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Sample records for acid base status

  1. Acid-base status in dietary treatment of phenylketonuria.

    PubMed

    Manz, F; Schmidt, H; Schärer, K; Bickel, H

    1977-10-01

    Blood acid-base status, serum electrolytes, and urine pH were examined in 64 infants and children with phenylketonuria (PKU) treated with three different low phenylalanine protein hydrolyzates (Aponti, Cymogran, AlbumaidXP) and two synthetic amino acid mixtures (Aminogran, PAM). The formulas caused significant differences in acid-base status, serum potassium, and chloride, and in urine pH. In acid-base balance studies in two patients with PKU, Aponti, PAM, and two modifications of PAM (P2 + P3) were given. We observed a change from mild alkalosis to increasing metabolic acidosis from Aponti (serum bicarbonate 25,8 mval/liter) to P3 (24,0Y, P2 (19, 3) and PAM (17,0). Urine pH decreased and renal net acid excretion increased. In the formulas PAM, P2 and P3 differences in renal net acid excretion correlated with differences in chloride and sulfur contents of the diets and of the urines. New modifications of AlbumaidXP and of PAM, prepared according to our recommendations, showed normal renal net acid excretion (1 mEq/kg/24 hr) in a balance study performed in one patient with PKU and normal acid base status in 20 further patients.

  2. Evolution of the Acid-Base Status in Cardiac Arrest

    PubMed Central

    Carrasco G., Hugo A.; Oletta L., José F.

    1973-01-01

    In a study of the evolution of acid-base status in 26 patients who had cardiopulmonary arrest in the operating room, it appeared that: The determination of acid-base status within the first hour post-cardiac arrest is useful in differentiating final survivors from non-survivors. Respiratory or combined acidosis carries a poor prognosis not evidenced for metabolic acidosis. Late respiratory complications are more frequent in patients with initial combined acidosis. Treatment should be instituted on the basis of frequent determinations of acidbase status, since accurate diagnosis of degree and type of acidosis cannot be done on clinical grounds only. Recovery of consciousness is influenced by the type and severity of acidosis, less so by duration of arrest; and that high pCO2 is associated frequently with unconsciousness after recovery of circulatory function. PMID:4709532

  3. The normal acid-base status of mice.

    PubMed

    Iversen, Nina K; Malte, Hans; Baatrup, Erik; Wang, Tobias

    2012-03-15

    Rodent models are commonly used for various physiological studies including acid-base regulation. Despite the widespread use of especially genetic modified mice, little attention have been made to characterise the normal acid-base status in these animals in order to reveal proper control values. Furthermore, several studies report blood gas values obtained in anaesthetised animals. We, therefore, decided to characterise blood CO(2) binding characteristic of mouse blood in vitro and to characterise normal acid-base status in conscious BALBc mice. In vitro CO(2) dissociation curves, performed on whole blood equilibrated to various PCO₂ levels in rotating tonometers, revealed a typical mammalian pK' (pK'=7.816-0.234 × pH (r=0.34)) and a non-bicarbonate buffer capacity (16.1 ± 2.6 slyke). To measure arterial acid-base status, small blood samples were taken from undisturbed mice with indwelling catheters in the carotid artery. In these animals, pH was 7.391 ± 0.026, plasma [HCO(3)(-)] 18.4 ± 0.83 mM, PCO₂ 30.3 ± 2.1 mm Hg and lactate concentration 4.6 ± 0.7 mM. Our study, therefore, shows that mice have an arterial pH that resembles other mammals, although arterial PCO₂ tends to be lower than in larger mammals. However, pH from arterial blood sampled from mice anaesthetised with isoflurane was significantly lower (pH 7.239 ± 0.021), while plasma [HCO(3)(-)] was 18.5 ± 1.4 mM, PCO₂ 41.9 ± 2.9 mm Hg and lactate concentration 4.48 ± 0.67 mM. Furthermore, we measured metabolism and ventilation (V(E)) in order to determine the ventilation requirements (VE/VO₂) to answer whether small mammals tend to hyperventilate. We recommend, therefore, that studies on acid-base regulation in mice should be based on samples taken for indwelling catheters rather than cardiac puncture of terminally anaesthetised mice.

  4. Differential sensitivity to capture stress assessed by blood acid-base status in five carcharhinid sharks.

    PubMed

    Mandelman, John W; Skomal, Gregory B

    2009-04-01

    Stress from fishing capture can incite potentially lethal physiological changes in fishes. Blood acid-base status has routinely been utilized to gauge the magnitude of the stress response, which is dependent on the nature of the capture event and metabolic capacity of the species in question. The mortality induced by demersal longline capture has been shown to vary among taxonomically similar carcharhinid elasmobranchs. In this study, we aimed to: (1) quantify and compare blood acid-base disturbances associated with longline capture in five carcharhinid species; (2) examine the extent to which these disturbances correspond with reported at-vessel mortality rates; and (3) investigate how interspecific differences in the physiological stress response could relate to life history, ecology, and phylogeny. Results showed that blood acid-base disturbances from longline-capture varied between species, with relative degrees of disturbance by species proportional to previously reported at-vessel mortality rates. In addition, the degree in which metabolic and respiratory acidoses influenced relative depressions in blood pH also differed by species. The differences in blood acid-base status point to discrepancies in the aerobic and anaerobic capacities among these taxonomically similar species, and are important when considering the effects of, and possible means to mitigate deleterious consequences from, longline fishing capture. PMID:18846381

  5. KINEMATIC VARIABLES AND BLOOD ACID-BASE STATUS IN THE ANALYSIS OF COLLEGIATE SWIMMERS’ ANAEROBIC CAPACITY

    PubMed Central

    Bielec, G.; Makar, P.; Laskowski, R.

    2013-01-01

    Short duration repeated maximal efforts are often used in swimming training to improve lactate tolerance, which gives swimmers the ability to maintain a high work rate for a longer period of time. The aim of the study was to examine the kinematics of swimming and its relation to the changes in blood acid-base status and potassium level. Seven collegiate swimmers, with at least 6 years of training experience, volunteered to participate in the study. The test consisted of 8 x 25 m front crawl performed with maximum effort. The rest period between repetitions was set to five seconds. Blood samples were taken from the fingertip at rest, after warm-up and in the 3rd minute after completion of the test. The swimming was recorded with a video recorder, for later analysis of time, velocity and technique (stroke index). Based on the swimming velocity results, the obtained curve can be divided into rapid decrease of velocity and relatively stable velocities. The breaking point of repetition in swimming velocity was assumed as the swimming velocity threshold and it was highly correlated with the decrease of the blood acid-base status (pH r=0.82, BE r=0.87, HCO3 - r=0.76; p<0.05 in all cases). There was no correlation between stroke index or fatigue index and blood acid-base status. Analysis of the swimming speed in the 8 x 25 m test seems to be helpful in evaluation of lactate tolerance (anaerobic capacity) in collegiate swimmers. PMID:24744491

  6. Blood and urine acid-base status of premenopausal omnivorous and vegetarian women.

    PubMed

    Ball, D; Maughan, R J

    1997-11-01

    The effect of long-term differences in diet composition on whole-body acid-base status was examined in thirty-three young healthy females. The volunteers were recruited from two separate groups matched approximately for age, height and weight; one group regularly ate meat (omnivores; n 20) and one group did not (vegetarians; n 13). All subjects completed a 7 d weighed intake of food, and from their dietary records, total energy, carbohydrate (CHO), fat and protein content were estimated using computer-based food composition tables. During this week they reported to the laboratory on two occasions, following an overnight fast and separated by at least 48 h. Arterialized venous blood samples were obtained on each visit and these were analysed for blood acid-base status. Haemoglobin and packed cell volume, serum total cholesterol and HDL-cholesterol, serum albumin and total protein were also determined. Two 24 h urine collections were completed; the volume was recorded and samples were analysed for pH, titratable acid and Mg and Ca concentration. Total energy intake of the omnivores was greater (P = 0.0003) than that of the vegetarian group. Dietary intake of CHO (P = 0.024), fat (P = 0.0054) and protein (P = 0.0002) were higher in the omnivorous group than in the vegetarians. There were no differences between the two groups with respect to blood CO2 partial pressure, plasma HCO3- and blood base excess, but blood pH was slightly higher in the omnivores (P = 0.064). Measures of urine acid-base status suggested a lower pH in the omnivore group, but this difference was not statistically significant; a greater titratable acid output was observed with the omnivorous group compared with the vegetarians (48.9 (SE 20.3) v. 35.3 (SE 23.3) mEq/24h; P = 0.018). Although the dietary intake of Ca was not different between the two groups, urinary Ca excretion of the omnivores was significantly higher (3.87 (SD 1.34) v. 3.22 (SD 1.20) mmol/24 h) than that of the vegetarians (P = 0

  7. Effects of supplemental protein on acid-base status and calcium metabolism of nonlactating Jersey cows.

    PubMed

    Wang, C; Beede, D K

    1990-11-01

    The objective was to study effects of 11, 15, and 19% dietary CP on acid-base status, Ca balance, and metabolic responses to intravenous infusion of disodium EDTA. Dietary protein content was increased by supplementation of hydrolyzed feather meal and distillers dried grains with solubles to a concentrate combined with cottonseed hulls (40:60). Six nonlactating, nonpregnant multiparous Jersey cows (average 6.7 yr old) were used in two balanced 3 x 3 Latin squares with 24-d periods. Increasing supplemental CP decreased blood base excess, urinary titratable base, and net base excretion, but increased urinary ammonium excretion. Calcium excretion and balance were not affected by supplemental CP. Analysis to detect heterogeneity of regression showed that response of plasma EDTA-free Ca to EDTA infusion over time was not different among treatments. Increasing supplemental protein induced mild acidosis but did not affect Ca balance or responses to Ca removal from blood (via EDTA infusion) of non-lactating cows.

  8. Effects of inhibition gastric acid secretion on arterial acid-base status during digestion in the toad Bufo marinus.

    PubMed

    Andersen, Johnnie B; Andrade, Denis V; Wang, Tobias

    2003-07-01

    Digestion affects acid-base status, because the net transfer of HCl from the blood to the stomach lumen leads to an increase in HCO3(-) levels in both extra- and intracellular compartments. The increase in plasma [HCO3(-)], the alkaline tide, is particularly pronounced in amphibians and reptiles, but is not associated with an increased arterial pH, because of a concomitant rise in arterial PCO2 caused by a relative hypoventilation. In this study, we investigate whether the postprandial increase in PaCO2 of the toad Bufo marinus represents a compensatory response to the increased plasma [HCO3(-)] or a state-dependent change in the control of pulmonary ventilation. To this end, we successfully prevented the alkaline tide, by inhibiting gastric acid secretion with omeprazole, and compared the response to that of untreated toads determined in our laboratory during the same period. In addition, we used vascular infusions of bicarbonate to mimic the alkaline tide in fasting animals. Omeprazole did not affect blood gases, acid-base and haematological parameters in fasting toads, but abolished the postprandial increase in plasma [HCO3(-)] and the rise in arterial PCO2 that normally peaks 48 h into the digestive period. Vascular infusion of HCO3(-), that mimicked the postprandial rise in plasma [HCO3(-)], led to a progressive respiratory compensation of arterial pH through increased arterial PCO2. Thus, irrespective of whether the metabolic alkalosis is caused by gastric acid secretion in response to a meal or experimental infusion of bicarbonate, arterial pH is being maintained by an increased arterial PCO2. It seems, therefore, that the elevated PCO2, occuring during the postprandial period, constitutes of a regulated response to maintain pH rather than a state-dependent change in ventilatory control.

  9. Alterations in acid-base status and blood gas dynamics during progressive hyperkalaemia in neonatal calves.

    PubMed

    Singh, A; Randhawa, S S; Setia, M S

    1989-03-01

    Alterations in acid-base status and blood-gas dynamics were studied during induced progressive hyperkalaemia in neonatal calves. The hyperkalaemia was associated initially with respiratory alkalosis in arterial blood when plasma K+ was increased to 6.08 +/- 1.02 mmol litre-1. The rise of plasma K+ above 6.08 +/- 1.02 mmol litre-1 led to the development of metabolic acidosis in arterial and venous blood. There was partial respiratory compensation. Plasma K+ concentrations at or above 11.03 +/- 0.34 mmol litre-1 were associated with a decrease in arterial oxygen tension and arterial oxygen saturation. The oxygen extraction ratio was increased during hyperkalaemia.

  10. A physicochemical model of crystalloid infusion on acid-base status.

    PubMed

    Omron, Edward M; Omron, Rodney M

    2010-09-01

    The objective of this study is to develop a physicochemical model of the projected change in standard base excess (SBE) consequent to the infused volume of crystalloid solutions in common use. A clinical simulation of modeled acid-base and fluid compartment parameters was conducted in a 70-kg test participant at standard physiologic state: pH =7.40, partial pressure of carbon dioxide (PCO2) = 40 mm Hg, Henderson-Hasselbalch actual bicarbonate ([HCO3]HH) = 24.5 mEq/L, strong ion difference (SID) = 38.9 mEq/L, albumin = 4.40 g/dL, inorganic phosphate = 1.16 mmol/L, citrate total = 0.135 mmol/L, and SBE =0.1 mEq/L. Simulations of multiple, sequential crystalloid infusions up to 10 L were conducted of normal saline (SID = 0), lactated Ringer's (SID = 28), plasmalyte 148 (SID = 50), one-half normal saline þ 75 mEq/L sodium bicarbonate (NaHCO3; SID = 75), 0.15 mol/L NaHCO3 (SID = 150), and a hypothetical crystalloid solution whose SID = 24.5 mEq/L, respectively. Simulations were based on theoretical completion of steady-state equilibrium and PCO2 was fixed at 40 mm Hg to assess nonrespiratory acid-base effects. A crystalloid SID equivalent to standard state actual bicarbonate (24.5 mEq/L) results in a neutral metabolic acid-base status for infusions up to 10 L. The 5 study solutions exhibited curvilinear relationships between SBE and crystalloid infusion volume in liters. Solutions whose SID was greater than 24.5 mEq/L demonstrated a progressive metabolic alkalosis and less, a progressive metabolic acidosis. In a human model system, the effects of crystalloid infusion on SBE are a function of the crystalloid and plasma SID, volume infused, and nonvolatile plasma weak acid changes. A projection of the impact of a unit volume of various isotonic crystalloid solutions on SBE is presented. The model's validation, applications, and limitations are examined.

  11. Clinical assessment of acid-base status. Strong ion difference theory.

    PubMed

    Constable, P D

    1999-11-01

    The traditional approach to evaluating acid-base balance uses the Henderson-Hasselbalch equation to categorize four primary acid-base disturbances: respiratory acidosis (increased PCO2), respiratory alkalosis (decreased PCO2), metabolic acidosis (decreased extracellular base excess), or metabolic alkalosis (increased extracellular base excess). The anion gap is calculated to detect the presence of unidentified anions in plasma. This approach works well clinically and is recommended for use whenever serum total protein, albumin, and phosphate concentrations are approximately normal; however, when their concentrations are markedly abnormal, the Henderson-Hasselbalch equation frequently provides erroneous conclusions as to the cause of an acid-base disturbance. Moreover, the Henderson-Hasselbalch approach is more descriptive than mechanistic. The new approach to evaluating acid-base balance uses the simplified strong ion model to categorize eight primary acid-base disturbances: respiratory acidosis (increased PCO2), respiratory alkalosis (decreased PCO2), strong ion acidosis (decreased [SID+]) or strong ion alkalosis (increased [SID+]), nonvolatile buffer ion acidosis (increased [ATOT]) or nonvolatile buffer ion alkalosis (decreased [ATOT]), and temperature acidosis (increased body temperature) or temperature alkalosis (decreased body temperature). The strong ion gap is calculated to detect the presence of unidentified anions in plasma. This simplified strong ion approach works well clinically and is recommended for use whenever serum total protein, albumin, and phosphate concentrations are markedly abnormal. The simplified strong ion approach is mechanistic and is therefore well suited for describing the cause of any acid-base disturbance. The new approach should therefore be valuable in a clinical setting and in research studies investigating acid-base balance. The presence of unmeasured strong ions in plasma or serum (such as lactate, ketoacids, and uremic anions

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

    SciTech Connect

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

    1990-09-01

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

  13. Monitoring of acid-base status of workers at a methyl methacrylate and polymethyl methacrylate production plant in Bulgaria.

    PubMed

    Prakova, Gospodinka R

    2003-01-01

    This study was carried out on 104 workers at three work operations and a control (nonproduction) area, within a methyl methacrylate (MMA)/polymethyl methacrylate (PMMA) production facility in Bulgaria. Airborne monitoring was conducted over a 10-year period for MMA and the reactant chemicals methanol and acetone cyanhydrine at the MMA operation, and MMA was monitored at the PMMA operation. Acid-base status of the workers was evaluated using traditional criteria (pH, pCO(2), pO(2), and HCO(3) in plasma). Data from retrospective monitoring of air levels of the chemicals were compared with the acid-base status of workers at the plant. In some cases air concentrations exceeded the threshold limit value, with the highest percentage of overexposure occurring with airborne MMA in the PMMA production operation. Acid-base disruption indicated by reductions in plasma pH and HCO(3) was found for all groups except the control population. The highest percentage reduction was associated with PMMA production workers. Additionally, respiratory acidosis, indicated by increased pCO(2), was noted in the MMA production and maintenance groups, implying that the response to MMA exposure may involve both the metabolic and respiratory acidosis component. This study was unique in that the combined exposure to MMA and the precursor chemical (methanol) were shown to produce the same effects in workers. It is suggested that when combined exposure occurs, disruption of acid-base status may occur. Enforcement of PPM requirements for coveralls and gloves should prevent skin contamination. Additionally, improvement of equipment in MMA and PMMA production areas is recommended: (1) automation of some manual operations; (2) use of respiratory protection during equipment cleaning; and (3) installation of local ventilation when applicable.

  14. Stream chemistry in the eastern United States. 1. Synoptic survey design, acid-base status, and regional patterns

    SciTech Connect

    Kaufmann, P.R.; Herlihy, A.T.; Mitch, M.E.; Messer, J.J. ); Overton, W.S. )

    1991-04-01

    To assess the regional acid-base status of streams in the mid-Atlantic and southern US, spring base flow chemistry was surveyed in a probability sample of 500 stream reaches representing a population of 64,300 reaches (224,000 km). Approximately half of the streams had acid-neutralizing capacity (ANC) {le} 200 {mu}eq L{sup {minus}1}. Acidic (ANC {le} 0) streams were located in the highlands of the Mid-Atlantic region (southern New York to southern Virginia, 2,330 km), in coastal lowlands of the Mid-Atlantic (2,600 km), and in Florida (462 km). Acidic streams were rare (less than 1%) in the highlands of the Southeast. Inorganic monomeric aluminum (Al{sub im}) concentrations were highest in acidic streams of the Mid-Atlantic Highlands where over 70% of the acidic streams had Al{sub im} greater than 100 {mu}g L{sup {minus}1}, a concentration above which deleterious biological effects have frequently been reported. Dissolved organic carbon concentrations were much higher in lowland coastal streams, compared with inland streams. The authors data supports a hypothesis that atmospheric sources and watershed retention control regional patterns in streamwater sulfate concentrations. Most stream watersheds retain the vast majority of the total nitrogen loading from wet deposition. The data suggest, however, that some deposition nitrogen may be reaching streams in the Northern Appalachians.

  15. Clinical assessment of acid-base status: comparison of the Henderson-Hasselbalch and strong ion approaches.

    PubMed

    Constable, Peter D.

    2000-01-01

    The traditional approach for clinically assessing acid-base status uses the Henderson-Hasselbalch equation to categorize 4 primary acid-base disturbances: respiratory acidosis (increased PCO2), respiratory alkalosis (decreased PCO2), metabolic acidosis (decreased extracellular base excess or actual HCO3- concentration), and metabolic alkalosis (increased extracellular base excess or actual HCO3- concentration). The anion gap is calculated to detect unidentified anions in plasma. This approach works well clinically and is recommended for use whenever serum total protein, albumin, and phosphate concentrations are approximately normal. However, because the Henderson-Hasselbalch approach is more descriptive than mechanistic, when these concentrations are markedly abnormal the Henderson-Hasselbalch equation frequently provides erroneous information as to the cause of an acid-base disturbance. The new quantitive physicochemical approach to evaluating acid-base balance uses the simplified strong ion model to categorize 6 primary acid-base disturbances: respiratory acidosis (increased PCO2), respiratory alkalosis (decreased PCO2), strong ion acidosis (decreased strong ion difference), strong ion alkalosis (increased strong ion difference), nonvolatile buffer ion acidosis (increased plasma concentrations of albumin, globulins, or phosphate), and nonvolatile buffer ion alkalosis (decreased plasma concentrations of albumin, globulins, or phosphate). The strong ion gap is calculated to detect unidentified anions in plasma. The simplified strong ion approach works well clinically and is recommended for use whenever serum total protein, albumin, or phosphate concentrations are markedly abnormal. The simplified strong ion approach is mechanistic and is therefore well suited for describing the cause of any acid-base disturbance.

  16. Contemporary trends in the acid-base status of two acid-sensitive streams in Western Maryland

    SciTech Connect

    Keith N. Eshleman; Kathleen M. Kline; Raymond P. Morgan II; Nancy M. Castro; Timothy L. Negley

    2008-01-01

    Recovery of streamwater acid neutralizing capacity (ANC) resulting from declines in regional acid deposition was examined using contemporary (1990-2005) data from two long-term monitoring stations located on the Appalachian Plateau in western Maryland, U.S. Two computational methods were used to estimate daily, monthly, and annual fluxes and discharge-weighted concentrations of ANC, sulfate, nitrate, and base cations over the period of record, and two statistical methods were used to evaluate long-term trends in fluxes and concentrations. The methods used to estimate concentrations, as well as the statistical techniques, produced very similar results, underlining the robustness of the identified trends. We found clear evidence that streamwater sulfate concentrations have declined at an average rate of about 3 {mu}eq L{sup -1} yr{sup -1} at the two sites due to a 34% reduction in wet atmospheric sulfur deposition. Trends in nitrate concentrations appear to be related to other watershed factors, especially forest disturbance. The best evidence of recovery is based on a doubling of ANC (from 21 to 42 {mu}eq L{sup -1}) at the more acid-sensitive site over the 16-year period. A slowing, or possible reversal, in the sulfate, nitrate, and SBC trends is evident in our data and may portend a decline in the rate of or end to further recovery. 33 refs., 4 figs., 1 tab.

  17. Contemporary Trends in the Acid-Base Status of the Two Acid-Sensitive Streams in Western Maryland

    NASA Technical Reports Server (NTRS)

    Eshleman, Keith N.; Kline, Kathleen M.; Morgan, Raymond P., II; Castro, Nancy M.; Negley, Timothy L.

    2008-01-01

    Recovery of streamwater acid neutralizing capacity (ANC) resulting from declines in regional acid deposition was examined using contemporary (1990-2005) data from two long-term monitoring stations located on the Appalachian Plateau in western Maryland, U.S. Two computational methods were used to estimate daily, monthly, and annual fluxes and discharge-weighted concentrations of ANC, sulfate, nitrate, and base cations over the period of record, and two statistical methods were used to evaluate long-term trends in fluxes and concentrations. The methods used to estimate concentrations, as well as the, statistical techniques, produced very similar results, underlining the robustness of the identified trends. We found clear evidence that streamwater sulfate concentrations have declined at an average rate of about 3 (microns)eq L(exp -1) yr(exp -1) at the two sites due to a 34% reduction in wet atmospheric sulfur deposition. Trends in nitrate concentrations appear to be related to other watershed factors, especially forest disturbance. The best evidence of recovery is based on a doubling of ANC (from 21 to 42 (microns)eq L(exp -1) at the more acid-sensitive site over the 16-year period. A slowing, or possible reversal, in the sulfate, nitrate, and SBC trends is evident in our data and may portend a decline in the rate of--or end to--further recovery.

  18. Contemporary trends in the acid-base status of two acid-sensitive streams in western Maryland.

    PubMed

    Eshleman, Keith N; Kline, Kathleen M; Morgan, Raymond P; Castro, Nancy M; Negley, Timothy L

    2008-01-01

    Recovery of streamwater acid neutralizing capacity (ANC) resulting from declines in regional acid deposition was examined using contemporary (1990-2005) data from two long-term monitoring stations located on the Appalachian Plateau in western Maryland, U.S. Two computational methods were used to estimate daily, monthly, and annual fluxes and discharge-weighted concentrations of ANC, sulfate, nitrate, and base cations over the period of record, and two statistical methods were used to evaluate long-term trends in fluxes and concentrations. The methods used to estimate concentrations, as well as the statistical techniques, produced very similar results, underlining the robustness of the identified trends. We found clear evidence that streamwater sulfate concentrations have declined at an average rate of about 3 microeq L(-1) yr(-1) at the two sites due to a 34% reduction in wet atmospheric sulfur deposition. Trends in nitrate concentrations appear to be related to other watershed factors, especially forest disturbance. The best evidence of recovery is based on a doubling of ANC (from 21 to 42 microeq L(-1)) at the more acid-sensitive site over the 16-year period. A slowing, or possible reversal, in the sulfate, nitrate, and SBC trends is evident in our data and may portend a decline in the rate of--or end to--further recovery.

  19. Contemporary trends in the acid-base status of two acid-sensitive streams in western Maryland.

    PubMed

    Eshleman, Keith N; Kline, Kathleen M; Morgan, Raymond P; Castro, Nancy M; Negley, Timothy L

    2008-01-01

    Recovery of streamwater acid neutralizing capacity (ANC) resulting from declines in regional acid deposition was examined using contemporary (1990-2005) data from two long-term monitoring stations located on the Appalachian Plateau in western Maryland, U.S. Two computational methods were used to estimate daily, monthly, and annual fluxes and discharge-weighted concentrations of ANC, sulfate, nitrate, and base cations over the period of record, and two statistical methods were used to evaluate long-term trends in fluxes and concentrations. The methods used to estimate concentrations, as well as the statistical techniques, produced very similar results, underlining the robustness of the identified trends. We found clear evidence that streamwater sulfate concentrations have declined at an average rate of about 3 microeq L(-1) yr(-1) at the two sites due to a 34% reduction in wet atmospheric sulfur deposition. Trends in nitrate concentrations appear to be related to other watershed factors, especially forest disturbance. The best evidence of recovery is based on a doubling of ANC (from 21 to 42 microeq L(-1)) at the more acid-sensitive site over the 16-year period. A slowing, or possible reversal, in the sulfate, nitrate, and SBC trends is evident in our data and may portend a decline in the rate of--or end to--further recovery. PMID:18350875

  20. The oxidative stress, antioxidant profile and acid-base status in preterm and term canine neonates.

    PubMed

    Vannucchi, C I; Kishi, D; Regazzi, F M; Silva, L C G; Veiga, G A L; Angrimani, D S R; Lucio, C F; Nichi, M

    2015-04-01

    During the initiation of neonatal pulmonary respiration, there is an exponential increase in reactive oxygen species that must be scavenged by antioxidant defences. However, neonate and preterm newborns are known to possess immature antioxidant mechanisms to neutralize these toxic effects. The purposes of this study were to compare the development of antioxidant system between preterm and term canine neonates and to evaluate the magnitude of acid-base balance during the initial 4 h of life. A prospective study was conducted involving 18 neonatal puppies assigned to Term Group (63 days of gestation; n = 5), Preterm-57 Group (57 days of gestation; n = 8) and Preterm-55 Group (55 days of gestation; n = 5). Neonates were physically examined through Apgar score and venous haemogasometry within 5 min, 2 and 4 h after birth. No difference on amniotic fluid and serum superoxide dismutase (SOD), glutathione peroxidase (GPx) and the marker of oxidative stress (thiobarbituric acid reactive substances; TBARS) was verified. Irrespective of prematurity, all neonates presented low vitality, hypothermia, acidosis, hypoxaemia and hypercapnia at birth. However, term puppies clinically evolved more rapidly than preterm newborns. During the course of the study, premature neonates presented more severe complications, such as prolonged hypoxaemia and even death. In conclusion, premature puppies have no signs of immature enzymatic mechanisms for controlling oxidative stress, although SOD and GPx may participate in achieving acid-base balance. Aside from initial unremarkable symptoms, premature puppies should be carefully followed up, as they are at high risk of succumbing to odds of prematurity.

  1. Alterations in the systemic acid-base status and blood gas dynamics during progressive hypocalcaemia in cow calves.

    PubMed

    Setia, M S; Singh, A; Kahlon, R S; Randhawa, S S

    1996-04-01

    Hypocalcaemia, induced in cow calves by slow infusion of Na2EDTA for 6 hr, led to biphasic changes in acid-base status. Decrease in ionized plasma Ca2+ concentration upto 0.82 +/- 0.06 mmole 1(-1) was associated with metabolic alkalosis. Further decrease in ionized plasma Ca2+ concentration (0.61 +/- 0.09 mmole 1(-1)) led to metabolic acidosis, superimposed by a respiratory component. There was significant decrease in oxygen tension and saturation of arterial blood as well as impaired uptake of oxygen by peripheral tissues and pulmonary blood.

  2. [Acid-base status in newborn calves during the first days of life considering different states of vitality].

    PubMed

    Herfen, K; Bostedt, H

    1999-06-01

    The aim of this study is to describe the differentiations of the acid-base status in bovine neonates during the first 96 hours of life. Due to the short intervals in the taking of blood samples, noticeable fluctuations in the acid-base status during the first minutes and hours of life of newborn calves were documented. Altogether, 25 matures and eutrophe calves of the DSB, DRB and DFV breeds were provided by the clinic for this study. Apart from an immediate post natum clinical interpretation of the vital signs in the neonates-using the APGAR-score-the pH value, current Base Excess and the CO2 pressure were simultaneously ascertained. Further continuous evaluation of the acid-base status was subsequently followed in the first phase of adaptation. For that alone, twelve blood samples were taken from the vena jugularis within the first 60 minutes after parturition. Until the end of the examination period on the fourth day of life, the tests amounted to 26 measurements altogether per experimentee. Due to the concrete results ascertained from the initial clinical and laboratory observations, the experimentees could be divided into distinct classes of vitality. The acid-base status of all the calves deteriorated during the first minutes of life, indicating that the pH value and Base Excess fall clearly under the initial level in all aspects of vitality directly post natum. On average the minimum pH values are reached between the third and 15th minute of life and remain between 0.019 and 0.096 below the initial values during this period. A varying rapid increase of the pH value follows, together with a balancing out of the Base difference. Despite isolated individual variations as the acid-base status develops, the lowering of the pH values in the first minutes of life is assessed as being a normal biological phenomenon. Deviations from this occur rarely (8%) and do not conform to the norm. The pH value stabilization in connection with this crucial early postnatal phase

  3. Determination of the acid-base status in 50 horses admitted with colic between December 1998 and May 1999.

    PubMed Central

    Nappert, G; Johnson, P J

    2001-01-01

    The purpose of the present study was to investigate the acid-base status and the concentration of organic acids in horses with colic caused by various disorders. Blood samples were collected from 50 horses with colic and from 20 controls. No intravenous fluids had been given prior to sample collection. Identified causes of colic included gastric ulceration, small intestinal volvulus, cecal intussusception, cecal rupture, colonic impaction, left dorsal colon displacement, right dorsal colon displacement, colonic volvulus, colitis, peritonitis, and uterine torsion. Thirty-seven horses recovered from treatment of colic, 8 horses were euthanized, and 5 died. Most cases were not in severe metabolic acidosis. In previous studies, most horses presented for diagnosis and treatment of colic were in metabolic acidosis and in shock. PMID:11565369

  4. Effect of dietary potassium and anionic salts on acid-base and mineral status in periparturient cows.

    PubMed

    Rérat, M; Schlegel, P

    2014-06-01

    Dry cow diets based on grassland forage from intensive production contain high amounts of K and could be responsible for a reduced ability to maintain Ca homoeostasis. The aim of this study was to determine whether a moderate anionic salt supplementation to a forage-based pre-calving diet with varying native K content affects the mineral and acid-base status in transition cows. Twenty-four dry and pregnant Holstein cows, without antecedent episodes of clinical hypocalcemia, were assigned to two diets during the last 4 weeks before estimated calving date. Twelve cows were fed a hay-based diet low in K (18 g K/kg DM), and 12, a hay-based diet high in K (35 g K/kg DM). Within each diet, six cows received anionic salts during the last 2 weeks before the estimated calving day. After calving, all cows received the high K diet ad libitum. Blood samples were taken daily from day 11 pre-partum to day 5 post-partum. Urine samples were taken on days 7 and 2 pre-partum and on day 2 post-partum. The anionic salt did not alter feed intake during the pre-partum period. Serum Ca was not influenced by the dietary treatments. Feeding pre-partum diets with low K concentrations induced a reduced metabolic alkalotic charge, as indicated by reduced pre-partum urinary base-acid quotient. Transition cows fed the low K diet including anionic salts induced a mild metabolic acidosis before calving, as indicated by higher urinary Ca, lower urinary pH and net acid-base excretion. Although serum Ca during the post-partum period was not affected by dietary treatment, feeding a low K diet moderately supplemented with anionic salts to reach a dietary cation-anion difference close to zero permitted to obtain a metabolic response in periparturient cows without altering the dry matter intake.

  5. Effects of anaesthesia on blood gases, acid-base status and ions in the toad Bufo marinus.

    PubMed

    Andersen, Johnnie Bremholm; Wang, Tobias

    2002-03-01

    It is common practice to chronically implant catheters for subsequent blood sampling from conscious and undisturbed animals. This method reduces stress associated with blood sampling, but anaesthesia per se can also be a source of stress in animals. Therefore, it is imperative to evaluate the time required for physiological parameters (e.g. blood gases, acid-base status, plasma ions, heart rate and blood pressure) to stabilise following surgery. Here, we report physiological parameters during and after anaesthesia in the toad Bufo marinus. For anaesthesia, toads were immersed in benzocaine (1 g l(-1)) for 15 min or until the corneal reflex disappeared, and the femoral artery was cannulated. A 1-ml blood sample was taken immediately after surgery and subsequently after 2, 5, 24 and 48 h. Breathing ceased during anaesthesia, which resulted in arterial Po(2) values below 30 mmHg, and respiratory acidosis developed, with arterial Pco(2) levels reaching 19.5+/-2 mmHg and pH 7.64+/-0.04. The animals resumed pulmonary ventilation shortly after the operation, and oxygen levels increased to a constant level within 2 h. Acid--base status, however, did not stabilise until 24 h after anaesthesia. Haematocrit doubled immediately after cannulation (26+/-1%), but reached a constant level of 13% within 24 h. Blood pressure and heart rate were elevated for the first 5 h, but decreased after 24 h to a constant level of approximately 30 cm H2O and 35 beats min(-1), respectively. There were no changes following anaesthesia in mean cellular haemoglobin concentration, [K+], [Cl-], [Na+], [lactate] or osmolarity. Toads fully recovered from anaesthesia after 24 h.

  6. Understanding Acid Base Disorders.

    PubMed

    Gomez, Hernando; Kellum, John A

    2015-10-01

    The concentration of hydrogen ions is regulated in biologic solutions. There are currently 3 recognized approaches to assess changes in acid base status. First is the traditional Henderson-Hasselbalch approach, also called the physiologic approach, which uses the relationship between HCO3(-) and Pco2; the second is the standard base excess approach based on the Van Slyke equation. The third approach is the quantitative or Stewart approach, which uses the strong ion difference and the total weak acids. This article explores the origins of the current concepts framing the existing methods to analyze acid base balance.

  7. Changes in acid-base status of marathon runners during an incremental field test. Relationship to mean competitive marathon velocity.

    PubMed

    Zoladz, J A; Sargeant, A J; Emmerich, J; Stoklosa, J; Zychowski, A

    1993-01-01

    Four top-class runners who regularly performed marathon and long-distance races participated in this study. They performed a graded field test on an artificial running track within a few weeks of a competitive marathon. The test consisted of five separate bouts of running. Each period lasted 6 min with an intervening 2-min rest bout during which arterialized capillary blood samples were taken. Blood was analysed for pH, partial pressure of oxygen and carbon dioxide (PO2 and PCO2) and lactate concentration ([la-]b). The values of base excess (BE) and bicarbonate concentration ([HCO3-]) were calculated. The exercise intensity during the test was regulated by the runners themselves. The subjects were asked to perform the first bout of running at a constant heart rate fc which was 50 beats.min-1 below their own maximal fc. Every subsequent bout, each of which lasted 6 min, was performed with an increment of 10 beats.min-1 as the target fc. Thus the last, the fifth run, was planned to be performed with fc amounting to 10 beats.min-1 less than their maximal fc. The results from these runners showed that the blood pH changed very little in the bouts performed at a running speed below 100% of mean marathon velocity (nu m). However, once nu m was exceeded, there were marked changes in acid-base status. In the bouts performed at a velocity above the nu m there was a marked increase in [la-]b and a significant decrease in pH, [HCO3-], BE and pCO2. The average marathon velocity (nu m) was 18.46 (SD 0.32) km.h-1.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8375370

  8. Could the acid-base status of Antarctic sea urchins indicate a better-than-expected resilience to near-future ocean acidification?

    PubMed

    Collard, Marie; De Ridder, Chantal; David, Bruno; Dehairs, Frank; Dubois, Philippe

    2015-02-01

    Increasing atmospheric carbon dioxide concentration alters the chemistry of the oceans towards more acidic conditions. Polar oceans are particularly affected due to their low temperature, low carbonate content and mixing patterns, for instance upwellings. Calcifying organisms are expected to be highly impacted by the decrease in the oceans' pH and carbonate ions concentration. In particular, sea urchins, members of the phylum Echinodermata, are hypothesized to be at risk due to their high-magnesium calcite skeleton. However, tolerance to ocean acidification in metazoans is first linked to acid-base regulation capacities of the extracellular fluids. No information on this is available to date for Antarctic echinoderms and inference from temperate and tropical studies needs support. In this study, we investigated the acid-base status of 9 species of sea urchins (3 cidaroids, 2 regular euechinoids and 4 irregular echinoids). It appears that Antarctic regular euechinoids seem equipped with similar acid-base regulation systems as tropical and temperate regular euechinoids but could rely on more passive ion transfer systems, minimizing energy requirements. Cidaroids have an acid-base status similar to that of tropical cidaroids. Therefore Antarctic cidaroids will most probably not be affected by decreasing seawater pH, the pH drop linked to ocean acidification being negligible in comparison of the naturally low pH of the coelomic fluid. Irregular echinoids might not suffer from reduced seawater pH if acidosis of the coelomic fluid pH does not occur but more data on their acid-base regulation are needed. Combining these results with the resilience of Antarctic sea urchin larvae strongly suggests that these organisms might not be the expected victims of ocean acidification. However, data on the impact of other global stressors such as temperature and of the combination of the different stressors needs to be acquired to assess the sensitivity of these organisms to global

  9. Long-term effects of dietary anion-cation balance on acid-base status and bone morphology in reproducing ewes.

    PubMed

    Espino, L; Guerrero, F; Suarez, M L; Santamarina, G; Goicoa, A; Fidalgo, L E

    2003-12-01

    The beneficial effects of anionic salts on calcium metabolism have been shown by supplementing rations with such salts during the last 3 weeks of pre-partum. However, there are few reports on the effects of anionic salts supplementation for periods of 4 weeks or longer on acid-base status, mineral metabolism and bone morphology. This study was conducted to evaluate the effects of the long-term dietary supplementation of anionic salts on the acid-base status, plasma minerals concentrations and bone morphology in sheep. Twenty-seven twin-bearing sheep were assigned to two experimental groups and a control group, depending on dietary cation-anion difference (DCAD) (+272.6, -88.9 and + 164.5 mEq/kg DM, respectively). Sheep assigned to each dietary treatment received their respective rations beginning 6 weeks prepartum and continuing until 12 days post-partum. Diets containing anionic salts induced a mild metabolic hyperchloraemic acidosis from 1 week pre-partum to 2 days post-partum that was completely compensated by non-respiratory mechanisms. These changes on acid-base status were accompanied by an increase of plasma ionized calcium levels. Plasma total calcium, phosphorus and magnesium concentrations were not affected by dietary treatment. Parathyroid hormone concentrations were related to the concentration of ionized calcium of plasma and were higher in sheep fed the cationic diet. Plasma osteocalcin levels were increased in sheep fed the anionic diet and cortical bone remodelling occurred in all the animals during late pregnancy in light and electron microscopy observation, but was particularly evident in the sheep fed the anionic diet. Bone turnover might be stimulated because of the role of the bone in buffering systemic acidosis. The data suggest that anionic salts ameliorated calcium metabolism around parturition by increasing bone resorption and the concentration of ionised calcium in plasma, possibly mediated by a mild hyperchloraemic metabolic acidosis

  10. Value of plasma chloride concentration and acid-base status in the differential diagnosis of hyperpara-thyroidism from other causes of hypercalcaemia

    PubMed Central

    Wills, M. R.

    1971-01-01

    A study is reported of the estimation of plasma chloride concentration and acid-base status in the differentiation of primary hyperparathyroidism from all other causes of hypercalcaemia. In the two groups of patients studied, all of whom had hypercalcaemia, there was complete separation between the two groups on the basis of plasma chloride concentration and acid-base status. In 16 patients with primary hyperparathyroidism the increase in plasma chloride concentration and associated metabolic acidosis could have been accounted for by the known renal tubular effects of parathyroid hormone. In 13 patients with hypercalcaemia due to various other causes the decrease in plasma chloride concentration and associated metabolic alkalosis could be accounted for either by the known effects of an excess of calcium-ion on the renal tubules, or perhaps by suppression of endogenous parathyroid hormone secretion. In patients with hypercalcaemia and hypophosphataemia of `pseudohyperparathyroidism' associated with non-endocrine tumours it is postulated that the low plasma chloride concentrations and metabolic alkalosis found in these patients were due either to a differing biological activity of the parathyroid-hormone-like polypeptide secreted by the tumour cells, or possibly to simultaneous secretion by these cells of an ACTH-like polypeptide. PMID:5573436

  11. Acid-Base and Electrolyte Status during Normovolemic Hemodilution with Succinylated Gelatin or HES-Containing Volume Replacement Solutions in Rats

    PubMed Central

    Teloh, Johanna K.; Ferenz, Katja B.; Petrat, Frank; Mayer, Christian; de Groot, Herbert

    2013-01-01

    Background In the past, several studies have compared different colloidal replacement solutions, whereby the focus was usually on the respective colloid. We therefore systematically studied the influence of the carrier solution’s composition of five approved colloidal volume replacement solutions (Gelafundin, Gelafusal, Geloplasma, Voluven and Volulyte) on acid-base as well as electrolyte status during and following acute severe normovolemic hemodilution. The solutions differed in the colloid used (succinylated gelatin vs. HES) and in the presence and concentration of metabolizable anions as well as in their electrolyte composition. Methods Anesthetized Wistar rats were subjected to a stepwise normovolemic hemodilution with one of the solutions until a final hematocrit of 10%. Subsequent to dilution (162 min), animals were observed for an additional period (150 min). During dilution and observation time blood gas analyses were performed eight times in total. Additionally, in the Voluven and Volulyte groups as well as in 6 Gelafundin animals, electrolyte concentrations, glucose, pH and succinylated gelatin were measured in urine and histopathological evaluation of the kidney was performed. Results All animals survived without any indications of injury. Although the employed solutions differed in their respective composition, comparable results in all plasma acid-base and electrolyte parameters studied were obtained. Plasma pH increased from approximately 7.28 to 7.39, the plasma K+ concentration decreased from circa 5.20 mM to 4.80-3.90 mM and the plasma Cl− concentration rose from approximately 105 mM to 111–120 mM. Urinary analysis revealed increased excretion of K+, H+ and Cl−. Conclusions The present data suggest that the carrier solution’s composition with regard to metabolizable anions as well as K+, Ca2+ only has a minor impact on acid-base and electrolyte status after application of succinylated gelatin or HES-containing colloidal volume

  12. [Apgar status, blood gases and acid base balance of neonates after caesarean sections, using either thiopentone or ketamine for induction of anaesthesia (author's transl)].

    PubMed

    Traub, E; Knoche, E; Dick, W; Völschow, E

    1977-04-01

    Apgar status and acid base balance of 206 neonates, delivered by caesarean section under general anaesthesia, were investigated in order to compare the possible effects of either thiopentone- or ketamine-induction on the postpartum adaption. Several other criteria were recorded also, for instance, a possible neonatal asphyxia, the induction-delivery-interval, the maternal age, the administration of other than anaesthetic drugs etc. There were not correlations between the Apgar status and the induction-delivery interval in either groups. The number of neonates within the 3 Apgar-classes, and the asphyxiated neonates, were equally distributed in the thiopentone- and ketamine-groups. There was no correlation between maternal ages and either the thiopentone- or ketamin-babies, but a marked correlation with the number of depressed newborns. Those neonates, who were suspected to be hypoxic before anaesthesia showed a more depressed post-partum respiration after thiopentone- than after ketamine-induction. On the other hand it seems to be that neonatal respiration and total Apgar status was more depressed if the "ketamin mothers" were treated with sedatives, hypnotics and/or analgesics before caesarean section. The blood gas values and the acid base parameters did not show a statistically significant difference between the pH of the thiopentone- and the ketamine-neonates. These differences can be explained as the combination of the nonsignificant changes in PCO2 and standard-bicarbonate values. As far as can be judged from the above mentioned criteria it may be deduced that ketamine or thiopentone can equally well be used for inducation of anaesthesia for caesarean section.

  13. Effects of supplemental potassium and sodium chloride salts on ruminal turnover rates, acid-base and mineral status of lactating dairy cows during heat stress.

    PubMed

    Schneider, P L; Beede, D K; Wilcox, C J

    1988-01-01

    Effects of added dietary sodium and potassium chloride salts on ruminal turnover rates, acid-base balance and mineral status of lactating dairy cows experiencing a nycterohemeral cycle of heat stress were examined. Black globe-humidity index in the chambers averaged 94 during the daytime and 68 during the nighttime. Four ruminally cannulated multiparous Holstein cows in mid-lactation were confined in climatic chambers for a single-reversal experiment consisting of two 17-d periods. To the basal diet (50% corn silage: 50% concentrate, which contained .97% potassium, .19% sodium and .20% chloride), 1.25% sodium chloride plus 1.85% potassium chloride were added, making the high mineral treatment (1.93% potassium, 68% sodium and 1.85% chloride). Liquid dilution rates from the rumen were measured by chromium-ethylenediaminetetraacetate disappearance. Turnover rates of solids were determined by appearance of ytterbium in feces. Ruminal contents, arterial blood and urine were collected hourly for 26 h. Grab samples of feces were sampled over 6 d. Dry matter intakes and milk yields were not affected by the diets (averaging 17.8 and 21.1 kg/d, respectively). Cows fed the high mineral diet drank 17% more water (P less than .01). Tests for homogeneity of regression were utilized to compare chromium disappearance and ytterbium appearance data, which were best described by second-order polynomial functions. Increased ruminal chromium disappearance (P less than .01) and decreased total volatile fatty acid concentrations (P less than .01) suggested faster liquid dilution rates with high mineral diet, but turnover rates of solids were not affected. Urinary potassium secretion compensated for the high potassium content of the high mineral diet without an alkalogenic effect on acid-base status. Lower urine pH and higher urine ammonium concentrations during cool hours suggested that the high chloride content of the high mineral diet had an acidogenic effect. The results are

  14. Comparison of three strong ion models used for quantifying the acid-base status of human plasma with special emphasis on the plasma weak acids.

    PubMed

    Anstey, Chris M

    2005-06-01

    Currently, three strong ion models exist for the determination of plasma pH. Mathematically, they vary in their treatment of weak acids, and this study was designed to determine whether any significant differences exist in the simulated performance of these models. The models were subjected to a "metabolic" stress either in the form of variable strong ion difference and fixed weak acid effect, or vice versa, and compared over the range 25 < or = Pco(2) < or = 135 Torr. The predictive equations for each model were iteratively solved for pH at each Pco(2) step, and the results were plotted as a series of log(Pco(2))-pH titration curves. The results were analyzed for linearity by using ordinary least squares regression and for collinearity by using correlation. In every case, the results revealed a linear relationship between log(Pco(2)) and pH over the range 6.8 < or = pH < or = 7.8, and no significant difference between the curve predictions under metabolic stress. The curves were statistically collinear. Ultimately, their clinical utility will be determined both by acceptance of the strong ion framework for describing acid-base physiology and by the ease of measurement of the independent model parameters.

  15. Oxygen affinity of haemoglobin and red cell acid-base status in patients with severe chronic obstructive lung disease.

    PubMed

    Huckauf, H; Schäfer, J H; Kollo, D

    1976-01-01

    The oxygen affinity of hemoglobin and the factors determining the position of the oxygen dissociation curve were investigated in twenty-five patients with severe chronic obstructive lung disease. Patients have been separated into three groups: group I showed a normal or mild decrease of PaO2, group II a moderate fall in arterial oxygen pressure, and group III a severe hypoxia with balanced acid-base equilibrium and hypercapnia. Blood hemoglobin exhibited a significant increase in all groups, indicating an improved oxygen transport. In most patients a leftward shifting of the oxygen dissociation curve occurred. It is discussed that the tendency to left shifting is based upon alkalosis inside the red cells, evidently demonstrated in all groups studied. 2,3-diphosphoglycerate showed no close relation to evaluated oxygen affinity of hemoglobin. The evidence for an increased oxygen affinity may reveal a further compensatory mechanism in oxygen transport in patients with pulmonary disorders. Additionally the alkalosis inside the cells may counterbalance too great a right shifting of oxygen dissociation curve in vivo when severe hypoxia and hypercapnia occur. PMID:13884

  16. Blood gas tensions, acid-base status, heart rates, and venous profiles in exercising horses with laryngeal hemiplegia before and after corrective surgery.

    PubMed

    Tate, L P; Corbett, W T; Bishop, B J; Foreman, J H

    1993-01-01

    The physiologic effects of exercise were studied in four horses with complete laryngeal hemiplegia. Right carotid arteries were surgically elevated to a subcutaneous position for percutaneous catheterization. Each horse was fitted with a device designed to obtain multiple arterial samples while the horse was exercised over a 1.6-km course. After each horse completed 10 test gallops, the laryngeal hemiplegia was treated using a laryngeal prothesis and ventriculectomy. The horses were then reconditioned, and the exercise test and sampling were repeated. Horses with laryngeal hemiplegia became acidotic, hypoxic, and hypercapnic compared to normal horses. Surgical treatment improved blood gas and acid-base status, but the values were not equivalent to those in normal horses similarly tested.

  17. Validation of the i-STAT system for the analysis of blood gases and acid-base status in juvenile sandbar shark (Carcharhinus plumbeus).

    PubMed

    Harter, T S; Morrison, P R; Mandelman, J W; Rummer, J L; Farrell, A P; Brill, R W; Brauner, C J

    2015-01-01

    Accurate measurements of blood gases and acid-base status require an array of sophisticated laboratory equipment that is typically not available during field research; such is the case for many studies on the stress physiology, ecology and conservation of elasmobranch fish species. Consequently, researchers have adopted portable clinical analysers that were developed for the analysis of human blood characteristics, but often without thoroughly validating these systems for their use on fish. The aim of our study was to test the suitability of the i-STAT system, the most commonly used portable clinical analyser in studies on fish, for analysing blood gases and acid-base status in elasmobranchs, over a broad range of conditions and using the sandbar shark (Carcharhinus plumbeus) as a model organism. Our results indicate that the i-STAT system can generate useful measurements of whole blood pH, and the use of appropriate correction factors may increase the accuracy of results. The i-STAT system was, however, unable to generate reliable results for measurements of partial pressure of oxygen (PO2) and the derived parameter of haemoglobin O2 saturation. This is probably due to the effect of a closed-system temperature change on PO2 within the i-STAT cartridge and the fact that the temperature correction algorithms used by i-STAT assume a human temperature dependency of haemoglobin-O2 binding; in many ectotherms, this assumption will lead to equivocal i-STAT PO2 results. The in vivo partial pressure of CO2 (PCO2) in resting sandbar sharks is probably below the detection limit for PCO2 in the i-STAT system, and the measurement of higher PCO2 tensions was associated with a large measurement error. In agreement with previous work, our results indicate that the i-STAT system can generate useful data on whole blood pH in fishes, but not blood gases. PMID:27293687

  18. [Qualification of the Stewart variables for the assessment of the acid-base status in healthy dogs and dogs with different diseases].

    PubMed

    Siegling-Vlitakis, Christiane; Kohn, Barbara; Kellermeier, Claudia; Schmitz, Rose; Hartmann, Helmut

    2007-01-01

    Peter Stewart criticized the traditional theory of the acid-base status by Henderson-Hasselbalch as too simple and incomplete. He developed a new model with 3 independent variables: (1) pCO2, (2) SID (strong ion difference) and (3) Atot (Acid total). In healthy and ill dogs the diagnostic usefulness of both acid-base models were compared. This study included n=58 healthy dogs and 3 clinical cases of sick dogs. The age of the healthy dogs was 5.0 (2.0-7.0) years (= median (1.-3. quartil)). The 3 clinical cases included (1) a dog with septic shock, (2) with acute renal insufficiency, and (3) with hypovolaemic shock due to gastric torsion. Venous blood was taken of all dogs and the acid-base parameters were determined within < or =30 minutes. Electrolytes and albumin were determined in blood serum and used for calculation of the Stewart variables. Limits of reference intervals (x+/-1.96 - s) were determined for the healthy dogs yielding pCO2 = 3.6-6.5 kPa, [SID3] = 33.1-50.9 mmol/l resp. [SID4] = 31.8-49.6 mmol/l and [Al = 8.5-13.1 mmol/l. In Case 1 the Henderson-Hasselbalch parameters demonstrated the presence of a strong metabolic acidosis with mild respiratory influence (pH, [HCO3-], [BE] and PCO2 at upper range of normal). Analysis of the Stewart variables [SID3] resp. [SID4] revealed an electrolyte imbalance with [Cl-] and [lactate-] as the reason for metabolic acidosis. Case 2 showed a metabolic acidosis with respiratory compensation (pH, [HCO3-], [BE] and PCO2). Analysis of the Stewart variables with [SID3] resp. [SID4 caused by [K+], [Na+] and [lactate-]demonstrated the acidotic metabolism due to a renal malfunction. Case 3 had a metabolic acidosis (pH-value in the lower range) caused by electrolyte imbalances ([SID4]. The Stewart variables allow a better understanding of the causes of acid-base-disturbances in animals with implications for successful therapy via infusion.

  19. Effects of ammonium chloride and sulfate on acid-base status and calcium metabolism of dry Jersey cows.

    PubMed

    Wang, C; Beede, D K

    1992-03-01

    Eight nonlactating, nonpregnant Jersey cows were used in a crossover experiment with two 28-d periods. The control diet consisted of corn silage plus a concentrate mix (68:32, DM basis). The treatment diet was the same, except that NH4Cl and (NH4)2SO4 (98 g of each/d per cow) were added to the concentrate. Cows fed the treatment diet had lower blood pH, higher ionized Ca in blood, and more urinary excretion of Ca, titratable acid, and ammonium than cows fed the control diet. For cows fed the treatment diet, ionized Ca in blood was greater after equal amounts of Na2-EDTA were infused to both treatment groups, and treatment cows recovered faster after infusion of Na2-EDTA was stopped than did control cows. The treatment diet induced mild metabolic acidosis and increased the cows' ability to maintain normal blood Ca concentrations; it potentially could reduce incidence of milk fever.

  20. Acid-Base Homeostasis.

    PubMed

    Hamm, L Lee; Nakhoul, Nazih; Hering-Smith, Kathleen S

    2015-12-01

    Acid-base homeostasis and pH regulation are critical for both normal physiology and cell metabolism and function. The importance of this regulation is evidenced by a variety of physiologic derangements that occur when plasma pH is either high or low. The kidneys have the predominant role in regulating the systemic bicarbonate concentration and hence, the metabolic component of acid-base balance. This function of the kidneys has two components: reabsorption of virtually all of the filtered HCO3(-) and production of new bicarbonate to replace that consumed by normal or pathologic acids. This production or generation of new HCO3(-) is done by net acid excretion. Under normal conditions, approximately one-third to one-half of net acid excretion by the kidneys is in the form of titratable acid. The other one-half to two-thirds is the excretion of ammonium. The capacity to excrete ammonium under conditions of acid loads is quantitatively much greater than the capacity to increase titratable acid. Multiple, often redundant pathways and processes exist to regulate these renal functions. Derangements in acid-base homeostasis, however, are common in clinical medicine and can often be related to the systems involved in acid-base transport in the kidneys.

  1. Effects of acid rain on forest nutrient status

    SciTech Connect

    Johnson, D.W.; Turner, J.; Kelly, J.M.

    1982-06-01

    The paper presents an extensive literature review that deals with the assessment of the effects of acidic atmospheric inputs on forest nutrient status within the context of natural, internal acid production by carbonic and organic acids as well as the nutrient inputs and drains by management practices such as harvesting, fire and fertilization. 123 refs.

  2. High dietary selenium and vitamin E supplementation ameliorates the impacts of heat load on oxidative status and acid-base balance in sheep.

    PubMed

    Chauhan, S S; Celi, P; Leury, B J; Dunshea, F R

    2015-07-01

    The objective of this study was to determine the efficacy of supranutritional dietary selenium and vitamin E (Vit E) to ameliorate the effect of heat stress (HS) on oxidative status and acid-base balance in sheep. Thirty-two Merino × Poll Dorset ewes were acclimated to indoor individual pen feeding of a pelleted control diet (0.24 g Se and 10 IU of Vit E/kg DM) for 1 wk. Sheep were then moved to metabolism cages in climatic chambers and randomly allocated to a 2 × 2 × 2 factorial design with the respective factors being dietary Se (0.24 and 1.20 mg/kg DM as Sel-Plex; Alltech, Australia), Vit E (10 and 100 IU/kg DM), and temperature for 2 wk. After 1 wk of acclimation in metabolic cages, 1 climatic chamber continued on thermoneutral (TN) conditions (18°C to 21°C and 40% to 50% relative humidity [RH]), and the other one was set to HS conditions (28°C to 40°C and 30% to 40% RH) for 1 wk. The sheep were then returned to individual pens and fed the control diet for 1 wk before being returned to the same diet as in the first period but a reversed thermal treatment for a further 2 wk. Physiological parameters were recorded 3 times daily, and blood samples were collected on d 1 and 7 of thermal treatment. Average respiration rate and rectal temperature of sheep were increased (P < 0.001) during HS; however, combined supranutritional supplementation of Se and Vit E reversed the effects of HS. Sheep given the high Se and high Vit E diet had a lower respiration rate (191 vs. 232 breaths/min; P = 0.012) and rectal temperature (40.33°C vs. 40.58°C; P = 0.039) under peak HS (1700 h) compared with those fed the low Se and low Vit E diet. Plasma reactive oxygen metabolites concentrations were reduced (P = 0.048) by 20%, whereas biological antioxidant potential was increased (P = 0.17) by 10% in sheep fed the high Se and high Vit E diet compared with those fed the low Se and low Vit E diet. Blood pH was elevated (P = 0.007) and bicarbonate was reduced (P = 0.049) under HS

  3. Using Willie's Acid-Base Box for Blood Gas Analysis

    ERIC Educational Resources Information Center

    Dietz, John R.

    2011-01-01

    In this article, the author describes a method developed by Dr. William T. Lipscomb for teaching blood gas analysis of acid-base status and provides three examples using Willie's acid-base box. Willie's acid-base box is constructed using three of the parameters of standard arterial blood gas analysis: (1) pH; (2) bicarbonate; and (3) CO[subscript…

  4. The Effects of Acid Rain on Forest Nutrient Status

    NASA Astrophysics Data System (ADS)

    Johnson, Dale W.; Turner, John; Kelly, J. M.

    1982-06-01

    The effects of acidic atmospheric inputs on forest nutrient status must be assessed within the context of natural, internal acid production by carbonic and organic acids as well as the nutrient inputs and drains by management practices such as harvesting, fire, and fertilization. In all cases the anion associated with acid inputs must be mobile in the soil if leaching is to occur; immobilization of anions can effectively prevent cation leaching. Soil acidification will occur only if the often substantial buffering capacity of the soil in question is exceeded by acid inputs and if cation weathering from primary minerals is insufficient to offset cation losses by leaching. Such circumstances are rare but certainly could occur in theory, at least, given sufficiently large acid inputs on poorly buffered soils. Soils most sensitive to change are thought to be those of moderately acid pH and low cation exchange capacity. Neither very acid soils nor neutral, highly buffered soils are sensitive to acidification by acid rain. Given extremely high acid inputs, acid rain can cause temporary increases in nitrogen mineralization and nitritication as well as Al mobilization in soils. While temporary increases in N availability can cause increased forest growth in N-deficient forests, increased Al availability can cause toxic reactions in tree roots. Little is known about tree Al toxicity levels as yet, however. It must be emphasized that assessment of acid rain effects is a problem of quantification. Given sufficiently high inputs on sensitive sites, negative effects of acid rain must occur, as is true of inputs of any substance, including H2O. Acid rain inputs of sufficient magnitude to cause acute effects, such as growth increase due to N mobilization or growth decrease due to Al mobilization, are apparently very rare under ambient field conditions. Long-term effects on forest nutrient status can be either beneficial or adverse, depending on site nutrient status, silvicultural

  5. The effects of acid rain on forest nutrient status

    SciTech Connect

    Johnson, D.W.; Turner, J.; Kelly, J.M.

    1982-06-01

    The effects of acidic atmospheric inputs on forest nutrient status must be assessed within the context of natural, internal acid production by carbonic and organic acids as well as the nutrient inputs and drains by management practices such as harvesting, fire, and fertilization. Soil acidification will occur only if the often substantial buffering capacity of the soil in question is exceeded by acid inputs and if cation weathering from primary minerals is insufficient to offset cation losses by leaching. Such circumstances are rare but certainly could occur given sufficiently large acid inputs on poorly buffered soils. Soils most sensitive to change are thought to be those of moderately acid pH and low cation exchange capacity. Neither very acid soils nor neutral, highly buffered soils are sensitive to acidification by acid rain. Given extremely high acid inputs, acid rain can cause temporary increases in nitrogen mineralization and nitrification as well as Al mobilization in soils. While temporary increases in N availability can cause increased forest growth in N-deficient forests, increased Al availability can cause toxic reactions in tree roots. Given sufficiently high inputs on sensitive sites, negative effects of acid rain must occur, as is true of inputs of any substance, including H/sub 2/O. Acid rain inputs of sufficient magnitude to cause acute effects, such as growth increase due to N mobilization or growth decrease due to Al mobilization, are apparently very rare under ambient field conditions. Long-term effects on forest nutrient status can be either beneficial or adverse, depending on site nutrient status, silvicultural practices, and amount of atmospheric inputs. (JMT)

  6. Phosphoric Acid Fuel Cell Technology Status

    NASA Technical Reports Server (NTRS)

    Simons, S. N.; King, R. B.; Prokopius, P. R.

