor or generator will change, if it is supplied by a converter. An electrical machine, which is operated by a converter, can no longer be regarded as an independent component, but is embedded in a system consisting of converter and machine. This book gives an overview of existing converter designs for large electrical machines. Methods for the appropriate calculation of machine phenomena, which are implied by converters are derived in the power range above 500kVA. It is shown how due to the converter inherent higher voltage harmonics and pulse frequencies special phenomena are caused inside the machine which can be the reason for malfunction. It is demonstrated that additional losses create additional tempe...

  11. Changes of free amino acids during rumen fermentation and incorporation of urea-15N into microorganisms in vitro

    Nitrogen-15 in urea was incorporated into NH3-N, bacteria-N, and 2,000 rpm-precipitate fraction-N with time course changes. The degree of incorporation was more intensely in U5 experiment than in U3 experiment. The highest 15N concentration in the bacterial fraction appeared after 6 and 12 hours after the beginning of incubation in the case of U3 and U5, respectively. The time course changes in 15N concentration in the 2,000 rpm-precipitate fraction were in parallel with that in the bacterial fraction except for 24 hours. The changes in concentration of free amino acids in the medium were observed in lysine, aspartic acid, and alanine remarkably. The concentration of total free amino acids changed with the lapse of time. The total concentration in the case of U3 experiment decreased gradually until 6 hours, and then increased until 24 hours. On the other hand, the total concentration in the case of U5 decreased continuously except for the slight increase at 6 hours. Each amino acid was isolated from the hydrolyzate of the 2,000 rpm-precipitate fraction by column chromatography. Each 15N concentration was determined for isolated amino acids. Consequently, 15N concentrations were relatively high in glysine, alanine, glutamic acid, and aspartic acid. On the contrary, 15N concentrations were very low in methionine and cystine. (JPN)

  12. Amino Acid Change in an Orchid Desaturase Enables Mimicry of the Pollinator's Sex Pheromone.

    Sedeek, Khalid E M; Whittle, Edward; Guthörl, Daniela; Grossniklaus, Ueli; Shanklin, John; Schlüter, Philipp M

    2016-06-01

    Mimicry illustrates the power of selection to produce phenotypic convergence in biology [1]. A striking example is the imitation of female insects by plants that are pollinated by sexual deception of males of the same insect species [2-4]. This involves mimicry of visual, tactile, and chemical signals of females [2-7], especially their sex pheromones [8-11]. The Mediterranean orchid Ophrys exaltata employs chemical mimicry of cuticular hydrocarbons, particularly the 7-alkenes, in an insect sex pheromone to attract and elicit mating behavior in its pollinators, males of the cellophane bee Colletes cunicularius [11-13]. A difference in alkene double-bond positions is responsible for reproductive isolation between O. exaltata and closely related species, such as O. sphegodes [13-16]. We show that these 7-alkenes are likely determined by the action of the stearoyl-acyl-carrier-protein desaturase (SAD) homolog SAD5. After gene duplication, changes in subcellular localization relative to the ancestral housekeeping desaturase may have allowed proto-SAD5's reaction products to undergo further biosynthesis to both 7- and 9-alkenes. Such ancestral coproduction of two alkene classes may have led to pollinator-mediated deleterious pleiotropy. Despite possible evolutionary intermediates with reduced activity, amino acid changes at the bottom of the substrate-binding cavity have conferred enzyme specificity for 7-alkene biosynthesis by preventing the binding of longer-chained fatty acid (FA) precursors by the enzyme. This change in desaturase function enabled the orchid to perfect its chemical mimicry of pollinator sex pheromones by escape from deleterious pleiotropy, supporting a role of pleiotropy in determining the possible trajectories of adaptive evolution. PMID:27212404

  13. Binding of the substrate UDP-glucuronic acid induces conformational changes in the xanthan gum glucuronosyltransferase.

    Salinas, S R; Petruk, A A; Brukman, N G; Bianco, M I; Jacobs, M; Marti, M A; Ielpi, L

    2016-06-01

    GumK is a membrane-associated glucuronosyltransferase of Xanthomonas campestris that is involved in xanthan gum biosynthesis. GumK belongs to the inverting GT-B superfamily and catalyzes the transfer of a glucuronic acid (GlcA) residue from uridine diphosphate (UDP)-GlcA (UDP-GlcA) to a lipid-PP-trisaccharide embedded in the membrane of the bacteria. The structure of GumK was previously described in its apo- and UDP-bound forms, with no significant conformational differences being observed. Here, we study the behavior of GumK toward its donor substrate UDP-GlcA. Turbidity measurements revealed that the interaction of GumK with UDP-GlcA produces aggregation of protein molecules under specific conditions. Moreover, limited proteolysis assays demonstrated protection of enzymatic digestion when UDP-GlcA is present, and this protection is promoted by substrate binding. Circular dichroism spectroscopy also revealed changes in the GumK tertiary structure after UDP-GlcA addition. According to the obtained emission fluorescence results, we suggest the possibility of exposure of hydrophobic residues upon UDP-GlcA binding. We present in silico-built models of GumK complexed with UDP-GlcA as well as its analogs UDP-glucose and UDP-galacturonic acid. Through molecular dynamics simulations, we also show that a relative movement between the domains appears to be specific and to be triggered by UDP-GlcA. The results presented here strongly suggest that GumK undergoes a conformational change upon donor substrate binding, likely bringing the two Rossmann fold domains closer together and triggering a change in the N-terminal domain, with consequent generation of the acceptor substrate binding site. PMID:27099353

  14. Sodium arsenate induce changes in fatty acids profiles and oxidative damage in kidney of rats.

    Kharroubi, Wafa; Dhibi, Madiha; Mekni, Manel; Haouas, Zohra; Chreif, Imed; Neffati, Fadoua; Hammami, Mohamed; Sakly, Rachid

    2014-10-01

    Six groups of rats (n = 10 per group) were exposed to 1 and 10 mg/l of sodium arsenate for 45 and 90 days. Kidneys from treated groups exposed to arsenic showed higher levels of trans isomers of oleic and linoleic acids as trans C181n-9, trans C18:1n-11, and trans C18:2n-6 isomers. However, a significant decrease in eicosenoic (C20:1n-9) and arachidonic (C20:4n-6) acids were observed in treated rats. Moreover, the "Δ5 desaturase index" and the saturated/polyunsaturated fatty acids ratio were increased. There was a significant increase in the level of malondialdehyde at 10 mg/l of treatment and in the amount of conjugated dienes after 90 days (p < 0.05). Significant kidney damage was observed at 10 mg/l by increase of plasma marker enzymes. Histological studies on the ultrastructure changes of kidney supported the toxic effect of arsenate exposure. Arsenate intoxication activates significantly the superoxide dismutase at 10 mg/l for 90 days, whereas the catalase activity was markedly inhibited in all treated groups (p < 0.05). In addition, glutathione peroxidase activity was significantly increased at 45 days and dramatically declined after 90 days at 10 mg/l (p < 0.05). A significant increase in the level of glutathione was marked for the groups treated for 45 and 90 days at 1 mg/l followed by a significant decrease for rats exposed to 10 mg/l for 90 days. An increase in the level of protein carbonyl was observed in all treated groups (p < 0.05). In conclusion, the present study provides evidence for a direct effect of arsenate on fatty acid (FA) metabolism which concerns the synthesis pathway of n-6 polyunsaturated fatty acids and leads to an increase in the trans FAs isomers. Therefore, FA-induced arsenate kidney damage could contribute to trigger kidney cancer. PMID:24920263

  15. Power converters for ITER

    Benfatto, I

    2006-01-01

    The International Thermonuclear Experimental Reactor (ITER) is a thermonuclear fusion experiment designed to provide long deuterium– tritium burning plasma operation. After a short description of ITER objectives, the main design parameters and the construction schedule, the paper describes the electrical characteristics of the French 400 kV grid at Cadarache: the European site proposed for ITER. Moreover, the paper describes the main requirements and features of the power converters designed for the ITER coil and additional heating power supplies, characterized by a total installed power of about 1.8 GVA, modular design with basic units up to 90 MVA continuous duty, dc currents up to 68 kA, and voltages from 1 kV to 1 MV dc.

  16. Heated catalytic converter

    1994-09-01

    This article describes how the use of an auxiliary burner to heat the converter promptly can provide substantially decreased emission levels. While, in principle, there may well be solutions to decreasing warm-up phase hydrocarbon emissions, their production-level implementation is hindered by conflicting requirements, insufficiently mature technologies, and significant technical and financial restraints. The US, California, and the European Community are tightening emission standards for the transitional-low-, low-, and ultra-low-emission vehicles throughout the coming decade. The lead figure shows the fundamental possibilities for reducing harmful substances in exhaust emissions. While one can distinguish between measures taken within the engine (internal), and others outside it (external), it currently seems that only a combination of both will provide a suitable overall concept.

  17. Electromagnetic wave energy converter

    Bailey, R. L. (Inventor)

    1973-01-01

    Electromagnetic wave energy is converted into electric power with an array of mutually insulated electromagnetic wave absorber elements each responsive to an electric field component of the wave as it impinges thereon. Each element includes a portion tapered in the direction of wave propagation to provide a relatively wideband response spectrum. Each element includes an output for deriving a voltage replica of the electric field variations intercepted by it. Adjacent elements are positioned relative to each other so that an electric field subsists between adjacent elements in response to the impinging wave. The electric field results in a voltage difference between adjacent elements that is fed to a rectifier to derive dc output power.

  18. Two phase interleaved buck converter for driving high power LEDs

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2011-01-01

    The goal of this paper is to evaluate an interleaved buck topology for driving high current light-emitting diodes. Low output capacitor value allows the use of non-electrolytic capacitors extending the lifetime of the converter. Converter is operated as a constant, regulated current source which increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By sett...

  19. Conducted EMI Evaluation and Reduction in a Forward Switching Converter

    Mohammad Rouhollah Yazdani; Nahid Amini Filabadi

    2012-01-01

    In switching power converters, electromagnetic interference (EMI) is produced due to the fast changes of the voltage and current. Among switching topologies used in low and medium powers, forward converter is vastly employed which needs resetting transformer core. In this paper, a forward converter with reset winding is modeled to predict conducted EMI. To evaluate the EMI model, EMI measurement results are presented. To select an optimum reset scheme from EMI viewpoint, three reset technique...

  20. Changes in leaf proteome profile of Arabidopsis thaliana in response to salicylic acid

    Riddhi Datta; Ragini Sinha; Sharmila Chattopadhyay

    2013-06-01

    Salicylic acid (SA) has been implicated in determining the outcome of interactions between many plants and their pathogens. Global changes in response to this phytohormone have been observed at the transcript level, but little is known of how it induces changes in protein abundance. To this end we have investigated the effect of 1 mM SA on soluble proteins of Arabidopsis thaliana leaves by proteomic analysis. An initial study at transcript level has been performed on temporal landscape, which revealed that induction of most of the SA-responsive genes occurs within 3 to 6 h post treatment (HPT) and the expression peaked within 24 HPT. Two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF MS/MS analysis has been used to identify differentially expressed proteins and 63 spots have been identified successfully. This comparative proteomic profiling of SA treated leaves versus control leaves demonstrated the changes of many defence related proteins like pathogenesis related protein 10a (PR10a), disease-resistance-like protein, putative late blight-resistance protein, WRKY4, MYB4, etc. along with gross increase in the rate of energy production, while other general metabolism rate is slightly toned down, presumably signifying a transition from ‘normal mode’ to ‘defence mode’.

  1. Integrated power electronic converters and digital control

    Emadi, Ali; Nie, Zhong

    2009-01-01

    Non-isolated DC-DC ConvertersBuck ConverterBoost ConverterBuck-Boost ConverterIsolated DC-DC ConvertersFlyback ConverterForward ConverterPush-Pull ConverterFull-Bridge ConverterHalf-Bridge ConverterPower Factor CorrectionConcept of PFCGeneral Classification of PFC CircuitsHigh Switching Frequency Topologies for PFCApplication of PFC in Advanced Motor DrivesIntegrated Switched-Mode Power ConvertersSwitched-Mode Power SuppliesThe Concept of Integrated ConverterDefinition of Integrated Switched-Mode Power Supplies (ISMPS)Boost-Type Integrated TopologiesGeneral Structure of Boost-Type Integrated T

  2. Relative quantification of phosphoproteomic changes in grapevine (Vitis vinifera L.) leaves in response to abscisic acid

    Rattanakan, Supakan; George, Iniga; Haynes, Paul A; Cramer, Grant R

    2016-01-01

    In a previous transcriptomic analysis, abscisic acid (ABA) was found to affect the abundance of a number of transcripts in leaves of Cabernet Sauvignon grapevines with roots that had been exposed to 10 μm ABA for 2 h. Other work has indicated that ABA affects protein abundance and protein phosphorylation as well. In this study we investigated changes in protein abundance and phosphorylation of Cabernet Sauvignon grapevine leaves. Protein abundance was assessed by both label-free and isobaric-label quantitive proteomic methods. Each identified common proteins, but also additional proteins not found with the other method. Overall, several thousand proteins were identified and several hundred were quantified. In addition, hundreds of phosphoproteins were identified. Tens of proteins were found to be affected in the leaf after the roots had been exposed to ABA for 2 h, more than half of them were phosphorylated proteins. Many phosphosites were confirmed and several new ones were identified. ABA increased the abundance of some proteins, but the majority of the proteins had their protein abundance decreased. Many of these proteins were involved in growth and plant organ development, including proteins involved in protein synthesis, photosynthesis, sugar and amino-acid metabolism. This study provides new insights into how ABA regulates plant responses and acclimation to water deficits. PMID:27366326

  3. Temperature- and moisture-dependent phase changes in crystal forms of barbituric acid

    The dihydrate of barbituric acid (BAc) and its dehydration product, form II were investigated by means of moisture sorption analysis, hot-stage microscopy, differential scanning calorimetry, thermogravimetry, solution calorimetry, IR- and Raman-spectroscopy as well as powder X-ray diffraction. The dihydrate desolvates already at and below 50% relative humidity (RH) at 25 deg. C whereas form II is stable up to 80% RH, where it transforms back to the dihydrate. The thermal dehydration of barbituric acid dihydrate (BAc-H2) is a single step, nucleation controlled process. The peritectic reaction of the hydrate was measured at 77 deg. C and a transformation enthalpy of ΔtrsHH2-II = 17.3 kJ mol-1 was calculated for the interconversion between the hydrate and form II. An almost identical value of 17.0 kJ mol-1 was obtained from solution calorimetry in water as solvent (ΔsolHH2 = 41.5, ΔsolHII = 24.5 kJ mol-1). Additionally a high-temperature form (HT-form) of BAc, which is enantiotropically related to form II and unstable at ambient conditions has been characterized. Furthermore, we observed that grinding of BAc with potassium bromide (KBr) induces a tautomeric change. Therefore, IR-spectra recorded with KBr-discs usually display a mixture of tautomers, whereas the IR-spectra of the pure trioxo-form of BAc are obtained if alternative preparation techniques are used

  4. Acid-induced change in ozone-reactive site in indole ring of tryptophan

    It is well established that ozone as well as oxygen activated by tryptophan 2,3-dioxygenase or indoleamine 2,3-dioxygenase cleave the 2,3-C=C bond of the indole ring of tryptophan to produce N-formylkynurenine. In the present study, however, we found that exposure of tryptophan to aqueous ozone at and below pH 4.5 generated a different compound. The compound was identified as kynurenine by high performance liquid chromatography and mass spectrometry. Exposure of N-formylkynurenine to acidic ozone did not generate a significant amount of kynurenine, indicating that the kynurenine was not produced via N-formylkynurenine. Acidic ozone thus appears to cleave the 1, 2-N-C bond in place of the 2,3-C=C bond of the indole ring, followed by liberation of the 2-C atom. The 1,2-N-C bond and 2,3-C=C bond are likely to undergo changes in their nature of bonding on acidification, enabling ozone to react with the former bond but not with the latter bond.

  5. Vacuum-insulated catalytic converter

    Benson, David K. (Golden, CO)

    2001-01-01

    A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

  6. Advanced power electronics converters PWM converters processing AC voltages

    dos Santos, Euzeli

    2014-01-01

    This book covers power electronics, in depth, by presenting the basic principles and application details, which can be used both as a textbook and reference book.  Introduces a new method to present power electronics converters called Power Blocks Geometry. Applicable for courses focusing on power electronics, power electronics converters, and advanced power converters. Offers a comprehensive set of simulation results to help understand the circuits presented throughout the book

  7. Seasonal changes in the microbial community of a salt marsh, measured by phospholipid fatty acid analysis

    Keith-Roach, Miranda; Bryan, N.D.; Bardgett, R.D.;

    2002-01-01

    to characterise biogeochemical processes occurring at this site. Phospholipid fatty acid (PLFA) analysis of sediment samples collected at monthly intervals was used to measure seasonal changes in microbial biomass and community structure. The PLFA data were analysed using multivariate techniques...... (Ward's method and the Mahalanobis distance metric), and we show that the use of the Mahalanobis distance metric improves the statistical analysis by providing detailed information on the reasons samples cluster together and identifying the distinguishing features between the separate clusters. Five...... increases in the abundance of PLFA, in the warmer months. The conditions therefore remained most favourable for aerobic species throughout the year, explaining their continual dominance at this site. However, as the abundance of PLFA synthesised by anaerobes increased, increases in dissolved Mn...

  8. The response of amino acid cycling to global change across multiple biomes: Feedbacks on soil nitrogen availability

    Brzostek, E. R.; Finzi, A. C.

    2010-12-01

    The cycling of organic nitrogen (N) in soil links soil organic matter decomposition to ecosystem productivity. Amino acids are a key pool of organic N in the soil, whose cycling is sensitive to alterations in microbial demand for carbon and N. Further, the amino acids released from the breakdown of protein by proteolytic enzymes are an important source of N that supports terrestrial productivity. The objective of this study was to measure changes in amino acid cycling in response to experimental alterations of precipitation and temperature in twelve global change experiments during the 2009 growing season. The study sites ranged from arctic tundra to xeric grasslands. The treatments experimentally increased temperature, increased or decreased precipitation, or some combination of both factors. The response of amino acid cycling to temperature and precipitation manipulations tended to be site specific, but the responses could be placed into a common framework. Changes in soil moisture drove a large response in amino acid cycling. Precipitation augmentation in xeric and mesic sites increased both amino acid pool sizes and production. However, treatments that decreased precipitation drove decreases in amino acid cycling in xeric sites, but led to increases in amino acid cycling in more mesic sites. Across sites, the response to soil warming was horizon specific. Amino acid cycling in organic rich horizons responded positively to warming, while negative responses were exhibited in lower mineral soil horizons. The variable response likely reflects a higher availability of protein substrate to sustain high rates of proteolytic enzyme activity in organic rich horizons. Overall, these results suggest that soil moisture and the availability of protein substrate may be important factors that mediate the response of amino acid cycling to predicted increases in soil temperatures.

  9. Role of Changes in Cell Fatty Acids Composition in the Increasing of Frost Resistance of Winter Wheat Suspension Culture

    I.V. Lyubushkina

    2013-11-01

    Full Text Available Influences of low temperatures (4 and 8 ° С on the frost tolerance and fatty acid compositions of cells in a winter wheat suspension culture have been studied. It has been found that treatment of the culture with 4 °C (7 days did not protect cells from subsequent freezing temperature action (-8 °С, 6 h and was not accompanied significant changes in the fatty acid composition. On the contrary, the treatment of the culture with the temperature 8 °C (7 days prevented the death caused by freezing temperature and the content of saturated fatty acids decreased: pentadecanoic acid (by 35,0%, palmitic acid (by 19,9% and stearic acid (by 65,4%, and the content of α-linolenic acid increased by 94%. That was the cause of the double bond index (DBI increase by 16%. The role of fatty acids composition changes in the process of increasing frost tolerance in plants are discussed.

  10. CHANGES IN THE CHARDONNAY CLONES ORGANIC ACIDS RATIO DURING MATURATION TIME

    Ana Jeromel

    2007-12-01

    Full Text Available Tartaric and malic acids are essential constituents of grape must and wine, contributing directly to its taste as well as balancing with other flavors. High temperature conditions during maturation time can strongly affect malic acid/tartaric acid ratio resulting in a lower acid content due to increasing degradation of malic acid. In the 2006 year Chardonnay grape (clone SMA 130, CL 95, CL96, CL548, SMA 123, R8, VCR10 from Zagreb wine region was collected every 3-5 days from the moment of verasion until the harvest time. The smallest malic acid/tartaric acid ratio was detected in CL 95 clone while clone CL 96 and VCR10 had the highest malic acid/tartaric acid ratio. There was no difference in the citric acid content among tested clones.

  11. Starvation on changes in growth and fatty acid composition of juvenile red swamp crawfish, Procambarus clarkii

    WEN Xiaobo; KU Yaomei; ZHOU Kaiya

    2007-01-01

    The effect of starvation on physiological and biochemical indicators of body, muscle and hepatopancreas were investigated for juvenile red swamp crawfish (Procambarus clarkii), and the results showed the effect was obvious. In a 70-day starvation experiment, mean body weight, exuvial rate, abdominal muscle ratio and hepatosomatic index decreased significantly. The percentage of protein, fat, ash and moisture were also significantly affected. The protein content decreased sharply at Day 30 onward and the percentage of fat decreased rapidly from Day 50 and on. The percentages of ash and moisture started to increase significantly at Day 40 and 30 respectively. After the starvation experiment, the hepatopancreatic total and neutral lipid content decreased slightly from 23.90% to 20.39% and 73.75% to 70.35%, while the hepatopancreatic polar lipid content increased from 23.81% to 27.32%. On the other hand, all the muscular total, neutral and polar lipid contents, and the muscular fatty acid compositions did not change significantly except for the hepatopancreatic fatty acid composition. The relative percentages of 14:0, 16:0, 16:1n-7 and 18:1n-9 were decreased by 55.17%, 11.11%, 8.5% and 6.70% from the initial values, and the relative percentages of 18:2n-6, 18:3n-3, 20:4n-6, 20:5n-3 and 22:6n-3 increased obviously from 5.2%, 3.9%, 2.4%, 10.6%, and 13.7% to 7.1%, 5.0%, 2.8%, 11.5% , and 14.4% respectively.Preference of utilization of fatty acids from hepatopancreas during starvation was as follows:14:0>16:0>16:1n-7>18:1n-9, and the conservation of highly unsaturated fatty acids was in the order of:18:2n-6 > 18:3n-3>20:4n-6>20:5n-3>22:6n-3.

  12. Dermatan Sulfate Epimerase 1-Deficient Mice Have Reduced Content and Changed Distribution of Iduronic Acids in Dermatan Sulfate and an Altered Collagen Structure in Skin

    Maccarana, M.; Kalamajski, S.; Kongsgaard, M.; Magnusson, S.P.; Oldberg, A.; Malmstrom, A.

    2009-01-01

    Dermatan sulfate epimerase 1 (DS-epi1) and DS-epi2 convert glucuronic acid to iduronic acid in chondroitin/dermatan sulfate biosynthesis. Here we report on the generation of DS-epi1-null mice and the resulting alterations in the chondroitin/dermatan polysaccharide chains. The numbers of long blocks...... of adjacent iduronic acids are greatly decreased in skin decorin and biglycan chondroitin/dermatan sulfate, along with a parallel decrease in iduronic-2-O-sulfated-galactosamine-4-O-sulfated structures. Both iduronic acid blocks and iduronic acids surrounded by glucuronic acids are also decreased in...... versican-derived chains. DS-epi1-deficient mice are smaller than their wild-type littermates but otherwise have no gross macroscopic alterations. The lack of DS-epi1 affects the chondroitin/dermatan sulfate in many proteoglycans, and the consequences for skin collagen structure were initially analyzed. We...

  13. High-Performance Data Converters

    Steensgaard-Madsen, Jesper

    in a standard CMOS technology, they can be designed to yield 100 dB performance at 10 times oversampling. The proposed scaled-element mismatch-shaping D/A converters are well suited for use as the feedback stage in oversampled delta-sigma quantizers. It is, however, not easy to make full use of their......Novel techniques for multi-bit oversampled data conversion are described. State-of-the-art oversampled data converters are analyzed, leading to the conclusion that their performance is limited mainly by low-resolution signal representation. To increase the resolution, high-performance, high......-resolution internal D/A converters are required. Unit-element mismatch-shaping D/A converters are analyzed, and the concept of mismatch-shaping is generalized to include scaled-element D/A converters. Several types of scaled-element mismatch-shaping D/A converters are proposed. Simulations show that, when implemented...

  14. Dermatan Sulfate Epimerase 1-Deficient Mice Have Reduced Content and Changed Distribution of Iduronic Acids in Dermatan Sulfate and an Altered Collagen Structure in Skin▿

    Maccarana, Marco; Kalamajski, Sebastian; Kongsgaard, Mads; Magnusson, S. Peter; Oldberg, Åke; Malmström, Anders

    2009-01-01

    Dermatan sulfate epimerase 1 (DS-epi1) and DS-epi2 convert glucuronic acid to iduronic acid in chondroitin/dermatan sulfate biosynthesis. Here we report on the generation of DS-epi1-null mice and the resulting alterations in the chondroitin/dermatan polysaccharide chains. The numbers of long blocks of adjacent iduronic acids are greatly decreased in skin decorin and biglycan chondroitin/dermatan sulfate, along with a parallel decrease in iduronic-2-O-sulfated-galactosamine-4-O-sulfated struct...

  15. Histological changes caused by meclofenamic acid in androgen independent prostate cancer tumors: evaluation in a mouse model

    Iván Delgado-Enciso

    2015-10-01

    Full Text Available ABSTRACT Meclofenamic acid is a nonsteroidal anti-inflammatory drug that has shown therapeutic potential for different types of cancers, including androgen-independent prostate neoplasms. The antitumor effect of diverse nonsteroidal anti-inflammatory drugs has been shown to be accompanied by histological and molecular changes that are responsible for this beneficial effect. The objective of the present work was to analyze the histological changes caused by meclofenamic acid in androgen-independent prostate cancer. Tumors were created in a nude mouse model using PC3 cancerous human cells. Meclofenamic acid (10 mg/kg/day; experimental group, n=5 or saline solution (control group, n=5 was administered intraperitoneally for twenty days. Histological analysis was then carried out on the tumors, describing changes in the cellular architecture, fibrosis, and quantification of cellular proliferation and tumor vasculature. Meclofenamic acid causes histological changes that indicate less tumor aggression (less hypercellularity, fewer atypical mitoses, and fewer nuclear polymorphisms, an increase in fibrosis, and reduced cellular proliferation and tumor vascularity. Further studies are needed to evaluate the molecular changes that cause the beneficial and therapeutic effects of meclofenamic acid in androgen-independent prostate cancer.

  16. Thermal characteristic reliability of fatty acid binary mixtures as phase change materials (PCMs) for thermal energy storage applications

    The thermal characteristic reliability of two binary mixtures of fatty acid, myristic acid/palmitic acid/sodium myristate (MA/PA/SM) and myristic acid/palmitic acid/sodium palmitate (MA/PA/SP), were investigated using a thermal cycling test setup for 0, 1000, 2000, 3000, and 3600 heating/cooling cycles. The changes in thermal properties and chemical bonding of both eutectic PCMs were measured using Differential Scanning Calorimetric (DSC) and Fourier Transform Infrared Spectroscopy (FT-IR) analyzer, respectively. MA/PA/SM and MA/PA/SP eutectic mixtures shows only minor changes in phase transition temperature (Tm, Ts) and in latent heat of fusion (ΔHf). Moreover, the chemical bonding structures of these eutectic PCMs show no degradation and the thermal performance of those PCMs shows a good stability after 3600 thermal cycles. Therefore, it is found that the thermal characteristic stability of prepared MA/PA/SM and MA/PA/SP eutectic mixtures were acceptable for long term performance and economic feasibilities used as a phase change material (PCM) for thermal energy storage (TES) application. - Highlights: • The MA/PA/SM and MA/PA/SP were used as eutectic phase change materials (PCM). • Thermal reliability of eutectic PCMs evaluated using a thermal cycling test. • MA/PA/SP has a great thermal characteristic than MA/PA/SM after 3600 thermal cycles. • The eutectic PCMs did not show change of appearance after 3600 thermal cycles

  17. Adipose tissue trans fatty acids and changes in body weight and waist circumference

    Hansen, Camilla P.; Berentzen, Tina L.; Østergaard, Jane N.;

    2014-01-01

    Previous studies have suggested that the intake of trans-fatty acids (TFA) plays a role in the development of obesity. The proportions of adipose tissue fatty acids not synthesised endogenously in humans, such as TFA, usually correlate well with the dietary intake. Hence, the use of these...... biomarkers may provide a more accurate measure of habitual TFA intake than that obtained with dietary questionnaires. The objective of the present study was to investigate the associations between the proportions of specific TFA in adipose tissue and subsequent changes in weight and waist circumference (WC......% central range 0·98, 2·19) in men and 1·47% (1·01, 2·19) in women. No significant associations were observed between the proportions of total 18 : 1t, 18:1 D6-10t, vaccenic acid or rumenic acid and changes in weight or WC. The present study suggests that the proportions of specific TFA in adipose tissue...

  18. Low pressure solar thermal converter

    Muller, Gerald

    2010-01-01

    The current development of solar power converters with air as working fluid focuses mostly on concentrating collectors combined with hot-air engines, and on very low temperature solar tower concepts. Whilst concentrating collectors and Stirling engines need complex technology, solar tower converters have very low efficiencies and require large installations. Pressurized containers as energy converters offer the advantage of simplicity, but appear not to have been investigated in detail. ...

  19. Transient changes in the limbic histaminergic system after systemic kainic acid-induced seizures.

    Lintunen, Minnamaija; Sallmen, Tina; Karlstedt, Kaj; Panula, Pertti

    2005-10-01

    Increased brain histamine is reported to protect against convulsions. We used systemic kainic acid (KA) administration to study possible changes of the histaminergic system in rat brain in status epilepticus (SE). Robust increases in brain histamine concentrations and numbers of histamine-immunoreactive nerve fibers were detected in the piriform cortex (Pir) and amygdala after KA injection, suggesting a reactive increase, which is opposite to other published aminergic transmitter responses. These changes, lasting several weeks, might be coupled to a mechanism unrelated to the anticonvulsive function of histamine. Transient increases in mRNA expression of H(3) receptor isoforms with a full-length third intracellular loop, coupled to mitogen-activated protein kinase pathway, were detected first in the hippocampal CA3c area, followed by the Pir and amygdala and then the hippocampal CA1 area. These results suggest that histamine and H3 receptors, which also control the release of GABA and glutamate, might be involved in convulsive SE. PMID:16137576

  20. The change of fatty acids composition of Polish biscuits during storage.

    Koczoń, Piotr; Lipińska, Edyta; Czerniawska-Piątkowska, Ewa; Mikuła, Małgorzata; Bartyzel, Bartłomiej J

    2016-07-01

    Commercially available Polish biscuits were stored for 10months under different storage conditions i.e. in temperatures of 5°C and 20°C. The chemical quality alteration caused by chemical reactions occurring within biscuits were studied in terms of change of composition of fat extracted from studied samples in one-month intervals. Correlation of data from standard methods e.g. gas chromatography or classic titration with FT-IR spectroscopy, was followed by calculation of four statistical models that accurately predicted peroxide value, oxidative stability, polar fraction content and unsaturated trans fatty acid content in any samples. On the basis of data obtained, scheme of chemical reactions involved in oxidation process was suggested. A critical time of storage was proposed as an indicator of the period of the highest rate of chemical changes. Among factors considered to influence oxidative stability, the following had the greatest impact: initial water content, initial fat content, and time of storage. PMID:26920303

  1. Venturini Method Based Matrix Converter

    Derick Mathew

    2015-03-01

    Full Text Available Recently, matrix converter has received considerable interest as a viable alternative to the conventional ac-dc-ac converter. This direct ac-ac converter provides some attractive characteristics such as: four quadrant operation, absence of bulky dc-link electrolyte capacitors, clean input power characteristics. Due to the absence of dc link energy storage elements any disturbance in the input voltage will be immediately reflected to the output voltages. In this paper venturini method for matrix converter has been presented. Three phase sinusoidal symmetrical voltage or current can obtained .

  2. Adipose tissue trans fatty acids and changes in body weight and waist circumference

    Hansen, C.P.; Berentzen, T.L.; Østergaard, J.N.;

    Previous studies have suggested that intake of trans fatty acids (TFA) may play a role in the development of obesity. For fatty acids not synthesized endogenously in humans, such as TFA, the proportions in adipose tissue tend to correlate well with the habitual dietary intake. Biomarkers may...... provide a more accurate measure of habitual TFA intake than dietary questionnaires. Our objective was to investigate the associations between specific TFA in adipose tissue and subsequent changes in body weight and waist circumference (WC)....

  3. Metabolite changes during natural and lactic acid bacteria fermentations in pastes of soybeans and soybean–maize blends

    Ng'ong'ola-Manani, Tinna A; Østlie, Hilde Marit; Mwangwela, Agnes M.; Wicklund, Trude

    2014-01-01

    The effect of natural and lactic acid bacteria (LAB) fermentation processes on metabolite changes in pastes of soybeans and soybean–maize blends was studied. Pastes composed of 100% soybeans, 90% soybeans and 10% maize, and 75% soybeans and 25% maize were naturally fermented (NFP), and were fermented by lactic acid bacteria (LFP). LAB fermentation processes were facilitated through back-slopping using a traditional fermented gruel, thobwa as an inoculum. Naturally fermented ...

  4. Kefir Grains Change Fatty Acid Profile of Milk during Fermentation and Storage.

    C P Vieira

    Full Text Available Several studies have reported that lactic acid bacteria may increase the production of free fatty acids by lipolysis of milk fat, though no studies have been found in the literature showing the effect of kefir grains on the composition of fatty acids in milk. In this study the influence of kefir grains from different origins [Rio de Janeiro (AR, Viçosa (AV e Lavras (AD], different time of storage, and different fat content on the fatty acid content of cow milk after fermentation was investigated. Fatty acid composition was determined by gas chromatography. Values were considered significantly different when p<0.05. The highest palmitic acid content, which is antimutagenic compost, was seen in AV grain (36.6g/100g fatty acids, which may have contributed to increasing the antimutagenic potential in fermented milk. Higher monounsaturated fatty acid (25.8 g/100g fatty acids and lower saturated fatty acid (72.7 g/100g fatty acids contents were observed in AV, when compared to other grains, due to higher Δ9-desaturase activity (0.31 that improves the nutritional quality of lipids. Higher oleic acid (25.0 g/100g fatty acids and monounsaturated fatty acid (28.2g/100g fatty acids and lower saturated fatty acid (67.2g/100g fatty acids contents were found in stored kefir relatively to fermented kefir leading to possible increase of antimutagenic and anticarcinogenic potential and improvement of nutritional quality of lipids in storage milk. Only high-lipidic matrix displayed increase polyunsaturated fatty acids after fermentation. These findings open up new areas of study related to optimizing desaturase activity during fermentation in order to obtaining a fermented product with higher nutritional lipid quality.

  5. Urodele p53 tolerates amino acid changes found in p53 variants linked to human cancer

    Villiard Éric

    2007-09-01

    Full Text Available Abstract Background Urodele amphibians like the axolotl are unique among vertebrates in their ability to regenerate and their resistance to develop cancers. It is unknown whether these traits are linked at the molecular level. Results Blocking p53 signaling in axolotls using the p53 inhibitor, pifithrin-α, inhibited limb regeneration and the expression of p53 target genes such as Mdm2 and Gadd45, suggesting a link between tumor suppression and regeneration. To understand this relationship we cloned the p53 gene from axolotl. When comparing its sequence with p53 from other organisms, and more specifically human we observed multiple amino acids changes found in human tumors. Phylogenetic analysis of p53 protein sequences from various species is in general agreement with standard vertebrate phylogeny; however, both mice-like rodents and teleost fishes are fast evolving. This leads to long branch attraction resulting in an artefactual basal emergence of these groups in the phylogenetic tree. It is tempting to assume a correlation between certain life style traits (e.g. lifespan and the evolutionary rate of the corresponding p53 sequences. Functional assays of the axolotl p53 in human or axolotl cells using p53 promoter reporters demonstrated a temperature sensitivity (ts, which was further confirmed by performing colony assays at 37°C. In addition, axolotl p53 was capable of efficient transactivation at the Hmd2 promoter but has moderate activity at the p21 promoter. Endogenous axolotl p53 was activated following UV irradiation (100 j/m2 or treatment with an alkylating agent as measured using serine 15 phosphorylation and the expression of the endogenous p53 target Gadd45. Conclusion Urodele p53 may play a role in regeneration and has evolved to contain multiple amino acid changes predicted to render the human protein defective in tumor suppression. Some of these mutations were probably selected to maintain p53 activity at low temperature. However

  6. Power Electronics Converters for Variable Speed Pump Storage

    Othman Hassan Abdalla

    2012-12-01

    Full Text Available This paper proposed the power electronics solution to obtain variable speed of the variable-speed pump storage The study focused on the types of variable-speed pump storage consists of doubly fed asynchronous machine and power electronics converter. Power Electronics converters used in this model are cycloconverter, two levels, three levels voltage source- converter and H-bridge cascaded eleven levels converters. The total harmonic distortions of rotor currents of Doubly fed asychronous machine and speed change for each type of converters are analyzed. Study explained the H-bridge eleven level converter is the best solution than other types.All simulation models depended on the used of PSIM software program.

  7. Changes in sugars, organic acids and amino acids in medlar (Mespilus germanica L.) during fruit development and maturation

    Glew, R. H.; Ayaz, F. A.; Sanz, C.; VanderJagt, D. J.; Huang, H. S.; Chuang, L. T.; Strnad, Miroslav

    2003-01-01

    Roč. 83, č. 3 (2003), s. 363-369. ISSN 0308-8146 R&D Projects: GA AV ČR IBS5038351 Grant ostatní: Scientific and Research Council of Turkey(TR) TUBITAK-NATO Institutional research plan: CEZ:AV0Z5038910 Keywords : Medlar (Mespilus germanica L.) * Sugar * Organic acid Subject RIV: EF - Botanics Impact factor: 1.204, year: 2003

  8. Changes in oxidation-reduction potential during milk fermentation by wild lactic acid bacteria.

    Morandi, Stefano; Silvetti, Tiziana; Tamburini, Alberto; Brasca, Milena

    2016-08-01

    Oxidation-reduction potential (E h) is a fundamental physicochemical property of lactic acid bacteria that determines the microenvironment during the cheese manufacture and ripening. For this reason the E h is of growing interest in dairy research and the dairy industry. The objective of the study was to perform a comprehensive study on the reduction activity of wild lactic acid bacteria strains collected in different periods (from 1960 to 2012) from Italian dairy products. A total of 709 strains belonging to Lactococcus lactis, Enterococcus durans, E. faecium, E. faecalis and Streptococcus thermophilus species were studied for their reduction activity in milk. Kinetics of milk reduction were characterised by the minimum redox potential (E h7) and time of reaching E h7 (t min), the maximum difference between two measures (Δmax) and the time at which these maximum differences occurred (t*). Broad diversity in kinetic parameters was observed at both species and strain levels. E. faecalis and L. lactis resulted to be the most reducing species, while S. thermophilus was characterised by the lowest reducing power while the greatest heterogeneity was pointed out among E. durans and E. faecium strains. Considering the period of collection (1960-2012) we observed that the more recently isolated strains generally showed less reducing activity. This trend was particularly evident for the species E. durans, E. faecium and L. lactis while an opposite trend was observed in E. faecalis species. Data reported in this research provide new information for a deeper understanding of redox potential changes during milk fermentation due to bacterial growth. Gain knowledge of the redox potential of the LAB cultures could allow a better control and standardisation of cheesemaking process. PMID:27600976

  9. Nitrogen isotopes in ice core nitrate linked to anthropogenic atmospheric acidity change

    Geng, Lei; Alexander, Becky; Cole-Dai, Jihong; Steig, Eric J.; Savarino, Joël; Sofen, Eric D.; Schauer, Andrew J.

    2014-01-01

    Nitrogen stable isotope ratio (δ15N) in Greenland snow nitrate and in North American remote lake sediments has decreased gradually beginning as early as ∼1850 Christian Era. This decrease was attributed to increasing atmospheric deposition of anthropogenic nitrate, reflecting an anthropogenic impact on the global nitrogen cycle, and the impact was thought to be amplified ∼1970. However, our subannually resolved ice core records of δ15N and major ions (e.g., , ) over the last ∼200 y show that the decrease in δ15N is not always associated with increasing concentrations, and the decreasing trend actually leveled off ∼1970. Correlation of δ15N with H+, , and HNO3 concentrations, combined with nitrogen isotope fractionation models, suggests that the δ15N decrease from ∼1850–1970 was mainly caused by an anthropogenic-driven increase in atmospheric acidity through alteration of the gas−particle partitioning of atmospheric nitrate. The concentrations of and also leveled off ∼1970, reflecting the effect of air pollution mitigation strategies in North America on anthropogenic NOx and SO2 emissions. The consequent atmospheric acidity change, as reflected in the ice core record of H+ concentrations, is likely responsible for the leveling off of δ15N ∼1970, which, together with the leveling off of concentrations, suggests a regional mitigation of anthropogenic impact on the nitrogen cycle. Our results highlight the importance of atmospheric processes in controlling δ15N of nitrate and should be considered when using δ15N as a source indicator to study atmospheric flux of nitrate to land surface/ecosystems. PMID:24711383

  10. Temperature- and moisture-dependent phase changes in crystal forms of barbituric acid

    Zencirci, Neslihan; Gstrein, Elisabeth; Langes, Christoph [Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Innsbruck, Innrain 52, 6020 Innsbruck (Austria); Griesser, Ulrich J. [Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Innsbruck, Innrain 52, 6020 Innsbruck (Austria)], E-mail: ulrich.griesser@uibk.ac.at

    2009-03-10

    The dihydrate of barbituric acid (BAc) and its dehydration product, form II were investigated by means of moisture sorption analysis, hot-stage microscopy, differential scanning calorimetry, thermogravimetry, solution calorimetry, IR- and Raman-spectroscopy as well as powder X-ray diffraction. The dihydrate desolvates already at and below 50% relative humidity (RH) at 25 deg. C whereas form II is stable up to 80% RH, where it transforms back to the dihydrate. The thermal dehydration of barbituric acid dihydrate (BAc-H2) is a single step, nucleation controlled process. The peritectic reaction of the hydrate was measured at 77 deg. C and a transformation enthalpy of {delta}{sub trs}H{sub H2-II} = 17.3 kJ mol{sup -1} was calculated for the interconversion between the hydrate and form II. An almost identical value of 17.0 kJ mol{sup -1} was obtained from solution calorimetry in water as solvent ({delta}{sub sol}H{sub H2} = 41.5, {delta}{sub sol}H{sub II} = 24.5 kJ mol{sup -1}). Additionally a high-temperature form (HT-form) of BAc, which is enantiotropically related to form II and unstable at ambient conditions has been characterized. Furthermore, we observed that grinding of BAc with potassium bromide (KBr) induces a tautomeric change. Therefore, IR-spectra recorded with KBr-discs usually display a mixture of tautomers, whereas the IR-spectra of the pure trioxo-form of BAc are obtained if alternative preparation techniques are used.

  11. Deciphering the binding patterns and conformation changes upon the bovine serum albumin-rosmarinic acid complex.

    Peng, Xin; Wang, Xiangchao; Qi, Wei; Huang, Renliang; Su, Rongxin; He, Zhimin

    2015-08-01

    Rosmarinic acid (RA) is an importantly and naturally occurring polyphenol from plants of the mint family with potent biological activities. Here, the in vitro interaction of RA with bovine serum albumin (BSA) has been investigated using various biophysical approaches as well as molecular modeling methods, to ascertain its binding mechanism and conformational changes. The fluorescence results demonstrated that the fluorescence quenching of BSA by RA was mainly the result of the formation of a ground state BSA-RA complex, and BSA had one high affinity RA binding site with a binding constant of 4.18 × 10(4) mol L(-1) at 298 K. Analysis of thermodynamic parameters revealed that hydrophobic and hydrogen bond interactions were the dominant intermolecular force in the complex formation. The primary binding site of RA in BSA (site I) had been identified by site marker competitive experiments. The distance between RA and the tryptophan residue of BSA was evaluated at 3.12 nm based on Förster's theory of non-radiation energy transfer. The UV-vis absorption, synchronous fluorescence, three-dimensional fluorescence, 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescence, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectra confirmed that the conformation and structure of BSA were altered in the presence of RA. Moreover, the nuclear magnetic spectroscopy showed that the aromatic groups of RA took part in the binding reaction during the BSA-RA complexation. In addition, the molecular picture of the interaction mechanism between BSA and RA at the atomic level was well examined by molecular docking and dynamics studies. In brief, RA can bind to BSA with noncovalent bonds in a relatively stable way, and these findings will be beneficial to the functional food research of RA. PMID:26146359

  12. Structural and dynamic changes associated with beneficial engineered single-amino-acid deletion mutations in enhanced green fluorescent protein

    The beneficial engineered single-amino-acid deletion variants EGFPD190Δ and EGFPA227Δ have been studied. Single-amino-acid deletions are a common part of the natural evolutionary landscape but are rarely sampled during protein engineering owing to limited and prejudiced molecular understanding of mutations that shorten the protein backbone. Single-amino-acid deletion variants of enhanced green fluorescent protein (EGFP) have been identified by directed evolution with the beneficial effect of imparting increased cellular fluorescence. Biophysical characterization revealed that increased functional protein production and not changes to the fluorescence parameters was the mechanism that was likely to be responsible. The structure EGFPD190Δ containing a deletion within a loop revealed propagated changes only after the deleted residue. The structure of EGFPA227Δ revealed that a ‘flipping’ mechanism was used to adjust for residue deletion at the end of a β-strand, with amino acids C-terminal to the deletion site repositioning to take the place of the deleted amino acid. In both variants new networks of short-range and long-range interactions are generated while maintaining the integrity of the hydrophobic core. Both deletion variants also displayed significant local and long-range changes in dynamics, as evident by changes in B factors compared with EGFP. Rather than being detrimental, deletion mutations can introduce beneficial structural effects through altering core protein properties, folding and dynamics, as well as function

  13. Structural and dynamic changes associated with beneficial engineered single-amino-acid deletion mutations in enhanced green fluorescent protein

    Arpino, James A. J. [Cardiff University, Park Place, Cardiff CF10 3AT Wales (United Kingdom); Rizkallah, Pierre J., E-mail: rizkallahp@cardiff.ac.uk [Cardiff University, Heath Park, Cardiff CF14 4XN Wales (United Kingdom); Jones, D. Dafydd, E-mail: rizkallahp@cardiff.ac.uk [Cardiff University, Park Place, Cardiff CF10 3AT Wales (United Kingdom)

    2014-08-01

    The beneficial engineered single-amino-acid deletion variants EGFP{sup D190Δ} and EGFP{sup A227Δ} have been studied. Single-amino-acid deletions are a common part of the natural evolutionary landscape but are rarely sampled during protein engineering owing to limited and prejudiced molecular understanding of mutations that shorten the protein backbone. Single-amino-acid deletion variants of enhanced green fluorescent protein (EGFP) have been identified by directed evolution with the beneficial effect of imparting increased cellular fluorescence. Biophysical characterization revealed that increased functional protein production and not changes to the fluorescence parameters was the mechanism that was likely to be responsible. The structure EGFP{sup D190Δ} containing a deletion within a loop revealed propagated changes only after the deleted residue. The structure of EGFP{sup A227Δ} revealed that a ‘flipping’ mechanism was used to adjust for residue deletion at the end of a β-strand, with amino acids C-terminal to the deletion site repositioning to take the place of the deleted amino acid. In both variants new networks of short-range and long-range interactions are generated while maintaining the integrity of the hydrophobic core. Both deletion variants also displayed significant local and long-range changes in dynamics, as evident by changes in B factors compared with EGFP. Rather than being detrimental, deletion mutations can introduce beneficial structural effects through altering core protein properties, folding and dynamics, as well as function.

  14. Radiation damage of proteins in the solid state: changes of amino acid composition in catalase

    Catalase has been irradiated with 100 keV electrons under conditions simulating the hazards of electron microscopic imaging. Amino acid analysis reveals a definite pattern of amino acid destruction which is well correlated with the particular chemical structures of amino acid side chains. This pattern appears to be distinctly different from the sensitivity pattern for monoamino acid systems which is ascribed to intramolecular energy transfer and selective attack of liberated radicals

  15. Lipidomic profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii reveals critical changes in lipid composition in response to acetic acid stress.

    Lina Lindberg

    Full Text Available When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D and Zygosaccharomyces bailii (CBS7555 cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1, while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1 acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP2C 2.2× and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP2C 2.7×, when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to

  16. A Conformation Change in the Extracellular Domain that Accompanies Desensitization of Acid-sensing Ion Channel (ASIC) 3

    Cushman, Kenneth A.; Marsh-Haffner, Josephine; Adelman, John P.; McCleskey, Edwin W.

    2007-01-01

    Acid-sensing ion channels (ASICs) are thought to trigger some forms of acid-induced pain and taste, and to contribute to stroke-induced neural damage. After activation by low extracellular pH, different ASICs undergo desensitization on time scales from 0.1 to 10 s. Consistent with a substantial conformation change, desensitization slows dramatically when temperature drops (Askwith, C.C., C.J. Benson, M.J. Welsh, and P.M. Snyder. 2001. PNAS. 98:6459–6463). The nature of this conformation chang...

  17. Fatty acid esters-based composite phase change materials for thermal energy storage in buildings

    In this study, fatty acid esters-based composite phase change materials (PCMs) for thermal energy storage were prepared by blending erythritol tetrapalmitate (ETP) and erythritol tetrastearate (ETS) with diatomite and expanded perlite (EP). The maximum incorporation percentage for ETP and ETS into diatomite and EP was found to be 57 wt% and 62 wt%, respectively without melted PCM seepage from the composites. The morphologies and compatibilities of the composite PCMs were structurally characterized using scanning electron microscope (SEM) and Fourier transformation infrared (FT–IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by differential scanning calorimetry (DSC) analysis. The DSC analyses results indicated that the composite PCMs were good candidates for building applications in terms of their large latent heat values and suitable phase change temperatures. The thermal cycling test including 1000 melting and freezing cycling showed that composite PCMs had good thermal reliability and chemical stability. TG analysis revealed that the composite PCMs had good thermal durability above their working temperature ranges. Moreover, in order to improve the thermal conductivity of the composite PCMs, the expanded graphite (EG) was added to them at different mass fractions (2%, 5%, and 10%). The best results were obtained for the composite PCMs including 5wt% EG content in terms of the increase in thermal conductivity values and the decrease amount in latent heat capacity. The improvement in thermal conductivity values of ETP/Diatomite, ETS/Diatomite, ETP/EP and ETS/EP were found to be about 68%, 57%, 73% and 75%, respectively. Highlights: ► Fatty acid esters-based composite PCMs were prepared by blending ETP and ETS with diatomite and expanded perlite. ► The composite PCMs were characterized by using SEM, FT–IR, DSC and TG analysis methods. ► The DSC results indicated that the composites PCMs had good thermal

  18. Multilevel push pull power converter

    2007-01-01

    A power converter for converting an input voltage (Vin) into an output voltage (Vout), comprising a first supply potential and a second supply potential established by the input voltage, and at least one primary winding having two terminals, a center tap arranged between the two terminals and...

  19. Catalytic converters in the fireplace

    In addition to selecting the appropriate means of heating and using dry fuel, the amount of harmful emissions contained by flue gases produced by fireplaces can be reduced by technical means. One such option is to use an oxidising catalytic converter. Tests at TTS Institute's Heating Studies Experimental Station have focused on two such converters (dense and coarse) mounted in light-weight iron heating stoves. The ability of the dense catalytic converter to oxidise carbon monoxide gases proved to be good. The concentration of carbon monoxide in the flue gases was reduced by as much as 90 %. Measurements conducted by VTT (Technical Research Centre of Finland) showed that the conversion of other gases, e.g. of methane, was good. The exhaust resistance caused by the dense converter was so great as to necessitate the mounting of a fluegas evacuation fan in the chimney for the purpose of creating sufficient draught. When relying on natural draught, the dense converter requires a chimney of at least 7 metres and a by-pass connection while the fire is being lit. In addition, the converter will have to be constructed to be less dense and this will mean that it's capability to oxidise non-combusted gases will be reduced. The coarse converter did not impair the draught but it's oxidising property was insufficient. With the tests over, the converter was not observed to have become blocked up by impurities

  20. Proposed electromagnetic wave energy converter

    Bailey, R. L.

    1973-01-01

    Device converts wave energy into electric power through array of insulated absorber elements responsive to field of impinging electromagnetic radiation. Device could also serve as solar energy converter that is potentially less expensive and fragile than solar cells, yet substantially more efficient.

  1. Changes in the levels of abscisic acid and its metabolites in excised leaf blades of Xanthium strumarium during and after water stress

    Zeevaart, J.A.D.

    1980-10-01

    The time course of abscisic acid (ABA) accumulation during water stress and of degradation following rehydration was investigated by analyzing the levels of ABA and its metabolites phaseic acid (PA) and alkalihydrolyzable conjugated ABA in excised leaf blades of Xanthium strumarium. Initial purification was by reverse-phase, preparative, high performance liquid chromatography (HPLC) which did not require prior partitioning. ABA and PA were purified further by analytical HPLC with a ..mu..Bondapak-NH/sub 2/ column, and quantified by GLC with an electron capture detector. The ABA content of stressed leaves increased for 4 to 5 hours and then leveled off due to a balance between synthesis and degradation. Since PA accumulated at a constant rate throughout the wilting period, it was concluded that the rate of ABA synthesis decreased after the first 4 to 5 hours stress. Conjugated ABA increased at a low rate during stress. This is interpreted to indicate that free ABA was converted to the conjugated form, rather than the reverse. Following rehydration of wilted leaves, the ABA level immediately ceased increasing; it remained constant for 1 hour and then declined rapidly to the prestress level over a 2- to 3-hour period with a concomitant rise in the PA level. In contrast to the rapid disappearance of ABA after relief of stress, the high PA content of rehydrated leaves declined only slowly. The level of conjugated ABA did not change following rehydration, indicating that conjugation of ABA was irreversible. Detached Xanthium leaves that were subjected to a wilting-recovery-rewilting cycle in darkness responded to the second wilting period by formation of the same amount of ABA as accumulated after the first stress period.

  2. On the Mechanism of Reinitiation of Endogenous Crassulacean Acid Metabolism Rhythm by Temperature Changes.

    Grams, TEE.; Borland, A. M.; Roberts, A.; Griffiths, H.; Beck, F.; Luttge, U.

    1997-04-01

    Under continuous light the endogenous Crassulacean acid metabolism (CAM) rhythm of Kalanchoe daigremontiana Hamet et Perrier de la Bathie disappears at high (>29.0[deg]C) or low (<8.0[deg]C) temperatures. We investigated the reinitiation of rhythmicity when temperature was reduced from above the upper and increased from below the lower threshold level via measurements of (a) short-term changes in carbon-isotope discrimination to illustrate shifts between C3 and C4 carboxylation in vivo, and (b) the malate sensitivity of phosphoenolpyruvate carboxylase (PEPC) in vitro. When the net CO2-exchange rhythm disappears at both temperatures, the instantaneous discrimination indicates low PEPC activity. Leaf malate concentration and osmolarity attain high and low values at low and high temperatures, respectively. After small temperature increases or reductions from the low and high temperatures, respectively, the rhythm is reinitiated, with phases shifted by 180[deg] relative to each other. This can be related to the contrasting low and high leaf malate concentrations due to direct inhibition of PEPC and possibly also of the phosphorylation of PEPC by malate. The experimental results were satisfactorily simulated by a mathematical CAM-cycle model, with temperature acting only on the passive efflux of malate from the vacuole. We stress the important role of the tonoplast in malate compartmentation and of malate itself for the reinitiation and generation of endogenous CAM rhythmicity. PMID:12223675

  3. Physical changes of poly(lactic acid) induced by water sorption

    Pantani, Roberto; De Santis, Felice

    2015-12-01

    One of the main limits to the use of Poly(Lactic Acid), PLA, is its extreme sensitivity to moisture. The objective of this work is to study the physical changes induced by water sorption on a commercial PLA grade. To this goal, samples of PLA having thickness of about 400 µm, obtained by compression molding, were put into contact with water at 58 °C. The samples were partially immersed in water in a closed and mixed vessel, so that the lower part was in contact with liquid water whereas the upper part was in contact with air with a relative humidity of 100%. The opacity of the samples, their crystallinity degree, their density and molecular weight were monitored during time. It was found that the samples became white and opaque after a few hours, crystallinity reached an equilibrium value after about 48 h. Density was found to decrease with time, thus suggesting that the whitening was due to crazing. Surprisingly, it was found that the mentioned phenomena are more evident for the samples immersed in water than for those surrounded by a 100% RH atmosphere.

  4. Evidence for Status Epilepticus and Pro-Inflammatory Changes after Intranasal Kainic Acid Administration in Mice.

    Mounira Sabilallah

    Full Text Available Kainic acid (KA is routinely used to elicit status epilepticus (SE and epileptogenesis. Among the available KA administration protocols, intranasal instillation (IN remains understudied. Dosages of KA were instilled IN in mice. Racine Scale and Video-EEG were used to assess and quantify SE onset. Time spent in SE and spike activity was quantified for each animal and confirmed by power spectrum analysis. Immunohistochemistry and qPCR were performed to define brain inflammation occurring after SE, including activated microglial phenotypes. Long term video-EEG recording was also performed. Titration of IN KA showed that a dose of 30 mg/kg was associated with low mortality while eliciting SE. IN KA provoked at least one behavioral and electrographic SE in the majority of the mice (>90%. Behavioral and EEG SE were accompanied by a rapid and persistent microglial-astrocytic cell activation and hippocampal neurodegeneration. Specifically, microglial modifications involved both pro- (M1 and anti-inflammatory (M2 genes. Our initial long-term video-EEG exploration conducted using a small cohort of mice indicated the appearance of spike activity or SE. Our study demonstrated that induction of SE is attainable using IN KA in mice. Typical pro-inflammatory brain changes were observed in this model after SE, supporting disease pathophysiology. Our results are in favor of the further development of IN KA as a means to study seizure disorders. A possibility for tailoring this model to drug testing or to study mechanisms of disease is offered.

  5. Effect of Salicylic Acid on Salinity-induced Changes in Brassica juncea

    Mohammad Yusuf; Syed Aiman Hasan; Barket Ali; Shamsul Hayat; Qazi Fariduddin; Aqil Ahmad

    2008-01-01

    Seeds of Indian mustard (Brassica juncea (L.) Czern.et Coss.) were exposed to 0,50,100 and 150 mmol/L NaCl for 8h and seeds were sown in an earthen pot.These stressed seedlings were subsequently sprayed with 10 μrnol/L salicylic acid (SA) at 30 d and were sampled at 60 d to assess the changes in growth,photosynthesis and antioxidant enzymes.The seedlings raised from the seeds treated with NaCl had significantly reduced growth and the activities of carbonic anhydrase,nitrate reductase and photosynthesis,and the decrease was proportional to the increase in NaCl concentration.However,the antioxidant enzymes (catalase,peroxidase and superoxide dismutase) and proline content was enhanced in response to NaCl and/or SA treatment,where their interaction had an additive effect.Moreover,the toxic effects generated by the lower concentration of NaCl (50 mmol/L) were completely overcome by the application of SA.It was,therefore,concluded that SA ameliorated the stress generated by NaCl through the alleviated antioxidant system.

  6. Developmental changes of glutamate acid decarboxylase 67 in mouse brain after hypoxia ischemia

    Fa-Lin XU; Chang-Lian ZHU; Xiao-Yang WANG

    2006-01-01

    Objective To study the developmental changes of glutamic acid decarboxylase-67 ( GAD-67, a GABA synthetic enzyme) in normal and hypoxic ischemic (HI) brain. Methods C57/BL6 mice on postnatal day (P) 5, 9, 21and 60, corresponding developmentally to premature, term, juvenile and adult human brain were investigated by using both Western blot and immunohistochemistry methods either in normal condition or after hypoxic ischemic insult. Results The immunoreactivity of GAD67 was up regulated with brain development and significant difference was seen between mature (P21, P60) and immature (P5, P9) brain. GAD67 immunoreactivity decreased in the ipsilateral hemisphere in all the ages after hypoxia ischemia (HI) insult, but, significant decrease was only seen in the immature brain. Double labeling of GAD67 and cell death marker, TUNEL, in the cortex at 8h post-HI in the P9 mice showed that (15.6 ±7.0)%TUNEL positive cells were GAD67 positive which was higher than that of P60 mice. Conclusion These data suggest that GABAergic neurons in immature brain were more vulnerable to HI insult than that of mature brain.

  7. Identification of Dynamic Changes in Proteins Associated with the Cellular Cytoskeleton after Exposure to Okadaic Acid

    Peter Roepstorff

    2013-05-01

    Full Text Available Exposure of cells to the diarrhetic shellfish poison, okadaic acid, leads to a dramatic reorganization of cytoskeletal architecture and loss of cell-cell contact. When cells are exposed to high concentrations of okadaic acid (100–500 nM, the morphological rearrangement is followed by apoptotic cell death. Okadaic acid inhibits the broad acting Ser/Thr protein phosphatases 1 and 2A, which results in hyperphosphorylation of a large number of proteins. Some of these hyperphosphorylated proteins are most likely key players in the reorganization of the cell morphology induced by okadaic acid. We wanted to identify these phosphoproteins and searched for them in the cellular lipid rafts, which have been found to contain proteins that regulate cytoskeletal dynamics and cell adhesion. By using stable isotope labeling by amino acids in cell culture cells treated with okadaic acid (400 nM could be combined with control cells before the isolation of lipid rafts. Protein phosphorylation events and translocations induced by okadaic acid were identified by mass spectrometry. Okadaic acid was shown to regulate the phosphorylation status and location of proteins associated with the actin cytoskeleton, microtubules and cell adhesion structures. A large number of these okadaic acid-regulated proteins have previously also been shown to be similarly regulated prior to cell proliferation and migration. Our results suggest that okadaic acid activates general cell signaling pathways that induce breakdown of the cortical actin cytoskeleton and cell detachment.

  8. Spatial Patterns and Temperature Predictions of Tuna Fatty Acids: Tracing Essential Nutrients and Changes in Primary Producers.

    Heidi R Pethybridge

    Full Text Available Fatty acids are among the least understood nutrients in marine environments, despite their profile as key energy components of food webs and that they are essential to all life forms. Presented here is a novel approach to predict the spatial-temporal distributions of fatty acids in marine resources using generalized additive mixed models. Fatty acid tracers (FAT of key primary producers, nutritional condition indices and concentrations of two essential long-chain (≥C20 omega-3 fatty acids (EFA measured in muscle of albacore tuna, Thunnus alalunga, sampled in the south-west Pacific Ocean were response variables. Predictive variables were: location, time, sea surface temperature (SST and chlorophyll-a (Chla, and phytoplankton biomass at time of catch and curved fork length. The best model fit for all fatty acid parameters included fish length and SST. The first oceanographic contour maps of EFA and FAT (FATscapes were produced and demonstrated clear geographical gradients in the study region. Predicted changes in all fatty acid parameters reflected shifts in the size-structure of dominant primary producers. Model projections show that the supply and availability of EFA are likely to be negatively affected by increases in SST especially in temperate waters where a 12% reduction in both total fatty acid content and EFA proportions are predicted. Such changes will have large implications for the availability of energy and associated health benefits to high-order consumers. Results convey new concerns on impacts of projected climate change on fish-derived EFA in marine systems.

  9. Spatial Patterns and Temperature Predictions of Tuna Fatty Acids: Tracing Essential Nutrients and Changes in Primary Producers.

    Pethybridge, Heidi R; Parrish, Christopher C; Morrongiello, John; Young, Jock W; Farley, Jessica H; Gunasekera, Rasanthi M; Nichols, Peter D

    2015-01-01

    Fatty acids are among the least understood nutrients in marine environments, despite their profile as key energy components of food webs and that they are essential to all life forms. Presented here is a novel approach to predict the spatial-temporal distributions of fatty acids in marine resources using generalized additive mixed models. Fatty acid tracers (FAT) of key primary producers, nutritional condition indices and concentrations of two essential long-chain (≥C20) omega-3 fatty acids (EFA) measured in muscle of albacore tuna, Thunnus alalunga, sampled in the south-west Pacific Ocean were response variables. Predictive variables were: location, time, sea surface temperature (SST) and chlorophyll-a (Chla), and phytoplankton biomass at time of catch and curved fork length. The best model fit for all fatty acid parameters included fish length and SST. The first oceanographic contour maps of EFA and FAT (FATscapes) were produced and demonstrated clear geographical gradients in the study region. Predicted changes in all fatty acid parameters reflected shifts in the size-structure of dominant primary producers. Model projections show that the supply and availability of EFA are likely to be negatively affected by increases in SST especially in temperate waters where a 12% reduction in both total fatty acid content and EFA proportions are predicted. Such changes will have large implications for the availability of energy and associated health benefits to high-order consumers. Results convey new concerns on impacts of projected climate change on fish-derived EFA in marine systems. PMID:26135308

  10. Radiation tolerant power converter controls

    Todd, B; King, Q; Uznanski, S

    2012-01-01

    The Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is the world's most powerful particle collider. The LHC has several thousand magnets, both warm and super-conducting, which are supplied with current by power converters. Each converter is controlled by a purpose-built electronic module called a Function Generator Controller (FGC). The FGC allows remote control of the power converter and forms the central part of a closed-loop control system where the power converter voltage is set, based on the converter output current and magnet-circuit characteristics. Some power converters and FGCs are located in areas which are exposed to beam-induced radiation. There are numerous radiation induced effects, some of which lead to a loss of control of the power converter, having a direct impact upon the accelerator's availability. Following the first long shut down (LS1), the LHC will be able to run with higher intensity beams and higher beam energy. This is expected to lead to signifi...

  11. DETECTION OF EARLY GENE EXPRESSION CHANGES BY DIFFERENTIAL DISPLAY IN THE LIVERS OF MICE EXPOSED TO DICHLOROACETIC ACID

    Dichloroacetic acid (DCA) is a major by-product of water disinfection by chlorination. Several studies have demonstrated the hepatocarcinogenicity of DCA in mice when administered in drinking water. The mechanism of DCA carcinogenicity is not clear and we speculate that changes...

  12. Postdelivery changes in maternal and infant erythrocyte fatty acids in 3 populations differing in fresh water fish intakes

    Kuipers, Remko S.; Luxwolda, Martine F.; Sango, Wicklif S.; Kwesigabo, Gideon; Dijck-Brouwer, D. A. Janneke; Muskiet, Frits A. J.

    2011-01-01

    Introduction: Long-chain polyunsaturated (LCP) fatty acids (FA) are important during infant development. Mother-to-infant FA-transport occurs at the expense of the maternal status. Maternal and infant FA-status change rapidly after delivery. Methods: Comparison of maternal (mRBC) and infant erythroc

  13. Pulse-width modulated DC-DC power converters

    Kazimierczuk, Marian K

    2008-01-01

    This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

  14. Bovine serum sialic acid: age-related changes in type and content.

    Sherblom, A P; Bharathan, S; Hall, P J; Smagula, R M; Moody, C E; Anderson, G W

    1988-01-01

    1. The sialic acid content of newborn calf serum (4.8 mumol/ml) is approx. 3-fold higher than that of mature animals (1.4 mumol/ml) and decreases to 2.4 mumol/ml at 20 days of age. Colostrum-fed and colostrum-deprived calves have similar levels of sialic acid from birth to 14 days of age. 2. The high level of sialic acid in newborn calf serum is due predominantly to N-acetylneuraminic acid, since this sialic acid accounts for 93% of the total and since less than 5% of the sialic acid is O-acetylated. 3. Comparison of day 0 and day 20 serum by gel filtration and by SDS polyacrylamide gel electrophoresis demonstrates that the increase in sialic acid is associated with increased production and/or sialylation of components with MW of 45-60 kDa. 4. A high percentage (64%) of the sialic acid in newborn calf serum is detected with the lipid-linked sialic acid assay, relative to 20 day old (25%) or mature (18%) animals. 5. This indicates that the glycoproteins of newborn calf serum are more efficiently extracted under the conditions of this assay than glycoproteins of mature serum. PMID:3248673

  15. Monthly Changes of Glycogen, Lipid and Free Amino Acid of Oyster

    ZHANG Zhicui; XUE Changhu; GAO Xin; LI Zhaojie; WANG Qi

    2006-01-01

    Monthly difference of the chemical composition of oyster cultured along the eastern coast of Shandong Province was analyzed.The components analyzed included glycogen, fatty acid and free amino acid (FAA).The content of glycogen was high in January and March (2.89 and 2.82 g(100 g)- 1 on average, respectively) and low in October (2.07 g(100 g)- 1 on average).The low content of neutral lipids in October reflected a relatively poor nutritional value of oyster (1.42 g(100 g) -1 on average).The main fatty acids of oyster were palmitic acid(16:0),oleic acid(18:1),eicosapentaenoic acid (EPA,20:5w-3) and docosahexaenoic acid(DHA,22:6w-3).The major FAAs of oyster were Taurine,Glutamicacid,Glycin,Alanine, Arginine and Proline.Taurine was the most abundant FAA with its content ranging from 603 mg(100 g)- 1 to 1139 mg(100 g) -1.The high contents of glycogen, polyunsaturated fatty acid and FAA showed that oyster cultured along the eastern coast of Shandong Province was nutritionally good in January and March.

  16. Monthly changes of glycogen, lipid and free amino acid of oyster

    Zhicui, Zhang; Changhu, Xue; Xin, Gao; Zhaojie, Li; Qi, Wang

    2006-07-01

    Monthly difference of the chemical composition of oyster cultured along the eastern coast of Shandong Province was analyzed. The components analyzed included glycogen, fatty acid and free amino acid (FAA). The content of glycogen was high in January and March (2.89 and 2.82 g(100g)-1 on average, respectively) and low in October (2.07 g(100g)-1 on avarage). The low content of neutral lipids in October reflected a relatively poor nutritional value of oyster (1.42 g(100 g)-1 on average). The main fatty acids of oyster were palmitic acid (16:0), oleic acid (18:1), eicosapentaenoic acid (EPA, 20: 5ω-3) and docosahexaenoic acid (DHA, 22:6ω-3). The major FAAs of oyster were Taurine, Glutamicacid, Glycin, Alanine, Arginine and Proline. Taurine was the most abundant FAA with its content ranging from 603 mg (100g)-1 to 1139 mg(100g)-1. The high contents of glycogen, polyunsaturated fatty acid and FAA showed that oyster cultured along the eastern coast of Shandong Province was nutritionally good in January and March.

  17. [Changes, induced by certain flavonoids, of the hypotensive effects of arachidonic acid].

    Damas, J; Mousty, J C; Lecomte, J

    1977-01-01

    In the rat, silybine and Z 12007, a derivative of rutoside, increase the vasodepressive activities of arachidonic acid, a prostaglandin precursor. They reduce the activity of PGE2. Quercetine also increases the hypotensive action of arachidonic acid. These three flavonoids are supposed to increase the prostaglandin biosynthesis. PMID:143326

  18. Identification of dynamic changes in proteins associated with the cellular cytoskeleton after exposure to okadaic acid

    Opsahl, Jill A; Ljostveit, Sonja; Solstad, Therese;

    2013-01-01

    Exposure of cells to the diarrhetic shellfish poison, okadaic acid, leads to a dramatic reorganization of cytoskeletal architecture and loss of cell-cell contact. When cells are exposed to high concentrations of okadaic acid (100-500 nM), the morphological rearrangement is followed by apoptotic...

  19. Change in the amino acid composition of calf skin collagen after. gamma. -irradiation in aqueous solution

    Duzhenkova, N.A.; Savich, A.V. (Institut Biofiziki, Moscow (USSR))

    A study was made of the amino acid composition of calf skin collagen after ..gamma..-irradiation (/sup 60/Co) of 2.5x10/sup -6/ M aerated aqueous protein solution within the dose range from 30 to 2000 Gy. The radiosensitivity of amino acid residues was compared.

  20. Laser system with wavelength converter

    2012-01-01

    The present invention relates to an apparatus comprising a diode laser (10) providing radiation in a first wavelength interval, a radiation conversion unit (12) having an input and an output, the radiation converter configured to receive the radiation in the first wavelength interval from the diode...... laser at the input, the radiation conversion unit configured to convert the radiation in the first wavelength interval to radiation in a second wavelength interval and the output configured to output the converted radiation, the second wavelength interval having one end point outside the first...... wavelength interval. Further, the invention relates to a method of optically pumping a target laser (14) in a laser system, the laser system comprising a laser source providing radiation at a first frequency, the laser source being optically connected to an input of a frequency converter, the frequency...

  1. Time-to-digital converters

    Henzler, Stephan

    2010-01-01

    This text covers the fundamentals of time-to-digital converters on analog and digital conversion principles. It includes a theoretical investigation into quantization, linearity, noise and variability, and it details a range of advanced TDC architectures.

  2. Changes in plasma osmolality, cortisol and amino acid levels of tongue sole ( Cynoglossus semilaevis) at different salinities

    Wang, Guodong; Xu, Kefeng; Tian, Xiangli; Dong, Shuanglin; Fang, Ziheng

    2015-10-01

    A serial of salinity transferring treatments were performed to investigate the osmoregulation of tongue sole ( Cynoglossus semilaevis). Juvenile tongue sole were directly transferred from a salinity of 30 to 0, 10, 20, 30, 40 and 50. Blood sampling was performed for each treatment after 0, 1, 6 and 12 h, as well as after 1, 2, 4, 8, 16 and 32 d. The plasma osmolality, cortisol and free amino acids were assessed. Under the experimental conditions, no fish died after acute salinity transfer. The plasma cortisol level increased 1 h after the abrupt transfer from a salinity of 30 to that of 0, 40 and 50, and decreased from 6 h to 8 d after transfer. Similar trends were observed in the changes of plasma osmolality. The plasma free amino acids concentration showed a `U-shaped' relationship with salinity after being transferred to different salinities for 4 days. More obvious changes of plasma free amino acid concentration occurred under hyper-osmotic conditions than under hypo-osmotic conditions. The concentrations of valine, isoleucine, lysine, glutamic acid, glycine, proline and taurine increased with rising salinity. The plasma levels of threonine, leucine, arginine, serine, and alanine showed a `U-shaped' relationship with salinity. The results of this study suggested that free amino acids might have important effects on osmotic acclimation in tongue sole.

  3. Changes in growth, photosynthetic activities, biochemical parameters and amino acid profile of Thompson Seedless grapes (Vitis vinifera L.).

    Somkuwar, R G; Bahetwar, Anita; Khan, I; Satisha, J; Ramteke, S D; Itroutwar, Prerna; Bhongale, Aarti; Oulkar, Dashrath

    2014-11-01

    The study on photosynthetic activity and biochemical parameters in Thompson Seedless grapes grafted on Dog Ridge rootstock and its impact on growth, yield and amino acid profile at various stages of berry development was conducted during the year 2012-2013. Leaf and berry samples from ten year old vines of Thompson Seedless were collected at different growth and berry developmental stages. The analysis showed difference in photosynthetic activity, biochemical parameters and amino acid status with the changes in berry development stage. Higher photosynthetic rate of 17.39 umol cm(-2) s(-1) was recorded during 3-4mm berry size and the lowest (10.08 umol cm(-2) s(-1)) was recorded during the veraison stage. The photosynthetic activity showed gradual decrease with the onset of harvest while the different biochemical parameters showed increase and decrease from one stage to another in both berry and leaves. Changes in photosynthetic activity and biochemical parameters thereby affected the growth, yield and amino acid content of the berry. Positive correlation of leaf area and photosynthetic rate was recorded during the period of study. Reducing sugar (352.25 mg g(-1)) and total carbohydrate (132.52 mg g(-1)) was more in berries as compared to leaf. Amino acid profile showed variations in different stages of berry development. Marked variations in photosynthetic as well as biochemical and amino acid content at various berry development stages was recorded and thereby its cumulative effect on the development of fruit quality. PMID:25522520

  4. Changes in optical density, amino acid composition, and fluorescence of papain inactivated by hydroxyl radicals and hydrogen peroxide

    Chromatography of irradiated papain on an affinity column with the Gly-Gly-Tyr(Bzl)-Arg inhibitor peptide gave rise to three clearly resolved peaks. The first one was relatively small and contained completely inactive nonreparable enzyme, which appeared to have suffered a massive conformational change or loss of several binding sites. The second contained the inactive sulfenic acid derivative, which can be reactivated with cysteine. The third peak was composed of nonrepairable enzyme as well as some repairable enzyme and some fully active papain. Changes in absorbance and amino acid analysis established a significant loss of tyrosine residues, while tryptophan destruction appeared to be insignificant up to 10 krad. Fluorescence measurements indicated changes in the active-site region, which are probably largely due to the inactivating modification of the Cys-25 sulfhydryl group, for which evidence has already been reported

  5. Influence of humic acid imposed changes of ferrihydrite aggregation on microbial Fe(III) reduction

    Amstaetter, Katja; Borch, Thomas; Kappler, Andreas

    2012-05-01

    Microbial reduction of Fe(III) minerals at neutral pH is faced by the problem of electron transfer from the cells to the solid-phase electron acceptor and is thought to require either direct cell-mineral contact, the presence of Fe(III)-chelators or the presence of electron shuttles, e.g. dissolved or solid-phase humic substances (HS). In this study we investigated to which extent the ratio of Pahokee Peat Humic Acids (HA) to ferrihydrite in the presence and absence of phosphate influences rates of Fe(III) reduction by Shewanella oneidensis MR-1 and the identity of the minerals formed. We found that phosphate generally decreased reduction rates by sorption to the ferrihydrite and surface site blocking. In the presence of low ferrihydrite concentrations (5 mM), the addition of HA helped to overcome this inhibiting effect by functioning as electron shuttle between cells and the ferrihydrite. In contrast, at high ferrihydrite concentrations (30 mM), the addition of HA did not lead to an increase but rather to a decrease in reduction rates. Confocal laser scanning microscopy images and ferrihydrite sedimentation behaviour suggest that the extent of ferrihydrite surface coating by HA influences the aggregation of the ferrihydrite particles and thereby their accessibility for Fe(III)-reducing bacteria. We further conclude that in presence of dissolved HA, iron reduction is stimulated through electron shuttling while in the presence of only sorbed HA, no stimulation by electron shuttling takes place. In presence of phosphate the stimulation effect did not occur until a minimum concentration of 10 mg/l of dissolved HA was reached followed by increasing Fe(III) reduction rates up to dissolved HA concentrations of approximately 240 mg/l above which the electron shuttling effect ceased. Not only Fe(III) reduction rates but also the mineral products changed in the presence of HA. Sequential extraction, XRD and 57Fe-Mössbauer spectroscopy showed that crystallinity and grain

  6. Boron nitride converted carbon fiber

    Rousseas, Michael; Mickelson, William; Zettl, Alexander K.