    1981-01-01

    A review of the current phosphoric acid fuel cell system technology development efforts is presented both for multimegawatt systems for electric utility applications and for multikilowatt systems for on-site integrated energy system applications. Improving fuel cell performance, reducing cost, and increasing durability are the technology drivers at this time. Electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, and fuel selection are discussed.

  7. A Modern Approach to Acid-Base Chemistry

    ERIC Educational Resources Information Center

    Drago, Russell S.

    1974-01-01

    Summarizes current status of our knowledge about acid-base interactions, including Lewis considerations, experimental design, data about donor-acceptor systems, common misconceptions, and hard-soft acid-base model. Indicates that there is the possibility of developing unifying concepts for chemical reactions of inorganic compounds. (CC)

  8. Genetic strain and reproductive status affect endometrial fatty acid concentrations.

    PubMed

    Meier, S; Peterson, A J; Mitchell, M D; Littlejohn, M; Walker, C G; Roche, J R

    2009-08-01

    Poor reproductive performance limits cow longevity in seasonal, pasture-based dairy systems. Few differences in ovarian dynamics have been reported in different strains of Holstein-Friesian cows, implying that the uterine environment may be a key component determining reproductive success. To test the hypothesis that the uterine environment differs among genetic strains of the Holstein-Friesian cow, endometrial fatty acids (FA) were analyzed from New Zealand (NZ), and North American (NA) Holstein-Friesian cows. The effect of reproductive status was also investigated, with cows from both Holstein-Friesian strains slaughtered on either d 17 of the estrous cycle (termed cyclic) or d 17 of pregnancy (after embryo transfer; termed pregnant). Endometrial tissues were collected from 22 cows (NZ pregnant, n = 6; NZ cyclic, n = 4; NA pregnant, n = 6; NA cyclic, n = 6), and FA composition was analyzed. Daily plasma progesterone concentrations, milk production, milk FA composition, body weight, and body condition score were determined. Milk yield (4% fat-corrected milk) was similar for the NZ (28.5 kg/d) and NA (29.3 kg/d; SE 2.07 kg/d) cows, but NZ cows had a greater mean milk fat percentage. Mean plasma progesterone concentrations were significantly greater in NZ cows. Plasma progesterone concentrations were similar in the pregnant and cyclic groups. Mean length of the trophoblast recovered from the pregnant cows (NZ: 20.8 +/- 2.84 cm; NA: 27.9 +/- 10.23 cm) was not affected by genetic strain. Endometrial tissues from NZ cows contained greater concentrations of C17:0, C20:3n-3, and total polyunsaturated FA. The endometria from pregnant cows contained greater concentrations of C17:0, C20:2, and C20:3n-6, and less C20:1, C20:2, C20:5n-3. The observed changes in endometrial FA between Holstein-Friesian cows of different genetic origins or reproductive states may reflect differences in endometrial function and may affect reproductive function.

  9. Polyunsaturated fatty acid status of Dutch vegans and omnivores.

    PubMed

    Fokkema, M R; Brouwer, D A; Hasperhoven, M B; Hettema, Y; Bemelmans, W J; Muskiet, F A

    2000-11-01

    We compared the polyunsaturated fatty acid (PUFA) status of Dutch vegans and omnivores to investigate whether disparities can be explained by different diets and long chain PUFA (LCP) synthesis rates. Dietary intakes and fatty acid compositions of erythrocytes (RBC), platelets (PLT), plasma cholesterol esters (CE) and plasma triglycerides (TG) of 12 strict vegans and 15 age- and sex-matched omnivores were determined. Vegans had higher omega 6 (CE, TG), 18:2 omega 6 (RBC, CE, TG), 18:3 omega 6 (TG), 20:3 omega 6 (TG), 22:4 omega 6 (TG), 22:5 omega 3 (RBC, PLT), 22:5 omega 3/22:6 omega 3 (RBC, PLT) and 22:5 omega 6/22:6 omega 3 (RBC, PLT), and lower 22:4 omega 6 (RBC, PLT), 22:4 omega 6/22:5 omega 6 (RBC, PLT), omega 3 (CE), LCP omega 3 (CE, TG), 20:5 omega 3 (RBC, PLT, CE), 22:5 omega 3 (TG) and 22:6 omega 3 (all compartments). Vegans had lower 20:4 omega 6 (TG) after normalization of PUFA to 100%, and normalization of eicosanoid precursors to 100% revealed similar 20:4 omega 6 (all), higher 20:3 omega 6 (TG) and lower 20:5 omega 3 (all). High omega 6 (notably 18:2 omega 6) and low omega 3 (notably 20:5 omega 3, 22:6 omega 3) status in Dutch vegans derives from low dietary LCP omega 3 and 18:3 omega 3/18:2 omega 6 ratio. Higher 18:3 omega 6 and 20:3 omega 6 in their TG may reflect higher hepatic 20:4 omega 6 production rate, whereas higher 20:4 omega 6 and 22:4 omega 6 in omnivores indicates 20:4 omega 6 intake from meat.

  10. Molten fatty acid based microemulsions.

    PubMed

    Noirjean, Cecile; Testard, Fabienne; Dejugnat, Christophe; Jestin, Jacques; Carriere, David

    2016-06-21

    We show that ternary mixtures of water (polar phase), myristic acid (MA, apolar phase) and cetyltrimethylammonium bromide (CTAB, cationic surfactant) studied above the melting point of myristic acid allow the preparation of microemulsions without adding a salt or a co-surfactant. The combination of SANS, SAXS/WAXS, DSC, and phase diagram determination allows a complete characterization of the structures and interactions between components in the molten fatty acid based microemulsions. For the different structures characterized (microemulsion, lamellar or hexagonal phases), a similar thermal behaviour is observed for all ternary MA/CTAB/water monophasic samples and for binary MA/CTAB mixtures without water: crystalline myristic acid melts at 52 °C, and a thermal transition at 70 °C is assigned to the breaking of hydrogen bounds inside the mixed myristic acid/CTAB complex (being the surfactant film in the ternary system). Water determines the film curvature, hence the structures observed at high temperature, but does not influence the thermal behaviour of the ternary system. Myristic acid is partitioned in two "species" that behave independently: pure myristic acid and myristic acid associated with CTAB to form an equimolar complex that plays the role of the surfactant film. We therefore show that myristic acid plays the role of a solvent (oil) and a co-surfactant allowing the fine tuning of the structure of oil and water mixtures. This solvosurfactant behaviour of long chain fatty acid opens the way for new formulations with a complex structure without the addition of any extra compound. PMID:27241163

  11. Dietary, serum and urine ascorbic acid status in male athletes.

    PubMed

    Rokitzki, L; Hinkel, S; Klemp, C; Cufi, D; Keul, J

    1994-10-01

    The ascorbic acid (AA)-status of 14 marathon runners, 12 soccer players, 9 wrestlers, 9 basketball players and 16 controls was determined. A 7-day food weighed record was kept to quantify the AA-intake. In addition, the AA-serum concentrations and urinary ascorbate excretion were measured. The AA-intake of all 44 athletes (median, 26th-75th percentile) was 180.7 (188-239) mg/d, the serum concentration 70.6 (65.7-80.2 mumol/l) and the urine ascorbate excretion 1531 (391-2934) mumol/g creatine. No significant differences could be observed between the various sport groups, or between the sport groups and controls with respect to absolute (mg/d) and relative (mg/g body weight) AA-intake, serum and urine concentrations. Only a few of the athletes had AA-intake below the RDA or serum- or urine levels smaller than the decision limit. The absolute AA-intake (n = 44) from the 7-day record (r = 0.49, p < 0.0009) and the AA-intake on the last day (1-day) prior to urine collection (r = 0.90, p < 0.0000) correlate moderately/strongly with the urinary excretion. Between AA-intake (7-day) and serum concentration there is a correlation of r = 0.59, p < 0.0000. The AA-status of highly trained athletes does not differ significantly from the control group in spite of intensive daily training. Thus, AA-supplementation beyond the normal daily intake does not appear necessary.

  12. Caffeic acid phenethyl ester prevents apoptotic cell death in the developing rat brain after pentylenetetrazole-induced status epilepticus.

    PubMed

    Yiş, Uluç; Topçu, Yasemin; Özbal, Seda; Tuğyan, Kazım; Bayram, Erhan; Karakaya, Pakize; Yilmaz, Osman; Kurul, Semra Hız

    2013-11-01

    Population-based studies suggest that seizure incidence is highest during the first year of life, and early-life seizures frequently result in the development of epilepsy and behavioral alterations later in life. The early-life insults like status epilepticus often lead to epileptogenesis, a process in which initial brain injury triggers cascades of molecular, cellular, and network changes and eventually spontaneous seizures. Caffeic acid phenethyl ester is an active component of propolis obtained from honeybees and has neuroprotective properties. The aim of this study was to investigate whether caffeic acid phenethyl ester exerts neuroprotective effects on the developing rat brain after status epilepticus. Twenty-one dams reared Wistar male rats, and 21-day-old rats were divided into three groups: control group, pentylenetetrazole-induced status epilepticus group, and caffeic acid phenethyl ester-treated group. Status epilepticus was induced on the first day of experiment. Caffeic acid phenethyl ester injections (30 mg/kg intraperitoneally) started 40 min after the tonic phase of status epilepticus was reached, and the injections of caffeic acid phenethyl ester were repeated over 5 days. Rats were sacrificed, and brain tissues were collected on the 5th day of experiment after the last injection of caffeic acid phenethyl ester. Apoptotic cell death was evaluated. Histopathological examination showed that caffeic acid phenethyl ester significantly preserved the number of neurons in the CA1, CA3, and dentate gyrus regions of the hippocampus and the prefrontal cortex. It also diminished apoptosis in the hippocampus and the prefrontal cortex. In conclusion, this experimental study suggests that caffeic acid phenethyl ester administration may be neuroprotective in status epilepticus in the developing rat brain.

  13. Nucleic acid based logical systems.

    PubMed

    Han, Da; Kang, Huaizhi; Zhang, Tao; Wu, Cuichen; Zhou, Cuisong; You, Mingxu; Chen, Zhuo; Zhang, Xiaobing; Tan, Weihong

    2014-05-12

    Researchers increasingly visualize a significant role for artificial biochemical logical systems in biological engineering, much like digital logic circuits in electrical engineering. Those logical systems could be utilized as a type of servomechanism to control nanodevices in vitro, monitor chemical reactions in situ, or regulate gene expression in vivo. Nucleic acids (NA), as carriers of genetic information with well-regulated and predictable structures, are promising materials for the design and engineering of biochemical circuits. A number of logical devices based on nucleic acids (NA) have been designed to handle various processes for technological or biotechnological purposes. This article focuses on the most recent and important developments in NA-based logical devices and their evolution from in vitro, through cellular, even towards in vivo biological applications.

  14. Radiometric acid-base titrations.

    PubMed

    Erdey, L; Gimesi, O; Szabadváry, F

    1969-03-01

    Acid-base titrations can be performed with radiometric end-point detection by use of labelled metal salts (e.g., ZnCl(2), HgCl(2)). Owing to the formation or dissolution of the corresponding hydroxide after the equivalence point, the activity of the titrated solution linearly increases or decreases as excess of standard solution is added. The end-point of the titration is determined graphically.

  15. Fatty acid status and its relationship to cognitive decline and homocysteine levels in the elderly.

    PubMed

    Baierle, Marília; Vencato, Patrícia H; Oldenburg, Luiza; Bordignon, Suelen; Zibetti, Murilo; Trentini, Clarissa M; Duarte, Marta M M F; Veit, Juliana C; Somacal, Sabrina; Emanuelli, Tatiana; Grune, Tilman; Breusing, Nicolle; Garcia, Solange C

    2014-09-01

    Polyunsaturated fatty acids (PUFAs), especially the n-3 series, are known for their protective effects. Considering that cardiovascular diseases are risk factors for dementia, which is common at aging, the aim of this study was to evaluate whether fatty acid status in the elderly was associated with cognitive function and cardiovascular risk. Forty-five elderly persons (age ≥ 60 years) were included and divided into two groups based on their Mini-Mental Status Examination score adjusted for educational level: the case group (n = 12) and the control group (n = 33). Serum fatty acid composition, homocysteine (Hcy), hs-CRP, lipid profile and different cognitive domains were evaluated. The case group, characterized by reduced cognitive performance, showed higher levels of 14:0, 16:0, 16:1n-7 fatty acids and lower levels of 22:0, 24:1n-9, 22:6n-3 (DHA) and total PUFAs compared to the control group (p < 0.05). The n-6/n-3 ratio was elevated in both study groups, whereas alterations in Hcy, hs-CRP and lipid profile were observed in the case group. Cognitive function was positively associated with the 24:1n-9, DHA and total n-3 PUFAs, while 14:0, 16:0 and 16:1n-7 fatty acids, the n-6/n-3 ratio and Hcy were inversely associated. In addition, n-3 PUFAs, particularly DHA, were inversely associated with cardiovascular risk, assessed by Hcy levels in the elderly. PMID:25221976

  16. Use of an Acid-Base Table.

    ERIC Educational Resources Information Center

    Willis, Grover; And Others

    1986-01-01

    Identifies several ways in which an acid-base table can provide students with information about chemical reactions. Cites examples of the chart's use and includes a table which indicates the strengths of some common acids and bases. (ML)

  17. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    ERIC Educational Resources Information Center

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  18. The association between low-grade inflammation, iron status and nucleic acid oxidation in the elderly

    PubMed Central

    Broedbaek, Kasper; Siersma, Volkert; Andersen, Jon T.; Petersen, Morten; Afzal, Shoaib; Hjelvang, Brian; Weimann, Allan; Semba, Richard D.; Ferrucci, Luigi; Poulsen, Henrik E.

    2016-01-01

    This study applied a case-control approach to investigate the association between low-grade inflammation, defined by high values within the normal range of C-reactive protein (CRP) and interleukin-6 (IL-6), and urinary markers of nucleic acid oxidation. No differences in excretion of urinary markers of nucleic acid oxidation between cases and controls were found and multivariable linear regression analysis showed no association between urinary markers of nucleic acid oxidation and inflammatory markers. Post-hoc multivariable linear regression analysis showed significant associations between nucleic acid oxidation and various iron status markers and especially a close relationship between nucleic acid oxidation and ferritin. This study shows no association between low-grade inflammation and urinary markers of nucleic acid oxidation in a population of elderly Italian people. The results suggest that low-grade inflammation only has a negligible impact on whole body nucleic acid oxidation, whereas iron status seems to be of great importance. PMID:21275071

  19. Biotechnological production of muconic acid: current status and future prospects.

    PubMed

    Xie, Neng-Zhong; Liang, Hong; Huang, Ri-Bo; Xu, Ping

    2014-01-01

    Muconic acid (MA), a high value-added bio-product with reactive dicarboxylic groups and conjugated double bonds, has garnered increasing interest owing to its potential applications in the manufacture of new functional resins, bio-plastics, food additives, agrochemicals, and pharmaceuticals. At the very least, MA can be used to produce commercially important bulk chemicals such as adipic acid, terephthalic acid and trimellitic acid. Recently, great progress has been made in the development of biotechnological routes for MA production. This present review provides a comprehensive and systematic overview of recent advances and challenges in biotechnological production of MA. Various biological methods are summarized and compared, and their constraints and possible solutions are also described. Finally, the future prospects are discussed with respect to the current state, challenges, and trends in this field, and the guidelines to develop high-performance microbial cell factories are also proposed for the MA production by systems metabolic engineering. PMID:24751381

  20. Reconceptualizing retirement: A status-based approach.

    PubMed

    Hershenson, David B

    2016-08-01

    The one thing on which essentially all retirement scholars agree is that there is no generally accepted definition of the term "retirement." Hence, it is not surprising that a plethora of competing models of the stages of retirement has been generated. To cut this Gordian knot, this paper proposes that the concept of statuses, which are not necessarily mutually exclusive or sequential, replace the idea of stages. Statuses better reflect observed human behavior and are more open to multicultural application, thus facilitating retirement research and clinical practice. The retirement statuses proposed here, which can exist in any combination or sequence, are retrenchment, exploration, try-out, involvement, reconsideration, and exiting (forming the acronym RETIRE).

  1. Perinatal protein restriction affects milk free amino acid and fatty acid profile in lactating rats: potential role on pup growth and metabolic status.

    PubMed

    Martin Agnoux, Aurore; Antignac, Jean-Philippe; Boquien, Clair-Yves; David, Agnes; Desnots, Emmanuelle; Ferchaud-Roucher, Veronique; Darmaun, Dominique; Parnet, Patricia; Alexandre-Gouabau, Marie-Cécile

    2015-07-01

    Perinatal undernutrition affects not only fetal and neonatal growth but also adult health outcome, as suggested by the metabolic imprinting concept. Although maternal milk is the only channel through which nutrients are transferred from mother to offspring during the postnatal period, the impact of maternal undernutrition on milk composition is poorly understood. The present study investigates, in a rat model of nutritional programming, the effects of feeding an isocaloric, low-protein diet throughout gestation and lactation on milk composition and its possible consequences on offspring's growth and metabolic status. We used an integrated methodological approach that combined targeted analyses of macronutrients, free amino acid and fatty acid content throughout lactation, with an untargeted mass-spectrometric-based metabolomic phenotyping. Whereas perinatal dietary protein restriction failed to alter milk protein content, it dramatically decreased the concentration of most free amino acids at the end of lactation. Interestingly, a decrease of several amino acids involved in insulin secretion or gluconeogenesis was observed, suggesting that maternal protein restriction during the perinatal period may impact the insulinotrophic effect of milk, which may, in turn, account for the slower growth of the suckled male offspring. Besides, the decrease in sulfur amino acids may alter redox status in the offspring. Maternal undernutrition was also associated with an increase in milk total fatty acid content, with modifications in their pattern. Altogether, our results show that milk composition is clearly influenced by maternal diet and suggest that alterations in milk composition may play a role in offspring growth and metabolic programming. PMID:25935308

  2. Carbonic anhydrase and acid-base regulation in fish.

    PubMed

    Gilmour, K M; Perry, S F

    2009-06-01

    Carbonic anhydrase (CA) is the zinc metalloenzyme that catalyses the reversible reactions of CO(2) with water. CA plays a crucial role in systemic acid-base regulation in fish by providing acid-base equivalents for exchange with the environment. Unlike air-breathing vertebrates, which frequently utilize alterations of breathing (respiratory compensation) to regulate acid-base status, acid-base balance in fish relies almost entirely upon the direct exchange of acid-base equivalents with the environment (metabolic compensation). The gill is the critical site of metabolic compensation, with the kidney playing a supporting role. At the gill, cytosolic CA catalyses the hydration of CO(2) to H(+) and HCO(3)(-) for export to the water. In the kidney, cytosolic and membrane-bound CA isoforms have been implicated in HCO(3)(-) reabsorption and urine acidification. In this review, the CA isoforms that have been identified to date in fish will be discussed together with their tissue localizations and roles in systemic acid-base regulation.

  3. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1995-09-12

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

  4. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1995-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  5. Status of commercial phosphoric acid fuel cell system development

    NASA Technical Reports Server (NTRS)

    Warshay, M.; Prokopius, P. R.; Simons, S. N.; King, R. B.

    1981-01-01

    A review of the current commercial phosphoric acid fuel cell system development efforts is presented. In both the electric utility and on-site integrated energy system applications, reducing cost and increasing reliability are important. The barrier to the attainment of these goals has been materials. The differences in approach among the three major participants are their technological features, including electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, fuel selection and system design philosophy.

  6. Students' Alternate Conceptions on Acids and Bases

    ERIC Educational Resources Information Center

    Pan, Hanqing; Henriques, Laura

    2015-01-01

    Knowing what students bring to the classroom can and should influence how we teach them. This study is a review of the literature associated with secondary and postsecondary students' ideas about acids and bases. It was found that there are six types of alternate ideas about acids and bases that students hold. These are: macroscopic properties of…

  7. The Kidney and Acid-Base Regulation

    ERIC Educational Resources Information Center

    Koeppen, Bruce M.

    2009-01-01

    Since the topic of the role of the kidneys in the regulation of acid base balance was last reviewed from a teaching perspective (Koeppen BM. Renal regulation of acid-base balance. Adv Physiol Educ 20: 132-141, 1998), our understanding of the specific membrane transporters involved in H+, HCO , and NH transport, and especially how these…

  8. The Conjugate Acid-Base Chart.

    ERIC Educational Resources Information Center

    Treptow, Richard S.

    1986-01-01

    Discusses the difficulties that beginning chemistry students have in understanding acid-base chemistry. Describes the use of conjugate acid-base charts in helping students visualize the conjugate relationship. Addresses chart construction, metal ions, buffers and pH titrations, and the organic functional groups and nonaqueous solvents. (TW)

  9. Base excess or buffer base (strong ion difference) as measure of a non-respiratory acid-base disturbance.

    PubMed

    Siggaard-Andersen, O; Fogh-Andersen, N

    1995-01-01

    Stewart in 1983 (Can J Physiol Pharmacol 1983: 61: 1444) reintroduced plasma buffer base under the name "strong ion difference" (SID). Buffer base was originally introduced by Singer and Hastings in 1948 (Medicine (Baltimore) 1948: 27: 223). Plasma buffer base, which is practically equal to the sum of bicarbonate and albuminate anions, may be increased due to an excess of base or due to an increased albumin concentration. Singer and Hastings did not consider changes in albumin as acid-base disorders and therefore used the base excess, i.e., the actual buffer base minus the buffer base at normal pH and pCO2, as measure of a non-respiratory acid-base disturbance. Stewart and followers, however, consider changes in albumin concentration to be acid-base disturbances: a patient with normal pH, pCO2, and base excess but with increased plasma buffer base due to increased plasma albumin concentration get the diagnoses metabolic (strong ion) alkalosis (because plasma buffer base is increased) combined with metabolic hyperalbuminaemic acidosis. Extrapolating to whole blood, anaemia and polycytaemia should represent types of metabolic alkalosis and acidosis, respectively. This reveals that the Stewart approach is absurd and anachronistic in the sense that an increase or decrease in any anion is interpreted as indicating an excess or deficit of a specific acid. In other words, a return to the archaic definitions of acids and bases as being the same as anions and cations. We conclude that the acid-base status (the hydrogen ion status) of blood and extracellular fluid is described in terms of the arterial pH, the arterial pCO2, and the extracellular base excess. It is measured with a modern pH-blood gas analyser. The electrolyte status of the plasma is a description of the most important electrolytes, usually measured in venous blood with a dedicated electrolyte analyser, i.e., Na+, Cl-, HCO3-, and K+. Albumin anions contribute significantly to the anions, but calculation

  10. Effects of thyroid hormone status on metabolic pathways of arachidonic acid in mice and humans: A targeted metabolomic approach.

    PubMed

    Yao, Xuan; Sa, Rina; Ye, Cheng; Zhang, Duo; Zhang, Shengjie; Xia, Hongfeng; Wang, Yu-cheng; Jiang, Jingjing; Yin, Huiyong; Ying, Hao

    2015-01-01

    Symptoms of cardiovascular diseases are frequently found in patients with hypothyroidism and hyperthyroidism. However, it is unknown whether arachidonic acid metabolites, the potent mediators in cardiovascular system, are involved in cardiovascular disorders caused by hyperthyroidism and hypothyroidism. To answer this question, serum levels of arachidonic acid metabolites in human subjects with hypothyroidism, hyperthyroidism and mice with hypothyroidism or thyroid hormone treatment were determined by a mass spectrometry-based method. Over ten arachidonic acid metabolites belonging to three catalytic pathways: cyclooxygenases, lipoxygenases, and cytochrome P450, were quantified simultaneously and displayed characteristic profiles under different thyroid hormone status. The level of 20-hydroxyeicosatetraenoic acid, a cytochrome P450 metabolite, was positively correlated with thyroid hormone level and possibly contributed to the elevated blood pressured in hyperthyroidism. The increased prostanoid (PG) I2 and decreased PGE2 levels in hypothyroid patients might serve to alleviate atherosclerosis associated with dyslipidemia. The elevated level of thromboxane (TX) A2, as indicated by TXB2, in hyperthyroid patients and mice treated with thyroid hormone might bring about pulmonary hypertension frequently found in hyperthyroid patients. In conclusion, our prospective study revealed that arachidonic acid metabolites were differentially affected by thyroid hormone status. Certain metabolites may be involved in cardiovascular disorders associated with thyroid diseases. PMID:25841349

  11. Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

    PubMed

    Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

    2002-12-01

    Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

  12. Electrochemical nanomaterial-based nucleic acid aptasensors.

    PubMed

    Palchetti, Ilaria; Mascini, Marco

    2012-04-01

    Recent progress in the development of electrochemical nanomaterial-aptamer-based biosensors is summarized. Aptamers are nucleic acid ligands that can be generated against amino acids, drugs, proteins, and other molecules. They are isolated from a large random library of synthetic nucleic acids by an iterative process of binding, separation, and amplification, called systematic evolution of ligands by exponential enrichment (SELEX). In this review, different methods of integrating aptamers with different nanomaterials and nanoparticles for electrochemical biosensing application are described.

  13. Influence of folic acid-fortified foods on folate status in a folate depletion-repletion rat model.

    PubMed

    O'Leary, K; Sheehy, P J

    2001-04-01

    An increasing number of foods fortified with varying levels of folic acid are appearing in the market place, targeted either at the general population or at specific consumer groups. Although it is assumed that the folate in these products should be highly bioavailable, there is a need to carry out studies to ascertain that this is, in fact, the case. The present study investigated the ability of selected folic acid-fortified foods (targeted at different types of consumer) to increase the folate status of folate-deficient rats. Forty-two weanling male rats (Wistar strain) were fed a folate-deficient diet containing 1 % succinyl sulfathiazole (w/w) for 28 d. Following depletion, seven rats were randomly assigned to each of five repletion diets containing folic acid, Complan, Slim Fast, Opti-Fuel2 or Cola Coa calculated to provide 200 microg folate/kg of each diet. Calculations were based on folate information from the product labels. After a further 28 d, plasma, liver and kidney folate concentrations were determined by microbiological assay. Plasma homocysteine was measured by HPLC as a functional indicator of folate status. The folate content of the foods was measured by tri-enzyme extraction followed by microbiological assay. Our analyses suggest that there may be considerable inaccuracies on the part of the manufacturers in relation to the folate declarations on the product labels. Despite this, the four foods evaluated were highly effective in elevating plasma, liver and kidney folate and lowering plasma homocysteine concentrations in rats. These results lend support to the policy of food fortification with folic acid as a means of raising the folate status of the population, and in particular to the fortification of specific foods which may target areas of the population where increased folate status is most needed.

  14. Excitatory amino acid transporter 2 downregulation correlates with thalamic neuronal death following kainic acid-induced status epilepticus in rat.

    PubMed

    Sakurai, Masashi; Kurokawa, Haruna; Shimada, Akinori; Nakamura, Kazuhiro; Miyata, Hajime; Morita, Takehito

    2015-02-01

    Recurrent seizures without interictal resumption (status epilepticus) have been reported to induce neuronal death in the midline thalamic region that has functional roles in memory and decision-making; however, the pathogenesis underlying status epilepticus-induced thalamic neuronal death is yet to be determined. We performed histological and immunohistochemical studies as well as cerebral blood flow measurement using 4.7 tesla magnetic resonance imaging spectrometer on midline thalamic region in Sprague-Dawley rats (n = 75, male, 7 weeks after birth, body weight 250-300 g) treated with intraperitoneal injection of kainic acid (10 mg/kg) to induce status epilepticus (n = 55) or normal saline solution (n = 20). Histological study using paraffin-embedded specimens revealed neuronal death showing ischemic-like changes and Fluoro-Jade C positivity with calcium deposition in the midline thalamic region of epileptic rats. The distribution of neuronal death was associated with focal loss of immunoreactivity for excitatory amino acid transporter 2 (EAAT2), stronger immunoreaction for glutamate and increase in number of Iba-1-positive microglial cells showing swollen cytoplasm and long processes. Double immunofluorescence study demonstrated co-expression of interleukin-1 beta (IL-1β) and inducible nitric oxide synthase (iNOS) within microglial cells, and loss of EAAT2 immunoreactivity in reactive astrocytes. These microglial alterations and astrocytic EAAT2 downregulation were also observed in tissue without obvious neuronal death in kainic acid-treated rats. These results suggest the possible role of glutamate excitotoxicity in neuronal death in the midline thalamic region following kainic acid-induced status epilepticus due to astrocytic EAAT2 downregulation following microglial activation showing upregulation of IL-1β and iNOS.

  15. Base-acid hybrid water electrolysis.

    PubMed

    Chen, Long; Dong, Xiaoli; Wang, Fei; Wang, Yonggang; Xia, Yongyao

    2016-02-21

    A base-acid hybrid electrolytic system with a low onset voltage of 0.78 V for water electrolysis was developed by using a ceramic Li-ion exchange membrane to separate the oxygen-evolving reaction (OER) in a basic electrolyte solution containing the Li-ion and hydrogen-evolving reaction (HER) in an acidic electrolyte solution. PMID:26804323

  16. Jammed acid-base reactions at interfaces.

    PubMed

    Gibbs-Davis, Julianne M; Kruk, Jennifer J; Konek, Christopher T; Scheidt, Karl A; Geiger, Franz M

    2008-11-19

    Using nonlinear optics, we show that acid-base chemistry at aqueous/solid interfaces tracks bulk pH changes at low salt concentrations. In the presence of 10 to 100 mM salt concentrations, however, the interfacial acid-base chemistry remains jammed for hours, until it finally occurs within minutes at a rate that follows the kinetic salt effect. For various alkali halide salts, the delay times increase with increasing anion polarizability and extent of cation hydration and lead to massive hysteresis in interfacial acid-base titrations. The resulting implications for pH cycling in these systems are that interfacial systems can spatially and temporally lag bulk acid-base chemistry when the Debye length approaches 1 nm.

  17. Liquid human milk fortifier significantly improves docosahexaenoic and arachidonic acid status in preterm infants.

    PubMed

    Berseth, C L; Harris, C L; Wampler, J L; Hoffman, D R; Diersen-Schade, D A

    2014-09-01

    We report the fatty acid composition of mother׳s own human milk from one of the largest US cohorts of lactating mothers of preterm infants. Milk fatty acid data were used as a proxy for intake at enrollment in infants (n=150) who received human milk with a powder human milk fortifier (HMF; Control) or liquid HMF [LHMF; provided additional 12mg docosahexaenoic acid (DHA), 20mg arachidonic acid (ARA)/100mL human milk]. Mothers provided milk samples (n=129) and reported maternal DHA consumption (n=128). Infant blood samples were drawn at study completion (Study Day 28). Human milk and infant PPL fatty acids were analyzed using capillary column gas chromatography. DHA and ARA were within ranges previously published for US term and preterm human milk. Compared to Control HMF (providing no DHA or ARA), human milk fortified with LHMF significantly increased infant PPL DHA and ARA and improved preterm infant DHA and ARA status.

  18. Graphene-based membranes: status and prospects.

    PubMed

    Yoon, Hee Wook; Cho, Young Hoon; Park, Ho Bum

    2016-02-13

    Recently, graphene-based membranes have been extensively studied, represented by two distinct research directions: (i) creating pores in graphene basal plane and (ii) engineering nanochannels in graphene layers. Most simulation results predict that porous graphene membranes can be much more selective and permeable than current existing membranes, also evidenced by some experimental results for gas separation and desalination. In addition, graphene oxide has been widely investigated in layered membranes with two-dimensional nanochannels, showing very intriguing separation properties. This review will cover state-of-the-art of graphene-based membranes, and also provide a material guideline on future research directions suitable for practical membrane applications.

  19. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    SciTech Connect

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  20. Integrated Data Base Program: a status report

    SciTech Connect

    Notz, K.J.; Klein, J.A.

    1984-06-01

    The Integrated Data Base (IDB) Program provides official Department of Energy (DOE) data on spent fuel and radioactive waste inventories, projections, and characteristics. The accomplishments of FY 1983 are summarized for three broad areas: (1) upgrading and issuing of the annual report on spent fuel and radioactive waste inventories, projections, and characteristics, including ORIGEN2 applications and a quality assurance plan; (2) creation of a summary data file in user-friendly format for use on a personal computer and enhancing user access to program data; and (3) optimizing and documentation of the data handling methodology used by the IDB Program and providing direct support to other DOE programs and sites in data handling. Plans for future work in these three areas are outlined. 23 references, 11 figures.

  1. Salidroside protects against kainic acid-induced status epilepticus via suppressing oxidative stress.

    PubMed

    Si, Pei-Pei; Zhen, Jun-Li; Cai, Yun-Lei; Wang, Wen-Jing; Wang, Wei-Ping

    2016-04-01

    There are numerous mechanisms by which the brain generates seizures. It is well known that oxidative stress plays a pivotal role in status epilepticus (SE). Salidroside (SDS) extracted from Rhodiola rosea L. shows multiple bioactive properties, such as neuroprotection and antioxidant activity in vitro and in vivo. This study explored the role of SDS in kainic acid (KA)-induced SE and investigated the underlying mechanism. Latency to SE increased in the SDS-pretreated mice compared to the KA group, while the percentage of incidence of SE was significantly reduced. These results suggested that pretreatment with SDS not only delayed SE, but it also decreased the incidence of SE induced by KA. KA increased MDA level and reduced the production of SOD and GSH at multiple timepoints after KA administration. SDS inhibited the change of MDA, SOD and GSH induced by KA prior to SE onset, indicating that SDS protects against KA-induced SE via suppressing oxidative stress. Based on these results, we investigated the possible molecular mechanism of SDS. Pretreatment with SDS reversed the KA-induced decrease in AMP-activated protein kinase (AMPK); increased the sirtuin 1 (SIRT1) deacetylase activity in KA-treated mice, which had no demonstrable effect on SIRT1 mRNA and protein; and suppressed the KA-induced increase in Ace-FoxO1. These results showed that AMPK/SIRT1/FoxO1 signaling is possibly the molecular mechanism of neuroprotection by SDS.

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

    PubMed

    Pophaly, Sarang Dilip; Singh, Rameshwar; Pophaly, Saurabh Dilip; Kaushik, Jai K; Tomar, Sudhir Kumar

    2012-08-25

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

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

    PubMed Central

    2012-01-01

    Lactic acid bacteria (LAB) have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms. PMID:22920585

  4. [Kidney, Fluid, and Acid-Base Balance].

    PubMed

    Shioji, Naohiro; Hayashi, Masao; Morimatsu, Hiroshi

    2016-05-01

    Kidneys play an important role to maintain human homeostasis. They contribute to maintain body fluid, electrolytes, and acid-base balance. Especially in fluid control, we, physicians can intervene body fluid balance using fluid resuscitation and diuretics. In recent years, one type of fluid resuscitation, hydroxyl ethyl starch has been extensively studied in the field of intensive care. Although their effects on fluid resuscitation are reasonable, serious complications such as kidney injury requiring renal replacement therapy occur frequently. Now we have to pay more attention to this important complication. Another topic of fluid management is tolvaptan, a selective vasopressin-2 receptor antagonist Recent randomized trial suggested that tolvaptan has a similar supportive effect for fluid control and more cost effective compared to carperitide. In recent years, Stewart approach is recognized as one important tool to assess acid-base balance in critically ill patients. This approach has great value, especially to understand metabolic components in acid-base balance. Even for assessing the effects of kidneys on acid-base balance, this approach gives us interesting insight. We should appropriately use this new approach to treat acid-base abnormality in critically ill patients. PMID:27319095

  5. Regression-Based Estimates of Observed Functional Status in Centenarians

    ERIC Educational Resources Information Center

    Mitchell, Meghan B.; Miller, L. Stephen; Woodard, John L.; Davey, Adam; Martin, Peter; Burgess, Molly; Poon, Leonard W.

    2011-01-01

    Purpose of the Study: There is lack of consensus on the best method of functional assessment, and there is a paucity of studies on daily functioning in centenarians. We sought to compare associations between performance-based, self-report, and proxy report of functional status in centenarians. We expected the strongest relationships between proxy…

  6. India-based Neutrino Observatory(INO): A Status Report

    SciTech Connect

    Murthy, M. V. N.

    2011-11-23

    We present a status report on the proposed India-based Neutrino Observatory (INO). Various aspects of the INO project such as its location, the present status of the detector development, physics goals and simulation studies are discussed briefly. In particular we focus on physics studies possible with an iron calorimeter detector (ICAL) and the logistics of constructing this detector at INO. Such a detector would make precision measurements of neutrino oscillation parameters with atmospheric neutrinos in the first phase with the possibility of acting as a far-end detector of a future neutrino factory or beta beam.

  7. Effect of dietary protected lipids on the essential fatty acid status of the newborn kid.

    PubMed

    Soares, M C

    1986-08-01

    Pregnant goats were fed either a control diet or one in which part of the concentrate ration was replaced, for either the last 2 mo or the last month of gestation, with a polyunsaturated fatty acid supplement protected from biohydrogenation in the rumen. On the day of parturition, goats fed a supplemented diet, during either 1 or 2 mo before parturition, exhibited markedly higher concentrations of linoleic acid in the major plasma lipid fractions, i.e., phospholipids, cholesteryl esters, triacylglycerols and nonesterified fatty acids, than did goats not fed the supplement. At birth, the four main lipid fractions in the plasma of the kids from goats fed the supplemented diet, during either 1 or 2 mo before parturition, exhibited considerably higher proportions of linoleic and arachidonic acids and lower proportions of eicosatrienoic acid than did those of newborn kids from unsupplemented mothers. These findings show appreciable transfer of lipids across the placenta and demonstrate that the low essential fatty acids status of kids at birth can be raised by this particular manipulation of the maternal diet.

  8. Separation of Acids, Bases, and Neutral Compounds

    NASA Astrophysics Data System (ADS)

    Fujita, Megumi; Mah, Helen M.; Sgarbi, Paulo W. M.; Lall, Manjinder S.; Ly, Tai Wei; Browne, Lois M.

    2003-01-01

    Separation of Acids, Bases, and Neutral Compounds requires the following software, which is available for free download from the Internet: Netscape Navigator, version 4.75 or higher, or Microsoft Internet Explorer, version 5.0 or higher; Chime plug-in, version compatible with your OS and browser (available from MDL); and Flash player, version 5 or higher (available from Macromedia).

  9. Jigsaw Cooperative Learning: Acid-Base Theories

    ERIC Educational Resources Information Center

    Tarhan, Leman; Sesen, Burcin Acar

    2012-01-01

    This study focused on investigating the effectiveness of jigsaw cooperative learning instruction on first-year undergraduates' understanding of acid-base theories. Undergraduates' opinions about jigsaw cooperative learning instruction were also investigated. The participants of this study were 38 first-year undergraduates in chemistry education…

  10. The Magic Sign: Acids, Bases, and Indicators.

    ERIC Educational Resources Information Center

    Phillips, Donald B.

    1986-01-01

    Presents an approach that is used to introduce elementary and junior high students to a series of activities that will provide concrete experiences with acids, bases, and indicators. Provides instructions and listings of needed solutions and materials for developing this "magic sign" device. Includes background information and several student…

  11. Student Concept Changes in Acids and Bases.

    ERIC Educational Resources Information Center

    Ye, Renmin; Wells, Raymond R.

    This study focuses on student concept changes in acids and bases. Variables include field dependent level, personal independence level, interest in science or chemistry, teaching strategy, and student gender. This study of Grade 10 students (N=81) provides information relevant to secondary school chemistry learning, teaching, and concept change.…

  12. Drug-induced acid-base disorders.

    PubMed

    Kitterer, Daniel; Schwab, Matthias; Alscher, M Dominik; Braun, Niko; Latus, Joerg

    2015-09-01

    The incidence of acid-base disorders (ABDs) is high, especially in hospitalized patients. ABDs are often indicators for severe systemic disorders. In everyday clinical practice, analysis of ABDs must be performed in a standardized manner. Highly sensitive diagnostic tools to distinguish the various ABDs include the anion gap and the serum osmolar gap. Drug-induced ABDs can be classified into five different categories in terms of their pathophysiology: (1) metabolic acidosis caused by acid overload, which may occur through accumulation of acids by endogenous (e.g., lactic acidosis by biguanides, propofol-related syndrome) or exogenous (e.g., glycol-dependant drugs, such as diazepam or salicylates) mechanisms or by decreased renal acid excretion (e.g., distal renal tubular acidosis by amphotericin B, nonsteroidal anti-inflammatory drugs, vitamin D); (2) base loss: proximal renal tubular acidosis by drugs (e.g., ifosfamide, aminoglycosides, carbonic anhydrase inhibitors, antiretrovirals, oxaliplatin or cisplatin) in the context of Fanconi syndrome; (3) alkalosis resulting from acid and/or chloride loss by renal (e.g., diuretics, penicillins, aminoglycosides) or extrarenal (e.g., laxative drugs) mechanisms; (4) exogenous bicarbonate loads: milk-alkali syndrome, overshoot alkalosis after bicarbonate therapy or citrate administration; and (5) respiratory acidosis or alkalosis resulting from drug-induced depression of the respiratory center or neuromuscular impairment (e.g., anesthetics, sedatives) or hyperventilation (e.g., salicylates, epinephrine, nicotine).

  13. Regional assessment of the response of the acid-base status of lake watersheds in the Adirondack region of New York to changes in atmospheric deposition using PnET-BGC.

    PubMed

    Chen, Limin; Driscoll, Charles T

    2005-02-01

    Understanding the response of soil and surface waters to changes in atmospheric deposition is critical for guiding future legislation on air pollution. The Adirondack region of New York experiences among the most severe ecological impacts from acidic deposition. The region is characterized by considerable variability in atmospheric deposition, surficial and bedrock geology, hydrologic flow paths, and vegetation resulting in variability in effects of acidic deposition. In this study, an integrated biogeochemical model (PnET-BGC) was applied to 37 forest lake watersheds to assess the response of soil and surface waters of the Adirondacks to changes in atmospheric deposition at a regional scale. Model-simulated surface water chemistry was validated against data from two synoptic surveys conducted in 1984 and 2001. Results indicate that the model is able to capture the observed changes in surface water chemistry during this period. The model was further used to forecast the response of soil and surface waters to three future emission control scenarios. Results indicate that under the Clean Air Act, surface water SO4(2-) concentrations will continue to decrease at a median rate of -0.38 microeq/L-yr, and surface water ANC is predicted to increase at a median rate of 0.11 microeq/L-yr. More aggressive emission reductions will accelerate the rate of recovery. Under an aggressive control scenario, which represents an additional 75% reduction in SO2 emissions beyond the implementation of the Clean Air Act, surface water SO4(2-) concentrations are predicted to decrease at a median rate of -0.88 microeq/L-yr, and surface water ANC is predicted to increase at a median rate of 0.43 microeq/L-yr. Model predictions of several biologically relevant chemical indicators are also reported.

  14. Basal omega-3 fatty acid status affects fatty acid and oxylipin responses to high-dose n3-HUFA in healthy volunteers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: Baseline concentrations of highly unsaturated omega-3 fatty acid (n3-HUFA) may influence the ability of dietary n3-HUFA to affect changes in concentrations of esterified fatty acids and their metabolites. This study evaluates the influence of basal n3-HUFA and n3-HUFA metabolite status ...

  15. The role of photosynthesis and amino acid metabolism in the energy status during seed development.

    PubMed

    Galili, Gad; Avin-Wittenberg, Tamar; Angelovici, Ruthie; Fernie, Alisdair R

    2014-01-01

    Seeds are the major organs responsible for the evolutionary upkeep of angiosperm plants. Seeds accumulate significant amounts of storage compounds used as nutrients and energy reserves during the initial stages of seed germination. The accumulation of storage compounds requires significant amounts of energy, the generation of which can be limited due to reduced penetration of oxygen and light particularly into the inner parts of seeds. In this review, we discuss the adjustment of seed metabolism to limited energy production resulting from the suboptimal penetration of oxygen into the seed tissues. We also discuss the role of photosynthesis during seed development and its contribution to the energy status of developing seeds. Finally, we describe the contribution of amino acid metabolism to the seed energy status, focusing on the Asp-family pathway that leads to the synthesis and catabolism of Lys, Thr, Met, and Ile. PMID:25232362

  16. The role of photosynthesis and amino acid metabolism in the energy status during seed development

    PubMed Central

    Galili, Gad; Avin-Wittenberg, Tamar; Angelovici, Ruthie; Fernie, Alisdair R.

    2014-01-01

    Seeds are the major organs responsible for the evolutionary upkeep of angiosperm plants. Seeds accumulate significant amounts of storage compounds used as nutrients and energy reserves during the initial stages of seed germination. The accumulation of storage compounds requires significant amounts of energy, the generation of which can be limited due to reduced penetration of oxygen and light particularly into the inner parts of seeds. In this review, we discuss the adjustment of seed metabolism to limited energy production resulting from the suboptimal penetration of oxygen into the seed tissues. We also discuss the role of photosynthesis during seed development and its contribution to the energy status of developing seeds. Finally, we describe the contribution of amino acid metabolism to the seed energy status, focusing on the Asp-family pathway that leads to the synthesis and catabolism of Lys, Thr, Met, and Ile. PMID:25232362

  17. Cationic Lipid-Based Nucleic Acid Vectors.

    PubMed

    Jubeli, Emile; Goldring, William P D; Pungente, Michael D

    2016-01-01

    The delivery of nucleic acids into cells remains an important laboratory cell culture technique and potential clinical therapy, based upon the initial cellular uptake, then translation into protein (in the case of DNA), or gene deletion by RNA interference (RNAi). Although viral delivery vectors are more efficient, the high production costs, limited cargo capacity, and the potential for clinical adverse events make nonviral strategies attractive. Cationic lipids are the most widely applied and studied nonviral vectors; however, much remains to be solved to overcome limitations of these systems. Advances in the field of cationic lipid-based nucleic acid (lipoplex) delivery rely upon the development of robust and reproducible lipoplex formulations, together with the use of cell culture assays. This chapter provides detailed protocols towards the formulation, delivery, and assessment of in vitro cationic lipid-based delivery of DNA. PMID:27436310

  18. Acid-based balance and blood gas changes in the fresh water field crab, Barytelphusa guerini, on exposure to organic and inorganic lead

    SciTech Connect

    Tulasi, S.J.; Rao, J.V.R.

    1988-02-01

    The acid-base status of crustacean haemolymph depends on various environmental and physiological factors. Acid base status of the haemolymph is known to be influenced by temperature, salinity, strenuous activity and moulting. The studies on the acid-base regulation of the fresh water crabs are meager. The acid-base changes in fishes during environmental stress conditions like acid stress and zinc toxicity had been reported. But the effect of environmental pollutants like the heavy metals on the acid-base regulation of the fresh water crabs have not been previously reported. The haemolymph of the fresh water crab was found to accumulate high amounts of lead on exposure to organic and inorganic lead. Hence the present investigation has been undertaken to study the haemolymph acid-base status on exposure to subtoxic levels of organic and inorganic lead.

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

    PubMed

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

    2015-08-21

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

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

    PubMed

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

    2015-08-21

    The first hybrid base constructed from 1,8-bis(dimethylamino)naphthalene (proton sponge or DMAN) and glycine, N-methyl-N-(8-dimethylamino-1-naphthyl)aminoacetic acid, was synthesised in high yield and its hydrobromide was structurally characterised and used to determine the acid-base properties via potentiometric titration. It was found that the basic strength of the DMAN-glycine base (pKa = 11.57, H2O) is on the level of amidine amino acids like arginine and creatine and its structure, zwitterionic vs. neutral, based on the spectroscopic (IR, NMR, mass) and theoretical (DFT) approaches has a strong preference to the zwitterionic form. Unlike glycine, the DMAN-glycine zwitterion is N-chiral and is hydrolytically cleaved with the loss of glycolic acid on heating in DMSO. This reaction together with the mild decarboxylative conversion of proton sponge-based amino acids into 2,3-dihydroperimidinium salts under air-oxygen was monitored with the help of the DMAN-alanine amino acid. The newly devised amino acids are unique as they combine fluorescence, strongly basic and redox-active properties. PMID:26159785

  1. A linked spatial and temporal model of the chemical and biological status of a large, acid-sensitive river network.

    PubMed

    Evans, Chris D; Cooper, David M; Juggins, Steve; Jenkins, Alan; Norris, Dave

    2006-07-15

    Freshwater sensitivity to acidification varies according to geology, soils and land-use, and consequently it remains difficult to quantify the current extent of acidification, or its biological impacts, based on limited spot samples. The problem is particularly acute for river systems, where the transition from acid to circum-neutral conditions can occur within short distances. This paper links an established point-based long-term acidification model (MAGIC) with a landscape-based mixing model (PEARLS) to simulate spatial and temporal variations in acidification for a 256 km(2) catchment in North Wales. Empirical relationships are used to predict changes in the probability of occurrence of an indicator invertebrate species, Baetis rhodani, across the catchment as a function of changing chemical status. Results suggest that, at present, 27% of the river network has a mean acid neutralising capacity (ANC) below a biologically-relevant threshold of 20 microeq l(-1). At high flows, this proportion increases to 45%. The model suggests that only around 16% of the stream network had a mean ANC < 20 microeq l(-1) in 1850, but that this increased to 42% at the sulphur deposition peak around 1970. By 2050 recovery is predicted, but with some persistence of acid conditions in the most sensitive, peaty headwaters. Stream chemical suitability for Baetis rhodani is also expected to increase in formerly acidified areas, but for overall abundance to remain below that simulated in 1850. The approach of linking plot-scale process-based models to catchment mixing models provides a potential means of predicting the past and future spatial extent of acidification within large, heterogeneous river networks and regions. Further development of ecological response models to include other chemical predictor variables and the effects of acid episodes would allow more realistic simulation of the temporal and spatial dynamics of ecosystem recovery from acidification.

  2. A linked spatial and temporal model of the chemical and biological status of a large, acid-sensitive river network.

    PubMed

    Evans, Chris D; Cooper, David M; Juggins, Steve; Jenkins, Alan; Norris, Dave

    2006-07-15

    Freshwater sensitivity to acidification varies according to geology, soils and land-use, and consequently it remains difficult to quantify the current extent of acidification, or its biological impacts, based on limited spot samples. The problem is particularly acute for river systems, where the transition from acid to circum-neutral conditions can occur within short distances. This paper links an established point-based long-term acidification model (MAGIC) with a landscape-based mixing model (PEARLS) to simulate spatial and temporal variations in acidification for a 256 km(2) catchment in North Wales. Empirical relationships are used to predict changes in the probability of occurrence of an indicator invertebrate species, Baetis rhodani, across the catchment as a function of changing chemical status. Results suggest that, at present, 27% of the river network has a mean acid neutralising capacity (ANC) below a biologically-relevant threshold of 20 microeq l(-1). At high flows, this proportion increases to 45%. The model suggests that only around 16% of the stream network had a mean ANC < 20 microeq l(-1) in 1850, but that this increased to 42% at the sulphur deposition peak around 1970. By 2050 recovery is predicted, but with some persistence of acid conditions in the most sensitive, peaty headwaters. Stream chemical suitability for Baetis rhodani is also expected to increase in formerly acidified areas, but for overall abundance to remain below that simulated in 1850. The approach of linking plot-scale process-based models to catchment mixing models provides a potential means of predicting the past and future spatial extent of acidification within large, heterogeneous river networks and regions. Further development of ecological response models to include other chemical predictor variables and the effects of acid episodes would allow more realistic simulation of the temporal and spatial dynamics of ecosystem recovery from acidification. PMID:16580046

  3. Chem I Supplement: Emphasis on Acids and Bases

    ERIC Educational Resources Information Center

    Journal of Chemical Education Staff

    1977-01-01

    Provides supplementary notes on acids and bases suitable for secondary school chemistry instruction, including acidity in solid and natural waters, acidity balance in body chemistry, acid and basic foods, pH values of common fluids, examples of drugs, and commercial preparation of nitric acid. (SL)

  4. Beneficial effects of folic acid on enhancement of memory and antioxidant status in aged rat brain.

    PubMed

    Singh, Rashmi; Kanwar, Shalinder S; Sood, Pooja K; Nehru, Bimla

    2011-01-01

    As our population ages, diseases affecting memory and daily functioning will affect an increasing number of individuals, their families and the healthcare system. Therefore, there is a need to study and evaluate effects of certain conditions for anti-aging of the brain. Nutrient supplementation can modify the brain function. The chemistry and function of both the developing and the mature brain are influenced by diet (Fernstrom, Am J Clinical Nutrition 71:1669S-1673S, 2000). Clinical, biochemical, and pathological aspects have shown a correlation between mental symptoms, especially depression and cognitive decline, with high incidence of folate deficiency (Bottiglieri et al., J Neurol Neurosurg Psychiatry 69:562, 2000). In the present study, consequences of folic acid supplementation on brain dysfunction as a result of aging were studied in cerebral cortex, mid brain, and cerebellar regions of rat brain. This study was carried out on 6-, 11-, and 16-month-old rats, which received folic acid at a dose of 5 mg/kg body weight/day for a period of 8 weeks. Respective control groups of the same age groups were also taken. At the end of the treatment duration, behavioral studies were performed and later the animals were killed for various biochemical and histological investigations. Results indicated significant improvement in memory as assessed by active avoidance, passive avoidance, and plus maze tests in the folic acid supplemented aged animals. Significant improvement was also seen in the cellular protective mechanisms where by the activity of superoxide dismutase and catalase enzymes increased in folic acid supplemented group and so was the glutathione content. Increased lipid peroxidation content, a marker of aging, was also found to be decreased during folic acid supplementation in all the three regions of brain in our study. Thus, it can be concluded that folic acid helps in improving the memory status by reducing oxidative stress and maintaining the integrity of

  5. Arsenate exposure affects amino acids, mineral nutrient status and antioxidants in rice (Oryza sativa L.) genotypes.

    PubMed

    Dwivedi, S; Tripathi, R D; Tripathi, P; Kumar, A; Dave, R; Mishra, S; Singh, R; Sharma, D; Rai, U N; Chakrabarty, D; Trivedi, P K; Adhikari, B; Bag, M K; Dhankher, O P; Tuli, R

    2010-12-15

    Simulated pot experiments were conducted on four rice (Oryza sativa L.) genotypes (Triguna, IR-36, PNR-519, and IET-4786) to examine the effects of As(V) on amino acids and mineral nutrient status in grain along with antioxidant response to arsenic exposure. Rice genotypes responded differentially to As(V) exposure in terms of amino acids and antioxidant profiles. Total amino acid content in grains of all rice genotypes was positively correlated with arsenic accumulation. While, most of the essential amino acids increased in all cultivars except IR-36, glutamic acid and glycine increased in IET-4786 and PNR-519. The level of nonprotein thiols (NPTs) and the activities of superoxide dismutase (SOD; EC 1.15.1.1), glutathione reductase (GR; EC 1.6.4.2) and ascorbate peroxidase (APX; EC 1.11.1.11) increased in all rice cultivars except IET-4786. A significant genotypic variation was also observed in specific arsenic uptake (SAU; mg kg(-1)dw), which was in the order of Triguna (134) > IR-36 (71) > PNR-519 (53) > IET-4786 (29). Further, application of As(V) at lower doses (4 and 8 mg L(-1) As) enhanced the accumulation of selenium (Se) and other nutrients (Fe, P, Zn, and S), however, higher dose (12 mg L(-1) As) limits the nutrient uptake in rice. In conclusion, low As accumulating genotype, IET-4786, which also had significantly induced level of essential amino acids, seems suitable for cultivation in moderately As contaminated soil and would be safe for human consumption. PMID:21077666

  6. Impact of fatty acid status on immune function of children in low-income countries.

    PubMed

    Prentice, Andrew M; van der Merwe, Liandré

    2011-04-01

    In vitro and animal studies point to numerous mechanisms by which fatty acids, especially long-chain polyunsaturated fatty acids (LCPUFA), can modulate the innate and adaptive arms of the immune system. These data strongly suggest that improving the fatty acid supply of young children in low-income countries might have immune benefits. Unfortunately, there have been virtually no studies of fatty acid/immune interactions in such settings. Clinical trial registers list over 150 randomized controlled trials (RCTs) involving PUFAs, only one in a low-income setting (the Gambia). We summarize those results here. There was evidence for improved growth and nutritional status, but the primary end point of chronic environmental enteropathy showed no benefit, possibly because the infants were still substantially breastfed. In high-income settings, there have been RCTs with fatty acids (usually LCPUFAs) in relation to 18 disease end points, for some of which there have been numerous trials (asthma, inflammatory bowel disease and rheumatoid arthritis). For these diseases, the evidence is judged reasonable for risk reduction for childhood asthma (but not in adults), as yielding possible benefit in Crohn's disease (insufficient evidence in ulcerative colitis) and for convincing evidence for rheumatoid arthritis at sufficient dose levels, though formal meta-analyses are not yet available. This analysis suggests that fatty acid interventions could yield immune benefits in children in poor settings, especially in non-breastfed children and in relation to inflammatory conditions such as persistent enteropathy. Benefits might include improved responses to enteric vaccines, which frequently perform poorly in low-income settings, and these questions merit randomized trials.

  7. The effects of CT1341, thiopentone and induction- delivery time on the blood gas and acid-base status of lambs delivered by casesarean operation and on the onset of respiration.

    PubMed

    Copland, M D

    1977-09-01

    Caesarean sections were performed on 18 Romney ewes on day 144 of pregnancy. Anaesthesia was induced in 9 ewes with CT 1341 and in 9 ewes with thiopentone and maintained in both groups with halothane administered with oxygen. Surgery was performed with the ewes in lateral recumbency, with respiration unassisted. Blood samples were collected from the intact umbilical artery at the time of delivery and analysed for PO2, PCO2, pH (base deficit was derived). The intervals between ewe induction and lamb delivery (lD), delivery and the onset of breathing (TSR), and delivery and the lamb standing were recorded. Lambs in the CT 1341 group both breathed and stood sooner than lambs in the thiopentone group. Significant linear relationships were only found in the CT 1341 group between TSR interval and PCO2 and pH. No significant correlations were found between the lD interval and any of the biochemical characteristics. The results of this study suggest that lateral recumbency does not interfere with uteroplacental circulation, that CT 1341 (2.2 mg/kg) is associated with less neonatal depression than thiopentone (10 mg/kg) and that severe neonatal hypercarbia may delay the onset of respiration in lambs with minimal drug depression.

  8. Modern quantitative acid-base chemistry.

    PubMed

    Stewart, P A

    1983-12-01

    Quantitative analysis of ionic solutions in terms of physical and chemical principles has been effectively prohibited in the past by the overwhelming amount of calculation it required, but computers have suddenly eliminated that prohibition. The result is an approach to acid-base which revolutionizes our ability to understand, predict, and control what happens to hydrogen ions in living systems. This review outlines that approach and suggests some of its most useful implications. Quantitative understanding requires distinctions between independent variables (in body fluids: pCO2, net strong ion charge, and total weak acid, usually protein), and dependent variables [( HCO-3], [HA], [A-], [CO(2-)3], [OH-], and [H+] (or pH]. Dependent variables are determined by independent variables, and can be calculated from the defining equations for the specific system. Hydrogen ion movements between solutions can not affect hydrogen ion concentration; only changes in independent variables can. Many current models for ion movements through membranes will require modification on the basis of this quantitative analysis. Whole body acid-base balance can be understood quantitatively in terms of the three independent variables and their physiological regulation by the lungs, kidneys, gut, and liver. Quantitative analysis also shows that body fluids interact mainly by strong ion movements through the membranes separating them.

  9. A General Simulator for Acid-Base Titrations

    NASA Astrophysics Data System (ADS)

    de Levie, Robert

    1999-07-01

    General formal expressions are provided to facilitate the automatic computer calculation of acid-base titration curves of arbitrary mixtures of acids, bases, and salts, without and with activity corrections based on the Davies equation. Explicit relations are also given for the buffer strength of mixtures of acids, bases, and salts.

  10. Biotechnological routes based on lactic acid production from biomass.

    PubMed

    Gao, Chao; Ma, Cuiqing; Xu, Ping

    2011-01-01

    Lactic acid, the most important hydroxycarboxylic acid, is now commercially produced by the fermentation of sugars present in biomass. In addition to its use in the synthesis of biodegradable polymers, lactic acid can be regarded as a feedstock for the green chemistry of the future. Different potentially useful chemicals such as pyruvic acid, acrylic acid, 1,2-propanediol, and lactate ester can be produced from lactic acid via chemical and biotechnological routes. Here, we reviewed the current status of the production of potentially valuable chemicals from lactic acid via biotechnological routes. Although some of the reactions described in this review article are still not applicable at current stage, due to their "greener" properties, biotechnological processes for the production of lactic acid derivatives might replace the chemical routes in the future. PMID:21846500

  11. Community-based dental education: history, current status, and future.

    PubMed

    Formicola, Allan J; Bailit, Howard L

    2012-01-01

    This article examines the history, current status, and future direction of community-based dental education (CBDE). The key issues addressed include the reasons that dentistry developed a different clinical education model than the other health professions; how government programs, private medical foundations, and early adopter schools influenced the development of CBDE; the societal and financial factors that are leading more schools to increase the time that senior dental students spend in community programs; the impact of CBDE on school finances and faculty and student perceptions; and the reasons that CBDE is likely to become a core part of the clinical education of all dental graduates.

  12. Ceramic-based fuel technologies: scope and status

    SciTech Connect

    Mcclellan, Kenneth J

    2010-12-16

    This presentation is an overview of the approach, status and path forward for ongoing tasks under the ceramic fuel development part of the program. Experimental work is focused on fundamental studies employing depleted urania-based compositions and mixed oxide (MOX) and minor actinide-bearing MOX. Contributions are included from researchers at LANL, ORNL and BNL. The audience for this presentation consists of the various participants in the FCRD program. Those participants include representatives from: DOE-NE, other national laboratories, DOE funded university researchers, DOE funded industry teams, FCRD funded advisors, and occasionally NRC.

  13. Fatty Acid Composition of Tropical Fish Depends on Reservoir Trophic Status and Fish Feeding Habit.

    PubMed

    Gomes, Aline D; Tolussi, Carlos E; Boëchat, Iola G; Pompêo, Marcelo L M; Cortez, Maíra P T; Honji, Renato M; Moreira, Renata G

    2016-10-01

    Eutrophication results in a deficiency of n-3 LC-PUFA (long-chain polyunsaturated fatty acids) in aquatic food chains, affecting fish nutrition and physiology. The trophic transfer of FA (fatty acids) to fish species of different feeding habits was investigated in two reservoirs in southeast Brazil-the mesotrophic Ponte Nova Reservoir (PN) and the hypereutrophic Billings Reservoir (Bil). Total FA profile of stomach contents and adipose tissue, triacylglycerols (TAG), and phospholipids (PL) from liver and muscle of the omnivorous Astyanax fasciatus and the carnivorous Hoplias malabaricus were analyzed by gas chromatography. A prevalence of n-6PUFA, as 18:2n-6 (linoleic acid) and 20:4n-6 (arachidonic acid, ARA) was observed in the stomach contents and in the tissues of A. fasciatus from the PN reservoir. In contrast, n-3 LC-PUFA, as 20:5n-3 (eicosapentaenoic acid, EPA) was accumulated in fish tissues from Bil, resulting in higher n3/n6 and EPA/ARA ratios, compared to fish from PN. This differential FA accumulation was also observed for H. malabaricus, but differences were slightly minor, and no changes were observed in the EPA/ARA ratios between fish from both reservoirs. Regardless reservoir, FA profiles of TAG resembled that of their diet, whereas FA profiles of PL were more conservative and mainly comprised by LC-PUFA. We conclude that reservoir trophic status affected the FA composition of food resources available to these fish species, resulting in differential allocation of n-3 and n-6 FA. As expected, FA profile of the investigated fish species also reflected their feeding habit and physiological demands.

  14. Fatty Acid Composition of Tropical Fish Depends on Reservoir Trophic Status and Fish Feeding Habit.

    PubMed

    Gomes, Aline D; Tolussi, Carlos E; Boëchat, Iola G; Pompêo, Marcelo L M; Cortez, Maíra P T; Honji, Renato M; Moreira, Renata G

    2016-10-01

    Eutrophication results in a deficiency of n-3 LC-PUFA (long-chain polyunsaturated fatty acids) in aquatic food chains, affecting fish nutrition and physiology. The trophic transfer of FA (fatty acids) to fish species of different feeding habits was investigated in two reservoirs in southeast Brazil-the mesotrophic Ponte Nova Reservoir (PN) and the hypereutrophic Billings Reservoir (Bil). Total FA profile of stomach contents and adipose tissue, triacylglycerols (TAG), and phospholipids (PL) from liver and muscle of the omnivorous Astyanax fasciatus and the carnivorous Hoplias malabaricus were analyzed by gas chromatography. A prevalence of n-6PUFA, as 18:2n-6 (linoleic acid) and 20:4n-6 (arachidonic acid, ARA) was observed in the stomach contents and in the tissues of A. fasciatus from the PN reservoir. In contrast, n-3 LC-PUFA, as 20:5n-3 (eicosapentaenoic acid, EPA) was accumulated in fish tissues from Bil, resulting in higher n3/n6 and EPA/ARA ratios, compared to fish from PN. This differential FA accumulation was also observed for H. malabaricus, but differences were slightly minor, and no changes were observed in the EPA/ARA ratios between fish from both reservoirs. Regardless reservoir, FA profiles of TAG resembled that of their diet, whereas FA profiles of PL were more conservative and mainly comprised by LC-PUFA. We conclude that reservoir trophic status affected the FA composition of food resources available to these fish species, resulting in differential allocation of n-3 and n-6 FA. As expected, FA profile of the investigated fish species also reflected their feeding habit and physiological demands. PMID:27631676

  15. An Introductory Laboratory Exercise for Acids and Bases.

    ERIC Educational Resources Information Center

    Miller, Richard; Silberman, Robert

    1986-01-01

    Discusses an acid-base neutralization exercise requiring groups of students to determine: (1) combinations of solutions giving neutralization; (2) grouping solutions as acids or bases; and (3) ranking groups in order of concentration. (JM)

  16. The Bronsted-Lowery Acid-Base Concept.

    ERIC Educational Resources Information Center

    Kauffman, George B.

    1988-01-01

    Gives the background history of the simultaneous discovery of acid-base relationships by Johannes Bronsted and Thomas Lowry. Provides a brief biographical sketch of each. Discusses their concept of acids and bases in some detail. (CW)

  17. Coronavirus phylogeny based on triplets of nucleic acids bases

    NASA Astrophysics Data System (ADS)

    Liao, Bo; Liu, Yanshu; Li, Renfa; Zhu, Wen

    2006-04-01

    We considered the fully overlapping triplets of nucleotide bases and proposed a 2D graphical representation of protein sequences consisting of 20 amino acids and a stop code. Based on this 2D graphical representation, we outlined a new approach to analyze the phylogenetic relationships of coronaviruses by constructing a covariance matrix. The evolutionary distances are obtained through measuring the differences among the two-dimensional curves.

  18. Mathematical modeling of acid-base physiology

    PubMed Central

    Occhipinti, Rossana; Boron, Walter F.

    2015-01-01

    pH is one of the most important parameters in life, influencing virtually every biological process at the cellular, tissue, and whole-body level. Thus, for cells, it is critical to regulate intracellular pH (pHi) and, for multicellular organisms, to regulate extracellular pH (pHo). pHi regulation depends on the opposing actions of plasma-membrane transporters that tend to increase pHi, and others that tend to decrease pHi. In addition, passive fluxes of uncharged species (e.g., CO2, NH3) and charged species (e.g., HCO3− , NH4+) perturb pHi. These movements not only influence one another, but also perturb the equilibria of a multitude of intracellular and extracellular buffers. Thus, even at the level of a single cell, perturbations in acid-base reactions, diffusion, and transport are so complex that it is impossible to understand them without a quantitative model. Here we summarize some mathematical models developed to shed light onto the complex interconnected events triggered by acids-base movements. We then describe a mathematical model of a spherical cell–which to our knowledge is the first one capable of handling a multitude of buffer reaction–that our team has recently developed to simulate changes in pHi and pHo caused by movements of acid-base equivalents across the plasma membrane of a Xenopus oocyte. Finally, we extend our work to a consideration of the effects of simultaneous CO2 and HCO3− influx into a cell, and envision how future models might extend to other cell types (e.g., erythrocytes) or tissues (e.g., renal proximal-tubule epithelium) important for whole-body pH homeostasis. PMID:25617697

  19. Mathematical modeling of acid-base physiology.

    PubMed

    Occhipinti, Rossana; Boron, Walter F

    2015-01-01

    pH is one of the most important parameters in life, influencing virtually every biological process at the cellular, tissue, and whole-body level. Thus, for cells, it is critical to regulate intracellular pH (pHi) and, for multicellular organisms, to regulate extracellular pH (pHo). pHi regulation depends on the opposing actions of plasma-membrane transporters that tend to increase pHi, and others that tend to decrease pHi. In addition, passive fluxes of uncharged species (e.g., CO2, NH3) and charged species (e.g., HCO3(-), [Formula: see text] ) perturb pHi. These movements not only influence one another, but also perturb the equilibria of a multitude of intracellular and extracellular buffers. Thus, even at the level of a single cell, perturbations in acid-base reactions, diffusion, and transport are so complex that it is impossible to understand them without a quantitative model. Here we summarize some mathematical models developed to shed light onto the complex interconnected events triggered by acids-base movements. We then describe a mathematical model of a spherical cells-which to our knowledge is the first one capable of handling a multitude of buffer reactions-that our team has recently developed to simulate changes in pHi and pHo caused by movements of acid-base equivalents across the plasma membrane of a Xenopus oocyte. Finally, we extend our work to a consideration of the effects of simultaneous CO2 and HCO3(-) influx into a cell, and envision how future models might extend to other cell types (e.g., erythrocytes) or tissues (e.g., renal proximal-tubule epithelium) important for whole-body pH homeostasis.

  20. Bipolar Membranes for Acid Base Flow Batteries

    NASA Astrophysics Data System (ADS)

    Anthamatten, Mitchell; Roddecha, Supacharee; Jorne, Jacob; Coughlan, Anna

    2011-03-01

    Rechargeable batteries can provide grid-scale electricity storage to match power generation with consumption and promote renewable energy sources. Flow batteries offer modular and flexible design, low cost per kWh and high efficiencies. A novel flow battery concept will be presented based on acid-base neutralization where protons (H+) and hydroxyl (OH-) ions react electrochemically to produce water. The large free energy of this highly reversible reaction can be stored chemically, and, upon discharge, can be harvested as usable electricity. The acid-base flow battery concept avoids the use of a sluggish oxygen electrode and utilizes the highly reversible hydrogen electrode, thus eliminating the need for expensive noble metal catalysts. The proposed flow battery is a hybrid of a battery and a fuel cell---hydrogen gas storing chemical energy is produced at one electrode and is immediately consumed at the other electrode. The two electrodes are exposed to low and high pH solutions, and these solutions are separated by a hybrid membrane containing a hybrid cation and anion exchange membrane (CEM/AEM). Membrane design will be discussed, along with ion-transport data for synthesized membranes.

  1. Photocurable bioadhesive based on lactic acid.

    PubMed

    Marques, D S; Santos, J M C; Ferreira, P; Correia, T R; Correia, I J; Gil, M H; Baptista, C M S G

    2016-01-01

    Novel photocurable and low molecular weight oligomers based on l-lactic acid with proven interest to be used as bioadhesive were successfully manufactured. Preparation of lactic acid oligomers with methacrylic end functionalizations was carried out in the absence of catalyst or solvents by self-esterification in two reaction steps: telechelic lactic acid oligomerization with OH end groups and further functionalization with methacrylic anhydride. The final adhesive composition was achieved by the addition of a reported biocompatible photoinitiator (Irgacure® 2959). Preliminary in vitro biodegradability was investigated by hydrolytic degradation in PBS (pH=7.4) at 37 °C. The adhesion performance was evaluated using glued aminated substrates (gelatine pieces) subjected to pull-to-break test. Surface energy measured by contact angles is lower than the reported values of the skin and blood. The absence of cytoxicity was evaluated using human fibroblasts. A notable antimicrobial behaviour was observed using two bacterial models (Staphylococcus aureus and Escherichia coli). The cured material exhibited a strong thrombogenic character when placed in contact with blood, which can be predicted as a haemostatic effect for bleeding control. This novel material was subjected to an extensive characterization showing great potential for bioadhesive or other biomedical applications where biodegradable and biocompatible photocurable materials are required. PMID:26478350

  2. The effect of conjugated linoleic acid supplements on oxidative and antioxidative status of dairy cows.

    PubMed

    Hanschke, N; Kankofer, M; Ruda, L; Höltershinken, M; Meyer, U; Frank, J; Dänicke, S; Rehage, J

    2016-10-01

    Dairy cows develop frequently negative energy balance around parturition and in early lactation, resulting in excessive mobilization of body fat and subsequently in increased risk of ketosis and other diseases. Dietary conjugated linoleic acid (CLA) supplements are used in dairy cows mainly for their depressing effect on milk fat content, but are also proposed to have antioxidative properties. As negative energy balance is associated with oxidative stress, which is also assumed to contribute to disease development, the present study was conducted to examine effects of CLA on oxidative and antioxidative status of lactating dairy cows. German Holstein cows (primiparous n=13, multiparous n=32) were divided into 3 dietary treatment groups receiving 100g/d of control fat supplement, containing 87% stearic acid (CON; n=14), 50g/d of control fat supplement and 50g/d of CLA supplement (CLA 50; n=15), or 100g/d of CLA supplement (CLA 100; n=16). The CLA supplement was lipid-encapsulated and contained 12% of trans-10,cis-12 CLA and cis-9,trans-11 CLA each. Supplementation took place between d1 and 182 postpartum; d 182 until 252 postpartum served as a depletion period. Blood was sampled at d -21, 1, 21, 70, 105, 140, 182, 224, and 252 relative to calving. The antioxidative status was determined using the ferric-reducing ability of plasma, α-tocopherol, α-tocopherol-to-cholesterol mass ratio, and retinol. For determination of oxidative status concentrations of hydroperoxides, thiobarbituric acid-reactive substances (TBARS), N'-formylkynurenine, and bityrosine were measured. Mixed models of fixed and random effects with repeated measures were used to evaluate period 1 (d -21 to 140) and 2 (d182-252) separately. Cows showed increased oxidative stress and lipid peroxidation during the periparturient period in terms of increased serum concentrations of hydroperoxides and TBARS, which decreased throughout lactation. During period 1, the supplemented cows had lower TBARS

  3. The effect of conjugated linoleic acid supplements on oxidative and antioxidative status of dairy cows.

    PubMed

    Hanschke, N; Kankofer, M; Ruda, L; Höltershinken, M; Meyer, U; Frank, J; Dänicke, S; Rehage, J

    2016-10-01

    Dairy cows develop frequently negative energy balance around parturition and in early lactation, resulting in excessive mobilization of body fat and subsequently in increased risk of ketosis and other diseases. Dietary conjugated linoleic acid (CLA) supplements are used in dairy cows mainly for their depressing effect on milk fat content, but are also proposed to have antioxidative properties. As negative energy balance is associated with oxidative stress, which is also assumed to contribute to disease development, the present study was conducted to examine effects of CLA on oxidative and antioxidative status of lactating dairy cows. German Holstein cows (primiparous n=13, multiparous n=32) were divided into 3 dietary treatment groups receiving 100g/d of control fat supplement, containing 87% stearic acid (CON; n=14), 50g/d of control fat supplement and 50g/d of CLA supplement (CLA 50; n=15), or 100g/d of CLA supplement (CLA 100; n=16). The CLA supplement was lipid-encapsulated and contained 12% of trans-10,cis-12 CLA and cis-9,trans-11 CLA each. Supplementation took place between d1 and 182 postpartum; d 182 until 252 postpartum served as a depletion period. Blood was sampled at d -21, 1, 21, 70, 105, 140, 182, 224, and 252 relative to calving. The antioxidative status was determined using the ferric-reducing ability of plasma, α-tocopherol, α-tocopherol-to-cholesterol mass ratio, and retinol. For determination of oxidative status concentrations of hydroperoxides, thiobarbituric acid-reactive substances (TBARS), N'-formylkynurenine, and bityrosine were measured. Mixed models of fixed and random effects with repeated measures were used to evaluate period 1 (d -21 to 140) and 2 (d182-252) separately. Cows showed increased oxidative stress and lipid peroxidation during the periparturient period in terms of increased serum concentrations of hydroperoxides and TBARS, which decreased throughout lactation. During period 1, the supplemented cows had lower TBARS

  4. Using quantitative acid-base analysis in the ICU.

    PubMed

    Lloyd, P; Freebairn, R

    2006-03-01

    The quantitative acid-base 'Strong Ion' calculator is a practical application of quantitative acid-base chemistry, as developed by Peter Stewart and Peter Constable. It quantifies the three independent factors that control acidity, calculates the concentration and charge of unmeasured ions, produces a report based on these calculations and displays a Gamblegram depicting measured ionic species. Used together with the medical history, quantitative acid-base analysis has advantages over traditional approaches.

  5. Teaching Acid/Base Physiology in the Laboratory

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  6. Influence of natural acidity and fisheries management activities upon the status of Adirondack fish populations

    SciTech Connect

    Retzsch, W.C.; Everett, A.G.

    1981-01-01

    Acidification and the disappearance of fish from some Adirondack waters does not appear to be caused solely by acid rain. Acidification is a natural process under certain conditions and precipitation acidified by industrial emissions appears to be only one of many possible causes of pond, lake and stream acidification. Factors other than acid precipitation can cause acidification or reduce fish stocks. As a result of glaciation, northern New York State has hundreds of glacial ponds and lakes, most of which are dystrophic or oligotrophic. Many such waters are located in the western and central portions of the Adirondacks, an area frequently cited as exhibiting the most pronounced effects of acid rain. It is widely recognized that natural unpolluted bogs and peat deposits result in low pH environments. Seasonal and weather conditions also appear to have a substantial effect upon the acidity of peat-bog outflows. An evaluation of recent survey data on critically acidified Adirondack waters indicates that of 192 waters with values less than pH 5.0, approximately 61 percent appear to be directly influenced by natural bog conditions and an additional 14 percent are probably influenced. A review of historical and recent survey data suggest that significant factors, such as natural causes of acidification, low oxygen concentrations, high CO/sub 2/ and H/sub 2/S concentrations, and extreme temperatures may have been ignored or underestimated in evaluating the cause of acidification and fish disappearances in some Adirondack waters. Another factor responsible for the current status of fish stocks in the Adirondacks involves past and present fishery resource management activities.

  7. [Progress in biotransformation of bio-based lactic acid ].

    PubMed

    Gao, Chao; Ma, Cuiqing; Xu, Ping

    2013-10-01

    Fermentative production of lactic acid, an important bio-based chemicals, has made considerable progress. In addition to the food industry and production of polylactic acid, lactic acid also can be used as an important platform chemical for the production of acrylic acid, pyruvic acid, 1,2-propanediol, and lactic acid esters. This article summarizes the recent progress in biocatalytic production of lactic acid derivatives by dehydration, dehydrogenation, reduction, and esterification. Trends in the biotransformation of lactic acid are also discussed. PMID:24432656

  8. Impact of managed moorland burning on peat nutrient and base cation status

    NASA Astrophysics Data System (ADS)

    Palmer, Sheila; Gilpin, Martin; Wearing, Catherine; Johnston, Kerrylyn; Holden, Joseph; Brown, Lee

    2013-04-01

    Controlled 'patch' burning of moorland vegetation has been used for decades in the UK to stimulate growth of heather (Calluna vulgaris) for game bird habitat and livestock grazing. Typically small patches (300-900 m2) are burned in rotations of 8-25 years. However, our understanding of the short-to-medium term environmental impacts of the practice on these sensitive upland areas has so far been limited by a lack of scientific data. In particular the effect of burning on concentrations of base cations and acid-base status of these highly organic soils has implications both for ecosystem nutrient status and for buffering of acidic waters. As part of the EMBER project peat chemistry data were collected in ten upland blanket peat catchments in the UK. Five catchments were subject to a history of prescribed rotational patch burning. The other five catchments acted as controls which were not subject to burning, nor confounded by other detrimental activities such as drainage or forestry. Soil solution chemistry was also monitored at two intensively studied sites (one regularly burned and one control). Fifty-centimetre soil cores, sectioned into 5-cm intervals, were collected from triplicate patches of four burn ages at each burned site, and from twelve locations at similar hillslope positions at each control site. At the two intensively monitored sites, soil solution chemistry was monitored at four depths in each patch. Across all sites, burned plots had significantly smaller cation exchange capacities, lower concentrations of exchangeable base cations and increased concentrations of exchangeable H+ and Al3+ in near-surface soil. C/N ratios were also lower in burned compared to unburned surface soils. There was no consistent trend between burn age and peat chemistry across all burned sites, possibly reflecting local controls on post-burn recovery rates or external influences on burn management decisions. At the intensively monitored site, plots burned less than two years

  9. Lipoprotein(a), essential fatty acid status and lipoprotein lipids in female Australian vegetarians.

    PubMed

    Li, D; Ball, M; Bartlett, M; Sinclair, A

    1999-08-01

    In the present study we investigated serum lipoprotein(a) [Lp(a)] levels, plasma lipids, the serum phospholipid polyunsaturated fatty acid profile and correlates of serum Lp(a) in healthy free-living female vegetarians (n=50) and omnivores (n=24) to assess differences which may have implications for cardiovascular risk. Dietary saturated fat and total plasma cholesterol were significantly lower in the vegetarians compared with omnivores. The mean serum Lp(a) concentration was lower in the vegetarians (171 mg/l) than in the omnivores (247 mg/l). The serum Lp(a) concentration was significantly negatively correlated with carbohydrate intake (as % of energy), and positively correlated with plasma total cholesterol. Compared with the omnivores, the vegetarians had significantly lower concentrations of 20:3,n-6, 20:4,n-6, 22:5,n-6, 20:5,n-3, 22:6,n-3 and total n-6 and n-3 polyunsaturated fatty acids, and a lower n-3/n-6 polyunsaturated fatty acid ratio, in serum phospholipids. Lower concentrations of plasma total cholesterol, serum phospholipid total fatty acids, total saturated fatty acids and arachidonic acid, and a tendency towards a lower serum Lp(a) concentration, in vegetarians may have beneficial effects on cardiovascular disease risk. However, the decreased concentration of serum phospholipid n-3 polyunsaturated fatty acids may potentially promote thrombotic risk. Based on the present data, it would seem appropriate for omnivores to reduce their dietary intake of total fat and saturated fat in order to decrease their plasma cholesterol, and vegetarians should perhaps increase their dietary intake of n-3 polyunsaturated fatty acids, and thus improve the balance of n-3/n-6, in order to reduce any thrombotic tendency that might increase their generally low risk of cardiovascular disease.

  10. Identifying a base in a nucleic acid

    DOEpatents

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2005-02-08

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  11. The influence of total organic carbon (TOC) on the relationship between acid neutralizing capacity (ANC) and fish status in Norwegian lakes.

    PubMed

    Lydersen, Espen; Larssen, Thorjørn; Fjeld, Eirik

    2004-06-29

    Acid neutralizing capacity (ANC) is the parameter most commonly used as chemical indicator for fish response to acidification. Empirical relationships between fish status of surface waters and ANC have been documented earlier. ANC is commonly calculated as the difference between base cations ([BC]=[Ca2+]+[Mg2+]+[N+]+[K+]) and strong acid anions ([SAA]=[SO4(2)-]+[NO3-]+[Cl-]). This is a very robust calculation of ANC, because none of the parameters incorporated are affected by the partial pressure of CO2, in contrast to the remaining major ions in waters, pH ([H+]), aluminum ([Aln+]), alkalinity ([HCO3-/CO3(2)-]) and organic anions ([An-]). Here we propose a modified ANC calculation where the permanent anionic charge of the organic acids is assumed as a part of the strong acid anions. In many humic lakes, the weak organic acids are the predominant pH-buffering system. Because a significant amount of the weak organic acids have pK-values<3.0-3.5, these relatively strong acids will permanently be deprotonated in almost all natural waters (i.e. pH>4.5). This means that they will be permanently present as anions, equal to the strong acid inorganic anions, SO4(2)-, NO3- and Cl-. In the literature, natural organic acids are often described as triprotic acids with a low pK1 value. Assuming a triprotic model, we suggest to add 1/3 of the organic acid charge density to the strong acid anions in the ANC calculation. The suggested organic acid adjusted ANC (ANC(OAA)), is then calculated as follows: ANC(OAA)=[BC]-([SAA]+1/3CD*TOC) where TOC is total organic carbon (mg C L(-1)), and CD=10.2 is charge density of the organic matter (microeq/mg C), based on literature data from Swedish lakes. ANC(OAA) gives significant lower values of ANC in order to achieve equal fish status compared with the traditional ANC calculation. Using ANC(OAA) the humic conditions in lakes are better taken into account. This may also help explain observations of higher ANC needed to have reproducing fish

  12. Impact of the diet on net endogenous acid production and acid-base balance.

    PubMed

    Poupin, Nathalie; Calvez, Juliane; Lassale, Camille; Chesneau, Caroline; Tomé, Daniel

    2012-06-01

    Net acid production, which is composed of volatile acids (15,000 mEq/day) and metabolic acids (70-100 mEq/day) is relatively small compared to whole-body H⁺ turnover (150,000 mEq/day). Metabolic acids are ingested from the diet or produced as intermediary or end products of endogenous metabolism. The three commonly reported sources of net acid production are the metabolism of sulphur amino acids, the metabolism or ingestion of organic acids, and the metabolism of phosphate esters or dietary phosphoproteins. Net base production occurs mainly as a result of absorption of organic anions from the diet. To maintain acid-base balance, ingested and endogenously produced acids are neutralized within the body by buffer systems or eliminated from the body through the respiratory (excretion of volatile acid in the form of CO₂) and urinary (excretion of fixed acids and remaining H⁺) pathways. Because of the many reactions involved in the acid-base balance, the direct determination of acid production is complex and is usually estimated through direct or indirect measurements of acid excretion. However, indirect approaches, which assess the acid-forming potential of the ingested diet based on its composition, do not take all the acid-producing reactions into account. Direct measurements therefore seem more reliable. Nevertheless, acid excretion does not truly provide information on the way acidity is dealt with in the plasma and this measurement should be interpreted with caution when assessing acid-base imbalance.

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

    PubMed

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

    2014-12-01

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

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

    PubMed

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

    2014-12-01

    Hydrofluoric acid (HF), a dangerous inorganic acid, can cause severe corrosive effects and systemic toxicity. HF enters the human body via where it contacts, such as skin and mucosa, alimentary and respiratory tracts, and ocular surfaces. In the recent years, the incidence of HF burn has tended to increase over time. The injury mechanism of HF is associated primarily with the massive absorption of HF and the release of hydrogen ions. Correct diagnosis and timely treatment are especially important for HF burns. The critical procedure to treat HF burn is to prevent on-going HF absorption, and block the progressive destruction caused by fluoride ions. Due to the distinct characteristics of HF burns, the topical treatment, as well as systemic support, has been emphasised. Whereas, management of patients with HF burns remains a great challenge in some situations. To date, there has been no widely accepted protocol for the rescue of HF burns, partly due to the diversity of HF burns. This paper overviews the current status and problems of treatment strategies for HF burns, for the purpose of promoting the future researches and improvement. PMID:24946967

  15. Antigen-based immunotherapy for autoimmune disease: current status

    PubMed Central

    Hirsch, Darren Lowell; Ponda, Punita

    2015-01-01

    Autoimmune diseases are common chronic disorders that not only have a major impact on the quality of life but are also potentially life-threatening. Treatment modalities that are currently favored have conferred significant clinical benefits, but they may have considerable side effects. An optimal treatment strategy for autoimmune disease would specifically target disease-associated antigens and limit systemic side effects. Similar to allergen-specific immunotherapy for allergic rhinitis, antigen-specific immunotherapy for autoimmune disease aims to induce immune deviation and promote tolerance to specific antigens. In this review, we present the current status of studies and clinical trials in both human and animal hosts that use antigen-based immunotherapy for autoimmune disease. PMID:27471707

  16. A cross-sectional study of docosahexaenoic acid status and cognitive outcomes in females of reproductive age with phenylketonuria.

    PubMed

    Yi, Sarah H L; Kable, Julie A; Evatt, Marian L; Singh, Rani H

    2011-04-01

    Diet therapy for phenylketonuria (PKU) requires restricted phenylalanine (Phe) intake, with the majority of protein and other nutrients coming from synthetic medical food. The fatty acid docosahexaenoic acid (DHA) is important in brain development and function; however, there are reports of low blood DHA concentrations in people treated for PKU. Although the implications of this low blood DHA are unclear, subtle cognitive deficits have been reported in those treated early and continuously for PKU. For this study, we investigated the relationship between DHA status and cognitive performance in 41 females 12 years and older with PKU. Participants were attending the baseline visit of a research-based camp or a supplementation trial. We assessed the domains of verbal ability, processing speed, and executive function using standardized tests, and the proportions of DHA in plasma and red blood cell (RBC) total lipids using gas chromatography/mass spectrometry. Percent plasma and RBC total lipid DHA were significantly lower in the participants compared with laboratory controls (P < .001), and participants consumed no appreciable DHA according to diet records. Plasma and RBC DHA both negatively correlated with plasma Phe (P < .02), and performance on the verbal ability task positively correlated with RBC DHA controlling for plasma Phe (R = .32, P = .03). The relationship between DHA and domains related to verbal ability, such as learning and memory, should be confirmed in a controlled trial. Domains of processing speed and executive function may require a larger sample size to clarify any association with DHA. PMID:21305356

  17. Soil calcium status and the response of stream chemistry to changing acidic deposition rates

    USGS Publications Warehouse

    Lawrence, G.B.; David, M.B.; Lovett, Gary M.; Murdoch, Peter S.; Burns, Douglas A.; Stoddard, J.L.; Baldigo, Barry P.; Porter, J.H.; Thompson, A.W.

    1999-01-01

    Despite a decreasing trend in acidic deposition rates over the past two to three decades, acidified surface waters in the northeastern United States have shown minimal changes. Depletion of soil Ca pools has been suggested as a cause, although changes in soil Ca pools have not been directly related to long-term records of stream chemistry. To investigate this problem, a comprehensive watershed study was conducted in the Neversink River Basin, in the Catskill Mountains of New York, during 1991-1996. Spatial variations of atmospheric deposition, soil chemistry, and stream chemistry were evaluated over an elevation range of 817-1234 m to determine whether these factors exhibited elevational patterns. An increase in atmospheric deposition of SO4 with increasing elevation corresponded with upslope decreases of exchangeable soil base concentrations and acid-neutralizing capacity of stream water. Exchangeable base concentrations in homogeneous soil incubated within the soil profile for one year also decreased with increasing elevation. An elevational gradient in precipitation was not observed, and effects of a temperature gradient on soil properties were not detected. Laboratory leaching experiments with soils from this watershed showed that (1) concentrations of Ca in leachate increased as the concentrations of acid anions in added solution increased, and (2) the slope of this relationship was positively correlated with base saturation. Field and laboratory soil analyses are consistent with the interpretation that decreasing trends in acid-neutralizing capacity in stream water in the Neversink Basin, dating back to 1984, are the result of decreases in soil base saturation caused by acidic deposition.

  18. Polymer gel dosimeter based on itaconic acid.

    PubMed

    Mattea, Facundo; Chacón, David; Vedelago, José; Valente, Mauro; Strumia, Miriam C

    2015-11-01

    A new polymeric dosimeter based on itaconic acid and N, N'-methylenebisacrylamide was studied. The preparation method, compositions of monomer and crosslinking agent and the presence of oxygen in the dosimetric system were analyzed. The resulting materials were irradiated with an X-ray tube at 158cGy/min, 226cGymin and 298cGy/min with doses up to 1000Gy. The dosimeters presented a linear response in the dose range 75-1000Gy, sensitivities of 0.037 1/Gyat 298cGy/min and an increase in the sensitivity with lower dose rates. One of the most relevant outcomes in this study was obtaining different monomer to crosslinker inclusion in the formed gel for the dosimeters where oxygen was purged during the preparation method. This effect has not been reported in other typical dosimeters and could be attributed to the large differences in the reactivity among these species.

  19. On the acid-base properties of humic acid in soil.

    PubMed

    Cooke, James D; Hamilton-Taylor, John; Tipping, Edward

    2007-01-15

    Humic acid was isolated from three contrasting organic-rich soils and acid-base titrations performed over a range of ionic strengths. Results obtained were unlike most humic acid data sets; they showed a greater ionic strength dependency at low pH than at high pH. Forward- and back-titrations with the base and acid revealed hysteresis, particularly at low pH. Previous authors attributed this type of hysteresis to humic acid aggregates-created during the isolation procedure-being redissolved during titration as the pH increased and regarded the results as artificial. However, forward- and back-titrations with organic-rich soils also demonstrated a similar hysteretic behavior. These observations indicate (i) that titrations of humic acid in aggregated form (as opposed to the more usual dissolved form) are more representative of the acid-base properties of humic acid in soil and (ii) that the ionic strength dependency of proton binding in humic acid is related to its degree of aggregation. Thus, the current use of models based on data from dissolved humic substances to predictthe acid-base properties of humic acid in soil under environmental conditions may be flawed and could substantially overestimate their acid buffering capacity.

  20. Atenolol offers better protection than clonidine against cardiac injury in kainic acid-induced status epilepticus

    PubMed Central

    Read, M I; Harrison, J C; Kerr, D S; Sammut, I A

    2015-01-01

    Background and Purpose Status epilepticus is increasingly associated with cardiac injury in both clinical and animal studies. The current study examined ECG activity for up to 48 h following kainic acid (KA) seizure induction and compared the potential of atenolol and clonidine to attenuate this cardiac pathology. Experimental Approach Sprague-Dawley rats (male, 300–350 g) were implanted with ECG and electrocorticogram electrodes to allow simultaneous telemetric recordings of cardiac and cortical responses during and after KA-induced seizures. Animals were randomized into saline controls, and saline vehicle-, clonidine- or atenolol-pretreated KA groups. Key Results KA administration in the saline-pretreated group produced an immediate bradycardic response (maximal decrease of 28 ± 6%), coinciding with low-level seizure activity. As high-level seizure behaviours and EEG spiking increased, tachycardia also developed, with a maximum heart rate increase of 38 ± 7% coinciding with QTc prolongation and T wave elevation. Both clonidine and atenolol pretreatment attenuated seizure activity and reduced KA-induced changes in heart rate, QTc interval and T wave amplitude observed during both bradycardic and tachycardic phases in saline-pretreated KA animals. Clonidine, however, failed to reduce the power of EEG frequencies. Atenolol and to a lesser extent clonidine attenuated the cardiac hypercontraction band necrosis, inflammatory infiltration, and oedema at 48 h after KA, relative to the saline-KA group. Conclusions and Implications Severe seizure activity in this model was clearly associated with altered ECG activity and cardiac pathology. We suggest that modulation of sympathetic activity by atenolol provides a promising cardioprotective approach in status epilepticus. PMID:25765931

  1. Renal acid-base metabolism after ischemia.

    PubMed

    Holloway, J C; Phifer, T; Henderson, R; Welbourne, T C

    1986-05-01

    The response of the kidney to ischemia-induced cellular acidosis was followed over the immediate one hr post-ischemia reflow period. Clearance and extraction experiments as well as measurement of cortical intracellular pH (pHi) were performed on Inactin-anesthetized Sprague-Dawley rats. Arteriovenous concentration differences and para-aminohippurate extraction were obtained by cannulating the left renal vein. Base production was monitored as bicarbonate released into the renal vein and urine; net base production was related to the renal handling of glutamine and ammonia as well as to renal oxygen consumption and pHi. After a 15 min control period, the left renal artery was snared for one-half hr followed by release and four consecutive 15 min reflow periods. During the control period, cortical cell pHi measured by [14C]-5,5-Dimethyl-2,4-Oxazolidinedione distribution was 7.07 +/- 0.08, and Q-O2 was 14.1 +/- 2.2 micromoles/min; neither net glutamine utilization nor net bicarbonate generation occurred. After 30 min of ischemia, renal tissue pH fell to 6.6 +/- 0.15. However, within 45 min of reflow, cortical cell pH returned and exceeded the control value, 7.33 +/- 0.06 vs. 7.15 +/- 0.08. This increase in pHi was associated with a significant rise in cellular metabolic rate, Q-O2 increased to 20.3 +/- 6.4 micromoles/min. Corresponding with cellular alkalosis was a net production of bicarbonate and a net ammonia uptake and glutamine release; urinary acidification was abolished. These results are consistent with a nonexcretory renal metabolic base generating mechanism governing cellular acid base homeostasis following ischemia. PMID:3723929

  2. Community based mangrove management: a review on status and sustainability.

    PubMed

    Datta, Debajit; Chattopadhyay, R N; Guha, P

    2012-09-30

    Community Based Mangrove Management (CBMM) has been advocated by both academia and governing agencies as a viable alternative for sustainably managing the ecologically important mangrove forests which are disappearing rapidly worldwide. Drawing insights from diverse sustainability issues, capabilities and performances of worldwide CBMM initiatives were examined in this paper. Higher numbers of CBMM initiatives were reported from South Asia and lesser from South America and Africa. Identification of the causes of degradation at a site and use-specific zonal replantations with respect to species associations were identified as major criteria of ecological sustainability. Regarding economic sustainability, transformation of potential uses of mangroves known by local communities into actual ones was found to be necessary. Proper disbursement of accrued benefits among community members irrespective of their socio-cultural status is also a major concern. Restructuring of CBMM institutions by ensuring participation of subsistence based users in decision-making and resource sharing have been identified as a prime determinant of institutional sustainability. However, limited number of studies on socio-political and institutional aspects as well as impacts of globalization induced socio-cultural transformations of communities on CBMM had been actually found. More focused researches on these aspects had been recommended for better community management of these highly stressed forests. PMID:22595074

  3. Anthocyanins do not influence long-chain n-3 fatty acid status: studies in cells, rodents and humans☆

    PubMed Central

    Vauzour, David; Tejera, Noemi; O'Neill, Colette; Booz, Valeria; Jude, Baptiste; Wolf, Insa M.A.; Rigby, Neil; Silvan, Jose Manuel; Curtis, Peter J.; Cassidy, Aedin; de Pascual-Teresa, Sonia; Rimbach, Gerald; Minihane, Anne Marie

    2015-01-01

    Increased tissue status of the long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular and cognitive benefits. Limited epidemiological and animal data suggest that flavonoids, and specifically anthocyanins, may increase EPA and DHA levels, potentially by increasing their synthesis from the shorter-chain n-3 PUFA, α-linolenic acid. Using complimentary cell, rodent and human studies we investigated the impact of anthocyanins and anthocyanin-rich foods/extracts on plasma and tissue EPA and DHA levels and on the expression of fatty acid desaturase 2 (FADS2), which represents the rate limiting enzymes in EPA and DHA synthesis. In experiment 1, rats were fed a standard diet containing either palm oil or rapeseed oil supplemented with pure anthocyanins for 8 weeks. Retrospective fatty acid analysis was conducted on plasma samples collected from a human randomized controlled trial where participants consumed an elderberry extract for 12 weeks (experiment 2). HepG2 cells were cultured with α-linolenic acid with or without select anthocyanins and their in vivo metabolites for 24 h and 48 h (experiment 3). The fatty acid composition of the cell membranes, plasma and liver tissues were analyzed by gas chromatography. Anthocyanins and anthocyanin-rich food intake had no significant impact on EPA or DHA status or FADS2 gene expression in any model system. These data indicate little impact of dietary anthocyanins on n-3 PUFA distribution and suggest that the increasingly recognized benefits of anthocyanins are unlikely to be the result of a beneficial impact on tissue fatty acid status. PMID:25573539

  4. Anthocyanins do not influence long-chain n-3 fatty acid status: studies in cells, rodents and humans.

    PubMed

    Vauzour, David; Tejera, Noemi; O'Neill, Colette; Booz, Valeria; Jude, Baptiste; Wolf, Insa M A; Rigby, Neil; Silvan, Jose Manuel; Curtis, Peter J; Cassidy, Aedin; de Pascual-Teresa, Sonia; Rimbach, Gerald; Minihane, Anne Marie

    2015-03-01

    Increased tissue status of the long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) is associated with cardiovascular and cognitive benefits. Limited epidemiological and animal data suggest that flavonoids, and specifically anthocyanins, may increase EPA and DHA levels, potentially by increasing their synthesis from the shorter-chain n-3 PUFA, α-linolenic acid. Using complimentary cell, rodent and human studies we investigated the impact of anthocyanins and anthocyanin-rich foods/extracts on plasma and tissue EPA and DHA levels and on the expression of fatty acid desaturase 2 (FADS2), which represents the rate limiting enzymes in EPA and DHA synthesis. In experiment 1, rats were fed a standard diet containing either palm oil or rapeseed oil supplemented with pure anthocyanins for 8 weeks. Retrospective fatty acid analysis was conducted on plasma samples collected from a human randomized controlled trial where participants consumed an elderberry extract for 12 weeks (experiment 2). HepG2 cells were cultured with α-linolenic acid with or without select anthocyanins and their in vivo metabolites for 24 h and 48 h (experiment 3). The fatty acid composition of the cell membranes, plasma and liver tissues were analyzed by gas chromatography. Anthocyanins and anthocyanin-rich food intake had no significant impact on EPA or DHA status or FADS2 gene expression in any model system. These data indicate little impact of dietary anthocyanins on n-3 PUFA distribution and suggest that the increasingly recognized benefits of anthocyanins are unlikely to be the result of a beneficial impact on tissue fatty acid status.

  5. Base pairing and base mis-pairing in nucleic acids

    NASA Technical Reports Server (NTRS)

    Wang, A. H. J.; Rich, A.

    1986-01-01

    In recent years we have learned that DNA is conformationally active. It can exist in a number of different stable conformations including both right-handed and left-handed forms. Using single crystal X-ray diffraction analysis we are able to discover not only additional conformations of the nucleic acids but also different types of hydrogen bonded base-base interactions. Although Watson-Crick base pairings are the predominant type of interaction in double helical DNA, they are not the only types. Recently, we have been able to examine mismatching of guanine-thymine base pairs in left-handed Z-DNA at atomic resolution (1A). A minimum amount of distortion of the sugar phosphate backbone is found in the G x T pairing in which the bases are held together by two hydrogen bonds in the wobble pairing interaction. Because of the high resolution of the analysis we can visualize water molecules which fill in to accommodate the other hydrogen bonding positions in the bases which are not used in the base-base interactions. Studies on other DNA oligomers have revealed that other types of non-Watson-Crick hydrogen bonding interactions can occur. In the structure of a DNA octamer with the sequence d(GCGTACGC) complexed to an antibiotic triostin A, it was found that the two central AT base pairs are held together by Hoogsteen rather than Watson-Crick base pairs. Similarly, the G x C base pairs at the ends are also Hoogsteen rather than Watson-Crick pairing. Hoogsteen base pairs make a modified helix which is distinct from the Watson-Crick double helix.

  6. Multi-omics profile of the mouse dentate gyrus after kainic acid-induced status epilepticus.

    PubMed

    Schouten, Marijn; Bielefeld, Pascal; Fratantoni, Silvina A; Hubens, Chantal J; Piersma, Sander R; Pham, Thang V; Voskuyl, Rob A; Lucassen, Paul J; Jimenez, Connie R; Fitzsimons, Carlos P

    2016-01-01

    Temporal lobe epilepsy (TLE) can develop from alterations in hippocampal structure and circuit characteristics, and can be modeled in mice by administration of kainic acid (KA). Adult neurogenesis in the dentate gyrus (DG) contributes to hippocampal functions and has been reported to contribute to the development of TLE. Some of the phenotypical changes include neural stem and precursor cells (NPSC) apoptosis, shortly after their birth, before they produce hippocampal neurons. Here we explored these early phenotypical changes in the DG 3 days after a systemic injection of KA inducing status epilepticus (KA-SE), in mice. We performed a multi-omics experimental setup and analyzed DG tissue samples using proteomics, transcriptomics and microRNA profiling techniques, detecting the expression of 2327 proteins, 13401 mRNAs and 311 microRNAs. We here present a description of how these data were obtained and make them available for further analysis and validation. Our data may help to further identify and characterize molecular mechanisms involved in the alterations induced shortly after KA-SE in the mouse DG. PMID:27529540

  7. Myoinositol Attenuates the Cell Loss and Biochemical Changes Induced by Kainic Acid Status Epilepticus

    PubMed Central

    Kikvidze, Marina

    2016-01-01

    Identification of compounds preventing or modifying the biochemical changes that underlie the epileptogenesis process and understanding the mechanism of their action are of great importance. We have previously shown that myoinositol (MI) daily treatment for 28 days prevents certain biochemical changes that are triggered by kainic acid (KA) induced status epilepticus (SE). However in these studies we have not detected any effects of MI on the first day after SE. In the present study we broadened our research and focused on other molecular and morphological changes at the early stages of SE induced by KA and effects of MI treatment on these changes. The increase in the amount of voltage-dependent anionic channel-1 (VDAC-1), cofilin, and caspase-3 activity was observed in the hippocampus of KA treated rats. Administration of MI 4 hours later after KA treatment abolishes these changes, whereas diazepam treatment by the same time schedule has no significant influence. The number of neuronal cells in CA1 and CA3 subfields of hippocampus is decreased after KA induced SE and MI posttreatment significantly attenuates this reduction. No significant changes are observed in the neocortex. Obtained results indicate that MI posttreatment after KA induced SE could successfully target the biochemical processes involved in apoptosis, reduces cell loss, and can be successfully used in the future for translational research.

  8. Myoinositol Attenuates the Cell Loss and Biochemical Changes Induced by Kainic Acid Status Epilepticus

    PubMed Central

    Kikvidze, Marina

    2016-01-01

    Identification of compounds preventing or modifying the biochemical changes that underlie the epileptogenesis process and understanding the mechanism of their action are of great importance. We have previously shown that myoinositol (MI) daily treatment for 28 days prevents certain biochemical changes that are triggered by kainic acid (KA) induced status epilepticus (SE). However in these studies we have not detected any effects of MI on the first day after SE. In the present study we broadened our research and focused on other molecular and morphological changes at the early stages of SE induced by KA and effects of MI treatment on these changes. The increase in the amount of voltage-dependent anionic channel-1 (VDAC-1), cofilin, and caspase-3 activity was observed in the hippocampus of KA treated rats. Administration of MI 4 hours later after KA treatment abolishes these changes, whereas diazepam treatment by the same time schedule has no significant influence. The number of neuronal cells in CA1 and CA3 subfields of hippocampus is decreased after KA induced SE and MI posttreatment significantly attenuates this reduction. No significant changes are observed in the neocortex. Obtained results indicate that MI posttreatment after KA induced SE could successfully target the biochemical processes involved in apoptosis, reduces cell loss, and can be successfully used in the future for translational research. PMID:27642592

  9. Myoinositol Attenuates the Cell Loss and Biochemical Changes Induced by Kainic Acid Status Epilepticus.

    PubMed

    Tsverava, Lia; Lordkipanidze, Tamar; Lepsveridze, Eka; Nozadze, Maia; Kikvidze, Marina; Solomonia, Revaz

    2016-01-01

    Identification of compounds preventing or modifying the biochemical changes that underlie the epileptogenesis process and understanding the mechanism of their action are of great importance. We have previously shown that myoinositol (MI) daily treatment for 28 days prevents certain biochemical changes that are triggered by kainic acid (KA) induced status epilepticus (SE). However in these studies we have not detected any effects of MI on the first day after SE. In the present study we broadened our research and focused on other molecular and morphological changes at the early stages of SE induced by KA and effects of MI treatment on these changes. The increase in the amount of voltage-dependent anionic channel-1 (VDAC-1), cofilin, and caspase-3 activity was observed in the hippocampus of KA treated rats. Administration of MI 4 hours later after KA treatment abolishes these changes, whereas diazepam treatment by the same time schedule has no significant influence. The number of neuronal cells in CA1 and CA3 subfields of hippocampus is decreased after KA induced SE and MI posttreatment significantly attenuates this reduction. No significant changes are observed in the neocortex. Obtained results indicate that MI posttreatment after KA induced SE could successfully target the biochemical processes involved in apoptosis, reduces cell loss, and can be successfully used in the future for translational research. PMID:27642592

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

    PubMed

    Sabilallah, Mounira; Fontanaud, Pierre; Linck, Nathalie; Boussadia, Badreddine; Peyroutou, Ronan; Lasgouzes, Thibault; Rassendren, François A; Marchi, Nicola; Hirbec, Helene E

    2016-01-01

    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. PMID:26963100

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

    PubMed Central

    Sabilallah, Mounira; Fontanaud, Pierre; Linck, Nathalie; Boussadia, Badreddine; Peyroutou, Ronan; Lasgouzes, Thibault; Rassendren, François A.

    2016-01-01

    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. PMID:26963100

  12. Multi-omics profile of the mouse dentate gyrus after kainic acid-induced status epilepticus

    PubMed Central

    Schouten, Marijn; Bielefeld, Pascal; Fratantoni, Silvina A.; Hubens, Chantal J.; Piersma, Sander R.; Pham, Thang V.; Voskuyl, Rob A.; Lucassen, Paul J.; Jimenez, Connie R.; Fitzsimons, Carlos P.

    2016-01-01

    Temporal lobe epilepsy (TLE) can develop from alterations in hippocampal structure and circuit characteristics, and can be modeled in mice by administration of kainic acid (KA). Adult neurogenesis in the dentate gyrus (DG) contributes to hippocampal functions and has been reported to contribute to the development of TLE. Some of the phenotypical changes include neural stem and precursor cells (NPSC) apoptosis, shortly after their birth, before they produce hippocampal neurons. Here we explored these early phenotypical changes in the DG 3 days after a systemic injection of KA inducing status epilepticus (KA-SE), in mice. We performed a multi-omics experimental setup and analyzed DG tissue samples using proteomics, transcriptomics and microRNA profiling techniques, detecting the expression of 2327 proteins, 13401 mRNAs and 311 microRNAs. We here present a description of how these data were obtained and make them available for further analysis and validation. Our data may help to further identify and characterize molecular mechanisms involved in the alterations induced shortly after KA-SE in the mouse DG. PMID:27529540

  13. The status of the passive treatment systems for acid mine drainage in South Korea

    NASA Astrophysics Data System (ADS)

    Ji, Sangwoo; Kim, Sunjoon; Ko, Juin

    2008-09-01

    This study was performed to investigate the operating status, evaluate the problems, and discuss possible improvement methods of passive treatment systems for acid mine drainage (AMD) in South Korea. Thirty-five passive treatment systems in 29 mines have been constructed from 1996 to 2002 using successive alkalinity producing systems (SAPS) as the main treatment process. We investigated 29 systems (two for metal mines), 19 of which revealed various problems. Overflows of drainage from SAPS, wetland, or oxidation ponds were caused by the flow rate exceeding the capacities of the facilities or by the reduced permeability of the organic substance layer. Leakages occurred at various parts of the systems. In some cases, clogged and broken pipes at the mouths of the mine adits made the whole system unusable. Some systems showed very low efficiencies without apparent leakage or overflow. Even though the systems showed fairly good efficiencies in metal removal ratios (mainly iron) and pH control; sulfate removal rates were very poor except in three systems, which may indicate very poor sulfate reductions with sulfate reducing bacteria (SRB) as a means.

  14. Temperature and acid-base balance in the American lobster Homarus americanus.

    PubMed

    Qadri, Syed Aman; Camacho, Joseph; Wang, Hongkun; Taylor, Josi R; Grosell, Martin; Worden, Mary Kate

    2007-04-01

    Lobsters (Homarus americanus) in the wild inhabit ocean waters where temperature can vary over a broad range (0-25 degrees C). To examine how environmental thermal variability might affect lobster physiology, we examine the effects of temperature and thermal change on the acid-base status of the lobster hemolymph. Total CO(2), pH, P(CO)2 and HCO(-)(3) were measured in hemolymph sampled from lobsters acclimated to temperature in the laboratory as well as from lobsters acclimated to seasonal temperatures in the wild. Our results demonstrate that the change in hemolymph pH as a function of temperature follows the rule of constant relative alkalinity in lobsters acclimated to temperature over a period of weeks. However, thermal change can alter lobster acid-base status over a time course of minutes. Acute increases in temperature trigger a respiratory compensated metabolic acidosis of the hemolymph. Both the strength and frequency of the lobster heartbeat in vitro are modulated by changes in pH within the physiological range measured in vivo. These observations suggest that changes in acid-base status triggered by thermal variations in the environment might modulate lobster cardiac performance in vivo.

  15. Consumption of folic acid-fortified bread improves folate status in women of reproductive age in Chile.

    PubMed

    Hertrampf, Eva; Cortés, Fanny; Erickson, J David; Cayazzo, Marisol; Freire, Wilma; Bailey, Lynn B; Howson, Christopher; Kauwell, Gail P A; Pfeiffer, Christine

    2003-10-01

    Since January 2000 the Chilean Ministry of Health has required the fortification of wheat flour with folic acid (FA) at a concentration of 2.2 mg FA/kg in order to reduce the risk of neural tube defects (NTD) in newborns. This policy was expected to result in a mean additional intake of approximately 400 microg FA/d. We assessed the effectiveness of the FA flour fortification program on bread folate content and on blood folate concentration in women of childbearing age in Santiago, Chile. The prefortification folate status of 751 healthy women of reproductive age was assessed. The folate content of 100 bread samples bought at retail bakeries was measured, average wheat flour consumption was estimated and postfortification FA dietary intake was calculated. The effect of flour fortification on blood folate concentration in this group of women (n = 605) was evaluated in a follow-up study. Blood folate concentrations of the 605 women in the follow-up group increased (P < 0.0001) following fortification. Before fortification the mean serum and red blood cell folate concentrations were 9.7 +/- 4.3 and 290 +/- 102 nmol/L, respectively, compared with 37.2 +/- 9.5 and 707 +/- 179 nmol/L postfortification, respectively. The mean FA content of bread was 2020 +/- 940 micro g/kg. The median FA intake of the group evaluated postfortification was 427 microg/d (95% CI 409-445) based on an estimated intake of 219 g/d (95% CI 201-229) of wheat flour, mainly as bread. Fortification of wheat flour substantially improved folate status in a population of women of reproductive age in Chile. The effect of the FA fortification program on the occurrence of NTD is currently being assessed.

  16. Principles and status of neutron-based inspection technologies

    NASA Astrophysics Data System (ADS)

    Gozani, Tsahi

    2011-06-01

    and energetically significantly different from the background, thus making them readily distinguishable. The penetrability of neutrons as probes and signatures as well as the gamma ray signatures make neutron interrogation applicable to the inspection of large conveyances such as cars, trucks, marine containers and also smaller objects like explosive mines concealed in the ground. The application of nuclear interrogation techniques greatly depends on operational requirements. For example explosive mines and IED detection clearly require one-sided inspection, which excludes transmission based inspection (e.g., transmission radiography) and greatly limits others. The technologies developed over the last decades are now being implemented with good results. Further advances have been made over the last several years that increase the sensitivity, applicability and robustness of these systems. The principle, applications and status of neutron-based inspection techniques will be reviewed.

  17. History of medical understanding and misunderstanding of Acid base balance.

    PubMed

    Aiken, Christopher Geoffrey Alexander

    2013-09-01

    To establish how controversies in understanding acid base balance arose, the literature on acid base balance was reviewed from 1909, when Henderson described how the neutral reaction of blood is determined by carbonic and organic acids being in equilibrium with an excess of mineral bases over mineral acids. From 1914 to 1930, Van Slyke and others established our acid base principles. They recognised that carbonic acid converts into bicarbonate all non-volatile mineral bases not bound by mineral acids and determined therefore that bicarbonate represents the alkaline reserve of the body and should be a physiological constant. They showed that standard bicarbonate is a good measure of acidosis caused by increased production or decreased elimination of organic acids. However, they recognised that bicarbonate improved low plasma bicarbonate but not high urine acid excretion in diabetic ketoacidosis, and that increasing pCO2 caused chloride to shift into cells raising plasma titratable alkali. Both indicate that minerals influence pH. In 1945 Darrow showed that hyperchloraemic metabolic acidosis in preterm infants fed milk with 5.7 mmol of chloride and 2.0 mmol of sodium per 100 kcal was caused by retention of chloride in excess of sodium. Similar findings were made but not recognised in later studies of metabolic acidosis in preterm infants. Shohl in 1921 and Kildeberg in 1978 presented the theory that carbonic and organic acids are neutralised by mineral base, where mineral base is the excess of mineral cations over anions and organic acid is the difference between mineral base, bicarbonate and protein anion. The degree of metabolic acidosis measured as base excess is determined by deviation in both mineral base and organic acid from normal.

  18. Genetic variation modifies risk for neurodegeneration based on biomarker status

    PubMed Central

    Hohman, Timothy J.; Koran, Mary Ellen I.; Thornton-Wells, Tricia A.

    2014-01-01

    Background: While a great deal of work has gone into understanding the relationship between Cerebrospinal fluid (CSF) biomarkers, brain atrophy, and disease progression, less work has attempted to investigate how genetic variation modifies these relationships. The goal of this study was two-fold. First, we sought to identify high-risk vs. low-risk individuals based on their CSF tau and Aβ load and characterize these individuals with regard to brain atrophy in an AD-relevant region of interest. Next, we sought to identify genetic variants that modified the relationship between biomarker classification and neurodegeneration. Methods: Participants were categorized based on established cut-points for biomarker positivity. Mixed model regression was used to quantify longitudinal change in the left inferior lateral ventricle. Interaction analyses between single nucleotide polymorphisms (SNPs) and biomarker group status were performed using a genome wide association study (GWAS) approach. Correction for multiple comparisons was performed using the Bonferroni procedure. Results: One intergenic SNP (rs4866650) and one SNP within the SPTLC1 gene (rs7849530) modified the association between amyloid positivity and neurodegeneration. A transcript variant of WDR11-AS1 gene (rs12261764) modified the association between tau positivity and neurodegeneration. These effects were consistent across the two sub-datasets and explained approximately 3% of variance in ventricular dilation. One additional SNP (rs6887649) modified the association between amyloid positivity and baseline ventricular volume, but was not observed consistently across the sub-datasets. Conclusions: Genetic variation modifies the association between AD biomarkers and neurodegeneration. Genes that regulate the molecular response in the brain to oxidative stress may be particularly relevant to neural vulnerability to the damaging effects of amyloid-β. PMID:25140149

  19. Influence of chronic respiratory acid-base disorders on acute CO2 titration curve.

    PubMed

    Adrogué, H J; Madias, N E

    1985-04-01

    We have recently shown that background presence of chronic metabolic acid-base disorder markedly alters in vivo acute CO2 titration curve. These studies were carried out to assess the influence of chronic respiratory acid-base disorders on response to acute hypercapnia and to explore whether the chronic level of plasma pH is the factor responsible for alterations in the CO2 titration curve. We compared whole-body responses to acute hypercapnia of dogs with preexisting chronic respiratory alkalosis (n = 8) with that of normal animals (n = 4) and animals with chronic respiratory acidosis (n = 13). Chronic respiratory alkalosis and acidosis, as well as the acute CO2 titrations, were produced in unanesthetized dogs within a large environmental chamber. For comparison with our data on chronic metabolic acidosis and alkalosis, plasma bicarbonate levels, which are secondarily altered in chronic respiratory acid-base disorders, were used as an index of chronic acid-base status of the animals. Results indicate that, as with chronic metabolic acid-base disorders, a larger increment in plasma bicarbonate occurs during acute hypercapnia when steady-state plasma bicarbonate is low (respiratory alkalosis) than when it is high (respiratory acidosis). Yet, in further analogy with the metabolic studies, plasma hydrogen ion concentration is better defended at higher plasma bicarbonate levels in accordance with mathematical relationships defined by the Henderson-Hasselbalch equation. Combined results demonstrate that the influence of chronic acid-base status on whole-body response to acute hypercapnia is independent of initial plasma pH.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Acid-Base Pairs in Lewis Acidic Zeolites Promote Direct Aldol Reactions by Soft Enolization.

    PubMed

    Lewis, Jennifer D; Van de Vyver, Stijn; Román-Leshkov, Yuriy

    2015-08-17

    Hf-, Sn-, and Zr-Beta zeolites catalyze the cross-aldol condensation of aromatic aldehydes with acetone under mild reaction conditions with near quantitative yields. NMR studies with isotopically labeled molecules confirm that acid-base pairs in the Si-O-M framework ensemble promote soft enolization through α-proton abstraction. The Lewis acidic zeolites maintain activity in the presence of water and, unlike traditional base catalysts, in acidic solutions.

  1. Chip-based sequencing nucleic acids

    SciTech Connect

    Beer, Neil Reginald

    2014-08-26

    A system for fast DNA sequencing by amplification of genetic material within microreactors, denaturing, demulsifying, and then sequencing the material, while retaining it in a PCR/sequencing zone by a magnetic field. One embodiment includes sequencing nucleic acids on a microchip that includes a microchannel flow channel in the microchip. The nucleic acids are isolated and hybridized to magnetic nanoparticles or to magnetic polystyrene-coated beads. Microreactor droplets are formed in the microchannel flow channel. The microreactor droplets containing the nucleic acids and the magnetic nanoparticles are retained in a magnetic trap in the microchannel flow channel and sequenced.

  2. 45 CFR 1626.5 - Aliens eligible for assistance based on immigration status.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 4 2014-10-01 2014-10-01 false Aliens eligible for assistance based on immigration status. 1626.5 Section 1626.5 Public Welfare Regulations Relating to Public Welfare (Continued... assistance based on immigration status. Subject to all other eligibility requirements and restrictions of...

  3. Fatty acid status and behavioural symptoms of Attention Deficit Hyperactivity Disorder in adolescents: A case-control study

    PubMed Central

    Colter, Ashley L; Cutler, Caroline; Meckling, Kelly Anne

    2008-01-01

    Background Most studies of Attention-deficit hyperactivity disorder (ADHD) have focused on either young children or older adults. The current study compared 11 ADHD adolescents with 12 age-matched controls. The purpose was to examine differences in dietary intake, particularly of essential fatty acids, and determine whether this could explain the typical abnormalities in red blood cell fatty acids observed in previous studies of young children. A secondary purpose was to determine if there were relationships between circulating concentrations of essential fatty acids and specific ADHD behaviours as measured by the Conners' Parent Rating Scale (CPRS-L). Methods Eleven ADHD adolescents and twelve age-matched controls were recruited through newspaper ads, posters and a university website. ADHD diagnosis was confirmed by medical practitioners according to DSM-IV criteria. Blood, dietary intake information as well as behavioural assessments were completed. Results Results showed that ADHD adolescents consumed more energy and fat than controls but had similar anthropometry. ADHD children consumed equivalent amounts of omega-3 and omega-6 fatty acids to controls, however they had significantly lower levels of docosahexaenoic acid (DHA, 22:6n-3) and total omega-3 fatty acids, higher omega-6 fatty acids and a lower ratio of n-3:n-6 fatty acids than control subjects. In addition, low omega-3 status correlated with higher scores on several Conners' behavioural scales. Conclusion These data suggest that adolescents with ADHD continue to display abnormal essential fatty acid profiles that are often observed in younger children and distinctly different from normal controls of similar age. Further these red blood cell fatty acid differences are not explained by differences in intake. This suggests that there are metabolic differences in fatty acid handling between ADHD adolescents and normal controls. The value of omega-3 supplements to improve fatty acid profiles and possibly

  4. Assessment of acid-base balance. Stewart's approach.

    PubMed

    Fores-Novales, B; Diez-Fores, P; Aguilera-Celorrio, L J

    2016-04-01

    The study of acid-base equilibrium, its regulation and its interpretation have been a source of debate since the beginning of 20th century. Most accepted and commonly used analyses are based on pH, a notion first introduced by Sorensen in 1909, and on the Henderson-Hasselbalch equation (1916). Since then new concepts have been development in order to complete and make easier the understanding of acid-base disorders. In the early 1980's Peter Stewart brought the traditional interpretation of acid-base disturbances into question and proposed a new method. This innovative approach seems more suitable for studying acid-base abnormalities in critically ill patients. The aim of this paper is to update acid-base concepts, methods, limitations and applications.