    2016-04-05

    This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

  7. PHASE CONVERTER OF COMPOSING DISPLACEMENT

    SMIRNOV YU.S.; Lysov, A. N.; E.V. Yurasova; SAFRONOV V.V.; VSTAVSKAYA E.V.

    2016-01-01

    Minimax strategy of mechatronic converters efficiency improving relative to error decrease with velocity increase at the same time provides common dataware level rise. The analysis of usage possibilities of different type position transducers (PT) gives the advantages of resolvers. The subsequent processing of their output signals is performed by “Resolver-to-Digit” Converter (RDC) which provides displacement digital equivalent and digital or analog signals specifying its velocity and acceler...

  8. A conformation change in the extracellular domain that accompanies desensitization of acid-sensing ion channel (ASIC) 3.

    Cushman, Kenneth A; Marsh-Haffner, Josephine; Adelman, John P; McCleskey, Edwin W

    2007-04-01

    Acid-sensing ion channels (ASICs) are thought to trigger some forms of acid-induced pain and taste, and to contribute to stroke-induced neural damage. After activation by low extracellular pH, different ASICs undergo desensitization on time scales from 0.1 to 10 s. Consistent with a substantial conformation change, desensitization slows dramatically when temperature drops (Askwith, C.C., C.J. Benson, M.J. Welsh, and P.M. Snyder. 2001. PNAS. 98:6459-6463). The nature of this conformation change is unknown, but two studies showed that desensitization rate is altered by mutations on or near the first transmembrane domain (TM1) (Coric, T., P. Zhang, N. Todorovic, and C.M. Canessa. 2003. J. Biol. Chem. 278:45240-45247; Pfister, Y., I. Gautschi, A.-N. Takeda, M. van Bemmelen, S. Kellenberger, and L. Schild. 2006. J. Biol. Chem. 281:11787-11791). Here we show evidence of a specific conformation change associated with desensitization. When mutated from glutamate to cysteine, residue 79, which is some 20 amino acids extracellular to TM1, can be altered by cysteine-modifying reagents when the channel is closed, but not when it is desensitized; thus, desensitization appears to conceal the residue from the extracellular medium. D78 and E79 are a pair of adjacent acidic amino acids that are highly conserved in ASICs yet absent from epithelial Na(+) channels, their acid-insensitive relatives. Despite large effects on desensitization by mutations at positions 78 and 79-including a shift to 10-fold lower proton concentration with the E79A mutant-there are not significant effects on activation. PMID:17389250

  9. FREQUENCY CONVERTERS WITH IMPROVED PERFORMANCE

    Grigorash O. V.

    2016-01-01

    Full Text Available In the autonomous power supply systems there are widely used frequency converters that are able to simultaneously increase or decrease the frequency of the current and voltage stabilizing power supply. These positive properties of frequency converters can improve the operational and technical characteristics of the autonomous power supply system in the complex. The article suggests a functional diagram of a frequency converter performed on reversible rectifiers. We have presented timing diagrams illustrating the principle of its operation. The article also deals with two functional scheme of direct frequency converters executed on single-phase, threephase transformer with a rotating magnetic field. The principle of operation of these schemes has been also discussed in the timing diagrams. The proposed technical solutions for frequency converters contain a smaller amount of power electronic devices that make it possible, thereby reducing the level of electromagnetic interference, increase the efficiency and reliability of performance inverters. The considered scheme of frequency converters, can improve the technical characteristics of the autonomous power supply systems in the complex. We can significantly improve the performance of power systems through the use of modular aggregating principle of the basic functional units of an autonomous system

  10. Current status of converter steelmaking

    Oghbasialasie, H.; Holappa, L.

    1995-12-31

    This literature work is mainly focusing on the mechanisms of modern converter steelmaking and related with the evaluation of converter technology applied during the last decades and further to the future. The history of steelmaking has been briefly reviewed from bloomeries and early-steelmaking processes to the progress of modern converter process. The pneumatic converter processes were developed in the 1850`s and thereafter the basis for the rapid growth of steel industries was established for the next 100 years. The world production of steel has not continuously grown but fluctuating quite much. It reached 723 Mt in 1994. The production is believed to grow the forecast for the year 2003 being approximately 800 Mt. Electric arc furnace production is estimated to reach 280 Mt by 2003, and BOFIOH will reach 520 Mt by 2003. The current status of the converter steelmaking process is briefly described both on its theoretical bases and practical technological progresses. Developments which significantly improve the process are briefly discussed. Several more recent developments such as combined oxygen blowing process, increased scrap melting, post combustion and hot metal pretreatment are discussed. The future progress will be in further development of these process characteristics as well as in eventual emerging of the continuous converter process. (author)

  11. A conceptual framework: Redefining forest soil's critical acid loads under a changing climate

    McNulty, Steven G., E-mail: steve_mcnulty@ncsu.ed [USDA Forest Service, Eastern Forests Environmental Assessment Threats Center, Southern Global Change Program, 920 Main Campus Dr. Suite 300, Raleigh, NC 27606 (United States); Boggs, Johnny L. [USDA Forest Service, Eastern Forests Environmental Assessment Threats Center, Southern Global Change Program, 920 Main Campus Dr. Suite 300, Raleigh, NC 27606 (United States)

    2010-06-15

    Federal agencies of several nations have or are currently developing guidelines for critical forest soil acid loads. These guidelines are used to establish regulations designed to maintain atmospheric acid inputs below levels shown to damage forests and streams. Traditionally, when the critical soil acid load exceeds the amount of acid that the ecosystem can absorb, it is believed to potentially impair forest health. The excess over the critical soil acid load is termed the exceedance, and the larger the exceedance, the greater the risk of ecosystem damage. This definition of critical soil acid load applies to exposure of the soil to a single, long-term pollutant (i.e., acidic deposition). However, ecosystems can be simultaneously under multiple ecosystem stresses and a single critical soil acid load level may not accurately reflect ecosystem health risk when subjected to multiple, episodic environmental stress. For example, the Appalachian Mountains of western North Carolina receive some of the highest rates of acidic deposition in the eastern United States, but these levels are considered to be below the critical acid load (CAL) that would cause forest damage. However, the area experienced a moderate three-year drought from 1999 to 2002, and in 2001 red spruce (Picea rubens Sarg.) trees in the area began to die in large numbers. The initial survey indicated that the affected trees were killed by the southern pine beetle (Dendroctonus frontalis Zimm.). This insect is not normally successful at colonizing these tree species because the trees produce large amounts of oleoresin that exclude the boring beetles. Subsequent investigations revealed that long-term acid deposition may have altered red spruce forest structure and function. There is some evidence that elevated acid deposition (particularly nitrogen) reduced tree water uptake potential, oleoresin production, and caused the trees to become more susceptible to insect colonization during the drought period

  12. A conceptual framework: Redefining forest soil's critical acid loads under a changing climate

    Federal agencies of several nations have or are currently developing guidelines for critical forest soil acid loads. These guidelines are used to establish regulations designed to maintain atmospheric acid inputs below levels shown to damage forests and streams. Traditionally, when the critical soil acid load exceeds the amount of acid that the ecosystem can absorb, it is believed to potentially impair forest health. The excess over the critical soil acid load is termed the exceedance, and the larger the exceedance, the greater the risk of ecosystem damage. This definition of critical soil acid load applies to exposure of the soil to a single, long-term pollutant (i.e., acidic deposition). However, ecosystems can be simultaneously under multiple ecosystem stresses and a single critical soil acid load level may not accurately reflect ecosystem health risk when subjected to multiple, episodic environmental stress. For example, the Appalachian Mountains of western North Carolina receive some of the highest rates of acidic deposition in the eastern United States, but these levels are considered to be below the critical acid load (CAL) that would cause forest damage. However, the area experienced a moderate three-year drought from 1999 to 2002, and in 2001 red spruce (Picea rubens Sarg.) trees in the area began to die in large numbers. The initial survey indicated that the affected trees were killed by the southern pine beetle (Dendroctonus frontalis Zimm.). This insect is not normally successful at colonizing these tree species because the trees produce large amounts of oleoresin that exclude the boring beetles. Subsequent investigations revealed that long-term acid deposition may have altered red spruce forest structure and function. There is some evidence that elevated acid deposition (particularly nitrogen) reduced tree water uptake potential, oleoresin production, and caused the trees to become more susceptible to insect colonization during the drought period

  13. Metabolic changes of salicylic acid-elicited Catharanthus roseus cell suspension cultures monitored by NMR-based metabolomics

    Mustafa, Natali Rianika; Kim, Hye Kyong; Choi, Young Hae; Verpoorte, Robert

    2009-01-01

    The effect of salicylic acid (SA) on the metabolic profile of Catharanthus roseus suspension cells throughout a time course (0, 6, 12, 24, 48 and 72 h after treatment) was investigated using NMR spectroscopy and multivariate data analysis. When compared to control cell lines, SA-treated cells showed a high level of sugars (glucose and sucrose) up to 48 h after treatment, followed by a dynamic change in amino acids, phenylpropanoids, and tryptamine. Additionally, one compound—2,5-dihydroxybenz...

  14. A new configuration for multilevel converters with diode clamped topology

    Nami, A.; Zare, F.; Ledwich, G.; Ghosh, A.; Blaabjerg, Frede

    points in this type of converter is dc-voltage control. In this paper, a novel multi output dc-dc converter connected to a diode clamped topology is presented. This converter, for a given duty cycles, is able to regulate the capacitor voltage to provide an appropriate input voltage for NPC regardless of......Due to the increased use of renewable energy and power elctronic applications, more multilevel converters (MLC) are developed. A Neutral Point Clamped (NPC) inverter is one of the most used multilevel topologies for wind turbine (WT) and photovoltaic (PV) applications. One of the most crucial...... load changes which can avoid neutral point balancing problem in such converters. In addition, the presented topology is suitable for renewable energy systems to boost the low rectified output-voltage. In order to verify the proposed topology, steady state analysis, modelling and simulations are carried...

  15. An Innovative Reconfigurable Integrated Converter Topology Suitable for Distributed Generation

    Renato Rizzo

    2012-09-01

    Full Text Available The electricity market and environmental concerns, with wide utilization of renewable sources, have improved the diffusion of distributed generation units changing the operations of distribution grids from passive networks to microgrids. A microgrid includes a cluster of electrical loads, energy storage devices and microsources, which provide both power and heat to their local area. A microgrid has usually one connection point to the utility grid through power electronic converters placed at customers’ sites. This paper analyses a Reconfigurable Integrated Converter (RIC used for a domestic microgrid with inputs from the AC mains and photovoltaic arrays, and two DC outputs at different voltage levels. A RIC as a dual-boost DC-DC converter is proposed, modelled and analysed in the paper. The advantages of such a topology in comparison with traditional boost converters are outlined. Reported simulations results give evidence on the controllability of this converter and the capability of achieving the desired voltage outputs with reduced ripple.

  16. Impedance Coordinative Control for Cascaded Converter in Bidirectional Application

    Tian, Yanjun; Deng, Fujin; Chen, Zhe;

    2015-01-01

    Two stage cascaded converters are widely used in bidirectional applications, but the negative impedance may cause system instability. Actually the impedance interaction is much different between forward power flow and reversed power flow, which will introduce more uncertainty to the system...... difference between forward and reversed power flow. This paper addresses the analysis with the topology of cascaded dual-active-bridge converter (DAB) with inverter, and the proposed control method can also be implemented in unidirectional applications and other general cascaded converter system. The...... stability. This paper proposes a control method for the constant power controlled converter in cascaded system, and consequently it can change the negative impedance of constant power converter into resistive impedance, which will improve the cascaded system stability, as well as merge the impedance...

  17. Design of Monolithic Integrator for Strain-to-Frequency Converter

    Tuan Mohd. Khairi Tuan Mat

    2012-01-01

    Full Text Available Strain-to-Frequency converter (SFC is a one of the analog conditioner tools that converts any strain signal to the frequency signal. The basic concept of SFC is by detecting any changing of strains, then converting the strain to the voltage signal and converting the voltage signal to the frequency signal. This tool consists of 3 main  components which are strain gauge, differential integrator and comparator. This paper presents the designing and analysis of monolithic integrator that to be used in the Strain-toFrequency converter. The primary goal is to design and simulate the performance of monolithic integrator for SFC using GATEWAY Silvaco Electronic Design Automation (S EDA tools and EXPERT software. The performances of SFC using the designed monolithic integrator are also investigated.

  18. Design Of Converter For Low Power Photovoltaic Conversion System

    SWAPNIL ZADEY, SUBROTO DUTT

    2013-06-01

    Full Text Available The solar energy conversion system is an alternative for conventional power generating system. It has no running cost due to freely available and non polluting solar radiations. The voltage which is available from solar array is variable and to obtain a stable voltage from solar panels, DC-DC converters are required for constant power production. There are mainly three converters namely Buck, Boost and Buck-Boost converters which can be used for either increasing or decreasing the voltage. This paper presents mobile charging circuit with a PV source. The circuit structure of the proposed system adopts buck converter combined PWM MPPT technique. In this research, buck converter is used as a charger for charging mobile battery. The input voltage can typically change from (12V initially, down to (5V, and provide a regulated voltage within the range of the 4.5V required for the charging of mobile batteries.

  19. Modelling the impacts of European emission and climate change scenarios on acid-sensitive catchments in Finland

    M. Posch

    2007-09-01

    Full Text Available The dynamic hydro-chemical Model of Acidification of Groundwater in Catchments (MAGIC was used to predict the response of 163 Finnish lake catchments to future acidic deposition and climatic change scenarios. Future deposition was assumed to follow current European emission reduction policies and a scenario based on maximum (technologically feasible reductions (MFR. Future climate (temperature and precipitation was derived from the HadAM3 and ECHAM4/OPYC3 general circulation models under two global scenarios of the Intergovernmental Panel on Climate Change (IPCC: A2 and B2. The combinations resulting in the widest range of future changes were used for simulations, i.e., the A2 scenario results from ECHAM4/OPYC3 (highest predicted change and B2 results from HadAM3 (lowest predicted change. Future scenarios for catchment runoff were obtained from the Finnish watershed simulation and forecasting system. The potential influence of future changes in surface water organic carbon concentrations was also explored using simple empirical relationships based on temperature and sulphate deposition. Surprisingly, current emission reduction policies hardly show any future recovery; however, significant chemical recovery of soil and surface water from acidification was predicted under the MFR emission scenario. The direct influence of climate change (temperate and precipitation on recovery was negligible, as runoff hardly changed; greater precipitation is offset by increased evapotranspiration due to higher temperatures. Predicted changes in dissolved organic carbon induced by reductions in acid deposition or increases in temperature may potentially influence the recovery of surface waters from acidification and may offset the increase in pH resulting from S deposition reductions. However, many climate-induced changes in processes are generally not incorporated in current versions of acidification models. To allow more reliable forecasts, the mechanisms by

  20. Impact of changing DOC concentrations on the potential distribution of acid sensitive biota in a boreal stream network

    H. Laudon

    2008-03-01

    Full Text Available DOC concentrations have increased in many surface waters in Europe and North America over the past few decades. As DOC exudes a strong influence on pH this DOC increase could have detrimental effects on acid sensitive biota in many streams and lakes. To investigate the potential implications of changes in the DOC concentration on stream water biota, we have used a mesoscale boreal stream network in northern Sweden as a case study. The network was sampled for stream water chemistry at 60 locations during both winter base flow and spring flood periods, representing the extremes experienced annually in these streams both in terms of discharge and acidity. The effect of changing DOC on pH was modeled for all sampling locations using an organic acid model, with input DOC concentrations for different scenarios adjusted by between −30% and +50% from measured present concentrations. The resulting effect on pH was then used to quantify the proportion of stream length in the catchment with pH below the acid thresholds of pH 5.5 and pH 5.0. The results suggest that a change in stream water DOC during base flow would have only a limited effect on pH and hence on the stream length with pH below the acid thresholds. During the spring flood on the other hand a change in DOC would strongly influence pH and the stream length with pH below the acid thresholds. For example an increase in DOC concentration of 30% at all sites would increase the proportion of stream length with pH below 5.5 from 37% to 65%, and the proportion of stream length with pH below 5.0 would increase from 18% to 27%. The results suggest that in high DOC waters, even a marginal change in the DOC concentration could impact acid sensitive biota in a large portion of the aquatic landscape.

  1. Impact of changing DOC concentrations on the potential distribution of acid sensitive biota in a boreal stream network

    H. Laudon

    2007-09-01

    Full Text Available DOC concentrations have increased in many surface waters in Europe and North America over the past few decades. As DOC exerts a strong influence on pH this DOC increase could have detrimental effects on acid sensitive biota in many streams and lakes. To investigate the potential implications of changes in the DOC concentration on stream water biota, we have used a mesoscale boreal stream network in northern Sweden as a case study. The network was sampled for stream water chemistry at 60 locations during both winter base flow and spring flood periods, representing the extremes experienced annually in these streams both in terms of discharge and acidity. The effect of changing DOC on pH was modeled for all sampling locations using an organic acid model, with input DOC concentrations for different scenarios adjusted by between –30% and +50% from measured present concentrations. The resulting effect on pH was then used to quantify the proportion of stream length in the catchment with pH below the acid thresholds of pH 5.5 and pH 5.0. The results suggest that a change in stream water DOC during base flow would have only a limited effect on pH and hence on the stream length with pH below the acid thresholds. During the spring flood on the other hand a change in DOC would strongly influence pH and the stream length with pH below the acid thresholds. For example an increase in DOC concentration of 30% at all sites would increase the proportion of stream length with pH below 5.5 from 37% to 65%, and the proportion of stream length with pH below 5.0 would increase from 18% to 27%. The results suggest that in poorly-buffered high DOC waters, even a marginal change in the DOC concentration could impact acid sensitive biota in a large portion of the aquatic landscape.

  2. Step Changes and Deactivation Behavior in the Continuous Decarboxylation of Stearic Acid

    Madsen, Anders Theilgaard; Rozmysłowicz, Bartosz; Simakova, Irina L.; Kilpiö, Teuvo; Leino, Anne-Riikka; Kordás, Krisztián; Eränen, Kari; Mäki-Arvela, Päivi; Murzin, Dmitry Yu.

    2011-01-01

    Deoxygenation of dilute and concentrated stearic acid over 2% Pd/C beads was performed in a continuous reactor at 300 °C and 20 bar pressure of Ar or 5% H2/Ar. Stable operation was obtained in 5% H2 atmosphere, with 95% conversion of 10 mol % dilute stearic acid in dodecane and 12% conversion of pure stearic acid. Deactivation took place in H2-deficient gas atmosphere, probably as a result of the formation of unsaturated products and coking in the pore system. Transient experiments with step ...

  3. The Changes in Color, Soluble Sugars, Organic Acids, Anthocyanins and Aroma Components in "Starkrimson" during the Ripening Period in China.

    Liu, Yulian; Chen, Nianlai; Ma, Zonghuan; Che, Fei; Mao, Juan; Chen, Baihong

    2016-01-01

    "Starkrimson" is a traditional apple cultivar that was developed a long time ago and was widely cultivated in the arid region of the northern Wei River of China. However, little information regarding the quality characteristics of "Starkrimson" fruit has been reported in this area. To elucidate these characteristics, the color, soluble sugars, organic acids, anthocyanins and aroma components were measured during the ripening period through the use of high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The results indicated that the changes in anthocyanin contents took place later than the changes in the Commission International Eclairage (CIE) parameters. Meanwhile, cyanidin 3-galactoside (cy3-gal), fructose, sucrose, glucose and malic acid were the primary organic compounds, and 1-butanol-2-methyl-acetate, 2-hexenal and 1-hexanol were the most abundant aroma components in the skin. Furthermore, rapidly changing soluble sugars and organic acid synchronization took place in the early ripening period, while rapidly changing aroma components occurred later, on the basis of fresh weight. This result suggested that the production of aroma components might be a useful index of apple maturity. PMID:27338331

  4. Inhibitive Performance of a Rust Converter on Corrosion of Mild Steel

    Zhao, X. D.; Cheng, Y. F.; Fan, W.; Vladimir, C.; Volha, V.; Alla, T.

    2014-11-01

    In this work, a rust converter consisting of two steps of processing solutions was prepared to convert iron rust of the steel surface into a protective conversion film. The performance of the converter was evaluated in both neutral and acidic solutions by various electrochemical measurements, including potentiodynamic polarization curves and electrochemical impedance spectroscopy, and surface characterization. The effect of temperature was investigated. It was found that the rust converter is able to effectively convert the iron rust into a conversion film, serving as a barrier layer to block corrosive species from reaching the steel surface.

  5. Study of Changes in a Palm-Shell-Based Activated Carbon Characteristics by Nitric Acid

    W.M.A.W. Daud; A.H. Houshmand

    2010-01-01

    A palm-shell-based activated carbon (PSAC) was oxidized with nitric acid solutions at different conditions. A 2-level full factorial design was considered for experimental conditions. Adsorption of nitrogen at 77 K, and Temperature-Programmed Desorption (TPD) were used to study the oxidized PSAC. Although, oxidation by nitric acid decreases the surface area and pore volume of PSAC, however it creates a considerable amount of different oxygen groups on the surface of PSAC.

  6. Possible protection of Vitamin E and Alpha-lipoic acid against early changes in alloxan diabetic rats

    Sohair A. Moustafa, Nahla S. El-Shenawy and Amro M. Elgheznawy

    2007-12-01

    Full Text Available Diabetes mellitus is a chronic syndrome affecting carbohydrate, fat, protein and nucleic acid metabolism. The current study was undertaken to elucidate the possible role of vitamin E and alpha lipoic acid in combination as an antioxidant and a biological membrane stabilizer in the protection against early complication of diabetes. Administration of alloxan (125 mg/kg wt, i.p. to rats resulted in hyperglycemia, hyperinsulinemia, hypercholesterolemia, hypertriglyceridemia, hyperlipidemia, increase in plasma levels of urea, blood urea nitrogen (BUN, creatinine, uric acid as well as pancreatic thiobarbituric acid reactive substances (TBARS and glutathione (GSH content of both liver and retina. These changes were accompanied with significant decrease in plasma total protein, tumor necrosis factor (TNF, hepatic catalase activity (CAT, and TBARS level of both liver and retina as compared to control group. However, plasma levels of calcium ions (Ca+2 and nitric oxide (NO as well as pancreatic GSH content were not changed. On the other hand, the daily treatment of the diabetic rats with antioxidant mixture attained a reduction in plasma levels of glucose, cholesterol, triglycerides, total lipids, urea, BUN, creatinine, uric acid, TNF, pancreatic TBARS level as well as GSH content of both liver and retina. In contrast, the daily treatment caused an increase in plasma levels of insulin, total proteins, hepatic CAT activity and pancreatic GSH content as compared to diabetic rats. However, plasma levels of Ca+2 and NO as well as TBARS content of both liver and retina were not affected. In conclusion, it is obvious from the present study results that early stage (two weeks of diabetes induce deteriorate changes in carbohydrate, lipid, protein and nucleic acid metabolism accompanied with increasing of oxidative stress in pancreas as compared to both of liver and retina. Moreover, the data of present study indicated the effective role of vitamin E and alpha

  7. The effects of compounding conditions on the properties of fatty acids eutectic mixtures as phase change materials

    Highlights: ► The fully mixing of fatty acids need enough heating time, but too long was waste. ► Heating temperature can affect melting time of solid, not melting point of mixture. ► Ultrasonic hardly improved properties of eutectic mixture, and should be canceled. ► Heating and vibrating operations did not destroy fatty acids’ molecular structure. - Abstract: This work was focused on investigating the effects of compounding conditions on the properties of fatty acids eutectic mixtures as phase change materials (PCMs), and the binary eutectic mixtures of stearic acid (SA) and myristic acid (MA) were selected as representative. The melting points of SA–MA mixtures with varying combination proportions were tested to determine eutectic ratio. Adopting heating-ultrasonic method, the SA–MA mixtures with eutectic ratio were blended under different conditions to obtain a series of eutectic mixtures, and then their thermal properties and chemical structures were analyzed by differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR), respectively. The results showed that the eutectic mass ratio of SA to MA was 36–64%; within certain time range, more heating time can result in lower melting point, but not the longer, the better; when the heating temperature increased, the melting point of eutectic mixture had a little irregular change, but the melting time of solid mixture obviously reduced, so, heating temperature should be considered synthetically to save energy; ultrasonic vibrating process hardly had influences on the properties of eutectic mixtures, and can be canceled; the preparation of fatty acids eutectic mixture did not have any damages to the chemical structures of fatty acids

  8. Effect of ascorbic acid on long-term cold exposure induced changes in thyroid activity in sprague dawley rats

    Objective: To determine the effect of ascorbic acid supplementation on long-term cold exposure induced changes in thyroid activity in Sprague-Dawley rats. Study Design: Experimental study. Place and Duration of Study: Physiology Department of Islamic International Medical College, Rawalpindi, National Institute of Health, Islamabad and Railway Hospital, Rawalpindi, from January to December 2009. Methodology: Ninety Sprague-Dawley rats were randomly divided into three groups of control, cold exposed and cold exposed along with ascorbic acid supplementation. After one month, their thyroid levels were analyzed by using chemiluminescent immunometric Assay on Siemens Immulite 2000 Analyzer. Results: After 4 weeks of cold exposure to experimental animals, the thyroid activity was raised significantly in the cold exposed group as compared to the control group (p-value for T3 difference = 0.004, T4 difference = 0.002 and TSH difference < 0.001). Supplementation with ascorbic acid in the third group normalized the thyroid hormone activity with p-value for difference in levels of T3 being 0.6661, T4 = 0.027 and TSH = 0.0028. Conclusion: Ascorbic acid prevented the cold induced changes in thyroid hormone levels in rodents. (author)

  9. Prey-induced changes in the accumulation of amino acids and phenolic metabolites in the leaves of Drosera capensis L.

    Kováčik, Jozef; Klejdus, Bořivoj; Stork, František; Hedbavny, Josef

    2012-04-01

    Effect of prey feeding (ants Formica fusca) on the quantitative changes in the accumulation of free amino acids, soluble proteins, phenolic metabolites and mineral nutrients in the leaves of carnivorous plant Drosera capensis was studied. Arginine was the most abundant compound in Drosera leaves, while proline was abundant in ants. The amount of the majority of amino acids and their sum were elevated in the fed leaves after 3 and 21 days, and the same, but with further enhancement after 21 days, was observed in ants. Accumulation of amino acids also increased in young non-fed leaves of fed plants. Soluble proteins decreased in ants, but were not enhanced in fed leaves. This confirms the effectiveness of sundew's enzymatic machinery in digestion of prey and suggests that amino acids are not in situ deposited, but rather are allocated within the plant. The content of total soluble phenols, flavonoids and two selected flavonols (quercetin and kaempferol) was not affected by feeding in Drosera leaves, indicating that their high basal level was sufficient for the plant's metabolism and prey-induced changes were mainly N based. The prey also showed to be an important source of other nutrients besides N, and a stimulation of root uptake of some mineral nutrients is assumed (Mg, Cu, Zn). Accumulation of Ca and Na was not affected by feeding. PMID:21140278

  10. 草酸溶液清洗三元催化器的实践研究%Practice Research on Cleaning Three-way Catalytic Converter with Oxalic Acid Solution

    杜慧起

    2016-01-01

    Three-way catalytic converter is one of the most important gas purification device in the automobile exhaust system,it has become a standard equipment which reaches gasoline engine achieveⅢstandards.Due to its expensive cost,low cost maintenance can bring great economic benefits to the owners.%三元催化器是安装在汽车排气系统中最重要的机外净化装置,已经成为汽油机达到国Ⅲ标准的标配。三元催化器的造价比较昂贵,对三元催化器进行低费用修复,能够给车主带来很大的经济效益。

  11. Thermoelectric converter modeling in nuclear space power conversion and regulation

    Thermoelectric converters are being used on low power planetary spacecraft. The same type of conversion was considered for Ground Engineering System development of nuclear power generation under the SP-100 program for high power earth orbiting spacecraft. Here, the baseline design is aimed at generating power using a nuclear reactor to produce heat, a thermoelectric converter to produce electricity, a power regulator to match the output to changing payload demands, and a thermal radiator to dissipate waste heat. The converter performance has to be evaluated considering its characteristics. The characteristics and constraints imposed by the nuclear reactor, the payloads and regulator, and the waste heat radiator should be conformed to. Presented here are a thermodynamic reversible engine model for the thermoelectric converter, and its application to evaluate the converter and system performance under steady-state and transient thermal conditions due to load changes. The type of output voltage regulator, either a series or shunt, has an impact on the converter performance. This impact is evaluated and advantages and disadvantages of both are indicated. The converter performance is evaluated along its voltage-current characteristics. Influence of the conversion efficiency is assessed on thermal distribution and electrical output

  12. Study and application on lean resin converting in uranium mill

    The field test about sulphuric acid used to convert lean resin was finished. The results indicated sulphuric acid could replace chlorin in lean resin and could be reclaimed to desorption procedure. The consumption of NaCl decreased, the chlorin concentration of tailing decreased too. Both of uranium loss and waste water volume were reduced. The uranium concentration of tailing decreased and energy saving and emission reduction can be achieved. (authors)

  13. Changes of sour taste and the composition of carboxylic acids induced in brewed coffee by γ-irradiation on green beans and storage of roast beans

    Brazil santos green coffee beans were irradiated with 60Co-γ rays at doses of 0, 0.05, 0.5 and 1.5 Mrad respectively and changes of the composition of carboxylic acids in roast beans were analyzed by means of GLC together with those of the organoleptic properties of roast beans during storage by use of the cup testing. The total acid content immediately after roasting was about 6,000 mg/100 g (roast beans) and the composition of carboxylic acids was as follows. Chlorogenic acid: hydroxy-carboxylic acids: mono-carboxylic acid: others = 73 : 18 : 7 : 2. Fresh coffee flavour was influenced markedly especially in acid taste by both irradiation of γ-rays on green beans and storage of roast beans, because of the change of above acids composition. On γ-ray irradiation, the change of the acid composition were more clear than that of stored roast beans. Therefore, the quality of γ-irradiated coffee beans seems to be closely associated with the ratio of hydroxy-carboxylic acids mg/ monocarboxylic acids mg, but little with total acid content. (author)

  14. Primary Parallel Isolated Boost Converter with Bidirectional Operation

    Hernandez Botella, Juan Carlos; Mira Albert, Maria del Carmen; Sen, Gökhan; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    This paper presents a bidirectional dc/dc converter operated with batteries both in the input and output. Primary parallel isolated boost converter (PPIBC) with transformer series connection on the high voltage side is preferred due to its ability to handle high currents in the low voltage side....... The converter has been modeled using non-ideal components and operated without any additional circuitry for startup using a digital soft-start procedure. Simulated and measured loop gains have been compared for the validity of the model. On-the-fly current direction change has been achieved between...

  15. Conducted EMI Evaluation and Reduction in a Forward Switching Converter

    Mohammad Rouhollah Yazdani

    2012-04-01

    Full Text Available In switching power converters, electromagnetic interference (EMI is produced due to the fast changes of the voltage and current. Among switching topologies used in low and medium powers, forward converter is vastly employed which needs resetting transformer core. In this paper, a forward converter with reset winding is modeled to predict conducted EMI. To evaluate the EMI model, EMI measurement results are presented. To select an optimum reset scheme from EMI viewpoint, three reset techniques are compared using experimental results. After selecting the proper reset scheme, two EMI mitigation methods are proposed and the practical EMI reduction is presented.

  16. Benefits of omega-3 fatty acid against bone changes in salt-loaded rats: possible role of kidney

    Ahmed, Mona A.; Abd EL Samad, Abeer A

    2013-01-01

    There is evidence that dietary fats are important components contributing in bone health and that bone mineral density is inversely related to sodium intake. Salt loading is also known to impose negative effects on renal function. The present study aimed to determine the effect of the polyunsaturated fatty acid omega-3 on bone changes imposed by salt loading, highlighting the role of kidney as a potential mechanism involved in this effect. Male Wistar rats were divided into three groups: cont...

  17. Study of possible changes brought about by plutonium oxide in the acid phosphatase activity of alveolar macrophages of the rabbit

    This report describes the various techniques used for determining the acid phosphatase activity of alveolar rabbit macrophages after inhalation of radioactive plutonium oxide particles, exposure of the animals, removal and sampling of the alveolar cells, and technical dosage. The results obtained are presented; they do not make it possible, in this particular case, to affirm that an important change in the enzymatic activity studied occurs. (author)

  18. Modelling the impacts of European emission and climate change scenarios on acid-sensitive catchments in Finland

    Posch, M.; Aherne, J.; Forsius, M.; Fronzek, S.; N. Veijalainen

    2008-01-01

    The dynamic hydro-chemical Model of Acidification of Groundwater in Catchments (MAGIC) was used to predict the response of 163 Finnish lake catchments to future acidic deposition and climatic change scenarios. Future deposition was assumed to follow current European emission reduction policies and a scenario based on maximum (technologically) feasible reductions (MFR). Future climate (temperature and precipitation) was derived from the HadAM3 and ECHAM4/OPYC3 general circula...

  19. Modelling the impacts of European emission and climate change scenarios on acid-sensitive catchments in Finland

    Posch, M.; Aherne, J.; Forsius, M.; Fronzek, S.; N. Veijalainen

    2008-01-01

    The dynamic hydro-chemical Model of Acidification of Groundwater in Catchments (MAGIC) was used to predict the response of 163 Finnish lake catchments to future acidic deposition and climatic change scenarios. Future deposition was assumed to follow current European emission reduction policies and a scenario based on maximum (technologically) feasible reductions (MFR). Future climate (temperature and precipitation) was derived from the HadAM3 and ECHAM4/OPYC3 general circulation models under ...

  20. [Deoxyribonucleoprotein and nucleic acid changes in the tissues of rats after a flight on the Kosmos-1129 biosatellite].

    Misŭrova, E U; TIgranian, R A; Sabova, T; Prasliĭcka, M

    1982-01-01

    The concentration of polydeoxyribonucleotides and nucleic acids was measured in the spleen, thymus, liver, bone marrow and blood of rats flown for 18.5 days on Cosmos-1129. The exposure led to an increase in the polydeoxyribonucleotide content in the thymus and a decrease of the DNA and RNA concentration in the spleen and thymus. These changes returned to normal at R+6. PMID:6181292

  1. Selection of dairy culture and changes of Podravec cheese acidity during production

    Slavko Kirin

    2002-06-01

    Full Text Available The selection and characteristics of dairy culture play a basic role in all types of cheese production process. The most important characteristic is acidification ability i.e. lactic acid formation, which regulates manufacturing and maturing conditions of cheese, thus affecting its organoleptic characteristics as well. In this work the results on control of acidity increase in Podravec cheeseproduction are presented. In the production process, a technical culture as well as identical frozen and concentrated culture, with and without auxiliary Streptococcus thermophilus for direct milk inoculation, were used. It was established that the acidity, expressed as pH value, is more intensively developed in cheeses produced with culture for direct inoculation. This was especially evident in the first phases of production i.e. before cheese salting. During salting the acidity of cheeses, in both cases, was almoust identical. Cheeses produced with identical frozen culture and auxiliary Streptococcus thermophilus culture had more pronounced acidity before salting and lower after salting in comparison with cheeses with the mentioned two cultures. Organoleptic and other characteristics of mature cheeses were identical.

  2. Post combustion in converter steelmaking

    Oghbasilasie, H.; Holappa, L.

    1997-12-31

    The purpose of this work is to study the fundamentals of post combustion and the effect of different process parameters on the post combustion ratio (PCR) and heat transfer efficiency (HTE) in converter steelmaking process. The PCR and HTE have been determined under normal operating conditions. Trials assessed the effect of lance height, vessel volume, foaming slag and pellet additions on PCR and HTE. Based on enthalpy considerations, post combustion of CO gas is regarded as one of the most effective means of increasing the heat supply to the BOP. The thermodynamic study of gas-metal-slag reactions gives the limiting conditions for post combustion inside the converter reactor. Different process parameters influencing both thermodynamic equilibria and kinetic conditions can greatly affect the post combustion ratio. Different features of converter processes as well smelting reduction processes utilizing post combustion have been reviewed. (orig.) SULA 2 Research Programme; 26 refs.

  3. Changes in Plasma Phospholipid Fatty Acid Patterns and their Impact on Plasma Triglyceride Levels Following Fish Oil Supplementation

    Cormier H; Rudkowska I; Lemieux S; Couture P; Julien P; Vohl MC

    2015-01-01

    The objective of the present study was to test for associations between changes in fatty acids (FAs) and changes in plasma triglyceride (TG) levels after an n-3 FA supplementation and to test whether SNPs from the FADS gene cluster were associated with plasma FA levels or with specific FA patterns. A total of 210 subjects completed a 2-wk run-in period followed by 6-wk supplementation with 5g/d of fish oil. FA profiles of plasma phospholipids (PPLs) were obtained and 19 SNPs fr...

  4. Proliferation-dependent changes in amino acid transport and glucose metabolism in glioma cell lines

    Amino acid imaging is increasingly being used for assessment of brain tumor malignancy, extent of disease, and prognosis. This study explores the relationship between proliferative activity, amino acid transport, and glucose metabolism in three glioma cell lines (U87, Hs683, C6) at different phases of growth in culture. Growth phase was characterized by direct cell counting, proliferation index determined by flow cytometry, and [3H]thymidine (TdR) accumulation, and was compared with the uptake of two non-metabolized amino acids ([14C]aminocyclopentane carboxylic acid (ACPC) and [14C]aminoisobutyric acid (AIB)), and [18F]fluorodeoxyglucose (FDG). Highly significant relationships between cell number (density), proliferation index, and TdR accumulation rate were observed in all cell lines (r>0.99). Influx (K1) of both ACPC and AIB was directly related to cell density, and inversely related to the proliferation index and TdR accumulation in all cell lines. The volume of distribution (Vd) for ACPC and AIB was lowest during rapid growth and highest during the near-plateau growth phase in all cell lines. FDG accumulation in Hs683 and C6 cells was unaffected by proliferation rate, growth phase, and cell density, whereas FDG accumulation was correlated with TdR accumulation, growth phase, and cell density in U87 cells. This study demonstrates that proliferation rate and glucose metabolism are not necessarily co-related in all glioma cell lines. The values of K1 and Vd for ACPC and AIB under different growth conditions suggest that these tumor cell lines can up-regulate amino acid transporters in their cell membranes when their growth conditions become adverse and less than optimal. (orig.)