  5. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1994-01-25

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 9 figures.

  6. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1996-07-23

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

  7. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1994-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene disphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  8. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1996-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  9. The phylogenetic status of Paxillosida (Asteroidea) based on complete mitochondrial DNA sequences.

    PubMed

    Matsubara, Mioko; Komatsu, Miéko; Araki, Takeyoshi; Asakawa, Shuichi; Yokobori, Shin-ichi; Watanabe, Kimitsuna; Wada, Hiroshi

    2005-09-01

    One of the most important issues in asteroid phylogeny is the phylogenetic status of Paxillosida. This group lacks an anus and suckers on the tube feet in adults and does not develop the brachiolaria stage in early development. Two controversial hypotheses have been proposed for the phylogenetic status of Paxillosida, i.e., Paxillosida is primitive or rather specialized in asteroids. In this study, we determined the complete mitochondrial DNA nucleotide sequences from two paxillosidans (Astropecten polyacanthus and Luidia quinaria) and one forcipulatidan (Asterias amurensis). The mitochondrial genomes of the three asteroids were identical with respect to gene order and transcription direction, and were identical to the previously reported mitochondrial genomes of Asterina pectinifera (Valvatida) and Pisaster ochraceus (Forcipulatida) in this respect. Therefore, the comparison of genome structures was uninformative for the purposes of asteroid phylogeny. However, molecular phylogenetic analyses based on the amino acid sequences and the nucleotide sequences from the five asteroids supported the monophyly of the clade that included the two paxillosidans and Asterina. This suggests that the paxillosidan characters are secondarily derived ones.

  10. Prospects for nucleic acid-based therapeutics against hepatitis C virus.

    PubMed

    Lee, Chang Ho; Kim, Ji Hyun; Lee, Seong-Wook

    2013-12-21

    In this review, we discuss recent advances in nucleic acid-based therapeutic technologies that target hepatitis C virus (HCV) infection. Because the HCV genome is present exclusively in RNA form during replication, various nucleic acid-based therapeutic approaches targeting the HCV genome, such as ribozymes, aptamers, siRNAs, and antisense oligonucleotides, have been suggested as potential tools against HCV. Nucleic acids are potentially immunogenic and typically require a delivery tool to be utilized as therapeutics. These limitations have hampered the clinical development of nucleic acid-based therapeutics. However, despite these limitations, nucleic acid-based therapeutics has clinical value due to their great specificity, easy and large-scale synthesis with chemical methods, and pharmaceutical flexibility. Moreover, nucleic acid therapeutics are expected to broaden the range of targetable molecules essential for the HCV replication cycle, and therefore they may prove to be more effective than existing therapeutics, such as interferon-α and ribavirin combination therapy. This review focuses on the current status and future prospects of ribozymes, aptamers, siRNAs, and antisense oligonucleotides as therapeutic reagents against HCV.

  11. Advances in nucleic acid-based detection methods.

    PubMed Central

    Wolcott, M J

    1992-01-01

    Laboratory techniques based on nucleic acid methods have increased in popularity over the last decade with clinical microbiologists and other laboratory scientists who are concerned with the diagnosis of infectious agents. This increase in popularity is a result primarily of advances made in nucleic acid amplification and detection techniques. Polymerase chain reaction, the original nucleic acid amplification technique, changed the way many people viewed and used nucleic acid techniques in clinical settings. After the potential of polymerase chain reaction became apparent, other methods of nucleic acid amplification and detection were developed. These alternative nucleic acid amplification methods may become serious contenders for application to routine laboratory analyses. This review presents some background information on nucleic acid analyses that might be used in clinical and anatomical laboratories and describes some recent advances in the amplification and detection of nucleic acids. PMID:1423216

  12. Mental health status of infertile couples based on treatment outcome

    PubMed Central

    Baghianimoghadam, Mohammad Hosein; Aminian, Amir Hossein; Baghianimoghadam, Behnam; Ghasemi, Nasrin; Abdoli, Ali Mohammad; Seighal Ardakani, Najmeh; Fallahzadeh, Hosein

    2013-01-01

    Background: Infertility is accompanied by numerous psychological and social problems. Infertile couples are more anxious and emotionally distressed than other fertile people. Previous studies suggested that infertility is more stressful for women than men. Objective: The purpose of this study was to determine the status of general health of infertile couples. Materials and Methods: This cross-sectional study evaluated general health of 150 infertile couples attending to Yazd Research and Clinical Center for Infertility that were selected consequently. The data were gathered by the researchers, based on face to face interview before and after three months of treatment by two questionnaires. The first questionnaire had questions on demographic information and the second one was the General Health Questionnaire-28 (GHQ-28). This questionnaire has four sub- scales areas. All data were transferred directly to SPSS 15 and analyzed. Results: The mean age of women was 28.3 and men were 32.4 years. The scores for all sub- scales of GHQ in women were more than men. There was significant difference between age and general health at physical symptoms scales (p=0.002), anxiety and sleep disorders (p=0.003). The age group 25-29 years had higher scores (more than 7) than other age groups. There was significant difference between the scale of social dysfunction and results of treatment. Conclusion: Our results, similar to the previous studies have revealed negetive social and mental effects of infertility on women is more than men, so there is need that they be educated specially. PMID:24639785

  13. What is the Ultimate Goal in Acid-Base Regulation?

    ERIC Educational Resources Information Center

    Balakrishnan, Selvakumar; Gopalakrishnan, Maya; Alagesan, Murali; Prakash, E. Sankaranarayanan

    2007-01-01

    It is common to see chapters on acid-base physiology state that the goal of acid-base regulatory mechanisms is to maintain the pH of arterial plasma and not arterial PCO [subscript 2] (Pa[subscript CO[subscript 2

  14. A Closer Look at Acid-Base Olfactory Titrations

    ERIC Educational Resources Information Center

    Neppel, Kerry; Oliver-Hoyo, Maria T.; Queen, Connie; Reed, Nicole

    2005-01-01

    Olfactory titrations using raw onions and eugenol as acid-base indicators are reported. An in-depth investigation on olfactory titrations is presented to include requirements for potential olfactory indicators and protocols for using garlic, onions, and vanillin as acid-base olfactory indicators are tested.

  15. The Roles of Acids and Bases in Enzyme Catalysis

    ERIC Educational Resources Information Center

    Weiss, Hilton M.

    2007-01-01

    Many organic reactions are catalyzed by strong acids or bases that protonate or deprotonate neutral reactants leading to reactive cations or anions that proceed to products. In enzyme reactions, only weak acids and bases are available to hydrogen bond to reactants and to transfer protons in response to developing charges. Understanding this…

  16. Total antioxidant status at high altitude in lowlanders and native highlanders: role of uric acid.

    PubMed

    Sinha, Sanchari; Singh, Som Nath; Ray, Uday Sankar

    2009-01-01

    Hypobaric hypoxia causes oxidative stress and the antioxidant system of the body plays a vital role in controlling it. Urate contributes up to two-thirds of the antioxidant capacity of human blood. The urate production is catalyzed by xanthine oxidase with a concomitant release of free radicals. This study was designed to appraise the role of urate as an antioxidant at high altitude. The study was conducted on 92 male lowlanders and 66 highlanders after ascent to high altitude at 4560 m. Blood was collected at sea level and after 4 weeks of high altitude exposure. In lowlanders, a significant increase in levels of hydroperoxide (551.4 +/- 4.2 micromol/mL vs. 582.0 +/- 3.55, p < 0.001], protein carbonyl (2.4 +/- 0.11 micromol/mL/mg protein vs. 3.03 +/- 0.11, p < 0.001), TAS (1.02 +/- 0.01 mmol/L vs. 1.19 +/- 0.02, p < 0.001), and UA (298.0 +/- 6.68 micromol/L vs. 383.0 +/- 6.55, p < 0.001) was observed at high altitude. These measurements were significantly lower in highlanders than in lowlanders at high altitude. Total antioxidant status (TAS) and uric acid (UA) showed a positive correlation in lowlanders at sea level and in highlanders at high altitude. Hydroperoxide and TAS also showed a positive correlation in both groups at high altitude. This indicates increased oxidative stress at high altitude despite an increase in antioxidant capacity in lowlanders. To conclude, a hypoxia-induced increase in UA contributes an appreciable portion of plasma total antioxidant capacity, but may not be effective in preventing oxidative stress at high altitude. PMID:19775217

  17. Connecting Acids and Bases with Encapsulation... and Chemistry with Nanotechnology

    ERIC Educational Resources Information Center

    Criswell, Brett

    2007-01-01

    The features and the development of various new acids and bases activity sets that combines chemistry with nanotechnology are being described. These sets lead to the generation of many nanotechnology-based pharmaceuticals for the treatment of various diseases.

  18. [Discovery of potential nicotinic acid receptor agonists from Chinese herbal medicines based on molecular simulation].

    PubMed

    Jiang, Lu-Di; He, Yu-Su; Zhang, Yan-Ling

    2014-12-01

    Nicotinic acid could increase high density lipoprotein and reduce serum total cholesterol, low density lipoprotein cholesterol and triglycerides in human bodies, thus is frequently applied in treating low high-density lipoprotein cholesterol and hypertriglyceridemia in clinic. However, according to the findings, nicotinic acid could also cause adverse effects, such as skin flush, beside its curative effects. In this study, bioisosterism, fragment-based search and Lipinski's Rule of Five were used to preliminarily screen out potential TCM ingredients that may have similar pharmacological effects with nicotinic acid from Traditional Chinese medicine database (TCMD). Afterwards, homology modeling and flexible docking were used to further screen out potential nicotinic acid receptor agonists. As a result, eleven candidate compounds were derived from eight commonly used traditional Chinese medicines. Specifically, all of the candidate compounds' interaction with nicotinic acid receptor was similar to nicotinic acid, and their docking scores were all higher than that of nicotinic acid, but their druggability remained to be further studied. Some of the eight source traditional Chinese medicines were used to lower lipid according to literature studies, implying that they may show effect through above means. In summary, this study provides basis and reference for extracting new nicotinic acid receptor agonists from traditional Chinese medicines and improving the medication status of hyperlipidemia.

  19. High-oleic ready-to-use therapeutic food maintains docosahexaenoic acid status in severe malnutrition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ready-to-use therapeutic food (RUTF) is the preferred treatment for uncomplicated severe acute malnutrition. It contains large amounts of linoleic acid and little a-linolenic acid, which may reduce the availability of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) to the recovering child...

  20. A Computer-Based Simulation of an Acid-Base Titration

    ERIC Educational Resources Information Center

    Boblick, John M.

    1971-01-01

    Reviews the advantages of computer simulated environments for experiments, referring in particular to acid-base titrations. Includes pre-lab instructions and a sample computer printout of a student's use of an acid-base simulation. Ten references. (PR)

  1. Nucleic acid duplexes incorporating a dissociable covalent base pair

    NASA Technical Reports Server (NTRS)

    Gao, K.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1999-01-01

    We have used molecular modeling techniques to design a dissociable covalently bonded base pair that can replace a Watson-Crick base pair in a nucleic acid with minimal distortion of the structure of the double helix. We introduced this base pair into a potential precursor of a nucleic acid double helix by chemical synthesis and have demonstrated efficient nonenzymatic template-directed ligation of the free hydroxyl groups of the base pair with appropriate short oligonucleotides. The nonenzymatic ligation reactions, which are characteristic of base paired nucleic acid structures, are abolished when the covalent base pair is reduced and becomes noncoplanar. This suggests that the covalent base pair linking the two strands in the duplex is compatible with a minimally distorted nucleic acid double-helical structure.

  2. Nucleic acid duplexes incorporating a dissociable covalent base pair.

    PubMed

    Gao, K; Orgel, L E

    1999-12-21

    We have used molecular modeling techniques to design a dissociable covalently bonded base pair that can replace a Watson-Crick base pair in a nucleic acid with minimal distortion of the structure of the double helix. We introduced this base pair into a potential precursor of a nucleic acid double helix by chemical synthesis and have demonstrated efficient nonenzymatic template-directed ligation of the free hydroxyl groups of the base pair with appropriate short oligonucleotides. The nonenzymatic ligation reactions, which are characteristic of base paired nucleic acid structures, are abolished when the covalent base pair is reduced and becomes noncoplanar. This suggests that the covalent base pair linking the two strands in the duplex is compatible with a minimally distorted nucleic acid double-helical structure. PMID:10611299

  3. Effects of dietary n-6:n-3 fatty acid ratio and vitamin E on semen quality, fatty acid composition and antioxidant status in boars.

    PubMed

    Liu, Q; Zhou, Y F; Duan, R J; Wei, H K; Jiang, S W; Peng, J

    2015-11-01

    The aim of the present study was to evaluate the effects of dietary n-6:n-3 fatty acid (FA) ratio and vitamin E on the semen quality, FA composition and antioxidant status of boars. Forty-eight Landrace boars were randomly distributed in a 3×2 factorial design with three n-6:n-3 FA ratios (14.4, 6.6 and 2.2) by the inclusion of three oil sources (soybean, fish/soybean, fish) and two vitamin E levels (200 and 400mg/kg). During the 8 weeks of treatment, semen parameters were evaluated. Serum, sperm and seminal plasma samples were taken at 0 and 8 weeks to monitor the FA composition and antioxidant status. Results showed that the 6.6 and 2.2 dietary ratios very effectively increased docosahexaenoic acid (DHA) and n-3 polyunsaturated fatty acid (PUFA) and decreased docosapentaenoic acid (DPA) and n-6:n-3 ratio in spermatozoa. The 6.6 dietary ratio contributed to a greater progressive sperm motility (P<0.05) than the 14.4 and 2.2 dietary ratio, and this ratio also enhanced the superoxide dismutase (SOD) and total antioxidant capacity (TAC) (P<0.05) in seminal plasma more significantly than the other two ratios at week 8. Compared with 200mg/kg supplementation of vitamin E, 400mg/kg supplementation of vitamin E increased the progressive sperm motility, SOD of sperm, TAC and SOD of seminal plasma and serum, and decreased sperm malondialdehyde (MDA) (P<0.05). In conclusion, the 6.6 dietary ratio and 400mg/kg vitamin E supplementation improve progressive sperm motility by modifying the sperm FA composition and antioxidant status.

  4. Organic acids and bases: Review of toxicological studies

    SciTech Connect

    Leung, H.W.; Paustenbach, D.J. )

    1990-01-01

    Organic acids and bases are among the most frequently used chemicals in the manufacturing industries. However, the toxicology of only a number of them has been fully characterized, and for fewer still have occupational exposure limits been established. This paper reviews the acute and chronic toxicity data of the organic acids and bases, and considers the mechanism by which these chemicals produce their effects. A methodology for establishing preliminary occupational exposure limits based on the physicochemical properties of these chemicals is presented. Workplace exposure limits for 20 organic acids and bases which currently have no exposure guidelines are suggested. Advice regarding appropriate medical treatment of exposure to these materials is discussed. 98 references.

  5. General base-general acid catalysis by terpenoid cyclases.

    PubMed

    Pemberton, Travis A; Christianson, David W

    2016-07-01

    Terpenoid cyclases catalyze the most complex reactions in biology, in that more than half of the substrate carbon atoms often undergo changes in bonding during the course of a multistep cyclization cascade that proceeds through multiple carbocation intermediates. Many cyclization mechanisms require stereospecific deprotonation and reprotonation steps, and most cyclization cascades are terminated by deprotonation to yield an olefin product. The first bacterial terpenoid cyclase to yield a crystal structure was pentalenene synthase from Streptomyces exfoliatus UC5319. This cyclase generates the hydrocarbon precursor of the pentalenolactone family of antibiotics. The structures of pentalenene synthase and other terpenoid cyclases reveal predominantly nonpolar active sites typically lacking amino acid side chains capable of serving general base-general acid functions. What chemical species, then, enables the Brønsted acid-base chemistry required in the catalytic mechanisms of these enzymes? The most likely candidate for such general base-general acid chemistry is the co-product inorganic pyrophosphate. Here, we briefly review biological and nonbiological systems in which phosphate and its derivatives serve general base and general acid functions in catalysis. These examples highlight the fact that the Brønsted acid-base activities of phosphate derivatives are comparable to the Brønsted acid-base activities of amino acid side chains.

  6. Acid-base properties of 2-phenethyldithiocarbamoylacetic acid, an antitumor agent

    NASA Astrophysics Data System (ADS)

    Novozhilova, N. E.; Kutina, N. N.; Petukhova, O. A.; Kharitonov, Yu. Ya.

    2013-07-01

    The acid-base properties of the 2-phenethyldithiocarbamoylacetic acid (PET) substance belonging to the class of isothiocyanates and capable of inhibiting the development of tumors on many experimental models were studied. The acidity and hydrolysis constants of the PET substance in ethanol, acetone, aqueous ethanol, and aqueous acetone solutions were determined from the data of potentiometric (pH-metric) titration of ethanol and acetone solutions of PET with aqueous solidum hydroxide at room temperature.

  7. Fortification of eggs with folic acid as a possible contribution to enhance the folic acid status of populations.

    PubMed

    Roth-Maier, Dora A; Böhmer, Barbara M

    2007-07-01

    The aim of the present study was to evaluate the enrichment of folic acid in eggs by supplementing hens' diet. Seventy-two hens (LSL) were assigned to 5 dietary groups and supplemented with 0, 0.5, 1.0, 2.0, and 4.0 mg folic acid/kg feed during an 8-week period. Eggs for folic acid analysis were collected in weeks 4 and 8 and analyzed by microbiological method using L. casei. The performance of the hens was not influenced by the supplementation. The content of folic acid in eggs increased significantly from 3.1 microg/g DM to 5.5 microg/g DM (week 4) and from 2.1 microg/g DM to 4.2 microg/g DM (week 8), respectively. One fortified egg can provide up to 76 microg folic acid. Additionally the intestinal availability of folic acid in eggs was determined in pigs as an animal model for human nutrition. Six pigs were fitted with ileorectal-anastomosis and received boiled eggs combined with a supplementary diet according to nutrient requirement. The metabolic trial ran for 12 days with a pre-period of 7 days and a collection period of 5 days. Feed and chyme were analyzed for folic acid as mentioned above. The availability of folate in eggs was determined as 68%, which means that one fortified egg provides up to 52 microg folate equivalent to 13% of the recommended daily intake.

  8. Carbon-based strong solid acid for cornstarch hydrolysis

    NASA Astrophysics Data System (ADS)

    Nata, Iryanti Fatyasari; Irawan, Chairul; Mardina, Primata; Lee, Cheng-Kang

    2015-10-01

    Highly sulfonated carbonaceous spheres with diameter of 100-500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO3H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO3H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst.

  9. Horse meat consumption affects iron status, lipid profile and fatty acid composition of red blood cells in healthy volunteers.

    PubMed

    Del Bó, Cristian; Simonetti, Paolo; Gardana, Claudio; Riso, Patrizia; Lucchini, Giorgio; Ciappellano, Salvatore

    2013-03-01

    This study investigated the effect of moderate consumption of horse meat on iron status, lipid profile and fatty acid composition of red blood cells in healthy male volunteers. Fifty-two subjects were randomly assigned to two groups of 26 subjects each: a test group consuming two portions of 175 g/week of horse meat, and a control group that abstained from eating horse meat during the 90 days trial. Before and after 90 days, blood samples were collected for analysis. Horse meat consumption significantly (p ≤ 0.05) reduced serum levels of total and low-density lipoprotein cholesterol ( - 6.2% and - 9.1%, respectively) and transferrin ( - 4.6%). Total n - 3, long chain polyunsaturated fatty acids n - 3 and docosahexeanoic acid content in erythrocytes increased (p ≤ 0.05) by about 7.8%, 8% and 11%, respectively. In conclusion, the regular consumption of horse meat may contribute to the dietary intake of n - 3 polyunsaturated fatty acids and may improve lipid profile and iron status in healthy subjects.

  10. Reactive Distillation for Esterification of Bio-based Organic Acids

    SciTech Connect

    Fields, Nathan; Miller, Dennis J.; Asthana, Navinchandra S.; Kolah, Aspi K.; Vu, Dung; Lira, Carl T.

    2008-09-23

    The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the period of October 1, 2003 to September 30, 2006, covering both reactive distillation research and development and the underlying thermodynamic and kinetic data required for successful and rigorous design of reactive distillation esterification processes. Specifically, this project has led to the development of economical, technically viable processes for ethyl lactate, triethyl citrate and diethyl succinate production, and on a larger scale has added to the overall body of knowledge on applying fermentation based organic acids as platform chemicals in the emerging biorefinery. Organic acid esters constitute an attractive class of biorenewable chemicals that are made from corn or other renewable biomass carbohydrate feedstocks and replace analogous petroleum-based compounds, thus lessening U.S. dependence on foreign petroleum and enhancing overall biorefinery viability through production of value-added chemicals in parallel with biofuels production. Further, many of these ester products are candidates for fuel (particularly biodiesel) components, and thus will serve dual roles as both industrial chemicals and fuel enhancers in the emerging bioeconomy. The technical report from MSU is organized around the ethyl esters of four important biorenewables-based acids: lactic acid, citric acid, succinic acid, and propionic acid. Literature background on esterification and reactive distillation has been provided in Section One. Work on lactic acid is covered in Sections Two through Five, citric acid esterification in Sections Six and Seven, succinic acid in Section Eight, and propionic acid in Section Nine. Section Ten covers modeling of ester and organic acid vapor pressure properties using the SPEAD (Step Potential

  11. Metabolism, gas exchange, and acid-base balance of giant salamanders.

    PubMed

    Ultsch, Gordon R

    2012-08-01

    The giant salamanders are aquatic and paedomorphic urodeles including the genera Andrias and Cryptobranchus (Cryptobranchidae), Amphiuma (Amphiumidae), Siren (Sirenidae), and Necturus (Proteidae, of which only N. maculosus is considered 'a giant'). Species in the genera Cryptobranchus and Necturus are considered aquatic salamanders well adapted for breathing water, poorly adapted for breathing air, and with limited abilities to compensate acid-base disturbances. As such, they are water-breathing animals with a somewhat fish-like respiratory and acid-base physiology, whose habitat selection is limited to waters that do not typically become hypoxic or hypercarbic (although this assertion has been questioned for N. maculosus). Siren and Amphiuma species, by contrast, are dependent upon air-breathing, have excellent lungs, inefficient (Siren) or no (Amphiuma) gills, and are obligate air-breathers with an acid-base status more similar to that of terrestrial tetrapods. As such, they can be considered to be air-breathing animals that live in water. Their response to the aquatic hypercarbia that they often encounter is to maintain intracellular pH (pH(i) ) and abandon extracellular pH regulation, a process that has been referred to as preferential pH(i) regulation. The acid-base status of some present-day tropical air-breathing fishes, and of Siren and Amphiuma, suggests that the acid-base transition from a low PCO(2) -low [] system typical of water-breathing fishes to the high PCO(2) -high [] systems of terrestrial tetrapods may have been completed before emergence onto land, and likely occurred in habitats that were typically both hypoxic and hypercarbic.

  12. Effect of acid-base alterations on hepatic lactate utilization

    PubMed Central

    Goldstein, Philip J.; Simmons, Daniel H.; Tashkin, Donald P.

    1972-01-01

    blood flow or acid-base status. PMID:5039274

  13. Polymerization of amino acids containing nucleotide bases

    NASA Technical Reports Server (NTRS)

    Ben Cheikh, Azzouz; Orgel, Leslie E.

    1990-01-01

    The nucleoamino acids 1-(3'-amino,3'-carboxypropyl)uracil (3) and 9-(3'-amino,3'-carboxypropyl)adenine (4) have been prepared as (L)-en-antiomers and as racemic mixtures. When 3 or 4 is suspended in water and treated with N,N'-carbon-yldiimidazole, peptides are formed in good yield. The products formed from the (L)-enantiomers are hydrolyzed to the monomeric amino acids by pronase. Attempts to improve the efficiency of these oligomerizations by including a polyuridylate template in the reaction mixture were not successful. Similarly, oligomers derived from the (L)-enantiomer of 3 did not act as templates to facilitate the oligomerization of 4.

  14. Perfluoroalkyl acids in the Canadian environment: multi-media assessment of current status and trends.

    PubMed

    Gewurtz, Sarah B; Backus, Sean M; De Silva, Amila O; Ahrens, Lutz; Armellin, Alain; Evans, Marlene; Fraser, Susan; Gledhill, Melissa; Guerra, Paula; Harner, Tom; Helm, Paul A; Hung, Hayley; Khera, Nav; Kim, Min Gu; King, Martha; Lee, Sum Chi; Letcher, Robert J; Martin, Pamela; Marvin, Chris; McGoldrick, Daryl J; Myers, Anne L; Pelletier, Magella; Pomeroy, Joe; Reiner, Eric J; Rondeau, Myriam; Sauve, Marie-Claude; Sekela, Mark; Shoeib, Mahiba; Smith, Daniel W; Smyth, Shirley Anne; Struger, John; Spry, Doug; Syrgiannis, Jim; Waltho, Jasmine

    2013-09-01

    In Canada, perfluoroalkyl acids (PFAAs) have been the focus of several monitoring programs and research and surveillance studies. Here, we integrate recent data and perform a multi-media assessment to examine the current status and ongoing trends of PFAAs in Canada. Concentrations of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and other long-chain perfluorocarboxylates (PFCAs) in air, water, sediment, fish, and birds across Canada are generally related to urbanization, with elevated concentrations observed around cities, especially in southern Ontario. PFOS levels in water, fish tissue, and bird eggs were below their respective Draft Federal Environmental Quality Guidelines, suggesting there is low potential for adverse effects to the environment/organisms examined. However, PFOS in fish and bird eggs tended to exceed guidelines for the protection of mammalian and avian consumers, suggesting a potential risk to their wildlife predators, although wildlife population health assessments are needed to determine whether negative impacts are actually occurring. Long-term temporal trends of PFOS in suspended sediment, sediment cores, Lake Trout (Salvelinus namaycush), and Herring Gull (Larus argentatus) eggs collected from Lake Ontario increased consistently from the start of data collection until the 1990s. However, after this time, the trends varied by media, with concentrations stabilizing in Lake Trout and Herring Gull eggs, and decreasing and increasing in suspended sediment and the sediment cores, respectively. For PFCAs, concentrations in suspended sediment, sediment cores, and Herring Gulls generally increased from the start of data collection until present and concentrations in Lake Trout increased until the late 1990s and subsequently stabilized. A multimedia comparison of PFAA profiles provided evidence that unexpected patterns in biota of some of the lakes were due to unique source patterns rather than internal lake processes. High

  15. Acid deposition in Maryland: the status of knowledge in 1987. Annual report

    SciTech Connect

    Not Available

    1988-01-01

    The Power Plant Research Program coordinates Maryland's acid deposition research and reports research results annually. The report evaluates several major topic areas including transport and chemistry of acid deposition its potential impacts on the State's streams and fish, possible impacts on terrestrial resources such as crops and forests and on materials, the ability of energy-conservation programs to reduce emissions of acid-forming pollutants, and mitigation techniques for neutralizing acid waters.

  16. Carbon-based strong solid acid for cornstarch hydrolysis

    SciTech Connect

    Nata, Iryanti Fatyasari; Irawan, Chairul; Mardina, Primata; Lee, Cheng-Kang

    2015-10-15

    Highly sulfonated carbonaceous spheres with diameter of 100–500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO{sub 3}H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO{sub 3}H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst. - Highlights: • Carbon solid acid was successfully prepared by one-step hydrothermal carbonization. • The acrylic acid as monomer was effectively reduce the diameter size of particle. • The solid acid catalyst show good catalytic performance of starch hydrolysis. • The solid acid catalyst is not significantly deteriorated after repeated use.

  17. Effects of eicosapentaenoic acid (EPA) treatment on insulin sensitivity in an animal model of diabetes: improvement of the inflammatory status.

    PubMed

    Figueras, Maite; Olivan, Mireia; Busquets, Sílvia; López-Soriano, Francisco J; Argilés, Josep M

    2011-02-01

    In addition to decreased insulin sensitivity, diabetes is a pathological condition associated with increased inflammation. The ω-3 fatty acids have been proposed as anti-inflammatory agents. Thus, the major goal of this study was to analyze the effects of fatty acid supplementation on both insulin sensitivity and inflammatory status in an animal model of type 2 diabetes. Diabetic rats (Goto-Kakizaki model) were treated with eicosapentaenoic acid (EPA) or linoleic acid at 0.5 g/kg body weigh (bw) dose. In vivo incorporation of (14)C-triolein into adipose tissue was improved by the ω-3 administration. In vitro incubations of adipose tissue slices from EPA-treated rats showed an increase in (14)C-palmitate incorporation into the lipid fraction. These observations were linked with a decreased rate of fatty acid oxidation. EPA treatment resulted in a decreased fatty acid oxidation in incubated strips from extensor digitorum longus (EDL) muscles. The changes in lipid utilization were associated with a decrease in insulin plasma concentration, suggesting an improvement in insulin sensitivity. These changes in lipid metabolism were associated with an activation of AMP-activated protein kinase (AMPK) in white adipose tissue. In addition, EPA treatment resulted in a decreased content of peroxisome proliferator-activated receptor-α (PPARα) and PPARδ and in increased GLUT4 expression in skeletal muscle. Moreover, EPA increased 2-deoxy-D-[(14)C]glucose (2-DOG) uptake in C2C12 myotubes, suggesting an improvement in glucose metabolism. Concerning the inflammatory status, EPA treatment resulted in a decreased gene expression for both tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) both in skeletal muscle and adipose tissue. The data suggest that EPA treatment to diabetic rats clearly improves lipid metabolism although the evidences on insulin sensitization are less clear. PMID:20885391

  18. Effects of eicosapentaenoic acid (EPA) treatment on insulin sensitivity in an animal model of diabetes: improvement of the inflammatory status.

    PubMed

    Figueras, Maite; Olivan, Mireia; Busquets, Sílvia; López-Soriano, Francisco J; Argilés, Josep M

    2011-02-01

    In addition to decreased insulin sensitivity, diabetes is a pathological condition associated with increased inflammation. The ω-3 fatty acids have been proposed as anti-inflammatory agents. Thus, the major goal of this study was to analyze the effects of fatty acid supplementation on both insulin sensitivity and inflammatory status in an animal model of type 2 diabetes. Diabetic rats (Goto-Kakizaki model) were treated with eicosapentaenoic acid (EPA) or linoleic acid at 0.5 g/kg body weigh (bw) dose. In vivo incorporation of (14)C-triolein into adipose tissue was improved by the ω-3 administration. In vitro incubations of adipose tissue slices from EPA-treated rats showed an increase in (14)C-palmitate incorporation into the lipid fraction. These observations were linked with a decreased rate of fatty acid oxidation. EPA treatment resulted in a decreased fatty acid oxidation in incubated strips from extensor digitorum longus (EDL) muscles. The changes in lipid utilization were associated with a decrease in insulin plasma concentration, suggesting an improvement in insulin sensitivity. These changes in lipid metabolism were associated with an activation of AMP-activated protein kinase (AMPK) in white adipose tissue. In addition, EPA treatment resulted in a decreased content of peroxisome proliferator-activated receptor-α (PPARα) and PPARδ and in increased GLUT4 expression in skeletal muscle. Moreover, EPA increased 2-deoxy-D-[(14)C]glucose (2-DOG) uptake in C2C12 myotubes, suggesting an improvement in glucose metabolism. Concerning the inflammatory status, EPA treatment resulted in a decreased gene expression for both tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) both in skeletal muscle and adipose tissue. The data suggest that EPA treatment to diabetic rats clearly improves lipid metabolism although the evidences on insulin sensitization are less clear.

  19. The acid-base titration of montmorillonite

    NASA Astrophysics Data System (ADS)

    Bourg, I. C.; Sposito, G.; Bourg, A. C.

    2003-12-01

    Proton binding to clay minerals plays an important role in the chemical reactivity of soils (e.g., acidification, retention of nutrients or pollutants). If should also affect the performance of clay barriers for waste disposal. The surface acidity of clay minerals is commonly modelled empirically by assuming generic amphoteric surface sites (>SOH) on a flat surface, with fitted site densities and acidity constant. Current advances in experimental methods (notably spectroscopy) are rapidly improving our understanding of the structure and reactivity of the surface of clay minerals (arrangement of the particles, nature of the reactive surface sites, adsorption mechanisms). These developments are motivated by the difficulty of modelling the surface chemistry of mineral surfaces at the macro-scale (e.g., adsorption or titration) without a detailed (molecular-scale) picture of the mechanisms, and should be progressively incorporated into surface complexation models. In this view, we have combined recent estimates of montmorillonite surface properties (surface site density and structure, edge surface area, surface electrostatic potential) with surface site acidities obtained from the titration of alpha-Al2O3 and SiO2, and a novel method of accounting for the unknown initial net proton surface charge of the solid. The model predictions were compared to experimental titrations of SWy-1 montmorillonite and purified MX-80 bentonite in 0.1-0.5 mol/L NaClO4 and 0.005-0.5 mol/L NaNO3 background electrolytes, respectively. Most of the experimental data were appropriately described by the model after we adjusted a single parameter (silanol sites on the surface of montmorillonite were made to be slightly more acidic than those of silica). At low ionic strength and acidic pH the model underestimated the buffering capacity of the montmorillonite, perhaps due to clay swelling or to the interlayer adsorption of dissolved aluminum. The agreement between our model and the experimental

  20. Differential titration of bases in glacial acetic acid.

    PubMed

    Castellano, T; Medwick, T; Shinkai, J H; Bailey, L

    1981-01-01

    A study of bases in acetic acid and their differential titration was carried out. The overall basicity constants for 20 bases were measured in acetic acid, and the differential titration of five binary mixtures of variable delta pKb values in acetic acid was followed using a glass electrode-modified calomel electrode system. Agreement with literature values was good. A leveling diagram was constructed that indicated that bases stronger than aqueous pKb 10 are leveled to an acetous pKb 5.69, whereas weaker bases are not leveled but instead exhibit their own intrinsic basicity, with the acetous pKb to aqueous pKb values being linearly related (slope 1.18, correlation coefficient 0.962). A minimum acetous delta pKb of four units is required for the satisfactory differential titration of two bases in acetic acid.

  1. Potentiometric Acid-Base Titrations with Activated Graphite Electrodes

    NASA Astrophysics Data System (ADS)

    Riyazuddin, P.; Devika, D.

    1997-10-01

    Dry cell graphite (DCG) electrodes activated with potassium permanganate are employed as potentiometric indicator electrodes for acid-base titrations. Special attention is given to an indicator probe comprising activated DCG-non-activiated DCG electrode couple. This combination also proves suitable for the titration of strong or weak acids.

  2. Nucleic acid based fluorescent sensor for mercury detection

    DOEpatents

    Lu, Yi; Liu, Juewen

    2013-02-05

    A nucleic acid enzyme comprises an oligonucleotide containing thymine bases. The nucleic acid enzyme is dependent on both Hg.sup.2+and a second ion as cofactors, to produce a product from a substrate. The substrate comprises a ribonucleotide, a deoxyribonucleotide, or both.

  3. Modulation of hepatic phase II phenol sulfotransferase and antioxidant status by phenolic acids in rats.

    PubMed

    Yeh, Chi-Tai; Yen, Gow-Chin

    2006-08-01

    Phenolic acids have significant biological and pharmacological properties and some have demonstrated remarkable ability to alter sulfate conjugation. However, the modulatory effects of phenolic acids on phenol sulfotransferases (PSTs) in vivo have not been described. The present investigation evaluates the role of phenolic acid on the expression of PSTs in male Sprague-Dawley rat liver. According to the results, gentisic acid, gallic acid and p-coumaric acid in a dosage of 100 mg/kg of body weight for 14 consecutive days significantly increased P-form PST (PST-P) activity as compared with that of the control rats (P<.05), whereas the activity of M-form PST (PST-M) in rats that received gallic acid and p-coumaric acid were also significantly (P<.05) higher than in the control rats. Reverse transcriptase-polymerase chain reaction results indicated that the changes in both PST-P and PST-M mRNA levels by phenolic acids were similar to those noted in the enzyme activity levels. The plasma obtained from phenolic acid-administered rats had significantly (P<.05) increased oxygen radical absorbance capacity (ORAC(ROO*) values than that from control rats. In a bioavailability study, following oral administration of gallic acid and p-coumaric acid, the phenolic acids were detected in the plasma, and the Cmax values after 2.0-h administration were 665+/-23 and 550+/-33 nmol/L, respectively. There was a significant correlation between the activity of both forms of PSTs and the antioxidant capacity of ORAC(ROO*) value by phenolic acids (r=.74, P<.05 and r=.77, P<.05). These data suggest that phenolic acids might alter sulfate conjugation and antioxidant capacity in living systems. PMID:16443358

  4. Development status of a sealed bipolar lead/acid battery for high-power battery applications

    NASA Astrophysics Data System (ADS)

    Arias, J. L.; Rowlette, J. J.; Drake, E. D.

    A sealed bipolar lead/acid (SBLA) battery is being developed by Arias Research Associates (ARA) which will offer a number of important advantages in applications requiring high power densities. These applications include electric vehicles (EVs) and hybrid electric vehicles, uninterruptable power supplies (UPS), electrically-heated catalysts (EHCs) for automobiles, utility-power peak-shaving, and others. The advantages of the SBLA over other types of batteries will by significantly higher power density, together with good energy density, high cycle life, high voltage density, low production cost and zero maintenance. In addition, the lead/acid battery represents a technology which is familiar and accepted by Society, is recyclable within the existing infrastructure, and does not raise the safety concerns of many other new batteries (e.g., fire, explosion and toxic gases). This paper briefly reviews the basic design concepts and issues of the SBLA battery technology, various quasi-bipolar approaches and the results of ARA's development work during the past four years. Performance data are given based on both in-house and independent testing of ARA laboratory test batteries. In addition, performance projections and other characteristics are given for three ARA SBLA battery designs, which are compared with other batteries in three example applications: UPS, EHCs, and EVs. The most notable advantages of the SBLA battery are substantial reductions in product size and weight for the UPS, smaller packaging and longer life for the EHC, and higher vehicle performance and lower cost for the EV, compared to both existing and advanced EV batteries.

  5. Soil acidity status in the vicinity of the Severonikel copper-nickel industrial complex, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Kashulina, G. M.; Kubrak, A. N.; Korobeinikova, N. M.

    2015-04-01

    The physicochemical properties of soils exposed to emissions from the Severonikel industrial complex (one of the largest sources of SO2 and heavy metals in northern Europe) for 70 years were studied. The results showed that even after the long-term impact of heavy SO2 emissions, the , the content of exchangeable bases, and the base saturation remained at the medium and high levels inherent to undisturbed soils of the region studied. An exclusion was the illuvial horizon of the podzols, where a relative reduction of the (at the level of low values of the natural variation) was revealed. At the same time, the hydrolytic acidity and cation exchange capacity in most samples of podzols, peat eutrophic, and mountain soils in the zone exposed to emissions (local zone) were also reduced. This fact is explained by indirect effects of the emissions: the gradual decrease in the organic matter content in the soils due to the destruction of the vegetation, the absence of fresh plant falloff, the development of erosion, and the disturbance of the hydrological regime of the soils and landscapes.

  6. Acid-base titration curves for acids with very small ratios of successive dissociation constants.

    PubMed

    Campbell, B H; Meites, L

    1974-02-01

    The shapes of the potentiometric acid-base titration curves obtained in the neutralizations of polyfunctional acids or bases for which each successive dissociation constant is smaller than the following one are examined. In the region 0 < < 1 (where is the fraction of the equivalent volume of reagent that has been added) the slope of the titration curve decreases as the number j of acidic or basic sites increases. The difference between the pH-values at = 0.75 and = 0.25 has (1 j)log 9 as the lower limit of its maximum value.

  7. Laser Acupuncture Improves Behavioral Disorders and Brain Oxidative Stress Status in the Valproic Acid Rat Model of Autism.

    PubMed

    Khongrum, Jurairat; Wattanathorn, Jintanaporn

    2015-08-01

    The therapeutic strategy against autism, a severe neurological development disorder, is one of the challenges of this decade. Recent findings show that oxidative stress plays a crucial role on the pathophysiology of autism, and laser acupuncture at Shenmen (HT7) can improve oxidative status in many neurological disorders. Therefore, we aimed to assess the effect of laser acupuncture at HT7 on behavior disorders and oxidative stress status in the cortex, striatum, and hippocampus of the valproic acid rat model of autism. Laser acupuncture was performed once daily during postnatal day (PND) 14-PND 40. Behavioral tests including rotarod, open-field, learning and memory, and social behavior tests were performed during PND 14-PND 40. At the end of study, brain oxidative status including malondialdehyde levels and the activities of superoxide dismutase, catalase, and glutathione peroxidase were determined in the cortex, striatum, and hippocampus. Laser acupuncture at HT7 significantly improved autistic-like behaviors. Decreased malondialdehyde levels were observed in all areas mentioned above, however, increased glutathione peroxidase activity was observed only in the striatum and hippocampus. No changes in superoxide dismutase and catalase activities were observed in any investigated area of the brain. Therefore, our study suggests that laser acupuncture at HT7 partly mitigates autistic-like symptoms via improved oxidative status.

  8. Renal acidification responses to respiratory acid-base disorders.

    PubMed

    Madias, Nicolaos E

    2010-01-01

    Respiratory acid-base disorders are those abnormalities in acid-base equilibrium that are expressed as primary changes in the arterial carbon dioxide tension (PaCO2). An increase in PaCO2 (hypercapnia) acidifies body fluids and initiates the acid-base disturbance known as respiratory acidosis. By contrast, a decrease in PaCO2 (hypocapnia) alkalinizes body fluids and initiates the acid-base disturbance known as respiratory alkalosis. The impact on systemic acidity of these primary changes in PaCO2 is ameliorated by secondary, directional changes in plasma [HCO3¯] that occur in 2 stages. Acutely, hypercapnia or hypocapnia yields relatively small changes in plasma [HCO3¯] that originate virtually exclusively from titration of the body's nonbicarbonate buffers. During sustained hypercapnia or hypocapnia, much larger changes in plasma [HCO3¯] occur that reflect adjustments in renal acidification mechanisms. Consequently, the deviation of systemic acidity from normal is smaller in the chronic forms of these disorders. Here we provide an overview of the renal acidification responses to respiratory acid-base disorders. We also identify gaps in knowledge that require further research.

  9. An Olfactory Indicator for Acid-Base Titrations.

    ERIC Educational Resources Information Center

    Flair, Mark N.; Setzer, William N.

    1990-01-01

    The use of an olfactory acid-base indicator in titrations for visually impaired students is discussed. Potential olfactory indicators include eugenol, thymol, vanillin, and thiophenol. Titrations performed with each indicator with eugenol proved to be successful. (KR)

  10. Biologist's Toolbox. Acid-base Balance: An Educational Computer Game.

    ERIC Educational Resources Information Center

    Boyle, Joseph, III; Robinson, Gloria

    1987-01-01

    Describes a microcomputer program that can be used in teaching the basic physiological aspects of acid-base (AB) balance. Explains how its game format and graphic approach can be applied in diagnostic and therapeutic exercises. (ML)

  11. Towards lactic acid bacteria-based biorefineries.

    PubMed

    Mazzoli, Roberto; Bosco, Francesca; Mizrahi, Itzhak; Bayer, Edward A; Pessione, Enrica

    2014-11-15

    Lactic acid bacteria (LAB) have long been used in industrial applications mainly as starters for food fermentation or as biocontrol agents or as probiotics. However, LAB possess several characteristics that render them among the most promising candidates for use in future biorefineries in converting plant-derived biomass-either from dedicated crops or from municipal/industrial solid wastes-into biofuels and high value-added products. Lactic acid, their main fermentation product, is an attractive building block extensively used by the chemical industry, owing to the potential for production of polylactides as biodegradable and biocompatible plastic alternative to polymers derived from petrochemicals. LA is but one of many high-value compounds which can be produced by LAB fermentation, which also include biofuels such as ethanol and butanol, biodegradable plastic polymers, exopolysaccharides, antimicrobial agents, health-promoting substances and nutraceuticals. Furthermore, several LAB strains have ascertained probiotic properties, and their biomass can be considered a high-value product. The present contribution aims to provide an extensive overview of the main industrial applications of LAB and future perspectives concerning their utilization in biorefineries. Strategies will be described in detail for developing LAB strains with broader substrate metabolic capacity for fermentation of cheaper biomass.

  12. Towards lactic acid bacteria-based biorefineries.

    PubMed

    Mazzoli, Roberto; Bosco, Francesca; Mizrahi, Itzhak; Bayer, Edward A; Pessione, Enrica

    2014-11-15

    Lactic acid bacteria (LAB) have long been used in industrial applications mainly as starters for food fermentation or as biocontrol agents or as probiotics. However, LAB possess several characteristics that render them among the most promising candidates for use in future biorefineries in converting plant-derived biomass-either from dedicated crops or from municipal/industrial solid wastes-into biofuels and high value-added products. Lactic acid, their main fermentation product, is an attractive building block extensively used by the chemical industry, owing to the potential for production of polylactides as biodegradable and biocompatible plastic alternative to polymers derived from petrochemicals. LA is but one of many high-value compounds which can be produced by LAB fermentation, which also include biofuels such as ethanol and butanol, biodegradable plastic polymers, exopolysaccharides, antimicrobial agents, health-promoting substances and nutraceuticals. Furthermore, several LAB strains have ascertained probiotic properties, and their biomass can be considered a high-value product. The present contribution aims to provide an extensive overview of the main industrial applications of LAB and future perspectives concerning their utilization in biorefineries. Strategies will be described in detail for developing LAB strains with broader substrate metabolic capacity for fermentation of cheaper biomass. PMID:25087936

  13. Trace element status and fatty acids metabolism during healthy ageing: an example of a population from the Tunisian eastern coast.

    PubMed

    Sfar, Sonia; El Heni, Jihen; Laporte, François; Braham, Hamadi; Jawed, Abdelhafidh; Amor, Salah; Sfar, Mohamed Tahar; Kerkeni, Abdelhamid

    2012-03-01

    Micronutrients as well as essential fatty acids are indispensable for the correct functioning of the organism. The risk of disturbance in the associated nutrition and metabolism is expected to increase during ageing. In addition, it seems that trace elements are involved in the fatty acids metabolism. The aim of the present study was then to assess age-related changes in trace elements status and in plasma essential fatty acids composition with an emphasis on the desaturase activity estimation. Two hundred healthy Tunisian subjects (30-85 years old) were recruited and separated into two subgroups: elderly (65-85 years old) and middle-aged (30-60 years old). The findings revealed that plasma zinc and calcium concentrations significantly decreased according to age. The prevalence of zinc deficiency was therefore shown to increase in old age (over 60% of elderly subjects were deficient or at risk of deficiency). No age-related changes were obtained for copper or magnesium status. The Δ6 desaturase, involved in the EFAs conversion, was shown to decrease according to age and to be associated with the plasma zinc level. Since elderly subjects were at risk of nutritional imbalance, it would be interesting to set optimal dietary proportion. This will help to prevent age-associated alterations and diseases for a better and healthy ageing. PMID:22222317

  14. Docosahexaenoic acid status at 9 months is inversely associated with communicative skills in 3-year-old girls.

    PubMed

    Engel, Sara; Tronhjem, Kathrine Marie Hagerup; Hellgren, Lars I; Michaelsen, Kim F; Lauritzen, Lotte

    2013-10-01

    The objective of the present observational study was to investigate if the docosahexaenoic acid (DHA) status assessed in infant erythrocytes (RBC) at 9 months was associated with the age when the infants reach developmental milestones and their psychomotor function at 3 years of age. Three hundred eleven healthy Danish children were followed from 9 months to 3 years of age (the SKOT cohort). RBC fatty acid composition was analysed by gas chromatography in 272 of the children. Milestone age was collected by questionnaires at 9 and 18 months and psychomotor development at 3 years of age was assessed by the parents using third edition of the Ages and Stages Questionnaire (ASQ-3). RBC DHA levels ranged from 2.2% to 12.6% of the RBC fatty acids. The age of reaching milestones correlated with psychomotor development, particularly with gross motor function at 3 years. An association between milestones and later personal and social skills was also observed, but only for girls. In girls, RBC-DHA was found to be inversely correlated with communication at 3 years of age (odds ratio = 0.69, 95% confidence interval: 0.56-0.86, P = 0.001), but no other associations with psychomotor development or milestones were found. The results from study indicate that DHA status at 9 months may not have a pronounced beneficial effect on psychomotor development in early childhood and that communicative skills at 3 years of age may even be inversely associated with early RBC-DHA levels in girls.

  15. Chronic ethanol exposure and folic acid supplementation: fetal growth and folate status in the maternal and fetal guinea pig.

    PubMed

    Hewitt, Amy J; Knuff, Amber L; Jefkins, Matthew J; Collier, Christine P; Reynolds, James N; Brien, James F

    2011-05-01

    Chronic ethanol exposure (CEE) can produce developmental abnormalities in the CNS of the embryo and developing fetus. Folic acid (FA) is an important nutrient during pregnancy and low folate status exacerbates ethanol-induced teratogenicity. This study tested the hypotheses that (1) CEE depletes folate stores in the mother and fetus; and (2) maternal FA supplementation maintains folate stores. CEE decreased fetal body, brain, hippocampus weights, and brain to body weight ratio but not hippocampus to body weight ratio. These effects of CEE were not mitigated by maternal FA administration. The FA regimen prevented the CEE-induced decrease of term fetal liver folate. However, it did not affect maternal liver folate or fetal RBC folate at term, and did not mitigate the nutritional deficit-induced decrease of term fetal hippocampus folate. This study suggests that maternal FA supplementation may have differential effects on folate status in the mother and the fetus. PMID:21315145

  16. Chronic ethanol exposure and folic acid supplementation: fetal growth and folate status in the maternal and fetal guinea pig.

    PubMed

    Hewitt, Amy J; Knuff, Amber L; Jefkins, Matthew J; Collier, Christine P; Reynolds, James N; Brien, James F

    2011-05-01

    Chronic ethanol exposure (CEE) can produce developmental abnormalities in the CNS of the embryo and developing fetus. Folic acid (FA) is an important nutrient during pregnancy and low folate status exacerbates ethanol-induced teratogenicity. This study tested the hypotheses that (1) CEE depletes folate stores in the mother and fetus; and (2) maternal FA supplementation maintains folate stores. CEE decreased fetal body, brain, hippocampus weights, and brain to body weight ratio but not hippocampus to body weight ratio. These effects of CEE were not mitigated by maternal FA administration. The FA regimen prevented the CEE-induced decrease of term fetal liver folate. However, it did not affect maternal liver folate or fetal RBC folate at term, and did not mitigate the nutritional deficit-induced decrease of term fetal hippocampus folate. This study suggests that maternal FA supplementation may have differential effects on folate status in the mother and the fetus.

  17. Amino Acid Homeostasis Modulates Salicylic Acid–Associated Redox Status and Defense Responses in Arabidopsis[C][W][OA

    PubMed Central

    Liu, Guosheng; Ji, Yuanyuan; Bhuiyan, Nazmul H.; Pilot, Guillaume; Selvaraj, Gopalan; Zou, Jitao; Wei, Yangdou

    2010-01-01

    The tight association between nitrogen status and pathogenesis has been broadly documented in plant–pathogen interactions. However, the interface between primary metabolism and disease responses remains largely unclear. Here, we show that knockout of a single amino acid transporter, LYSINE HISTIDINE TRANSPORTER1 (LHT1), is sufficient for Arabidopsis thaliana plants to confer a broad spectrum of disease resistance in a salicylic acid–dependent manner. We found that redox fine-tuning in photosynthetic cells was causally linked to the lht1 mutant-associated phenotypes. Furthermore, the enhanced resistance in lht1 could be attributed to a specific deficiency of its main physiological substrate, Gln, and not to a general nitrogen deficiency. Thus, by enabling nitrogen metabolism to moderate the cellular redox status, a plant primary metabolite, Gln, plays a crucial role in plant disease resistance. PMID:21097712

  18. Synthesis and antimicrobial activities of new higher amino acid Schiff base derivatives of 6-aminopenicillanic acid and 7-aminocephalosporanic acid

    NASA Astrophysics Data System (ADS)

    Özdemir (nee Güngör), Özlem; Gürkan, Perihan; Özçelik, Berrin; Oyardı, Özlem

    2016-02-01

    Novel β-lactam derivatives (1c-3c) (1d-3d) were produced by using 6-aminopenicillanic acid (6-APA), 7-aminocephalosporanic acid (7-ACA) and the higher amino acid Schiff bases. The synthesized compounds were characterized by elemental analysis, IR, 1H/13C NMR and UV-vis spectra. Antibacterial activities of all the higher amino acid Schiff bases (1a-3a) (1b-3b) and β-lactam derivatives were screened against three gram negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii RSKK 02026), three gram positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 07005, Bacillus subtilis ATCC 6633) and their drug-resistant isolates by using broth microdilution method. Two fungi (Candida albicans and Candida krusei) were used for antifungal activity.

  19. Influence of formulas with borage oil or borage oil plus fish oil on the arachidonic acid status in premature infants.

    PubMed

    Demmelmair, H; Feldl, F; Horváth, I; Niederland, T; Ruszinkó, V; Raederstorff, D; De Min, C; Muggli, R; Koletzko, B

    2001-06-01

    Several studies have reported that feeding gamma-linolenic acid (GLA) has resulted in no increase in arachidonic acid (AA) in newborns. This result was ascribed to the eicosapentaenoic acid (EPA)-rich fish oil used in these formulas. Docosahexaenoic acid (DHA) sources with only minor amounts of EPA are now available, thus the addition of GLA to infant formulas might be considered an alternative to AA supplementation. Sixty-six premature infants were randomized to feeding one of four formulas [ST: no GLA, no long-chain polyunsaturated fatty acids; BO: 0.6% GLA (borage oil); BO + FOLOW: 0.6% GLA, 0.3% DHA, 0.06% EPA; BO + FOHIGH: 0.6% GLA, 0.3% DHA, 0.2% EPA] or human milk (HM, nonrandomized) for 4 wk. Anthropometric measures and blood samples were obtained at study entry and after 14 and 28 d. There were no significant differences between groups in anthropometric measures, tocopherol, and retinol status at any of the studied time points. The AA content of plasma phospholipids was similar between groups at study start and decreased significantly until day 28 in all formulafed groups, but not in the breast-fed infants [ST: 6.6 +/- 0.2%, BO: 6.9 +/- 0.3%, BO + FOLOW: 6.9 +/- 0.4%, BO + FOHIGH: 6.7 +/- 0.2%, HM: 8.6 +/- 0.5%, where values are reported as mean +/- standard error; all formulas significantly different (P< 0.05) from HM]. There was no significant influence of GLA or fish oil addition to the diet. GLA had only a very limited effect on AA status which was too small to obtain satisfactory concentrations (concentrations similar to breast-fed babies) under the circumstances tested. The effect of GLA on AA is independent of the EPA and DHA content in the diet within the dose ranges studied. PMID:11485158

  20. Influence of formulas with borage oil or borage oil plus fish oil on the arachidonic acid status in premature infants.

    PubMed

    Demmelmair, H; Feldl, F; Horváth, I; Niederland, T; Ruszinkó, V; Raederstorff, D; De Min, C; Muggli, R; Koletzko, B

    2001-06-01

    Several studies have reported that feeding gamma-linolenic acid (GLA) has resulted in no increase in arachidonic acid (AA) in newborns. This result was ascribed to the eicosapentaenoic acid (EPA)-rich fish oil used in these formulas. Docosahexaenoic acid (DHA) sources with only minor amounts of EPA are now available, thus the addition of GLA to infant formulas might be considered an alternative to AA supplementation. Sixty-six premature infants were randomized to feeding one of four formulas [ST: no GLA, no long-chain polyunsaturated fatty acids; BO: 0.6% GLA (borage oil); BO + FOLOW: 0.6% GLA, 0.3% DHA, 0.06% EPA; BO + FOHIGH: 0.6% GLA, 0.3% DHA, 0.2% EPA] or human milk (HM, nonrandomized) for 4 wk. Anthropometric measures and blood samples were obtained at study entry and after 14 and 28 d. There were no significant differences between groups in anthropometric measures, tocopherol, and retinol status at any of the studied time points. The AA content of plasma phospholipids was similar between groups at study start and decreased significantly until day 28 in all formulafed groups, but not in the breast-fed infants [ST: 6.6 +/- 0.2%, BO: 6.9 +/- 0.3%, BO + FOLOW: 6.9 +/- 0.4%, BO + FOHIGH: 6.7 +/- 0.2%, HM: 8.6 +/- 0.5%, where values are reported as mean +/- standard error; all formulas significantly different (P< 0.05) from HM]. There was no significant influence of GLA or fish oil addition to the diet. GLA had only a very limited effect on AA status which was too small to obtain satisfactory concentrations (concentrations similar to breast-fed babies) under the circumstances tested. The effect of GLA on AA is independent of the EPA and DHA content in the diet within the dose ranges studied.

  1. Acid-base homeostasis in the human system

    NASA Technical Reports Server (NTRS)

    White, R. J.

    1974-01-01

    Acid-base regulation is a cooperative phenomena in vivo with body fluids, extracellular and intracellular buffers, lungs, and kidneys all playing important roles. The present account is much too brief to be considered a review of present knowledge of these regulatory systems, and should be viewed, instead, as a guide to the elements necessary to construct a simple model of the mutual interactions of the acid-base regulatory systems of the body.

  2. Effects of rice bran on performance, egg quality, oxidative status, yolk fatty acid composition, and fatty acid metabolism-related gene expression in laying ducks.

    PubMed

    Ruan, D; Lin, Y C; Chen, W; Wang, S; Xia, W G; Fouad, A M; Zheng, C T

    2015-12-01

    The study was designed to evaluate the effects of different dietary levels of rice bran (RB) in laying duck diets on performance, egg quality, oxidation status, egg yolk fatty acid composition, and hepatic expression of fatty acid metabolism-related genes. Longyan females (1080) with similar BW at 19 wk of age were randomly assigned to 6 dietary treatments, each consisting of 6 replicates of 30 birds. The basal diet (I) was a typical corn-soybean ration while the experimental diets (II to VI) substituted RB for corn and wheat bran and a small reduction of soybean meal. The level of substitution in diets (II to VI) was 6%, 12%, 18%, 24%, and 30%, respectively. The experiment lasted for 12 wks. Average egg weight and daily egg mass decreased linearly as the level of RB inclusion increased (P<0.001) and feed conversion ratio linearly increased (P<0.001). The proportions of C14:0 and C18:0 and total saturated fatty acids (SFA) in egg yolk linearly decreased with increasing RB, and many of the key polyunsaturated fatty acids (PUFA), like C18:2 n-6 and C18:3 n-3, linearly increased (P<0.001), but not those of C20:5 n-3 and C22:6 n-3. There were linear decreases (P<0.001) in hepatic abundance of FAS and SREBP1 transcripts, with a substantial reduction to about 30% those of ducks fed the control diet; there were no treatment effects on productive performance, eggshell thickness, strength, Haugh unit, antioxidation status, and egg yolk cholesterol or triglyceride content (P>0.05). In conclusion, the current study suggests that ducks from 19 to 31 wk could be fed diets with up to about 18% RB without effect on the number of eggs produced, egg quality, and oxidative status. Increasing amounts of RB linearly increased egg yolk concentrations of key fatty acids like C18:2 n-6 and C18:3 n-3 and decreased the hepatic abundance of FAS and SREBP-1 transcripts.

  3. Acid Base Titrations in Nonaqueous Solvents and Solvent Mixtures

    NASA Astrophysics Data System (ADS)

    Barcza, Lajos; Buvári-Barcza, Ágnes

    2003-07-01

    The acid base determination of different substances by nonaqueous titrations is highly preferred in pharmaceutical analyses since the method is quantitative, exact, and reproducible. The modern interpretation of the reactions in nonaqueous solvents started in the last century, but several inconsistencies and unsolved problems can be found in the literature. The acid base theories of Brønsted Lowry and Lewis as well as the so-called solvent theory are outlined first, then the promoting (and leveling) and the differentiating effects are discussed on the basis of the hydrogen-bond concept. Emphasis is put on the properties of formic acid and acetic anhydride since their importance is increasing.

  4. Maternal Vitamin D, Folate, and Polyunsaturated Fatty Acid Status and Bacterial Vaginosis during Pregnancy

    PubMed Central

    Dunlop, Anne L.; Taylor, Robert N.; Tangpricha, Vin; Fortunato, Stephen; Menon, Ramkumar

    2011-01-01

    Objective. To investigate associations among serum 25-hydroxy-vitamin D (25-OH-D), folate, omega-6/omega-3 fatty acid ratio and bacterial vaginosis (BV) during pregnancy. Methods. Biospecimens and data were derived from a random sample (N = 160) of women from the Nashville Birth Cohort. We compared mean plasma nutrient concentrations for women with and without BV during pregnancy (based on Nugent score ≥7) and assessed the odds of BV for those with 25-OH-D <12 ng/mL, folate <5 ug/L, and omega-6/omega-3 ratio >15. Results. The mean plasma 25-OH-D was significantly lower among women with BV during pregnancy (18.00±8.14 ng/mL versus 24.34±11.97 ng/mL, P = 0.044). The adjusted odds of BV were significantly increased among pregnant women with 25-OH-D <12 ng/mL (aOR 5.11, 95% CI: 1.19–21.97) and folate <5 ug/L (aOR 7.06, 95% CI: 1.07–54.05). Conclusion. Vitamin D and folate deficiencies were strongly associated with BV (Nugent score ≥7) during pregnancy. PMID:22190843

  5. An Acid-Base Chemistry Example: Conversion of Nicotine

    NASA Astrophysics Data System (ADS)

    Summerfield, John H.

    1999-10-01

    The current government interest in nicotine conversion by cigarette companies provides an example of acid-base chemistry that can be explained to students in the second semester of general chemistry. In particular, the conversion by ammonia of the +1 form of nicotine to the easier-to-assimilate free-base form illustrates the effect of pH on acid-base equilibrium. The part played by ammonia in tobacco smoke is analogous to what takes place when cocaine is "free-based".

  6. Characterisation of acid-base abnormalities in pigs experimentally infected with Chlamydia suis.

    PubMed

    Reinhold, Petra; Hartmann, Helmut; Constable, Peter D

    2010-05-01

    This study characterises the acid-base abnormalities in pigs experimentally infected with Chlamydia suis (Henderson-Hasselbalch equation and Constable's simplified strong ion equation). Eight pigs were challenged with the respiratory pathogen C. suis and four pigs served as non-infected controls. Pigs were monitored from 7 days before challenge to 8 days post-inoculation. Clinical examination was performed twice daily and venous blood samples were collected every two days. Blood-gas analysis, haemoxymetry, serum biochemical analysis and electrophoresis were performed in order to characterise the acid-base derangement. Aerosol challenge with C. suis resulted in severe acid-base disturbance characterised by acute respiratory acidosis and strong ion (metabolic) acidosis secondary to anaerobic metabolism and hyper L-lactataemia. Maximal changes were seen at day 3 post-inoculation when severe clinical signs of respiratory dysfunction were evident. The results of the study provide new information regarding the pathophysiology of respiratory infection caused by C. suis and the applicability and diagnostic utility of different approaches for assessing acid-base status in pigs.

  7. High-fat diet lowers the nutritional status indicators of pantothenic acid in weaning rats.

    PubMed

    Yoshida, Erina; Fukuwatari, Tsutomu; Ohtsubo, Masako; Shibata, Katsumi

    2010-01-01

    Weaning rats were fed a 5% or 30% fat diet containing limited calcium pantothenate for 28 d. The plasma, liver and adrenal pantothenic acid levels in the rats fed on the 30% fat diet were significantly lower than with the 5% fat diet. The results suggest that the high-fat diet affected pantothenic acid metabolism. PMID:20699566

  8. Bio-production of lactobionic acid: current status, applications and future prospects.

    PubMed

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2013-12-01

    Lactobionic acid has appeared on the commercial scene as a versatile polyhydroxy acid with numerous promising applications in the food, medicine, pharmaceutical, cosmetics and chemical industries. This high value-added bio-product has recently received growing attention as a bioactive compound, providing an excellent chemical platform for the synthesis of novel potentially biocompatible and biodegradable drug delivery vehicles. Recent advances in tissue engineering and nanomedicine have also underlined the increased importance of this organic acid as a key biofunctionalization agent. The growing commercial relevance of lactobionic acid has therefore prompted the development of novel systems for its biotechnological production that are both sustainable and efficient. The present review explores recent advances and studies related to lactobionic acid bio-production, whether through microbial or enzymatic approaches, highlighting the key bioprocessing conditions for enhanced bio-production. Detailed overviews of the current microbial cell factories as well as downstream processing methodologies for lactobionic acid production are also presented. Furthermore, the potential prospects and current applications of this polyhydroxy acid are also discussed, with an emphasis on the role of lactobionic acid as a key platform in the development of novel drugs, biomaterials, nanoparticles and biopolymer systems.

  9. Biotechnological production of alpha-keto acids: Current status and perspectives.

    PubMed

    Song, Yang; Li, Jianghua; Shin, Hyun-Dong; Liu, Long; Du, Guocheng; Chen, Jian

    2016-11-01

    Alpha-keto (α-keto) acids are used widely in feeds, food additives, pharmaceuticals, and in chemical synthesis processes. Although most α-keto acids are currently produced by chemical synthesis, their biotechnological production from renewable carbohydrates is a promising new approach. In this mini-review, we first present the different types of α-keto acids as well as their applications; next, we summarize the recent progresses in the biotechnological production of some important α-keto acids; namely, pyruvate, α-ketoglutarate, α-ketoisovalerate, α-ketoisocaproate, phenylpyruvate, α-keto-γ-methylthiobutyrate, and 2,5-diketo-d-gluconate. Finally, we discuss the future prospects as well as favorable directions for the biotechnological production of keto acids that ultimately would be more environment-friendly and simpler compared with the production by chemical synthesis.

  10. Biotechnological production of alpha-keto acids: Current status and perspectives.

    PubMed

    Song, Yang; Li, Jianghua; Shin, Hyun-Dong; Liu, Long; Du, Guocheng; Chen, Jian

    2016-11-01

    Alpha-keto (α-keto) acids are used widely in feeds, food additives, pharmaceuticals, and in chemical synthesis processes. Although most α-keto acids are currently produced by chemical synthesis, their biotechnological production from renewable carbohydrates is a promising new approach. In this mini-review, we first present the different types of α-keto acids as well as their applications; next, we summarize the recent progresses in the biotechnological production of some important α-keto acids; namely, pyruvate, α-ketoglutarate, α-ketoisovalerate, α-ketoisocaproate, phenylpyruvate, α-keto-γ-methylthiobutyrate, and 2,5-diketo-d-gluconate. Finally, we discuss the future prospects as well as favorable directions for the biotechnological production of keto acids that ultimately would be more environment-friendly and simpler compared with the production by chemical synthesis. PMID:27575335

  11. Effects of increased dietary sulfur on beef steer mineral status, performance, and meat fatty acid composition.

    PubMed

    Richter, E L; Drewnoski, M E; Hansen, S L

    2012-11-01

    Ninety-six crossbred yearling steers (321 ± 29 kg BW) were used to determine the effects of feeding cattle a high S diet on pasture before receiving a high S diet in the feedlot. Steers were blocked by BW, allocated to 2.4-ha bromegrass (Bromus inermis L.) pastures (n = 4 plots per treatment), and supplemented at 1% BW with either low S dried distillers grains with solubles (DDGS; 0.34% total diet S; LS) or LS DDGS with additional S (0.47% total diet S; HS) from NaSO(4) for 36 d. On d 37, steers moved into the feedlot where one-half remained on the previous S treatment and the other half switched treatments, resulting in 4 treatments (LS-LS, LS-HS, HS-LS, HS-HS; LS: 0.2 to 0.3% total diet S, HS: 0.5 to 0.6% total diet S; n = 6 feedlot pens per treatment). During the pasture period, forage mass offered, grazing residual mass, and in vitro digestible DM of forage did not differ among treatments (P > 0.40), and ADG did not differ (LS: 1.6 kg · d(-1), HS: 1.7 kg · d(-1), P = 0.54). Plasma Mg measured on d 35 was decreased by ≈ 5% in response to increased dietary S during the pasture period (P = 0.05), though no effect on plasma Mg was observed during finishing (P > 0.15). Plasma Cu concentrations on d 155 were ≈ 15% less (P = 0.02) in HS vs. LS steers, and d 155 liver Cu concentrations were ≈ 51% less in HS vs. LS steers (P = 0.01). Increased dietary S during the feedlot period decreased ADG by ≈ 10% (P = 0.01) and tended to decrease HCW by ≈ 5% (P = 0.06) compared with LS steers. Steers receiving the HS diet had increased stearic acid (C18:0) and heptadecanoic acid (C17:0; P = 0.04 and 0.01, respectively) percentages in rib facings collected at slaughter. Exposing cattle to greater S diets (0.47% S) during a forage-based diet did not influence later performance on high S feedlot diets (0.5 to 0.6% S); however, cattle fed high dietary S on pasture had greater fat cover at slaughter (P = 0.01), suggesting S may have influenced lipid metabolism.

  12. Salicylic acid-induced elicitation of folates in coriander (Coriandrum sativum L.) improves bioaccessibility and reduces pro-oxidant status.

    PubMed

    Puthusseri, Bijesh; Divya, Peethambaran; Lokesh, Veeresh; Neelwarne, Bhagyalakshmi

    2013-01-15

    Foliage of Coriandrum sativum is a rich source of natural folates amenable for enhancement through salicylic acid-mediated elicitation, thereby holding a great promise for natural-mode alleviation of this vitamin (B(9)) deficiency. In the present study we report salicylic acid-mediated differential elicitation of different forms of folates - 5-methyltetrahydrofolate, 5-formyltetrahydrofolate and 10-formyltetrahydrofolate - their stabilities during microwave-drying and bioaccessibilities from fresh and dried foliage. The first two compounds nearly doubled and the third increased sixfold post-elicitation, with all three showing concomitant increase in bioaccessibilities. Although a slight decrease in bioaccessibility was observed in dried foliage, over twofold increase of each form of folate upon elicitation would deliver much higher levels of natural folates from this traditional culinary foliage, which is widely used in many cuisines. Elicitor-mediated folate enhancement also imparted reduction of oxidative status and the enhancement of antioxidant enzyme activities in coriander foliage.

  13. Folate Catabolites in Spot Urine as Non-Invasive Biomarkers of Folate Status during Habitual Intake and Folic Acid Supplementation

    PubMed Central

    Niesser, Mareile; Demmelmair, Hans; Weith, Thea; Moretti, Diego; Rauh-Pfeiffer, Astrid; van Lipzig, Marola; Vaes, Wouter; Koletzko, Berthold; Peissner, Wolfgang

    2013-01-01

    Background Folate status, as reflected by red blood cell (RCF) and plasma folates (PF), is related to health and disease risk. Folate degradation products para-aminobenzoylglutamate (pABG) and para-acetamidobenzoylglutamate (apABG) in 24 hour urine have recently been shown to correlate with blood folate. Aim Since blood sampling and collection of 24 hour urine are cumbersome, we investigated whether the determination of urinary folate catabolites in fasted spot urine is a suitable non-invasive biomarker for folate status in subjects before and during folic acid supplementation. Study Design and Methods Immediate effects of oral folic acid bolus intake on urinary folate catabolites were assessed in a short-term pre-study. In the main study we included 53 healthy men. Of these, 29 were selected for a 12 week folic acid supplementation (400 µg). Blood, 24 hour and spot urine were collected at baseline and after 6 and 12 weeks and PF, RCF, urinary apABG and pABG were determined. Results Intake of a 400 µg folic acid bolus resulted in immediate increase of urinary catabolites. In the main study pABG and apABG concentrations in spot urine correlated well with their excretion in 24 hour urine. In healthy men consuming habitual diet, pABG showed closer correlation with PF (rs = 0.676) and RCF (rs = 0.649) than apABG (rs = 0.264, ns and 0.543). Supplementation led to significantly increased folate in plasma and red cells as well as elevated urinary folate catabolites, while only pABG correlated significantly with PF (rs = 0.574) after 12 weeks. Conclusion Quantification of folate catabolites in fasted spot urine seems suitable as a non-invasive alternative to blood or 24 hour urine analysis for evaluation of folate status in populations consuming habitual diet. In non-steady-state conditions (folic acid supplementation) correlations between folate marker (RCF, PF, urinary catabolites) decrease due to differing kinetics. PMID:23457526

  14. Status of the DNB based ITER CXRS and BES diagnostic

    NASA Astrophysics Data System (ADS)

    von Hellermann, M.; Jaspers, R.; Biel, W.; Litnovsky, A.; Neubauer, O.; Pap, M.; Hawkes, N. C.; Marren, C.; Walton, B.; Kaschuck, Y.; Serov, V.; Tugarinov, S.; Vliegenthart, W.; Moddemeijer, K.; Walker, C.; Ingesson, C.

    2006-10-01

    A status report is given on recent joint activities on the ITER CXRS and BES diagnostic package. Expected measurement performances are reviewed as well as comprehensive discussions are led on an integral approach to the implementation of Core and Edge CXRS observation periscopes. The "first mirror" location, its operational temperature, maintenance issues, and optimization of optical imaging are addressed. In parallel to more technical aspects, particular attention has also been given to the development of common evaluation and modeling tools. One part of this work is linked to the modeling of spectra for existing fusion devices and their CXRS diagnostics and extrapolation to the ITER environment. The purpose of this effort is to provide tools for the optimization of spectroscopic instrumentation, and moreover, the specifications of a suitable diagnostic beam.

  15. Effect of functional buffalo cheese on fatty acid profile and oxidative status of liver and intestine of mice.

    PubMed

    Van Nieuwenhove, Carina P; Cano, Paola Gauffin; Pérez-Chaia, Adriana B; González, Silvia N

    2011-04-01

    The objective of this study was to determine the influence of administration of buffalo dairy products on lipid content and conjugated linoleic acid (CLA) incorporation on liver and intestine of mice. Buffalo cheeses were selected according to nutritional properties and CLA content. Cheeses were previously manufactured using as adjunct culture bacteria with probiotic or technological properties. BALB/c mice were fed for 28 days, and then a single dose of 1,2-dimethylhydrazine (DMH) as oxidant agent was administered before the influence of diet and DMH on antioxidant status in tissues was evaluated. Mice fed buffalo cheese showed the highest body weight gain (P < .05). Polyunsaturated fatty acid (PUFA) content in foods was very different, but total PUFA incorporation was similar in mouse tissues. CLA was only detected in fat tissues of mice fed dairy products, with cis-9, trans-11 being the major isomer. A higher linolenic (C(18:3)) acid content was found in tissues of mice fed commercial diet (control group), and it was partially replaced by CLA in groups receiving buffalo milk or cheese. Lipoperoxides (thiobarbituric acid-reactive substances) were higher in tissues of the control group with or without DMH administration, and DMH had a cytotoxic effect on colon cells (P < .05). Superoxide dismutase (SOD) and catalase activities in liver and intestine were similar among animals, with a slight increase of SOD detected after DMH treatment. Consumption of buffalo dairy products did not affect the oxidative status of mice tissues even after DMH application. In the present study, a protective effect of buffalo cheese and milk on intestine cells was determined. PMID:21370968

  16. Undernutrition, fatty acid and micronutrient status in relation to cognitive performance in Indian school children: a cross-sectional study.

    PubMed

    Eilander, Ans; Muthayya, Sumithra; van der Knaap, Henk; Srinivasan, Krishnamachari; Thomas, Tinku; Kok, Frans J; Kurpad, Anura V; Osendarp, Saskia J M

    2010-04-01

    While undernutrition and anaemia have previously been linked to poor development of children, relatively little is known about the role of B-vitamins and fatty acids on cognition. The present study aims to explore the associations between indicators of body size, fatty acid and micronutrient status on cognitive performance in 598 Indian school children aged 6-10 years. Baseline data of a clinical study were used to assess these associations by analyses of variance adjusting for age, sex, school, maternal education and cognitive tester. The Kaufman Assessment Battery for Children II was used to measure four cognitive domains, including fluid reasoning, short-term memory, retrieval ability and cognitive speediness. Scores were combined into an overall measure, named mental processing index (MPI). Body size indicators and Hb concentrations were significantly positively related to cognitive domains and MPI, such that increases of 1 sd in height-for-age and weight-for-age z-scores would each translate into a 0.09 sd increase in MPI, P = 0.0006 and 0.002, respectively. A 10 g/l increase in Hb concentrations would translate into a 0.08 sd increase in MPI, P = 0.0008. Log-transformed vitamin B12 concentrations were significantly inversely associated with short-term memory, retrieval ability and MPI (beta (95 % CI) = - 0.124 (- 0.224, - 0.023), P = 0.02). Other indicators of Fe, iodine, folate and fatty acid status were not significantly related to cognition. Our findings for body size, fatty acids and micronutrients were in agreement with previous observational studies. The inverse association of vitamin B12 with mental development was unexpected and needed further study. PMID:20003612

  17. Roles of urea production, ammonium excretion, and amino acid oxidation in acid-base balance.

    PubMed

    Mackenzie, W

    1986-02-01

    Atkinson and colleagues recently proposed several concepts that contrast with traditional views: first, that acid-base balance is regulated chiefly by the reactions leading to urea production in the liver; second, that ammonium excretion by the kidney plays no role in acid-base homeostasis; and third, that ammonium does not stimulate ureagenesis (except indirectly). To examine these concepts, plasma ions other than bicarbonate are categorized as 1) fixed cations (Na+, K+, Ca2+, and Mg2+, symbolized M+) and anions (Cl-), 2) buffer anions (A-), 3) other anions (X-), and 4) ammonium plus charged amino groups (N+). Since electroneutrality dictates that M+ + N+ = Cl- + HCO3- + A- + X-, it follows that delta HCO3- = delta(M+ - Cl-) - delta A- - delta X- + delta N+. Therefore acid-base disturbances (changes in HCO3-) can be categorized as to how they affect bodily content and hence plasma concentration of each of these four types of ions. The stoichiometry of ureagenesis, glutamine hydrolysis, ammonium and titratable acid excretion, oxidation of neutral, acidic, and basic amino acids, and oxidation of methionine, phosphoserine, and protein are examined to see how they alter these quantities. It is concluded that 1) although ureagenesis is pH dependent and also counteracts a tendency of amino acid oxidation to cause alkalosis, this tendency is inherently limited by the hyperammonemia (delta N+) that necessarily accompanies it, 2) ammonium excretion is equivalent to hydrogen excretion in its effects on acid-base balance if, and only if, it occurs in exchange for sodium or is accompanied by chloride excretion and only when the glutamate generated by glutamine hydrolysis is oxidized.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3511732

  18. Achieving optimal n-3 fatty acid status: the vegetarian's challenge... or not.

    PubMed

    Harris, William S

    2014-07-01

    The long chain n-3 (omega-3) fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), although originally synthesized by microorganisms in the oceans, are primarily obtained from the consumption of fish. Vegetarians, by definition, do not eat fish and thus consume virtually no EPA and DHA. Because conversion of the plant-derived n-3 fatty acid α-linolenic acid (ALA) to EPA and DHA is very low, n-3 tissue concentrations in vegetarians are lower than in omnivores. This review asks 2 questions: what is the evidence that increased n-3 concentrations reduce the risk of cardiovascular disease in vegetarians, and, if it does, how can vegetarians increase their blood and tissue concentrations of these animal-derived fatty acids? At present, both cardiovascular risk markers and cardiovascular events appear to be significantly reduced in vegetarians compared with those in omnivores. If so, and in the absence of data to show that risk in vegetarians could be even lower with higher n-3 concentrations, then the second question becomes moot. However, the absence of evidence is not evidence of absence; therefore, at our present state of knowledge, increasing n-3 concentrations is not an unreasonable goal for vegetarians. This can be accomplished by a variety of approaches, including increased intakes of ALA, consumption of stearidonic acid-enriched soybean oil (if and when it comes to the market), and the use of supplements containing EPA, DHA, or both derived from nonanimal sources (microalgae, biotech yeast, and, in the future, biotech plant oils).

  19. Dietary zinc deficiency affects blood linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio; a sensitive physiological marker of zinc status in vivo (Gallus gallus).

    PubMed

    Reed, Spenser; Qin, Xia; Ran-Ressler, Rinat; Brenna, James Thomas; Glahn, Raymond P; Tako, Elad

    2014-03-20

    Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. To date, sensitive and specific biological markers of zinc status are still needed. The aim of this study was to evaluate Gallus gallus as an in vivo model in the context of assessing the sensitivity of a previously unexplored potential zinc biomarker, the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio. Diets identical in composition were formulated and two groups of birds (n = 12) were randomly separated upon hatching into two diets, Zn⁺ (zinc adequate control, 42.3 μg/g zinc), and Zn⁻ (zinc deficient, 2.5 μg/g zinc). Dietary zinc intake, body weight, serum zinc, and the erythrocyte fatty acid profile were measured weekly. At the conclusion of the study, tissues were collected for gene expression analysis. Body weight, feed consumption, zinc intake, and serum zinc were higher in the Zn⁺ control versus Zn⁻ group (p < 0.05). Hepatic TNF-α, IL-1β, and IL-6 gene expression were higher in the Zn⁺ control group (p < 0.05), and hepatic Δ⁶ desaturase was significantly higher in the Zn⁺ group (p < 0.001). The LA:DGLA ratio was significantly elevated in the Zn⁻ group compared to the Zn⁺ group (22.6 ± 0.5 and 18.5 ± 0.5, % w/w, respectively, p < 0.001). This study suggests erythrocyte LA:DGLA is able to differentiate zinc status between zinc adequate and zinc deficient birds, and may be a sensitive biomarker to assess dietary zinc manipulation.

  20. Dietary Zinc Deficiency Affects Blood Linoleic Acid: Dihomo-γ-linolenic Acid (LA:DGLA) Ratio; a Sensitive Physiological Marker of Zinc Status in Vivo (Gallus gallus)

    PubMed Central

    Reed, Spenser; Qin, Xia; Ran-Ressler, Rinat; Brenna, James Thomas; Glahn, Raymond P.; Tako, Elad

    2014-01-01

    Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. To date, sensitive and specific biological markers of zinc status are still needed. The aim of this study was to evaluate Gallus gallus as an in vivo model in the context of assessing the sensitivity of a previously unexplored potential zinc biomarker, the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio. Diets identical in composition were formulated and two groups of birds (n = 12) were randomly separated upon hatching into two diets, Zn(+) (zinc adequate control, 42.3 μg/g zinc), and Zn(−) (zinc deficient, 2.5 μg/g zinc). Dietary zinc intake, body weight, serum zinc, and the erythrocyte fatty acid profile were measured weekly. At the conclusion of the study, tissues were collected for gene expression analysis. Body weight, feed consumption, zinc intake, and serum zinc were higher in the Zn(+) control versus Zn(−) group (p < 0.05). Hepatic TNF-α, IL-1β, and IL-6 gene expression were higher in the Zn(+) control group (p < 0.05), and hepatic Δ6 desaturase was significantly higher in the Zn(+) group (p < 0.001). The LA:DGLA ratio was significantly elevated in the Zn(−) group compared to the Zn(+) group (22.6 ± 0.5 and 18.5 ± 0.5, % w/w, respectively, p < 0.001). This study suggests erythrocyte LA:DGLA is able to differentiate zinc status between zinc adequate and zinc deficient birds, and may be a sensitive biomarker to assess dietary zinc manipulation. PMID:24658588

  1. Role of acids and bases in nanoparticle growth

    NASA Astrophysics Data System (ADS)

    Yli-Juuti, Taina; Barsanti, Kelley; Bzdek, Bryan; Hildebrandt Ruiz, Lea; Jokinen, Tuija; Kieloaho, Antti-Jussi; Makkonen, Ulla; Petäjä, Tuukka; Ruuskanen, Taina; Johnston, Murray; Kulmala, Markku; Riipinen, Ilona

    2014-05-01

    Secondary aerosol particles that are formed in atmosphere by gas-to-particle conversion during new particle formation events have potential to affect climate significantly due to their typically high number concentrations. This, however, requires that the freshly formed nanoparticles of about 1 nm in diameter grow tens of nanometers and reach climatically relevant sizes, i.e. sizes where they can act as cloud condensation nuclei. During the growth towards larger sizes the nanoparticles are subject to coagulational losses, and the rate at which the nanoparticles grow by condensation of vapors is a key factor affecting their probability to survive to climatically relevant sizes. Vapors that condense on the nanoparticles can be produced in the atmosphere from volatile compounds through gas phase chemical reactions, and their volatility can also be further lowered by particle phase processes. Therefore, particle composition and particle phase processes may influence nanoparticle growth. We study the growth of atmospheric nanoparticles and especially the role of particle phase salt formation in the nanoparticle growth using MABNAG model (Model for Acid-Base chemistry in NAnoparticle Growth) and by comparing to atmospheric measurements. MABNAG is a condensation growth model for aqueous solution particles. In MABNAG the dynamics of gas phase mass transport of vapors to particle are coupled with thermodynamics of particle phase acid-base chemistry, and both the composition and size dependence of equilibrium vapor pressures are accounted for. The model is applied especially for boreal forest environment. Here nanoparticle growth is modeled with a system of water, two acids (sulfuric acid and an organic acid) and two bases (ammonia and an amine) as condensing vapors. Focus is on the neutralization of acids by the bases and the related effects on the particle growth. According to the model predictions the enhancement of condensation of organic acid due to salt formation is

  2. Poly (ricinoleic acid) based novel thermosetting elastomer.

    PubMed

    Ebata, Hiroki; Yasuda, Mayumi; Toshima, Kazunobu; Matsumura, Shuichi

    2008-01-01

    A novel bio-based thermosetting elastomer was prepared by the lipase-catalyzed polymerization of methyl ricinoleate with subsequent vulcanization. Some mechanical properties of the cured carbon black-filled polyricinoleate compounds were evaluated as a thermosetting elastomer. It was found that the carbon black-filled polyricinoleate compounds were readily cured by sulfur curatives to produce a thermosetting elastomer that formed a rubber-like sheet with a smooth and non-sticky surface. The curing behaviors and mechanical properties were dependent on both the molecular weight of the polyricinoleate and the amount of the sulfur curatives. Cured compounds consisting of polyricinoleate with a molecular weight of 100,800 showed good mechanical properties, such as a hardness of 48 A based on the durometer A measurements, a tensile strength at break of 6.91 MPa and an elongation at break of 350%. PMID:18469493

  3. Margarines fortified with α-linolenic acid, eicosapentaenoic acid, or docosahexaenoic acid alter the fatty acid composition of erythrocytes but do not affect the antioxidant status of healthy adults.

    PubMed

    Egert, Sarah; Lindenmeier, Michael; Harnack, Kerstin; Krome, Katharina; Erbersdobler, Helmut F; Wahrburg, Ursel; Somoza, Veronika

    2012-09-01

    We aimed to investigate the effects of increased intake of α-linolenic acid (ALA), EPA, or DHA incorporated into a food matrix on the fatty acid composition of erythrocytes and on biomarkers of oxidant/antioxidant status. To this end, a controlled dietary study was conducted in 74 healthy men and women. The participants were randomly assigned to 1 of 3 interventions in which margarines fortified with either 10 weight percent ALA, EPA, or DHA ethyl esters replaced their normal spread for 6 wk. The total intakes of ALA, EPA, and DHA were 4.4, 2.2, and 2.3 g/d, respectively. Consuming EPA increased the erythrocyte proportion of EPA (394%) and the omega-3 index (sum of EPA and DHA, 38%). Consumption of DHA increased erythrocyte DHA (91%), the omega-3 index (98%), and EPA (137%). The omega-3 index increased to a significantly greater extent in the DHA group than in the EPA group. ALA did not increase erythrocyte EPA or the omega-3 index. We found no change in plasma uric acid or antioxidant capacity in any of the groups. Plasma malondialdehyde (MDA) increased with the EPA and DHA interventions. All 3 interventions decreased erythrocyte linoleic acid hydroperoxides but did not affect their MDA concentrations. In conclusion, the intake of both isolated EPA and DHA incorporated into margarine resulted in an enhanced incorporation of EPA and DHA into erythrocytes. Our findings indicate that DHA is quantitatively superior to EPA in view of the EPA+DHA tissue incorporation and also that 4 g/d ALA is not sufficient to increase the omega-3 index over a 6-wk period.

  4. Relationships among Subjective Social Status, Weight Perception, Weight Control Behaviors, and Weight Status in Adolescents: Findings from the 2009 Korea Youth Risk Behaviors Web-Based Survey

    ERIC Educational Resources Information Center

    Ha, Yeongmi; Choi, Eunsook; Seo, Yeongmi; Kim, Tae-gu

    2013-01-01

    Background: This study identified relationships among subjective social status (SSS), weight perception, weight control behaviors, and weight status in Korean adolescents using nationally representative data collected from the 2009 Korea Youth Risk Behaviors Web-Based Survey. Methods: Data from 67,185 students aged 12-18 years were analyzed.…

  5. NASA/RAE cooperation on a knowlede based flight status monitor

    NASA Technical Reports Server (NTRS)

    Butler, G. F.; Duke, E. L.

    1989-01-01

    As part of a US/UK cooperative aeronautical research pragram, a joint activity between the Dryden Flight Research Facility of the NASA Ames Research Center (Ames-Dryden) and the Royal Aerospace Establishment (RAE) on Knowledge Based Systems was established. Under the agreement, a Flight Status Monitor Knowledge base developed at Ames-Dryden was implemented using the real-time IKBS toolkit, MUSE, which was developed in the UK under RAE sponsorship. The Flight Status Monitor is designed to provide on-line aid to the flight test engineer in the interpretation of system health and status by storing expert knowledge of system behavior in an easily accessible form. The background to the cooperation is described and the details of the Flight Status Monitor, the MUSE implementation are presented.

  6. Micellar acid-base potentiometric titrations of weak acidic and/or insoluble drugs.

    PubMed

    Gerakis, A M; Koupparis, M A; Efstathiou, C E

    1993-01-01

    The effect of various surfactants [the cationics cetyl trimethyl ammonium bromide (CTAB) and cetyl pyridinium chloride (CPC), the anionic sodium dodecyl sulphate (SDS), and the nonionic polysorbate 80 (Tween 80)] on the solubility and ionization constant of some sparingly soluble weak acids of pharmaceutical interest was studied. Benzoic acid (and its 3-methyl-, 3-nitro-, and 4-tert-butyl-derivatives), acetylsalicylic acid, naproxen and iopanoic acid were chosen as model examples. Precise and accurate acid-base titrations in micellar systems were made feasible using a microcomputer-controlled titrator. The response curve, response time and potential drift of the glass electrode in the micellar systems were examined. The cationics CTAB and CPC were found to increase considerably the ionization constant of the weak acids (delta pKa ranged from -0.21 to -3.57), while the anionic SDS showed negligible effect and the nonionic Tween 80 generally decreased the ionization constants. The solubility of the acids in aqueous micellar and acidified micellar solutions was studied spectrophotometrically and it was found increased in all cases. Acetylsalicylic acid, naproxen, benzoic acid and iopanoic acid could be easily determined in raw material and some of them in pharmaceutical preparations by direct titration in CTAB-micellar system instead of using the traditional non-aqueous or back titrimetry. Precisions of 0.3-4.3% RSD and good correlation with the official tedious methods were obtained. The interference study of some excipients showed that a preliminary test should be carried out before the assay of formulations.

  7. Soil Studies: Applying Acid-Base Chemistry to Environmental Analysis.

    ERIC Educational Resources Information Center

    West, Donna M.; Sterling, Donna R.

    2001-01-01

    Laboratory activities for chemistry students focus attention on the use of acid-base chemistry to examine environmental conditions. After using standard laboratory procedures to analyze soil and rainwater samples, students use web-based resources to interpret their findings. Uses CBL probes and graphing calculators to gather and analyze data and…

  8. High School Students' Concepts of Acids and Bases.

    ERIC Educational Resources Information Center

    Ross, Bertram H. B.

    An investigation of Ontario high school students' understanding of acids and bases with quantitative and qualitative methods revealed misconceptions. A concept map, based on the objectives of the Chemistry Curriculum Guideline, generated multiple-choice items and interview questions. The multiple-choice test was administered to 34 grade 12…

  9. Foliar nutrient status of Pinus ponderosa exposed to ozone and acid rain

    SciTech Connect

    Anderson, P.D.; Houpis, J.L.J. )

    1991-05-01

    A direct effect of foliar exposure to acid rain may be increased leaching of nutrient elements. Ozone exposure, through degradation of the cuticle and cellular membranes, may also result in increased nutrient leaching. To test these hypotheses, the foliar concentrations of 13 nutrient elements were monitored for mature branches of three clones of Pinus ponderosa exposed to ozone and/or acid rain. The three clones represented three distinct levels of phenotypic vigor. Branches were exposed to charcoal filtered, ambient, or 2 x ambient concentrations of ozone and received no acid rain (NAP), pH 5.1 rain (5.1), or pH 3.0 (3.0) rain. Following 10 months of continuous ozone exposure and 3 months of weekly rain applications, the concentrations of P and Mg differed significantly among rain treatments with a ranking of: 5.1 < NAP < 3.0. The S concentration increased with rain application regardless of pH. For the clones of moderate and low vigor, the concentration of N decreased with increasing rain acidity. There was no evidence of significant ozone or ozone x acid rain response. Among the three families, high phenotypic vigor was associated with significantly greater concentrations of N, P, K, Mg, B and An. These results indicate generally negligible leaching as a result of exposure to acid rain and/or ozone for one growing season. Increases in foliar concentrations of S, Mg and P are possibly the result of evaporative surface deposition from the rain solution.

  10. Iron status of vegetarians.

    PubMed

    Craig, W J

    1994-05-01

    An appropriately planned well-balanced vegetarian diet is compatible with an adequate iron status. Although the iron stores of vegetarians may be reduced, the incidence of iron-deficiency anemia in vegetarians is not significantly different from that in omnivores. Restrictive vegetarian diets (eg, macrobiotic) are associated with more widespread iron-deficiency anemia. Western vegetarians who consume a variety of foods have a better iron status than do those in developing countries who consume a limited diet based on unleavened, unrefined cereals. Whereas phytates, polyphenolics, and other plant constituents found in vegetarian diets inhibit nonheme-iron absorption, vitamin C, citric acid, and other organic acids facilitate nonheme-iron absorption.

  11. Community-based dietary phytate reduction and its effect on iron status in Malawian children.

    PubMed

    Manary, Mark J; Krebs, Nancy F; Gibson, Rosalind S; Broadhead, Robin L; Hambidge, K Michael

    2002-06-01

    This study describes a community-based method used in rural Malawi to remove dietary phytate, an inhibitor of iron absorption, and notes an improvement in the iron status of ten children who participated in the trial. Phytate was removed by soaking maize flour in excess water with phytase and decanting the water before cooking the flour. Iron status, as measured by soluble transferrin receptor and zinc protoporphyrin, was improved but not normal.

  12. Supplementation with micronutrients in addition to iron and folic acid does not further improve the hematologic status of pregnant women in rural Nepal.

    PubMed

    Christian, Parul; Shrestha, Jaibar; LeClerq, Steven C; Khatry, Subarna K; Jiang, Tianan; Wagner, Tracey; Katz, Joanne; West, Keith P

    2003-11-01

    Iron deficiency is one of the main causes of anemia during pregnancy, although other micronutrient deficiencies may play a role. We examined the effects of daily antenatal and postnatal supplementation with four combinations of micronutrients on maternal hematologic indicators in a double-masked randomized controlled community trial. Communities, called sectors, were randomly assigned to supplementation with folic acid (400 microg), folic acid plus iron (60 mg), folic acid plus iron and zinc (30 mg) and folic acid plus iron, zinc and 11 other micronutrients, each at the approximate recommended daily allowance for pregnancy all given with vitamin A as retinol acetate (1000 microg retinol equivalent), or vitamin A alone as the control group. Hemoglobin (Hb) and indicators of iron status were assessed at baseline and at 32 wk of gestation. At 6-wk postpartum, Hb assessment was repeated using a finger stick. Severely anemic women (Hb < 70 g/L) were treated according to WHO recommendations. Folic acid alone had no effect on maternal anemia or iron status. Hb concentrations were 14 g/L, [95% confidence limits (CL), 8.3-19.2], 10.0 g/L (CL, 5.2-14.8) and 9.4 g/L (CL, 4.7-14.1) higher in the groups receiving folic acid plus iron, folic acid plus iron and zinc and folic acid plus iron, zinc and multiple micronutrients, respectively, relative to the control. Anemia in the third trimester was reduced by 54% with folic acid plus iron, by 48% with folic acid plus iron and zinc and by 36% with folic acid plus iron, zinc and multiple micronutrients supplementation, relative to the control (P < 0.05). Thus, the combinations of folic acid plus iron and zinc and folic acid plus iron, zinc and multiple micronutrients provided no additional benefit in improving maternal hematologic status during pregnancy compared with folic acid plus iron. The level of compliance and baseline Hb concentrations modified the effect of iron.

  13. A computational study of ultrafast acid dissociation and acid-base neutralization reactions. I. The model.

    PubMed

    Maurer, Patrick; Thomas, Vibin; Rivard, Ugo; Iftimie, Radu

    2010-07-28

    Ultrafast, time-resolved investigations of acid-base neutralization reactions have recently been performed using systems containing the photoacid 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) and various Bronsted bases. Two conflicting neutralization mechanisms have been formulated by Mohammed et al. [Science 310, 83 (2005)] and Siwick et al. [J. Am. Chem. Soc. 129, 13412 (2007)] for the same acid-base system. Herein an ab initio molecular dynamics based computational model is formulated, which is able to investigate the validity of the proposed mechanisms in the general context of ground-state acid-base neutralization reactions. Our approach consists of using 2,4,6-tricyanophenol (exp. pKa congruent with 1) as a model for excited-state HPTS( *) (pKa congruent with 1.4) and carboxylate ions for the accepting base. We employ our recently proposed dipole-field/quantum mechanics (QM) treatment [P. Maurer and R. Iftimie, J. Chem. Phys. 132, 074112 (2010)] of the proton donor and acceptor molecules. This approach allows one to tune the free energy of neutralization to any desired value as well as model initial nonequilibrium hydration effects caused by a sudden increase in acidity, making it possible to achieve a more realistic comparison with experimental data than could be obtained via a full-QM treatment of the entire system. It is demonstrated that the dipole-field/QM model reproduces correctly key properties of the 2,4,6-tricyanophenol acid molecule including gas-phase proton dissociation energies and dipole moments, and condensed-phase hydration structure and pKa values.

  14. A computational study of ultrafast acid dissociation and acid-base neutralization reactions. I. The model

    NASA Astrophysics Data System (ADS)

    Maurer, Patrick; Thomas, Vibin; Rivard, Ugo; Iftimie, Radu

    2010-07-01

    Ultrafast, time-resolved investigations of acid-base neutralization reactions have recently been performed using systems containing the photoacid 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) and various Brønsted bases. Two conflicting neutralization mechanisms have been formulated by Mohammed et al. [Science 310, 83 (2005)] and Siwick et al. [J. Am. Chem. Soc. 129, 13412 (2007)] for the same acid-base system. Herein an ab initio molecular dynamics based computational model is formulated, which is able to investigate the validity of the proposed mechanisms in the general context of ground-state acid-base neutralization reactions. Our approach consists of using 2,4,6-tricyanophenol (exp. pKa≅1) as a model for excited-state HPTS∗ (pKa≅1.4) and carboxylate ions for the accepting base. We employ our recently proposed dipole-field/quantum mechanics (QM) treatment [P. Maurer and R. Iftimie, J. Chem. Phys. 132, 074112 (2010)] of the proton donor and acceptor molecules. This approach allows one to tune the free energy of neutralization to any desired value as well as model initial nonequilibrium hydration effects caused by a sudden increase in acidity, making it possible to achieve a more realistic comparison with experimental data than could be obtained via a full-QM treatment of the entire system. It is demonstrated that the dipole-field/QM model reproduces correctly key properties of the 2,4,6-tricyanophenol acid molecule including gas-phase proton dissociation energies and dipole moments, and condensed-phase hydration structure and pKa values.

  15. Acid-base properties of humic and fulvic acids formed during composting.

    PubMed

    Plaza, César; Senesi, Nicola; Polo, Alfredo; Brunetti, Gennaro

    2005-09-15

    The soil acid-base buffering capacity and the biological availability, mobilization, and transport of macro- and micronutrients, toxic metal ions, and xenobiotic organic cations in soil are strongly influenced by the acid-base properties of humic substances, of which humic and fulvic acids are the major fractions. For these reasons, the proton binding behavior of the humic acid-like (HA) and fulvic acid-like (FA) fractions contained in a compost are believed to be instrumental in its successful performance in soil. In this work, the acid-base properties of the HAs and FAs isolated from a mixture of the sludge residue obtained from olive oil mill wastewater (OMW) evaporated in an open-air pond and tree cuttings (TC) at different stages of composting were investigated by a current potentiometric titration method and the nonideal competitive adsorption (NICA)-Donnan model. The NICA-Donnan model provided an excellent description of the acid-base titration data, and pointed out substantial differences in site density and proton-binding affinity between the HAs and FAs examined. With respect to FAs, HAs were characterized by a smaller content of carboxylic- and phenolic-type groups and their larger affinities for proton binding. Further, HAs featured a greater heterogeneity in carboxylic-type groups than FAs. The composting process increased the content and decreased the proton affinity of carboxylic- and phenolic-type groups of HAs and FAs, and increased the heterogeneity of phenolic-type groups of HAs. As a whole, these effects indicated that the composting process could produce HA and FA fractions with greater cation binding capacities. These results suggest that composting of organic materials improves their agronomic and environmental value by increasing their potential to retain and exchange macro- and micronutrients, and to reduce the bioavailability of organic and inorganic pollutants.

  16. Relationships between n-3 polyunsaturated fatty acid intake, serum 25 hydroxyvitamin D, food consumption, and nutritional status among adolescents.

    PubMed

    Lopes, Mariana P; Giudici, Kelly V; Marchioni, Dirce M; Fisberg, Regina M; Martini, Lígia A

    2015-08-01

    We have hypothesized that higher n-3 polyunsaturated fatty acid (PUFA) intake is associated with better lipid profile, higher 25 hydroxyvitamin D (25(OH)D) serum concentrations, and healthy food consumption and nutritional status. Thus, this study aimed to evaluate the relationships between n-3 PUFA intake, serum 25(OH)D, lipid profile, nutritional status, and food consumption among adolescents. A total of 198 Brazilian adolescents (51% male), with mean age of 16.3 ± 1.4 years, were enrolled in this cross-sectional study. Blood was collected for 25(OH)D and lipid profile serum measurement. Weight and height were measured, and food consumption was accessed by a 24-hour food record (n = 69). Analysis of variance, the Student t test, and Pearson correlation were performed using SPSS software (SPSS, Chicago, IL, USA). The prevalence of vitamin D inadequacy (25(OH)D, <30 ng/mL) was 71.7%. Serum 25(OH)D negatively correlated with body mass index (r = -0.294; P < .0001) and positively correlated with high-density lipoprotein cholesterol (r = 0.323; P < .0001). N-3 PUFA intake negatively correlated with body mass index (r = -0.286; P = .017), total cholesterol (r = -0.292; P = .015), and low-density lipoprotein cholesterol (r = -0.333; P = .005) and positively correlated with the intake of fat meats and eggs (r = 0.391; P = .006), vegetable proteins (r = 0.297; P = .048), fats/oils (r = 0.574; P < .001), and refined cereals (r = 0.351; P = .006). Vitamin D status and n-3 PUFA intake were related with better nutritional status and favorable lipid profile. Food groups usually found in Brazilian traditional meals (characterized by rice, beans, meat, and vegetables) were associated with higher n-3 PUFA intake, which may contribute to prevent the development of noncommunicable diseases in adolescence and adulthood. PMID:26094211

  17. N-3 polyunsaturated fatty acids supplementation does not affect changes of lipid metabolism induced in rats by altered thyroid status.

    PubMed

    Rauchová, H; Vokurková, M; Pavelka, S; Behuliak, M; Tribulová, N; Soukup, T

    2013-07-01

    Epidemiological studies have demonstrated that n-3 polyunsaturated fatty acid (PUFA) consumption is associated with a reduced risk of atherosclerosis and hyperlipidemia. It is well known that lipid metabolism is also influenced by thyroid hormones. The aim of our study was to test whether n-3 PUFA supplementation (200 mg/kg of body weight/day for 6 weeks given intragastrically) would affect lipid metabolism in Lewis male rats with altered thyroid status. Euthyroid, hypothyroid, and hyperthyroid status of experimental groups was well defined by plasma levels of triiodothyronine, the activity of liver mitochondrial glycerol-3-phosphate dehydrogenase, and by relative heart weight. Fasting blood glucose levels were significantly higher in the hyperthyroid compared to the euthyroid and hypothyroid rats (5.0±0.2 vs. 3.7±0.4 and 4.4±0.2 mmol/l, respectively). In hyperthyroid animals, the concentration of plasma postprandial triglycerides was also increased compared to euthyroid and hypothyroid rats (0.9±0.1 vs. 0.5±0.1 and 0.4±0.1 mmol/l, respectively). On the other hand, hypothyroidism compared to euthyroid and hyperthyroid status was associated with elevated plasma levels of total cholesterol (2.6±0.2 vs. 1.5±0.1 and 1.6±0.1 mmol/l, respectively), LDL cholesterol (0.9±0.1 vs. 0.4±0.1 and 0.2±0.1 mmol/l, respectively) as well as HDL cholesterol (1.6±0.1 vs. 1.0±0.1 and 1.3±0.1 mmol/l, respectively). Supplementation of n-3 PUFA in the present study did not significantly modify either relative heart weight or glucose and lipid levels in any thyroid status.

  18. Relationships between n-3 polyunsaturated fatty acid intake, serum 25 hydroxyvitamin D, food consumption, and nutritional status among adolescents.

    PubMed

    Lopes, Mariana P; Giudici, Kelly V; Marchioni, Dirce M; Fisberg, Regina M; Martini, Lígia A

    2015-08-01

    We have hypothesized that higher n-3 polyunsaturated fatty acid (PUFA) intake is associated with better lipid profile, higher 25 hydroxyvitamin D (25(OH)D) serum concentrations, and healthy food consumption and nutritional status. Thus, this study aimed to evaluate the relationships between n-3 PUFA intake, serum 25(OH)D, lipid profile, nutritional status, and food consumption among adolescents. A total of 198 Brazilian adolescents (51% male), with mean age of 16.3 ± 1.4 years, were enrolled in this cross-sectional study. Blood was collected for 25(OH)D and lipid profile serum measurement. Weight and height were measured, and food consumption was accessed by a 24-hour food record (n = 69). Analysis of variance, the Student t test, and Pearson correlation were performed using SPSS software (SPSS, Chicago, IL, USA). The prevalence of vitamin D inadequacy (25(OH)D, <30 ng/mL) was 71.7%. Serum 25(OH)D negatively correlated with body mass index (r = -0.294; P < .0001) and positively correlated with high-density lipoprotein cholesterol (r = 0.323; P < .0001). N-3 PUFA intake negatively correlated with body mass index (r = -0.286; P = .017), total cholesterol (r = -0.292; P = .015), and low-density lipoprotein cholesterol (r = -0.333; P = .005) and positively correlated with the intake of fat meats and eggs (r = 0.391; P = .006), vegetable proteins (r = 0.297; P = .048), fats/oils (r = 0.574; P < .001), and refined cereals (r = 0.351; P = .006). Vitamin D status and n-3 PUFA intake were related with better nutritional status and favorable lipid profile. Food groups usually found in Brazilian traditional meals (characterized by rice, beans, meat, and vegetables) were associated with higher n-3 PUFA intake, which may contribute to prevent the development of noncommunicable diseases in adolescence and adulthood.

  19. Deoxyribonucleic acid base compositions of dermatophytes.

    PubMed

    Davison, F D; Mackenzie, D W; Owen, R J

    1980-06-01

    DNA was extracted and purified from 55 dermatophyte isolates representing 34 species of Trichophyton, Microsporum and Epidermophyton. The base compositions of the chromosomal DNA were determined by CsCl density gradient centrifugation and were found to be in the narrow range of 48.7 to 50.3 mol % G + C. A satellite DNA component assumed to be of mitochondrial origin was present in most strains, with a G + C content ranging from 14.7 to 30.8 mol % G + C. Heterogeneity in microscopic and colonial characteristics was not reflected in differences in the mean G + C content of the chromosomal DNAs. Strains varied in the G + C contents of satelite DNA, but these did not correlate with traditional species concepts.

  20. Maternal and fetal Acid-base chemistry: a major determinant of perinatal outcome.

    PubMed

    Omo-Aghoja, L

    2014-01-01

    Very small changes in pH may significantly affect the function of various fetal organ systems, such as the central nervous system, and the cardiovascular system with associated fetal distress and poor Apgar score. Review of existing data on maternal-fetal acid-base balance in pregnancy highlight the factors that are associated with derangements of the acid-base status and the impact of the derangements on fetal outcome. Extensive search of electronic databases and manual search of journals for relevant literature on maternal and fetal acid chemistry, clinical studies and case studies were undertaken. There is a substantial reduction in the partial pressure of carbon dioxide (pCO2) in pregnancy. Adequate buffering prevents significant changes in maternal arterial pH. Normal fetal metabolism results in the production of acids which are buffered to maintain extracellular pH within a critical range. Fetal hypoxia can occur when maternal oxygenation is compromised, maternal perfusion of the placenta is reduced, or delivery of oxygenated blood from the placenta to the fetus is impeded. When adequate fetal oxygenation does not occur, metabolisms proceed along with an anaerobic pathway with production of organic acids, such as lactic acid. Accumulation of lactic acid can deplete the buffer system and result in metabolic acidosis with associated low fetal pH, fetal distress and poor Apgar score. There is a significant reduction in pCO2 in pregnancy. This change, however, does not result in a corresponding significant reduction in maternal arterial pH, because of adequate buffering. Very small changes in pH may cause significant derangement in fetal function and outcome.

  1. Polyunsaturated Fatty Acid Composition of Maternal Diet and Erythrocyte Phospholipid Status in Chilean Pregnant Women

    PubMed Central

    Bascuñán, Karla A.; Valenzuela, Rodrigo; Chamorro, Rodrigo; Valencia, Alejandra; Barrera, Cynthia; Puigrredon, Claudia; Sandoval, Jorge; Valenzuela, Alfonso

    2014-01-01

    Chilean diets are characterized by a low supply of n-3 polyunsaturated fatty acids (n-3 PUFA), which are critical nutrients during pregnancy and lactation, because of their role in brain and visual development. DHA is the most relevant n-3 PUFA in this period. We evaluated the dietary n-3 PUFA intake and erythrocyte phospholipids n-3 PUFA in Chilean pregnant women. Eighty healthy pregnant women (20–36 years old) in the 3rd–6th month of pregnancy were included in the study. Dietary assessment was done applying a food frequency questionnaire, and data were analyzed through the Food Processor SQL® software. Fatty acids of erythrocyte phospholipids were assessed by gas-liquid chromatography. Diet composition was high in saturated fat, low in mono- and PUFA, high in n-6 PUFA (linoleic acid) and low in n-3 PUFA (alpha-linolenic acid and DHA), with imbalance in the n-6/n-3 PUFA ratio. Similar results were observed for fatty acids from erythrocyte phospholipids. The sample of Chilean pregnant women showed high consumption of saturated fat and low consumption of n-3 PUFA, which is reflected in the low DHA content of erythrocyte phospholipids. Imbalance between n-6/n-3 PUFA could negatively affect fetal development. New strategies are necessary to improve n-3 PUFA intake throughout pregnancy and breast feeding periods. Furthermore, it is necessary to develop dietary interventions to improve the quality of consumed foods with particular emphasis on n-3 PUFA. PMID:25386693

  2. A knowledge-based flight status monitor for real-time application in digital avionics systems

    NASA Technical Reports Server (NTRS)

    Duke, E. L.; Disbrow, J. D.; Butler, G. F.

    1989-01-01

    The Dryden Flight Research Facility of the National Aeronautics and Space Administration (NASA) Ames Research Center (Ames-Dryden) is the principal NASA facility for the flight testing and evaluation of new and complex avionics systems. To aid in the interpretation of system health and status data, a knowledge-based flight status monitor was designed. The monitor was designed to use fault indicators from the onboard system which are telemetered to the ground and processed by a rule-based model of the aircraft failure management system to give timely advice and recommendations in the mission control room. One of the important constraints on the flight status monitor is the need to operate in real time, and to pursue this aspect, a joint research activity between NASA Ames-Dryden and the Royal Aerospace Establishment (RAE) on real-time knowledge-based systems was established. Under this agreement, the original LISP knowledge base for the flight status monitor was reimplemented using the intelligent knowledge-based system toolkit, MUSE, which was developed under RAE sponsorship. Details of the flight status monitor and the MUSE implementation are presented.

  3. Redox balance influences differentiation status of neuroblastoma in the presence of all-trans retinoic acid

    PubMed Central

    Silvis, Anne M.; McCormick, Michael L.; Spitz, Douglas R.; Kiningham, Kinsley K.

    2015-01-01

    Neuroblastoma is the most common extra-cranial solid tumor in childhood; and patients in stage IV of the disease have a high propensity for tumor recurrence. Retinoid therapy has been utilized as a means to induce differentiation of tumor cells and to inhibit relapse. In this study, the expression of a common neuronal differentiation marker [neurofilament M (NF-M)] in human SK-N-SH neuroblastoma cells treated with 10 μM all-trans retinoic acid (ATRA) showed significantly increased expression in accordance with reduced cell number. This was accompanied by an increase in MitoSOX and DCFH2 oxidation that could be indicative of increased steady-state levels of reactive oxygen species (ROS) such as O2•− and H2O2, which correlated with increased levels of MnSOD activity and immuno-reactive protein. Furthermore PEG-catalase inhibited the DCFH2 oxidation signal to a greater extent in the ATRA-treated cells (relative to controls) at 96 h indicating that as the cells became more differentiated, steady-state levels of H2O2 increased in the absence of increases in peroxide-scavenging antioxidants (i.e., glutathione, glutathione peroxidase, and catalase). In addition, ATRA-induced stimulation of NF-M at 48 and 72 h was enhanced by decreasing SOD activity using siRNA directed at MnSOD. Finally, treatment with ATRA for 96 h in the presence of MnSOD siRNA or PEG-catalase inhibited ATRA induced increases in NF-M expression. These results provide strong support for the hypothesis that changes in steady-state levels of O2•− and H2O2 significantly contribute to the process of ATRA-induced differentiation in neuroblastoma, and suggest that retinoid therapy for neuroblastoma could potentially be enhanced by redox-based manipulations of superoxide metabolism to improve patient outcome. PMID:26678800

  4. Adolescent Socioeconomic and School-Based Social Status, Smoking, and Drinking

    PubMed Central

    Sweeting, Helen; Hunt, Kate

    2015-01-01

    Purpose Relationships between subjective social status (SSS) and health-risk behaviors have received less attention than those between SSS and health. Inconsistent associations between school-based SSS and smoking or drinking might be because it is a single measure reflecting several status dimensions. We investigated how adolescent smoking and drinking are associated with “objective” socioeconomic status (SES), subjective SES, and three dimensions of school-based SSS. Methods Scottish 13–15 years-olds (N = 2,503) completed questionnaires in school-based surveys, providing information on: “objective” SES (residential deprivation, family affluence); subjective SES (MacArthur Scale youth version); and three school-based SSS dimensions (“SSS-peer”, “SSS-scholastic” and “SSS-sports”). We examined associations between each status measure and smoking (ever and weekly) and drinking (ever and usually five or more drinks) and investigated variations according to gender and age. Results Smoking and heavier drinking were positively associated with residential deprivation; associations with family affluence and subjective SES were weak or nonexistent. Both substances were related to each school-based SSS measure, and these associations were equally strong or stronger than those with deprivation. Although SSS-peer was positively associated with both smoking and (especially heavier) drinking, SSS-scholastic and SSS-sports were negatively associated with both substances. There were no gender differences in the associations and few according to age. Conclusions Subjective school-based status has stronger associations with adolescent smoking and drinking than “objective” or subjective SES. However, different dimensions of school-based status relate to adolescent smoking and drinking in opposing directions, meaning one measure based on several dimensions might show inconsistent relationships with adolescent substance use. PMID:26095407

  5. Effects of mechanical stress or abscisic acid on growth, water status and leaf abscisic acid content of eggplant seedlings

    NASA Technical Reports Server (NTRS)

    Latimer, J. G.; Mitchell, C. A.

    1988-01-01

    Container-grown eggplant (Solanum melongena L. var esculentum Nees. 'Burpee's Black Beauty') seedlings were conditioned with brief, periodic mechanical stress or abscisic acid (ABA) in a greenhouse prior to outdoor exposure. Mechanical stress consisted of seismic (shaking) or thigmic (stem flexing) treatment. Exogenous ABA (10(-3) or 10(-4)M) was applied as a soil drench 3 days prior to outdoor transfer. During conditioning, only thigmic stress reduced stem elongation and only 10(-3) M ABA reduced relative growth rate (RGR). Both conditioning treatments increased leaf specific chlorophyll content, but mechanical stress did not affect leaf ABA content. Outdoor exposure of unconditioned eggplant seedlings decreased RGR and leaf-specific chlorophyll content, but tended to increase leaf ABA content relative to that of plants maintained in the greenhouse. Conditioning did not affect RGR of plants subsequently transferred outdoors, but did reduce stem growth. Seismic stress applied in the greenhouse reduced dry weight gain by plants subsequently transferred outdoors. Mechanical stress treatments increased leaf water potential by 18-25% relative to that of untreated plants.

  6. Acid-Base Titration of (S)-Aspartic Acid: A Circular Dichroism Spectrophotometry Experiment

    NASA Astrophysics Data System (ADS)

    Cavaleiro, Ana M. V.; Pedrosa de Jesus, Júlio D.

    2000-09-01

    The magnitude of the circular dichroism of (S)-aspartic acid in aqueous solutions at a fixed wavelength varies with the addition of strong base. This laboratory experiment consists of the circular dichroism spectrophotometric acid-base titration of (S)-aspartic acid in dilute aqueous solutions, and the use of the resulting data to determine the ionization constant of the protonated amino group. The work familiarizes students with circular dichroism and illustrates the possibility of performing titrations using a less usual instrumental method of following the course of a reaction. It shows the use of a chiroptical property in the determination of the concentration in solution of an optically active molecule, and exemplifies the use of a spectrophotometric titration in the determination of an ionization constant.

  7. Relativistic effects on acidities and basicities of Brønsted acids and bases containing gold.

    PubMed

    Koppel, Ilmar A; Burk, Peeter; Kasemets, Kalev; Koppel, Ivar

    2013-11-01

    It is usually believed that relativistic effects as described by the Dirac-Schrödinger equation (relative to the classical or time-independent Schrödinger equation) are of little importance in chemistry. A closer look, however, reveals that some important and widely known properties (e.g., gold is yellow, mercury is liquid at room temperature) stem from relativistic effects. So far the influence of relativistic effects on the acid-base properties has been mostly ignored. Here we show that at least for compounds of gold such omission is completely erroneous and would lead to too high basicity and too low acidity values with errors in the range of 25-55 kcal mol(-1) (or 20 to 44 powers of ten in pK(a) units) in the gas-phase. These findings have important implications for the design of new superstrong acids and bases, and for the understanding of gold-catalysed reactions.

  8. Profiles of serum amino acids to screen for catabolic and inflammation status in calves with Mycoplasma bronchopneumonia

    PubMed Central

    TSUKANO, Kenji; SUZUKI, Kazuyuki; SHIMAMORI, Toshio; SATO, Ayano; KUDO, Katsunori; ASANO, Ryuji; AJITO, Tadaharu; LAKRITZ, Jeffrey

    2014-01-01

    The aim of the present study was to investigate the relationships between serum amino acid profiles in normal and calves with Mycoplasma bronchopneumonia. Serum free amino acid concentrations in serum obtained from 34 calves with or without Mycoplasma bronchopneumonia were determined by high-performance liquid chromatography. The calves with Mycoplasma were characterized by significantly lower total amino acid and total essential amino acid concentrations and molar ratios of branched-chain amino acid (BCAA) to aromatic amino acid (BCAA/AAA) and BCAA to tyrosine (BTR), and by a significantly higher molar ratio of serine phosphorylation (SPR). The proposed diagnostic cutoffs for BCAA/AAA, BTR and SPR in serum based on ROC analysis for detection of catabolic states associated with Mycoplasma bronchopneumonia were set at <1.75, <2.86 and >0.85, respectively. Our results suggest that determining the profiles of amino acids, especially BTR and SPR, could provide useful diagnostic information in terms of predicting protein catabolism in Mycoplasma bronchopneumonia. PMID:25342635

  9. Nucleic acid-based nanoengineering: novel structures for biomedical applications

    PubMed Central

    Li, Hanying; LaBean, Thomas H.; Leong, Kam W.

    2011-01-01

    Nanoengineering exploits the interactions of materials at the nanometre scale to create functional nanostructures. It relies on the precise organization of nanomaterials to achieve unique functionality. There are no interactions more elegant than those governing nucleic acids via Watson–Crick base-pairing rules. The infinite combinations of DNA/RNA base pairs and their remarkable molecular recognition capability can give rise to interesting nanostructures that are only limited by our imagination. Over the past years, creative assembly of nucleic acids has fashioned a plethora of two-dimensional and three-dimensional nanostructures with precisely controlled size, shape and spatial functionalization. These nanostructures have been precisely patterned with molecules, proteins and gold nanoparticles for the observation of chemical reactions at the single molecule level, activation of enzymatic cascade and novel modality of photonic detection, respectively. Recently, they have also been engineered to encapsulate and release bioactive agents in a stimulus-responsive manner for therapeutic applications. The future of nucleic acid-based nanoengineering is bright and exciting. In this review, we will discuss the strategies to control the assembly of nucleic acids and highlight the recent efforts to build functional nucleic acid nanodevices for nanomedicine. PMID:23050076

  10. Crystal and molecular structure of eight organic acid-base adducts from 2-methylquinoline and different acids

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Jin, Shouwen; Tao, Lin; Liu, Bin; Wang, Daqi

    2014-08-01

    Eight supramolecular complexes with 2-methylquinoline and acidic components as 4-aminobenzoic acid, 2-aminobenzoic acid, salicylic acid, 5-chlorosalicylic acid, 3,5-dinitrosalicylic acid, malic acid, sebacic acid, and 1,5-naphthalenedisulfonic acid were synthesized and characterized by X-ray crystallography, IR, mp, and elemental analysis. All of the complexes are organic salts except compound 2. All supramolecular architectures of 1-8 involve extensive classical hydrogen bonds as well as other noncovalent interactions. The results presented herein indicate that the strength and directionality of the classical hydrogen bonds (ionic or neutral) between acidic components and 2-methylquinoline are sufficient to bring about the formation of binary organic acid-base adducts. The role of weak and strong noncovalent interactions in the crystal packing is ascertained. These weak interactions combined, the complexes 1-8 displayed 2D-3D framework structure.

  11. Status of the Linac based positron source at Saclay

    NASA Astrophysics Data System (ADS)

    Rey, J.-M.; Coulloux, G.; Debu, P.; Dzitko, H.; Hardy, P.; Liszkay, L.; Lotrus, P.; Muranaka, T.; Noel, C.; Pérez, P.; Pierret, O.; Ruiz, N.; Sacquin, Y.

    2013-06-01

    Low energy positron beams are of major interest for fundamental science and materials science. IRFU has developed and built a slow positron source based on a compact, low energy (4.3 MeV) electron linac. The linac-based source will provide positrons for a magnetic storage trap and represents the first step of the GBAR experiment (Gravitational Behavior of Antimatter in Rest) recently approved by CERN for an installation in the Antiproton Decelerator hall. The installation built in Saclay will be described with its main characteristics. The ultimate target of the GBAR experiment will be briefly presented as well as the foreseen development of an industrial positron source dedicated for materials science laboratories.

  12. Technology Status of HNF-based Monopropellants for Satellite Propulsion

    NASA Astrophysics Data System (ADS)

    Marée, A. G. M.; Moerel, J.-L.; Welland-Veltmans, W.; Wierckx, F.; Zevenbergen, J.