  5. Power electronic converters PWM strategies and current control techniques

    Monmasson, Eric

    2013-01-01

    A voltage converter changes the voltage of an electrical power source and is usually combined with other components to create a power supply. This title is devoted to the control of static converters, which deals with pulse-width modulation (PWM) techniques, and also discusses methods for current control. Various application cases are treated. The book is ideal for professionals in power engineering, power electronics, and electric drives industries, as well as practicing engineers, university professors, postdoctoral fellows, and graduate students.

  6. Basic Aspects Related to Operation of Engine Catalytic Converters

    Stefan POSTRZEDNIK; Zmudka, Zbigniew; Ciesiolkiewicz, Adam

    2004-01-01

    Experimental research on the diesel engine 6C107 equipped with selected oxidation catalytic converters was carried out. Specific emissions of toxic substances were investigated in the whole operation range of the engine before and after catalysts. Thus, changes of the emission indices within the catalysts and conversion efficiencies of the harmful substances were evaluated. Besides, temperature threshold of the catalytic action was determined too. Apart from chemical efficiency of the convert...

  7. Digital Control of Converters for Distributed Power Generations

    Skjellnes, Tore

    2008-01-01

    Pulse width modulated converters are becoming increasingly popular as their cost decreases and power rating increases. The new trend of smallscale power producers, often using renewable energy sources, has created new demands for delivery of energy to the grid.A major advantage of the pulse width modulated converter is the ability to control the output voltage at any point in the voltage period. This enables rapid response to load changes and non-linear loads. In addition it can shape the vol...

  8. Changes in fatty acid and sterol composition during oogenesis in the pearl oyster Pinctada margaritifera

    Vahirua Lechat, I; Laure, F; Le Coz, Jean-rene; Bianchini, J; Bellais, M; Le Moullac, Gilles

    2008-01-01

    The fatty acid and sterol composition of the oyster Pinctada margaritifera during oogenesis and in eggs was analysed. No major differences were observed during oogenesis, but the egg composition was significantly different from that of gonads. The amount of saturated fatty acids was the highest in eggs and the C16:0 predominant (P < 5%); by contrast, the amount of 22:6(n-3) was significantly lower (P < 5%) than in gonads. No major differences were observed for the polar lipid (PL) composition...

  9. Role and significance of polyunsaturated fatty acids in nutrition in prevention and treatment of atherosclerosis

    Ristić Vanja I.

    2003-01-01

    Full Text Available Introduction Hyperlipoproteinemia is a key factor in development of atherosclerosis, whereas regression of atherosclerosis mostly depends on decreasing the plasma level of total and LDL-cholesterol. Many studies have reported the hypocholesterolemic effect of linolenic acid. Types of polyunsaturated fatty acids (PUFA Linoleic and α-linolenic acids are essential fatty acids. The main sources of linoleic acid are vegetable seeds and of α-linolenic acid - green parts of plants. α-linolenic acid is converted to eicosapentaenoic and docosahexaenoic acid. Linoleic acid is converted into arachidonic acid competing with eicosapentaenoic acid in the starting point for synthesis of eicosanoids, which are strong regulators of cell functions and as such, very important in physiology and pathophysiology of cardiovascular system. Eicosanoids derived from eicosapentaenoic acid have different biological properties in regard to those derived from arachidonic acid, i.e. their global effects result in decreased vasoconstriction platelet aggregation and leukocyte toxicity. Role and significant of PUFA The n-6 to n-3 ratio of polyunsaturated fatty acids in the food is very important, and an optimal ratio 4 to 1 in diet is a major issue. Traditional western diets present absolute or relative deficiency of n-3 polyunsaturated fatty acids, and a ratio 15-20 to 1. In our diet fish and fish oil are sources of eicosapentaenoic and docosahexaenoic acid. Refined and processed vegetable oils change the nature of polyunsaturated fatty acids and obtained derivates have atherogenic properties.

  10. Changes in plasma and erythrocyte omega-6 and omega-3 fatty acids in response to intravenous supply of omega-3 fatty acids in patients with hepatic colorectal metastases

    Al-Taan, Omer; Stephenson, James A; Spencer, Laura; Pollard, Cristina; West, Annette L.; Calder, Philip C.; Metcalfe, Matthew; Dennison, Ashley R

    2013-01-01

    Background Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are functionally the most important omega-3 polyunsaturated fatty acids (PUFAs). Oral supply of these fatty acids increases their levels in plasma and cell membranes, often at the expense of the omega-6 PUFAs arachidonic acid (ARA) and linoleic acid. This results in an altered pattern of lipid mediator production to one which is less pro-inflammatory. We investigated whether short term intravenous supply of omega-3 PUFAs co...

  11. Studies concerning the anion ex-change resins catalyzed esterification of epichlorohydrin with organic acids

    E.I. Muresan

    2009-09-01

    Full Text Available The paper studies the esterification of carboxylic acids with epichlorohydrin over two macroporous strong base anion exchange resins with different polymer matrix. For both resins, the influence of reaction parameters (temperature, catalyst loading, molar ratio on the reaction rate and the yields of the two isomeric esters were investigated.

  12. Changes in soil chemistry following wood and grass biochar amendments to an acidic agricultural production soil

    The utility of biochars produced by biomass gasification for remediation of acidic production soils and plant growth in general is not as well known compared to effects from biochars resulting from pyrolysis. Recent characterization of biochar produced from gasification of Kentucky bluegrass (Poa pr...

  13. GROWTH CHANGES OF APPLE SEEDLINGS IN RESPONSE TO SIMULATED ACID RAIN

    In a greenhouse experiment, Malus hupehensis seedlings were treated weekly with simulated acid rain solutions ranging from pH 2.25 to pH 7.0. Necrotic lesions developed on leaves at pH 2.25 and pH 2.50 immediately after the first application at the 8-node stage. Following the 9th...

  14. Changes in actin dynamics are involved in salicylic acid signaling pathway

    Matoušková, J.; Janda, M.; Fišer, R.; Šašek, Vladimír; Kocourková, Daniela; Burketová, Lenka; Dušková, J.; Martinec, Jan; Valentová, O.

    2014-01-01

    Roč. 223, JUN 2014 (2014), s. 36-44. ISSN 0168-9452 R&D Projects: GA ČR(CZ) GAP501/11/1654 Institutional support: RVO:61389030 Keywords : Actin dynamics * Salicylic acid * PR genes Subject RIV: CE - Biochemistry Impact factor: 3.607, year: 2014

  15. Changes in metabolism and concentration of amino acids during yeast colony development

    Váchová, Libuše; Begany, Markéta; Kučerová, Helena; Palková, Z.

    Dubrovnik : Verlag, 2006, s. 91-91. [EMBO/HHMI Central European Scientists Meeting. Dubrovnik (HR), 15.06.2006-17.06.2006] R&D Projects: GA ČR GA204/05/0294; GA MŠk(CZ) LC531 Institutional research plan: CEZ:AV0Z50200510 Keywords : amino acids * yeast colonies Subject RIV: EE - Microbiology, Virology

  16. Changes in Trans Fat and Fatty Acids in Fast Food Menu Items

    Recent interest in trans fatty acid intake and subsequent recommendations included in the 2005 Dietary Guidelines for Americans to decrease intake has led to extensive product reformulations of widely consumed foods high in trans fat. As part of these efforts to provide current and accurate nutrien...

  17. Metabolite changes during natural and lactic acid bacteria fermentations in pastes of soybeans and soybean-maize blends.

    Ng'ong'ola-Manani, Tinna Austen; Ostlie, Hilde Marit; Mwangwela, Agnes Mbachi; Wicklund, Trude

    2014-11-01

    The effect of natural and lactic acid bacteria (LAB) fermentation processes on metabolite changes in pastes of soybeans and soybean-maize blends was studied. Pastes composed of 100% soybeans, 90% soybeans and 10% maize, and 75% soybeans and 25% maize were naturally fermented (NFP), and were fermented by lactic acid bacteria (LFP). LAB fermentation processes were facilitated through back-slopping using a traditional fermented gruel, thobwa as an inoculum. Naturally fermented pastes were designated 100S, 90S, and 75S, while LFP were designated 100SBS, 90SBS, and 75SBS. All samples, except 75SBS, showed highest increase in soluble protein content at 48 h and this was highest in 100S (49%) followed by 90SBS (15%), while increases in 100SBS, 90S, and 75S were about 12%. Significant (P Lactic acid was 2.5- to 3.5-fold higher in LFP than in NFP, and other organic acids detected were acetate and succinate. Maltose levels were the highest among the reducing sugars and were two to four times higher in LFP than in NFP at the beginning of the fermentation, but at 72 h, only fructose levels were significantly (P Enzyme activities were higher in LFP at 0 h, but at 72 h, the enzyme activities were higher in NFP. Both fermentation processes improved nutritional quality through increased protein and amino acid solubility and degradation of phytic acid (85% in NFP and 49% in LFP by 72 h). PMID:25493196

  18. Research on the Changes to the Lipid/Polymer Membrane Used in the Acidic Bitterness Sensor Caused by Preconditioning

    Yuhei Harada

    2016-02-01

    Full Text Available A taste sensor that uses lipid/polymer membranes can evaluate aftertastes felt by humans using Change in membrane Potential caused by Adsorption (CPA measurements. The sensor membrane for evaluating bitterness, which is caused by acidic bitter substances such as iso-alpha acid contained in beer, needs an immersion process in monosodium glutamate (MSG solution, called “MSG preconditioning”. However, what happens to the lipid/polymer membrane during MSG preconditioning is not clear. Therefore, we carried out three experiments to investigate the changes in the lipid/polymer membrane caused by the MSG preconditioning, i.e., measurements of the taste sensor, measurements of the amount of the bitterness substance adsorbed onto the membrane and measurements of the contact angle of the membrane surface. The CPA values increased as the preconditioning process progressed, and became stable after 3 d of preconditioning. The response potentials to the reference solution showed the same tendency of the CPA value change during the preconditioning period. The contact angle of the lipid/polymer membrane surface decreased after 7 d of MSG preconditioning; in short, the surface of the lipid/polymer membrane became hydrophilic during MSG preconditioning. The amount of adsorbed iso-alpha acid was increased until 5 d preconditioning, and then it decreased. In this study, we revealed that the CPA values increased with the progress of MSG preconditioning in spite of the decrease of the amount of iso-alpha acid adsorbed onto the lipid/polymer membrane, and it was indicated that the CPA values increase because the sensor sensitivity was improved by the MSG preconditioning.

  19. Charge-pump voltage converter

    Brainard, John P.; Christenson, Todd R.

    2009-11-03

    A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

  20. Complete amino acid sequence of the human alpha 5 (IV) collagen chain and identification of a single-base mutation in exon 23 converting glycine 521 in the collagenous domain to cysteine in an Alport syndrome patient

    Zhou, J; Hertz, Jens Michael; Leinonen, A; Tryggvason, K

    1992-01-01

    alleles. The mutation which was located to exon 23 was sequenced from a polymerase chain reaction-amplified product, and shown to be a G----T change in the coding strand. The mutation changed the GGT codon of glycine 521 to cysteine. The same mutation was found in one allele of the female cousin. The...

  1. Response of Halomonas campisalis to saline stress: changes in growth kinetics, compatible solute production and membrane phospholipid fatty acid composition.

    Aston, John E; Peyton, Brent M

    2007-09-01

    The haloalkaliphile Halomonas campisalis, isolated near Soap Lake, Washington, was grown under both aerobic and denitrifying conditions from 0 to 260 g L(-1) NaCl, with optimal growth occurring at 20 and 30 g L(-1) NaCl, respectively. Halomonas campisalis was observed to produce high concentrations of compatible solutes, most notably ectoine (up to 500 mM within the cytoplasm), but hydroxyectoine and glycine betaine were also detected. The types and amounts of compatible solutes produced depended on salinity and specific growth rate, as well as on the terminal electron acceptor available (O(2) or NO(3) (-)). A decrease in ectoine production was observed with NO(3) (-) as compared with O(2) as the terminal electron acceptor. In addition, changes in the phospholipid fatty acid composition were measured with changing salinity. An increase in trans fatty acids was observed in the absence of salinity, and may be a response to membrane instability. Cyclic fatty acids were also observed to increase, both in the absence of salinity, and at very high salinities, indicating cell stress at these conditions. PMID:17651393

  2. Assessment of the chemical changes induced in human melanoma cells by boric acid treatment using infrared imaging

    Acerbo, A.; Miller, L.

    2009-07-01

    Boron is found in everyday foods and drinking water in trace quantities. Boron exists as boric acid (BA) within plants and animals, where low levels have been linked to cancer incidence. However, this correlation is not well characterized. In this study, we examined the chemical and morphological effects of BA on human skin melanoma cells (SK-MEL28) using Fourier Transform InfraRed Imaging (FTIRI) with a Focal Plane Array (FPA) detector. Cells were grown under concentrations of BA ranging from 0 to 50 mM. Cell viability was determined after 1, 2, 3, 5, 7 and 10 days using trypan blue staining. With FTIRI, images of approximately twenty cells per time point per condition were collected. Principal components analysis (PCA) was used to evaluate changes in cell composition, with particular focus on the lipid, protein, and nucleic acid spectral components. Results from trypan blue staining revealed decreased cell viability as BA concentration increased. FTIRI data indicated that the protein and lipid contents (as indicated by the lipid/protein ratio) did not undergo substantial changes due to BA treatment. In contrast, the nucleic acid/protein ratio significantly decreased with BA treatment. PCA results showed an increase in {beta}-sheet protein at higher concentrations of BA (12.5, 25, and 50 mM). Together, these results suggest that high concentrations of BA have an anti-proliferative effect and show signs consistent with apoptosis.

  3. Fabrication and characterization of stearic acid/polyaniline composite with electrical conductivity as phase change materials for thermal energy storage

    Highlights: • Stearic acid/polyaniline composite PCM with electrical conductivity was fabricated. • Stearic acid acted as thermal energy storage media and doping acid. • Latent heats of SA/PANI are as high as the same type composites. • Improved electrical conductivity of capsules is 0.7042 S cm−1. - Abstract: This paper presents the experimental investigation on the thermal properties and electrical conductivity of the new microencapsulated phase change material by entrapping of stearic acid (SA) into PANI (polyaniline) shell through self-assembly method. Experimental results reveal that PANI nuclei grew on the surface of SA, and then copied its original morphological structure and finally exhibited peony flower-like morphology. The two components have good compatibility and have no chemical reaction both in the process of fabrication and subsequent use, while hydrogen bondings between the imino groups and carboxyl groups exist. The maximum mass fraction of stearic acid loaded in SA/PANI is determined as high as 62.1 wt% without seepage of melted SA from capsules. Due to the secondary doping with carboxyl group, the composite phase change material embedded with SA exhibits improved electrical conductivity from 0.3968 S cm−1 to 0.7042 S cm−1 when compared to PANI. The phase change temperatures and latent heats of SA/PANI are measured to be 55.6 °C and 113.02 J/g for melting and, 50.8 °C and 112.58 J/g for freezing, respectively. TG analysis test revealed that the prepared SA/PANI composite PCM has high thermal durability in working temperature range. Moreover, the results of DSC, FT-IR, TG, conductivity investigation and thermal cycling test are all show that the thermal reliability and electrical conductivity of the SA/APNI have imperceptible changes. In total, the additional electrical conductivity, high heat storage potential and good thermal reliability and stability facilitated SA/PANI to be considered as a viable candidate for thermal energy

  4. Proteomic analysis of changes in the protein composition of MCF-7 human breast cancer cells induced by all-trans retinoic acid, 9-cis retinoic acid, and their combination

    Flodrová, D. (Dana); Benkovská, D. (Dagmar); Macejová, D.; Bialesova, L.; Hunakova, L.; Brtko, J.; Bobálová, J. (Janette)

    2015-01-01

    Retinoic acid (all-trans and 9-cis) isomers represent important therapeutic agents for many types of cancers, including human breast cancer. Changes in protein composition of the MCF-7 human breast cancer cells were induced by all-trans retinoic acid, 9-cis retinoic acid, and their combination and subsequently proteomic strategies based on bottom-up method were applied. Proposed approach was used for the analysis of proteins extracted from MCF-7 human breast cancer cell line utilizing a ...

  5. Temporal changes (1997–2012) of perfluoroalkyl acids and selected precursors (including isomers) in Swedish human serum

    Concentrations (including isomer patterns) and temporal changes (1997–2012) of perfluoroalkyl acids (PFAAs) and selected perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylic acid (PFCA) precursors were determined in serum samples from Swedish women. Perfluorooctane sulfonamide (FOSA) and perfluorooctane sulfonamidoacetic acid (FOSAA), as well as its N-methyl and N-ethyl derivatives (MeFOSAA and EtFOSAA) were consistently detected. Highest PFOS precursor concentrations were found for EtFOSAA (before year 2000) or MeFOSAA and FOSAA (after 2000). Disappearance half-lives for all PFOS precursors were shorter compared to PFOS. 4:2/6:2 and 6:2/6:2 polyfluoroalkyl phosphate diesters (diPAPs) were detected in <60% of the samples, whereas 6:2/8:2 and 8:2/8:2 diPAPs were detected in >60% of the samples, but showed no significant change in concentrations over time. Linear and sum-branched isomers were quantified separately for three PFAAs and three precursors. Significant changes between 1997 and 2012 in the % linear isomer were observed for PFOA and FOSA (increase) and PFOS (decrease). - Highlights: • Four PFOS precursors and four diPAPs were detected in Swedish human serum. • Disappearance half-lives (1997–2012) of PFOS precursors were shorter compared to PFOS. • No significant temporal trends were found for diPAPs in human serum. • Linear and branched isomers were detected for three PFAAs and three precursors. - The disappearance half-lives (1997–2012) of four PFOS precursors in human serum were shorter compared to PFOS, whereas for four detected diPAPs no concentration change over time was observed

  6. Lipid changes associated with differentiation and apoptotic response of colonic cells exposed to dietary fatty acids

    Hofmanová, Jiřina; Koubková, Zuzana; Stixová, Lenka; Kočí, Lenka; Kozubík, Alois

    Budapest, 2008. s. 105. [ISAC XXIV International Congress, Cytometry in the Age of Systems Biology. 17.05.2008-21.05.2008, Budapest] R&D Projects: GA AV ČR(CZ) 1QS500040507; GA ČR(CZ) GA524/07/1178; GA ČR(CZ) GA301/07/1557 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : fatty acids * cytokinetics * colon cancer Subject RIV: BO - Biophysics

  7. The effect of convalescent meridian acupressure after exercise on stress hormones and lactic acid concentration changes

    Shin, Won

    2013-01-01

    Meridian acupressure has been used as the one way recovering body conditions. The purpose of this study was to investigate whether meridian acupressure is effective on removing cortisol, norepinephrine, epinephrine, and lactic acid in blood following exercise. The subjects were 12 healthy male college students and data were processed using SPSS 12.0 statistical program and the results were calculated by setting the significance level at P< 0.05. First, there was a significant difference betwe...

  8. Assessment of morphological changes and DNA quantification: An in vitro study on acid-immersed teeth

    Sowmya, K.; U S Sudheendra; Samar Khan; Neelu Nagpal; S J Prathamesh

    2013-01-01

    Context: Acid immersion of victim's body is one of the methods employed to subvert identification of the victim, and hence of the perpetrator. Being hardest and chemically the most stable tissue in the body, teeth can be an important forensic investigative medium in both living and nonliving populations. Teeth are also good reservoirs of both cellular and mitochondrial DNA; however, the quality and quantity of DNA obtained varies according to the environment the tooth has been subjected to. D...

  9. Urinary liver-type fatty acid-binding protein change in gestational diabetes mellitus.

    Fu, Wen-Jin; Wang, Du-Juan; Deng, Ren-Tang; Huang, Zhi-Hong; Chen, Mei-Lian; Jang, You-Ming; Wen, Shu; Yang, Hong-Ling; Huang, Xian-zhang

    2015-09-01

    We compared urinary liver-type fatty acid-binding protein (L-FABP) among non-pregnant and pregnant women with and without gestational diabetes mellitus (GDM). Higher urinary L-FABP was found in pregnant with and without GDM, and considerably higher urinary L-FABP was found in the GDM group compared with the non-GDM group. Hyperglycemia and anemia were related with high urinary L-FABP expression. PMID:26254248

  10. Quantitative analysis of changes in the phosphoproteome of maize induced by the plant hormone salicylic acid

    Wu, Liuji; Hu, Xiuli; Wang, Shunxi; Tian, Lei; Pang, Yanjie; Han, Zanping; Wu, Liancheng; Chen, Yanhui

    2015-01-01

    Phytohormone salicylic acid (SA) plays an important role in regulating various physiological and biochemical processes. Our previous study identified several protein kinases responsive to SA, suggesting that phosphorylation events play an important role in the plant response to SA. In this study, we characterized the phosphoproteome of maize in response to SA using isotope tags for relative and absolute quantification (iTRAQ) technology and TiO2 enrichment method. Based on LC-MS/MS analysis, ...

  11. Parametric study of laser photovoltaic energy converters

    Walker, G. H.; Heinbockel, J. H.

    1987-01-01

    Photovoltaic converters are of interest for converting laser power to electrical power in a space-based laser power system. This paper describes a model for photovoltaic laser converters and the application of this model to a neodymium laser silicon photovoltaic converter system. A parametric study which defines the sensitivity of the photovoltaic parameters is described. An optimized silicon photovoltaic converter has an efficiency greater than 50 percent for 1000 W/sq cm of neodymium laser radiation.

  12. Current control method of thyristor converter for PF superconducting coil in KSTAR

    Choi, Jae-hoon, E-mail: jaehoon@nfri.re.kr [National Fusion Research Institute (NFRI), 169-148 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Ahn, Hyun-sik [POSCO ICT, 622, Sampyeong-dong, Bundang-gu, Seongnam-si, Kyeonggi-do 463-400 (Korea, Republic of); Lee, Dong-keun; Jin, Jong-kuk [National Fusion Research Institute (NFRI), 169-148 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Jang, Gye-yong; Seong, Dae-kyung; Yun, Min-sung; Shin, Hyun-seok [POSCO ICT, 622, Sampyeong-dong, Bundang-gu, Seongnam-si, Kyeonggi-do 463-400 (Korea, Republic of); Kim, Yaung-soo [National Fusion Research Institute (NFRI), 169-148 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of)

    2012-11-15

    This paper presents the current control method of thyristor converter which is applied to PF power supply in KSTAR. The thyristor converter for PF superconducting coil is composed of two 6 pulse converters and each converter is connected in parallel using DC reactor to reduce voltage ripple, current rating of converter and harmonic components. For 4 quadrant operation, each 6 pulse converter has six arms of anti-paralleled thyristor device, back-to-back connection. To apply this converter on KSTAR PF coil, stable coil current control is needed. Additionally, PF coil needs smooth current control without dead-time when current polarity changes and it is not easy in back-to-back thyristor converter. For this reason, zero crossing current control using circulating current and test results are introduced in this paper and it was satisfactory.

  13. Study on the change of total fat content and fatty acid composition of the ethanol extract from cooking drips of thunnus thynnus by ionizing irradiation

    Lee, Hee Sub; Choi, Jong Il; Kim, Hyun Joo; Kim, Jin Kyu; Byun, Myung Woo; Lee, Ju Woon [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Yoo, Cheon Woo; Kim, Ju Bong [Dongwon Research and Development Center, Seongnam (Korea, Republic of); Hwang, Young Jung [Division of Food Science, Jinju International University, Jinju (Korea, Republic of); Chung, Young Jin [Dept. of Food and Nutrition, Chungnam National University, Daejeon (Korea, Republic of)

    2008-05-15

    This study was conducted to examine the effect of a gamma irradiation (GM) and an electron-beam irradiation (EB) on the total fat content and fatty acid composition of ethanol extract from cooking drips of Thunnus thynnus (ECT). The total fat content of samples were determined by fat extraction (Folch method) and fatty acid composition was by gas chromatography mass spectrometry (GC-MS) after fat extraction. The results showed that total fat contents were not changed by GM and EB up to the dose of 50 kGy. The content of unsaturated fatty acids (USFA) such as vaccenic acid and DHA, was decreased by irradiation. But, the content of palmitoleic acid was not changed by GM. In contrast, the content of saturated fatty acids(SFA) such as myristic acid and palmitic acid, was increased by the irradiation. But, the content of stearic acid was decreased with the increase of irradiation dose. Also, it has been shown that the GM had further affected the change of fatty acid content than EB.

  14. Modelling the impacts of European emission and climate change scenarios on acid-sensitive catchments in Finland

    M. Posch

    2008-03-01

    Full Text Available The dynamic hydro-chemical Model of Acidification of Groundwater in Catchments (MAGIC was used to predict the response of 163 Finnish lake catchments to future acidic deposition and climatic change scenarios. Future deposition was assumed to follow current European emission reduction policies and a scenario based on maximum (technologically feasible reductions (MFR. Future climate (temperature and precipitation was derived from the HadAM3 and ECHAM4/OPYC3 general circulation models under two global scenarios of the Intergovernmental Panel on Climate Change (IPCC: A2 and B2. The combinations resulting in the widest range of future changes were used for simulations, i.e., the A2 scenario results from ECHAM4/OPYC3 (highest predicted change and B2 results from HadAM3 (lowest predicted change. Future scenarios for catchment runoff were obtained from the Finnish watershed simulation and forecasting system. The potential influence of future changes in surface water organic carbon concentrations was also explored using simple empirical relationships based on temperature and sulphate deposition. Surprisingly, current emission reduction policies hardly show any future recovery; however, significant chemical recovery of soil and surface water from acidification was predicted under the MFR emission scenario. The direct influence of climate change (temperate and precipitation on recovery was negligible, as runoff hardly changed; greater precipitation is offset by increased evapotranspiration due to higher temperatures. However, two exploratory empirical DOC models indicated that changes in sulphur deposition or temperature could have a confounding influence on the recovery of surface waters from acidification, and that the corresponding increases in DOC concentrations may offset the recovery in pH due to reductions in acidifying depositions.

  15. Understanding nucleic acid structural changes by comparing wide-angle x-ray scattering (WAXS) experiments to molecular dynamics simulations

    Pabit, Suzette A.; Katz, Andrea M.; Tolokh, Igor S.; Drozdetski, Aleksander; Baker, Nathan; Onufriev, Alexey V.; Pollack, Lois

    2016-05-01

    Wide-angle x-ray scattering (WAXS) is emerging as a powerful tool for increasing the resolution of solution structure measurements of biomolecules. Compared to its better known complement, small angle x-ray scattering (SAXS), WAXS targets higher scattering angles and can enhance structural studies of molecules by accessing finer details of solution structures. Although the extension from SAXS to WAXS is easy to implement experimentally, the computational tools required to fully harness the power of WAXS are still under development. Currently, WAXS is employed to study structural changes and ligand binding in proteins; however, the methods are not as fully developed for nucleic acids. Here, we show how WAXS can qualitatively characterize nucleic acid structures as well as the small but significant structural changes driven by the addition of multivalent ions. We show the potential of WAXS to test all-atom molecular dynamics (MD) simulations and to provide insight into understanding how the trivalent ion cobalt(III) hexammine (CoHex) affects the structure of RNA and DNA helices. We find that MD simulations capture the RNA structural change that occurs due to addition of CoHex.

  16. CCLIBS: The CERN Power Converter Control Libraries

    AUTHOR|(SzGeCERN)404953; Lebioda, Krzysztof Tomasz; Magrans De Abril, Marc; Martino, Michele; Murillo Garcia, Raul; Nicoletti, Achille

    2015-01-01

    Accurate control of power converters is a vital activity in large physics projects. Several different control scenarios may coexist, including regulation of a circuit’s voltage, current, or field strength within a magnet. Depending on the type of facility, a circuit’s reference value may be changed asynchronously or synchronously with other circuits. Synchronous changes may be on demand or under the control of a cyclic timing system. In other cases, the reference may be calculated in real-time by an outer regulation loop of some other quantity, such as the tune of the beam in a synchrotron. The power stage may be unipolar or bipolar in voltage and current. If it is unipolar in current, it may be used with a polarity switch. Depending on the design, the power stage may be controlled by a firing angle or PWM duty-cycle reference, or a voltage or current reference. All these cases are supported by the CERN Converter Control Libraries (CCLIBS). These open-source C libraries include advanced reference generati...

  17. Docosahexaenoic acid reverses cyclosporin A-induced changes in membrane structure and function.

    Thakkar, R R; Wang, O L; Zerouga, M; Stillwell, W; Haq, A; Kissling, R; Pierce, W M; Smith, N B; Miller, F N; Ehringer, W D

    2000-04-01

    The use of a fish oil vehicle for cyclosporin A (CsA) can decrease the toxic effects of CsA but the mechanism is unclear. Here we examine the mechanism by which docosahexaenoic acid (DHA), a fish oil-derived polyunsaturated fatty acid, can alter the toxic effects of CsA on mouse organ function, endothelial macromolecular permeability, and membrane bilayer function. Mice given CsA and fish oil showed increased liver toxicity, kidney toxicity, incorporation of DHA, and evidence of oxidized fatty acids compared to control animals. We hypothesized that the toxic effects of CsA were primarily a result of membrane perturbation, which could be decreased if DHA were not oxidized. The presence of CsA (10 mol%) alone increased dipalmitoylphosphatidylcholine membrane permeability by seven fold over control (no CsA, no DHA). However, if non-oxidized DHA (15 mol%) and CsA were added to the membrane, the permeability returned to control levels. Interestingly, if the DHA was oxidized, the antagonistic effect of DHA on CsA was completely lost. While CsA alone increased endothelial permeability to albumin, the combination of non-oxidized DHA and CsA had no effect on endothelial macromolecular permeability. However the combination of oxidized DHA and CsA was no different than the effects of CsA only. CsA increased the fluorescence anisotropy of DPH in the liquid crystalline state of DPPC, while DHA decreased fluorescence anisotropy. However the combination of CsA and DHA was no different than DHA alone. We conclude that non-oxidized DHA can reverse the membrane perturbing effects of CsA, and the increases in endothelial macromolecular permeability, which may explain how fish oil is capable of decreasing the toxicity of CsA. PMID:10742598

  18. Radiated EMI from power converters

    Arnautovski-Toševa Vesna

    2005-01-01

    Full Text Available With the continuous increase of switching frequency together with the ongoing trend to higher complexity and functionality, power converters as a part of electronic systems have raised more and more electromagnetic energy pollution to the local system environment. In the same time, stringent demands are imposed on the designers of new circuits that electromagnetic interference (EMI has to be suppressed at its source before it is allowed to propagate into other circuits and systems. In this paper, the authors present a full-wave numerical method for calculation and simulation of electromagnetic field radiated by power converter circuitry. The main objective is to analyze the layout geometry in order to obtain competitive PCB layout that will enable suitably attenuated level of the radiated electric field to safe level. By this it would be possible to ensure reliable operation of the sensitive electronic components in the proximity.

  19. Vibration converter with magnetic levitation

    Gladilin, A. V.; Pirogov, V. A.; Golyamina, I. P.; Kulaev, U. V.; Kurbatov, P. A.; Kurbatova, E. P.

    2015-05-01

    The paper presents a mathematical model, the results of computational and theoretical research, and the feasibility of creating a vibration converter with full magnetic levitation in the suspension of a high-temperature superconductor (HTSC). The axial and radial stability of the active part of the converter is provided by the interaction of the magnetic field of ring-shaped permanent magnets and a hollow cylinder made of the ceramic HTSC material. The force is created by a system of current-carrying coils whose magnetic field is polarized by permanent magnets and interacts with induced currents in the superconducting cylinder. The case of transition to the superconducting state of HTSC material in the field of the permanent magnets (FC mode) is considered. The data confirm the outlook for the proposed technical solutions.

  20. Photoelectric converters with quantum coherence

    Su, Shan-He; Sun, Chang-Pu; Li, Sheng-Wen; Chen, Jin-Can

    2016-05-01

    Photon impingement is capable of liberating electrons in electronic devices and driving the electron flux from the lower chemical potential to higher chemical potential. Previous studies hinted that the thermodynamic efficiency of a nanosized photoelectric converter at maximum power is bounded by the Curzon-Ahlborn efficiency ηCA. In this study, we apply quantum effects to design a photoelectric converter based on a three-level quantum dot (QD) interacting with fermionic baths and photons. We show that, by adopting a pair of suitable degenerate states, quantum coherences induced by the couplings of QDs to sunlight and fermion baths can coexist steadily in nanoelectronic systems. Our analysis indicates that the efficiency at maximum power is no longer limited to ηCA through manipulation of carefully controlled quantum coherences.

  1. Reducing catalytic converter pressure loss

    NONE

    1996-06-01

    This article examines why approximately 30--40% of total exhaust-system pressure loss occurs in the catalytic converter and what can be done to reduce pressure loss. High exhaust-system backpressure is of concern in the design of power trains for passenger cars and trucks because it penalizes fuel economy and limits peak power. Pressure losses occur due to fluid shear and turning during turbulent flow in the converter headers and in entry separation and developing laminar-flow boundary layers within the substrate flow passages. Some of the loss mechanisms are coupled. For example, losses in the inlet header are influenced by the presence of the flow resistance of a downstream substrate. Conversely, the flow maldistribution and pressure loss of the substrate(s) depend on the design of the inlet header.

  2. Collector for thermionic energy converter

    An improved collector is provided for a thermionic energy converter. The collector comprises a p-type layer of a semiconductor material formed on an n-type layer of a semiconductor material. The p-n junction is maintained in a forward biased condition. The electron affinity of the exposed surface of the p-type layer is effectively lowered to a low level near zero by the presence of a work function lowering activator. The dissipation of energy during collection is reduced by the passage of electrons through the p-type layer in the metastable conduction band state. A significant portion of the electron current remains at the potential of the fermi level of the n-type layer rather than dropping to the fermi level of the p-type layer. Less energy is therefore dissipated as heat and a higher net power output is delivered from a thermionic energy converter incorporating the collector

  3. CHANGES IN SELECTIVITY OF GAMMA-AMINOBUTYRIC ACID FORMATION EFFECTED BY FERMENTATION CONDITIONS AND MICROORGANISMS RESOURCES

    Kamila Kovalovská; Róbert Mazur; Jozef Hudec

    2011-01-01

    In this study we observe the effect of fermentation conditions and resources of microorganisms for production of γ-aminobutyric acid (GABA). The content of produced GABA depends on various conditions such as the amount of precursor, an addition of salt, enzyme and the effect of pH. The highest selectivity of GABA (74.0 %) from the precursor (L-monosodium glutamate) has been determinate in the follow conditions: in the presence of pre-cultured microorganisms from Encián cheese in amount 1.66 %...

  4. Changes in amino acids and some enzymes in rats after chronic sublethal dose of malathion

    Same biochemical effects of the repeated administration of malathion at a sublethal level (137.5 mg/kg) to rats were studied over 40 days. The acute oral LD50 of malathion to male rats is 1375 mg/kg. The insecticide caused disturbances in amino acids and ammonia concentration in brain and liver as compared with the control rats, also inhibited brain and red blood cells acetylcholinesterase (AChE), plasma cholinesterase (ChE) and liver succunic dehydrogenase significantly. Maximum inhibition of blood acetylcholinesterase was noticed after 6 hours of malathion exposure at the level of 137.5 mg/kg

  5. Exogenously Applied Jasmonic Acid Induces Changes in Apical Meristem Morphology of Potato Stolons

    CENZANO, ANA; Vigliocco, Ana; Kraus, Teresa; ABDALA, GUILLERMINA

    2003-01-01

    Hooked apex stolons and initial swelling stolons of potato plants were treated with 3 × 10–8 mol l–1 jasmonic acid (JA) to study the effect of this compound on histology, cell expansion and tissue differentiation. In hooked apex stolons, JA application increased the meristem thickness and reduced the length of the leaf primordia, whereas in initial swelling stolons narrowing of the apical region, absence of leaf primordia and swelling of the subapical meristem were evident. Early vascular tis...

  6. Change of glutamic acid decarboxylase antibody and protein tyrosine phosphatase antibody in Chinese patients with acute-onset type 1 diabetes mellitus

    CHAO Chen; HUANG Gan; LI Xia; YANG Lin; LIN Jian; JIN Ping; LUO Shuo-ming

    2013-01-01

    Background Glutamic acid decarboxylase antibody (GADA) and protein tyrosine phosphatase antibody (IA-2A) are two major autoantibodies,which exert important roles in the process of type 1 diabetes mellitus (T1D).Our study aimed to investigate the changes in positivity and titers of GADA and IA-2A during the course of Chinese acute-onset T1D patients and their relationships with clinical features.Methods Two hundreds and forty-seven Chinese newly diagnosed acute-onset T1D patients were consecutively recruited.GADA and IA-2A were detected at the time of diagnosis,one year later,3-5 years later after diagnosis during the follow-up; all the clinical data were recorded and analyzed as well.Results During the course of acute-onset T1D,the majority of patients remained stable for GADA or IA-2A,however,a few patients changed from positivity to negativity and fewer patients converted from negativity to positivity.The prevalence of GADA was 56.3% at diagnosis,decreasing to 50.5% one year later,and 43.3% 3-5 years later while the corresponding prevalence of IA-2A were 32.8%,31.0% and 23.3%,respectively.The median GADA titers were 0.0825 at diagnosis,declining to 0.0585 one year later and 0.0383 3-5 years later (P <0.001),while the corresponding median titers were 0.0016,0.0010,0.0014 for IA-2A,respectively.Fasting C-peptide (FCP) and postprandial C-peptide 2 hours (PCP2h)levels of GADA or IA-2A negativity persistence patients were higher than those of positivity persistence and negativity conversion patients (P <0.05) which indicated GADA or IA-2A negativity persistence T1D patients had a less loss of β cell function.Conclusion Our data suggest that repeated detection of GADA and IA-2A are necessary for differential diagnosis of autoimmune diabetes and the indirect prediction of the β cell function in Chinese patients.

  7. Combined catalytic converter and afterburner

    Ma, T.T.-H.

    1994-11-30

    This patent describes the combined use of a catalytic converter and afterburner. An afterburner chamber and a catalyst matrix are disposed in series within a casing. A combustible premixed charge is ignited in the afterburner chamber before it enters the catalyst matrix. This invention overcomes the problem encountered in previous designs of some of the premixed charge passing unreacted through the device unless a very long afterburner chamber is used. (UK)

  8. Radiated EMI from power converters

    Arnautovski-Toševa Vesna; Rousset Yanis; Drissi El Khamlichi Khalil; Grčev Leonid

    2005-01-01

    With the continuous increase of switching frequency together with the ongoing trend to higher complexity and functionality, power converters as a part of electronic systems have raised more and more electromagnetic energy pollution to the local system environment. In the same time, stringent demands are imposed on the designers of new circuits that electromagnetic interference (EMI) has to be suppressed at its source before it is allowed to propagate into other circuits and systems. In this p...