    2004-10-01

    This paper reports on significant technological progress made over the last few years in determining the feasibility of HNF-based monopropellants. An HNF- based monopropellant is an interesting alternative for hydrazine as monopropellant for satellite propulsion. New non-toxic monopropellants based on dissolved energetic oxidizer salts (e.g. HNF, HAN and ADN) have better performance, lower toxicity and higher storage density than hydrazine. New HNF-monopropellant blends will be presented which have a 5% and 10% higher performance than hydrazine at minimum storage temperatures of 0 and 10 degrees Celsius respectively. This is a major improvement compared with earlier HNF monopropellant blends with a performance equal to hydrazine which must be stored at a minimum temperature of 20 degrees Celsius. Furthermore, these blends are characterized by very low vapour pressures, which is beneficial for two reasons: very low risk of inhalation of harmful vapours and in case of spillage during handling or transport there will be a very low risk of crystallization of solid HNF-crystals. These new blends will be submitted to an extensive characterization program this year. This will include determination of physical properties (e.g. density and viscosity), explosion sensitivity and compatibility with common materials of satellite propulsion systems. Also catalytic ignition and production methods will be demonstrated this year.

  13. Status of fatty acids as skin penetration enhancers-a review.

    PubMed

    Mittal, Ashu; Sara, U V S; Ali, Asgar; Aqil, Mohd

    2009-07-01

    Novel techniques for drug delivery have been investigated in human medicine in recent years. The transdermal route of drug delivery has attracted researchers due to many biomedical advantages associated with it. However, excellent impervious nature of skin is the greatest challenge that has to be overcome for successfully delivering drug molecules to the systemic circulation by this route. One long-standing approach for improving transdermal drug delivery uses penetration enhancers (also called sorption promoters or accelerants) that can reversibly compromise the skin's barrier function and consequently allow the entry of otherwise poorly penetrating molecules into the membrane and through to the systemic circulation. A large number of fatty acids have been used as permeation enhancers. They have proven to be effective and safe sorption promoters. This present review includes the classification, feasibility and application of fatty acids as sorption promoters for improved delivery of drug through skin. PMID:19604141

  14. Acid-base metabolism: implications for kidney stones formation.

    PubMed

    Hess, Bernhard

    2006-04-01

    The physiology and pathophysiology of renal H+ ion excretion and urinary buffer systems are reviewed. The main focus is on the two major conditions related to acid-base metabolism that cause kidney stone formation, i.e., distal renal tubular acidosis (dRTA) and abnormally low urine pH with subsequent uric acid stone formation. Both the entities can be seen on the background of disturbances of the major urinary buffer system, NH3+ <--> NH4+. On the one hand, reduced distal tubular secretion of H+ ions results in an abnormally high urinary pH and either incomplete or complete dRTA. On the other hand, reduced production/availability of NH4+ is the cause of an abnormally low urinary pH, which predisposes to uric acid stone formation. Most recent research indicates that the latter abnormality may be a renal manifestation of the increasingly prevalent metabolic syndrome. Despite opposite deviations from normal urinary pH values, both the dRTA and uric acid stone formation due to low urinary pH require the same treatment, i.e., alkali. In the dRTA, alkali is needed for improving the body's buffer capacity, whereas the goal of alkali treatment in uric acid stone formers is to increase the urinary pH to 6.2-6.8 in order to minimize uric acid crystallization.

  15. Acid/base account and minesoils: A review

    SciTech Connect

    Hossner, L.R.; Brandt, J.E.

    1997-12-31

    Generation of acidity from the oxidation of iron sulfides (FeS{sub 2}) is a common feature of geological materials exposed to the atmosphere by mining activities. Acid/base accounting (ABA) has been the primary method to evaluate the acid- or alkaline-potential of geological materials and to predict if weathering of these materials will have an adverse effect on terrestrial and aquatic environments. The ABA procedure has also been used to evaluate minesoils at different stages of weathering and, in some cases, to estimate lime requirements. Conflicting assessments of the methodology have been reported in the literature. The ABA is the fastest and easiest way to evaluate the acid-forming characteristics of overburden materials; however, accurate evaluations sometimes require that ABA data be examined in conjunction with additional sample information and results from other analytical procedures. The end use of ABA data, whether it be for minesoil evaluation or water quality prediction, will dictate the method`s interpretive criteria. Reaction kinetics and stoichiometry may vary and are not clearly defined for all situations. There is an increasing awareness of the potential for interfering compounds, particularly siderite (FeCO{sub 3}), to be present in geological materials associated with coal mines. Hardrock mines, with possible mixed sulfide mineralogy, offer a challenge to the ABA, since acid generation may be caused by minerals other than pyrite. A combination of methods, static and kinetic, is appropriate to properly evaluate the presence of acid-forming materials.

  16. Rapid adjustment of guard-cell abscisic acid levels to current leaf-water status

    SciTech Connect

    Harris, M.J.; Outlaw, W.H. Jr. )

    1991-01-01

    Detached broad bean (Vicia faba L.) leaflets were water stressed; within 15 minutes, guard-cell abscisic acid (ABA) concentration increased ninefold. This result eliminates the apparent discrepancy raised by reports of no correlation between initial water-stress effects on stomata and leaf ABA concentration. Six hours after stress relief, guard-cell ABA concentration was near the prestress value, which would seem to implicate other factors in stress after-effects on stomata.

  17. Adolescent socio-economic and school-based social status, health and well-being

    PubMed Central

    Sweeting, Helen; Hunt, Kate

    2014-01-01

    Studies of adults and adolescents suggest subjective socio-economic status (SES) is associated with health/well-being even after adjustment for objective SES. In adolescence, objective SES may have weaker relationships with health/well-being than at other life stages; school-based social status may be of greater relevance. We investigated the associations which objective SES (residential deprivation and family affluence), subjective SES and three school-based subjective social status dimensions (“SSS-peer”, “SSS-scholastic” and “SSS-sports”) had with physical symptoms, psychological distress and anger among 2503 Scottish 13–15 year-olds. Associations between objective SES and health/well-being were weak and inconsistent. Lower subjective SES was associated with increased physical symptoms and psychological distress, lower SSS-peer with increased psychological distress but reduced anger, lower SSS-scholastic with increased physical symptoms, psychological distress and anger, and lower SSS-sports with increased physical symptoms and psychological distress. Associations did not differ by gender. Objective and subjective SES had weaker associations with health/well-being than did school-based SSS dimensions. These findings underline the importance of school-based SSS in adolescence, and the need for future studies to include a range of school-based SSS dimensions and several health/well-being measures. They also highlight the need for a focus on school-based social status among those working to promote adolescent health/well-being. PMID:25306408

  18. Students' Understanding of Acids/Bases in Organic Chemistry Contexts

    ERIC Educational Resources Information Center

    Cartrette, David P.; Mayo, Provi M.

    2011-01-01

    Understanding key foundational principles is vital to learning chemistry across different contexts. One such foundational principle is the acid/base behavior of molecules. In the general chemistry sequence, the Bronsted-Lowry theory is stressed, because it lends itself well to studying equilibrium and kinetics. However, the Lewis theory of…

  19. Turkish Prospective Chemistry Teachers' Alternative Conceptions about Acids and Bases

    ERIC Educational Resources Information Center

    Boz, Yezdan

    2009-01-01

    The purpose of this study was to obtain prospective chemistry teachers' conceptions about acids and bases concepts. Thirty-eight prospective chemistry teachers were the participants. Data were collected by means of an open-ended questionnaire and semi-structured interviews. Analysis of data indicated that most prospective teachers did not have…

  20. Thymine, adenine and lipoamino acid based gene delivery systems.

    PubMed

    Skwarczynski, Mariusz; Ziora, Zyta M; Coles, Daniel J; Lin, I-Chun; Toth, Istvan

    2010-05-14

    A novel class of thymine, adenine and lipoamino acid based non-viral carriers for gene delivery has been developed. Their ability to bind to DNA by hydrogen bonding was confirmed by NMR diffusion, isothermal titration calorimetry and transmission electron microscopy experiments.

  1. Photoresponsive self-assemblies based on fatty acids.

    PubMed

    Fameau, A-L; Arnould, A; Lehmann, M; von Klitzing, R

    2015-02-18

    Photoresponsive surfactant system based on fatty acids has been developed by the introduction in aqueous solution of a photoacid generator (PAG). Self-assembly transitions are triggered by UV irradiation due to a pH change induced by the presence of PAG.

  2. Acid-Base Disorders--A Computer Simulation.

    ERIC Educational Resources Information Center

    Maude, David L.

    1985-01-01

    Describes and lists a program for Apple Pascal Version 1.1 which investigates the behavior of the bicarbonate-carbon dioxide buffer system in acid-base disorders. Designed specifically for the preclinical medical student, the program has proven easy to use and enables students to use blood gas parameters to arrive at diagnoses. (DH)

  3. A Schiff base formed from sulfanilic acid and dimethylformamide.

    PubMed

    Hempel, A; Camerman, N; Mastropaolo, D; Camerman, A

    1999-04-15

    The crystal structure the Schiff base contains one 4-dimethylaminomethyleneaminobenzenesulfonic acid molecule in zwitterionic form [4-(dimethylaminomethyleneammonio)benzenesulfonate], and one water molecule in the asymmetric unit (C9H12N2O3S.H2O). Protonation occurs at nitrogen atom N1, but the charge is delocalized.

  4. Using Spreadsheets to Produce Acid-Base Titration Curves.

    ERIC Educational Resources Information Center

    Cawley, Martin James; Parkinson, John

    1995-01-01

    Describes two spreadsheets for producing acid-base titration curves, one uses relatively simple cell formulae that can be written into the spreadsheet by inexperienced students and the second uses more complex formulae that are best written by the teacher. (JRH)

  5. Regulation of mTORC1 by growth factors, energy status, amino acids and mechanical stimuli at a glance.

    PubMed

    Bond, Peter

    2016-01-01

    The mechanistic/mammalian target of rapamycin complex 1 (mTORC1) plays a pivotal role in the regulation of skeletal muscle protein synthesis. Activation of the complex leads to phosphorylation of two important sets of substrates, namely eIF4E binding proteins and ribosomal S6 kinases. Phosphorylation of these substrates then leads to an increase in protein synthesis, mainly by enhancing translation initiation. mTORC1 activity is regulated by several inputs, such as growth factors, energy status, amino acids and mechanical stimuli. Research in this field is rapidly evolving and unraveling how these inputs regulate the complex. Therefore this review attempts to provide a brief and up-to-date narrative on the regulation of this marvelous protein complex. Additionally, some sports supplements which have been shown to regulate mTORC1 activity are discussed. PMID:26937223

  6. Ferulic Acid modulates altered lipid profiles and prooxidant/antioxidant status in circulation during nicotine-induced toxicity: a dose-dependent study.

    PubMed

    Sudheer, Adluri Ram; Chandran, Kalpana; Marimuthu, Srinivasan; Menon, Venugopal Padmanabhan

    2005-01-01

    Nicotine, an active ingredient of tobacco smoke, is known to induce hyperlipidemia and disturb the prooxidant-antioxidant status. In our study, ferulic acid, a naturally occurring nutritional compound, was tested for its antioxidant and antihyperlipidemic property in a dose-dependent manner against nicotine-induced toxicity in female Wistar rats. We tested three different doses of ferulic acid-10 mg, 20 mg, and 40 mg/kg body weight-for their protective effects. The activities of biochemical marker enzymes lactate dehydrogenase and alkaline phosphatase, levels of peroxidative indices (thiobarbituric acid reactive substances and hydroperoxides), nitric oxide, and circulatory lipids (cholesterol, triglycerides, free fatty acids, and phospholipids) were increased significantly in the nicotine-treated group when compared to normal, which were brought down in ferulic acid-treated groups. The antioxidant status (superoxide dismutase, catalase, glutathione peroxidase, vitamin E, and reduced glutathione) was found to be decreased in the nicotine-treated group, and was significantly increased in ferulic acid-administered groups. Further, ferulic acid also positively modulated the nicotine-induced changes in the micronutrients (zinc and copper) level. The dose 20 mg/kg body weight was found to be more effective than the other two doses. Our data suggest that FA exerts its preventive effects by modulating the degree of lipid peroxidation, antioxidant status, lipid profiles, and trace element levels during nicotine-induced toxicity. PMID:20021059

  7. Mechanisms of Acid and Base Secretion by the Airway Epithelium

    PubMed Central

    Fischer, Horst; Widdicombe, Jonathan H.

    2010-01-01

    SUMMARY One of the main functions of the airway epithelium is to inactivate and remove infectious particles from inhaled air and thereby prevent infection of the distal lung. This function is achieved by mucociliary and cough clearance and by antimicrobial factors present in the airway surface liquid (ASL). There are indications that airway defenses are affected by the pH of the ASL and historically, acidification of the airway surfaces has been suggested as a measure of airway disease. However, even in health, the ASL is slightly acidic, and this acidity might be part of normal airway defense. Only recently research has focused on the mechanisms responsible for acid and base secretion into the ASL. Advances resulted from research into the airway disease associated with cystic fibrosis (CF) after it was found that the CFTR C1- channel conducts HCO3- and, therefore, may contribute to ASL pH. However, the acidity of the ASL indicated parallel mechanisms for H+ secretion. Recent investigations identified several H+ transporters in the apical membrane of the airway epithelium. These include H+ channels and ATP-driven H+ pumps, including a non-gastric isoform of the H+-K+ ATPase and a vacuolar-type H+ ATPase. Current knowledge of acid and base transporters and their potential roles in airway mucosal pH regulation is reviewed here. PMID:17091214

  8. Combination therapy with zoledronic acid and cetuximab effectively suppresses growth of colorectal cancer cells regardless of KRAS status

    PubMed Central

    Kato, Junko; Kanematsu, Masako; Gaowa, Siqin; Mori, Ryutaro; Tanahashi, Toshiyuki; Matsuhashi, Nobuhisa; Yoshida, Kazuhiro

    2016-01-01

    Targeted molecular therapy is an effective anticancer strategy. Anti‐EGFR monoclonal antibodies such as cetuximab (CTX) have been approved for the treatment of various malignancies, including colorectal cancer (CRC) with wild‐type KRAS. However, their efficacy in patients with KRAS mutations has not been established. Therefore, we investigated whether CTX treatment was effective as a single agent or in combination with zoledronic acid (ZOL) in human CRC cell lines with different KRAS status. CRC cell lines SW48 (wild‐type KRAS) and LS174T (mutant KRAS) were treated with ZOL, CTX and a combination of both drugs. Cytotoxicity was measured using the MTT assay. Changes in the levels of intracellular signaling proteins were evaluated using western blot analysis. Finally, we evaluated the efficacy of the combination treatment in an in vivo xenograft model. We observed that ZOL apparently inhibited growth in both cell lines, whereas CTX showed little effect. ZOL also increased the levels of unprenylated RAS. Combined ZOL and CTX treatment was synergistic in both cell lines and was associated with inhibition of the RAS‐MAPK and AKT‐mTOR signaling pathways. Furthermore, the combination treatment was more effective in suppressing the growth of xenografts derived from both SW48 and LS174T cells; this effect was associated with increased apoptosis. These results demonstrate that ZOL inhibits the growth of colon cancer cells regardless of KRAS status, and combination therapy using ZOL and CTX enhances this growth suppression. These findings suggest a novel strategy for the treatment of CRC independent of KRAS mutational status. PMID:26437179

  9. Effect of dietary folic acid supplementation on egg folate content and the performance and folate status of two strains of laying hens.

    PubMed

    Hebert, K; House, J D; Guenter, W

    2005-10-01

    Enrichment of eggs with folate is possible when dietary folic acid levels are increased. However, development of optimal strategies for the production of folate-enriched eggs requires knowledge as to differences due to strain of bird and a greater understanding of the factors limiting egg folate deposition. To this end, a study was designed to determine the response of two leghorn strains that differ in production performance. Hyline W36 and W98 hens (n = 6 per diet) received a barley-based ration containing 0, 2, 4, 8, 16, 32, 64, or 128 mg/kg of crystalline folic acid for 21 d. Response criteria included production parameters, measures of blood folate status, and egg folate content. Significant (P < 0.05) main effects of folate supplementation were observed for egg folate content and plasma folate, which increased, and homocysteine concentrations, which decreased with supplementation; performance, however, was not affected. The Hyline W98 strain had significantly (P < 0.05) higher total egg and yolk weights and feed consumption when compared with the W36. Significant (P < 0.05) ration x strain interactions were observed for egg and yolk weight, egg folate content, and plasma homocysteine. The higher egg mass producing strain, Hyline W98, benefited from increased folic acid through a reduction in plasma homocysteine concentrations, suggesting that this strain has a higher requirement for folate than the W36 strain. Overall, egg folate content is maximized when crystalline folic acid is supplemented to the diet at 2 mg/kg or higher. Higher levels of egg folate are not achieved due to the saturation of the precursor pool for egg folate deposition.

  10. The effect of humic acids and their complexes with iron on the functional status of plants grown under iron deficiency

    NASA Astrophysics Data System (ADS)

    Abros'kin, D. P.; Fuentes, M.; Garcia-Mina, J. M.; Klyain, O. I.; Senik, S. V.; Volkov, D. S.; Perminova, I. V.; Kulikova, N. A.

    2016-10-01

    The effect of humic acids (HAs) and their iron complexes (Fe-HAs) on the input of the main mineral elements into wheat seedlings, as well as on the efficiency of photosynthesis and the lipid profile of plants, under iron deficiency has been studied. The input of iron from Fe-HA complexes and its predominant accumulation in roots are demonstrated. It is found that HAs increase the efficiency of photosynthesis due to enhanced electron transport in photosystem II. It is shown that the application of HAs and Fe-HAs is accompanied by an enhanced input of Zn into plants, which could increase the antioxidant status of plants under iron deficiency conditions. In addition, a pronounced increase in the content of lipids in plants is revealed, which is indicative of the effect of HAs on plant metabolism. The obtained results suggest that the positive effect of Fe-HAs and HAs on plants under iron deficiency conditions is due to a combination of factors, among which the effect of HAs on the antioxidant status of plants and the plant lipid metabolism predominates.

  11. Risk-based decisionmaking in the DOE: Challenges and status

    SciTech Connect

    Henry, C.J.; Alchowiak, J.; Moses, M.

    1995-12-31

    The primary mission of the Environmental Management Program is to protect human health and the environment, the first goal of which must be, to address urgent risks and threats. Another is to provide for a safe workplace. Without credible risk assessments and good risk management practices, the central environmental goals cannot be met. Principles for risk analysis which include principles for risk assessment, management, communication, and priority setting were adopted. As recommended, Environmental Management is using risk-based decision making in its budget process and in the implementation of its program. The challenges presented in using a risk-based Decision making process are to integrate risk assessment methods and cultural and social values so as to produce meaningful priorities. The different laws and regulations governing the Department define risk differently in implementing activities to protect human health and the environment, therefore, assumptions and judgements in risk analysis vary. Currently, the Environmental Management Program is developing and improving a framework to incorporate risk into the budget process and to link the budget, compliance requirements and risk reduction/pollution prevention activities.

  12. Primordial transport of sugars and amino acids via Schiff bases

    NASA Astrophysics Data System (ADS)

    Stillwell, William; Rau, Aruna

    1981-09-01

    Experimental support is given for a model concerning the origin of a primordial transport system. The model is based on the facilitated diffusion of amino acids stimulated by aliphatic aldehyde carriers and sugars stimulated by aliphatic amine carriers. The lipid-soluble diffusing species is the Schiff base. The possible role of this simple transport system in the origin of an early protocell is discussed.

  13. The Case of Web-Based Course on Taxation: Current Status, Problems and Future Improvement

    NASA Astrophysics Data System (ADS)

    Qin, Zhigang

    This paper mainly introduces the case of the web-based course on taxation developed by Xiamen University. We analyze the current status, problems and future improvement of the web-based course. The web-based course has the basic contents and modules, but it has several problems including unclear object, lacking interaction, lacking examination module, lacking study management module, and the learning materials and the navigation are too simple. According to its problems, we put forward the measures to improve it.

  14. A simplified strong ion model for acid-base equilibria: application to horse plasma.

    PubMed

    Constable, P D

    1997-07-01

    The Henderson-Hasselbalch equation and Stewart's strong ion model are currently used to describe mammalian acid-base equilibria. Anomalies exist when the Henderson-Hasselbalch equation is applied to plasma, whereas the strong ion model does not provide a practical method for determining the total plasma concentration of nonvolatile weak acids ([Atot]) and the effective dissociation constant for plasma weak acids (Ka). A simplified strong ion model, which was developed from the assumption that plasma ions act as strong ions, volatile buffer ions (HCO-3), or nonvolatile buffer ions, indicates that plasma pH is determined by five independent variables: PCO2, strong ion difference, concentration of individual nonvolatile plasma buffers (albumin, globulin, and phosphate), ionic strength, and temperature. The simplified strong ion model conveys on a fundamental level the mechanism for change in acid-base status, explains many of the anomalies when the Henderson-Hasselbalch equation is applied to plasma, is conceptually and algebraically simpler than Stewart's strong ion model, and provides a practical in vitro method for determining [Atot] and Ka of plasma. Application of the simplified strong ion model to CO2-tonometered horse plasma produced values for [Atot] (15.0 +/- 3.1 meq/l) and Ka (2.22 +/- 0.32 x 10(-7) eq/l) that were significantly different from the values commonly assumed for human plasma ([Atot] = 20.0 meq/l, Ka = 3.0 x 10(-7) eq/l). Moreover, application of the experimentally determined values for [Atot] and Ka to published data for the horse (known PCO2, strong ion difference, and plasma protein concentration) predicted plasma pH more accurately than the values for [Atot] and Ka commonly assumed for human plasma. Species-specific values for [Atot] and Ka should be experimentally determined when the simplified strong ion model (or strong ion model) is used to describe acid-base equilibria.

  15. Model for acid-base chemistry in nanoparticle growth (MABNAG)

    NASA Astrophysics Data System (ADS)

    Yli-Juuti, T.; Barsanti, K.; Hildebrandt Ruiz, L.; Kieloaho, A.-J.; Makkonen, U.; Petäjä, T.; Ruuskanen, T.; Kulmala, M.; Riipinen, I.

    2013-03-01

    Climatic effects of newly-formed atmospheric secondary aerosol particles are to a large extent determined by their condensational growth rates. However, all the vapors condensing on atmospheric nanoparticles and growing them to climatically relevant sizes are not identified yet and the effects of particle phase processes on particle growth rates are poorly known. Besides sulfuric acid, organic compounds are known to contribute significantly to atmospheric nanoparticle growth. In this study a particle growth model MABNAG (Model for Acid-Base chemistry in NAnoparticle Growth) was developed to study the effect of salt formation on nanoparticle growth, which has been proposed as a potential mechanism lowering the equilibrium vapor pressures of organic compounds through dissociation in the particle phase and thus preventing their evaporation. MABNAG is a model for monodisperse aqueous particles and it couples dynamics of condensation to particle phase chemistry. Non-zero equilibrium vapor pressures, with both size and composition dependence, are considered for condensation. The model was applied for atmospherically relevant systems with sulfuric acid, one organic acid, ammonia, one amine and water in the gas phase allowed to condense on 3-20 nm particles. The effect of dissociation of the organic acid was found to be small under ambient conditions typical for a boreal forest site, but considerable for base-rich environments (gas phase concentrations of about 1010 cm-3 for the sum of the bases). The contribution of the bases to particle mass decreased as particle size increased, except at very high gas phase concentrations of the bases. The relative importance of amine versus ammonia did not change significantly as a function of particle size. While our results give a reasonable first estimate on the maximum contribution of salt formation to nanoparticle growth, further studies on, e.g. the thermodynamic properties of the atmospheric organics, concentrations of low

  16. An explanation of flocculation using Lewis acid-base theory

    SciTech Connect

    Brown, P.M.; Stanley, D.A.; Scheiner, B.J.

    1988-01-01

    This paper describes a Bureau of Mines-devleoped method of dewatering clay slurries based on flocculation by high-molecular-weight polymers and water removal from the formed flocs using a trommel or hydrosieve. The exchange ion on the clays affects their dewaterability. Metal ions in solution and on the exchange sites of smectite clays are known to act as Lewis acids. Recent work has determined that these ions can be titrated with high-molecular-weight polymers. The relative acidity of the exchange ion and the basicity of the polymer determined by the new method give insight into the dewatering mechanism.

  17. Genetic and epigenetic transgenerational implications related to omega-3 fatty acids. Part I: maternal FADS2 genotype and DNA methylation correlate with polyunsaturated fatty acid status in toddlers: an exploratory analysis.

    PubMed

    Lupu, Daniel S; Cheatham, Carol L; Corbin, Karen D; Niculescu, Mihai D

    2015-11-01

    Polyunsaturated fatty acid metabolism in toddlers is regulated by a complex network of interacting factors. The contribution of maternal genetic and epigenetic makeup to this milieu is not well understood. In a cohort of mothers and toddlers 16 months of age (n = 65 mother-child pairs), we investigated the association between maternal genetic and epigenetic fatty acid desaturase 2 (FADS2) profiles and toddlers' n-6 and n-3 fatty acid metabolism. FADS2 rs174575 variation and DNA methylation status were interrogated in mothers and toddlers, as well as food intake and plasma fatty acid concentrations in toddlers. A multivariate fit model indicated that maternal rs174575 genotype, combined with DNA methylation, can predict α-linolenic acid plasma concentration in all toddlers and arachidonic acid concentrations in boys. Arachidonic acid intake was predictive for its plasma concentration in girls, whereas intake of 3 major n-3 species (eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were predictive for their plasma concentrations in boys. FADS2 genotype and DNA methylation in toddlers were not related to plasma concentrations or food intakes, except for CpG8 methylation. Maternal FADS2 methylation was a predictor for the boys' α-linolenic acid intakes. This exploratory study suggests that maternal FADS2 genetic and epigenetic status could be related to toddlers' polyunsaturated fatty acid metabolism.

  18. Acid-base transport in pancreas—new challenges

    PubMed Central

    Novak, Ivana; Haanes, Kristian A.; Wang, Jing

    2013-01-01

    Along the gastrointestinal tract a number of epithelia contribute with acid or basic secretions in order to aid digestive processes. The stomach and pancreas are the most extreme examples of acid (H+) and base (HCO−3) transporters, respectively. Nevertheless, they share the same challenges of transporting acid and bases across epithelia and effectively regulating their intracellular pH. In this review, we will make use of comparative physiology to enlighten the cellular mechanisms of pancreatic HCO−3 and fluid secretion, which is still challenging physiologists. Some of the novel transporters to consider in pancreas are the proton pumps (H+-K+-ATPases), as well as the calcium-activated K+ and Cl− channels, such as KCa3.1 and TMEM16A/ANO1. Local regulators, such as purinergic signaling, fine-tune, and coordinate pancreatic secretion. Lastly, we speculate whether dys-regulation of acid-base transport contributes to pancreatic diseases including cystic fibrosis, pancreatitis, and cancer. PMID:24391597

  19. The phosphorylation status and cytoskeletal remodeling of striatal astrocytes treated with quinolinic acid

    SciTech Connect

    Pierozan, Paula; Ferreira, Fernanda; Ortiz de Lima, Bárbara; Gonçalves Fernandes, Carolina; Totarelli Monteforte, Priscila; Castro Medaglia, Natalia de; Bincoletto, Claudia; Soubhi Smaili, Soraya; Pessoa-Pureur, Regina

    2014-04-01

    Quinolinic acid (QUIN) is a glutamate agonist which markedly enhances the vulnerability of neural cells to excitotoxicity. QUIN is produced from the amino acid tryptophan through the kynurenine pathway (KP). Dysregulation of this pathway is associated with neurodegenerative conditions. In this study we treated striatal astrocytes in culture with QUIN and assayed the endogenous phosphorylating system associated with glial fibrillary acidic protein (GFAP) and vimentin as well as cytoskeletal remodeling. After 24 h incubation with 100 µM QUIN, cells were exposed to {sup 32}P-orthophosphate and/or protein kinase A (PKA), protein kinase dependent of Ca{sup 2+}/calmodulin II (PKCaMII) or protein kinase C (PKC) inhibitors, H89 (20 μM), KN93 (10 μM) and staurosporin (10 nM), respectively. Results showed that hyperphosphorylation was abrogated by PKA and PKC inhibitors but not by the PKCaMII inhibitor. The specific antagonists to ionotropic NMDA and non-NMDA (50 µM DL-AP5 and CNQX, respectively) glutamate receptors as well as to metabotropic glutamate receptor (mGLUR; 50 µM MCPG), mGLUR1 (100 µM MPEP) and mGLUR5 (10 µM 4C3HPG) prevented the hyperphosphorylation provoked by QUIN. Also, intra and extracellular Ca{sup 2+} quelators (1 mM EGTA; 10 µM BAPTA-AM, respectively) prevented QUIN-mediated effect, while Ca{sup 2+} influx through voltage-dependent Ca{sup 2+} channel type L (L-VDCC) (blocker: 10 µM verapamil) is not implicated in this effect. Morphological analysis showed dramatically altered actin cytoskeleton with concomitant change of morphology to fusiform and/or flattened cells with retracted cytoplasm and disruption of the GFAP meshwork, supporting misregulation of actin cytoskeleton. Both hyperphosphorylation and cytoskeletal remodeling were reversed 24 h after QUIN removal. Astrocytes are highly plastic cells and the vulnerability of astrocyte cytoskeleton may have important implications for understanding the neurotoxicity of QUIN in neurodegenerative

  20. Status of commercial phosphoric acid fuel cell power plant system development

    NASA Technical Reports Server (NTRS)

    Warshay, M.

    1987-01-01

    A technology development and commercial feasibility evaluation is presented for phosphoric acid fuel cells (PAFCs) applicable to electric utility operations. The correction of identified design deficiencies in the control card and water treatment subsystems is projected to be able to substantially increase average powerplant availability from the 63 percent achieved in recent field tests of a PAFC system. Current development work is proceeding under NASA research contracts at the output levels of a multimegawatt facility for electric utility use, a multikilowatt on-site integrated energy generation facility, and advanced electrocatalysts applicable to PAFCs.

  1. Status of PEM-based polarimetric MSE development at KSTAR

    NASA Astrophysics Data System (ADS)

    Ko, Jinseok; Chung, Jinil; Oh, Seung Tae; Ko, Won-Ha; de Bock, Maarten; Ong, Henry; Lange, Guido

    2014-10-01

    A multi-chord PEM (photo elastic modulator)-based polarimetric motional Stark effect (MSE) system is under development for the KSTAR tokamak. The conceptual design for the front optics was optimized to preserve not only the polarization state of the input light for the MSE measurements but also the signal intensity of the existing charge exchange spectroscopy (CES) system that will share the front optics with the MSE. The optics design incorporates how to determine the number of channels and the number of fibers for each channel. A dielectric coating will be applied on the mirror to minimize the relative reflectivity and the phase shift between the two orthogonal polarization components of the incident light. Lenses with low stress-birefringence constants will be adopted to minimize non-linear and random changes in the polarization through the lenses, which is a trade-off with the rather high Faraday rotation in the lenses because the latter effect is linear and can be relatively easily calibrated out. Intensive spectrum measurements and their comparisons with the simulated spectra are done to assist the design of the bandpass filter system that will also use tilting stages to remotely control the passband. Following the system installation in 2014, the MSE measurements are expected to be performed during the 2015 KSTAR campaign.

  2. 21 CFR 862.1450 - Lactic acid test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ....1450 Lactic acid test system. (a) Identification. A lactic acid test system is a device intended to measure lactic acid in whole blood and plasma. Lactic acid measurements that evaluate the acid-base status... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Lactic acid test system. 862.1450 Section...

  3. 21 CFR 862.1450 - Lactic acid test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....1450 Lactic acid test system. (a) Identification. A lactic acid test system is a device intended to measure lactic acid in whole blood and plasma. Lactic acid measurements that evaluate the acid-base status... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Lactic acid test system. 862.1450 Section...

  4. 21 CFR 862.1450 - Lactic acid test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....1450 Lactic acid test system. (a) Identification. A lactic acid test system is a device intended to measure lactic acid in whole blood and plasma. Lactic acid measurements that evaluate the acid-base status... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Lactic acid test system. 862.1450 Section...

  5. 21 CFR 862.1450 - Lactic acid test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....1450 Lactic acid test system. (a) Identification. A lactic acid test system is a device intended to measure lactic acid in whole blood and plasma. Lactic acid measurements that evaluate the acid-base status... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Lactic acid test system. 862.1450 Section...

  6. Antifouling gold surfaces grafted with aspartic acid and glutamic acid based zwitterionic polymer brushes.

    PubMed

    Li, Wenchen; Liu, Qingsheng; Liu, Lingyun

    2014-10-28

    We report two new amino acid based antifouling zwitterionic polymers, poly(N(4)-(2-methacrylamidoethyl)asparagine) (pAspAA) and poly(N(5)-(2-methacrylamidoethyl)glutamine) (pGluAA). The vinyl monomers were developed from aspartic acid and glutamic acid. Surface-initiated photoiniferter-mediated polymerization was employed to graft polymer brushes from gold surfaces. Different thickness of polymer brushes was controlled by varying UV irradiation time. The nonspecific adsorption from undiluted human blood serum and plasma was studied by surface plasmon resonance (SPR). With the polymer film as thin as 11-12 nm, the adsorption on pAspAA from serum and plasma was as low as 0.75 and 5.18 ng/cm(2), respectively, and 1.88 and 10.15 ng/cm(2), respectively, for pGluAA. The adsorption amount is comparable to or even better than other amino acid based zwitterionic polymers such as poly(serine methacrylate), poly(lysine methacrylamide), and poly(ornithine methacrylamide) and other widely used antifouling polymers such as poly(sulfobetaine methacrylate), even under thinner polymer film thickness. The pAspAA and pGluAA grafted surfaces also showed strong resistance to endothelial cell attachment. The possession of both zwitterionic structure and hydrophilic amide groups, biomimetic property, and multifunctionality make pAspAA and pGluAA promising candidates for biocompatible antifouling functionalizable materials. PMID:25262768

  7. Antifouling gold surfaces grafted with aspartic acid and glutamic acid based zwitterionic polymer brushes.

    PubMed

    Li, Wenchen; Liu, Qingsheng; Liu, Lingyun

    2014-10-28

    We report two new amino acid based antifouling zwitterionic polymers, poly(N(4)-(2-methacrylamidoethyl)asparagine) (pAspAA) and poly(N(5)-(2-methacrylamidoethyl)glutamine) (pGluAA). The vinyl monomers were developed from aspartic acid and glutamic acid. Surface-initiated photoiniferter-mediated polymerization was employed to graft polymer brushes from gold surfaces. Different thickness of polymer brushes was controlled by varying UV irradiation time. The nonspecific adsorption from undiluted human blood serum and plasma was studied by surface plasmon resonance (SPR). With the polymer film as thin as 11-12 nm, the adsorption on pAspAA from serum and plasma was as low as 0.75 and 5.18 ng/cm(2), respectively, and 1.88 and 10.15 ng/cm(2), respectively, for pGluAA. The adsorption amount is comparable to or even better than other amino acid based zwitterionic polymers such as poly(serine methacrylate), poly(lysine methacrylamide), and poly(ornithine methacrylamide) and other widely used antifouling polymers such as poly(sulfobetaine methacrylate), even under thinner polymer film thickness. The pAspAA and pGluAA grafted surfaces also showed strong resistance to endothelial cell attachment. The possession of both zwitterionic structure and hydrophilic amide groups, biomimetic property, and multifunctionality make pAspAA and pGluAA promising candidates for biocompatible antifouling functionalizable materials.

  8. [Blood acid-base balance of sportsmen during physical activity].

    PubMed

    Petrushova, O P; Mikulyak, N I

    2014-01-01

    The aim of this study was to investigate the acid-base balance parameters in blood of sportsmen by physical activity. Before exercise lactate concentration in blood was normal. Carbon dioxide pressure (рСО2), bicarbonate concentration (НСО3 -), base excess (BE), were increased immediately after physical activity lactate concentration increased, while pH, BE, НСО3 -, рСО2 decreased in capillary blood of sportsmen. These changes show the development of lactate-acidosis which is partly compensated with bicarbonate buffering system and respiratory alkalosis. During postexercise recovery lactate concentration decreased, while рСО2, НСО3 -, BE increased. The results of this study can be used for diagnostics of acid-base disorders and their medical treatment for preservation of sportsmen physical capacity.

  9. PDMS-based gold electrode for sensing ascorbic acid.

    PubMed

    Xu, Qin; Bi, Lianhua; Zheng, Huxiang; Fan, Dahe; Wang, Wei

    2011-11-01

    Electrode with optical shapes is appreciated in microfluidics. In this article, we reported a flexible poly(dimethylsiloxane) (PDMS)-based gold electrode for ascorbic acid detection. Gold nanoparticles were chemically deposited on PDMS and the composite film was applied as working electrode. The electrode could undergo deformation and display good response performance without damage. This biosensor could give quick response to ascorbic acid (AA) (<5s) and the currents were linear with concentrations of AA in range of 0.023-7.00 mM and 30-100 mM, respectively. Limit of detection was 0.008 mM (S/N=3). This biosensor has been applied to determine ascorbic acid content in vitamin C tablets and the results were consistent with traditional iodometric method. PMID:21807485

  10. Food composition and acid-base balance: alimentary alkali depletion and acid load in herbivores.

    PubMed

    Kiwull-Schöne, Heidrun; Kiwull, Peter; Manz, Friedrich; Kalhoff, Hermann

    2008-02-01

    Alkali-enriched diets are recommended for humans to diminish the net acid load of their usual diet. In contrast, herbivores have to deal with a high dietary alkali impact on acid-base balance. Here we explore the role of nutritional alkali in experimentally induced chronic metabolic acidosis. Data were collected from healthy male adult rabbits kept in metabolism cages to obtain 24-h urine and arterial blood samples. Randomized groups consumed rabbit diets ad libitum, providing sufficient energy but variable alkali load. One subgroup (n = 10) received high-alkali food and approximately 15 mEq/kg ammonium chloride (NH4Cl) with its drinking water for 5 d. Another group (n = 14) was fed low-alkali food for 5 d and given approximately 4 mEq/kg NH4Cl daily for the last 2 d. The wide range of alimentary acid-base load was significantly reflected by renal base excretion, but normal acid-base conditions were maintained in the arterial blood. In rabbits fed a high-alkali diet, the excreted alkaline urine (pH(u) > 8.0) typically contained a large amount of precipitated carbonate, whereas in rabbits fed a low-alkali diet, both pH(u) and precipitate decreased considerably. During high-alkali feeding, application of NH4Cl likewise decreased pH(u), but arterial pH was still maintained with no indication of metabolic acidosis. During low-alkali feeding, a comparably small amount of added NH4Cl further lowered pH(u) and was accompanied by a significant systemic metabolic acidosis. We conclude that exhausted renal base-saving function by dietary alkali depletion is a prerequisite for growing susceptibility to NH4Cl-induced chronic metabolic acidosis in the herbivore rabbit.

  11. Acid-base titrations by stepwise addition of equal volumes of titrant with special reference to automatic titrations-II Theory of titration of mixtures of acids, polyprotic acids, acids in mixture with weak bases, and ampholytes.

    PubMed

    Pehrsson, L; Ingman, F; Johansson, S

    A general method for evaluating titration data for mixtures of acids and for acids in mixture with weak bases is presented. Procedures are given that do not require absolute [H]-data, i.e., relative [H]-data may be used. In most cases a very rough calibration of the electrode system is enough. Further, for simple systems, very approximate values of the stability constants are sufficient. As examples, the titration of the following are treated in some detail: a mixture of two acids, a diprotic acid, an acid in presence of its conjugate base, and an ampholyte.

  12. A low-cost microcontroller-based system to monitor crop temperature and water status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A prototype microcontroller-based system was developed to automate the measurement and recording of soil-moisture status and canopy-, air-, and soil-temperature levels in cropped fields. Measurements of these conditions within the cropping system are often used to assess plant stress, and can assis...

  13. Status of Problem-Based Learning Research in Pharmacy Education: A Call for Future Research.

    ERIC Educational Resources Information Center

    Cisneros, Robert M.; Salisbury-Glennon, Jill D.; Anderson-Harper, Heidi M.

    2002-01-01

    Reviews the current status of problem-based learning (PBL) research in pharmacy education, identifies trends and student outcomes from the pharmacy courses that have used PBL, presents a brief review of PBL research in medical education, and recommends future directions for PBL research in pharmacy education. (EV)

  14. Current Status of Evidence-Based Practice for Students with Intellectual Disability and Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    West, Elizabeth A.; McCollow, Meaghan; Umbarger, Gardner; Kidwell, James; Cote, Debra L.

    2013-01-01

    The purpose of this paper is to provide a current look at the status of evidence-based practice (EBP) for students with intellectual disability and autism spectrum disorders. Specifically, this paper will (1) provide an introduction to the history and evolution of the use of levels of evidence, (2) discuss the importance of EBPs, (3) identify…

  15. UAS-based infrared thermography for evaluating biofuel crop water status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Remote sensing of crop canopy temperature is a scientifically-based method to evaluate crop water stress at or near real time. Potential approaches for estimating biofuel crop water status from an unmanned aerial system (UAS’s) equipped with a thermal camera were evaluated in this study. An experime...

  16. Undermatched? School-Based Linguistic Status, College Going, and the Immigrant Advantage

    ERIC Educational Resources Information Center

    Callahan, Rebecca M.; Humphries, Melissa H.

    2016-01-01

    Considerable research investigates the immigrant advantage--the academic benefit first- and second-generation students experience relative to native-born peers. However, little work examines how school-based linguistic status may influence this advantage. Contradictory patterns exist: Research identifies both an immigrant advantage and a language…

  17. Reflection into China's Business English Teaching Practices Based on GDUFS Graduates' Employment Status

    ERIC Educational Resources Information Center

    Zhu, Wenzhong; Wu, Si; Guo, Tingting

    2009-01-01

    GDUFS, as one of China's top three foreign language universities with the longest history in business English teaching, has accumulated over 20-year experiences in this discipline. This research reflects into its business English teaching practices based on its graduates' employment status in recent years, and concludes that the students of…

  18. Folic acid deficiency impairs the gill health status associated with the NF-κB, MLCK and Nrf2 signaling pathways in the gills of young grass carp (Ctenopharyngodon idella).

    PubMed

    Shi, Lei; Feng, Lin; Jiang, Wei-Dan; Liu, Yang; Jiang, Jun; Wu, Pei; Zhao, Juan; Kuang, Sheng-Yao; Tang, Ling; Tang, Wu-Neng; Zhang, Yong-An; Zhou, Xiao-Qiu

    2015-11-01

    deficiency impaired fish gill health status via regulating gene expression of cytokines, tight junction proteins, antioxidant enzymes, NF-κB p65, MLCK and Nrf2. Based on percent weight gain, LZ activity and MDA content in the gills, the dietary folic acid requirements for young grass carp were 1.60, 2.07 and 2.08 mg kg(-1), respectively.

  19. Hard and soft acids and bases: structure and process.

    PubMed

    Reed, James L

    2012-07-01

    Under investigation is the structure and process that gives rise to hard-soft behavior in simple anionic atomic bases. That for simple atomic bases the chemical hardness is expected to be the only extrinsic component of acid-base strength, has been substantiated in the current study. A thermochemically based operational scale of chemical hardness was used to identify the structure within anionic atomic bases that is responsible for chemical hardness. The base's responding electrons have been identified as the structure, and the relaxation that occurs during charge transfer has been identified as the process giving rise to hard-soft behavior. This is in contrast the commonly accepted explanations that attribute hard-soft behavior to varying degrees of electrostatic and covalent contributions to the acid-base interaction. The ability of the atomic ion's responding electrons to cause hard-soft behavior has been assessed by examining the correlation of the estimated relaxation energies of the responding electrons with the operational chemical hardness. It has been demonstrated that the responding electrons are able to give rise to hard-soft behavior in simple anionic bases.

  20. Model for acid-base chemistry in nanoparticle growth (MABNAG)

    NASA Astrophysics Data System (ADS)

    Yli-Juuti, T.; Barsanti, K.; Hildebrandt Ruiz, L.; Kieloaho, A.-J.; Makkonen, U.; Petäjä, T.; Ruuskanen, T.; Kulmala, M.; Riipinen, I.

    2013-12-01

    Climatic effects of newly-formed atmospheric secondary aerosol particles are to a large extent determined by their condensational growth rates. However, all the vapours condensing on atmospheric nanoparticles and growing them to climatically relevant sizes are not identified yet and the effects of particle phase processes on particle growth rates are poorly known. Besides sulfuric acid, organic compounds are known to contribute significantly to atmospheric nanoparticle growth. In this study a particle growth model MABNAG (Model for Acid-Base chemistry in NAnoparticle Growth) was developed to study the effect of salt formation on nanoparticle growth, which has been proposed as a potential mechanism lowering the equilibrium vapour pressures of organic compounds through dissociation in the particle phase and thus preventing their evaporation. MABNAG is a model for monodisperse aqueous particles and it couples dynamics of condensation to particle phase chemistry. Non-zero equilibrium vapour pressures, with both size and composition dependence, are considered for condensation. The model was applied for atmospherically relevant systems with sulfuric acid, one organic acid, ammonia, one amine and water in the gas phase allowed to condense on 3-20 nm particles. The effect of dissociation of the organic acid was found to be small under ambient conditions typical for a boreal forest site, but considerable for base-rich environments (gas phase concentrations of about 1010 cm-3 for the sum of the bases). The contribution of the bases to particle mass decreased as particle size increased, except at very high gas phase concentrations of the bases. The relative importance of amine versus ammonia did not change significantly as a function of particle size. While our results give a reasonable first estimate on the maximum contribution of salt formation to nanoparticle growth, further studies on, e.g. the thermodynamic properties of the atmospheric organics, concentrations of low

  1. India-based neutrino observatory (INO): Physics reach and status report

    SciTech Connect

    Indumathi, D.

    2015-07-15

    We present a review of the physics reach and current status of the proposed India-based Neutrino Observatory (INO). We briefly outline details of the INO location and the present status of detector development. We then present the physics goals and simulation studies of the main detector, the magnetised Iron Calorimeter (ICAL) detector, to be housed in INO. The ICAL detector would make precision measurements of neutrino oscillation parameters with atmospheric neutrinos including a measurement of the neutrino mass hierarchy. Additional synergies with other experiments due to the complete insensitivity of ICAL to the CP phase are also discussed.

  2. Acid-base chemical mechanism of aspartase from Hafnia alvei.

    PubMed

    Yoon, M Y; Thayer-Cook, K A; Berdis, A J; Karsten, W E; Schnackerz, K D; Cook, P F

    1995-06-20

    An acid-base chemical mechanism is proposed for Hafnia alvei aspartase in which a proton is abstracted from C-3 of the monoanionic form of L-aspartate by an enzyme general base with a pK of 6.3-6.6 in the absence and presence of Mg2+. The resulting carbanion is presumably stabilized by delocalization of electrons into the beta-carboxyl with the assistance of a protonated enzyme group in the vicinity of the beta-carboxyl. Ammonia is then expelled with the assistance of a general acid group that traps an initially expelled NH3 as the final NH4+ product. In agreement with the function of the general acid group, potassium, an analog of NH4+, binds optimally when the group is unprotonated. The pK for the general acid is about 7 in the absence of Mg2+, but is increased by about a pH unit in the presence of Mg2+. Since the same pK values are observed in the pKi(succinate) and V/K pH profile, both enzyme groups must be in their optimum protonation state for efficient binding of reactant in the presence of Mg2+. At the end of a catalytic cycle, both the general base and general acid groups are in a protonation state opposite that in which they started when aspartate was bound. The presence of Mg2+ causes a pH-dependent activation of aspartase exhibited as a partial change in the V and V/Kasp pH profiles. When the aspartase reaction is run in D2O to greater than 50% completion no deuterium is found in the remaining aspartate, indicating that the site is inaccessible to solvent during the catalytic cycle.

  3. Bio-based production of organic acids with Corynebacterium glutamicum.

    PubMed

    Wieschalka, Stefan; Blombach, Bastian; Bott, Michael; Eikmanns, Bernhard J

    2013-03-01

    The shortage of oil resources, the steadily rising oil prices and the impact of its use on the environment evokes an increasing political, industrial and technical interest for development of safe and efficient processes for the production of chemicals from renewable biomass. Thus, microbial fermentation of renewable feedstocks found its way in white biotechnology, complementing more and more traditional crude oil-based chemical processes. Rational strain design of appropriate microorganisms has become possible due to steadily increasing knowledge on metabolism and pathway regulation of industrially relevant organisms and, aside from process engineering and optimization, has an outstanding impact on improving the performance of such hosts. Corynebacterium glutamicum is well known as workhorse for the industrial production of numerous amino acids. However, recent studies also explored the usefulness of this organism for the production of several organic acids and great efforts have been made for improvement of the performance. This review summarizes the current knowledge and recent achievements on metabolic engineering approaches to tailor C. glutamicum for the bio-based production of organic acids. We focus here on the fermentative production of pyruvate, L- and D-lactate, 2-ketoisovalerate, 2-ketoglutarate, and succinate. These organic acids represent a class of compounds with manifold application ranges, e.g. in pharmaceutical and cosmetics industry, as food additives, and economically very interesting, as precursors for a variety of bulk chemicals and commercially important polymers. PMID:23199277

  4. Bio-based production of organic acids with Corynebacterium glutamicum.

    PubMed

    Wieschalka, Stefan; Blombach, Bastian; Bott, Michael; Eikmanns, Bernhard J

    2013-03-01

    The shortage of oil resources, the steadily rising oil prices and the impact of its use on the environment evokes an increasing political, industrial and technical interest for development of safe and efficient processes for the production of chemicals from renewable biomass. Thus, microbial fermentation of renewable feedstocks found its way in white biotechnology, complementing more and more traditional crude oil-based chemical processes. Rational strain design of appropriate microorganisms has become possible due to steadily increasing knowledge on metabolism and pathway regulation of industrially relevant organisms and, aside from process engineering and optimization, has an outstanding impact on improving the performance of such hosts. Corynebacterium glutamicum is well known as workhorse for the industrial production of numerous amino acids. However, recent studies also explored the usefulness of this organism for the production of several organic acids and great efforts have been made for improvement of the performance. This review summarizes the current knowledge and recent achievements on metabolic engineering approaches to tailor C. glutamicum for the bio-based production of organic acids. We focus here on the fermentative production of pyruvate, L- and D-lactate, 2-ketoisovalerate, 2-ketoglutarate, and succinate. These organic acids represent a class of compounds with manifold application ranges, e.g. in pharmaceutical and cosmetics industry, as food additives, and economically very interesting, as precursors for a variety of bulk chemicals and commercially important polymers.

  5. Acid-Base Balance in Uremic Rats with Vascular Calcification

    PubMed Central

    Peralta-Ramírez, Alan; Raya, Ana Isabel; Pineda, Carmen; Rodríguez, Mariano; Aguilera-Tejero, Escolástico; López, Ignacio

    2014-01-01

    Background/Aims Vascular calcification (VC), a major complication in humans and animals with chronic kidney disease (CKD), is influenced by changes in acid-base balance. The purpose of this study was to describe the acid-base balance in uremic rats with VC and to correlate the parameters that define acid-base equilibrium with VC. Methods Twenty-two rats with CKD induced by 5/6 nephrectomy (5/6 Nx) and 10 nonuremic control rats were studied. Results The 5/6 Nx rats showed extensive VC as evidenced by a high aortic calcium (9.2 ± 1.7 mg/g of tissue) and phosphorus (20.6 ± 4.9 mg/g of tissue) content. Uremic rats had an increased pH level (7.57 ± 0.03) as a consequence of both respiratory (PaCO2 = 28.4 ± 2.1 mm Hg) and, to a lesser degree, metabolic (base excess = 4.1 ± 1 mmol/l) derangements. A high positive correlation between both anion gap (AG) and strong ion difference (SID) with aortic calcium (AG: r = 0.604, p = 0.02; SID: r = 0.647, p = 0.01) and with aortic phosphorus (AG: r = 0.684, p = 0.007; SID: r = 0.785, p = 0.01) was detected. Conclusions In an experimental model of uremic rats, VC showed high positive correlation with AG and SID. PMID:25177336

  6. The physiological assessment of acid-base balance.

    PubMed

    Howorth, P J

    1975-04-01

    Acid-base terminology including the sue of SI units is reviewed. The historical reasons why nomograms have been particularly used in acid-base work are discussed. The theoretical basis of the Henderson-Hasselbalch equation is considered. It is emphasized that the solubility of CO2 in plasma and the apparent first dissociation constant of carbonic acid are not chemical constants when applied to media of uncertain and varying composition such as blood plasma. The use of the Henderson-Hasselbalch equation in making hypothermia corrections for PCO2 is discussed. The Astrup system for the in vitro determination of blood gases and derived parameters is described and the theoretical weakness of the base excess concept stressed. A more clinically-oriented approach to the assessment of acid-base problems is presented. Measurement of blood [H+] and PCO2 are considered to be primary data which should be recorded on a chart with in vivo CO2-titration lines (see below). Clinical information and results of other laboratory investigations such as plasma bicarbonate, PO2,P50 are then to be considered together with the primary data. In order to interpret this combined information it is essential to take into account the known ventilatory response to metabolic acidosis and alkalosis, and the renal response to respiratory acidosis and alkalosis. The use is recommended of a chart showing the whole-body CO2-titration points obtained when patients with different initial levels of non-respiratory [H+] are ventilated. A number of examples are given of the use of this [H+] and PCO2 in vivo chart in the interpretation of acid-base data. The aetiology, prognosis and treatment of metabolic alkalosis is briefly reviewed. Treatment with intravenous acid is recommended for established cases. Attention is drawn to the possibility of iatrogenic production of metabolic alkalosis. Caution is expressed over the use of intravenous alkali in all but the severest cases of metabolic acidosis. The role of

  7. Status of Real-Time Laser Based Ion Engine Diagnostics at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Domonkos, Matthew T.; Williams, George J., Jr.

    2001-01-01

    The development status of laser based erosion diagnostics for ion engines at the NASA Glenn Research Center is discussed. The diagnostics are being developed to enhance component life-prediction capabilities. A direct measurement of the erosion product density using laser induced fluorescence (LIF) is described. Erosion diagnostics based upon evaluation of the ion dynamics are also under development, and the basic approach is presented. The planned implementation of the diagnostics is discussed.

  8. Acid and base stress and transcriptomic responses in Bacillus subtilis.

    PubMed

    Wilks, Jessica C; Kitko, Ryan D; Cleeton, Sarah H; Lee, Grace E; Ugwu, Chinagozi S; Jones, Brian D; BonDurant, Sandra S; Slonczewski, Joan L

    2009-02-01

    Acid and base environmental stress responses were investigated in Bacillus subtilis. B. subtilis AG174 cultures in buffered potassium-modified Luria broth were switched from pH 8.5 to pH 6.0 and recovered growth rapidly, whereas cultures switched from pH 6.0 to pH 8.5 showed a long lag time. Log-phase cultures at pH 6.0 survived 60 to 100% at pH 4.5, whereas cells grown at pH 7.0 survived <15%. Cells grown at pH 9.0 survived 40 to 100% at pH 10, whereas cells grown at pH 7.0 survived <5%. Thus, growth in a moderate acid or base induced adaptation to a more extreme acid or base, respectively. Expression indices from Affymetrix chip hybridization were obtained for 4,095 protein-encoding open reading frames of B. subtilis grown at external pH 6, pH 7, and pH 9. Growth at pH 6 upregulated acetoin production (alsDS), dehydrogenases (adhA, ald, fdhD, and gabD), and decarboxylases (psd and speA). Acid upregulated malate metabolism (maeN), metal export (czcDO and cadA), oxidative stress (catalase katA; OYE family namA), and the SigX extracytoplasmic stress regulon. Growth at pH 9 upregulated arginine catabolism (roc), which generates organic acids, glutamate synthase (gltAB), polyamine acetylation and transport (blt), the K(+)/H(+) antiporter (yhaTU), and cytochrome oxidoreductases (cyd, ctaACE, and qcrC). The SigH, SigL, and SigW regulons were upregulated at high pH. Overall, greater genetic adaptation was seen at pH 9 than at pH 6, which may explain the lag time required for growth shift to high pH. Low external pH favored dehydrogenases and decarboxylases that may consume acids and generate basic amines, whereas high external pH favored catabolism-generating acids.

  9. Acid-base properties of bentonite rocks with different origins.

    PubMed

    Nagy, Noémi M; Kónya, József

    2006-03-01

    Five bentonite samples (35-47% montmorillonite) from a Sarmatian sediment series with bentonite sites around Sajóbábony (Hungary) is studied. Some of these samples were tuffogenic bentonite (sedimentary), the others were bentonitized tuff with volcano sedimentary origin. The acid-base properties of the edge sites were studied by potentiometric titrations and surface complexation modeling. It was found that the number and the ratio of silanol and aluminol sites as well as the intrinsic stability constants are different for the sedimentary bentonite and bentonitized tuff. The characteristic properties of the edges sites depend on the origins. The acid-base properties are compared to other commercial and standard bentonites.

  10. Self-glazing ceramic tiles based on acidic igneous glasses

    SciTech Connect

    Merkin, A.P.; Nanazashvili, V.I.

    1988-07-01

    A technology was derived to produce self-glazing ceramic tiles based on single-component systems of acidic igneous (volcanic) glasses. A weakly alkaline solution of NaOH or KOH was used as the sealing water to activate the sintering process. Tests conducted on the self-glazing ceramic tiles showed that their water absorption amounts to 2.5-8%, linear shrinkage is 3.2-7%, and frost resistance amounts to 35-70 cycles. The application of acidic igneous glasses as the main raw material for the production of ceramic facing tiles made it possible to widen the raw material base and simplify the technology for fabricating ceramic facing tiles at lower cost. The use of waste products when processing perlite-bearing rocks, when carrying out mining and cutting of tuffs, slags, and tuff breccia for recovering cut materials was recommended.

  11. Relationship between acid–base status and inflammation in the critically ill

    PubMed Central

    2014-01-01

    Introduction There is a complex interplay between changes in acid–base components and inflammation. This manuscript aims to explore associations between plasma cytokines and chemokines and acid–base status on admission to intensive care. Methods We conducted a prospective cohort study in a 13-bed ICU in a tertiary-care center in Brazil. 87 unselected patients admitted to the ICU during a 2-year period were included. We measured multiple inflammatory mediators in plasma using multiplex assays and evaluated the association between mediator concentrations and acid–base variables using a variety of statistical modeling approaches, including generalized linear models, multiadaptive regression splines and principal component analysis. Results We found a positive association between strong ion gap (SIG) and plasma concentrations of interleukin (IL)6, 8, 10 and tumor necrosis factor (TNF); whereas albumin was negatively associated with IL6, IL7, IL8, IL10, TNF and interferon (IFN)α. Apparent strong ion difference (SIDa) was negatively associated with IL10 and IL17. A principal component analysis including SAPS 3 indicated that the association between acid–base components and inflammatory status was largely independent of illness severity, with both increased SIG and decreased SIDa (both drivers of acidosis) associated with increased inflammation. Conclusion Acid–base variables (especially increased SIG, decreased albumin and decreased SIDa) on admission to ICU are associated with immunological activation. These findings should encourage new research into the effects of acid–base status on inflammation. PMID:25034180

  12. [Injuries caused by acids and bases - emergency treatment].

    PubMed

    Reifferscheid, Florian; Stuhr, Markus; Kaiser, Guido; Freudenberg, Matthias; Kerner, Thoralf

    2014-06-01

    Emergency medical care for injuries caused by acids and bases is challenging for rescue services. They have to deal with operational safety, detection of the toxic agent, emergency medical care of the patient and handling of the rescue mission. Because of the rareness of such situations experience and routine are largely missing. This article highlights some basic points for the therapy and provides support for such rescue missions.

  13. Synthesis of bio-based methacrylic acid by decarboxylation of itaconic acid and citric acid catalyzed by solid transition-metal catalysts.

    PubMed

    Le Nôtre, Jérôme; Witte-van Dijk, Susan C M; van Haveren, Jacco; Scott, Elinor L; Sanders, Johan P M

    2014-09-01

    Methacrylic acid, an important monomer for the plastics industry, was obtained in high selectivity (up to 84%) by the decarboxylation of itaconic acid using heterogeneous catalysts based on Pd, Pt and Ru. The reaction takes place in water at 200-250 °C without any external added pressure, conditions significantly milder than those described previously for the same conversion with better yield and selectivity. A comprehensive study of the reaction parameters has been performed, and the isolation of methacrylic acid was achieved in 50% yield. The decarboxylation procedure is also applicable to citric acid, a more widely available bio-based feedstock, and leads to the production of methacrylic acid in one pot in 41% selectivity. Aconitic acid, the intermediate compound in the pathway from citric acid to itaconic acid was also used successfully as a substrate. PMID:25045161

  14. Influence of ions on aqueous acid-base reactions.

    PubMed

    Cox, M Jocelyn; Siwick, Bradley J; Bakker, Huib J

    2009-01-12

    We study the effects of bromide salts on the rate and mechanism of the aqueous proton/deuteron-transfer reaction between the photoacid 8-hydroxy-1,3,6-pyrenetrisulfonic acid (HPTS) and the base acetate. The proton/deuteron release is triggered by exciting HPTS with 400 nm femtosecond laser pulses. Probing the electronic and vibrational resonances of the photoacid, the conjugate photobase, the hydrated proton/deuteron and the accepting base with femtosecond visible and mid-infrared pulses monitors the proton transfer. Two reaction channels are identified: 1) direct long-range proton transfer over hydrogen-bonded water bridges that connect the acid and base and 2) acid dissociation to produce fully solvated protons followed by proton scavenging from solution by acetate. We observe that the addition of salt affects the long-range reaction pathway, and reduces both the rate at which protons are released to solution by HPTS and the rate at which solvated protons are scavenged from solution by acetate. We study the dependence of these effects on the nature and concentration of the dissolved salt.

  15. Polyunsaturated fatty acid status in attention deficit hyperactivity disorder, depression, and Alzheimer's disease: towards an omega-3 index for mental health?

    PubMed

    Milte, Catherine M; Sinn, Natalie; Howe, Peter R C

    2009-10-01

    Interest in the role of polyunsaturated fatty acids (PUFAs), particularly long-chain (LC) omega-3 (n-3) PUFAs, in mental health is increasing. This review investigates whether n-3 PUFA levels are abnormal in people with three prevalent mental health problems - attention deficit hyperactivity disorder, depression, and dementia. Data sources included PubMed, Web of Science, and bibliographies of papers published in English that describe PUFA levels in the circulation of individuals who have these mental health conditions. Although abnormal blood PUFA levels were reported in a number of studies, weighted comparisons of PUFA status showed no significant differences overall between people with mental health problems and controls. Whether those with low n-3 PUFA status are likely to be more responsive to n-3 PUFA supplementation is not yet resolved. Further studies assessing PUFA levels and mental status with greater uniformity are required in order to clarify the relationship between LC n-3 PUFA status and mental health.