  9. EMI Prediction of Switching Converters

    Trinchero, Riccardo; Stievano, Igor Simone; Canavero, Flavio

    2015-01-01

    This paper addresses the simulation of the conducted electromagnetic interference produced by circuits with periodically switching elements. The proposed method allows for the computation of their steady-state responses by means of augmented linear time-invariant equivalents built from circuit inspection only, and standard tools for circuit analysis. The approach is demonstrated on a real dc-dc boost converter by comparing simulation results with real measurements

  10. Development of a Compact Matrix Converter

    J. Bauer

    2009-01-01

    Full Text Available This paper deals with the development of a matrix converter. Matrix converters belong to the category of direct frequency converters. A converter does not contain DC-link and the output voltage is provided by direct switching of voltage from the input phases. This is enabled by 9 bidirectional switches, which are provided by anti-serial connection of 18 IGBT transistors. The absence of a DC-link is great advantage of the matrix converter, but it also increases the requirements on the converter control. For this reason a new prototype of a matrix converter is being developed with sophisticated modern components (FPGA, Power PC equipped in the control part of the converter. The converter will be used for testing new control algorithms and commutation methods. 

  11. Computerized simulation of converter process

    Jalkanen, H.; Suomi, M.L.; Wallgren, M. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Metallurgy

    1996-12-31

    Converter process is essentially an oxidising refining process aiming in addition to (1) the primary refining action, decarburisation of high carbon iron melt, also to (2) maximal elimination of impurity elements, especially silicon, phosphorus and sulphur, (3) melting of substantial amounts of scrap using the extra heat released in oxidation reactions and (4) to exact final steel temperature control, optimal for further treatments. `Quantitative modelling of such a complex non-stationary chemical process as oxygen converting necessitates extensive formulation of chemical and thermal evolution of the process in connection with the technological properties of the reactor and the process control measures. A comprehensive converter simulation program like CONSIM-3. 1 and its preceding versions that is based on the theoretical and practical knowledge on the process can be used for (1) educating specialists and smelter personnel, (2) planning of the blowing programs, (3) developing and testing of process control systems and after some elaboration and restructuring (4) it can be integrated to static or dynamic process control systems. (orig.) SULA 2 Research Programme; 10 refs.

  12. Changes in oxidative properties of Kalanchoe blossfeldiana leaf mitochondria during development of Crassulacean acid metabolism.

    Rustin, P; Queiroz-Claret, C

    1985-06-01

    Kalanchoe blossfeldiana plants grown under long days (16 h light) exhibit a C3-type photosynthetic metabolism. Switching to short days (9 h light) leads to a gradual development of Crassulacean acid metabolism (CAM). Under the latter conditions, dark CO2 fixation produces large amounts of malate. During the first hours of the day, malate is rapidly decarboxylated into pyruvate through the action of a cytosolic NADP(+)-or a mitochondrial NAD(+)-dependent malic enzyme. Mitochondria were isolated from leaves of plants grown under long days or after treatment by an increasing number of short days. Tricarboxylic acid cycle intermediates as well as exogenous NADH and NADPH were readily oxidized by mitochondria isolated from the two types of plants. Glycine, known to be oxidized by C3-plant mitochondria, was still oxidized after CAM establishment. The experiments showed a marked parallelism in the increase of CAM level and the increase in substrate-oxidation capacity of the isolated mitochondria, particularly the capacity to oxidize malate in the presence of cyanide. These simultaneous variations in CAM level and in mitochondrial properties indicate that the mitochondrial NAD(+)-malic enzyme could account at least for a part of the oxidation of malate. The studies of whole-leaf respiration establish that mitochondria are implicated in malate degradation in vivo. Moreover, an increase in cyanide resistance of the leaf respiration has been observed during the first daylight hours, when malate was oxidized to pyruvate by cytosolic and mitochondrial malic enzymes. PMID:24249613

  13. Effect of dietary fatty acid intake on prospective weight change in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition

    Nimptsch, Katharina; Berg-Beckhoff, Gabi; Linseisen, Jakob

    2010-01-01

    . RESULTS: Stearic acid intake was linearly associated with weight gain (P <0.01) in men and women. Linear associations also existed for ALA and arachidonic acid intake, significantly so in women. In multinomial models, women in the highest tertile of ALA and stearic acid intake showed increased OR (95 % CI......OBJECTIVE: To evaluate the association between fatty acid (alpha-linolenic acid (ALA), EPA, DHA, palmitic, stearic, oleic, linoleic and arachidonic acids) intake and prospective weight change in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition. DESIGN...... categorised into four groups (weight loss, or =2.5 to or =7.5%/5 years). Energy-adjusted dietary fatty acid intake data were estimated from the FFQ completed at baseline. Multivariate linear regression models as well as multinomial logistic regression analyses (carbohydrate replacement models) were conducted...

  14. Rapid switch of hepatic fatty acid metabolism from oxidation to esterification during diurnal feeding of meal-fed rats correlates with changes in the properties of acetyl-CoA carboxylase, but not of carnitine palmitoyltransferase I.

    Moir, A M; Zammit, V A

    1993-01-01

    The effects of the ingestion of a meal on the partitioning of hepatic fatty acids between oxidation and esterification were studied in vivo for meal-fed rats. The time course for the reversal of the starved state was extremely rapid and the process was complete within 2 h, in marked contrast with the reversal of the effects of starvation in rats fed ad libitum [A. M. B. Moir and V. A. Zammit (1993) Biochem. J. 289, 49-55]. This rapid reversal occurred in spite of the fact that, in the liver of the meal-fed animals before feeding, a similar degree of partitioning of fatty acids in favour of oxidation was observed as in 24 h-starved rats (previously fed ad libitum). This suggested that the lower degree of ketonaemia observed in meal-fed rats before a meal is not due to the inability of acylcarnitine formation to compete successfully with esterification of fatty acids to the glycerol moiety. Investigation of the possible mechanisms that could contribute towards the rapid switching-off of fatty acid oxidation revealed that this was correlated with a very rapid rise and overshoot in hepatic malonyl-CoA concentration, but not with any change in the activity, or sensitivity to malonyl-CoA, of the mitochondrial overt carnitine palmitoyltransferase (CPT I). The role of these two parameters in the reversal of fasting-induced hepatic fatty acid oxidation was thus the inverse of that observed previously for refed 24 h-starved rats. The rapid increase in [malonyl-CoA] was accompanied by an immediate and complete reversion of the kinetic characteristics (Ka for citrate, expressed/total activity ratio) of acetyl-CoA carboxylase to those found in the post-meal animals, again in contrast with the time course observed in refed 24 h-starved rats [A. M. B. Moir and V. A. Zammit (1990) Biochem. J. 272, 511-517]. The rapidity with which these changes occurred was specific to the partitioning of acyl-CoA; the meal-induced diversion of glycerolipids towards phospholipid synthesis and the

  15. Simulation Results of Double Forward Converter

    P. Vijaya KUMAR

    2009-12-01

    Full Text Available This work aims to find a better forward converter for DC to DC conversion.Simulation of double forward converter in SMPS system is discussed in this paper. Aforward converter with RCD snubber to synchronous rectifier and/or to current doubleris also discussed. The evolution of the forward converter is first reviewed in a tutorialfashion. Performance parameters are discussed including operating principle, voltageconversion ratio, efficiency, device stress, small-signal dynamics, noise and EMI. Itscircuit operation and its performance characteristics of the forward converter with RCDsnubber and double forward converter are described and the simulation results arepresented.

  16. Influence of liposomal muramyl tripeptide phosphatidylethanolamine on changes of nucleic acids in the blood and hemopoietic tissues of irradiated mice

    Influence of liposomal muramyl tripeptide phosphatidylethanolamine (MTP-PE/MLV) on nucleic acid content, and on DNA synthesis and cellularity in the blood and haemopoietic tissues of mice irradiated with a dose of 6 Gy gamma radiation were studied. It was found that injection MTP-PE/MLV alone (200 μg per mouse; i.p.) resulted in a mild decrease in DNA content in the bone marrow as consequence of cellularity diminution in the femur. At the same time, incorporation of 3H-thymidine into bone marrow DNA increased in comparison to the non-stimulated mice. On the basis of simultaneous increase in RNA and DNA concentration in the blood we assume that the changes of nucleic acids and cellularity in the bone marrow of MTP-PE/MLV treated mice are related to the higher release of nuclear cells into the circulation. In mice irradiated 24 h after MTP-PE/MLV injection the decrease in nucleic acid content was similar to that in unprotected mice within the first three days after irradiation. However, during following days, the recovery of RNA and DNA content and cellularity in the bone marrow and blood proceeded at a much faster rate in mice protected at a much faster rate in mice protected by MTP-PE/MLV as compared to unprotected animals. The increase in DNA synthesis in the bone marrow of protected the DNA content recovery. In the spleen and the thymus, no effect of liposomal MTP-PE was found. (author)

  17. Inferences from protein and nucleic acid sequences - Early molecular evolution, divergence of kingdoms and rates of change

    Dayhoff, M. O.; Barker, W. C.; Mclaughlin, P. J.

    1974-01-01

    Description of new sensitive, objective methods for establishing the probable common ancestry of very distantly related sequences and the quantitative evolutionary change which has taken place. These methods are applied to four families of proteins and nucleic acids and evolutionary trees will be derived where possible. Of the three families containing duplications of genetic material, two are nucleic acids: transfer RNA and 5S ribosomal RNA. Both of these structures are functional in the synthesis of coded proteins, and prototypes must have been present in the cell at the inception of the fundamental coding process that all living things share. There are many types of tRNA which recognize the various nucleotide triplets and the 20 amino acids. These types are thought to have arisen as a result of many gene duplications. Relationships among these types are discussed. The 5S ribosomal RNA, presently functional in both eukaryotes and prokaryotes, is very likely descended from an early form incorporating almost a complete duplication of genetic material. The amount of evolution in the various lines can again be compared. The other two families containing duplications are proteins; ferredoxin and cytochrome c.

  18. Changes of the Biomass and Acid Phosphatase Activity in Maize (Zea mays L.) Lines Under Low-P Stress

    YAO Qilun

    2008-01-01

    A pot culture trial was conducted to investigate the changes of the biomass and acid phosphatase (APase) activity in 10 maize lines under low-P stress. P-deficiency significantly decreased the biomass, but induced the significant enhancement of the APase activity. Since P-deficiency had smaller effects on the low-P tolerant maize lines compared with P-sensitive lines, it was demonstrated that differences of tolerance to P-deficiency existed among 10 different maize lines. In addition, the relative biomass and APase activity changed during the vegetative stage of development, and there existed a significant correlation between the biomass and APase activity under low-P stress. These results suggest that the biomass and APase activity can be regarded as indicative traits of maize lines for tolerance to low-P stress at seedling stage.

  19. Salicylic acid induced physiological and biochemical changes in wheat under drought stress conditions

    Experiment for finding the effect of pre-soaking of wheat seeds varieties, viz Wafaq-2001 and Punjab-96, in salicylic acid (SA) solution on the drought tolerance of wheat, revealed increase in the total biomass and grain yield per plant as well as in spikes per plant, 100 seed weight, proline, total soluble sugars, membrane stability index (MSI), superoxide dismutase (SOD) and ascorbate peroxidase (APOX) activity in both the tested varieties. The yield increase in drought tolerant variety Wafaq-2001 was more as compared to drought sensitive Punjab-96. Results signify the role of SA in regulating the drought response of wheat and that SA could be seed primed and used as a potential growth regulator under drought stress conditions. (author)

  20. Changes in serum concentration of N-acetylneuraminic acid in patients with bladder carcinoma during radiotherapy

    The N-acetylneuraminic acid (N-ANA) concentration of serum in 24 patients with bladder carcinoma was measured with a modified Arzneibuch (D.L.) GDR-method before, during and after the postoperative radiotherapy. It was found that the N-ANA-concentrations in the patients operated resulted in a dependence from tumor staging already before the radiotherapy. The N-ANA concentration raised with increased staging. A temporary enhancement of the N-ANA-concentration with the maximum between 20. and 25. radiation fractions occurred in patients of staging T3 and relapses as well as with tumor cells being only little differentiated. The results are discussed in relation to the clinical importance. (orig.)

  1. Changing of network characteristics of acrylamide/maleic acid hydrogels by alteration of irradiation dose rate

    Poly(acrylamide/maleic acid) P(AAm/MA) hydrogels were prepared by irradiating the ternary mixtures of AAm/MA and water by gamma rays at ambient temperature at very low (0.18 kGy/h), and moderate dose rate (3.0 kGy/h). The equilibrium degree of swelling (EDS) of hydrogels prepared at 3.0 kGy/h dose rate increased from 520% to 3900% with increasing MA mole content in the gel system from 0% to 5.2%. On the other hand, no systematic dependence of swelling on MA content was observed for hydrogels obtained at low dose rate irradiation due to formation of inhomogeneous network structure and large pores in the gel. Pore structure of hydrogels was monitored by using scanning electron microscope. Systematic swelling of P(AAm/MA) hydrogels prepared at moderate dose rates can be explained with homogeneous pore size distribution of network

  2. Seasonal changes in the fatty acid profile of the tick Ixodes ricinus (Acari, Ixodidae).

    Cuber, Piotr; Urbanek, Aleksandra; Naczk, Aleksandra; Stepnowski, Piotr; Gołębiowski, Marek

    2016-06-01

    Fatty acids (FAs) from nymphs, females and males of Ixodes ricinus were analysed by gas chromatography/mass spectrometry. Ticks were collected from May to October 2013. The most abundant FAs were 18:1, 18:0, 16:0 and 18:2 which are also dominant FAs of insects. Adults contained higher concentrations of FAs in general than nymphs because they contain more fat body and probably a thicker layer of epicuticular lipids. Larger quantities of FAs > 20 carbon atoms in the carboxylic chain were present in females, which generally show higher content of lipids essential for oogenesis, whereas there were similar amounts of 14-18 in both sexes. In September and October, ticks contained large concentrations of the majority of FAs except for 18:1, the most abundant one in ticks collected from May through August. Thus, most FAs, especially those with more than 20 C atoms, tend to increase at lower temperatures. PMID:26976134

  3. Changes of endogenous antioxidants and fatty acid composition in irradiated rice bran during storage

    The effects of gamma-irradiation (5, 10, and 15 kGy) on antioxidants and lipid composition of rice bran were studied. The free fatty acid (FFA) level in rice bran irradiated at 5 kGy was not significantly different from that of raw rice bran. Increases in irradiation doses to 10 and 15 kGy resulted in an increase in FFA levels. gamma-irradiation at 15 kGy resulted in greater (p less than or equal to 0.05) loss of phospholipids in rice bran during storage. Also, gamma-irradiation had deleterious effects on lipid stability, E vitamers, and oryzanol in rice bran during irradiation and subsequent storage. The decomposition of individual E vitamers increased with an increase in irradiation level. The loss of total E vitamers and oryzanol occurred in two stages: 50-82% and 12-33% immediately following irradiation and a further 10-35% and 39-42% during storage

  4. Changes in unbound and total valproic acid concentrations after replacement of carbamazepine with oxcarbazepine.

    Battino, D; Croci, D; Granata, T; Bernardi, G; Monza, G

    1992-10-01

    Total and free valproic acid (VPA) concentrations were measured in patients switched from a combined VPA and carbamazepine (CBZ) to a combined VPA and oxcarbazepine (OXC) therapy, both administered in individualized daily doses. Four young epileptic patients (13-17 years old) were studied for a 12-week period, total and free VPA concentrations being analyzed just before and 4 h after the morning dose, at the end of VPA and CBZ therapy, and 2 and 10 weeks after CBZ was replaced by OXC. The expected increase in the level/dose (L/D) ratio of total VPA observed at the end of the study was preceded by a clear-cut increase in the L/D ratio of free VPA, which led to VPA-related side effects and required the retitration of VPA daily doses. PMID:1448844

  5. Interactions between major chlorogenic acid isomers and chemical changes in coffee brew that affect antioxidant activities.

    Liang, Ningjian; Xue, Wei; Kennepohl, Pierre; Kitts, David D

    2016-12-15

    Coffee bean source and roasting conditions significantly (p<0.05) affected the content of chlorogenic acid (CGA) isomers, several indices of browning and subsequent antioxidant values. Principal component analysis was used to interpret the correlations between physiochemical and antioxidant parameters of coffee. CGA isomer content was positively correlated (p<0.001) to capacity of coffee to reduce nitric oxide and scavenge Frémy's salt. Indices of browning in roasted coffee were positively correlated (p<0.001) to ABTS and TEMPO radical scavenging capacity, respectively. Only the CGA content of coffee corresponded to intracellular antioxidant capacity measured in Caco-2 intestinal cells. This study concluded that the intracellular antioxidant capacity that best describes potential health benefits of coffee positively corresponds best with CGA content. PMID:27451179

  6. The influence of GDL concentration on milk pH change during acid coagulation

    Fetahagić Safet

    2002-01-01

    Full Text Available Skim milk powder was reconstituted to obtain milk A (with 8.01% TS. Milk A was standardized with 3% of skim milk powder and 3% of demineralized whey powder (DWP, respectively, to obtain milk B (with 11.15% TS and milk C (with 11.10% TS. Milk samples were heat treated at 85ºC/10 min, 90ºC/10 min and 95ºC/10 min, respectively. Untreated milk was used as control. Acidification was carried out at 25ºC, 35ºC and 45ºC during 240 min with GDL (glucono-d-lactone, namely with the amount of 0.5%, 0.75%, 1.0%, 1.25% 1.5%, 1.75%, 2.0% and 3.0% of GDL, respectively. The results showed that all investigated factors, explicitly GDL concentration, acidification temperature and applied heat treatment of milk as well as added DWP influence the change of pH during acidification. Milk samples standardized with DWP had smaller buffer capacity and faster change of pH than samples standardized with skim milk powder. Only at acidification temperature of 25ºC, added DWP did not influence the change of milk buffer capacity regardless of the change of casein:whey protein ratio. Under this acidification condition, both milk samples standardized with skim milk powder and DWP had similar final pH values.

  7. Impacts of changing food webs in Lake Ontario: Implications of dietary fatty acids on growth of alewives

    Snyder, R.J.; Demarche, C.J.; Honeyfield, D.C.

    2011-01-01

    Declines in the abundance and condition of Great Lakes Alewives have been reported periodically during the last two decades, and the reasons for these declines remain unclear. To better understand how food web changes may influence Alewife growth and Wisconsin growth model predictions, we fed Alewives isocaloric diets high in omega-6 fatty acids (corn oil) or high in omega-3 fatty acids (fish oil). Alewives were fed the experimental diets at either 1% ("low ration") or 3% ("high ration") of their wet body weight per day. After six weeks, Alewives maintained on the high ration diets were significantly larger than those fed the low ration diets. Moreover, Alewives given the high ration fish oil diet were significantly larger than those maintained on the high ration corn oil diet after six weeks of growth. Body lipid, energy density and total body energy of Alewives on the high ration diets were significantly higher than those fed the low ration diets, and total body energy was significantly higher in Alewives given the high ration fish oil diet compared to those on the high ration corn oil diet. The current Wisconsin bioenergetics model underestimated growth and overestimated food consumption by Alewives in our study. Alewife thiaminase activity was similar among treatment groups. Overall, our results suggest that future food web changes in Lake Ontario, particularly if they involve decreases in the abundance of lipid rich prey items such as Mysis, may reduce Alewife growth rates and total body energy due to reductions in the availability of dietary omega-3 fatty acids. ?? 2011 AEHMS.

  8. Design of a Fully Integrated Three-Level Buck Converter

    Y. Neelima*,

    2014-08-01

    Full Text Available Dynamic response of a converter plays an important role in many applications which change load in a rapid manner, especially in POL (Point of load applicant ions. Here a new method for improving the dynamic response of a converter is presented. Here separate control schemes are implemented during steady state as well as transient load conditions. A three level buck converter topology with fast transient response is discussed here. This topology does not require a soft start up circuitry for three level buck converters. Simulation model is done in Matlab/Simulink and the result shows a great improvement in dynamic response of the system. The 3-level converter enables smaller inductors (1 NH than a buck, while generating a wide range of output voltages compared to a 1/2 model capacitor converter. The test-chip prototype delivers up to 0.85 a load current while generating output voltages from 0.4 to 1.4 V from a 2.4 V input supply. It achieves 77% peak efficiency at power density of 0.1 W/mm and 63% efficiency at maximum power density of 0.3 W/mm.

  9. A MEMS Interface IC With Low-Power and Wide-Range Frequency-to-Voltage Converter for Biomedical Applications.

    Arefin, Md Shamsul; Redouté, Jean-Michel; Yuce, Mehmet Rasit

    2016-04-01

    This paper presents an interface circuit for capacitive and inductive MEMS biosensors using an oscillator and a charge pump based frequency-to-voltage converter. Frequency modulation using a differential crossed coupled oscillator is adopted to sense capacitive and inductive changes. The frequency-to-voltage converter is designed with a negative feedback system and external controlling parameters to adjust the sensitivity, dynamic range, and nominal point for the measurement. The sensitivity of the frequency-to-voltage converter is from 13.28 to 35.96 mV/MHz depending on external voltage and charging current. The sensitivity ranges of the capacitive and inductive interface circuit are 17.08 to 54.4 mV/pF and 32.11 to 82.88 mV/mH, respectively. A capacitive MEMS based pH sensor is also connected with the interface circuit to measure the high acidic gastric acid throughout the digestive tract. The sensitivity for pH from 1 to 3 is 191.4 mV/pH with 550 μV(pp) noise. The readout circuit is designed and fabricated using the UMC 0.18 μm CMOS technology. It occupies an area of 0.18 mm (2) and consumes 11.8 mW. PMID:26954843

  10. The Effect of Percutaneous Nephrolithotomy Process on Hemodynamic, Electrolyte and Acid-Base Changes

    Ercan Baş

    2015-10-01

    Full Text Available Aim: Operation of percutaneous nephrolithotomy (PNL, is the most commonly used method of renal stone surgery. During this operation, kidney must be continually irrigated with isotonic liquid. In our study, we investigated the volume of irrigation, irrigation duration, input the number of percutaneous renal parenchymal thickness and the degree of this finding the effects of on hemodynamic, electrolyte and metabolic changes. Method: 64 patient with an indication for percutaneous nephrolithotomy were included in the study. Before irrigation, during irrigation and the post- irrigation; pulse, systolic and diastolic blood pressure (bp, electrolytes, arterial blood gases were measured. In preoperative and postoperative 1. and 24. hours hemoglobin, creatinine levels were measured. Before the operation; pelvicaliectasis degree, parenchymal thickness, volume and duration of irrigation and the number of percutaneous entry were recorded in all patients. Results: Following the start of irrigation, changes in diastolic and systolic bp and pulse also not statistically significant. No significant change of partial oxygen, carbon dioxide, and oxygen saturation pressure was observed. After the operation, serum sodium, potassium, calcium values are within normal limits, but when compared with preoperative values the decrease of these values statistically significant were observed. Bicarbonate and ph values with irrigation period had a negative correlation. Although not clinically significant parenchymal thickness was found to be negative correlation with decrease of calcium. Additionally degrees of pelvicaliectasis has been found negative correlation with the decrease of sodium and bicarbonate. Conclusion: Hemodynamics and electrolytes did not change significantly both during and after the PNL process, but metabolic acidosis was observed towards the end of the PNL process. In long-term irrigation, repeated percutaneous entrances, people with moderate and severe

  11. Structural changes of polyacids initiated by their neutralization with various alkali metal hydroxides. Diffusion studies in poly(acrylic acid)s.

    Masiak, Michal; Hyk, Wojciech; Stojek, Zbigniew; Ciszkowska, Malgorzata

    2007-09-27

    The changes in the three-dimensional structure of the poly(acrylic acid), PAA, induced by incorporation of various alkali-metal counterions have been evaluated by studying diffusion of an uncharged probe (1,1'-ferrocenedimethanol) in the polymeric media. The studies are supported by the measurements of conductivity and viscosity of the polymeric media. Solutions of linear PAA of four different sizes (molecular weights: 450,000, 750,000, 1,250,000, 4,000,000) were neutralized with hydroxides of alkali metals of group 1 of the periodic table (Li, Na, K, Rb, Cs) to the desired neutralization degree. The transport properties of the obtained polyacrylates were monitored by measuring the changes in the probe diffusion coefficient during the titration of the polyacids. The probe diffusivity was determined from the steady-state current of the probe voltammetric oxidation at disk microelectrodes. Diffusivity of the probe increases with the increase in the degree of neutralization and with the increase in viscosity. It reaches the maximum value at about 60-80% of the polyacid neutralization. The way the probe diffusion coefficients change is similar in all polyacid solutions and gels. The increase in the size of a metal cation causes, in general, an enhancement in the transport of probe molecules. The biggest differences in the probe diffusivities are between lithium and cesium polyacrylates. The differences between the results obtained for cesium and rubidium are not statistically significant due to lack of good precision of the voltammetric measurements. The measurements of the electric conductivity of polyacrylates and the theoretical predictions supplemented the picture of electrostatic interactions between the polyanionic chains and the metal cations of increasing size. In all instances of the PAAs, the viscosity of the solutions rapidly increases in the 0-60% range of neutralization and then becomes constant in the 60-100% region. With the exception of the shortest

  12. Power electronics converters and regulators

    Dokić, Branko L

    2015-01-01

    This book is the result of the extensive experience the authors gained through their year-long occupation at the Faculty of Electrical Engineering at the University of Banja Luka. Starting at the fundamental basics of electrical engineering, the book guides the reader into this field and covers all the relevant types of converters and regulators. Understanding is enhanced by the given examples, exercises and solutions. Thus this book can be used as a textbook for students, for self-study or as a reference book for professionals.

  13. Power Converters and Power Quality

    Kahle, K

    2015-01-01

    This paper discusses the subject of power quality for power converters. The first part gives an overview of most of the common disturbances and power quality issues in electrical networks for particle accelerators, and explains their consequences for accelerator operation. The propagation of asymmetrical network disturbances into a network is analysed. Quantitative parameters for network disturbances in a typical network are presented, and immunity levels for users’ electrical equipment are proposed. The second part of this paper discusses the technologies and strategies used in particle accelerator networks for power quality improvement . Particular focus is given to networks supplying loads with cycling active and reactive power

  14. Converting pest insects into food

    Offenberg, Hans Joachim; Wiwatwittaya, Decha

    2010-01-01

    pest insects, problematic pests are converted into food and additional earnings. To assess the profitability of providing additional food for the ants, O. smaragdina food conversion efficiency (ECI) was estimated in the laboratory. This estimate suggests the feeding of weaver ants in ant farms to be......Canopy dwelling weaver ants (Oecophylla spp.) are used to control a variety of pests in a number of tropical tree crops. What is less familiar is the existence of commercial markets where these ants and their brood are sold for (i) human consumption, (ii) pet food or (iii) traditional medicine. In...

  15. Analysis Of Single Phase Matrix Converter

    Divya Ahirrao; Bhagyashri Gaware

    2014-01-01

    This paper presents concept of single phase matrix converter. Single phase matrix converter (SPMC) performs a function such as frequency changer, rectifier, inverter; chopper. This reduces the need for new converter hardware. Pulse width modulation (SPWM) techniques are used to calculate the switch duty ratio to synthesis the output. The simulation of converter is carried out in MATLAB/SIMULINK. Hardware design is obtained using readily available IC‟s and other components. Thi...

  16. Valuing Convertible Bonds Based on LSRQM Method

    Jian Liu; Lizhao Yan; Chaoqun Ma

    2014-01-01

    Convertible bonds are one of the essential financial products for corporate finance, while the pricing theory is the key problem to the theoretical research of convertible bonds. This paper demonstrates how to price convertible bonds with call and put provisions using Least-Squares Randomized Quasi-Monte Carlo (LSRQM) method. We consider the financial market with stochastic interest rates and credit risk and present a detailed description on calculating steps of convertible bonds value. The e...

  17. OAM mode converter in twisted fibers

    Usuga Castaneda, Mario A.; Beltran-Mejia, Felipe; Cordeiro, Cristiano;

    2014-01-01

    We analyze the case of an OAM mode converter based on a twisted fiber, through finite element simulations where we exploit an equivalence between geometric and material transformations. The obtained converter has potential applications in MDM. © 2014 OSA.......We analyze the case of an OAM mode converter based on a twisted fiber, through finite element simulations where we exploit an equivalence between geometric and material transformations. The obtained converter has potential applications in MDM. © 2014 OSA....

  18. Simulation Results of Double Forward Converter

    P. Vijaya Kumar; S. Rama Reddy

    2009-01-01

    This work aims to find a better forward converter for DC to DC conversion.Simulation of double forward converter in SMPS system is discussed in this paper. Aforward converter with RCD snubber to synchronous rectifier and/or to current doubleris also discussed. The evolution of the forward converter is first reviewed in a tutorialfashion. Performance parameters are discussed including operating principle, voltageconversion ratio, efficiency, device stress, small-signal dynamics, noise and EMI....

  19. Changes in Biochemical Composition of Mango in Response to Pre-Harvest Gibberellic Acid Spray

    Md Wasim Siddiqui

    2014-01-01

    Full Text Available Mango (Mangifera indica L. is an important fruit of the world owing to its pleasant aroma and taste. In this investigation, the influence of gibberellic acid (GA3 at concentrations of 0, 50, 100 and 150 mg∙l-1 water sprayed 20 days before commercial harvest on postharvest behavior and quality of mango cv. ‘Himsagar’ was studied under ambient storage conditions. GA3 (100 and 150 mg∙l-1 delayed the onset of ripening and caused a reduction in respiration rate as compared to the untreated fruits and retained the total chlorophyll content of fruit peel. Pre-harvest spray of GA3 at 100 mg∙l-1 significantly delayed the onset of the climacteric rise of CO2 production, which depicted delayed ripening over control. The treated fruits also remained firmer and maintained the freshness during storage. Treatment with 100 mg∙l-1 GA3 could be a useful method to extend postharvest life and availability of mango with appreciable quality.

  20. Changes in Biochemical Composition of Mango in Response to Pre-Harvest Gibberellic Acid Spray

    Md Wasim Siddiqui

    2014-03-01

    Full Text Available Mango (Mangifera indica L. is an important fruit of the world owing to its pleasant aroma and taste. In this investigation, the influence of gibberellic acid (GA3 at concentrations of 0, 50, 100 and 150 mg∙l-1 water sprayed 20 days before commercial harvest on postharvest behavior and quality of mango cv. ‘Himsagar’ was studied under ambient storage conditions. GA3 (100 and 150 mg∙l-1 delayed the onset of ripening and caused a reduction in respiration rate as compared to the untreated fruits and retained the total chlorophyll content of fruit peel. Pre-harvest spray of GA3 at 100 mg∙l-1 significantly delayed the onset of the climacteric rise of CO2 production, which depicted delayed ripening over control. The treated fruits also remained firmer and maintained the freshness during storage. Treatment with 100 mg∙l-1 GA3 could be a useful method to extend postharvest life and availability of mango with appreciable quality.

  1. Investigation of change of serum immunosuppressive acidic protein levels in gynecological tumors

    2002-01-01

    Objective: To study the clinical significance for measuring serum immunosuppressive acidic protein(IAP) levels to diagnose and follow up survey patients with the gynecological tumor.Methods: Serum IAP levels were determined by IAP-single radial immunodiffusion test in 235 patients with the gynecological tumor,including 38 cases of benign tumor of ovary,41 cases of malignant tumor of ovary,66 cases of hysteromyoma,34 carcinomas of uterine cervix, 16 endometrial carcinomas,27 cases of chemotherapy,13 cases of recurrence, and the control group was 50 cases health women.Results: Serum IAP level was 889.4±207.8mg/L in malignant ovary tumors,which was significantly higher than that of health women and benign tumors of ovary (P<0.01).In patients with carcinoma of uterine cervix and endometrial carcinoma, their IAP levels were 741.4±212.6mg/L and 763.3±209.4mg/L,which were higher than those of the health women and benign tumor of ovary(P<0.01).After chemotherapy, serum IAP levels of malignant tumor of ovary were decreased;in patients with recurrence of tumor of ovary,IAP levels increased compared with the health women(P<0.01).Incidence of the abnormal value was 100%.Conclusion:Measuring IAP level of the gynecological tumor may be an auxiliary index for monitoring gynecological tumor and identifying benign and malignant tumor.

  2. Dynamic functional characterization and phylogenetic changes due to Long Chain Fatty Acids pulses in biogas reactors.

    Kougias, Panagiotis G; Treu, Laura; Campanaro, Stefano; Zhu, Xinyu; Angelidaki, Irini

    2016-01-01

    The process stability of biogas plants is often deteriorated by the accumulation of Long Chain Fatty Acids (LCFA). The microbial community shifts due to LCFA disturbances have been poorly understood as the molecular techniques used were not able to identify the genome characteristics of uncultured microorganisms, and additionally, the presence of limited number of reference genomes in public databases prevented the comprehension of specific functional roles characterizing these microorganisms. The present study is the first research which deciphers by means of high throughput shotgun sequencing the dynamics of the microbial community during an inhibitory shock load induced by single pulses of unsaturated LCFA at two different concentrations (i.e. 2 g/L-reactor and 3 g/L-reactor). The metagenomic analysis showed that only the microbes associated with LCFA degradation could encode proteins related to "chemotaxis" and "flagellar assembly", which promoted the ability to move towards the LCFA sources so as to degrade them. Moreover, the syntrophic interactions found between Syntrophomonas sp. together with Methanosarcina sp. were possibly assigned to the menaquinone-electron transfer. Finally, it was proven that a previously exposed to LCFA inoculum is more efficient in the degradation process of LCFA due to the specialization of the microbial consortium. PMID:27353502

  3. Changes in Cinnamic Acid Derivatives Associated with the Habituation of Maize Cells to Dichlobenil

    Hugo Mélida; Jesús .(A)lvarez; José Luis Acebes; Antonio Encina; Stephen C. Fry

    2011-01-01

    The habituation of cell cultures to cellulose biosynthesis inhibitors such as dichlobenil (DCB) represents a valuable tool to improve our knowledge of the mechanisms involved in plant cell wall structural plasticity.Maize cell lines habituated to lethal concentrations of DCB were able to grow through the acquisition of a modified cell wall in which cellulose was partially replaced by a more extensive network of arabinoxylans.The aim of this work was to investigate the phenolic metabolism of non-habituated and DCB-habituated maize cell cultures.Maize cell cultures were fed [14C]cinnamate and the fate of the radioactivity in different intra-protoplasmic and wall-localized fractions throughout the culture cycle was analyzed by autoradiography and scintillation counting.Non-habituated and habituated cultures did not markedly differ in their ability to uptake exogenous [14C]cinnamic acid.However,interesting differences were found in the radiolabeling of low- and high-Mr metabolites.Habituated cultures displayed a higher number and amount of radiolabeled low-Mr compounds,which could act as reserves later used for polysaccharide feruloylation.DCB-habituated cultures were highly enriched in esterified [14C]dehydrodiferulates and larger coupling products.In conclusion,an extensive and early cross-linking of hydroxycinnamates was observed in DCB-habituated cultures,probably strengthening their cellulose-deficient walls.

  4. Reversible Burst of Transcriptional Changes during Induction of Crassulacean Acid Metabolism in Talinum triangulare.

    Brilhaus, Dominik; Bräutigam, Andrea; Mettler-Altmann, Tabea; Winter, Klaus; Weber, Andreas P M

    2016-01-01

    Drought tolerance is a key factor for agriculture in the 21st century as it is a major determinant of plant survival in natural ecosystems as well as crop productivity. Plants have evolved a range of mechanisms to cope with drought, including a specialized type of photosynthesis termed Crassulacean acid metabolism (CAM). CAM is associated with stomatal closure during the day as atmospheric CO2 is assimilated primarily during the night, thus reducing transpirational water loss. The tropical herbaceous perennial species Talinum triangulare is capable of transitioning, in a facultative, reversible manner, from C3 photosynthesis to weakly expressed CAM in response to drought stress. The transcriptional regulation of this transition has been studied. Combining mRNA-Seq with targeted metabolite measurements, we found highly elevated levels of CAM-cycle enzyme transcripts and their metabolic products in T. triangulare leaves upon water deprivation. The carbohydrate metabolism is rewired to reduce the use of reserves for growth to support the CAM-cycle and the synthesis of compatible solutes. This large-scale expression dataset of drought-induced CAM demonstrates transcriptional regulation of the C3-CAM transition. We identified candidate transcription factors to mediate this photosynthetic plasticity, which may contribute in the future to the design of more drought-tolerant crops via engineered CAM. PMID:26530316

  5. Reversible Burst of Transcriptional Changes during Induction of Crassulacean Acid Metabolism in Talinum triangulare1[OPEN

    Winter, Klaus

    2016-01-01

    Drought tolerance is a key factor for agriculture in the 21st century as it is a major determinant of plant survival in natural ecosystems as well as crop productivity. Plants have evolved a range of mechanisms to cope with drought, including a specialized type of photosynthesis termed Crassulacean acid metabolism (CAM). CAM is associated with stomatal closure during the day as atmospheric CO2 is assimilated primarily during the night, thus reducing transpirational water loss. The tropical herbaceous perennial species Talinum triangulare is capable of transitioning, in a facultative, reversible manner, from C3 photosynthesis to weakly expressed CAM in response to drought stress. The transcriptional regulation of this transition has been studied. Combining mRNA-Seq with targeted metabolite measurements, we found highly elevated levels of CAM-cycle enzyme transcripts and their metabolic products in T. triangulare leaves upon water deprivation. The carbohydrate metabolism is rewired to reduce the use of reserves for growth to support the CAM-cycle and the synthesis of compatible solutes. This large-scale expression dataset of drought-induced CAM demonstrates transcriptional regulation of the C3–CAM transition. We identified candidate transcription factors to mediate this photosynthetic plasticity, which may contribute in the future to the design of more drought-tolerant crops via engineered CAM. PMID:26530316

  6. Ginger and alpha lipoic acid ameliorate age-related ultrastructural changes in rat liver.

    Mahmoud, Y I; Hegazy, H G

    2016-01-01

    Because of the important role that oxidative stress is thought to play in the aging process, antioxidants could be candidates for preventing its related pathologies. We investigated the ameliorative effects of two antioxidant supplements, ginger and alpha lipoic acid (ALA), on hepatic ultrastructural alterations in old rats. Livers of young (4 months) and old (24 months) Wistar rats were studied using transmission electron microscopy. Livers of old rats showed sinusoidal collapse and congestion, endothelial thickening and defenestration, and inconsistent perisinusoidal extracellular matrix deposition. Aged hepatocytes were characterized by hypertrophy, cytoplasmic vacuolization and a significant increase in the volume densities of the nuclei, mitochondria and dense bodies. Lipofuscin accumulation and decreased microvilli in bile canaliculi and space of Disse also were observed. The adverse alterations were ameliorated significantly by both ginger and ALA supplementation; ALA was more effective than ginger. Ginger and ALA appear to be promising anti-aging agents based on their amelioration of ultrastructural alterations in livers of old rats. PMID:26528730

  7. Changes in free amino acids content in albacore (Thunnus alalunga) muscle during thermal processing.

    Perez-Martin, R I; Franco, J M; Aubourg, S; Gallardo, J M

    1988-11-01

    The effects of cooking and sterilization at several temperatures on the free amino acids (FAA) content in albacore (Thunnus alalunga) muscle were studied during the processing of canned tuna. FAAs were derivatized with o-phthalaldehyde, separated on a C18 column by HPLC and detected by both fluorescence and ultra-violet detectors. After cooking the loss of FAAs was not significant. However, in the final product sterilized at 115 degrees C and 110 degrees C (throughout the whole process) there were significant losses with regard to the start material, but not at 118 degrees C (all temperatures leading to the same lethal F-value). The influence of the thermal process time at 115 degrees C was evaluated for 60 and 100 min. Significant losses were found between both canned products (approximately 25%) and between the raw fish and the final product (approximately 12% and approximately 34%, process time 60 and 100 min, respectively). The determination of the content of FAA present in canned albacore may be a useful indication of the severity of the thermal processing. PMID:3206942

  8. Changes in dynamics upon oligomerization regulate substrate binding and allostery in amino acid kinase family members.

    Enrique Marcos

    2011-09-01

    Full Text Available Oligomerization is a functional requirement for many proteins. The interfacial interactions and the overall packing geometry of the individual monomers are viewed as important determinants of the thermodynamic stability and allosteric regulation of oligomers. The present study focuses on the role of the interfacial interactions and overall contact topology in the dynamic features acquired in the oligomeric state. To this aim, the collective dynamics of enzymes belonging to the amino acid kinase family both in dimeric and hexameric forms are examined by means of an elastic network model, and the softest collective motions (i.e., lowest frequency or global modes of motions favored by the overall architecture are analyzed. Notably, the lowest-frequency modes accessible to the individual subunits in the absence of multimerization are conserved to a large extent in the oligomer, suggesting that the oligomer takes advantage of the intrinsic dynamics of the individual monomers. At the same time, oligomerization stiffens the interfacial regions of the monomers and confers new cooperative modes that exploit the rigid-body translational and rotational degrees of freedom of the intact monomers. The present study sheds light on the mechanism of cooperative inhibition of hexameric N-acetyl-L-glutamate kinase by arginine and on the allosteric regulation of UMP kinases. It also highlights the significance of the particular quaternary design in selectively determining the oligomer dynamics congruent with required ligand-binding and allosteric activities.

  9. Tunable astigmatic π/2 mode converter

    The scheme of a tunable astigmatic π/2 mode converter is described. The converter provides the use of input beams with the twofold variable Rayleigh length, while variations in the optical length of the converter itself do not exceed 1/6. (laser beams)

  10. Ecologically Optimal Solution of Power Semiconductors Converters

    Ivan Lokseninec

    2003-01-01

    Full Text Available One of the relevant scientific programs of Department of Power Electrical Systems is research of ecologically optimal topologies main circuits of power converters. This paper presents some methods how to reduce unfavourable influences of power converters on the grid. The achieved results were applieed in praxis, especially in the power converters produced by Electrotechnical Research and Projecting Institute in Nova Dubnica.

  11. Thermal energy storage properties of mannitol–fatty acid esters as novel organic solid–liquid phase change materials

    Highlights: ► Four kinds of mannitol–fatty acid esters were synthesized as novel organic PCMs for thermal energy storage applications. ► The synthesized PCMs were characterized using FT-IR, 1H NMR, 13C NMR, DSC and TGA methods and thermal cycling test. ► The melting temperatures and latent heat values of the PCMs were in the range of 42–65 °C and 145–202 J/g, respectively. ► Thermal conductivity of the PCMs was increased significantly by addition of EG with especially 10 wt%. ► The synthesized PCMs are promising organic PCMs for solar heating applications. - Abstract: In this study, four kinds of mannitol–fatty acid esters were synthesized as novel organic phase change materials (PCMs) for thermal energy storage applications. The structural characterization of synthesized mannitol hexastearate (MHS), mannitol hexapalmitate (MHP), mannitol hexamyristate (MHM) and mannitol hexalaurate (MHL) were carried out using Fourier Transform Infrared (FT-IR), Proton Nuclear Magnetic Resonance (1H NMR), and 13C NMR spectroscopy methods. Thermal energy storage properties and thermal reliability of the synthesized PCMs were determined using differential scanning calorimetry (DSC) method at a heating rate of 1 °C/min. DSC results showed that the melting temperatures of the PCMs were in the temperature range of 42–65 °C and their latent heat values spanned between 145 and 202 J/g. The latent heats of these PCMs are low compared to mannitol but they fall into the same range as fatty acids. The synthesized PCMs have much lower phase change temperatures and supercooling degree (about 1–8 °C) and compared to the mannitol. They have also better odor, noncorrosivity and thermal durability properties as compared to the fatty acids. Thermal cycling test consisted of repeated 1000 melting/solidification cycles also revealed that the synthesized PCMs have good thermal reliability. In addition, thermal conductivity of the PCMs was increased significantly by addition

  12. Volatile profiling reveals intracellular metabolic changes in Aspergillus parasiticus: veA regulates branched chain amino acid and ethanol metabolism

    Roze Ludmila V

    2010-08-01

    Full Text Available Abstract Background Filamentous fungi in the genus Aspergillus produce a variety of natural products, including aflatoxin, the most potent naturally occurring carcinogen known. Aflatoxin biosynthesis, one of the most highly characterized secondary metabolic pathways, offers a model system to study secondary metabolism in eukaryotes. To control or customize biosynthesis of natural products we must understand how secondary metabolism integrates into the overall cellular metabolic network. By applying a metabolomics approach we analyzed volatile compounds synthesized by Aspergillus parasiticus in an attempt to define the association of secondary metabolism with other metabolic and cellular processes. Results Volatile compounds were examined using solid phase microextraction - gas chromatography/mass spectrometry. In the wild type strain Aspergillus parasiticus SU-1, the largest group of volatiles included compounds derived from catabolism of branched chain amino acids (leucine, isoleucine, and valine; we also identified alcohols, esters, aldehydes, and lipid-derived volatiles. The number and quantity of the volatiles produced depended on media composition, time of incubation, and light-dark status. A block in aflatoxin biosynthesis or disruption of the global regulator veA affected the volatile profile. In addition to its multiple functions in secondary metabolism and development, VeA negatively regulated catabolism of branched chain amino acids and synthesis of ethanol at the transcriptional level thus playing a role in controlling carbon flow within the cell. Finally, we demonstrated that volatiles generated by a veA disruption mutant are part of the complex regulatory machinery that mediates the effects of VeA on asexual conidiation and sclerotia formation. Conclusions 1 Volatile profiling provides a rapid, effective, and powerful approach to identify changes in intracellular metabolic networks in filamentous fungi. 2 VeA coordinates the

  13. Hybrid thermionic-photovoltaic converter

    Datas, A.

    2016-04-01

    A conceptual device for the direct conversion of heat into electricity is presented. This concept hybridizes thermionic (TI) and thermophotovoltaic (TPV) energy conversion in a single thermionic-photovoltaic (TIPV) solid-state device. This device transforms into electricity both the electron and photon fluxes emitted by an incandescent surface. This letter presents an idealized analysis of this device in order to determine its theoretical potential. According to this analysis, the key advantage of this converter, with respect to either TPV or TI, is the higher power density in an extended temperature range. For low temperatures, TIPV performs like TPV due to the negligible electron flux. On the contrary, for high temperatures, TIPV performs like TI due to the great enhancement of the electron flux, which overshadows the photon flux contribution. At the intermediate temperatures, ˜1650 K in the case of this particular study, I show that the power density potential of TIPV converter is twice as great as that of TPV and TI. The greatest impact concerns applications in which the temperature varies in a relatively wide range, for which averaged power density enhancement above 500% is attainable.

  14. Changes in humic acid conformation during coagulation with ferric chloride: implications for drinking water treatment.

    Siéliéchi, J-M; Lartiges, B S; Kayem, G J; Hupont, S; Frochot, C; Thieme, J; Ghanbaja, J; d'Espinose de la Caillerie, J B; Barrès, O; Kamga, R; Levitz, P; Michot, L J

    2008-04-01

    Electrophoretic mobility, pyrene fluorescence, surface tension measurements, transmission electron microscopy on resin-embedded samples, and X-ray microscopy (XRM) were combined to characterize the aggregates formed from humic colloids and hydrolyzed-Fe species under various conditions of pH and mixing. We show that, at low coagulant concentration, the anionic humic network is reorganized upon association with cationic coagulant species to yield more compact structures. In particular, spheroids about 80nm in size are evidenced by XRM at pH 6 and 8 just below the optimal coagulant concentration. Such reorganization of humic colloids does not yield surface-active species, and maintains negative functional groups on the outside of humic/hydrolyzed-Fe complex. We also observe that the humic network remains unaffected by the association with coagulant species up to the restabilization concentration. Upon increasing the coagulant concentration, restructuration becomes limited: indeed, the aggregation of humic acid with hydrolyzed-Fe species can be ascribed to a competition between humic network reconformation rate and collision rate of destabilized colloids. A decrease in stirring favors the shrinkage of humic/hydrolyzed-Fe complexes, which then yields a lower sediment volume. Elemental analyses also reveal that the iron coagulant species are poorly hydrolyzed in the destabilization range. This suggests that destabilization mechanisms such as sweep flocculation or adsorption onto a hydroxyde precipitate are not relevant to our case. A neutralization/complexation destabilization mechanism accompanied by a restructuration of flexible humic network is then proposed to occur in the range of pHs investigated. PMID:18155268

  15. Understory vegetation leads to changes in soil acidity and in microbial communities 27 years after reforestation.

    Fu, Xiaoli; Yang, Fengting; Wang, Jianlei; Di, Yuebao; Dai, Xiaoqin; Zhang, Xinyu; Wang, Huimin

    2015-01-01

    Experiments with potted plants and removed understories have indicated that understory vegetation often affects the chemical and microbial properties of soil. In this study, we examined the mechanism and extent of the influence of understory vegetation on the chemical and microbial properties of soil in plantation forests. The relationships between the vegetational structure (diversity for different functional layers, aboveground biomass of understory vegetation, and species number) and soil properties (pH, microbial community structure, and levels of soil organic carbon, total nitrogen, and inorganic nitrogen) were analyzed across six reforestation types (three pure needleleaf forests, a needle-broadleaf mixed forest, a broadleaf forest, and a shrubland). Twenty-seven years after reforestation, soil pH significantly decreased by an average of 0.95 across reforestation types. Soil pH was positively correlated with the aboveground biomass of the understory. The levels of total, bacterial, and fungal phospholipid fatty acids, and the fungal:bacterial ratios were similar in the shrubland and the broadleaf forest. Both the aboveground biomass of the understory and the diversity of the tree layer positively influenced the fungal:bacterial ratio. Improving the aboveground biomass of the understory could alleviate soil acidification. An increase in the aboveground biomass of the understory, rather than in understory diversity, enhanced the functional traits of the soil microbial communities. The replacement of pure plantations with mixed-species stands, as well as the enhancement of understory recruitment, can improve the ecological functions of a plantation, as measured by the alleviation of soil acidification and increased fungal dominance. PMID:25261818

  16. Tetrad effect in free energy changes of mixed ligand lanthanide-phenanthrdine-amino acid complexes

    The presence of tetrad effect has been investigated in the free energy changes accompanying the formation of lanthanide(III) mixed ligand complexes of the type [Ln(III). phen. L], where Ln(III)=La3+, Ce3+, Pr3+, Nd3+. Sm3+, Eu3+, Gd3+, Tb3+, Dy3+ or Er3+; phen= o-phenanthroline; L=histidine, β-phenyl alanine or tryptophan. The free energy changes Δ Gsub(MAL)sup(MA) have been computed from the formation constants log Ksub(MAL)sup(MA) determined pH-metrically by using, the Irving-Rossotti approach at 25degC and at ionic strength, I=0.2(mol dm-3, KNO3). The presence of tetrad effect has been demonstrated by Δ Gsub(MAL)sup(MA) vs 4fsup(n) plots, straight line approximation method, differential plot method and inclined W systematics. The magnitude of the effect has been found to lie in the sequence 4f7>4f3 - 4f4 ∼ 4f10 which constitutes an experimental evidence in favour of inter-electronic repulsion theory of tetrad effect. (author). 23 refs., 4 figs

  17. Changes in concentration of glycogen, pyruvic acid and lactic acid in the rat diaphragm under the influence of whole-body gamma irradiation

    The influence of irradiation on the concentration of glycogen, pyruvic acid and lactic acid in the diaphragm muscle were studied in rats exposed to 400 rad and 800 rad whole body gamma radiation. The results showed that the concentration of pyruvic acid and lactic acid significantly increased on the third up to the ninth day of post exposure to 400 rad whole body gamma radiation. In animals exposed to 800 rad, the diaphragm glycogen and lactic acid concentration significantly increased on the third up to the ninth day of post-exposure, while the level of pyruvic acid significantly increased on the first up to the ninth day of post-exposure as compared to the control group

  18. Growth inhibitory effect of polyunsaturated fatty acids (PUFAs on colon cancer cells via their growth inhibitory metabolites and fatty acid composition changes.

    Chengcheng Zhang

    Full Text Available Colorectal cancer is common. Polyunsaturated fatty acids (PUFAs exert growth-inhibitory and pro-apoptotic effects on colon cancer cells. Metabolites of PUFAs such as prostaglandins (PGs, leukotrienes (LTs and lipoxins (LXs play a significant role in colon cancer.Human colon cancer LoVo and RKO cells were cultured with different concentration of PUFAs and 5-fluorouracil (5-FU in vitro. Cell morphological changes, fatty acid composition, formation of PGE2, LTB4 and LXA4 and expression of COX-2, ALOX5, PGD synthase (PGDS, microsomal prostaglandin E synthase (mPGES were assessed in LoVo and RKO cells when supplemented with PUFAs and 5-FU.PUFAs and 5-FU inhibited growth of LoVo and RKO cells to the same extent at the doses used and produced significant alterations in their shape. As expected, higher concentrations of supplemented PUFAs were noted in the cells compared to control. LA, GLA, AA, ALA and EPA supplementation to LoVo cells suppressed production of PGE2, LTB4,and ALOX5, mPGES expression, but enhanced that of LXA4; whereas DHA enhanced PGE2 and LXA4 synthesis but decreased LTB4 formation and COX-2, ALOX5, mPGES expression. In contrast, 5-FU enhanced formation of PGE2, LTB4 and mPGES expression, but suppressed LXA4 synthesis and COX-2 expression. PGE2, LTB4 synthesis and ALOX5 expression was suppressed by LA, GLA, ALA and DHA; whereas AA, EPA and 5-FU enhanced PGE2 but paradoxically AA decreased and EPA and 5-FU enhanced LTB4 synthesis in RKO cells. All the PUFAs tested enhanced, while 5-FU decreased LXA4 formation in RKO cells; whereas GLA, AA, and 5-FU augmented while LA, ALA, EPA and DHA enhanced COX-2 expression in RKO cells.Tumoricidal action of PUFAs on colorectal LoVo and RKO cancer cells in vitro was associated with increased formation of LXA4, decreased synthesis of PGE2 and LTB4 and suppressed expression of COX-2, ALOX5, mPGES, whereas 5-FU produced contrasting actions on these indices.

  19. Differential response of archaeal groups to land use change in an acidic red soil.

    Shen, Ju-Pei; Cao, Peng; Hu, Hang-Wei; He, Ji-Zheng

    2013-09-01

    Land use management, one of the most important aspects of anthropogenic disturbance to terrestrial ecosystems, has exerted overriding impacts on soil biogeochemical cycling and inhabitant microorganisms. However, the knowledge concerning response of different archaeal groups to long-term land use changes is still limited in terrestrial environments. Here we used quantitative polymerase chain reaction (qPCR) and denaturing gradient gel electrophoresis (DGGE) approaches to investigate the response of archaeal communities to four different land use practices, i.e. cropland, pine forest, restoration land and degradation land. qPCR analyses showed that expression of the archaeal amoA gene responds more sensitively to changes of land use. In particular, we observed, occurring at significantly lower numbers of archaeal amoA genes in degradation land samples, while the abundance of total archaea and Group 1.1c based on 16S rRNA gene copy numbers remained constant among the different treatments examined. Soil nitrate content is significantly correlated with archaeal amoA gene abundance, but not their bacterial counterparts. The percentage of archaea among total prokaryote communities increases with increasing depth, but has no significant relationship with total carbon, total nitrogen or pH. Soil pH was significantly correlated with total bacterial abundance. Based on results from PCR-DGGE, three land use practices (i.e. cropland, pine forest, restoration land) showed distinct dominant bands, which were mostly affiliated with Group 1.1a. Degradation land, however, was dominated by sequences belonging to Group 1.1c. Results from this study suggest that community structure of ammonia oxidizing archaea were significantly impacted by land use practices. PMID:23774250

  20. Hydrothermal synthesis of hexagonal-phase NaYF4: Er, Yb with different shapes for application as photovoltaic up-converters

    Wang Dong-Feng; Zhang Xiao-Dan; Liu Yong-Juan; Wu Chun-Ya; Zhang Cun-Shan; Wei Chang-Chun; Zhao Ying

    2013-01-01

    Hexagonalβ-NaYF4 co-doped with Yb3+ and Er3+ is directly synthesized under mild conditions using a hydrothermal method.The variation of the ratio of Ln3+ to F and ethylenediaminetetraacetic acid (EDTA) causes the shape of the microcrystal to change from microplate to microcolumn.The NaYF4 powder is mixed with polydimethylsiloxane (PDMS)to create an up-converter for thin film amorphous silicon solar cells so as to evaluate the effectiveness of the synthesized material as an up-converter.In order to overcome the difficulty in measuring the effectiveness of up-conversion material,a new method of using near infrared illumination to measure the short circuit current densities of solar cells both with and without up-converters is developed.An up-converter with pure hexagonal NaYF4:yb3+/Er3+ microcrystal produces a high current output.Emission intensity data obtained by photoluminescence suggest that pure hexagonal NaYF4:yb3+/Er3+ microcrystals are more efficient than nanocrystals when used as up-converting phosphors.

  1. Hydrothermal synthesis of hexagonal-phase NaYF4: Er, Yb with different shapes for application as photovoltaic up-converters

    Hexagonal β-NaYF4 co-doped with Yb3+ and Er3+ is directly synthesized under mild conditions using a hydrothermal method. The variation of the ratio of Ln3+ to F− and ethylenediaminetetraacetic acid (EDTA) causes the shape of the microcrystal to change from microplate to microcolumn. The NaYF4 powder is mixed with polydimethylsiloxane (PDMS) to create an up-converter for thin film amorphous silicon solar cells so as to evaluate the effectiveness of the synthesized material as an up-converter. In order to overcome the difficulty in measuring the effectiveness of up-conversion material, a new method of using near infrared illumination to measure the short circuit current densities of solar cells both with and without up-converters is developed. An up-converter with pure hexagonal NaYF4:Yb3+/Er3+ microcrystal produces a high current output. Emission intensity data obtained by photoluminescence suggest that pure hexagonal NaYF4:Yb3+/Er3+ microcrystals are more efficient than nanocrystals when used as up-converting phosphors. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  2. Reactive Power Compensation using a Matrix Converter

    Holtsmark, Nathalie Marie-Anna

    2010-01-01

    This Master's thesis investigates a new application for the matrix converter: Shunt reactive power compensation. The suggested Matrix Converter-based Reactive power Compensation (MCRC) device is composed of a matrix converter, which input is connected to the grid and an electric machine at the output of the converter. The reactive power flowing in or out of the grid can be regulated with the matrix converter by controlling the magnitude and/or phase angle of the current at the input of the co...

  3. Valuing Convertible Bonds Based on LSRQM Method

    Jian Liu

    2014-01-01

    Full Text Available Convertible bonds are one of the essential financial products for corporate finance, while the pricing theory is the key problem to the theoretical research of convertible bonds. This paper demonstrates how to price convertible bonds with call and put provisions using Least-Squares Randomized Quasi-Monte Carlo (LSRQM method. We consider the financial market with stochastic interest rates and credit risk and present a detailed description on calculating steps of convertible bonds value. The empirical results show that the model fits well the market prices of convertible bonds in China’s market and the LSRQM method is effective.

  4. Analysis Of Single Phase Matrix Converter

    Divya Ahirrao

    2014-03-01

    Full Text Available This paper presents concept of single phase matrix converter. Single phase matrix converter (SPMC performs a function such as frequency changer, rectifier, inverter; chopper. This reduces the need for new converter hardware. Pulse width modulation (SPWM techniques are used to calculate the switch duty ratio to synthesis the output. The simulation of converter is carried out in MATLAB/SIMULINK. Hardware design is obtained using readily available IC‟s and other components. This paper discusses the new multiple converter for single phase input using matrix topology using just a single control logic.

  5. Changes in liquid clearance of alveolar epithelium after oleic acid-induced acute lung injury in rats

    陶军; 杨天德; 陈祥瑞; 黄河

    2004-01-01

    Objective:Impaired active fluid transport of alveolar epithelium may involve in the pathogenesis and resolution of alveolar edema. Thc objective of this study was to explore the changes in alveolar epithelial liquid clearance during lung edema following acute lung injury induced by oleic acid. Methods:Forty-eight Wistar rats were randomly divided into six groups, I.e. , injured, amiloride, ouabain, amiloride plus ouabain and terbutaline groups. Twenty- four hours after the induction of acute lung injury by intravenous oleic acid (0.25 ml/kg), 5% albumin solution with 1.5 μCi 125Ⅰ-labeled albumin (5 ml/kg) was delivered into both lungs via trachea. Alveolar liquid clearance (ALC), extravascular lung water ( EVLW ) content and arterial blood gases were measured one hour thereafter.Results: At 24 h after the infusion of oleic acid, the rats developed pulmonary edema and severe hypoxemia, with EVLW increased by 47.9% and ALC decreased by 49.2%. Addition of either 2 × 10-3 M amiloride or 5 × 10-4 M ouabain to the instillation further reduced ALC and increased EVLW. ALC increased by approximately 63.7% and EVLW decreased by 46.9% with improved hypoxemia in the Terbutaline (10-4 M) group, compared those in injured rats. A significant negative correlation was found between the increment of EVLW and the reduction of ALC. Onclusions:Active fluid transport of alveolar epithelium might play a role in the pathogenesis of lung edema in acute lung injury.

  6. Impact of temperature, pH, and salinity changes on the physico-chemical properties of model naphthenic acids.

    Celsie, Alena; Parnis, J Mark; Mackay, Donald

    2016-03-01

    The effects of temperature, pH, and salinity change on naphthenic acids (NAs) present in oil-sands process wastewater were modeled for 55 representative NAs. COSMO-RS was used to estimate octanol-water (KOW) and octanol-air (KOA) partition ratios and Henry's law constants (H). Validation with experimental carboxylic acid data yielded log KOW and log H RMS errors of 0.45 and 0.55 respectively. Calculations of log KOW, (or log D, for pH-dependence), log KOA and log H (or log HD, for pH-dependence) were made for model NAs between -20 °C and 40 °C, pH between 0 and 14, and salinity between 0 and 3 g NaCl L(-1). Temperature increase by 60 °C resulted in 3-5 log unit increase in H and a similar magnitude decrease in KOA. pH increase above the NA pKa resulted in a dramatic decrease in both log D and log HD. Salinity increase over the 0-3 g NaCl L(-1) range resulted in a 0.3 log unit increase on average for KOW and H values. Log KOW values of the sodium salt and anion of the conjugate base were also estimated to examine their potential for contribution to the overall partitioning of NAs. Sodium salts and anions of naphthenic acids are predicted to have on average 4 log units and 6 log units lower log KOW values, respectively, with respect to the corresponding neutral NA. Partitioning properties are profoundly influenced by the by the relative prevailing pH and the substance's pKa at the relevant temperature. PMID:26706930

  7. Conformational changes in human serum albumin studied by fluorescence and absorption spectroscopy. Distance measurements as a function of pH and fatty acids

    Honoré, B; Pedersen, A O

    1989-01-01

    pH- and fatty acid-induced conformational changes in human serum albumin were investigated by fluorescence-energy transfer, determining the distance between Trp-214 and bound bilirubin at 25 degrees C. This distance changes significantly with the pH, being 2.52 +/- 0.01 nm at pH 6, 2.31 +/- 0.04 ...

  8. Roasting-induced phase change and its influence on phosphorus removal through acid leaching for high-phosphorus iron ore

    Yang, Min; Zhu, Qing-shan; Fan, Chuan-lin; Xie, Zhao-hui; Li, Hong-zhong

    2015-04-01

    In the present study, roasting-induced phase change and its influence on phosphorus removal via leaching has been investigated for high-phosphorus iron ore. The findings indicate that phosphorus in the ore is associated with goethite and exists mainly in amorphous Fe3PO7 phase. The phosphorus remains in the amorphous phase after being roasted below 300°C. Grattarolaite (Fe3PO7) is found in samples roasted at 600-700°C, revealing that phosphorus phase is transformed from the amorphous form to crystalline grattarolaite during roasting. Leaching tests on synthesized pure grattarolaite reveal a low rate of phosphorus removal by sulfuric acid leaching. When the roasting temperature is higher than 800°C, grattarolaite is found to react with alumina to form aluminum phosphate, and the reactivity of grattarolaite with alumina increases with increasing roasting temperature. Consequently, the rate of phosphorus removal also increases with increasing roasting temperature due to the formation of acid-soluble aluminum phosphate.

  9. Dynamic changes in nicotinamide pyridine dinucleotide content in normal human epidermal keratinocytes and their effect on retinoic acid biosynthesis

    The function of many enzymes that regulate metabolism and transcription depends critically on the nicotinamide pyridine dinucleotides. To understand the role of NAD(P)(H) in physiology and pathophysiology, it is imperative to estimate both their amount and ratios in a given cell type. In human epidermis and in cultured epidermal keratinocytes, we found that the total dinucleotide content is in the low millimolar range. The dinucleotide pattern changes during proliferation and maturation of keratinocytes in culture. Differences in the concentrations of NAD(P)(H) of 1.5- to 12-fold were observed. This resulted in alteration of the NAD(P)H/NAD(P) ratio, which could impact the differential regulation of both transcriptional and metabolic processes. In support of this notion, we provide evidence that the two-step oxidation of retinol to retinoic acid, a nuclear hormone critical for epidermal homeostasis, can be regulated by the relative physiological amounts of the pyridine dinucleotides

  10. Modulation in radiation-induced changes in peroxidase activity with gibberellic acid in seedling's growth in chickpea (Cicer arietinum L.)

    Changes in the effects of gamma irradiation (10 to 110 Kr) with gibberellic acid (GA/sub 3/) for peroxidase activity, in relation to early days of seedling's growth in Kabulic chickpea cultivar, Noor-91, were evaluated. Stimulation in peroxidase activity over control was recorded at all the irradiation treatments from 3rd to 8th day of seedling's development. Increase in peroxidase activity at 10 and 20 Kr was due to the increase in metabolic activity, while higher doses of gamma radiation account for the damaging action and production of peroxy radicals. However, stimulation in fresh weight was observed only at 10 Kr of gamma irradiation. Postmutagenic application of Ga/sub 3/ protect the seedlings from radiation injury, by increasing the peroxides activity, and increased the fresh weight of chickpea seedlings. (author)

  11. Changes in the surface of bone and acid-etched and sandblasted implants following implantation and removal

    Eroglu, Cennet Neslihan; Ertugrul, Abdullah Seckin; Eskitascioglu, Murat; Eskitascioglu, Gurcan

    2016-01-01

    Objective: The aim of this study was to determine whether there are any changes in the surface of bone or implant structures following the removal of a screwed dental implant. Materials and Methods: For this, six individual samples of acid-etched and sandblasted implants from three different manufacturers’ implant systems were used. They were screwed in a D1 bovine bone, and they were removed after primary stabilization. The bone and implant surfaces are evaluated with scanning electron microscope. Results: Through examination of the surfaces of the bone prior to implantation and of the used and unused implant surfaces, it was found that inhomogeneity in the implant surface can cause microcracking in the bone. Conclusions: This is attributed to the stress induced during the implantation of self-tapping implants and suggests that a tap drill may be required in some instances to protect the implant surface. PMID:27011744

  12. Micro method for determination of nonesterified fatty acid in whole blood obtained by fingertip puncture

    Hansen, Jesper Søndergaard; Munk, Jens; Gaster, Michael;

    2006-01-01

    background fluorescence reading, NEFAs were converted to acyl-CoA by the acyl-CoA synthetase and the NEFA content was calculated from fluorescence emission changes using palmitic acid as external standard. The FACI-50 NEFA method was compared with two commercially available methods for quantification of NEFA....

  13. Preparation, characterization and thermal properties of styrene maleic anhydride copolymer (SMA)/fatty acid composites as form stable phase change materials

    Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA) and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the major drawback of them, limiting their utility area in thermal energy storage. The use of fatty acids as form stable PCMs will increase their feasibilities in practical applications due to the reduced cost of the LHTES system. In this regard, a series of styrene maleic anhydride copolymer (SMA)/fatty acid composites, SMA/SA, SMA/PA, SMA/MA, and SMA/LA, were prepared as form stable PCMs by encapsulation of fatty acids into the SMA, which acts as a supporting material. The encapsulation ratio of fatty acids was as much as 85 wt.% and no leakage of fatty acid was observed even when the temperature of the form stable PCM was over the melting point of the fatty acid in the composite. The prepared form stable composite PCMs were characterized using optic microscopy (OM), viscosimetry and Fourier transform infrared (FT-IR) spectroscopy methods, and the results showed that the SMA was physically and chemically compatible with the fatty acids. In addition, the thermal characteristics such as melting and freezing temperatures and latent heats of the form stable composite PCMs were measured by using the differential scanning calorimetry (DSC) technique, which indicated they had good thermal properties. On the basis of all the results, it was concluded that form stable SMA/fatty acid composite PCMs had important potential for practical LHTES applications such as under floor space heating of buildings and passive solar space heating of buildings by using wallboard, plasterboard or floors impregnated with a form stable PCM due to their satisfying thermal properties, easy preparation in desired dimensions, direct usability without needing additional encapsulation thereby eliminating the thermal resistance caused by the shell and, thus, reducing the cost of

  14. Changes of Petroleum Acid Distribution Characterized by FT-ICR MS in Heavy Acidic Crude Oil after True Boiling Point Distillation

    Liu Yingrong; Zhang Qundan; Wang Wei; Liu Zelong; Zhu Xinyi; Tian Songbai

    2014-01-01

    The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization (ESI) Fourier transform ion cyclo-tron resonance mass spectrometry (FT-ICR MS). The acid class (heteroatom number), type (z numbers) and carbon number distributions were positively characterized. It was found out that the total acid number (TAN) of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6%to 34.5%in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposed more signiifcantly because of longer heating time during the true boiling point distillation process. As a result, the reduction of TAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.

  15. Fabrication and performances of new kind microencapsulated phase change material based on stearic acid core and polycarbonate shell

    Highlights: ► Polycarbonate was utilized firstly to prepare composite phase change material. ► Microcapsules maintain original shape due to similar volume expansion coefficient. ► Latent heats of SA/PC are as high as the same type composites. ► Heat properties were studied in the domestic made set-up. - Abstract: This work is focused on the preparation, characterization and thermal properties of stearic acid/polycarbonate (SA/PC) microcapsule as a new kind of phase change material (PCM) for thermal energy storage, which was prepared by solution casting method. Its morphology, chemical structure and thermal performances were characterized by scanning electron microscope (SEM), Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC), temperature curves and volume expansion coefficient, respectively. The results show that stearic acid was encapsulated successfully with the maximum mass fraction of 52% without leakage from the composite. The average diameter of microcapsule was found to be 0.50 μm. Two components of the composite PCM, SA and PC, have no chemical reaction and exhibit good compatibility with each other. The melting and freezing temperatures and the latent heats of the microcapsule were measured as 60.0 °C and 51.2 °C, 91.4 J/g and 96.8 J/g, respectively. Iron filings were employed to improve thermal storage and release rates and the rates increased 23% compared with the composite without iron filings. Accelerated thermal cycling test showed that the microcapsules have good thermal reliability after subjected to 1000 thermal cycling because it has similar volume expansion coefficient of polycarbonate. Due to its excellent thermal stability and reliability and simple preparation method, the shape-stabilized SA/PC microcapsule can be considered as candidate PCM for thermal energy storage applications.

  16. Efficiency of Capacitively Loaded Converters

    Andersen, Thomas; Huang, Lina; Andersen, Michael A. E.;

    2012-01-01

    introduced as a definition of efficiency. The calculated and measured efficiency curves for charging DEAP actuator, polypropylene film capacitor and X7R MLCC are provided and compared. The attention has to be paid for the voltage dependent capacitive load, like X7R MLCC, when evaluating the charging......This paper explores the characteristic of capacitance versus voltage for dielectric electro active polymer (DEAP) actuator, 2kV polypropylene film capacitor as well as 3kV X7R multi layer ceramic capacitor (MLCC) at the beginning. An energy efficiency for capacitively loaded converters is...... polypropylene film capacitor can be the equivalent capacitive load. Because of the voltage dependent characteristic, X7R MLCC cannot be used to replace the DEAP actuator. However, this type of capacitor can be used to substitute the capacitive actuator with voltage dependent property at the development phase....

  17. Changes in phenolic acids and antioxidant activity in Thai rice husk at five growth stages during grain development.

    Butsat, Sunan; Weerapreeyakul, Natthida; Siriamornpun, Sirithon

    2009-06-10

    Soluble and bound phenolic acids were isolated from Thai rice husk samples at five growth stages during grain development, and their antioxidant activities were evaluated. The results showed that ferulic acid was the major soluble phenolic acid in husk at all stages, and its concentration decreased steadily during grain development. The ratio of ferulic to p-coumaric acid was approximately 2:1 at all stages. The most abundant bound phenolic acid in all extracts was p-coumaric acid, followed by ferulic acid along with traces of syringic, vanilic, and p-hydroxybenzoic acids. Most of the antioxidant activities of soluble and bound phenolic acids in husk extracts were found at flowering stage, and there were high correlations of antioxidant activity to levels of soluble ferulic, gallic, and p-coumaric acids. PMID:19432451

  18. Trends in the wide web converting markets for UV curing

    As we prepare to enter a new decade, the use of ultraviolet (UV) energy to initiate the polymerization of coatings in the wide web segment of the Converting industry continues to increase. As is typical in the Converting industry, while many of the significant advances in technology have been developed around the world, they have been driven initially by the Western European markets. This was true with regards to the introduction of water-borne Pressure Sensitive Adhesives and thermal curing 100% solids silicone release coatings during the late 1970s and early 1980s, but this trend has changed with regards to the current state-of-the-art in UV curing

  19. A Novel FPSM Controller for DC-DC Switching Converters

    Yong Feng; Shun-Ping Wang; Ping Luo; Quan-Ming Niu; Zhao-Ji Li

    2007-01-01

    This paper presents a novel fuzzy pulse skip modulation (FPSM) controller for switching direct current to direct current (DC-DC) converters based on fuzzy ratiocination modeling approach. Owing to the optimal consideration during the design and the nonlinear characteristics of the controller, improved dynamic responses of the FPSM controller can be achieved over conventional controllers. Compared with conventional proportion integral derivative (PID) control, FPSM control has 60% lower overshoot and 10% lower setting time under the same input voltage and output load change. The presented approach is general and can be applied to other types of DC-DC converters.

  20. Basic Aspects Related to Operation of Engine Catalytic Converters

    Adam Ciesiolkiewicz

    2004-03-01

    Full Text Available Experimental research on the diesel engine 6C107 equipped with selected oxidation catalytic converters was carried out. Specific emissions of toxic substances were investigated in the whole operation range of the engine before and after catalysts. Thus, changes of the emission indices within the catalysts and conversion efficiencies of the harmful substances were evaluated. Besides, temperature threshold of the catalytic action was determined too. Apart from chemical efficiency of the converters, their resistance to exhaust gas flow also is an essential problem. Therefore selected quantities of exhaust gas flow through the catalysts were determined and analysed together with their termochemical efficiency.

  1. Fruit load induces changes in global gene expression and in abscisic acid (ABA) and indole acetic acid (IAA) homeostasis in citrus buds.

    Shalom, Liron; Samuels, Sivan; Zur, Naftali; Shlizerman, Lyudmila; Doron-Faigenboim, Adi; Blumwald, Eduardo; Sadka, Avi

    2014-07-01

    Many fruit trees undergo cycles of heavy fruit load (ON-Crop) in one year, followed by low fruit load (OFF-Crop) the following year, a phenomenon known as alternate bearing (AB). The mechanism by which fruit load affects flowering induction during the following year (return bloom) is still unclear. Although not proven, it is commonly accepted that the fruit or an organ which senses fruit presence generates an inhibitory signal that moves into the bud and inhibits apical meristem transition. Indeed, fruit removal from ON-Crop trees (de-fruiting) induces return bloom. Identification of regulatory or metabolic processes modified in the bud in association with altered fruit load might shed light on the nature of the AB signalling process. The bud transcriptome of de-fruited citrus trees was compared with those of ON- and OFF-Crop trees. Fruit removal resulted in relatively rapid changes in global gene expression, including induction of photosynthetic genes and proteins. Altered regulatory mechanisms included abscisic acid (ABA) metabolism and auxin polar transport. Genes of ABA biosynthesis were induced; however, hormone analyses showed that the ABA level was reduced in OFF-Crop buds and in buds shortly following fruit removal. Additionally, genes associated with Ca(2+)-dependent auxin polar transport were remarkably induced in buds of OFF-Crop and de-fruited trees. Hormone analyses showed that auxin levels were reduced in these buds as compared with ON-Crop buds. In view of the auxin transport autoinhibition theory, the possibility that auxin distribution plays a role in determining bud fate is discussed. PMID:24706719

  2. Seasonal Changes in Mycosporine-Like Amino Acid Production Rate with Respect to Natural Phytoplankton Species Composition

    Sun-Yong Ha

    2015-11-01

    Full Text Available After in situ incubation at the site for a year, phytoplanktons in surface water were exposed to natural light in temperate lakes (every month; thereafter, the net production rate of photoprotective compounds (mycosporine-like amino acids, MAAs was calculated using 13C labeled tracer. This is the first report describing seasonal variation in the net production rate of individual MAAs in temperate lakes using a compound-specific stable isotope method. In the mid-latitude region of the Korean Peninsula, UV radiation (UVR usually peaks from July to August. In Lake Paldang and Lake Cheongpyeong, diatoms dominated among the phytoplankton throughout the year. The relative abundance of Cyanophyceae (Anabaena spiroides reached over 80% during July in Lake Cheongpyeong. Changes in phytoplankton abundance indicate that the phytoplankton community structure is influenced by seasonal changes in the net production rate and concentration of MAAs. Notably, particulate organic matter (POM showed a remarkable change based on the UV intensity occurring during that period; this was because of the fact that cyanobacteria that are highly sensitive to UV irradiance dominated the community. POM cultured in Lake Paldang had the greatest shinorine (SH production rate during October, i.e., 83.83 ± 10.47 fgC·L−1·h−1. The dominance of diatoms indicated that they had a long-term response to UVR. Evaluation of POM cultured in Lake Cheongpyeong revealed that there was an increase in the net MAA production in July (when UVR reached the maximum; a substantial amount of SH, i.e., 17.62 ± 18.34 fgC·L−1·h−1, was recorded during this period. Our results demonstrate that both the net production rate as well as the concentration of MAAs related to photoinduction depended on the phytoplankton community structure. In addition, seasonal changes in UVR also influenced the quantity and production of MAAs in phytoplanktons (especially Cyanophyceae.