  16. Lewis base activation of Lewis acids: development of a Lewis base catalyzed selenolactonization.

    PubMed

    Denmark, Scott E; Collins, William R

    2007-09-13

    The concept of Lewis base activation of Lewis acids has been applied to the selenolactonization reaction. Through the use of substoichiometric amounts of Lewis bases with "soft" donor atoms (S, Se, P) significant rate enhancements over the background reaction are seen. Preliminary mechanistic investigations have revealed the resting state of the catalyst as well as the significance of a weak Brønsted acid promoter.

  17. [Nutrition, acid-base metabolism, cation-anion difference and total base balance in humans].

    PubMed

    Mioni, R; Sala, P; Mioni, G

    2008-01-01

    The relationship between dietary intake and acid-base metabolism has been investigated in the past by means of the inorganic cation-anion difference (C(+)(nm)-A(-)(nm)) method based on dietary ash-acidity titration after the oxidative combustion of food samples. Besides the inorganic components of TA (A(-)(nm)-C(+)(nm)), which are under renal control, there are also metabolizable components (A(-)(nm)-C(+)(nm)) of TA, which are under the control of the intermediate metabolism. The whole body base balance, NBb(W), is obtained only by the application of C(+)(nm)-A(-)(nm) to food, feces and urine, while the metabolizable component (A(-)(nm)-C(+)(nm)) is disregarded. A novel method has been subsequently suggested to calculate the net balance of fixed acid, made up by the difference between the input of net endogenous acid production: NEAP = SO(4)(2-)+A(-)(m)-(C(+)(nm)-A(-)(nm)), and the output of net acid excretion: NAE = TA + NH(4)(+) - HCO(3)(-). This approach has been criticized because 1) it includes metabolizable acids, whose production cannot be measured independently; 2) the specific control of metabolizable acid and base has been incorrectly attributed to the kidney; 3) the inclusion of A-m in the balance input generates an acid overload; 4) the object of measurement in making up a balance has to be the same, a condition not fulfilled as NEAP is different from NAE. Lastly, by rearranging the net balance of the acid equation, the balance of nonmetabolizable acid equation is obtained. Therefore, any discrepancy between these two equations is due to the inaccuracy in the urine measurement of metabolizable cations and/or anions.

  18. Acid Base Equilibrium in a Lipid/Water Gel

    NASA Astrophysics Data System (ADS)

    Streb, Kristina K.; Ilich, Predrag-Peter

    2003-12-01

    A new and original experiment in which partition of bromophenol blue dye between water and lipid/water gel causes a shift in the acid base equilibrium of the dye is described. The dye-absorbing material is a monoglyceride food additive of plant origin that mixes freely with water to form a stable cubic phase gel; the nascent gel absorbs the dye from aqueous solution and converts it to the acidic form. There are three concurrent processes taking place in the experiment: (a) formation of the lipid/water gel, (b) absorption of the dye by the gel, and (c) protonation of the dye in the lipid/water gel environment. As the aqueous solution of the dye is a deep purple-blue color at neutral pH and yellow at acidic pH the result of these processes is visually striking: the strongly green-yellow particles of lipid/water gel are suspended in purple-blue aqueous solution. The local acidity of the lipid/water gel is estimated by UV vis spectrophotometry. This experiment is an example of host-guest (lipid/water gel dye) interaction and is suitable for project-type biophysics, physical chemistry, or biochemistry labs. The experiment requires three, 3-hour lab sessions, two of which must not be separated by more than two days.

  19. Acid-base chemistry of frustrated water at protein interfaces.

    PubMed

    Fernández, Ariel

    2016-01-01

    Water molecules at a protein interface are often frustrated in hydrogen-bonding opportunities due to subnanoscale confinement. As shown, this condition makes them behave as a general base that may titrate side-chain ammonium and guanidinium cations. Frustration-based chemistry is captured by a quantum mechanical treatment of proton transference and shown to remove same-charge uncompensated anticontacts at the interface found in the crystallographic record and in other spectroscopic information on the aqueous interface. Such observations are untenable within classical arguments, as hydronium is a stronger acid than ammonium or guanidinium. Frustration enables a directed Grotthuss mechanism for proton transference stabilizing same-charge anticontacts.

  20. Acid-base chemistry of frustrated water at protein interfaces.

    PubMed

    Fernández, Ariel

    2016-01-01

    Water molecules at a protein interface are often frustrated in hydrogen-bonding opportunities due to subnanoscale confinement. As shown, this condition makes them behave as a general base that may titrate side-chain ammonium and guanidinium cations. Frustration-based chemistry is captured by a quantum mechanical treatment of proton transference and shown to remove same-charge uncompensated anticontacts at the interface found in the crystallographic record and in other spectroscopic information on the aqueous interface. Such observations are untenable within classical arguments, as hydronium is a stronger acid than ammonium or guanidinium. Frustration enables a directed Grotthuss mechanism for proton transference stabilizing same-charge anticontacts. PMID:26762189

  1. Acid-base disorders in calves with chronic diarrhea.

    PubMed

    Bednarski, M; Kupczyński, R; Sobiech, P

    2015-01-01

    The aim of this study was to analyze disorders of acid-base balance in calves with chronic diarrhea caused by mixed, viral, bacterial and Cryptosporydium parvum infection. We compared results ob- tained with the classic model (Henderson-Hasselbalch) and strong ion approach (the Steward model). The study included 36 calves aged between 14 and 21 days. The calves were allocated to three groups: I - (control) non-diarrheic calves, group II - animals with compensated acid-base imbalance and group III calves with compensated acid-base disorders and hypoalbuminemia. Plasma concentrations of Na+, K+, Cl-, C12+, Mg2+, P, albumin and lactate were measured. In the classic model, acid-base balance was determined on the basis of blood pH, pCO2, HCO3-, BE and anion gap. In the strong ion model, strong ion difference (SID), effective strong anion difference, total plasma concentration of nonvolatile buffers (A(Tot)) and strong ion gap (SIG) were measured. The control calves and the animals from groups II and III did not differ significantly in terms of their blood pH. The plasma concentration of HCO3-, BE and partial pressure of CO2 in animals from the two groups with chronic diarrhea were significantly higher than those found in the controls. The highest BE (6.03 mmol/l) was documented in calves from group II. The animals from this group presented compensation resulted from activation of metabolic mechanisms. The calves with hypoal- buminemia (group III) showed lower plasma concentrations of albumin (15.37 g/L), Cl (74.94 mmol/L), Mg2+ (0.53 mmol/L), P (1.41 mmol/L) and higher value of anion gap (39.03 mmol/L). This group III presented significantly higher SID3 (71.89 mmol/L), SID7 (72.92 mmol/L) and SIG (43.53 mmol/L) values than animals from the remaining groups (P < 0.01), whereas A(Tot) (6.82 mmol/L) were significantly lower. The main finding of the correlation study was the excellent relationship between the AGcorr and SID3, SID7, SIG. In conclusion, chronic diarrhea leads

  2. What are the living conditions and health status of those who don’t report their migration status? a population-based study in Chile

    PubMed Central

    2012-01-01

    Background Undocumented immigrants are likely to be missing from population databases, making it impossible to identify an accurate sampling frame in migration research. No population-based data has been collected in Chile regarding the living conditions and health status of undocumented immigrants. However, the CASEN survey (Caracterizacion Socio- Economica Nacional) asked about migration status in Chile for the first time in 2006 and provides an opportunity to set the base for future analysis of available migration data. We explored the living conditions and health of self-reported immigrants and respondents who preferred not to report their migration status in this survey. Methods Cross-sectional secondary analysis of CASEN survey in Chile in 2006. Outcomes: any disability, illness/accident, hospitalization/surgery, cancer/chronic condition (all binary variables); and the number of medical/emergency attentions received (count variables). Covariates: Demographics (age, sex, marital status, urban/rural, ethnicity), socioeconomic status (education level, employment status and household income), and material standard of living (overcrowding, sanitation, housing quality). Weighted regression models were estimated for each health outcome, crude and adjusted by sets of covariates, in STATA 10.0. Results About 1% of the total sample reported being immigrants and 0.7% preferred not to report their migration status (Migration Status - Missing Values; MS-MV). The MS-MV lived in more deprived conditions and reported a higher rate of health problems than immigrants. Some gender differences were observed by health status among immigrants and the MS-MV but they were not statistically significant. Regressions indicated that age, sex, SES and material factors consistently affected MS-MVs’ chance of presenting poor health and these patterns were different to those found among immigrants. Great heterogeneity in both the MS-MV and the immigrants, as indicated by wide confidence

  3. Update on the management of rosacea: a status report on the current role and new horizons with topical azelaic acid.

    PubMed

    Del Rosso, James Q; Kircik, Leon H

    2014-12-01

    Azelaic acid (AzA) 15% gel has been available in the United States for slightly over a decade, approved for treatment of the inflammatory lesions (papules and pustules) of rosacea. Efficacy and safety have been established in multiple studies both as monotherapy and in combination with oral doxycycline. Azelaic acid 15% gel has been shown not to induce epidermal permeability barrier impairment, and proper skin care reduces the likelihood of neurosensory adverse effects of stinging and burning that can affect a subset of patients with rosacea. Azelaic acid 15% gel appears to produce a quicker onset of clinical effect than metronidazole in some patients when either agent is used in combination with subantimicrobial dose doxycycline; however, both topical agents are effective when used in this combination approach for papulopustular rosacea (PPR). Although more information is needed on the modes of action of AzA in the treatment of rosacea, downregulation of the cathelicidin pathway appears to be one operative mode of action based on in vitro and in vivo studies, including data from patients treated with AzA 15% gel for PPR. Azelaic acid 15% foam is currently in the latter stages of development for PPR, with pivotal studies demonstrating efficacy and favorable tolerability, including a very low incidence of stinging, burning, and itching even without the use of designated skin care products.

  4. Procedure for the quantitative determination of mixtures of nucleic Acid components based on multivariate spectrophotometric Acid-base titrations.

    PubMed

    Saurina, J; Hernández-Cassou, S; Tauler, R; Izquierdo-Ridorsa, A

    1999-01-01

    A new procedure for the quantitative determination of mixtures of nucleic acid components, based on continuous spectrophotometric acid-base titrations and multivariate curve resolution, is proposed. The procedure simultaneously takes into account the spectroscopic and acid-base properties of the compounds, which leads to a higher selectivity. Furthermore, quantitative determination of an analyte in a complex mixture is performed using a synthetic solution as standard containing only the analyte of interest. An intrinsic difficulty in the analysis of spectrometric titration data is the presence of rank deficiency due to closure for the mixtures of two or more compounds. An additional problem can be encountered in some mixtures if species spectra or species concentration profiles are practically identical (rank overlap). However, even in the presence of these rank difficulties, accurate quantitation with prediction errors lower than 5% was obtained. The presence of unknown and uncalibrated interferences in the samples does not affect the quantitative determination of the analyte of interest. The proposed procedure was successfully applied to the analysis of real samples (pharmaceuticals) using synthetic external standards.

  5. Fatty acid-based polyurethane films for wound dressing applications.

    PubMed

    Gultekin, Guncem; Atalay-Oral, Cigdem; Erkal, Sibel; Sahin, Fikret; Karastova, Djursun; Tantekin-Ersolmaz, S Birgul; Guner, F Seniha

    2009-01-01

    Fatty acid-based polyurethane films were prepared for use as potential wound dressing material. The polymerization reaction was carried out with or without catalyst. Polymer films were prepared by casting-evaporation technique with or without crosslink-catalyst. The film prepared from uncatalyzed reaction product with crosslink-catalyst gave slightly higher crosslink density. The mechanical tests showed that, the increase in the tensile strength and decrease in the elongation at break is due to the increase in the degree of crosslinking. All films were flexible, and resisted to acid solution. The films prepared without crosslink-catalyst were more hydrophilic, absorbed more water. The highest permeability values were generally obtained for the films prepared without crosslink catalyst. Both the direct contact method and the MMT test were applied for determination of cytotoxicity of polymer films and the polyurethane film prepared from uncatalyzed reaction product without crosslink-catalyst showed better biocompatibility property, closest to the commercial product, Opsite.

  6. Fatty acid-based polyurethane films for wound dressing applications.

    PubMed

    Gultekin, Guncem; Atalay-Oral, Cigdem; Erkal, Sibel; Sahin, Fikret; Karastova, Djursun; Tantekin-Ersolmaz, S Birgul; Guner, F Seniha

    2009-01-01

    Fatty acid-based polyurethane films were prepared for use as potential wound dressing material. The polymerization reaction was carried out with or without catalyst. Polymer films were prepared by casting-evaporation technique with or without crosslink-catalyst. The film prepared from uncatalyzed reaction product with crosslink-catalyst gave slightly higher crosslink density. The mechanical tests showed that, the increase in the tensile strength and decrease in the elongation at break is due to the increase in the degree of crosslinking. All films were flexible, and resisted to acid solution. The films prepared without crosslink-catalyst were more hydrophilic, absorbed more water. The highest permeability values were generally obtained for the films prepared without crosslink catalyst. Both the direct contact method and the MMT test were applied for determination of cytotoxicity of polymer films and the polyurethane film prepared from uncatalyzed reaction product without crosslink-catalyst showed better biocompatibility property, closest to the commercial product, Opsite. PMID:18839285

  7. Carboxylic acid free novel isocyanide-based reactions.

    PubMed

    Soeta, Takahiro; Ukaji, Yutaka

    2014-02-01

    In order to develop a practical method for the construction of drug-like and heterocyclic compounds, we have designed a novel Passerini- or Ugi-type reaction system where a compound (which we write in the general form as Z-X) composed of an electrophilic (Z) and a nucleophilic group (X) could essentially perform the same function as the carboxylic acid. Based on this concept, we have developed the O-silylative Passerini reaction and the borinic acid catalyzed α-addition of isocyanides to aldehydes and water. In addition, we have designed and demonstrated the addition reaction of isocyanides to nitrones in the presence of TMSCl to afford the corresponding 1,2,3,4-tetrahydroisoquinoline-1-carboxyamides. Furthermore, a novel [5 + 1] cycloaddition of isocyanide was explored with C,N-cyclic N'-acyl azomethine imines as a "1,5-dipole" via a strategy involving intramolecular trapping of the isocyanide.

  8. Nucleic acid-based tissue biomarkers of urologic malignancies.

    PubMed

    Dietrich, Dimo; Meller, Sebastian; Uhl, Barbara; Ralla, Bernhard; Stephan, Carsten; Jung, Klaus; Ellinger, Jörg; Kristiansen, Glen

    2014-08-01

    Molecular biomarkers play an important role in the clinical management of cancer patients. Biomarkers allow estimation of the risk of developing cancer; help to diagnose a tumor, ideally at an early stage when cure is still possible; and aid in monitoring disease progression. Furthermore, they hold the potential to predict the outcome of the disease (prognostic biomarkers) and the response to therapy (predictive biomarkers). Altogether, biomarkers will help to avoid tumor-related deaths and reduce overtreatment, and will contribute to increased survival and quality of life in cancer patients due to personalized treatments. It is well established that the process of carcinogenesis is a complex interplay between genomic predisposition, acquired somatic mutations, epigenetic changes and genomic aberrations. Within this complex interplay, nucleic acids, i.e. RNA and DNA, play a fundamental role and therefore represent ideal candidates for biomarkers. They are particularly promising candidates because sequence-specific hybridization and amplification technologies allow highly accurate and sensitive assessment of these biomarker levels over a broad dynamic range. This article provides an overview of nucleic acid-based biomarkers in tissues for the management of urologic malignancies, i.e. tumors of the prostate, testis, kidney, penis, urinary bladder, renal pelvis, ureter and other urinary organs. Special emphasis is put on genomic, transcriptomic and epigenomic biomarkers (SNPs, mutations [genomic and mitochondrial], microsatellite instabilities, viral and bacterial DNA, DNA methylation and hydroxymethylation, mRNA expression, and non-coding RNAs [lncRNA, miRNA, siRNA, piRNA, snRNA, snoRNA]). Due to the multitude of published biomarker candidates, special focus is given to the general applicability of different molecular classes as biomarkers and some particularly promising nucleic acid biomarkers. Furthermore, specific challenges regarding the development and clinical

  9. Bio-based production of organic acids with Corynebacterium glutamicum

    PubMed Central

    Wieschalka, Stefan; Blombach, Bastian; Bott, Michael; Eikmanns, Bernhard J

    2013-01-01

    The shortage of oil resources, the steadily rising oil prices and the impact of its use on the environment evokes an increasing political, industrial and technical interest for development of safe and efficient processes for the production of chemicals from renewable biomass. Thus, microbial fermentation of renewable feedstocks found its way in white biotechnology, complementing more and more traditional crude oil-based chemical processes. Rational strain design of appropriate microorganisms has become possible due to steadily increasing knowledge on metabolism and pathway regulation of industrially relevant organisms and, aside from process engineering and optimization, has an outstanding impact on improving the performance of such hosts. Corynebacterium glutamicum is well known as workhorse for the industrial production of numerous amino acids. However, recent studies also explored the usefulness of this organism for the production of several organic acids and great efforts have been made for improvement of the performance. This review summarizes the current knowledge and recent achievements on metabolic engineering approaches to tailor C. glutamicum for the bio-based production of organic acids. We focus here on the fermentative production of pyruvate, l-and d-lactate, 2-ketoisovalerate, 2-ketoglutarate, and succinate. These organic acids represent a class of compounds with manifold application ranges, e.g. in pharmaceutical and cosmetics industry, as food additives, and economically very interesting, as precursors for a variety of bulk chemicals and commercially important polymers. Funding Information Work in the laboratories of the authors was supported by the Fachagentur Nachwachsende Rohstoffe (FNR) of the Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz (BMELV; FNR Grants 220-095-08A and 220-095-08D; Bio-ProChemBB project, ERA-IB programme), by the Deutsche Bundesstiftung Umwelt (DBU Grant AZ13040/05) and the Evonik Degussa AG. PMID

  10. DEOXYRIBONUCLEIC ACID BASE COMPOSITION OF PROTEUS AND PROVIDENCE ORGANISMS

    PubMed Central

    Falkow, Stanley; Ryman, I. R.; Washington, O.

    1962-01-01

    Falkow, Stanley (Walter Reed Army Institute of Research, Washington D.C.), I. R. Ryman, and O. Washington. Deoxyribonucleic acid base composition of Proteus and Providence organisms. J. Bacteriol. 83:1318–1321. 1962.—Deoxyribonucleic acids (DNA) from various species of Proteus and of Providence bacteria have been examined for their guanine + cytosine (GC) content. P. vulgaris, P. mirabilis, and P. rettgeri possess essentially identical mean GC contents of 39%, and Providence DNA has a GC content of 41.5%. In marked contrast, P. morganii DNA was found to contain 50% GC. The base composition of P. morganii is only slightly lower than those observed for representatives of the Escherichia, Shigella, and Salmonella groups. Aerobacter and Serratia differ significantly from the other members of the family by their relatively high GC content. Since a minimal requirement for genetic compatibility among different species appears to be similarity of their DNA base composition, it is suggested that P. morganii is distinct genetically from the other species of Proteus as well as Providence strains. The determination of the DNA base composition of microorganisms is important for its predictive information. This information should prove of considerable value in investigating genetic and taxonomic relationships among bacteria. PMID:13891463

  11. Stillbirth rates and folic acid and zinc status in low-socioeconomic pregnant women of Brazilian Amazon.

    PubMed

    Lehti, K K

    1993-01-01

    Twenty-five women in their first trimester and 25 women in their third trimester of pregnancy were randomly chosen from the slum areas of eight towns in the Brazilian Amazon (Manaus, Sao Luis, Boa Vista, Porto Velho, Sao Gabriel, Santarem, Tefe, and Benjamin Constant). Blood samples were removed from the subjects for folic acid and zinc analyses, and the women were asked questions about whether they had suffered from complications during previous pregnancies. It was found that the stillbirth rates reported ranged from 0 to 20/1000 pregnancies. The town that had the highest stillbirth rate (Santarem) also had the highest percentage of women with deficient erythrocyte (red blood cell, RBC) folate status. All of the women in Santarem also had deficient serum folate levels in both trimesters of pregnancy, as well as the lowest average RBC folate value in the third trimester of pregnancy. The same town was also one of two in which the pregnant women had the lowest mean serum zinc levels in the third trimester.

  12. IGF-I regulates redox status in breast cancer cells by activating the amino acid transport molecule xC-.

    PubMed

    Yang, Yuzhe; Yee, Douglas

    2014-04-15

    Insulin-like growth factors (IGF) stimulate cell growth in part by increasing amino acid uptake. xCT (SLC7A11) encodes the functional subunit of the cell surface transport system xC(-), which mediates cystine uptake, a pivotal step in glutathione synthesis and cellular redox control. In this study, we show that IGF-I regulates cystine uptake and cellular redox status by activating the expression and function of xCT in estrogen receptor-positive (ER(+)) breast cancer cells by a mechanism that relies on the IGF receptor substrate-1 (IRS-1). Breast cancer cell proliferation mediated by IGF-I was suppressed by attenuating xCT expression or blocking xCT activity with the pharmacologic inhibitor sulfasalazine (SASP). Notably, SASP sensitized breast cancer cells to inhibitors of the type I IGF receptor (IGF-IR) in a manner reversed by the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine. Thus, IGF-I promoted the proliferation of ER(+) breast cancer cells by regulating xC(-) transporter function to protect cancer cells from ROS in an IRS-1-dependent manner. Our findings suggest that inhibiting xC(-) transporter function may synergize with modalities that target the IGF-IR to heighten their therapeutic effects.

  13. Cardiac connexin-43 and PKC signaling in rats with altered thyroid status without and with omega-3 fatty acids intake.

    PubMed

    Szeiffová Bačová, B; Egan Beňová, T; Viczenczová, C; Soukup, T; Rauchová, H; Pavelka, S; Knezl, V; Barančík, M; Tribulová, N

    2016-09-19

    Thyroid hormones are powerful modulators of heart function and susceptibility to arrhythmias via both genomic and non-genomic actions. We aimed to explore expression of electrical coupling protein connexin-43 (Cx43) in the heart of rats with altered thyroid status and impact of omega-3 polyunsaturated fatty acids (omega-3) supplementation. Adult male Lewis rats were divided into following six groups: euthyroid controls, hyperthyroid (treated with T(3)) and hypothyroid (treated with methimazol) with or without six-weeks lasting supplementation with omega-3 (20 mg/100 g/day). Left and right ventricles, septum and atria were used for immunoblotting of Cx43 and protein kinase C (PKC). Total expression of Cx43 and its phosphorylated forms were significantly increased in all heart regions of hypothyroid rats compared to euthyroid controls. In contrast, the total levels of Cx43 and its functional phosphorylated forms were decreased in atria and left ventricle of hyperthyroid rats. In parallel, the expression of PKC epsilon that phosphorylates Cx43, at serine 368, was increased in hypothyroid but decreased in hyperthyroid rat hearts. Omega-3 intake did not significantly affect either Cx43 or PKC epsilon alterations. In conclusion, there is an inverse relationship between expression of cardiac Cx43 and the levels of circulating thyroid hormones. It appears that increased propensity of hyperthyroid while decreased of hypothyroid individuals to malignant arrhythmias may be in part attributed to the changes in myocardial Cx43.

  14. Cardiac connexin-43 and PKC signaling in rats with altered thyroid status without and with omega-3 fatty acids intake.

    PubMed

    Szeiffová Bačová, B; Egan Beňová, T; Viczenczová, C; Soukup, T; Rauchová, H; Pavelka, S; Knezl, V; Barančík, M; Tribulová, N

    2016-09-19

    Thyroid hormones are powerful modulators of heart function and susceptibility to arrhythmias via both genomic and non-genomic actions. We aimed to explore expression of electrical coupling protein connexin-43 (Cx43) in the heart of rats with altered thyroid status and impact of omega-3 polyunsaturated fatty acids (omega-3) supplementation. Adult male Lewis rats were divided into following six groups: euthyroid controls, hyperthyroid (treated with T(3)) and hypothyroid (treated with methimazol) with or without six-weeks lasting supplementation with omega-3 (20 mg/100 g/day). Left and right ventricles, septum and atria were used for immunoblotting of Cx43 and protein kinase C (PKC). Total expression of Cx43 and its phosphorylated forms were significantly increased in all heart regions of hypothyroid rats compared to euthyroid controls. In contrast, the total levels of Cx43 and its functional phosphorylated forms were decreased in atria and left ventricle of hyperthyroid rats. In parallel, the expression of PKC epsilon that phosphorylates Cx43, at serine 368, was increased in hypothyroid but decreased in hyperthyroid rat hearts. Omega-3 intake did not significantly affect either Cx43 or PKC epsilon alterations. In conclusion, there is an inverse relationship between expression of cardiac Cx43 and the levels of circulating thyroid hormones. It appears that increased propensity of hyperthyroid while decreased of hypothyroid individuals to malignant arrhythmias may be in part attributed to the changes in myocardial Cx43. PMID:27643942

  15. Superabsorbent biphasic system based on poly(lactic acid) and poly(acrylic acid)

    NASA Astrophysics Data System (ADS)

    Sartore, Luciana; Pandini, Stefano; Baldi, Francesco; Bignotti, Fabio

    2016-05-01

    In this research work, biocomposites based on crosslinked particles of poly(acrylic acid), commonly used as superabsorbent polymer (SAP), and poly-L-lactic acid (PLLA) were developed to elucidate the role of the filler (i.e., polymeric crosslinked particles) on the overall physico-mechanical behavior and to obtain superabsorbent thermoplastic products. Samples prepared by melt-blending of components in different ratios showed a biphasic system with a regular distribution of particles, with diameter ranging from 5 to 10 μm, within the PLLA polymeric matrix. The polymeric biphasic system, coded PLASA i.e. superabsorbent poly(lactic acid), showed excellent swelling properties, demonstrating that cross-linked particles retain their superabsorbent ability, as in their free counterparts, even if distributed in a thermoplastic polymeric matrix. The thermal characteristics of the biocomposites evidence enhanced thermal stability in comparison with neat PLLA and also mechanical properties are markedly modified by addition of crosslinked particles which induce regular stiffening effect. Furthermore, in aqueous environments the particles swell and are leached from PLLA matrix generating very high porosity. These new open-pore PLLA foams, produced in absence of organic solvents and chemical foaming agents, with good physico-mechanical properties appear very promising for several applications, for instance in tissue engineering for scaffold production.

  16. General analytical procedure for determination of acidity parameters of weak acids and bases.

    PubMed

    Pilarski, Bogusław; Kaliszan, Roman; Wyrzykowski, Dariusz; Młodzianowski, Janusz; Balińska, Agata

    2015-01-01

    The paper presents a new convenient, inexpensive, and reagent-saving general methodology for the determination of pK a values for components of the mixture of diverse chemical classes weak organic acids and bases in water solution, without the need to separate individual analytes. The data obtained from simple pH-metric microtitrations are numerically processed into reliable pK a values for each component of the mixture. Excellent agreement has been obtained between the determined pK a values and the reference literature data for compounds studied.

  17. Influence of lactic acid bacteria on redox status and on proteolytic activity of buckwheat (Fagopyrum esculentum Moench) sourdoughs.

    PubMed

    Capuani, Alessandro; Behr, Jürgen; Vogel, Rudi F

    2013-07-15

    Redox potential and proteolysis determine protein networks in doughs and thus dough rheology as well as the structure of baked goods. Namely, gluten-free bakery products needs structural improvements but little is known about these parameters in gluten free dough systems. In this work the influence of lactic acid bacteria (LAB) on redox status and proteolysis of buckwheat sourdoughs was investigated. An increase of free thiol groups was detected as redox potential was decreasing during fermentation. Thiol content at 8 h was higher in doughs fermented with strains with high reductive activity, such as Weissella (W.) cibaria in comparison to Pediococcus (P.) pentosaceus, which exhibited a lower reducing activity. At 24 h each fermentation showed a similar content of free thiol groups. Endogenous buckwheat proteases were characterized using various protease inhibitors in buckwheat doughs. Until pH3.1 a proteolysis increase was monitored in doughs. Employed LAB didn't show any detectable extracellular proteolytic activity. Flour proteases are thus responsible for protein breakdown, and this was demonstrated comparing free amino nitrogen (FAN) values and protein electrophoretic patterns of sourdough fermentations with chemical acidified (CA) doughs. FAN content at 24 h using P. pentosaceus, proteolytic comparative strain of Enterococcus faecalis, W. cibaria, mixed culture (containing P. pentosaceus and W. cibaria), CA and CA doughs containing glutathione (GSH) reached 45.9±1.3, 42.4±1.3, 40±1, 31±2, 29±2 and 17.8±3.9 mmol kg(-1) flour, respectively. Proteolysis was mainly influenced by pH and incubation time. The addition of GSH showed a decrease of proteolysis and of free amino acids. CA doughs showed a higher total free amino acids content than sourdough fermented with LAB indicating their metabolization. Fermentations with high FAN values exhibited lower band intensity (analyzed under reducing condition) in electrophoretic patterns. These results show that

  18. Potential of a simple HPLC-based approach for the identification of the spoilage status of minced beef stored at various temperatures and packaging systems.

    PubMed

    Argyri, Anthoula A; Doulgeraki, Agapi I; Blana, Vasiliki A; Panagou, Efstathios Z; Nychas, George-John E

    2011-10-17

    The shelf life of minced beef stored (i) aerobically, (ii) under modified atmosphere packaging (MAP), and (iii) under MAP with oregano essential oil (MAP/OEO) at 0, 5, 10, and 15°C was investigated. The microbial association of meat and the temporal biochemical changes were monitored. Microbiological analyses, including total viable counts (TVC), Pseudomonas spp., Brochothrix thermosphacta, lactic acid bacteria, Enterobacteriaceae, and yeasts/moulds, were undertaken, in parallel with sensory assessment, pH measurement and HPLC analysis of the organic acid profiles. Spectral data collected by HPLC were subjected to statistical analysis, including principal component analysis (PCA) and factorial discriminant analysis (FDA). This revealed qualitative discrimination of the samples based on their spoilage status. Partial least squares regression (PLS-R) was used to evaluate quantitative predictions of TVC, Pseudomonas spp., Br. thermosphacta, lactic acid bacteria, Enterobacteriaceae, and yeasts/moulds. Overall, the HPLC analysis of organic acids, was found to be a potential method to evaluate the spoilage and microbial status of a meat sample regardless of the storage conditions. This could be a very useful tool for monitoring the quality of meat batches during transportation and storage in the meat food chain. PMID:21835483

  19. Analytic calculation of physiological acid-base parameters in plasma.

    PubMed

    Wooten, E W

    1999-01-01

    Analytic expressions for plasma total titratable base, base excess (DeltaCB), strong-ion difference, change in strong-ion difference (DeltaSID), change in Van Slyke standard bicarbonate (DeltaVSSB), anion gap, and change in anion gap are derived as a function of pH, total buffer ion concentration, and conditional molar equilibrium constants. The behavior of these various parameters under respiratory and metabolic acid-base disturbances for constant and variable buffer ion concentrations is considered. For constant noncarbonate buffer concentrations, DeltaSID = DeltaCB = DeltaVSSB, whereas these equalities no longer hold under changes in noncarbonate buffer concentration. The equivalence is restored if the reference state is changed to include the new buffer concentrations.

  20. Functional nucleic-acid-based sensors for environmental monitoring.

    PubMed

    Sett, Arghya; Das, Suradip; Bora, Utpal

    2014-10-01

    Efforts to replace conventional chromatographic methods for environmental monitoring with cheaper and easy to use biosensors for precise detection and estimation of hazardous environmental toxicants, water or air borne pathogens as well as various other chemicals and biologics are gaining momentum. Out of the various types of biosensors classified according to their bio-recognition principle, nucleic-acid-based sensors have shown high potential in terms of cost, sensitivity, and specificity. The discovery of catalytic activities of RNA (ribozymes) and DNA (DNAzymes) which could be triggered by divalent metallic ions paved the way for their extensive use in detection of heavy metal contaminants in environment. This was followed with the invention of small oligonucleotide sequences called aptamers which can fold into specific 3D conformation under suitable conditions after binding to target molecules. Due to their high affinity, specificity, reusability, stability, and non-immunogenicity to vast array of targets like small and macromolecules from organic, inorganic, and biological origin, they can often be exploited as sensors in industrial waste management, pollution control, and environmental toxicology. Further, rational combination of the catalytic activity of DNAzymes and RNAzymes along with the sequence-specific binding ability of aptamers have given rise to the most advanced form of functional nucleic-acid-based sensors called aptazymes. Functional nucleic-acid-based sensors (FNASs) can be conjugated with fluorescent molecules, metallic nanoparticles, or quantum dots to aid in rapid detection of a variety of target molecules by target-induced structure switch (TISS) mode. Although intensive research is being carried out for further improvements of FNAs as sensors, challenges remain in integrating such bio-recognition element with advanced transduction platform to enable its use as a networked analytical system for tailor made analysis of environmental

  1. Omega-3 Fatty Acid Status Enhances the Prevention of Cognitive Decline by B Vitamins in Mild Cognitive Impairment

    PubMed Central

    Oulhaj, Abderrahim; Jernerén, Fredrik; Refsum, Helga; Smith, A. David; de Jager, Celeste A.

    2016-01-01

    A randomized trial (VITACOG) in people with mild cognitive impairment (MCI) found that B vitamin treatment to lower homocysteine slowed the rate of cognitive and clinical decline. We have used data from this trial to see whether baseline omega-3 fatty acid status interacts with the effects of B vitamin treatment. 266 participants with MCI aged ≥70 years were randomized to B vitamins (folic acid, vitamins B6 and B12) or placebo for 2 years. Baseline cognitive test performance, clinical dementia rating (CDR) scale, and plasma concentrations of total homocysteine, total docosahexaenoic and eicosapentaenoic acids (omega-3 fatty acids) were measured. Final scores for verbal delayed recall, global cognition, and CDR sum-of-boxes were better in the B vitamin-treated group according to increasing baseline concentrations of omega-3 fatty acids, whereas scores in the placebo group were similar across these concentrations. Among those with good omega-3 status, 33% of those on B vitamin treatment had global CDR scores >0 compared with 59% among those on placebo. For all three outcome measures, higher concentrations of docosahexaenoic acid alone significantly enhanced the cognitive effects of B vitamins, while eicosapentaenoic acid appeared less effective. When omega-3 fatty acid concentrations are low, B vitamin treatment has no effect on cognitive decline in MCI, but when omega-3 levels are in the upper normal range, B vitamins interact to slow cognitive decline. A clinical trial of B vitamins combined with omega-3 fatty acids is needed to see whether it is possible to slow the conversion from MCI to AD. PMID:26757190

  2. Liquid crystal based biosensors for bile acid detection

    NASA Astrophysics Data System (ADS)

    He, Sihui; Liang, Wenlang; Tanner, Colleen; Fang, Jiyu; Wu, Shin-Tson

    2013-03-01

    The concentration level of bile acids is a useful indicator for early diagnosis of liver diseases. The prevalent measurement method in detecting bile acids is the chromatography coupled with mass spectrometry, which is precise yet expensive. Here we present a biosensor platform based on liquid crystal (LC) films for the detection of cholic acid (CA). This platform has the advantage of low cost, label-free, solution phase detection and simple analysis. In this platform, LC film of 4-Cyano-4'-pentylbiphenyl (5CB) was hosted by a copper grid supported with a polyimide-coated glass substrate. By immersing into sodium dodecyl sulfate (SDS) solution, the LC film was coated with SDS which induced a homeotropic anchoring of 5CB. Addition of CA introduced competitive adsorption between CA and SDS at the interface, triggering a transition from homeotropic to homogeneous anchoring. The detection limit can be tuned by changing the pH value of the solution from 12uM to 170uM.

  3. Paediatric acid-base disorders: A case-based review of procedures and pitfalls.

    PubMed

    Carmody, J Bryan; Norwood, Victoria F

    2013-01-01

    Acid-base disorders occur frequently in paediatric patients. Despite the perception that their analysis is complex and difficult, a straightforward set of rules is sufficient to interpret even the most complex disorders - provided certain pitfalls are avoided. Using a case-based approach, the present article reviews the fundamental concepts of acid-base analysis and highlights common mistakes and oversights. Specific topics include the proper identification of the primary disorder; distinguishing compensatory changes from additional primary disorders; use of the albumin-corrected anion gap to generate a differential diagnosis for patients with metabolic acidosis; screening for mixed disorders with the delta-delta formula; recognizing the limits of compensation; use of the anion gap to identify 'hidden' acidosis; and the importance of using information from the history and physical examination to identify the specific cause of a patient's acid-base disturbance.

  4. The comprehensive acid-base characterization of glutathione

    NASA Astrophysics Data System (ADS)

    Mirzahosseini, Arash; Somlyay, Máté; Noszál, Béla

    2015-02-01

    Glutathione in its thiol (GSH) and disulfide (GSSG) forms, and 4 related compounds were studied by 1H NMR-pH titrations and a case-tailored evaluation method. The resulting acid-base properties are quantified in terms of 128 microscopic protonation constants; the first complete set of such parameters for this vitally important pair of compounds. The concomitant 12 interactivity parameters were also determined. Since biological redox systems are regularly compared to the GSH-GSSG pair, the eight microscopic thiolate basicities determined this way are exclusive means for assessing subtle redox parameters in a wide pH range.

  5. Conducting Polymer Based Nucleic Acid Sensor for Environment Monitoring

    NASA Astrophysics Data System (ADS)

    Malhotra, Bansi Dhar; Prabhakar, Nirmal; Solanki, Pratima R.

    Nucleic acid sensor based on polyaniline has been fabricated by covalently immobilizing double stranded calf thymus (dsCT) DNA onto perchlorate (ClO-4) doped polyaniline (PANI) film deposited onto indium-tin-oxide (ITO) glass plate using 1-(3-(dimethylamino) propyl)-3-ethylcarbodiimide hydrochloride (EDC)/N-hydroxyl succinimide (NHS) chemistry. These dsCT-DNA-PANI/ITO and PANI/ITO electrodes have been characterized using square wave voltammetry, electrochemical impedance, and Fourier-transform-infra-red (FTIR) measurements. This disposable dsCT-DNA-PANI/ITO bioelectrode is stable for about four months, can be used to detect arsenic trioxide (0.1ppm) in 30s.

  6. Gallic acid-based indanone derivatives as anticancer agents.

    PubMed

    Saxena, Hari Om; Faridi, Uzma; Srivastava, Suchita; Kumar, J K; Darokar, M P; Luqman, Suaib; Chanotiya, C S; Krishna, Vinay; Negi, Arvind S; Khanuja, S P S

    2008-07-15

    Gallic acid-based indanone derivatives have been synthesised. Some of the indanones showed very good anticancer activity in MTT assay. Compounds 10, 11, 12 and 14 possessed potent anticancer activity against various human cancer cell lines. The most potent indanone (10, IC(50)=2.2 microM), against MCF-7, that is, hormone-dependent breast cancer cell line, showed no toxicity to human erythrocytes even at higher concentrations (100 microg/ml, 258 microM). While, indanones 11, 12 and 14 showed toxicities to erythrocytes at higher concentrations.

  7. Acid-Base Homeostasis: Overview for Infusion Nurses.

    PubMed

    Masco, Natalie A

    2016-01-01

    Acid-base homeostasis is essential to normal function of the human body. Even slight alterations can significantly alter physiologic processes at the tissue and cellular levels. To optimally care for patients, nurses must be able to recognize signs and symptoms that indicate deviations from normal. Nurses who provide infusions to patients-whether in acute care, home care, or infusion center settings-have a responsibility to be able to recognize the laboratory value changes that occur with the imbalance and appreciate the treatment options, including intravenous infusions. PMID:27598068

  8. A fully automatic system for acid-base coulometric titrations.

    PubMed

    Cladera, A; Caro, A; Estela, J M; Cerdà, V

    1990-01-01

    An automatic system for acid-base titrations by electrogeneration of H(+) and OH(-) ions, with potentiometric end-point detection, was developed. The system includes a PC-compatible computer for instrumental control, data acquisition and processing, which allows up to 13 samples to be analysed sequentially with no human intervention.The system performance was tested on the titration of standard solutions, which it carried out with low errors and RSD. It was subsequently applied to the analysis of various samples of environmental and nutritional interest, specifically waters, soft drinks and wines.

  9. [Acid-base equilibrium in sportsmen during physical exercise].

    PubMed

    Brinzak, V P; Kalinskiĭ, M I; Val'tin, A I; Povzhitkova, M S

    1983-01-01

    Acid-base balance in venous blood of basketball players was studied under specific loadings of various intensity by means of the micro-Astrup device. It is established that under acyclic loadings (throwing the ball into the basket) the state of metabolic acidosis is developed in the sportsmen and the more intensive the work, the higher the degree of the state of metabolic acidosis. The efficiency of actions of the persons examined was in inverse dependence on the degree of metabolic disturbances, i.e. the least efficiency was marked under the most profound acidosis.

  10. Comparison of (6 S)-5-methyltetrahydrofolic acid v. folic acid as the reference folate in longer-term human dietary intervention studies assessing the relative bioavailability of natural food folates: comparative changes in folate status following a 16-week placebo-controlled study in healthy adults.

    PubMed

    Wright, Anthony J A; King, Maria J; Wolfe, Caroline A; Powers, Hilary J; Finglas, Paul M

    2010-03-01

    Folic acid (pteroylmonoglutamic acid) has historically been used as the reference folate in human intervention studies assessing the relative bioavailability of dietary folate. Recent studies using labelled folates indicated different plasma response kinetics to folic acid than to natural (food) folates, thus obviously precluding its use in single-dose experiments. Since differences in tissue distribution and site of biotransformation were hypothesised, the question is whether folic acid remains suitable as a reference folate for longer-term intervention studies, where the relative bioavailability of natural (food) folate is assessed based on changes in folate status. Healthy adults aged 18-65 years (n 163) completed a 16-week placebo-controlled intervention study in which the relative bioavailability of increased folate intake (453 nmol/d) from folate-rich foods was assessed by comparing changes in plasma and erythrocyte folate concentration with changes induced by an equal reference dose of supplemental (6S)-5-methyltetrahydrofolic acid or folic acid. The relative increase in plasma folate concentration in the food group was 31 % when compared with that induced by folic acid, but 39 % when compared with (6S)-5-methyltetrahydrofolic acid. The relative increase in erythrocyte folate concentration in the food group when compared with that induced by folic acid was 43 %, and 40 % when compared with (6S)-5-methyltetrahydrofolic acid. When recent published observations were additionally taken into account it was concluded that, in principle, folic acid should not be used as the reference folate when attempting to estimate relative natural (food) folate bioavailability in longer-term human intervention studies. Using (6S)-5-methyltetrahydrofolic acid as the reference folate would avoid future results' validity being questioned.

  11. Effects of dietary pantothenic acid on growth, intestinal function, anti-oxidative status and fatty acids synthesis of juvenile blunt snout bream Megalobrama amblycephala.

    PubMed

    Qian, Yu; Li, Xiang-Fei; Zhang, Ding-Dong; Cai, Dong-Sen; Tian, Hong-Yan; Liu, Wen-Bin

    2015-01-01

    Four groups of juvenile Megalobrama amblycephala were fed three times daily with six semi-purified diets containing 3.39 (PA unsupplied diet), 10.54, 19.28, 31.04, 48.38 and 59.72 mg kg(-1) calcium D-pantothenate. The results showed that survival rate, final weight, specific growth rate, protein efficiency ratio and nitrogen retention efficiency all increased significantly (P<0.01) as dietary PA levels increased from 3.39 to 19.28 mg kg(-1), whereas the opposite was true for feed conversion ratio. Whole-body crude protein increased as dietary PA levels increased, while the opposite pattern was found for the crude lipid content. Intestinal α-amylase, lipase, protease, Na+-K+-ATPase, alkaline phosphatase and gamma-glutamyl transferase activities were all elevated in fish fed PA-supplemented diets. Hepatic catalase activities improved with increases in dietary PA, while the opposite was true for malondialdehyde contents. The liver PA concentration and coenzyme A content rose significantly (P<0.01), up to 31.04 mg kg(-1), with increasing dietary PA levels and then plateaued. The percentage of hepatic saturated fatty acids increased significantly (P<0.01) as dietary PA levels increased, while the percentages of monounsaturated fatty acids and polyunsaturated fatty acid (PUFA) decreased as dietary PA increased. Fish fed diets containing 19.28 and 31.04 mg kg(-1) PA exhibited higher (P<0.01) docosahexaenoic acid and PUFA percentages in muscle than those fed with other diets. The expression of the gene encoding pantothenate kinase was significantly up-regulated (P<0.01) in fish fed PA-supplemented diets. Hepatic Acetyl-CoA carboxylase α, fatty acid synthetase, stearoyl regulatory element-binding protein 1 and X receptor α genes all increased significantly (P<0.01) as dietary PA levels increased from 3.39 to 31.04 mg kg(-1). Based on broken-line regression analyses of weight gain, liver CoA concentrations and PA contents against dietary PA levels, the optimal dietary PA

  12. Effects of Dietary Pantothenic Acid on Growth, Intestinal Function, Anti-Oxidative Status and Fatty Acids Synthesis of Juvenile Blunt Snout Bream Megalobrama amblycephala

    PubMed Central

    Qian, Yu; Li, Xiang-Fei; Zhang, Ding-Dong; Cai, Dong-Sen; Tian, Hong-Yan; Liu, Wen-Bin

    2015-01-01

    Four groups of juvenile Megalobrama amblycephala were fed three times daily with six semi-purified diets containing 3.39 (PA unsupplied diet), 10.54, 19.28, 31.04, 48.38 and 59.72 mg kg-1 calcium D-pantothenate. The results showed that survival rate, final weight, specific growth rate, protein efficiency ratio and nitrogen retention efficiency all increased significantly (P<0.01) as dietary PA levels increased from 3.39 to 19.28 mg kg-1, whereas the opposite was true for feed conversion ratio. Whole-body crude protein increased as dietary PA levels increased, while the opposite pattern was found for the crude lipid content. Intestinal α-amylase, lipase, protease, Na+-K+-ATPase, alkaline phosphatase and gamma-glutamyl transferase activities were all elevated in fish fed PA-supplemented diets. Hepatic catalase activities improved with increases in dietary PA, while the opposite was true for malondialdehyde contents. The liver PA concentration and coenzyme A content rose significantly (P<0.01), up to 31.04 mg kg-1, with increasing dietary PA levels and then plateaued. The percentage of hepatic saturated fatty acids increased significantly (P<0.01) as dietary PA levels increased, while the percentages of monounsaturated fatty acids and polyunsaturated fatty acid (PUFA) decreased as dietary PA increased. Fish fed diets containing 19.28 and 31.04 mg kg-1 PA exhibited higher (P<0.01) docosahexaenoic acid and PUFA percentages in muscle than those fed with other diets. The expression of the gene encoding pantothenate kinase was significantly up-regulated (P<0.01) in fish fed PA-supplemented diets. Hepatic Acetyl-CoA carboxylase α, fatty acid synthetase, stearoyl regulatory element-binding protein 1 and X receptor α genes all increased significantly (P<0.01) as dietary PA levels increased from 3.39 to 31.04 mg kg-1. Based on broken-line regression analyses of weight gain, liver CoA concentrations and PA contents against dietary PA levels, the optimal dietary PA

  13. 78 FR 36698 - Microbiology Devices; Reclassification of Nucleic Acid-Based Systems for Mycobacterium tuberculosis

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-19

    ... Nucleic Acid-Based Systems for Mycobacterium tuberculosis Complex in Respiratory Specimens AGENCY: Food...) is proposing to reclassify nucleic acid-based in vitro diagnostic devices for the detection of... Controls Guideline: Nucleic Acid-Based In Vitro Diagnostic Devices for the Detection of...

  14. Oral nutritional supplements containing (n-3) polyunsaturated fatty acids affect the nutritional status of patients with stage III non-small cell lung cancer during multimodality treatment.

    PubMed

    van der Meij, Barbara S; Langius, Jacqueline A E; Smit, Egbert F; Spreeuwenberg, Marieke D; von Blomberg, B Mary E; Heijboer, Annemieke C; Paul, Marinus A; van Leeuwen, Paul A M

    2010-10-01

    Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), (n-3) fatty acids from fish oil, have immune-modulating effects and may improve nutritional status in cancer. The objective of this study was to investigate the effects of an oral nutritional supplement containing (n-3) fatty acids on nutritional status and inflammatory markers in patients with non-small cell lung cancer (NSCLC) undergoing multimodality treatment. In a double-blind experiment, 40 patients with stage III NSCLC were randomly assigned to receive 2 cans/d of a protein- and energy-dense oral nutritional supplement containing (n-3) fatty acids (2.0 g EPA + 0.9 g DHA/d) or an isocaloric control supplement. EPA in plasma phospholipids, energy intake, resting energy expenditure (REE), body weight, fat free mass (FFM), mid-upper arm circumference (MUAC), and inflammatory markers were assessed. Effects of intervention were analyzed by generalized estimating equations and expressed as regression coefficients (B). The intervention group (I) had a better weight maintenance than the control (C) group after 2 and 4 wk (B = 1.3 and 1.7 kg, respectively; P < 0.05), a better FFM maintenance after 3 and 5 wk (B = 1.5 and 1.9 kg, respectively; P < 0.05), a reduced REE (B = -16.7% of predicted; P = 0.01) after 3 wk, and a trend for a greater MUAC (B = 9.1; P = 0.06) and lower interleukin-6 production (B = -27.9; P = 0.08) after 5 wk. After 4 wk, the I group had a higher energy and protein intake than the C group (B = 2456 kJ/24 h, P = 0.03 and B = 25.0 g, P = 0.01, respectively). In conclusion, a protein- and energy-dense oral nutritional supplement containing (n-3) fatty acids beneficially affects nutritional status during multimodality treatment in patients with NSCLC.

  15. Environmental Status Assessment Using DNA Metabarcoding: Towards a Genetics Based Marine Biotic Index (gAMBI)

    PubMed Central

    Aylagas, Eva; Borja, Ángel; Rodríguez-Ezpeleta, Naiara

    2014-01-01

    Marine ecosystem protection and conservation initiatives rely on the assessment of ecological integrity and health status of marine environments. The AZTI's Marine Biotic Index (AMBI), which consists on using macroinvertebrate diversity as indicator of ecosystem health, is used worldwide for this purpose. Yet, this index requires taxonomic assignment of specimens, which typically involves a time and resource consuming visual identification of each sample. DNA barcoding or metabarcoding are potential harmonized, faster and cheaper alternatives for species identification, although the suitability of these methods for easing the implementation of the AMBI is yet to be evaluated. Here, we analyze the requirements for the implementation of a genetics based AMBI (gAMBI), and show, using available sequence data, that information about presence/absence of the most frequently occurring species provides accurate AMBI values. Our results set the basics for the implementation of the gAMBI, which has direct implications for a faster and cheaper marine monitoring and health status assessment. PMID:24603433

  16. Environmental status assessment using DNA metabarcoding: towards a genetics based Marine Biotic Index (gAMBI).

    PubMed

    Aylagas, Eva; Borja, Angel; Rodríguez-Ezpeleta, Naiara

    2014-01-01

    Marine ecosystem protection and conservation initiatives rely on the assessment of ecological integrity and health status of marine environments. The AZTI's Marine Biotic Index (AMBI), which consists on using macroinvertebrate diversity as indicator of ecosystem health, is used worldwide for this purpose. Yet, this index requires taxonomic assignment of specimens, which typically involves a time and resource consuming visual identification of each sample. DNA barcoding or metabarcoding are potential harmonized, faster and cheaper alternatives for species identification, although the suitability of these methods for easing the implementation of the AMBI is yet to be evaluated. Here, we analyze the requirements for the implementation of a genetics based AMBI (gAMBI), and show, using available sequence data, that information about presence/absence of the most frequently occurring species provides accurate AMBI values. Our results set the basics for the implementation of the gAMBI, which has direct implications for a faster and cheaper marine monitoring and health status assessment.

  17. Migration and health: exploring the role of migrant status through register-based studies.

    PubMed

    Nørredam, Marie

    2015-04-01

    This thesis aims to explore migrant status as a determinant in register-based studies on migrant health. It is based on eight studies that investigate the following three main issues: 1) What is the importance of migrant status for morbidity patterns among migrants compared with Native Danes? 2) Do migrant status and ethnicity affect clinical indicators of access among migrants compared with native Danes? 3) What is the importance of migrant status for mortality patterns among migrants compared with Native Danes? The thesis builds on a register-based historical prospective cohort design. Through Statistics Denmark, all refugees (n = 29,174) and family reunification immigrants (n = 33,287) who received residence permits in Denmark from 1 January 1993 to 31 December 1999 were included and matched 4:1 on age and sex with Native Danes. Register linkage was obtained twice during follow-ups in 2004 and 2008 respectively. Personal identification numbers were cross-linked to the Danish Psychiatric Central Register, the National Patient Registry, the Registry of Coercive Measures in Psychiatric Treatment, the Register of Causes of Death, and the Danish Cancer Registry. Migrant status defined by legal grounds for obtaining a residence permit was dichotomised into refugees and family reunification immigrants and used as the determinant in most studies. Analyses involved both Poisson and Cox regression analysis. Most analyses were stratified by ethnicity and adjusted for age and sex. Some were also stratified for individual income. Three sub-themes were investigated: morbidity, clinical indicators of access, and mortality. The first sub-theme (Papers I-III) showed that refugees had a consistently higher morbidity from several mental health disorders in contrast to family reunification immigrants, whose morbidity from mental disorders was lower than or similar to native Danes. The cancer incidence study did not find an effect of migrant status but found, rather, that migrants

  18. [Mental status and work capacity of crewmen at the Salute-6 space flight base].

    PubMed

    Miasnikov, V I

    1983-01-01

    The psychic status and work capacity of prime crewmembers of missions 1 and 5 onboard Salyut-6 were investigated, using objective (scope, time and quality of the work performed) and subjective (fatigue, mood variation, complaints) parameters. Based on these parameters, it was possible to identify several stages in the dynamics of the psychic status and work capacity: stage of acute adaptation, stage of complete compensation (2-3 or 4 months), stage of incomplete compensation (3 or 4-5 months), and stage of final "breakaway" (last month). These stages reflect the process of psychic and professional adaptation to space flight. The process of adaptation is strongly affected by the rational work-rest cycle, in which the sleep period coincides with that associated with Moscow time, and events of psychological support. The results show that crewmembers may well adapt and work in space flight for a long time.

  19. Effect of temperature on the acid-base properties of the alumina surface: microcalorimetry and acid-base titration experiments.

    PubMed

    Morel, Jean-Pierre; Marmier, Nicolas; Hurel, Charlotte; Morel-Desrosiers, Nicole

    2006-06-15

    Sorption reactions on natural or synthetic materials that can attenuate the migration of pollutants in the geosphere could be affected by temperature variations. Nevertheless, most of the theoretical models describing sorption reactions are at 25 degrees C. To check these models at different temperatures, experimental data such as the enthalpies of sorption are thus required. Highly sensitive microcalorimeters can now be used to determine the heat effects accompanying the sorption of radionuclides on oxide-water interfaces, but enthalpies of sorption cannot be extracted from microcalorimetric data without a clear knowledge of the thermodynamics of protonation and deprotonation of the oxide surface. However, the values reported in the literature show large discrepancies and one must conclude that, amazingly, this fundamental problem of proton binding is not yet resolved. We have thus undertaken to measure by titration microcalorimetry the heat effects accompanying proton exchange at the alumina-water interface at 25 degrees C. Based on (i) the surface sites speciation provided by a surface complexation model (built from acid-base titrations at 25 degrees C) and (ii) results of the microcalorimetric experiments, calculations have been made to extract the enthalpic variations associated respectively to first and second deprotonation of the alumina surface. Values obtained are deltaH1 = 80+/-10 kJ mol(-1) and deltaH2 = 5+/-3 kJ mol(-1). In a second step, these enthalpy values were used to calculate the alumina surface acidity constants at 50 degrees C via the van't Hoff equation. Then a theoretical titration curve at 50 degrees C was calculated and compared to the experimental alumina surface titration curve. Good agreement between the predicted acid-base titration curve and the experimental one was observed.

  20. Design of chitosan-based nanoparticles functionalized with gallic acid.

    PubMed

    Lamarra, J; Rivero, S; Pinotti, A

    2016-10-01

    Active nanoparticles based on chitosan could be applied as a support for the modulation of gallic acid delivery. In this sense, these nanostructures could be employed in different fields such as food, packaging, and pharmaceutical areas. The design parameters of chitosan-based nanoparticles functionalized with gallic acid (GA) were optimized through RSM by means of the analysis of zeta potential (ZP) and percentage encapsulation efficiency (PEE). The nanoparticles were prepared by ionotropic gelation using tripolyphosphate (TPP), at different combinations of chitosan (CH) concentration, CH:TPP ratio and GA. Global desirability methodology allowed finding the optimum formulation that included CH 0.76% (w/w), CH:TPP ratio of 5 and 37mgGA/gCH leading to ZP of +50mV and 82% of PEE. Analysis through QuickScan and turbidity demonstrated that the most stable nanoparticle suspensions were achieved combining concentrations of chitosan ranging between 0.5 and 0.75% with CH:TPP ratios higher than 3. These suspensions had high stability confirmed by means ZP and transmittance values which were higher than +25mV and 0.21 on average, respectively, as well as nanoparticle diameters of about 140nm. FTIR revealed the occurrence of both hydrogen bond and ionic interactions of CH-TPP which allowed the encapsulation and the improvement of the stability of the active agent. PMID:27287172

  1. Sphingoid bases inhibit acid-induced demineralization of hydroxyapatite.

    PubMed

    Valentijn-Benz, Marianne; van 't Hof, Wim; Bikker, Floris J; Nazmi, Kamran; Brand, Henk S; Sotres, Javier; Lindh, Liselott; Arnebrant, Thomas; Veerman, Enno C I

    2015-01-01

    Calcium hydroxyapatite (HAp), the main constituent of dental enamel, is inherently susceptible to the etching and dissolving action of acids, resulting in tooth decay such as dental caries and dental erosion. Since the prevalence of erosive wear is gradually increasing, there is urgent need for agents that protect the enamel against erosive attacks. In the present study we studied in vitro the anti-erosive effects of a number of sphingolipids and sphingoid bases, which form the backbone of sphingolipids. Pretreatment of HAp discs with sphingosine, phytosphingosine (PHS), PHS phosphate and sphinganine significantly protected these against acid-induced demineralization by 80 ± 17%, 78 ± 17%, 78 ± 7% and 81 ± 8%, respectively (p < 0.001). On the other hand, sphingomyelin, acetyl PHS, octanoyl PHS and stearoyl PHS had no anti-erosive effects. Atomic force measurement revealed that HAp discs treated with PHS were almost completely and homogeneously covered by patches of PHS. This suggests that PHS and other sphingoid bases form layers on the surface of HAp, which act as diffusion barriers against H(+) ions. In principle, these anti-erosive properties make PHS and related sphingosines promising and attractive candidates as ingredients in oral care products.

  2. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials.

    PubMed

    Wu, Peiwen; Yu, Yang; McGhee, Claire E; Tan, Li Huey; Lu, Yi

    2014-12-10

    In this review, we summarize recent progress in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insights gained from these studies are described and future directions of this field are also discussed.

  3. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

    PubMed Central

    Wu, Peiwen; Yu, Yang; McGhee, Claire E.; Tan, Li Huey

    2014-01-01

    In this review, we summarize recent progresses in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insights gained from these studies are described and future directions of this field are also discussed. PMID:25205057

  4. Short-term supplementation of low-dose gamma-linolenic acid (GLA), alpha-linolenic acid (ALA), or GLA plus ALA does not augment LCP omega 3 status of Dutch vegans to an appreciable extent.

    PubMed

    Fokkema, M R; Brouwer, D A; Hasperhoven, M B; Martini, I A; Muskiet, F A

    2000-11-01

    Vegans do not consume meat and fish and have therefore low intakes of long chain polyunsaturated fatty acids (LCP). They may consequently have little negative feedback inhibition from dietary LCP on conversion of alpha -linolenic acid (ALA) to the LCP omega 3 eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. We investigated whether supplementation of nine apparently healthy vegans with 2.01 g ALA (4 ml linseed oil), 1.17 g gamma-linolenic acid (GLA) (6 ml borage oil) or their combination increases the LCP omega 3 contents of erythrocytes (RBC) and platelets (PLT), and of plasma phospholipids (PL), cholesterol esters (CE) and triglycerides (TG). The supplements changed the dietary LA/ALA ratio (in g/g) from about 13.7 (baseline) to 6.8 (linseed oil), 14.3 (borage oil) and 6.4 (linseed + borage oil), respectively. ALA or GLA given as single supplements did not increase LCP omega 3 status, but their combination augmented LCP omega 3 (in CE) and EPA (in fasting TG) to a statistically significant, but nevertheless negligible, extent. We conclude that negative feedback inhibition by dietary LCP, if any, does not play an important role in the inability to augment notably DHA status by dietary ALA. The reach of a DHA plateau already at low dietary ALA intakes suggests that dietary DHA causes a non-functional DHA surplus, or is, alternatively, important for maintaining DHA status at a functionally relevant level. PMID:11090255

  5. Nutritional status assessment in semiclosed environments: ground-based and space flight studies in humans

    NASA Technical Reports Server (NTRS)

    Smith, S. M.; Davis-Street, J. E.; Rice, B. L.; Nillen, J. L.; Gillman, P. L.; Block, G.