  3. [Studies on changes in nucleolar organizer region of human promyelocytic leukemia cells (HL-60) treated with retinoic acid].

    Xie, R L; Wang, Y Q

    1989-12-01

    Changes of nucleolar organizer region in HL-60 cells after treated with retinoic acid (RA) were studied with techniques of silver-staining nucleolar organizer region (Ag-NOR) in metaphase karyotypes, Brachet's reaction and with our improved TEM techniques for studying silver-stained active nucleolar organizer region (Ag-aNOR) in interphase nucleoli. Number of Ag-NOR in HL-60 cells is 4.5/cell on average. The Ag-NOR number of cells treated with RA showed no remarkable difference from that of control group. Ag-aNOR number treated with RA was reduced obviously as compared with that of control group. Meanwhile, the changes of nucleolus number showed by Brachet's reaction were in accordance with those of Ag-aNOR. Therefore, it may be concluded: (1). Though the number of active rRNA genes did not changed after the differentiation of HL-60 cells induced by RA, their expression was clearly inhibited: (2). The relationship between the changes of Brachet-No and Ag-aNOR is in positive correlation (r = 0.98, p less than 0.01). EM examination of Ag-aNOR of HL-60 cells reveals that Ag-protein (RNA polymerase I) only presented in fibrillar centers (FC) and the dense fibrillar components (DFC) of nucleolus. In addition, in control group, large amount of Ag-protein, FC, DFC and granular components (GC) were observed, and there were many large nucleoli in a nucleus, meanwhile, the cells of the treated group tended to be mature, with a decrease in the amount of Ag-protein, FC, DFC and GC accordingly, and the nucleoli reduced both in size and number significantly.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2626898

  4. Changes in uric acid levels following bariatric surgery are not associated with SLC2A9 variants in the Swedish Obese Subjects Study.

    Mark A Sarzynski

    Full Text Available CONTEXT AND OBJECTIVE: Obesity and SLC2A9 genotype are strong determinants of uric acid levels. However, data on SLC2A9 variants and weight loss induced changes in uric acid levels are missing. We examined whether the changes in uric acid levels two- and ten-years after weight loss induced by bariatric surgery were associated with SLC2A9 single nucleotide polymorphisms (SNPs in the Swedish Obese Subjects study. METHODS: SNPs (N = 14 identified by genome-wide association studies and exonic SNPs in the SLC2A9 gene locus were genotyped. Cross-sectional associations were tested before (N = 1806, two (N = 1664 and ten years (N = 1201 after bariatric surgery. Changes in uric acid were compared between baseline and Year 2 (N = 1660 and years 2 and 10 (N = 1172. A multiple testing corrected threshold of P = 0.007 was used for statistical significance. RESULTS: Overall, 11 of the 14 tested SLC2A9 SNPs were significantly associated with cross-sectional uric acid levels at all three time points, with rs13113918 showing the strongest association at each time point (R(2 = 3.7-5.2%, 3.9×10(-22≤p≤7.7×10(-11. One SNP (rs737267 showed a significant association (R(2 = 0.60%, P = 0.002 with change in uric acid levels from baseline to Year 2, as common allele homozygotes (C/C, N = 957 showed a larger decrease in uric acid (-61.4 µmol/L compared to minor allele carriers (A/X: -51.7 µmol/L, N = 702. No SNPs were associated with changes in uric acid from years 2 to 10. CONCLUSIONS: SNPs in the SLC2A9 locus contribute significantly to uric acid levels in obese individuals, and the associations persist even after considerable weight loss due to bariatric surgery. However, we found little evidence for an interaction between genotype and weight change on the response of uric acid to bariatric surgery over ten years. Thus, the fluctuations in uric acid levels among the surgery group appear to be driven by the weight

  5. Applications and benefits of catalytic converter thermal management

    Burch, S.D.; Keyser, M.A.; Colucci, C.P.; Potter, T.F.; Benson, D.K.; Biel, J.P.

    1996-07-01

    A catalytic converter thermal management system (TMS) using variable-conductance vacuum insulation and phase-change thermal storage can maintain the converter temperature above its operating temperature for many hours, allowing most trips to begin with minimal ``cold-start`` emissions. The latest converter TMS prototype was tested on a Ford Taurus (3.0 liter flex-fuel engine) at Southwest Research Institute. Following a 24-hour soak, the FTP-75 emissions were 0.031, 0.13, and 0.066 g/mile for NMHC, CO, and NOx, respectively. Tests were also run using 85% ethanol (E85), resulting in values of 0.005, 0.124, and 0.044 g/mile, and 0.005 g/mile NMOG. Compared to the baseline FTP levels, these values represent reductions of 84% to 96% for NMHC, NMOG, and CO.

  6. On the dynamics of a novel ocean wave energy converter

    Orazov, B.

    2010-11-01

    Buoy-type ocean wave energy converters are designed to exhibit resonant responses when subject to excitation by ocean waves. A novel excitation scheme is proposed which has the potential to improve the energy harvesting capabilities of these converters. The scheme uses the incident waves to modulate the mass of the device in a manner which amplifies its resonant response. To illustrate the novel excitation scheme, a simple one-degree of freedom model is developed for the wave energy converter. This model has the form of a switched linear system. After the stability regime of this system has been established, the model is then used to show that the excitation scheme improves the power harvesting capabilities by 2565 percent even when amplitude restrictions are present. It is also demonstrated that the sensitivity of the device\\'s power harvesting capabilities to changes in damping becomes much smaller when the novel excitation scheme is used. © 2010 Elsevier Ltd. All rights reserved.

  7. Regulation of the output power at the resonant converter

    In this paper a method for regulating an alternating current voltage source with pair of IGBT transistor’s modules, in a full bridge configuration with series resonant converter is given. With the developed method a solution is obtained which can regulate the phase difference between output voltage and current through the inductor, in order to maintain maximum output power. Control electronic via feedback signals regulates the energy transfer to the tank by changing the pulse width of signals which are used as inputs to the gates of the IGBTs. By increasing or decreasing the pulse width transmitted to the various gates of the IGBT the energy transfer to the tank is increased or decreased . PowerSim simulations program is used for development of controlling methodology. Developed method is practically implemented in a prototype of the device for phase control of resonant converter with variable the resonant load. Key words: pulse width method, phase regulation , power converter

  8. Digital control of grid connected converters for distributed power generation

    Skjellnes, Tore

    2008-07-01

    Pulse width modulated converters are becoming increasingly popular as their cost decreases and power rating increases. The new trend of small scale power producers, often using renewable energy sources, has created new demands for delivery of energy to the grid. A major advantage of the pulse width modulated converter is the ability to control the output voltage at any point in the voltage period. This enables rapid response to load changes and non-linear loads. In addition it can shape the voltage in response to the output current to create an outward appearance of a source impedance. This is called a virtual impedance. This thesis presents a controller for a voltage controlled three phase pulse width modulated converter. This controller enables operation in standalone mode, in parallel with other converters in a micro grid, and in parallel with a strong main grid. A time varying virtual impedance is presented which mainly attenuates reactive currents. A method of investigating the overall impedance including the virtual impedance is presented. New net standards have been introduced, requiring the converter to operate even during severe dips in the grid voltage. Experiments are presented verifying the operation of the controller during voltage dips. (Author). 37 refs., 65 figs., 10 tabs

  9. Climate-resilient agroforestry: physiological responses to climate change and engineering of crassulacean acid metabolism (CAM) as a mitigation strategy.

    Borland, Anne M; Wullschleger, Stan D; Weston, David J; Hartwell, James; Tuskan, Gerald A; Yang, Xiaohan; Cushman, John C

    2015-09-01

    Global climate change threatens the sustainability of agriculture and agroforestry worldwide through increased heat, drought, surface evaporation and associated soil drying. Exposure of crops and forests to warmer and drier environments will increase leaf:air water vapour-pressure deficits (VPD), and will result in increased drought susceptibility and reduced productivity, not only in arid regions but also in tropical regions with seasonal dry periods. Fast-growing, short-rotation forestry (SRF) bioenergy crops such as poplar (Populus spp.) and willow (Salix spp.) are particularly susceptible to hydraulic failure following drought stress due to their isohydric nature and relatively high stomatal conductance. One approach to sustaining plant productivity is to improve water-use efficiency (WUE) by engineering crassulacean acid metabolism (CAM) into C3 crops. CAM improves WUE by shifting stomatal opening and primary CO2 uptake and fixation to the night-time when leaf:air VPD is low. CAM members of the tree genus Clusia exemplify the compatibility of CAM performance within tree species and highlight CAM as a mechanism to conserve water and maintain carbon uptake during drought conditions. The introduction of bioengineered CAM into SRF bioenergy trees is a potentially viable path to sustaining agroforestry production systems in the face of a globally changing climate. PMID:25366937

  10. In vivo measurements of changes in pH triggered by oxalic acid in leaf tissue of transgenic oilseed rape.

    Zou, Qiu-Ju; Liu, Sheng-Yi; Dong, Xu-Yan; Bi, Yan-Hua; Cao, Yuan-Cheng; Xu, Qiao; Zhao, Yuan-Di; Chen, Hong

    2007-01-01

    Oxalic acid (OA), a non-host-specific toxin secreted by Sclerotinia sclerotiorum during pathogenesis, has been demonstrated to be a major phytotoxic and pathogenic factor. Oxalate oxidase (OXO) is an enzyme associated with the detoxification of OA, and hence the introduction of an OXO gene into oilseed rape (Brassica napus L.) to break down OA may be an alternative way of increasing the resistance of the plant to Sclerotinia sclerotiorum. In order to investigate the activation of OXO in transgenic oilseed rape, a convenient and accessible method was used to monitor changes in pH in response to stress induced by OA. The pH sensor, a platinum microcylinder electrode modified using polyaniline film, exhibited a linear response within the pH range from 3 to 7, with a Nernst response slope of 70 mV/pH at room temperature. The linear correlation coefficient was 0.9979. Changes induced by OA in the pH values of leaf tissue of different oilseed rape species from Brassica napus L. were monitored in real time in vivo using this electrode. The results clearly showed that the transgenic oilseed rape was more resistant to OA than non-transgenic oilseed rape. PMID:17623369

  11. Successional changes in the chicken cecal microbiome during 42 days of growth are independent of organic acid feed additives

    Oakley, Brian B; Buhr, R Jeff; Ritz, Casey W; Kiepper, Brian H; Berrang, Mark E.; Seal, Bruce S.; Cox, Nelson A

    2014-01-01

    Background Poultry remains a major source of foodborne bacterial infections. A variety of additives with presumed anti-microbial and/or growth-promoting effects are commonly added to poultry feed during commercial grow-out, yet the effects of these additives on the gastrointestinal microbial community (the GI microbiome) as the bird matures remain largely unknown. Here we compared temporal changes in the cecal microbiome to the effects of formic acid, propionic acid, and medium-chain fatty ac...

  12. Reducing cold-start emissions by catalytic converter thermal management

    Burch, S D; Potter, T F; Keyser, M A [National Renewable Energy Lab., Golden, CO (United States); Brady, M J; Michaels, K F [Chrysler Corp. (United States)

    1995-01-01

    Vacuum insulation and phase-change thermal storage have been used to enhance the heat retention of a prototype catalytic converter. Storing heat in the converter between trips allows exhaust gases to be converted more quickly, significantly reducing cold-start emissions. Using a small metal hydride, the thermal conductance of the vacuum insulation can be varied continuously between 0.49 and 27 W/m{sup 2}K (R-12 to R-0.2 insulation) to prevent overheating of the catalyst. A prototype was installed in a Dodge Neon with a 2.0-liter engine. Following a standard preconditioning and a 23-hour cold soak, an FTP (Federal Test Procedure) emissions test was performed. Although exhaust temperatures during the preconditioning were not hot enough to melt the phase-change material, the vacuum insulation performed well, resulting in a converter temperature of 146{degrees}C after the 23-hour cold soak at 27{degrees}C. Compared to the same converter at ambient conditions, overall emissions of CO and HC were reduced by 52 % and 29 %, to 0.27 and 0.037 g/mile, respectively. The maximum converter temperature during the FTP cycle was 720{degrees}C. This limited testing was performed with a nearly-fresh palladium-only catalyst, but demonstrates the potential of this vacuum insulation approach for emissions reduction and thermal control. Further testing is ongoing. An initial assessment of several production issues is made, including high-volume fabrication challenges, durability, and cost.

  13. Changes in total protein and amino acids content of the onion bulb fly, Eumerus Amoenus loew (Diptera: Syrphidae) Sterilized with gamma radiation

    The present work was carried out on the onion bulb fly, Eumerus Amoenus to study the changes which occurred in the components of the sterilized adults, especially the total protein content and amino acid composition. The total protein content in males was more than in females and decreased in sterilized males. An increase from 170.8 in the control to 177.5, 214.3 and 207.7 mg/g body weight was noted in sterilized females. The amino acid contents of the sterilized flies was greatly affected, the effect was obvious in alanine, glycine and glutamic acid. 2 tabs

  14. The Micro-Changes of Fly Ash in the Utilization of “Dip in One Acid Twice/Unite Two Kinds of Alkalis”

    DENG, Yinsheng; Xu, Sujuan; Xu, Jiangtao; Liu, Shaohui

    2010-01-01

    Determined the new technology of element leaching in fly ash’s utilization---- “dip in one acid twice/unite two kinds of alkalis” through comparison tests, the technique consist of four phases: acid leaching、alkali dissolution, calcination and second acid leaching, the maximum fine utilization rates of silicon, aluminum, iron are respectively 97.07%, 86.67%, 96.54%, the total utilization rate is 100%. Analyzed the micro-changes of fly ash in the utilization process by X-ray diffraction and sc...

  15. Morphological and serum hyaluronic acid, laminin and type Ⅳ collagen changes in dimethylnitrosamine-induced hepatic fibrosis of rats

    Chun-Hui Li; Dong-Ming Piao; Wen-Xie Xu; Zheng-Ri Yin; Jing-Shun Jin; Zhe-Shi Shen

    2005-01-01

    AIM: To study the morphological and serum hyaluronic acid (HA), laminin (LN), and type Ⅳ collagen changes in hepatic fibrosis of rats induced by dimethylnitrosamine (DMN).METHODS: The rat model of liver fibrosis was induced by DMN. Serum HA, type Ⅳ collagen, and LN were measured by ELISA. The liver/weight index and morphological changes were examined under electron microscope on d 7, 14, 21, and 28 by immunohistochemical alpha smooth muscle actin α-SMA staining as well as Sirius-red and HE staining.RESUJLTS: The levels of serum HA, type Ⅳ collagen and LN significantly increased from d 7 to d 28 (P = 0.043).The liver/weight index increased on d 7 and decreased on d 28. In the model group, the rat liver stained with HE and Sirius-red showed evident hemorrhage and necrosis in the central vein of hepatic 10 lobules on d 7. Thin fibrotic septa were formed joining central areas of the liver on d 14. The number of α-SMA positive cells was markedly increased in the model group. Transitional hepatic stellate cells were observed under electron microscope.All rats in the model group showed micronodular fibrosis in the hepatic parenchyma and a network of α-SMA positive cells. Typical myofibroblasts were embedded in the core of a fibrous septum. Compared to the control group, the area-density percentage of collagen fibrosis and pathologic grading were significantly different in the model group (P<0.05) on different d (7, 14, and 28). The area-density percentage of collagen fibrosis in hepatic tissue had a positive correlation with the levels of serum HA, LN, and type Ⅳ collagen.CONCLUSION: The morphological and serum HA, type Ⅳ collagen, and LN are changed in DMN-induced liver fibrosis in rats.

  16. Converting Relational Database Into Xml Document

    Kanagaraj.S

    2012-03-01

    Full Text Available XML (Extensible Markup Language is emerging and gradually accepted as the standard for data interchange in the Internet world. Interoperation of relational database and XML database involves schema and data translations. Through EER (extended entity relationship model can convert the schema of relational database into XML. The semantics of the relational database, captured in EER diagram, are mapped to XML schema using stepwise procedures and mapped to XML document under the definitions of the XML schema. Converting Relational Database into XML Document is a process of converting the existing databases into XML file format. Existing conversion techniques convert a single database into xml. The proposed approach performs the conversion of databases like Ms-Access, MS-SQL to XML file format. Read the tables information from the corresponding database and generate code for the appropriate databases and convert the tables into XML flat file format. This converted XML file is been presented to the user.

  17. Radiation-Tolerant DC-DC Converters

    Skutt, Glenn; Sable, Dan; Leslie, Leonard; Graham, Shawn

    2012-01-01

    A document discusses power converters suitable for space use that meet the DSCC MIL-PRF-38534 Appendix G radiation hardness level P classification. A method for qualifying commercially produced electronic parts for DC-DC converters per the Defense Supply Center Columbus (DSCC) radiation hardened assurance requirements was developed. Development and compliance testing of standard hybrid converters suitable for space use were completed for missions with total dose radiation requirements of up to 30 kRad. This innovation provides the same overall performance as standard hybrid converters, but includes assurance of radiation- tolerant design through components and design compliance testing. This availability of design-certified radiation-tolerant converters can significantly reduce total cost and delivery time for power converters for space applications that fit the appropriate DSCC classification (30 kRad).

  18. Multilevel converters for 10 MW Wind Turbines

    Ma, Ke; Blaabjerg, Frede

    2011-01-01

    Several promising multi-level converter configurations for 10 MW Wind Turbines both with direct drive and one-stage gear box drive using Permanent Magnet Synchronous Generator (PMSG) are proposed, designed and compared. Reliability is a crucial indicator for large scale wind power converters......, therefore the evaluations are mainly focused on the power device thermal performances, which are closely related to the life time and cost of the converter. Simulation results of different converter candidates regarding the loss and junction temperature are presented and analyzed. It is concluded that the...... three-level and five-level H-bridge converter topologies both have potential to achieve improved thermal performances compared to the three-level Neutral-Point-Clamped converter topology in the wind power application....

  19. The effect of esmolol on corrected-QT interval, corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients taking an angiotensin-converting enzyme inhibitor

    Zahit Çeker; Suna Akin Takmaz; Bülent Baltaci; Hülya Basar

    2015-01-01

    BACKGROUND AND OBJECTIVES: The importance of minimizing the exaggerated sympatho-adrenergic responses and QT interval and QT interval dispersion changes that may develop due to laryngoscopy and tracheal intubation during anesthesia induction in the hypertensive patients is clear. Esmolol decreases the hemodynamic response to laryngoscopy and intubation. However, the effect of esmolol in decreasing the prol...

  20. Predicted Changes in Fatty Acid Intakes, Plasma Lipids, and Cardiovascular Disease Risk Following Replacement of trans Fatty Acid-Containing Soybean Oil with Application-Appropriate Alternatives

    Lefevre, Michael; Mensink, Ronald P.; Kris-Etherton, Penny M.; Petersen, Barbara; Smith, Kim; Flickinger, Brent D.

    2012-01-01

    The varied functional requirements satisfied by trans fatty acid (TFA)—containing oils constrains the selection of alternative fats and oils for use as potential replacements in specific food applications. We aimed to model the effects of replacing TFA-containing partially hydrogenated soybean oil (PHSBO) with application-appropriate alternatives on population fatty acid intakes, plasma lipids, and cardiovascular disease (CVD) risk. Using the National Health and Nutrition Examination Survey 2...

  1. Constitutive Androstane Receptor-Mediated Changes in Bile Acid Composition Contributes to Hepatoprotection from Lithocholic Acid-Induced Liver Injury in MiceS⃞

    Beilke, Lisa D.; Aleksunes, Lauren M.; Holland, Ricky D; Besselsen, David G; Beger, Rick D.; Klaassen, Curtis D.; Cherrington, Nathan J.

    2009-01-01

    Pharmacological activation of the constitutive androstane receptor (CAR) protects the liver during cholestasis. The current study evaluates how activation of CAR influences genes involved in bile acid biosynthesis as a mechanism of hepatoprotection during bile acid-induced liver injury. CAR activators phenobarbital (PB) and 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) or corn oil (CO) were administered to C57BL/6 wild-type (WT) and CAR knockout (CAR-null) mice ...

  2. Exploration of the Chaotic Behaviour in a Buck-Boost Converter Depending on the Converter and Load Elements

    Demirbaş, Şevki; Fidanboy, Hikmet; Kurt, Erol

    2016-08-01

    In this paper, detailed analyses of the chaotic behavior observed in a buck-boost converter are presented. Although this basic converter system is already known world-wide for the purpose of dc-dc conversion of the output of renewable energy systems, it indicates certain chaotic regimes where both the output amplitude and frequency change randomly. This chaotic regime can yield an unstable output over the resistive or resistive/inductive electrical loads. This study presents a detailed map for the regular and chaotic regions in terms of material parameters, such as converter capacitance C, resistive load R, and inductive load L. Thus, the stable area of operation for efficient and renewable electricity production will be ascertained for the studied converter system. We emphasize that the material parameters C, R, and L play important roles in generating energy from the solar cell; indeed, the stability increases with higher values of the converter capacitor and load inductance, whereas it decreases according to the resistive load. A number of periodic windows have been observed and the output frequency gives a broad-band spectrum of up to 50 kHz.

  3. Exploration of the Chaotic Behaviour in a Buck-Boost Converter Depending on the Converter and Load Elements

    Demirbaş, Şevki; Fidanboy, Hikmet; Kurt, Erol

    2016-03-01

    In this paper, detailed analyses of the chaotic behavior observed in a buck-boost converter are presented. Although this basic converter system is already known world-wide for the purpose of dc-dc conversion of the output of renewable energy systems, it indicates certain chaotic regimes where both the output amplitude and frequency change randomly. This chaotic regime can yield an unstable output over the resistive or resistive/inductive electrical loads. This study presents a detailed map for the regular and chaotic regions in terms of material parameters, such as converter capacitance C, resistive load R, and inductive load L. Thus, the stable area of operation for efficient and renewable electricity production will be ascertained for the studied converter system. We emphasize that the material parameters C, R, and L play important roles in generating energy from the solar cell; indeed, the stability increases with higher values of the converter capacitor and load inductance, whereas it decreases according to the resistive load. A number of periodic windows have been observed and the output frequency gives a broad-band spectrum of up to 50 kHz.

  4. Age-related changes in metabolism and disposition of salicylic acid (SAL) in male Fischer 344 rats

    SAL-induced nephrotoxicity has been reported to be greater in older rats. To examine age- and dose-related changes in disposition and metabolism, SAL was administered po at 5, 50 and 500 mg/kg to male Fischer 344 rats aged 3, 12, and 25 mo. At 5 mg 14C-SAL/kg, urinary excretion was complete by 24hr in 3 and 25 mo rats, but not until 48 hours in 12 mo rats. No age-related differences were observed in the percentage of administered 14C-SAL excreted as oxidative metabolites, unmetabolized SAL, or salicyl ester glucuronide. 25 mo rats excreted significantly less of a total dose of 14C-SAL as the ether glucuronide, while a significant age-related increase was noted in the percentage excreted as salicyluric acid (SUA). At 50 mg 14C-SAL/kg, urinary elimination shifted towards zero-order kinetics and excretion was not complete until 48 hr in all age groups. The percentage of an administered dose of 14C-SAL found in urine as oxidative metabolites and SAL ester glucuronide increased significantly in all age groups, while the percentage excreted as SUA decreased. In addition, 12 and 25 month rats excreted a significantly greater percentage of the total dose as 2,3 and 2,5-dihydroxybenzoic acid than 3 mo rats at ≥ 50 mg 14C-SAL/kg. These results indicate that increased production of oxidative metabolites in older rats at higher doses of SAL may be responsible in part for the age-related increase in acute SAL nephrotoxicity

  5. Protective role of acetylsalicylic acid (Aspirin) against gamma irradiation-induced ophthalmic and histological changes in rat's eye

    Radiation generates a variety of free radicals during the exposure of biological tissues through radiolysis of water. These free radicals are highly reactive and cause oxidative damage to biological molecules. This study examined the protective ability of aspirin against radiation-induced ophthalmic and histological disorders in the eye of rats exposed to 6.5 Gy single dose of gamma irradiation, Acetylsalicylic acid was given daily to rats in drinking water (2.5 g/ L) 1 week pre-irradiation, during irradiation and 9 weeks post-irradiation. Experimental investigations showed that irradiation caused cataract formation. Irradiation also caused histopathological changes in the retina of the eyes described as focal degeneration and necrosis of the inner and outer nuclear layers, vacuolation of ganglionic cell layer as well as necrosis of retinal inner and outer segments of the rods and cones. The cornea revealed vacuolation of stratified epithelial layer, edema in substantia propria with dispersion of the connective tissue as well as presence of extravasated red blood cells as a result of exposure to radiation. The lens became homogenous and oesinophilic due to radiation exposure. The eye tissues of rats .that received acetylsalicylic acid supplement showed slight improvement of radiation-induced histological damage in the eyes and it also delayed the onset of cataract formation. According to the results obtained it could be concluded that oral administration of aspirin gave only a slight, nonsignificant reduction of eye radiation injury after exposure to single dose of gamma irradiation (6.5 Gy). The anatomy, physiology and biochemistry of the visual system make the eye uniquely vulnerable to damage from injurious agents, physical and chemical. Although many studies were conducted on a broad range of agents, the majority of all efforts are directed at deleterious effect of radiation on the eye tissues, and

  6. 荔枝果酒加工过程中有机酸的变化研究%Changes of organic acids content during the production oflitchi wine

    刘晓艳; 白卫东; 蒋爱民; 沈颖; 潘志民

    2011-01-01

    The changes of organic acids during the production of litchi wine were studied in this paper. The results indicated that the main organic acids in litchi wine were lactic acid, malic acid, tartaric acid, acetic acid and succinic acid. The high concentration of malic acid, acetic acid, tartaric acid and succinic acid caused the bad taste of litchi wine. In the production, the concentration of malic acid, tartaric acid and succinic acid were increased by 2.27g/L~2.80g/L, 0.77g/L, 0.27g/L, respectively. The acetic acid content was decreased by 9.38g/L~9.44g/L. In order to improve the taste of litchi wine, the content and proportion of related organic acids could be adjusted by controlling the process of hydrolyzing and adjusting the component and fermentation.%该文研究了荔枝果酒在加工过程中有机酸的变化,结果表明,荔枝酒中主要的有机酸为乳酸、苹果酸、酒石酸、乙酸和琥珀酸.荔枝果酒的口感不佳,是由于苹果酸、乙酸、酒石酸及琥珀酸含量过高而引起.荔枝汁加工成荔枝酒的过程中,苹果酸、酒石酸及琥珀酸的含量分别增加2.80g/L~2.27g/L、0.77g/L和0.27g/L;乙酸含量减少9.44g/L~9.38g/L.要调整相关有机酸的含量和比例以达到改善荔枝酒口感的目的,可以通过控制酶解、调整成分及酒精发酵等工艺过程而实现.

  7. Silicon waveguide based TE mode converter.

    Zhang, Jing; Liow, Tsung-Yang; Yu, Mingbin; Lo, Guo-Qiang; Kwong, Dim-Lee

    2010-11-22

    A silicon waveguide based TE mode converter was designed for the mode conversion between a horizontal waveguide and vertical waveguide in the two-layer structure waveguide based polarization diversity circuit. The TE mode converter's performance was studied. The polarization mode converter with minimum length of 5 μm was demonstrated to provide the TE mode conversion while maintaining the polarization status. The insertion loss at the transition region was less than 2 dB. PMID:21164874

  8. Estimating the temperature of a catalytic converter

    Ma, T.T.-H.

    1994-11-02

    A method is described for estimating the temperature in a catalytic converter used in the exhaust system of an internal combustion engine. Pressure sensors monitor the flow resistance across the catalytic converter to provide an indication of the temperature inside. This feedback system allows heating devices to be switched off and thus avoid overheating, while maintaining the catalytic converter's efficiency by assuring that it does not operate below its light off temperature. (UK)

  9. Estimating the temperature of a catalytic converter

    Ma, T.T.-H.

    1994-11-02

    A method of estimating the temperature of a catalytic converter used in the exhaust system of an internal combustion engine is described. Heated exhaust gas oxygen (HEGO) sensors are placed upstream and downstream of the catalytic converter. The temperature of the catalytic converter shortly after start-up is measured by monitoring the resistance of the HEGO sensor's heating element. The downstream sensor is used for mixture control and to double check results of the upstream sensor. (UK)

  10. Timing of Convertible Debt Financing and Investment

    Kyoko Yagi; Ryuta Takashima; Hiroshi Takamori; Katsushige Sawaki

    2008-01-01

    In this paper, we examine the optimal investment policy of the firm which is financed by issuing equity, straight debt and convertible debt. We extend the model in Mauer and Sarkar (2005) over financing with convertible debt. We examine two different investment policies that maximize the equity value and the firm value and show the agency cost as the difference between each policy value. Furthermore, we investigate how the issuance of convertible debt affects investment.

  11. Efficient Implementation of Sample Rate Converter

    Charanjit singh; Manjeet Singh patterh; Sanjay Sharma

    2011-01-01

    Within wireless base station system design, manufacturers continue to seek ways to add value and performance while increasing differentiation. Transmit/receive functionality has become an area of focus as designers attempt to address the need to move data from very high frequency sample rates to chip processing rates. Digital Up Converter (DUC) and Digital Down Converter (DDC) are used as sample rate converters. These are the important block in every digital communication system; hence there ...

  12. Regeneration of ZVS converter with Resonant inductor

    J.Sivavara Prasad

    2011-09-01

    Full Text Available This paper presents an analysis of the regeneration of zero-voltage-switching converter with resonant inductor, quasi-resonant converters, and full-bridge zero-voltage-switched PWM Converter. The design of a clamping circuit considering a saturable resonant inductor is presented and compared with the design of a clamping circuit with a linear resonant inductor. A diode model with reverse recovery is employed to simulate the effects.

  13. Changes in stream chemistry and biology in response to reduced levels of acid deposition during 1987-2003 in the Neversink River Basin, Catskill Mountains

    Burns, Douglas A.; Riva-Murray, K.; Bode, R.W.; Passy, S.

    2008-01-01

    Atmospheric acid deposition has decreased in the northeastern United States since the 1970s, resulting in modest increases in pH, acid-neutralizing capacity (ANC), and decreases in inorganic monomeric aluminum (AlIM) concentrations since stream chemistry monitoring began in the 1980s in the acid-sensitive upper Neversink River basin in the Catskill Mountains of New York. Stream pH has increased by 0.01 units/year during 1987-2003 at three sites in the Neversink basin as determined by Seasonal Kendall trend analysis. In light of this observed decrease in stream acidity, we sampled 12 stream sites within the Neversink River watershed for water chemistry, macroinvertebrates, fish, and periphytic diatoms in 2003 to compare with a similar data set collected in 1987. Metrics and indices that reflect sensitivity to stream acidity were developed with these biological data to determine whether changes in stream biota over the intervening 16 years parallel those of stream chemistry. Statistical comparisons of data on stream chemistry and an acid biological assessment profile (Acid BAP) derived from invertebrate data showed no significant differences between the two years. For pH and ANC, however, values in 2003 were generally lower than those in 1987; this difference likely resulted from higher streamflow in summer 2003. Despite these likely flow-induced changes in summer 2003, an ordination and cluster analysis of macroinvertebrate taxa based on the Acid BAP indicated that the most acidic sites in the upstream half of the East Branch Neversink River form a statistically significant separate cluster consistent with less acidic stream conditions. This analysis is consistent with limited recovery of invertebrate species in the most acidic reaches of the river, but will require additional improvement in stream chemistry before a stronger conclusion can be drawn. Data on the fish and periphytic diatom communities in 2003 indicate that slimy sculpin had not extended their habitat

  14. Morphology and thermal properties of electrospun fatty acids/polyethylene terephthalate composite fibers as novel form-stable phase change materials

    Chen, Changzhong [Key Laboratory of Cellulose and Lignocellulosics Chemistry, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Linge [Key Laboratory of Cellulose and Lignocellulosics Chemistry, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China); Department of Chemistry, University of Sheffield, Sheffield S3 7HF (United Kingdom); Huang, Yong [Key Laboratory of Cellulose and Lignocellulosics Chemistry, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China); State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)

    2008-11-15

    The ultrafine fibers based on the composites of polyethylene terephthalate (PET) and a series of fatty acids, lauric acid (LA), myristic acid (MA), palmitic acid (PA), and stearic acid (SA), were prepared successfully via electrospinning as form-stable phase change materials (PCMs). The morphology and thermal properties of the composite fibers were studied by field emission scanning electron microscopy (FE-SEM) and differential scanning calorimetry (DSC), respectively. It was found that the average fiber diameter increased generally with the content of fatty acid (LA) in the LA/PET composite fibers. The fibers with the low mass ratio maintained cylindrical shape with smooth surface while the quality became worse when the mass ratio is too high (more than 100/100). Moreover, the latent heat of the composite fibers increased with the increase of LA content and the phase transition temperature of the fibers have no obvious variations compared with LA. In contrast, both the latent heat and phase transition temperature of the fatty acid/PET composite fibers varied with the type of the fatty acids, and could be well maintained after 100 heating-cooling thermal cycles, which demonstrated that the composite fibers had good thermal stability and reliability. (author)

  15. The Unusual Acid-Accumulating Behavior during Ripening of Cherimoya (Annona cherimola Mill.) is Linked to Changes in Transcription and Enzyme Activity Related to Citric and Malic Acid Metabolism.

    González-Agüero, Mauricio; Tejerina Pardo, Luis; Zamudio, María Sofía; Contreras, Carolina; Undurraga, Pedro; Defilippi, Bruno G

    2016-01-01

    Cherimoya (Annona cherimola Mill.) is a subtropical fruit characterized by a significant increase in organic acid levels during ripening, making it an interesting model for studying the relationship between acidity and fruit flavor. In this work, we focused on understanding the balance between the concentration of organic acids and the gene expression and activity of enzymes involved in the synthesis and degradation of these metabolites during the development and ripening of cherimoya cv. "Concha Lisa". Our results showed an early accumulation of citric acid and other changes associated with the accumulation of transcripts encoding citrate catabolism enzymes. During ripening, a 2-fold increase in malic acid and a 6-fold increase in citric acid were detected. By comparing the contents of these compounds with gene expression and enzymatic activity levels, we determined that cytoplasmic NAD-dependent malate dehydrogenase (cyNAD-MDH) and mitochondrial citrate synthase (mCS) play important regulatory roles in the malic and citric acid biosynthetic pathways. PMID:27120592

  16. Commutation Processes in Multiresonant ZVS Bridge Converter

    Miroslaw Luft

    2008-01-01

    Full Text Available The analysis of the multiresonant ZVS DC/DC bridge converter is presented. The control system of the converter is basedon the method of frequency control at the constant time of transistor turn-off with a phase shift. The operation of the circuit is givenand the operating range of the converter is defined where ZVS switching operation is assured. Control characteristics are given andthe converter’s efficiency is defined. The circuit’s operation is analysed on the basis of results of the converter simulation tests using Simplorer programme.

  17. PLASMA PROTEIN AND HEMOGLOBIN PRODUCTION : DELETION OF INDIVIDUAL AMINO ACIDS FROM GROWTH MIXTURE OF TEN ESSENTIAL AMINO ACIDS. SIGNIFICANT CHANGES IN URINARY NITROGEN.

    Robscheit-Robbins, F S; Miller, L L; Whipple, G H

    1947-02-28

    Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive

  18. Changes in LDL fatty acid composition as a response to olive oil treatment are inversely related to lipid oxidative damage: The EUROLIVE study

    Cicero, Arrigo F G; Nascetti, Simona; López-Sabater, Maria C; Elosua, Roberto; Salonen, Jukka T; Nyyssönen, Kristiina; Poulsen, Henrik E; Zunft, Hans-Joachim F; Kiesewetter, Holger; de la Torre, Karina; Covas, María-Isabel; Kaikkonen, Jari; Mursu, Jaakko; Koenbick, Corina; Bäumler, Hans; Gaddi, Antonio V

    2008-01-01

    The aim of our study was to assess the changes in the fatty acid composition of low density lipoproteins (LDL) after sustained consumption of olive oil at real-life doses (25 mL/day) and their relationship with lipid oxidative damage.......The aim of our study was to assess the changes in the fatty acid composition of low density lipoproteins (LDL) after sustained consumption of olive oil at real-life doses (25 mL/day) and their relationship with lipid oxidative damage....

  19. Analysis and Design of CLL Resonant Converter for Solar Panel-battery Systems

    D.Ramasubramanian

    2012-12-01

    Full Text Available This paper presents a CLL resonant converter with DSP based Fuzzy Logic Controller (FLC for solar panel to battery charging system. The mathematical model of the converters has been developed and simulated using MATLAB. The state space model of the converter is developed; it is used to analysis the steady state stability of the system. The aim of the proposed converter is to regulate and control of the output voltage from the solar panel voltage. The performance of the proposed converter is validated through experiments with a 75-Watt solar panel. The effectiveness of the controller is verified for supply change and load disturbance. The converter is implemented on a TMS320F2407 Digital Signal Processor with 75-Watt PV system. Comparison between experimental and simulations show a very good agreement and the reliability of fuzzy controller.

  20. Mathematical modeling of a photovoltaic-laser energy converter for iodine laser radiation

    Walker, Gilbert H.; Heinbockel, John H.

    1987-01-01

    Space-based laser power systems will require converters to change laser radiation into electricity. Vertical junction photovoltaic converters are promising devices for this use. A promising laser for the laser power station is the t-C4F9I laser which emits radiation at a wavelength of 1.315 microns. This paper describes the results of mathematical modeling of a photovoltaic-laser energy converter for use with this laser. The material for this photovoltaic converter is Ga(53)In(47)As which has a bandgap energy of 0.94 eV, slightly below the energy of the laser photons (0.943 eV). Results of a study optimizing the converter parameters are presented. Calculated efficiency for a 1000 vertical junction converter is 42.5 percent at a power density of 1 x 10 to the 3d power w/sq cm.

  1. Catalytic converter with thermoelectric generator

    Parise, R.J.

    1998-07-01

    The unique design of an electrically heated catalyst (EHC) and the inclusion of an ECO valve in the exhaust of an internal combustion engine will meet the strict new emission requirements, especially at vehicle cold start, adopted by several states in this country as well as in Europe and Japan. The catalytic converter (CC) has been a most useful tool in pollution abatement for the automobile. But the emission requirements are becoming more stringent and, along with other improvements, the CC must be improved to meet these new standards. Coupled with the ECO valve, the EHC can meet these new emission limits. In an internal combustion engine vehicle (ICEV), approximately 80% of the energy consumed leaves the vehicle as waste heat: out the tail pipe, through the radiator, or convected/radiated off the engine. Included with the waste heat out the tail pipe are the products of combustion which must meet strict emission requirements. The design of a new CC is presented here. This is an automobile CC that has the capability of producing electrical power and reducing the quantity of emissions at vehicle cold start, the Thermoelectric Catalytic Power Generator. The CC utilizes the energy of the exothermic reactions that take place in the catalysis substrate to produce electrical energy with a thermoelectric generator. On vehicle cold start, the thermoelectric generator is used as a heat pump to heat the catalyst substrate to reduce the time to catalyst light-off. Thus an electrically heated catalyst (EHC) will be used to augment the abatement of tail pipe emissions. Included with the EHC in the exhaust stream of the automobile is the ECO valve. This valve restricts the flow of pollutants out the tail pipe of the vehicle for a specified amount of time until the EHC comes up to operating temperature. Then the ECO valve opens and allows the full exhaust, now treated by the EHC, to leave the vehicle.

  2. A gain-of-function mutation in IAA8 alters Arabidopsis floral organ development by change of jasmonic acid level.

    Wang, Jing; Yan, Da-Wei; Yuan, Ting-Ting; Gao, Xiang; Lu, Ying-Tang

    2013-05-01

    Auxin regulates a variety of physiological processes via its downstream factors included Aux/IAAs. In this study, one of these Aux/IAAs, IAA8 is shown to play its role in Arabidopsis development with transgenic plants expressing GFP-mIAA8 under the control of IAA8 promoter, in which IAA8 protein was mutated by changing Pro170 to Leu170 in its conserved domain II. These transgenic dwarfed plants had more lateral branches, short primary inflorescence stems, decreased shoot apical dominance, curled leaves and abnormal flower organs (short petal and stamen, and bent stigmas). Further experiments revealed that IAA8::GFP-mIAA8 plants functioned as gain-of-function mutation to increase GFP-mIAA8 amount probably by stabilizing IAA8 protein against proteasome-mediated protein degradation with IAA8::GFP-IAA8 plants as control. The searching for its downstream factors indicated its interaction with both ARF6 and ARF8, suggesting that IAA8 may involve in flower organ development. This was further evidenced by analyzing the expression of jasmonic acid (JA) biosynthetic genes and JA levels because ARF6 and ARF8 are required for normal JA production. These results indicated that in IAA8::GFP-mIAA8 plants, JA biosynthetic genes including DAD1 (AT2G44810), AOS (AT5G42650) and ORP3 (AT2G06050) were dramatically down-regulated and JA level in the flowers was reduced to 70 % of that in wild-type. Furthermore, exogenous JA application can partially rescue short petal and stamen observed IAA8::GFP-mIAA8 plants. Thus, IAA8 plays its role in floral organ development by changes in JA levels probably via its interaction with ARF6/8 proteins. PMID:23483289

  3. Induction of apoptosis and change of bcl—2 expression in macrophage Ana—1 cells by all—trans retinoic acid

    YINDELING; XIUHAIREN; 等

    1996-01-01

    Macrophage cells play an important role in the initiation and regulation of the immune response.All-trans retinoic acid (ATRA) and its natural and synthetic analogs (retinoids)affect a large number of biological processes.Recently,retinoids have been shown promise in the therapy and prevention of various cancers.However,many interesting questions related to the activities of retinoids remain to be answered:(I) Molecular mechanisms by which retinoids exert their effects;(Ⅱ)why the clinical uses of retinoids give undesirable side effects of varying severity with a higher frequency of blood system symptoms;(Ⅲ)little is known for its impacts on macrophage cells etc.We set up this experiment,therefore,to examine the apoptosis of ATRA on macrophage Ana-1 cell line.Apoptosis of the cells was quantitated,after staining cells with propidium iodide(PI),by both accounting nuclear condensation and flow cytometry.When the cells were treated with ATRA at or higher than 1μM for more than 24h,significant amount of the apoptotic cells was observed.Induction of apoptosis of Ana-1 cells by ATRA was in time-and dose-dependent manners,exhibiting the similar pattern as the apoptosis induced by actinomycin D (ACTD).ATRA treatment of Ana-1 cells also caused the changes of the mRNA levels of apoptosis-associated gene bcl-2,as detected by Northern blot analysis.The temporal changes of bcl-2 expression by ATRA was also parallel to that by ACTD.In conclusion,ATRA can induce apoptosis in macrophage cells,which may be helpful in understanding of immunological functions retinoids.

  4. Buck-Boost/Forward Hybrid Converter for PV Energy Conversion Applications

    Sheng-Yu Tseng; Chien-Chih Chen; Hung-Yuan Wang

    2014-01-01

    This paper presents a charger and LED lighting (discharger) hybrid system with a PV array as its power source for electronic sign indicator applications. The charger adopts buck-boost converter which is operated in constant current mode to charge lead-acid battery and with the perturb and observe method to extract maximum power of PV arrays. Their control algorithms are implemented by microcontroller. Moreover, forward converter with active clamp circuit is operated in voltage regulation cond...

  5. Ferulic Acid Alleviates Changes in a Rat Model of Metabolic Syndrome Induced by High-Carbohydrate, High-Fat Diet

    Ketmanee Senaphan

    2015-08-01

    Full Text Available Metabolic syndrome is a cluster of metabolic abnormalities characterized by obesity, insulin resistance, hypertension and dyslipidemia. Ferulic acid (FA is the major phenolic compound found in rice oil and various fruits and vegetables. In this study, we examined the beneficial effects of FA in minimizing insulin resistance, vascular dysfunction and remodeling in a rat model of high-carbohydrate, high-fat diet-induced metabolic changes, which is regarded as an analogue of metabolic syndrome (MS in man. Male Sprague-Dawley rats were fed a high carbohydrate, high fat (HCHF diet and 15% fructose in drinking water for 16 weeks, where control rats were fed with standard chow diet and tap water. FA (30 or 60 mg/kg was orally administered to the HCHF and control rats during the last six weeks of the study. We observed that FA significantly improved insulin sensitivity and lipid profiles, and reduced elevated blood pressure, compared to untreated controls (p < 0.05. Moreover, FA also improved vascular function and prevented vascular remodeling of mesenteric arteries. The effects of FA in HCHF-induced MS may be realized through suppression of oxidative stress by down-regulation of p47phox, increased nitric oxide (NO bioavailability with up-regulation of endothelial nitric oxide synthase (eNOS and suppression of tumor necrosis factor-α (TNF-α. Our results suggest that supplementation of FA may have health benefits by minimizing the cardiovascular complications of MS and alleviating its symptoms.

  6. Determination of the antioxidant activity based on the content changes in fatty acid methyl esters in vegetable oils

    Housam Haj Hamdo; Zaid Al-Assaf; Warid Khayata

    2014-01-01

    Free radicals,which are generated in several biochemical reactions in the body,have been implicated as mediators of many diseases,including cancer,atherosclerosis and heart diseases.Although the endogenous antioxidants can scavenge these free radicals,they are often insufficient to maintain the in vivo redox balance.The antioxidant activity (AOA) was examined by addition of each tested antioxidants [alpha-tocopherol (a-T),beta-tocopherol (β-T),gamma-tocopherol (γ-T),delta-tocopherol (δ-T),butylated hydroxyanisole (BHA),2,6-di-tert-butyl-4-methylphenol (BHT),and ascorbyle palmitate (AP)] to four types of different vegetable oils (sunflower oil,soybean oil,corn oil and olive oil).Moreover,content changes in fatty acids were then investigated every 3 months during the storage period.The results showed that the AOA was different among the tested antioxidants.The AOA for BHA was the most for different types of oil compared with other antioxidants,whereas the δ-T possessed the lowest AOA.

  7. Effect of naphthalene acetic acid on adventitious root development and associated physiological changes in stem cutting of Hemarthria compressa.

    Yan-Hong Yan

    Full Text Available In order to find a way to induce rooting on cuttings of Hemarthria compressa cv. Ya'an under controlled conditions, a project was carried out to study the effect of naphthalene acetic acid (NAA on rooting in stem cuttings and related physiological changes during the rooting process of Hemarthria compressa. The cuttings were treated with five concentrations of NAA (0, 100, 200 300, 400 mg/l at three soaking durations (10, 20, 30 minutes, and cuttings without treatment were considered as control. Samples were planted immediately into pots after treatment. IAA-oxidase (IAAO activity, peroxidase (POD activity and polyphenol oxidase (PPO activity were determined after planting. Results showed that NAA had positive effect on rooting at the concentration of 200 mg/l compared to other concentrations at 30 days after planting (DAP. Among the three soaking durations, 20 minutes (min of 200 mg/l NAA resulted in higher percentages of rooting, larger numbers of adventitious roots and heavier root dry weight per cutting. The lowest IAAO activity was obtained when soaked at 200 mg/l NAA for 20 min soaking duration. This was consistent with the best rooting ability, indicating that the lower IAAO activity, the higher POD activity and PPO activity could be used as an indicator of better rooting ability for whip grass cuttings and might serve as a good marker for rooting ability in cuttings.

  8. Potential for Increased Photosynthetic Performance and Crop Productivity in Response to Climate Change: role of CBFs and Gibberellic Acid

    Norman Peter Andrew Huner

    2014-04-01

    Full Text Available We propose that targeting the dwarf phenotype, enhanced photosynthetic performance typically associated with the cold acclimation of winter cultivars of rye (Secale cereale L., wheat (Triticum aestivum L. and Brassica napus L. may provide a novel approach to improve crop yield and productivity under abiotic as well as biotic stress conditions. In support of this hypothesis, we provide the physiological, biochemical and molecular evidence that the dwarf phenotype induced by cold acclimation is coupled to significant enhancement in photosynthetic performance, resistance to photoinhibition and a decreased dependence on photoprotection through nonphotochemical quenching which result in enhanced biomass production and ultimately increased seed yield. These system-wide changes at the levels of phenotype, physiology and biochemistry appear to be governed by the family of C-repeat / dehydration-responsive family of transcription factors (CBF/DREB1. We relate this phenomenon to the semi-dwarf, gibberellic acid insensitive, cereal varieties developed during the green revolution of the early 1960s and 1970s. We suggest that genetic manipulation of the family of C-repeat / dehydration-responsive element binding transcription factors (CBF/DREB1 may provide a novel approach for the maintenance and perhaps even the enhancement of plant productivity under conditions of sub-optimal growth conditions predicted for our future climate.

  9. Potential for Increased Photosynthetic Performance and Crop Productivity in Response to Climate Change: role of CBFs and Gibberellic Acid

    Huner, Norman; Dahal, Keshav; Kurepin, Leonid; Savitch, Leonid; Singh, Jas; Ivanov, Alexander; Kane, Khalil; Sarhan, Fathey

    2014-04-01

    We propose that targeting the dwarf phenotype, enhanced photosynthetic performance typically associated with the cold acclimation of winter cultivars of rye (Secale cereale L.), wheat (Triticum aestivum L.) and Brassica napus L. may provide a novel approach to improve crop yield and productivity under abiotic as well as biotic stress conditions. In support of this hypothesis, we provide the physiological, biochemical and molecular evidence that the dwarf phenotype induced by cold acclimation is coupled to significant enhancement in photosynthetic performance, resistance to photoinhibition and a decreased dependence on photoprotection through nonphotochemical quenching which result in enhanced biomass production and ultimately increased seed yield. These system-wide changes at the levels of phenotype, physiology and biochemistry appear to be governed by the family of C-repeat / dehydration-responsive family of transcription factors (CBF/DREB1). We relate this phenomenon to the semi-dwarf, gibberellic acid insensitive, cereal varieties developed during the “green revolution” of the early 1960s and 1970s. We suggest that genetic manipulation of the family of C-repeat / dehydration-responsive element binding transcription factors (CBF/DREB1) may provide a novel approach for the maintenance and perhaps even the enhancement of plant productivity under conditions of sub-optimal growth conditions predicted for our future climate.

  10. Role of succinic acid in chemical evolution

    Negron-Mendoza, A.; Ponnamperuma, C.

    1982-01-01

    Succinic acid is converted into other carboxylic acids by ionizing radiation. The results obtained have been correlated with the ready formation of this compound in prebiotic experiments. Its role in biological systems may be related to its prebiotic occurrence.

  11. Phytohemagglutinin-induced change in the distribution of acidic sugars in surface membrane of lymphoid cells and blocking of the radiation effect. [X radiation

    Sato, C.; Kojima, K.

    1976-01-01

    Cell electrophoretic mobilities (EPM) of cultured lymphoblastoid cells were measured after removal of acidic sugars to investigate whether the localization of these acidic sugars was altered by the action of phytohaemagglutinin (PHA). After treatment with neuraminidase or hyaluronidase, the EPM of control cells decreased 50.1 and 0.3 percent, while that of PHA-treated cells decreased 25.2 and 39.0 percent, respectively. These results suggest that hyaluronic acid appeared at the periphery of the cell surface in place of some sialic acid after incubation with PHA. The change became evident after 10 min incubation with PHA and reached its maximum after 20 min at 37/sup 0/C, but no change was observed at 4/sup 0/C. The EPM decreased with time after x-irradiation, and reached a minimum value after 4 h. The addition of PHA to culture before irradiation completely blocked the x-ray mediated reduction in EPM. PHA administration after irradiation stopped further EPM reduction. These results seem to suggest a rapid rearrangement of membrane molecules linking with the receptors and acidic sugars induced by PHA, and blocking of further conformation change by x-irradiation.

  12. Phytohemagglutinin-induced change in the distribution of acidic sugars in surface membrane of lymphoid cells and blocking of the radiation effect

    Cell electrophoretic mobilities (EPM) of cultured lymphoblastoid cells were measured after removal of acidic sugars to investigate whether the localization of these acidic sugars was altered by the action of phytohaemagglutinin (PHA). After treatment with neuraminidase or hyaluronidase, the EPM of control cells decreased 50.1 and 0.3 percent, while that of PHA-treated cells decreased 25.2 and 39.0 percent, respectively. These results suggest that hyaluronic acid appeared at the periphery of the cell surface in place of some sialic acid after incubation with PHA. The change became evident after 10 min incubation with PHA and reached its maximum after 20 min at 370C, but no change was observed at 40C. The EPM decreased with time after x-irradiation, and reached a minimum value after 4 h. The addition of PHA to culture before irradiation completely blocked the x-ray mediated reduction in EPM. PHA administration after irradiation stopped further EPM reduction. These results seem to suggest a rapid rearrangement of membrane molecules linking with the receptors and acidic sugars induced by PHA, and blocking of further conformation change by x-irradiation

  13. Power Electronics Converters for Wind Turbine Systems

    Blaabjerg, Frede; Liserre, Marco; Ma, Ke

    2012-01-01

    . In this paper, power converter technologies are reviewed with focus on existing ones and on those that have potential for higher power but which have not been yet adopted due to the important risk associated with the high-power industry. The power converters are classified into single- and multicell topologies......, but continuously cost and reliability are important issues to be addressed....

  14. Passive Resonant Bidirectional Converter with Galvanic Barrier

    Rosenblad, Nathan S. (Inventor)

    2014-01-01

    A passive resonant bidirectional converter system that transports energy across a galvanic barrier includes a converter using at least first and second converter sections, each section including a pair of transfer terminals, a center tapped winding; a chopper circuit interconnected between the center tapped winding and one of the transfer terminals; an inductance feed winding interconnected between the other of the transfer terminals and the center tap and a resonant tank circuit including at least the inductance of the center tap winding and the parasitic capacitance of the chopper circuit for operating the converter section at resonance; the center tapped windings of the first and second converter sections being disposed on a first common winding core and the inductance feed windings of the first and second converter sections being disposed on a second common winding core for automatically synchronizing the resonant oscillation of the first and second converter sections and transferring energy between the converter sections until the voltage across the pairs of transfer terminals achieves the turns ratio of the center tapped windings.

  15. Modeling and Simulation of Matrix Converter

    Liu, Fu-rong; Klumpner, Christian; Blaabjerg, Frede

    2005-01-01

    This paper discusses the modeling and simulation of matrix converter. Two models of matrix converter are presented: one is based on indirect space vector modulation and the other is based on power balance equation. The basis of these two models is• given and the process on modeling is introduced in...

  16. High Precision Current Measurement for Power Converters

    Bastos, M. Cerqueira

    2016-01-01

    The accurate measurement of power converter currents is essential to controlling and delivering stable and repeatable currents to magnets in particle accelerators. This paper reviews the most commonly used devices for the measurement of power converter currents and discusses test and calibration methods.

  17. Power Converters Secure Electronics in Harsh Environments

    2013-01-01

    In order to harden power converters for the rigors of space, NASA awarded multiple SBIR contracts to Blacksburg, Virginia-based VPT Inc. The resulting hybrid DC-DC converters have proven valuable in aerospace applications, and as a result the company has generated millions in revenue from the product line and created four high-tech jobs to handle production.

  18. Switched-mode converters (one quadrant)

    Barrade, P

    2006-01-01

    Switched-mode converters are DC/DC converters that supply DC loads with a regulated output voltage, and protection against overcurrents and short circuits. These converters are generally fed from an AC network via a transformer and a conventional diode rectifier. Switched-mode converters (one quadrant) are non-reversible converters that allow the feeding of a DC load with unipolar voltage and current. The switched-mode converters presented in this contribution are classified into two families. The first is dedicated to the basic topologies of DC/DC converters, generally used for low- to mid-power applications. As such structures enable only hard commutation processes, the main drawback of such topologies is high commutation losses. A typical multichannel evolution is presented that allows an interesting decrease in these losses. Deduced from this direct DC/DC converter, an evolution is also presented that allows the integration of a transformer into the buck and the buck–boost structure. This enables an int...

  19. Convertible Bonds: Default Risk and Uncertain Volatility

    Huang, Haishi

    2009-01-01

    Within a default intensity approach we discuss the optimal exercise of the callable and convertible bonds. Pricing bounds for convertible bonds are derived in an uncertain volatility model, i.e. when the volatility of the stock price process lies between two extreme values.

  20. Underwater noise from a wave energy converter

    Tougaard, Jakob

    A recent addition to the anthropogenic sources of underwater noise is offshore wave energy converters. Underwater noise was recorded from the Wavestar wave energy converter located at Hastholm, Denmark (57°7.73´N, 8°37.23´E). The Wavestar is a full-scale test and demonstration converter of the ab...... to affect seals and porpoises cannot be generalised. Nevertheless, the results clearly demonstrate that it is possible to harvest wave energy in a way which does not add substantially to the increasing levels of anthropogenic noise in the ocean.......A recent addition to the anthropogenic sources of underwater noise is offshore wave energy converters. Underwater noise was recorded from the Wavestar wave energy converter located at Hastholm, Denmark (57°7.73´N, 8°37.23´E). The Wavestar is a full-scale test and demonstration converter...... of the absorber type. During recordings the converter was operating close to maximum power output (nominal capacity of 110 kW). During operation the independently operating absorbers float semi-submerged in the water and wave-generated up-and-down motion is converted into hydraulic pressure by means of pistons...

  1. Spatial resolution of plastic scintillation converter

    The authors obtain point- and line-scattering functions and a modulation-transfer function for scintillation plates on a polystyrene base used as converters of x-ray images by optical transfer by means of an objective. For x-ray energies of 1-8 MeV, the spatial resolution of the converter is 2.5-1.0 mm-1

  2. Utilization of Nonlinear Converters for Audio Amplification

    Iversen, Niels; Birch, Thomas; Knott, Arnold

    2012-01-01

    introduction of non-linear converters for audio amplication defeats this limitation. A Cuk converter, designed to deliver an AC peak output voltage twice the supply voltage, is presented in this paper. A 3V prototype has been developed to prove the concept. The prototype shows that it is possible to achieve an...

  3. 3 SC for grid connected converters

    Balogh, A.; Varga, E.; Varjasi, I. [Budapest Univ. of Technology and Economics, Budapest (Hungary). Dept. of Automation and Applied Informatics

    2008-07-01

    There are several grid connected converters in the modern grid system. They are usually converters for renewable energy sources, industrial 4 quadrant drives and other converters with direct current link. These converters are connected to the grid using a 3 phase bridge. Standards dictate the maximal harmonic emission and the maximal reactive current for the grid connected converters. For a converter working at nominal power, this means close to unity power factor. The harmonic emission could be limited with high switching frequency and/or with large harmonic filters. Additional financial issues are the efficiency, the small size and weight. Hardware solutions for increasing efficiency are being sought, although the energy required, especially the renewable energy, is expensive. Efficiency is one of the most important parameters of a grid connected system. The paper discussed the structure of the converter, standard control strategies, the three state control (3SC) method, and power factor correction with 3SC. Experimental results were also presented. It was concluded that with the new developed discontinuous current control, a high efficiency and reliable grid connected converter could be created, which satisfies the prescriptions and limitations of the standards. The auxiliary RPC control could make both inductive and capacitive reactive power and is able to inject current harmonics into the grid compensating the distortion of the grid voltage. 12 refs., 2 tabs.

  4. Converter indivíduos, mudar culturas Converting individuals, changing cultures

    Reginaldo Prandi

    2008-11-01

    Full Text Available Religiões diferentes concebem e tratam diversamente seus alvos: seus adeptos, antigos e novos. Procura-se neste texto analisar certas relações que distintas correntes religiosas estabelecem com as culturas e os indivíduos na América Latina, especialmente no Brasil. As religiões têm interpretações distintas do que seja a cultura, e essas definições ajudam a moldar suas estratégias de conversão e reação ao avanço de religiões oponentes. Para efeito de discussão, o artigo considera como um eixo hipotético um futuro não distante em que a América Latina teria uma maioria evangélica em sua população, perguntando-se o que aconteceria com a suposta cultura católica latino-americana se caso tal supremacia evangélica viesse de fato a se constituir.Different religions conceive and treat their target public - their followers, old and new - in distinct ways. This text analyzes some of the relations established by different religious currents with cultures and individuals in Latin America, especially Brazil. Contemporary religions have diverging interpretations of what culture is - definitions which help shape their strategies for conversion and their responses to the advance of rival religions. For the purposes of debate, the article hypothesizes a not too distant future in which the majority of Latin America's population is Evangelical and asks what would happen to the supposedly Catholic Latin America culture if this supremacy were indeed to become a reality.

  5. Propeptide and glutamate-containing substrates bound to the vitamin K-dependent carboxylase convert its vitamin K epoxidase function from an inactive to an active state

    Sugiura, Isamu; Furie, Bruce; Walsh, Christopher T.; Furie, Barbara C.

    1997-01-01

    The vitamin K-dependent γ-glutamyl carboxylase catalyzes the posttranslational conversion of glutamic acid to γ-carboxyglutamic acid in precursor proteins containing the γ-carboxylation recognition site (γ-CRS). During this reaction, glutamic acid is converted to γ-carboxyglutamic acid while vitamin KH2 is converted to vitamin K 2,3-epoxide. Recombinant bovine carboxylase was purified free of γ-CRS-containing propeptide and endogenous substrate in a single-step immunoaffinity procedure. We sh...

  6. Change in the Content of Salicylic Acid and in the Activities of Phenylalanine Ammonia-Lyase and Catalase in Wheat Seedling Roots Under the Effect of Azospirillum Lectins

    Alen'kina S.A.

    2012-05-01

    Full Text Available We investigated the time course of changes in the endogenous content of salicylic acid, the ratio between the acid's free and bound forms, and changes in the activities of phenylalanine ammonia-lyase and catalase in wheat seedling roots under the effect of the lectins of two strains of the associative nitrogen-fixing bacterium Azospirillum: A. brasilense Sp7 and its mutant defective in lectin activity, A. brasilense Sp7.2.3. Differences in plant response to the action of the lectins from these two strains were established. On the basis of the obtained data, a model was proposed for lectin-assisted induction of resistance, according to which the lectin effect on the roots of seedlings results in accumulation of free salicylic acid, which inhibits catalase activity, ultimately leading to accumulation of hydrogen peroxide and to formation of induced resistance.

  7. SPECTRAL ANALYSIS OF BUCK AND SEPIC CONVERTERS

    CHAKIB ALAOUI

    2011-02-01

    Full Text Available Switched mode power converters generate harmonic currents, which will be injected into the utility grid, causing distortion of the utility waveform. They also become a source for the generation of EMI, which may affect the communication systems. This work is about the design and evaluation of the two most frequently used SMPS used in step down mode of operation: the Buck converter and the Sepic converter working in step-down mode of operation. These converters were designed using optimized equations for their components ratings. Simulation results show that although the Buck output voltage is low in harmonics, it has high harmonic contents in currents circulating in its inductor and diode, and hence requires strong filtering. The Sepic converterhas lower harmonic contents than the Buck converter.

  8. Switched Mode Four-Quadrant Converters

    Thurel, Y

    2015-01-01

    This paper was originally presented at CAS-2004, and was slightly modified for CAS-2014. It presents a review of the key parameters that impact the design choices for a true four-quadrant power converter, in the range 1-10 kW, mainly based on switching mode converter topology. This paper will first describe the state-of-the-art for this power converter family, giving the drawbacks and advantages of different possible solutions. It will also present practical results obtained from the CERN-designed converter. It will finally give some important tips regarding critical phases like test one, when conducting a project dealing with this type of power converter.

  9. Qualitative model of a plasma photoelectric converter

    Gorbunov, N. A.; Flamant, G.

    2009-01-01

    A converter of focused optical radiation into electric current is considered on the basis of the photovoltaic effect in plasmas. The converter model is based on analysis of asymmetric spatial distributions of charge particle number density and ambipolar potential in the photoplasma produced by external optical radiation focused in a heat pipe filled with a mixture of alkali vapor and a heavy inert gas. Energy balance in the plasma photoelectric converter is analyzed. The conditions in which the external radiation energy is effectively absorbed in the converter are indicated. The plasma parameters for which the energy of absorbed optical radiation is mainly spent on sustaining the ambipolar field in the plasma are determined. It is shown that the plasma photoelectric converter makes it possible to attain a high conversion efficiency for focused solar radiation.

  10. Flow parameters of IC engine catalytic converters

    Zmudka, Z.; Postrzednik, S. [Silesian Univ. of Tech., Gliwice (Poland)

    2007-07-01

    Conversion rate of harmful substances is the principal parameter of catalyst work in respect of ecology. However, resistance of exhaust gas flow through the catalytic converter is also essential problem, apart from its chemical efficiency because fitting the catalyst in exhaust system alters flow characteristic of this system significantly. Catalytic converter can be treated as local or linear resistance element of exhaust system. The first model, in which flow resistance generated by a catalyst is treated as local resistance, is more simplified. Resistance number of the converter was calculated using Darcy model. In the second case, exhaust gas flow resistance through catalyst is treated as linear resistance with energy dissipation (linear frictional resistance) distributed linearly along way of exhaust gas flow. Friction number for the tested converter was calculated and analysed. The problem has been illustrated by results of experimental researches of three-way catalytic converter installed in exhaust system of spark ignition engine and its basic analysis. (orig.)

  11. A Positive Buck Boost Converter with Mode Select Circuit and Feed Forward Techniques Using Fuzzy Logic Controller

    Latha. S. C

    2014-11-01

    Full Text Available The portable devices development of semiconductor manufacturing technology, conversion efficiency, power consumption, and the size of devices have become the most important design criteria of switching power converters. For portable applications better conveniences extension of battery life and improves the conversion efficiency of power converters .It is essential to develop accurate switching power converters, which can reduce more wasted power energy. The proposed topology can achieve faster transient responses when the supply voltages are changed for the converter by making use of the feed forward network .With mode select circuit the conduction & switching losses are reduced the positive buck–boost converter operate in buck, buck–boost, or boost converter. By adding feed-forward techniques, the proposed converter can improve transient response when the supply voltages are changed. The designing, modeling & experimental results were verified in MATLAB/ Simulink. The fuzzy logic controller is used as controller.

  12. PERFORMANCE ANALYSIS OF 2D CONVERTER BY COMBINING SR & KY CONVERTERS

    V. Manoj Kumar

    2014-03-01

    Full Text Available Most of the portable equipments use battery as power source. The increasing use of low voltage portable devices and growing requirements of functionalities embedded into such devices. Thus an efficient power management technique is needed for longer battery life for them. Highly variable nature of batteries systems often require supply voltages to be both higher and lower than the battery. This is most efficiently generated by a buck-boost switching converter. But here the converter efficiency is decreased since the power loss occurs in the storage devices. Step by step, process of designing, feedback control and simulation of a novel voltage-buck boost converter, combining KY and synchronous Rectifier buck converter for battery power applications. Unlike the traditional buck–boost converter, this converter has the positive output voltage and system is stable, different from the negative output voltage and low stable of the traditional inverting buck–boost converters. Since such a converter operates in continuous conduction mode. Also it possesses the non-pulsating output current, thereby not only decreasing the current stress on the output capacitor but also reducing the output voltage ripple. Both the KY converter and the synchronous buck converter, combined into a positive buck– boost converter, uses the same power switches. Here it makes the circuit to be compact and the corresponding cost to be down. Voltage conversion ratio is 2D,so it is also called 2D converter.

  13. Changes in LDL fatty acid composition as a response to olive oil treatment are inversely related to lipid oxidative damage: The EUROLIVE study

    Cicero, Arrigo F G; Nascetti, Simona; López-Sabater, Maria C; Elosua, Roberto; Salonen, Jukka T; Nyyssönen, Kristiina; Poulsen, Henrik E; Zunft, Hans-Joachim F; Kiesewetter, Holger; de la Torre, Karina; Covas, María-Isabel; Kaikkonen, Jari; Mursu, Jaakko; Koenbick, Corina; Bäumler, Hans; Gaddi, Antonio V

    2008-01-01

    The aim of our study was to assess the changes in the fatty acid composition of low density lipoproteins (LDL) after sustained consumption of olive oil at real-life doses (25 mL/day) and their relationship with lipid oxidative damage....

  14. Chromium picolinate and conjugated linoleic acid do not synergistically influence diet- and exercise-induced changes in body composition and health indexes in overweight women

    Objective: This study assessed the effects of combined chromium picolinate (CP) and conjugated linoleic acid (CLA) supplementation on energy-restriction and exercise-induced changes in body composition, glucose metabolism, lipid-lipoprotein profile, and blood pressure in overweight, pre-menopausal w...

  15. Improvements in glucose tolerance and insulin sensitivity after lifestyle intervention are related to changes in serum fatty acid profile and desaturase activities: the SLIM study

    Corpeleijn, E.; Feskens, E.J.M.; Jansen, E.H.J.M.; Mensink, M.R.; Saris, W.H.M.; Bruin, de T.W.A.; Blaak, E.E.

    2006-01-01

    AIMS/HYPOTHESIS: The aim of this study was to investigate whether lifestyle intervention-induced changes in serum fatty acid profile of cholesteryl esters and estimated desaturase activities are related to improvements in insulin sensitivity in subjects at risk of type 2 diabetes. MATERIALS AND METH

  16. Improvements in glucose tolerance and insulin sensitivity after lifestyle intervention are related to changes in serum fatty acid profile and desaturase activities : the SLIM study

    Corpeleijn, E.; Feskens, E. J. M.; Jansen, E. H. J. M.; Mensink, M.; Saris, W. H. M.; de Bruin, T. W. A.; Blaak, E. E.

    2006-01-01

    Aims/hypothesis: The aim of this study was to investigate whether lifestyle intervention-induced changes in serum fatty acid profile of cholesteryl esters and estimated desaturase activities are related to improvements in insulin sensitivity in subjects at risk of type 2 diabetes. Materials and meth

  17. Boost matrix converters in clean energy systems

    Karaman, Ekrem

    This dissertation describes an investigation of novel power electronic converters, based on the ultra-sparse matrix topology and characterized by the minimum number of semiconductor switches. The Z-source, Quasi Z-source, Series Z-source and Switched-inductor Z-source networks were originally proposed for boosting the output voltage of power electronic inverters. These ideas were extended here on three-phase to three-phase and three-phase to single-phase indirect matrix converters. For the three-phase to three-phase matrix converters, the Z-source networks are placed between the three-switch input rectifier stage and the output six-switch inverter stage. A brief shoot-through state produces the voltage boost. An optimal pulse width modulation technique was developed to achieve high boosting capability and minimum switching losses in the converter. For the three-phase to single-phase matrix converters, those networks are placed similarly. For control purposes, a new modulation technique has been developed. As an example application, the proposed converters constitute a viable alternative to the existing solutions in residential wind-energy systems, where a low-voltage variable-speed generator feeds power to the higher-voltage fixed-frequency grid. Comprehensive analytical derivations and simulation results were carried out to investigate the operation of the proposed converters. Performance of the proposed converters was then compared between each other as well as with conventional converters. The operation of the converters was experimentally validated using a laboratory prototype.

  18. Alteration of introns in a hyaluronan synthase 1 (HAS1 minigene convert Pre-mRNA [corrected] splicing to the aberrant pattern in multiple myeloma (MM: MM patients harbor similar changes.

    Jitra Kriangkum

    Full Text Available Aberrant pre-mRNA splice variants of hyaluronan synthase 1 (HAS1 have been identified in malignant cells from cancer patients. Bioinformatic analysis suggests that intronic sequence changes can underlie aberrant splicing. Deletions and mutations were introduced into HAS1 minigene constructs to identify regions that can influence aberrant intronic splicing, comparing the splicing pattern in transfectants with that in multiple myeloma (MM patients. Introduced genetic variations in introns 3 and 4 of HAS1 as shown here can promote aberrant splicing of the type detected in malignant cells from MM patients. HAS1Vd is a novel intronic splice variant first identified here. HAS1Vb, an intronic splice variant previously identified in patients, skips exon 4 and utilizes the same intron 4 alternative 3'splice site as HAS1Vd. For transfected constructs with unaltered introns 3 and 4, HAS1Vd transcripts are readily detectable, frequently to the exclusion of HAS1Vb. In contrast, in MM patients, HAS1Vb is more frequent than HAS1Vd. In the HAS1 minigene, combining deletion in intron 4 with mutations in intron 3 leads to a shift from HAS1Vd expression to HAS1Vb expression. The upregulation of aberrant splicing, exemplified here by the expression of HAS1Vb, is shown here to be influenced by multiple genetic changes in intronic sequences. For HAS1Vb, this includes enhanced exon 4 skipping and increased usage of alternative 3' splice sites. Thus, the combination of introduced mutations in HAS1 intron3 with introduced deletions in HAS1 intron 4 promoted a shift to an aberrant splicing pattern previously shown to be clinically significant. Most MM patients harbor genetic variations in intron 4, and as shown here, nearly half harbor recurrent mutations in HAS1 intron 3. Our work suggests that aberrant intronic HAS1 splicing in MM patients may rely on intronic HAS1 deletions and mutations that are frequent in MM patients but absent from healthy donors.

  19. Changes in lipid content and fatty acid composition along the reproductive cycle of the freshwater mussel Dreissena polymorpha: Its modulation by clofibrate exposure

    Lazzara, Raimondo; Fernandes, Denise, E-mail: deniseferna@gmail.com; Faria, Melissa; Lopez, Jordi F.; Tauler, Roma; Porte, Cinta, E-mail: cinta.porte@cid.csic.es

    2012-08-15

    Total lipids and fatty acid profiles were determined along the reproductive cycle of the zebra mussel (Dreissena polymorpha). A total of 33 fatty acids with carbon atoms from 14 to 22 were identified: palmitic acid (16:0) was the most abundant fatty acid (13-24%) followed by docosahexaenoic acid (DHA; 22:6n-3), eicosapentaenoic acid (EPA; 20:5n-3) and palmitoleic acid (16:1n-7). Some individual fatty acids (16:0, 16:2n-4, 18:1n-7, 18:2n-6, 18:3n-4, 18:4n-3, 20:4n-3, 20:5n-3) were strongly related to reproductive events, while others having structural-type functions (18:0 and 22:6n-3) were rather stable during the study period. Multivariate analysis of the whole data set using the multivariate curve resolution alternating least squares method confirmed the strong relationship of fatty acid profiles with the reproductive cycle of zebra mussel. Additionally, the effects of the pharmaceutical clofibrate on lipid composition and fatty acid profiles were assessed following 7-day exposure of zebra mussels to a wide range of concentrations (20 ng/L to 2 mg/L). A significant reduction in total triglycerides (38%-48%) together with an increase in the amount of fatty acids per gram wet weight (1.5- to 2.2-fold) was observed in the exposed mussels. This work highlights the ability of clofibrate to induce changes on the lipidome of zebra mussels at concentrations as low as 200 ng/L. -- Highlights: Black-Right-Pointing-Pointer Clofibrate exposure leads to a reduction of total triglycerides in zebra mussel. Black-Right-Pointing-Pointer The amount of fatty acids per gram wet weight increased in exposed mussels. Black-Right-Pointing-Pointer The effects were evidenced at concentrations of clofibrate as low as 200 ng/L. Black-Right-Pointing-Pointer Fatty acid profiles were closely related to reproductive events.

  20. Changes in lipid content and fatty acid composition along the reproductive cycle of the freshwater mussel Dreissena polymorpha: Its modulation by clofibrate exposure

    Total lipids and fatty acid profiles were determined along the reproductive cycle of the zebra mussel (Dreissena polymorpha). A total of 33 fatty acids with carbon atoms from 14 to 22 were identified: palmitic acid (16:0) was the most abundant fatty acid (13–24%) followed by docosahexaenoic acid (DHA; 22:6n−3), eicosapentaenoic acid (EPA; 20:5n−3) and palmitoleic acid (16:1n−7). Some individual fatty acids (16:0, 16:2n−4, 18:1n−7, 18:2n−6, 18:3n−4, 18:4n−3, 20:4n−3, 20:5n−3) were strongly related to reproductive events, while others having structural-type functions (18:0 and 22:6n−3) were rather stable during the study period. Multivariate analysis of the whole data set using the multivariate curve resolution alternating least squares method confirmed the strong relationship of fatty acid profiles with the reproductive cycle of zebra mussel. Additionally, the effects of the pharmaceutical clofibrate on lipid composition and fatty acid profiles were assessed following 7-day exposure of zebra mussels to a wide range of concentrations (20 ng/L to 2 mg/L). A significant reduction in total triglycerides (38%–48%) together with an increase in the amount of fatty acids per gram wet weight (1.5- to 2.2-fold) was observed in the exposed mussels. This work highlights the ability of clofibrate to induce changes on the lipidome of zebra mussels at concentrations as low as 200 ng/L. -- Highlights: ► Clofibrate exposure leads to a reduction of total triglycerides in zebra mussel. ► The amount of fatty acids per gram wet weight increased in exposed mussels. ► The effects were evidenced at concentrations of clofibrate as low as 200 ng/L. ► Fatty acid profiles were closely related to reproductive events.