    2001-01-01

    Adequate nutrition is critical during long-term spaceflight, as is the ability to easily monitor dietary intake. A comprehensive nutritional status assessment profile was designed for use before, during and after flight. It included assessment of both dietary intake and biochemical markers of nutritional status. A spaceflight food-frequency questionnaire (FFQ) was developed to evaluate intake of key nutrients during spaceflight. The nutritional status assessment protocol was evaluated during two ground-based closed-chamber studies (60 and 91 d; n = 4/study), and was implemented for two astronauts during 4-mo stays on the Mir space station. Ground-based studies indicated that the FFQ, administered daily or weekly, adequately estimated intake of key nutrients. Chamber subjects maintained prechamber energy intake and body weight. Astronauts tended to eat 40--50% of WHO-predicted energy requirements, and lost >10% of preflight body mass. Serum ferritin levels were lower after the chamber stays, despite adequate iron intake. Red blood cell folate concentrations were increased after the chamber studies. Vitamin D stores were decreased by > 40% on chamber egress and after spaceflight. Mir crew members had decreased levels of most nutritional indices, but these are difficult to interpret given the insufficient energy intake and loss of body mass. Spaceflight food systems can provide adequate intake of macronutrients, although, as expected, micronutrient intake is a concern for any closed or semiclosed food system. These data demonstrate the utility and importance of nutritional status assessment during spaceflight and of the FFQ during extended-duration spaceflight.

  6. Transcriptome analysis of the hippocampal CA1 pyramidal cell region after kainic acid-induced status epilepticus in juvenile rats.

    PubMed

    Laurén, Hanna B; Lopez-Picon, Francisco R; Brandt, Annika M; Rios-Rojas, Clarissa J; Holopainen, Irma E

    2010-01-01

    Molecular mechanisms involved in epileptogenesis in the developing brain remain poorly understood. The gene array approach could reveal some of the factors involved by allowing the identification of a broad scale of genes altered by seizures. In this study we used microarray analysis to reveal the gene expression profile of the laser microdissected hippocampal CA1 subregion one week after kainic acid (KA)-induced status epilepticus (SE) in 21-day-old rats, which are developmentally roughly comparable to juvenile children. The gene expression analysis with the Chipster software generated a total of 1592 differently expressed genes in the CA1 subregion of KA-treated rats compared to control rats. The KEGG database revealed that the identified genes were involved in pathways such as oxidative phosporylation (26 genes changed), and long-term potentiation (LTP; 18 genes changed). Also genes involved in Ca(2+) homeostasis, gliosis, inflammation, and GABAergic transmission were altered. To validate the microarray results we further examined the protein expression for a subset of selected genes, glial fibrillary protein (GFAP), apolipoprotein E (apo E), cannabinoid type 1 receptor (CB1), Purkinje cell protein 4 (PEP-19), and interleukin 8 receptor (CXCR1), with immunohistochemistry, which confirmed the transcriptome results. Our results showed that SE resulted in no obvious CA1 neuronal loss, and alterations in the expression pattern of several genes during the early epileptogenic phase were comparable to previous gene expression studies of the adult hippocampus of both experimental epileptic animals and patients with temporal lobe epilepsy (TLE). However, some changes seem to occur after SE specifically in the juvenile rat hippocampus. Insight of the SE-induced alterations in gene expression and their related pathways could give us hints for the development of new target-specific antiepileptic drugs that interfere with the progression of the disease in the juvenile age

  7. A comprehensive classification of nucleic acid structural families based on strand direction and base pairing.

    PubMed Central

    Lavery, R; Zakrzewska, K; Sun, J S; Harvey, S C

    1992-01-01

    We propose a classification of DNA structures formed from 1 to 4 strands, based only on relative strand directions, base to strand orientation and base pairing geometries. This classification and its associated notation enable all nucleic acids to be grouped into structural families and bring to light possible structures which have not yet been observed experimentally. It also helps in understanding transitions between families and can assist in the design of multistrand structures. PMID:1383936

  8. Probe kit for identifying a base in a nucleic acid

    DOEpatents

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2001-01-01

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  9. Hybridization and sequencing of nucleic acids using base pair mismatches

    DOEpatents

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2001-01-01

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  10. Method of Identifying a Base in a Nucleic Acid

    DOEpatents

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    1999-01-01

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  11. Fatty Acid Blood Levels, Vitamin D Status, Physical Performance, Activity, and Resiliency: A Novel Potential Screening Tool for Depressed Mood in Active Duty Soldiers.

    PubMed

    Barringer, Nicholas D; Kotwal, Russ S; Lewis, Michael D; Funderburk, Leslee K; Elliott, Timothy R; Crouse, Stephen F; Smith, Stephen B; Greenwood, Michael; Kreider, Richard B

    2016-09-01

    This study examined whether blood fatty acid levels, vitamin D status, and/or physical activity are associated with physical fitness scores; a measure of mood, Patient Health Questionnaire-9; and a measure of resiliency, Dispositional Resiliency Scale-15 in active duty Soldiers. 100 active duty males at Fort Hood, Texas, underwent a battery of psychometric tests, anthropometric measurements, and fitness tests, and they also provided fasting blood samples for fatty acid and vitamin D analysis. Pearson bivariate correlation analysis revealed significant correlations among psychometric tests, anthropometric measurements, physical performance, reported physical inactivity (sitting time), and fatty acid and vitamin D blood levels. On the basis of these findings, a regression equation was developed to predict a depressed mood status as determined by the Patient Health Questionnaire-9. The equation accurately predicted depressed mood status in 80% of our participants with a sensitivity of 76.9% and a specificity of 80.5%. Results indicate that the use of a regression equation may be helpful in identifying Soldiers at higher risk for mental health issues. Future studies should evaluate the impact of exercise and diet as a means of improving resiliency and reducing depressed mood in Soldiers. PMID:27612362

  12. 5 CFR 875.208 - May I apply as a qualified relative if the person on whom I am basing my eligibility status has...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the person on whom I am basing my eligibility status has died? 875.208 Section 875.208 Administrative... I am basing my eligibility status has died? You may not apply as a qualified relative if the workforce member on whom you are basing your qualified relative status died prior to the time you apply...

  13. 5 CFR 875.208 - May I apply as a qualified relative if the person on whom I am basing my eligibility status has...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the person on whom I am basing my eligibility status has died? 875.208 Section 875.208 Administrative... I am basing my eligibility status has died? You may not apply as a qualified relative if the workforce member on whom you are basing your qualified relative status died prior to the time you apply...

  14. 5 CFR 875.208 - May I apply as a qualified relative if the person on whom I am basing my eligibility status has...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the person on whom I am basing my eligibility status has died? 875.208 Section 875.208 Administrative... I am basing my eligibility status has died? You may not apply as a qualified relative if the workforce member on whom you are basing your qualified relative status died prior to the time you apply...

  15. 5 CFR 875.208 - May I apply as a qualified relative if the person on whom I am basing my eligibility status has...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... the person on whom I am basing my eligibility status has died? 875.208 Section 875.208 Administrative... I am basing my eligibility status has died? You may not apply as a qualified relative if the workforce member on whom you are basing your qualified relative status died prior to the time you apply...

  16. Acid-base titrations using microfluidic paper-based analytical devices.

    PubMed

    Karita, Shingo; Kaneta, Takashi

    2014-12-16

    Rapid and simple acid-base titration was accomplished using a novel microfluidic paper-based analytical device (μPAD). The μPAD was fabricated by wax printing and consisted of ten reservoirs for reaction and detection. The reaction reservoirs contained various amounts of a primary standard substance, potassium hydrogen phthalate (KHPth), whereas a constant amount of phenolphthalein was added to all the detection reservoirs. A sample solution containing NaOH was dropped onto the center of the μPAD and was allowed to spread to the reaction reservoirs where the KHPth neutralized it. When the amount of NaOH exceeded that of the KHPth in the reaction reservoirs, unneutralized hydroxide ion penetrated the detection reservoirs, resulting in a color reaction from the phenolphthalein. Therefore, the number of the detection reservoirs with no color change determined the concentration of the NaOH in the sample solution. The titration was completed within 1 min by visually determining the end point, which required neither instrumentation nor software. The volumes of the KHPth and phenolphthalein solutions added to the corresponding reservoirs were optimized to obtain reproducible and accurate results for the concentration of NaOH. The μPADs determined the concentration of NaOH at orders of magnitude ranging from 0.01 to 1 M. An acid sample, HCl, was also determined using Na2CO3 as a primary standard substance instead of KHPth. Furthermore, the μPAD was applicable to the titrations of nitric acid, sulfuric acid, acetic acid, and ammonia solutions. The μPADs were stable for more than 1 month when stored in darkness at room temperature, although this was reduced to only 5 days under daylight conditions. The analysis of acidic hot spring water was also demonstrated in the field using the μPAD, and the results agreed well with those obtained by classic acid-base titration.

  17. Guanine base stacking in G-quadruplex nucleic acids.

    PubMed

    Lech, Christopher Jacques; Heddi, Brahim; Phan, Anh Tuân

    2013-02-01

    G-quadruplexes constitute a class of nucleic acid structures defined by stacked guanine tetrads (or G-tetrads) with guanine bases from neighboring tetrads stacking with one another within the G-tetrad core. Individual G-quadruplexes can also stack with one another at their G-tetrad interface leading to higher-order structures as observed in telomeric repeat-containing DNA and RNA. In this study, we investigate how guanine base stacking influences the stability of G-quadruplexes and their stacked higher-order structures. A structural survey of the Protein Data Bank is conducted to characterize experimentally observed guanine base stacking geometries within the core of G-quadruplexes and at the interface between stacked G-quadruplex structures. We couple this survey with a systematic computational examination of stacked G-tetrad energy landscapes using quantum mechanical computations. Energy calculations of stacked G-tetrads reveal large energy differences of up to 12 kcal/mol between experimentally observed geometries at the interface of stacked G-quadruplexes. Energy landscapes are also computed using an AMBER molecular mechanics description of stacking energy and are shown to agree quite well with quantum mechanical calculated landscapes. Molecular dynamics simulations provide a structural explanation for the experimentally observed preference of parallel G-quadruplexes to stack in a 5'-5' manner based on different accessible tetrad stacking modes at the stacking interfaces of 5'-5' and 3'-3' stacked G-quadruplexes. PMID:23268444

  18. Structure of six organic acid-base adducts from 6-bromobenzo[d]thiazol-2-amine and acidic compounds

    NASA Astrophysics Data System (ADS)

    Jin, Shouwen; Zhang, Jing; Wang, Daqi; Tao, Lin; Zhou, Mengjian; Shen, Yinyan; Chen, Quan; Lin, Zhanghui; Gao, Xingjun

    2014-05-01

    Six anhydrous organic acid-base adducts of 6-bromobenzo[d]thiazol-2-amine were prepared with organic acids as 2,4,6-trinitrophenol, salicylic acid, 3,5-dinitrobenzoic acid, 3,5-dinitrosalicylic acid, malonic acid and sebacic acid. The compounds 1-6 were characterized by X-ray diffraction analysis, IR, and elemental analysis. The melting points of all the adducts were given. Of the six adducts, 1, 3, 4, and 5 are organic salts, while 2, and 6 are cocrystals. The supramolecular arrangement in the crystals 2-6 is based on the R22(8) synthon. Analysis of the crystal packing of 1-6 suggests that there are strong NH⋯O, OH⋯N, and OH⋯O hydrogen bonds (charge assisted or neutral) between acid and base components in the supramolecular assemblies. When the hydroxyl group is present in the ortho position of the carboxy, the intramolecular S6 synthon is present, as expected. Besides the classical hydrogen bonding interactions, other noncovalent interactions also play important roles in structure extension. Due to the synergetic effect of these weak interactions, compounds 1-6 display 1D-3D framework structure.

  19. Trophic status of the Iranian Caspian Sea based on water quality parameters and phytoplankton diversity

    NASA Astrophysics Data System (ADS)

    Nasrollahzadeh, Hasan Saravi; Din, Zubir Bin; Foong, Swee Yeok; Makhlough, Asieh

    2008-05-01

    The present study attempted to test the applicability of the trophic index (TRIX) for assessing trophic status along the Iranian coast of the Caspian Sea (CS). In order to increase the sensitivity of the TRIX for this area, we defined the range (lower and upper limits) from data collected between 1994 and 2005 which have been used as a reference. Several biological and chemical water quality parameters were determined and compared with the TRIX in order to describe the water quality status of the area. Comparisons were also made on two temporarily and spatially varied trophic status at the study site. Sampling was carried out at 36 stations during Phase I (1996-1997: before the introduction of an alien species Mnemiopsis leidyi, as a background data) while 24 stations were sampled during Phase II in 2005 (after the introduction of the alien species). A Parallel Study (as supplementary data) from 16 smaller scale sampling at shallower sites was also included in the discussion (1994-2005 on 18 transects). The results show that nutrient concentration (DIN, DIP compounds), oxygen (as absolute %) deviation from saturation (aD%O), chlorophyll a and also the Caspian Sea Trophic Index (TRIXCS) increase significantly after the introduction of an alien species ( p<0.01). During Phase I and the Parallel Study, the phytoplankton community was dominated (based on important species index) by Thalassionema nitzschioides, Skeletonema costatum (Chrysophyta) year round but during Phase II, Spirulina laxissma (Cyanophyta ) dominated annually and in autumn, coinciding with the minimum Shannon-Weaver diversity and Evenness indices recorded. Several trophic status indices and indicators were applied and an overall analysis suggested that the area has low trophic level during Phase I and high trophic level during Phase II. During the Parallel Study, low trophic level was recorded during the pre-invasion period and high trophic level for the post-invasion period.

  20. Folic acid supplemented goat milk has beneficial effects on hepatic physiology, haematological status and antioxidant defence during chronic Fe repletion.

    PubMed

    Alférez, María J M; Rivas, Emilio; Díaz-Castro, Javier; Hijano, Silvia; Nestares, Teresa; Moreno, Miguel; Campos, Margarita S; Serrano-Reina, Jose A; López-Aliaga, Inmaculada

    2015-02-01

    The aim of the current study was to asses the effect of goat or cow milk-based diets, either normal or Fe-overloaded and folic acid supplement on some aspects of hepatic physiology, enzymatic antioxidant defence and lipid peroxidation in liver, brain and erythrocyte of control and anaemic rats after chronic Fe repletion. 160 male Wistar rats were placed on 40 d in two groups, a control group receiving normal-Fe diet and the Fe-deficient group receiving low Fe diet. Lately, the rats were fed with goat and cow milk-based diets during 30 d, with normal-Fe content or Fe-overload and either with normal folic or folic acid supplemented. Fe-overload increased plasma alanine transaminase and aspartate transaminase levels when cow milk was supplied. Dietary folate supplementation reduced plasma transaminases levels in animals fed goat milk with chronic Fe overload. A remarkable increase in the superoxide dismutase activity was observed in the animals fed cow milk. Dietary folate supplement lead to a decrease on the activity of this enzyme in all the tissues studied with both milk-based diets. A concomitant increment in catalase was also observed. The increase in lipid peroxidation products levels in rats fed cow milk with Fe-overload, suggest an imbalance in the functioning of the enzymatic antioxidant defence. In conclusion, dietary folate-supplemented goat milk reduces both plasma transaminases levels, suggesting a hepatoprotective effect and has beneficial effects in situation of Fe-overload, improving the antioxidant enzymes activities and reducing lipid peroxidation.

  1. Folic acid supplemented goat milk has beneficial effects on hepatic physiology, haematological status and antioxidant defence during chronic Fe repletion.

    PubMed

    Alférez, María J M; Rivas, Emilio; Díaz-Castro, Javier; Hijano, Silvia; Nestares, Teresa; Moreno, Miguel; Campos, Margarita S; Serrano-Reina, Jose A; López-Aliaga, Inmaculada

    2015-02-01

    The aim of the current study was to asses the effect of goat or cow milk-based diets, either normal or Fe-overloaded and folic acid supplement on some aspects of hepatic physiology, enzymatic antioxidant defence and lipid peroxidation in liver, brain and erythrocyte of control and anaemic rats after chronic Fe repletion. 160 male Wistar rats were placed on 40 d in two groups, a control group receiving normal-Fe diet and the Fe-deficient group receiving low Fe diet. Lately, the rats were fed with goat and cow milk-based diets during 30 d, with normal-Fe content or Fe-overload and either with normal folic or folic acid supplemented. Fe-overload increased plasma alanine transaminase and aspartate transaminase levels when cow milk was supplied. Dietary folate supplementation reduced plasma transaminases levels in animals fed goat milk with chronic Fe overload. A remarkable increase in the superoxide dismutase activity was observed in the animals fed cow milk. Dietary folate supplement lead to a decrease on the activity of this enzyme in all the tissues studied with both milk-based diets. A concomitant increment in catalase was also observed. The increase in lipid peroxidation products levels in rats fed cow milk with Fe-overload, suggest an imbalance in the functioning of the enzymatic antioxidant defence. In conclusion, dietary folate-supplemented goat milk reduces both plasma transaminases levels, suggesting a hepatoprotective effect and has beneficial effects in situation of Fe-overload, improving the antioxidant enzymes activities and reducing lipid peroxidation. PMID:25394837

  2. Acid-degradable polyurethane particles for protein-based vaccines

    PubMed Central

    Bachelder, Eric M.; Beaudette, Tristan T.; Broaders, Kyle E.; Paramonov, Sergey E.; Dashe, Jesse; Fréchet, Jean M. J.

    2009-01-01

    Acid-degradable particles containing a model protein antigen, ovalbumin, were prepared from a polyurethane with acetal moieties embedded throughout the polymer, and characterized by dynamic light scattering and transmission electron microscopy. The small molecule degradation by-product of the particles was synthesized and tested in vitro for toxicity indicating an LC50 of 12,500 μg/ml. A new liquid chromatography-mass spectrometry technique was developed to monitor the in vitro degradation of these particles. The degradation by-product inside RAW macrophages was at its highest level after 24 hours of culture and was efficiently exocytosed until it was no longer detectable after four days. When tested in vitro, these particles induced a substantial increase in the presentation of the immunodominant ovalbumin-derived peptide SIINFEKL in both macrophages and dendritic cells. In addition, vaccination with these particles generated a cytotoxic T-lymphocyte response that was superior to both free ovalbumin and particles made from an analogous but slower-degrading acid-labile polyurethane polymer. Overall, we present a fully degradable polymer system with non-toxic by-products, which may find use in various biomedical applications including protein-based vaccines. PMID:18710254

  3. Kinetics of acid base catalyzed transesterification of Jatropha curcas oil.

    PubMed

    Jain, Siddharth; Sharma, M P

    2010-10-01

    Out of various non-edible oil resources, Jatropha curcas oil (JCO) is considered as future feedstock for biodiesel production in India. Limited work is reported on the kinetics of transesterification of high free fatty acids containing oil. The present study reports the results of kinetic study of two-step acid base catalyzed transesterification process carried out at an optimum temperature of 65 °C and 50 °C for esterification and transesterification respectively under the optimum methanol to oil ratio of 3:7 (v/v), catalyst concentration 1% (w/w) for H₂SO₄ and NaOH. The yield of methyl ester (ME) has been used to study the effect of different parameters. The results indicate that both esterification and transesterification reaction are of first order with reaction rate constant of 0.0031 min⁻¹ and 0.008 min⁻¹ respectively. The maximum yield of 21.2% of ME during esterification and 90.1% from transesterification of pretreated JCO has been obtained.

  4. Water-wire catalysis in photoinduced acid-base reactions.

    PubMed

    Kwon, Oh-Hoon; Mohammed, Omar F

    2012-07-01

    The pronounced ability of water to form a hyperdense hydrogen (H)-bond network among itself is at the heart of its exceptional properties. Due to the unique H-bonding capability and amphoteric nature, water is not only a passive medium, but also behaves as an active participant in many chemical and biological reactions. Here, we reveal the catalytic role of a short water wire, composed of two (or three) water molecules, in model aqueous acid-base reactions synthesizing 7-hydroxyquinoline derivatives. Utilizing femtosecond-resolved fluorescence spectroscopy, we tracked the trajectories of excited-state proton transfer and discovered that proton hopping along the water wire accomplishes the reaction more efficiently compared to the transfer occurring with bulk water clusters. Our finding suggests that the directionality of the proton movements along the charge-gradient H-bond network may be a key element for long-distance proton translocation in biological systems, as the H-bond networks wiring acidic and basic sites distal to each other can provide a shortcut for a proton in searching a global minimum on a complex energy landscape to its destination.

  5. Fast high-throughput method for the determination of acidity constants by capillary electrophoresis: I. Monoprotic weak acids and bases.

    PubMed

    Fuguet, Elisabet; Ràfols, Clara; Bosch, Elisabeth; Rosés, Martí

    2009-04-24

    A new and fast method to determine acidity constants of monoprotic weak acids and bases by capillary zone electrophoresis based on the use of an internal standard (compound of similar nature and acidity constant as the analyte) has been developed. This method requires only two electrophoretic runs for the determination of an acidity constant: a first one at a pH where both analyte and internal standard are totally ionized, and a second one at another pH where both are partially ionized. Furthermore, the method is not pH dependent, so an accurate measure of the pH of the buffer solutions is not needed. The acidity constants of several phenols and amines have been measured using internal standards of known pK(a), obtaining a mean deviation of 0.05 pH units compared to the literature values. PMID:19168179

  6. Fast high-throughput method for the determination of acidity constants by capillary electrophoresis: I. Monoprotic weak acids and bases.

    PubMed

    Fuguet, Elisabet; Ràfols, Clara; Bosch, Elisabeth; Rosés, Martí

    2009-04-24

    A new and fast method to determine acidity constants of monoprotic weak acids and bases by capillary zone electrophoresis based on the use of an internal standard (compound of similar nature and acidity constant as the analyte) has been developed. This method requires only two electrophoretic runs for the determination of an acidity constant: a first one at a pH where both analyte and internal standard are totally ionized, and a second one at another pH where both are partially ionized. Furthermore, the method is not pH dependent, so an accurate measure of the pH of the buffer solutions is not needed. The acidity constants of several phenols and amines have been measured using internal standards of known pK(a), obtaining a mean deviation of 0.05 pH units compared to the literature values.

  7. Estimation of soil moisture status based on TVDI and ATI in Heihe River basin

    NASA Astrophysics Data System (ADS)

    Lin, C.; Zhou, S.; Huang, Y.; LV, E.; Zheng, Y.

    2015-12-01

    Based on TVDI (Temperature-Vegetation Dryness Index) and ATI (Apparent Thermal Inertia), this study estimated the soil moisture status in Heihe river basin (northwestern of China) using the vegetation, surface temperature and surface reflectance products in 2012 from MODIS. When calculating the dry edge and wet edge in temperature-vegetation triangle framework, a step-width of 0.02 in NDVI was set and the maximum and minimum temperatures in each interval were found. A fitting line was derived based on these points using the least square method. The results shows that the values of R2 of the dry edge is larger than that of the wet edge. The average R2 of dry edges is 0.89, while the average R2 of wet edges in only 0.74. The slope of dry edges reaches its peak absolute value of -61.51 in DOY 97 (day of year) in 2012. To divide the whole basin into different parts with different degrees of soil moisture status, defined intervals and natural breaks methods were used for TVDI and ATI respectively. The majority of the upstream of Heihe river is comparable or general wet region, with the downstream of the river basin being the dry region. The result of TVDI shows that the midstream of the river belongs to the dry region, as same as its surrounding areas. However, the result of ATI shows the midstream of the river is much wetter. The comparison between the in-situ precipitation data and TVDI and ATI indicates that TVDI and ATI both respond to the precipitation. Only the remote sensing data is need to estimate the soil moisture status based on the TVDI and ATI methods, which can provide straightforward approaches to estimate soil moisture and monitor drought.

  8. Spherical Nucleic Acids as Intracellular Agents for Nucleic Acid Based Therapeutics

    NASA Astrophysics Data System (ADS)

    Hao, Liangliang

    Recent functional discoveries on the noncoding sequences of human genome and transcriptome could lead to revolutionary treatment modalities because the noncoding RNAs (ncRNAs) can be applied as therapeutic agents to manipulate disease-causing genes. To date few nucleic acid-based therapeutics have been translated into the clinic due to challenges in the delivery of the oligonucleotide agents in an effective, cell specific, and non-toxic fashion. Unmodified oligonucleotide agents are destroyed rapidly in biological fluids by enzymatic degradation and have difficulty crossing the plasma membrane without the aid of transfection reagents, which often cause inflammatory, cytotoxic, or immunogenic side effects. Spherical nucleic acids (SNAs), nanoparticles consisting of densely organized and highly oriented oligonucleotides, pose one possible solution to circumventing these problems in both the antisense and RNA interference (RNAi) pathways. The unique three dimensional architecture of SNAs protects the bioactive oligonucleotides from unspecific degradation during delivery and supports their targeting of class A scavenger receptors and endocytosis via a lipid-raft-dependent, caveolae-mediated pathway. Owing to their unique structure, SNAs are able to cross cell membranes and regulate target genes expression as a single entity, without triggering the cellular innate immune response. Herein, my thesis has focused on understanding the interactions between SNAs and cellular components and developing SNA-based nanostructures to improve therapeutic capabilities. Specifically, I developed a novel SNA-based, nanoscale agent for delivery of therapeutic oligonucleotides to manipulate microRNAs (miRNAs), the endogenous post-transcriptional gene regulators. I investigated the role of SNAs involving miRNAs in anti-cancer or anti-inflammation responses in cells and in in vivo murine disease models via systemic injection. Furthermore, I explored using different strategies to construct

  9. Modeling description and spectroscopic evidence of surface acid-base properties of natural illites.

    PubMed

    Liu, W

    2001-12-01

    The acid-base properties of natural illites from different areas were studied by potentiometric titrations. The acidimetric supernatant was regarded as the system blank to calculate the surface site concentration due to consideration of substrate dissolution during the prolonged acidic titration. The following surface complexation model could give a good interpretation of the surface acid-base reactions of the aqueous illites:

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  11. Buoyancy-driven instabilities of acid-base fronts

    NASA Astrophysics Data System (ADS)

    Almarcha, Christophe; R'honi, Yasmina; Trevelyan, Philip M. J.; de Wit, Anne

    2010-11-01

    Chemical reactions can produce buoyancy-driven motions in solutions by changing the local density in the gravity field. Starting from a stratification of one given miscible reactant solution on top of another miscible one, convective destabilization influenced by the reaction can emerge as a combination of several non-reactive hydrodynamic instabilities, including Rayleigh-Taylor and double diffusive instabilities. In the specific case of reactions between a strong acid and a strong base, we show that all the possible scenarios reduce to the composition of only two asymptotic situations because products generated at the reactive zone are always less dense and slower diffusing than the reactants. Experiments in a vertically orientated Hele-Shaw cell confirm the theoretical predictions and can be quantitatively compared to numerical simulations of a nonlinear reaction-diffusion-convection model.

  12. Ultrasonic and densimetric titration applied for acid-base reactions.

    PubMed

    Burakowski, Andrzej; Gliński, Jacek

    2014-01-01

    Classical acoustic acid-base titration was monitored using sound speed and density measurements. Plots of these parameters, as well as of the adiabatic compressibility coefficient calculated from them, exhibit changes with the volume of added titrant. Compressibility changes can be explained and quantitatively predicted theoretically in terms of Pasynski theory of non-compressible hydrates combined with that of the additivity of the hydration numbers with the amount and type of ions and molecules present in solution. It also seems that this development could be applied in chemical engineering for monitoring the course of chemical processes, since the applied experimental methods can be carried out almost independently on the medium under test (harmful, aggressive, etc.).

  13. The protective effect of myo-inositol on hippocamal cell loss and structural alterations in neurons and synapses triggered by kainic acid-induced status epilepticus.

    PubMed

    Kotaria, Nato; Kiladze, Maia; Zhvania, Mzia G; Japaridze, Nadezhda J; Bikashvili, Tamar; Solomonia, Revaz O; Bolkvadze, Tamar

    2013-07-01

    It is known that myo-inositol pretreatment attenuates the seizure severity and several biochemical changes provoked by experimentally induced status epilepticus. However, it remains unidentified whether such properties of myo-inositol influence the structure of epileptic brain. In the present light and electron microscopic research we elucidate if pretreatment with myo-inositol has positive effect on hippocampal cell loss, and cell and synapses damage provoked by kainic acid-induced status epilepticus. Adult male Wistar rats were treated with (i) saline, (ii) saline + kainic acid, (iii) myo-inositol + kainic acid. Assessment of cell loss at 2, 14, and 30 days after treatment demonstrate cytoprotective effect of myo-inositol in CA1 and CA3 areas. It was strongly expressed in pyramidal layer of CA1, radial and oriental layers of CA3 and in less degree-in other layers of both fields. Ultrastructural alterations were described in CA1, 14 days after treatment. The structure of neurons, synapses, and porosomes are well preserved in the rats pretreated with myo-inositol in comparing with rats treated with only kainic acid.

  14. Rice protein-based infant formula: current status and future development.

    PubMed

    Koo, W W K; Lasekan, J B

    2007-02-01

    Rice is the world's leading staple cereal food and is the major source of protein for many parts of the world. Rice is among the first solid foods fed to infants in many cultures, in part because of its hypoallergenicity from lack of gluten. Nutritional quality of rice protein compares favorably with other cereal proteins including wheat, oat and barley. It is rich in methionine and cystine, although as is the case for other cereals, it is an incomplete protein source for human infants with lysine and threonine being the primary limiting amino acids. Fortification of rice proteins with these two limiting amino acids improves its protein quality. Rice protein-based infant formulas (RPF) were initially based on high protein rice flours, but more recently are based on rice protein concentrates, isolates or hydrolysates, fortified with lysine and threonine. Hypoallergenicity efficacy, particularly for hydrolyzed rice protein-based formulas, has been reported, and limited data indicated that rice protein based infant formula may provide potentially adequate alternative if standard milk- or soy protein-based formulas are not tolerated. Unlike the rice-protein based infant formula, rice beverage formulas made from rice flour are nutritionally inadequate for infants. Reports have indicated stunted growth in infants/children fed rice beverage formulas. Future development for the RPF include those based on genetically improved rice with high lysine and threonine content, supplementation with appropriate mineral and fat blend, and long-term clinical studies in infants to confirm its efficacy and safety.

  15. CLUSTERING SOUTH AFRICAN HOUSEHOLDS BASED ON THEIR ASSET STATUS USING LATENT VARIABLE MODELS

    PubMed Central

    McParland, Damien; Gormley, Isobel Claire; McCormick, Tyler H.; Clark, Samuel J.; Kabudula, Chodziwadziwa Whiteson; Collinson, Mark A.

    2014-01-01

    The Agincourt Health and Demographic Surveillance System has since 2001 conducted a biannual household asset survey in order to quantify household socio-economic status (SES) in a rural population living in northeast South Africa. The survey contains binary, ordinal and nominal items. In the absence of income or expenditure data, the SES landscape in the study population is explored and described by clustering the households into homogeneous groups based on their asset status. A model-based approach to clustering the Agincourt households, based on latent variable models, is proposed. In the case of modeling binary or ordinal items, item response theory models are employed. For nominal survey items, a factor analysis model, similar in nature to a multinomial probit model, is used. Both model types have an underlying latent variable structure—this similarity is exploited and the models are combined to produce a hybrid model capable of handling mixed data types. Further, a mixture of the hybrid models is considered to provide clustering capabilities within the context of mixed binary, ordinal and nominal response data. The proposed model is termed a mixture of factor analyzers for mixed data (MFA-MD). The MFA-MD model is applied to the survey data to cluster the Agincourt households into homogeneous groups. The model is estimated within the Bayesian paradigm, using a Markov chain Monte Carlo algorithm. Intuitive groupings result, providing insight to the different socio-economic strata within the Agincourt region. PMID:25485026

  16. Adansonian Analysis and Deoxyribonucleic Acid Base Composition of Serratia marcescens

    PubMed Central

    Colwell, R. R.; Mandel, M.

    1965-01-01

    Colwell, R. R. (Georgetown University, Washington, D.C.), and M. Mandel. Adansonian analysis and deoxyribonucleic acid base composition of Serratia marcescens. J. Bacteriol. 89:454–461. 1965.—A total of 33 strains of Serratia marcescens were subjected to Adansonian analysis for which more than 200 coded features for each of the organisms were included. In addition, the base composition [expressed as moles per cent guanine + cytosine (G + C)] of the deoxyribonucleic acid (DNA) prepared from each of the strains was determined. Except for four strains which were intermediate between Serratia and the Hafnia and Aerobacter group C of Edwards and Ewing, the S. marcescens species group proved to be extremely homogeneous, and the different strains showed high affinities for each other (mean similarity, ¯S = 77%). The G + C ratio of the DNA from the Serratia strains ranged from 56.2 to 58.4% G + C. Many species names have been listed for the genus, but only a single clustering of the strains was obtained at the species level, for which the species name S. marcescens was retained. S. kiliensis, S. indica, S. plymuthica, and S. marinorubra could not be distinguished from S. marcescens; it was concluded, therefore, that there is only a single species in the genus. The variety designation kiliensis does not appear to be valid, since no subspecies clustering of strains with negative Voges-Proskauer reactions could be detected. The characteristics of the species are listed, and a description of S. marcescens is presented. PMID:14255714

  17. Are carboxyl groups the most acidic sites in amino acids? Gas-phase acidities, photoelectron spectra, and computations on tyrosine, p-hydroxybenzoic acid, and their conjugate bases.

    PubMed

    Tian, Zhixin; Wang, Xue-Bin; Wang, Lai-Sheng; Kass, Steven R

    2009-01-28

    Deprotonation of tyrosine in the gas phase was found to occur preferentially at the phenolic site, and the conjugate base consists of a 70:30 mixture of phenoxide and carboxylate anions at equilibrium. This result was established by developing a chemical probe for differentiating these two isomers, and the presence of both ions was confirmed by photoelectron spectroscopy. Equilibrium acidity measurements on tyrosine indicated that deltaG(acid)(o) = 332.5 +/- 1.5 kcal mol(-1) and deltaH(acid)(o) = 340.7 +/- 1.5 kcal mol(-1). Photoelectron spectra yielded adiabatic electron detachment energies of 2.70 +/- 0.05 and 3.55 +/- 0.10 eV for the phenoxide and carboxylate anions, respectively. The H/D exchange behavior of deprotonated tyrosine was examined using three different alcohols (CF3CH2OD, C6H5CH2OD, and CH3CH2OD), and incorporation of up to three deuterium atoms was observed. Two pathways are proposed to account for these results, and all of the experimental findings are supplemented with B3LYP/aug-cc-pVDZ and G3B3 calculations. In addition, it was found that electrospray ionization of tyrosine from a 3:1 (v/v) CH3OH/H2O solution using a commercial source produces a deprotonated [M-H]- anion with the gas-phase equilibrium composition rather than the structure of the ion that exists in aqueous media. Electrospray ionization from acetonitrile, however, leads largely to the liquid-phase (carboxylate) structure. A control molecule, p-hydroxybenzoic acid, was found to behave in a similar manner. Thus, the electrospray conditions that are employed for the analysis of a compound can alter the isomeric composition of the resulting anion.

  18. Nanoconstructions Based on Spatially Ordered Nucleic Acid Molecules

    NASA Astrophysics Data System (ADS)

    Yevdokimov, Yu. M.

    Different strategies for the design of nanoconstructions whose building blocks are both linear molecules of double-stranded nucleic acids and nucleic acid molecules fixed in the spatial structure of particles of liquid-crystalline dispersions are described.

  19. Amine-based systems for carboxylic acid recovery

    SciTech Connect

    King, C.J.

    1992-05-01

    Several carboxylic acids are prominent commercial products, and their number and importance will probably grow. Getting these acids out of aqueous solution is necessary in petrochemical manufacture, fermentation, and the environmentally and economically important recovery from waste streams. In this paper, the authors discuss the methods possible to extract acids such as citric, lactic, and succinic from complex mixtures. Carboxylic acids are also readily made by fermentation and are among the most attractive substances that could be manufactured from biomass. Branches of this cycle lead to acetic, lactic, propionic, and formic acids, among others. Carboxylic acids are promising intermediates in a bioprocessing complex, because the oxygen of the biomass is placed in a form that is useful for further reaction with many other products. Citric acid is manufactured on a large scale by fermentation, and lactic and fumaric acids, among others, were manufactured that way in the past.

  20. Microgel Tethering For Microarray-Based Nucleic Acid Diagnostics

    NASA Astrophysics Data System (ADS)

    Dai, Xiaoguang

    Molecular diagnostics (MDx) have radically changed the process of clinical microbial identification based on identifying genetic information, MDx approaches are both specific and fast. They can identify microbes to the species and strain level over a time scale that can be as short as one hour. With such information clinicians can administer the most effective and appropriate antimicrobial treatment at an early time point with substantial implications both for patient well-being and for easing the burden on the health-care system. Among the different MDx approaches, such as fluorescence in-situ hybridization, microarrays, next-generation sequencing, and mass spectrometry, point-of-care MDx platforms are drawing particular interest due to their low cost, robustness, and wide application. This dissertation develops a novel MDx technology platform capable of high target amplification and detection performance. For nucleic acid target detection, we fabricate an array of electron-beam-patterned microgels on a standard glass microscope slide. The microgels can be as small as a few hundred nanometers. The unique way of energy deposition during electron-beam lithography provides the microgels with a very diffuse water -gel interface that enables them to not only serve as substrates to immobilize DNA probes but do so while preserving them in a highly hydrated environment that optimizes their performance. Benefiting from the high spatial resolution provided by such techniques as position-sensitive microspotting and dip-pen nanolithography, multiple oligonucleotide probes known as molecular beacons (MBs) can be patterned on microgels. Furthermore, nucleic acid target amplification can be conducted in direct contact with the microgel-tethered detection array. Specifically, we use an isothermal RNA amplification reaction - nucleic acid sequence-based amplification (NASBA). ssRNA amplicons of from the NASBA reaction can directly hybridize with microgel-tethered MBs, and the

  1. Idiopathic recurrent calcium urolithiasis (IRCU): pathophysiology evaluated in light of oxidative metabolism, without and with variation of several biomarkers in fasting urine and plasma - a comparison of stone-free and -bearing male patients, emphasizing mineral, acid-base, blood pressure and protein status

    PubMed Central

    2011-01-01

    Background IRCU is traditionally considered as lifestyle disease (associations with, among others, overweight, obesity, hypertension, type-2 diabetes), arising from excess, in 24 h urine, of calcium (Ca) salts (calcium oxalate (CaOx), calcium phosphate (CaPi)), supersaturation of, and crystallization in, tubular fluid and urine, causing crystal-induced epithelial cell damage, proteinuria, crystal aggregation and uroliths. Methods Another picture emerges from the present uncontrolled study of 154 male adult IRCU patients (75 stone-bearing (SB) and 79 age-matched stone-free (SF)), in whom stone-forming and other parameters in fasting urine and plasma were contrasted with five biomarkers (see footnote) of oxidative metabolism (OM), without and with variation of markers. Results 1) In SB vs. SF unstratified OM biomarkers were statistically unchanged, but the majority of patients was overweight; despite, in SB vs. SF urine pH, total and non-albumin protein concentration were elevated, fractional urinary uric acid excretion and blood bicarbonate decreased, whereas urine volume, sodium, supersaturation with CaOx and CaPi (as hydroxyapatite) were unchanged; 2) upon variation of OM markers (strata below and above median) numerous stone parameters differed significant!)', among others urine volume, total protein, Ca/Pi ratio, pH, sodium, potassium, plasma Ca/Pi ratio and parathyroid hormone, blood pressure, renal excretion of non-albumin protein and other substances; 3) a significant shift from SF to SB patients occurred with increase of urine pH, decrease of blood bicarbonate, and increase of diastolic blood pressure, whereas increase of plasma uric acid impacted only marginally; 4) in both SF and SB patients a strong curvilinear relationship links a rise of urine Ca/Pi to urine Ca/Pi divided by plasma Ca/Pi, but in SB urine Ca/Pi failed to correlate significantly with urine hydroxyapatite supersaturation; 5) also in SB, plasma Ca/Pi and urinary nitrate were negatively

  2. Improved physical stability of amorphous state through acid base interactions.

    PubMed

    Telang, Chitra; Mujumdar, Siddharthya; Mathew, Michael

    2009-06-01

    To investigate role of specific interactions in aiding formation and stabilization of amorphous state in ternary and binary dispersions of a weakly acidic drug. Indomethacin (IMC), meglumine (MU), and polyvinyl pyrollidone (PVP) were the model drug, base, and polymer, respectively. Dispersions were prepared using solvent evaporation. Physical mixtures were cryogenically coground. XRPD, PLM, DSC, TGA, and FTIR were used for characterization. MU has a high crystallization tendency and is characterized by a low T(g) (17 degrees C). IMC crystallization was inhibited in ternary dispersion with MU compared to IMC/PVP alone. An amorphous state formed readily even in coground mixtures. Spectroscopic data are indicative of an IMC-MU amorphous salt and supports solid-state proton transfer. IMC-MU salt displays a low T(g) approximately 50 degrees C, but is more physically stable than IMC, which in molecular mixtures with MU, resisted crystallization even when present in stoichiometric excess of base. This is likely due to a disrupted local structure of amorphous IMC due to specific interactions. IMC showed improved physical stability on incorporating MU in polymer, in spite of low T(g) of the base indicating that chemical interactions play a dominant role in physical stabilization. Salt formation could be induced thermally and mechanically.

  3. Acid-base transport by the renal proximal tubule

    PubMed Central

    Skelton, Lara A.; Boron, Walter F.; Zhou, Yuehan

    2015-01-01

    Each day, the kidneys filter 180 L of blood plasma, equating to some 4,300 mmol of the major blood buffer, bicarbonate (HCO3−). The glomerular filtrate enters the lumen of the proximal tubule (PT), and the majority of filtered HCO3− is reclaimed along the early (S1) and convoluted (S2) portions of the PT in a manner coupled to the secretion of H+ into the lumen. The PT also uses the secreted H+ to titrate non-HCO3− buffers in the lumen, in the process creating “new HCO3−” for transport into the blood. Thus, the PT – along with more distal renal segments – is largely responsible for regulating plasma [HCO3−]. In this review we first focus on the milestone discoveries over the past 50+ years that define the mechanism and regulation of acid-base transport by the proximal tubule. Further on in the review, we will summarize research still in progress from our laboratory, work that addresses the problem of how the PT is able to finely adapt to acid–base disturbances by rapidly sensing changes in basolateral levels of HCO3− and CO2 (but not pH), and thereby to exert tight control over the acid–base composition of the blood plasma. PMID:21170887

  4. [Determination of body fluid based on analysis of nucleic acids].

    PubMed

    Korabečná, Marie

    2015-01-01

    Recent methodological approaches of molecular genetics allow isolation of nucleic acids (DNA and RNA) from negligible forensic samples. Analysis of these molecules may be used not only for individual identification based on DNA profiling but also for the detection of origin of the body fluid which (alone or in mixture with other body fluids) forms the examined biological trace. Such an examination can contribute to the evaluation of procedural, technical and tactical value of the trace. Molecular genetic approaches discussed in the review offer new possibilities in comparison with traditional spectrum of chemical, immunological and spectroscopic tests especially with regard to the interpretation of mixtures of biological fluids and to the confirmatory character of the tests. Approaches based on reverse transcription of tissue specific mRNA and their subsequent polymerase chain reaction (PCR) and fragmentation analysis are applicable on samples containing minimal amounts of biological material. Methods for body fluid discrimination based on examination of microRNA in samples provided so far confusing results therefore further development in this field is needed. The examination of tissue specific methylation of nucleotides in selected gene sequences seems to represent a promising enrichment of the methodological spectrum. The detection of DNA sequences of tissue related bacteria has been established and it provides satisfactory results mainly in combination with above mentioned methodological approaches. PMID:26419517

  5. Methylene-bis[(aminomethyl)phosphinic acids]: synthesis, acid-base and coordination properties.

    PubMed

    David, Tomáš; Procházková, Soňa; Havlíčková, Jana; Kotek, Jan; Kubíček, Vojtěch; Hermann, Petr; Lukeš, Ivan

    2013-02-21

    Three symmetrical methylene-bis[(aminomethyl)phosphinic acids] bearing different substituents on the central carbon atom, (NH(2)CH(2))PO(2)H-C(R(1))(R(2))-PO(2)H(CH(2)NH(2)) where R(1) = OH, R(2) = Me (H(2)L(1)), R(1) = OH, R(2) = Ph (H(2)L(2)) and R(1),R(2) = H (H(2)L(3)), were synthesized. Acid-base and complexing properties of the ligands were studied in solution as well as in the solid state. The ligands show unusually high basicity of the nitrogen atoms (log K(1) = 9.5-10, log K(2) = 8.5-9) if compared with simple (aminomethyl)phosphinic acids and, consequently, high stability constants of the complexes with studied divalent metal ions. The study showed the important role of the hydroxo group attached to the central carbon atom of the geminal bis(phosphinate) moiety. Deprotonation of the hydroxo group yields the alcoholate anion which tends to play the role of a bridging ligand and induces formation of polynuclear complexes. Solid-state structures of complexes [H(2)N=C(NH(2))(2)][Cu(2)(H(-1)L(2))(2)]CO(3)·10H(2)O and Li(2)[Co(4)(H(-1)L(1))(3)(OH)]·17.5H(2)O were determined by X-ray diffraction. The complexes show unexpected geometries forming dinuclear and cubane-like structures, respectively. The dinuclear copper(II) complex contains a bridging μ(2)-alcoholate group with the (-)O-P(=O)-CH(2)-NH(2) fragments of each ligand molecule chelated to the different central ion. In the cubane cobalt(II) complex, one μ(3)-hydroxide and three μ(3)-alcoholate anions are located in the cube vertices and both phosphinate groups of one ligand molecule are chelating the same cobalt(II) ion while each of its amino groups are bound to different neighbouring metal ions. All such three metal ions are bridged by the alcoholate group of a given ligand.

  6. Reaction Mechanism for Direct Proton Transfer from Carbonic Acid to a Strong Base in Aqueous Solution I: Acid and Base Coordinate and Charge Dynamics.

    PubMed

    Daschakraborty, Snehasis; Kiefer, Philip M; Miller, Yifat; Motro, Yair; Pines, Dina; Pines, Ehud; Hynes, James T

    2016-03-10

    Protonation by carbonic acid H2CO3 of the strong base methylamine CH3NH2 in a neutral contact pair in aqueous solution is followed via Car-Parrinello molecular dynamics simulations. Proton transfer (PT) occurs to form an aqueous solvent-stabilized contact ion pair within 100 fs, a fast time scale associated with the compression of the acid-base hydrogen-bond (H-bond), a key reaction coordinate. This rapid barrierless PT is consistent with the carbonic acid-protonated base pKa difference that considerably favors the PT, and supports the view of intact carbonic acid as potentially important proton donor in assorted biological and environmental contexts. The charge redistribution within the H-bonded complex during PT supports a Mulliken picture of charge transfer from the nitrogen base to carbonic acid without altering the transferring hydrogen's charge from approximately midway between that of a hydrogen atom and that of a proton. PMID:26879554

  7. Reaction Mechanism for Direct Proton Transfer from Carbonic Acid to a Strong Base in Aqueous Solution I: Acid and Base Coordinate and Charge Dynamics.

    PubMed

    Daschakraborty, Snehasis; Kiefer, Philip M; Miller, Yifat; Motro, Yair; Pines, Dina; Pines, Ehud; Hynes, James T

    2016-03-10

    Protonation by carbonic acid H2CO3 of the strong base methylamine CH3NH2 in a neutral contact pair in aqueous solution is followed via Car-Parrinello molecular dynamics simulations. Proton transfer (PT) occurs to form an aqueous solvent-stabilized contact ion pair within 100 fs, a fast time scale associated with the compression of the acid-base hydrogen-bond (H-bond), a key reaction coordinate. This rapid barrierless PT is consistent with the carbonic acid-protonated base pKa difference that considerably favors the PT, and supports the view of intact carbonic acid as potentially important proton donor in assorted biological and environmental contexts. The charge redistribution within the H-bonded complex during PT supports a Mulliken picture of charge transfer from the nitrogen base to carbonic acid without altering the transferring hydrogen's charge from approximately midway between that of a hydrogen atom and that of a proton.

  8. Amino acid-bile acid based molecules: extremely narrow surfactant nanotubes formed by a phenylalanine-substituted cholic acid.

    PubMed

    Travaglini, Leana; D'Annibale, Andrea; Schillén, Karin; Olsson, Ulf; Sennato, Simona; Pavel, Nicolae V; Galantini, Luciano

    2012-12-21

    An amino acid-substituted bile acid forms tubular aggregates with inner and outer diameters of about 3 and 6 nm. The diameters are unusually small for surfactant self-assembled tubes. The results enhance the spectrum of applications of supramolecular tubules and open up possibilities for investigating a novel class of biological amphiphiles.

  9. Genotype and fetal size affect maternal-fetal amino acid status and fetal endocrinology in Large White × Landrace and Meishan pigs.

    PubMed

    Ashworth, Cheryl J; Nwagwu, Margaret O; McArdle, Harry J

    2013-01-01

    This study compared maternal plasma amino acid concentrations, placental protein secretion in vitro and fetal body composition and plasma amino acid and hormone concentrations in feto-placental units from the smallest and a normally-sized fetus carried by Large White × Landrace or Meishan gilts on Day 100 of pregnancy. Compared with Large White × Landrace, Meishan placental tissue secreted more protein and Meishan fetuses contained relatively more fat and protein, but less moisture. Fetal plasma concentrations of insulin, triiodothryonine, thyroxine and insulin-like growth factor (IGF)-II were higher in Meishan than Large White × Landrace fetuses. In both breeds, fetal cortisol concentrations were inversely related to fetal size, whereas concentrations of IGF-I were higher in average-sized fetuses. Concentrations of 10 amino acids were higher in Large White × Landrace than Meishan gilts, while glutamine concentrations were higher in Meishan gilts. Concentrations of alanine, aspartic acid, glutamic acid and threonine were higher in Meishan than Large White × Landrace fetuses. Average-sized fetuses had higher concentrations of asparagine, leucine, lysine, phenylalanine, threonine, tyrosine and valine than the smallest fetus. This study revealed novel genotype and fetal size differences in porcine maternal-fetal amino acid status and fetal hormone and metabolite concentrations.

  10. Comprehensive data base of high-level nuclear waste glasses: September 1987 status report: Volume 2, Additional appendices

    SciTech Connect

    Kindle, C.H.; Kreiter, M.R.

    1987-12-01

    The Materials Characterization Center (MCC) is assembling a comprehensive data base (CDB) of experimental data collected for high-level nuclear waste package components. The status of the CDB is summarized in Volume I of this report. Volume II contains appendices that present data from the data base and an evaluation of glass durability models applied to the data base.

  11. Swelling behaviors of porous lignin based poly (acrylic acid).

    PubMed

    Ma, Yanli; Sun, Yajie; Fu, Yujie; Fang, Guizhen; Yan, Xingru; Guo, Zhanhu

    2016-11-01

    Supramolecular cross-linked porous lignin based poly (acrylic acid) [LBPAA] was lab-synthesized by copolymerizing lignin grafted N, N'-methylene-bisacrylamide (LM) and acrylic acid. LBPAA successfully acted as a water retention agent with salt resistance and biodegradation for agricultural applications. Lignin was found to improve its swelling behaviors with higher water retention, fast swelling and de-swelling rates. The salt tolerance was stronger in the case of LBPAA (60 PAA/40 LM) [60 wt% PAA/40 wt% LM], i.e., 145.79 g·g(-1) higher than PAA at 0.09 mM KCl solution. The effect of ion charges on the LBPAA swelling ratio was greater than that of ionic radius. The weight loss of LBPAA (60 PAA/40 LM) was 5.47%, 4.96%, and 4.56% in the soil of Tangshan, Harbin, and Sian, respectively. The soil moisture content and clay content were observed to decrease gradually with increasing the burial time. The biodegradation test of LBPAA (60 PAA/40 LM) composite exhibited different bacterial colony forming units (CFU), the soil of Tangshan was 2.0 × 10(3) CFU·g(-1) soil, 7.0 × 10(3) CFU·g(-1) soil for Harbin, and 6.10 × 10(4) CFU·g(-1) soil for Sian. However, the organic matter contents in the soils did not have significant changes (Tangshan 6.21 mg·g(-1), Harbin 0.61 mg·g(-1), and Sian 0.405 mg·g(-1)). PMID:27587327

  12. Electrospun poly(lactic acid) based conducting nanofibrous networks

    NASA Astrophysics Data System (ADS)

    Patra, S. N.; Bhattacharyya, D.; Ray, S.; Easteal, A. J.

    2009-08-01

    Multi-functionalised micro/nanostructures of conducting polymers in neat or blended forms have received much attention because of their unique properties and technological applications in electrical, magnetic and biomedical devices. Biopolymer-based conducting fibrous mats are of special interest for tissue engineering because they not only physically support tissue growth but also are electrically conductive, and thus are able to stimulate specific cell functions or trigger cell responses. They are effective for carrying current in biological environments and can thus be considered for delivering local electrical stimuli at the site of damaged tissue to promote wound healing. Electrospinning is an established way to process polymer solutions or melts into continuous fibres with diameter often in the nanometre range. This process primarily depends on a number of parameters, including the type of polymer, solution viscosity, polarity and surface tension of the solvent, electric field strength and the distance between the spinneret and the collector. The present research has included polyaniline (PANi) as the conducting polymer and poly(L-lactic acid) (PLLA) as the biopolymer. Dodecylbenzene sulphonic acid (DBSA) doped PANi and PLLA have been dissolved in a common solvent (mixtures of chloroform and dimethyl formamide (DMF)), and the solutions successfully electrospun. DMF enhanced the dielectric constant of the solvent, and tetra butyl ammonium bromide (TBAB) was used as an additive to increase the conductivity of the solution. DBSA-doped PANi/PLLA mat exhibits an almost bead-free network of nanofibres that have extraordinarily smooth surface and diameters in the range 75 to 100 nm.

  13. Solution influence on biomolecular equilibria - Nucleic acid base associations

    NASA Technical Reports Server (NTRS)

    Pohorille, A.; Pratt, L. R.; Burt, S. K.; Macelroy, R. D.

    1984-01-01

    Various attempts to construct an understanding of the influence of solution environment on biomolecular equilibria at the molecular level using computer simulation are discussed. First, the application of the formal statistical thermodynamic program for investigating biomolecular equilibria in solution is presented, addressing modeling and conceptual simplications such as perturbative methods, long-range interaction approximations, surface thermodynamics, and hydration shell. Then, Monte Carlo calculations on the associations of nucleic acid bases in both polar and nonpolar solvents such as water and carbon tetrachloride are carried out. The solvent contribution to the enthalpy of base association is positive (destabilizing) in both polar and nonpolar solvents while negative enthalpies for stacked complexes are obtained only when the solute-solute in vacuo energy is added to the total energy. The release upon association of solvent molecules from the first hydration layer around a solute to the bulk is accompanied by an increase in solute-solvent energy and decrease in solvent-solvent energy. The techniques presented are expectd to displace less molecular and more heuristic modeling of biomolecular equilibria in solution.

  14. Ligation with nucleic acid sequence-based amplification.

    PubMed

    Ong, Carmichael; Tai, Warren; Sarma, Aartik; Opal, Steven M; Artenstein, Andrew W; Tripathi, Anubhav

    2012-01-01

    This work presents a novel method for detecting nucleic acid targets using a ligation step along with an isothermal, exponential amplification step. We use an engineered ssDNA with two variable regions on the ends, allowing us to design the probe for optimal reaction kinetics and primer binding. This two-part probe is ligated by T4 DNA Ligase only when both parts bind adjacently to the target. The assay demonstrates that the expected 72-nt RNA product appears only when the synthetic target, T4 ligase, and both probe fragments are present during the ligation step. An extraneous 38-nt RNA product also appears due to linear amplification of unligated probe (P3), but its presence does not cause a false-positive result. In addition, 40 mmol/L KCl in the final amplification mix was found to be optimal. It was also found that increasing P5 in excess of P3 helped with ligation and reduced the extraneous 38-nt RNA product. The assay was also tested with a single nucleotide polymorphism target, changing one base at the ligation site. The assay was able to yield a negative signal despite only a single-base change. Finally, using P3 and P5 with longer binding sites results in increased overall sensitivity of the reaction, showing that increasing ligation efficiency can improve the assay overall. We believe that this method can be used effectively for a number of diagnostic assays. PMID:22449695

  15. Infodemiology of status epilepticus: A systematic validation of the Google Trends-based search queries.

    PubMed

    Bragazzi, Nicola Luigi; Bacigaluppi, Susanna; Robba, Chiara; Nardone, Raffaele; Trinka, Eugen; Brigo, Francesco

    2016-02-01

    People increasingly use Google looking for health-related information. We previously demonstrated that in English-speaking countries most people use this search engine to obtain information on status epilepticus (SE) definition, types/subtypes, and treatment. Now, we aimed at providing a quantitative analysis of SE-related web queries. This analysis represents an advancement, with respect to what was already previously discussed, in that the Google Trends (GT) algorithm has been further refined and correlational analyses have been carried out to validate the GT-based query volumes. Google Trends-based SE-related query volumes were well correlated with information concerning causes and pharmacological and nonpharmacological treatments. Google Trends can provide both researchers and clinicians with data on realities and contexts that are generally overlooked and underexplored by classic epidemiology. In this way, GT can foster new epidemiological studies in the field and can complement traditional epidemiological tools.

  16. Infodemiology of status epilepticus: A systematic validation of the Google Trends-based search queries.

    PubMed

    Bragazzi, Nicola Luigi; Bacigaluppi, Susanna; Robba, Chiara; Nardone, Raffaele; Trinka, Eugen; Brigo, Francesco

    2016-02-01

    People increasingly use Google looking for health-related information. We previously demonstrated that in English-speaking countries most people use this search engine to obtain information on status epilepticus (SE) definition, types/subtypes, and treatment. Now, we aimed at providing a quantitative analysis of SE-related web queries. This analysis represents an advancement, with respect to what was already previously discussed, in that the Google Trends (GT) algorithm has been further refined and correlational analyses have been carried out to validate the GT-based query volumes. Google Trends-based SE-related query volumes were well correlated with information concerning causes and pharmacological and nonpharmacological treatments. Google Trends can provide both researchers and clinicians with data on realities and contexts that are generally overlooked and underexplored by classic epidemiology. In this way, GT can foster new epidemiological studies in the field and can complement traditional epidemiological tools. PMID:26773681

  17. [Current status and further prospects of dental resin-based materials with antibacterial properties].

    PubMed

    Shi, X; Lu, H B; Mao, J; Gong, S Q

    2016-09-01

    The mode of dental antibacterial resin-based materials can be divided into two types, namely, single and combined antibacterial mode. With regard to single antibacterial mode, only one kind of antibacterial agent is added into the resin, which can be released or act as contacting antibacterial agent. The single mode resin has limitation in sterilization methods and effect. As for combined antibacterial mode, it is a combination of different types of biocides and thus maximizes the sterilizing effect, including the releasing antibacterial agent incorporated with the contacting antibacterial agent or antibacterial agents combined with calcium compound possessing biological mineralization function. In this paper, current status and further prospects of dental resin-based materials with antibacterial properties are reviewed from the perspectives of single and combined antibacterial modes to provide guidance for dental antibacterial resin material research. PMID:27596349

  18. [Current status and further prospects of dental resin-based materials with antibacterial properties].

    PubMed

    Shi, X; Lu, H B; Mao, J; Gong, S Q

    2016-09-01

    The mode of dental antibacterial resin-based materials can be divided into two types, namely, single and combined antibacterial mode. With regard to single antibacterial mode, only one kind of antibacterial agent is added into the resin, which can be released or act as contacting antibacterial agent. The single mode resin has limitation in sterilization methods and effect. As for combined antibacterial mode, it is a combination of different types of biocides and thus maximizes the sterilizing effect, including the releasing antibacterial agent incorporated with the contacting antibacterial agent or antibacterial agents combined with calcium compound possessing biological mineralization function. In this paper, current status and further prospects of dental resin-based materials with antibacterial properties are reviewed from the perspectives of single and combined antibacterial modes to provide guidance for dental antibacterial resin material research.

  19. Numeric score-based conditional and overall change-in-status indices for ordered categorical data.

    PubMed

    Lyles, Robert H; Kupper, Lawrence L; Barnhart, Huiman X; Martin, Sandra L

    2015-11-30

    Planned interventions and/or natural conditions often effect change on an ordinal categorical outcome (e.g., symptom severity). In such scenarios, it is sometimes desirable to assign a priori scores to observed changes in status, typically giving higher weight to changes of greater magnitude. We define change indices for such data based upon a multinomial model for each row of a c × c table, where the rows represent the baseline status categories. We distinguish an index designed to assess conditional changes within each baseline category from two others designed to capture overall change. One of these overall indices measures expected change across a target population. The other is scaled to capture the proportion of total possible change in the direction indicated by the data, so that it ranges from -1 (when all subjects finish in the least favorable category) to +1 (when all finish in the most favorable category). The conditional assessment of change can be informative regardless of how subjects are sampled into the baseline categories. In contrast, the overall indices become relevant when subjects are randomly sampled at baseline from the target population of interest, or when the investigator is able to make certain assumptions about the baseline status distribution in that population. We use a Dirichlet-multinomial model to obtain Bayesian credible intervals for the conditional change index that exhibit favorable small-sample frequentist properties. Simulation studies illustrate the methods, and we apply them to examples involving changes in ordinal responses for studies of sleep deprivation and activities of daily living. PMID:26137898

  20. Effects of temperature on acid-base balance and ventilation in desert iguanas.

    PubMed

    Bickler, P E

    1981-08-01

    The effects of constant and changing temperatures on blood acid-base status and pulmonary ventilation were studied in the eurythermal lizard Dipsosaurus dorsalis. Constant temperatures between 18 and 42 degrees C maintained for 24 h or more produced arterial pH changes of -0.0145 U X degrees C-1. Arterial CO2 tension (PCO2) increased from 9.9 to 32 Torr plasma [HCO-3] and total CO2 contents remained constant at near 19 and 22 mM, respectively. Under constant temperature conditions, ventilation-gas exchange ratios (VE/MCO2 and VE/MO2) were inversely related to temperature and can adequately explain the changes in arterial PCO2 and pH. During warming and cooling between 25 and 42 degrees C arterial pH, PCO2 [HCO-3], and respiratory exchange ratios (MCO2/MO2) were similar to steady-state values. Warming and cooling each took about 2 h. During the temperature changes, rapid changes in lung ventilation following steady-state patterns were seen. Blood relative alkalinity changed slightly with steady-state or changing body temperatures, whereas calculated charge on protein histidine imidazole was closely conserved. Cooling to 17-18 degrees C resulted in a transient respiratory acidosis correlated with a decline in the ratio VE/MCO2. After 12-24 h at 17-18 degrees C, pH, PCO2, and VE returned to steady-state values. The importance of thermal history of patterns of acid-base regulation in reptiles is discussed.

  1. Hemolymph acid-base balance of the crayfish Astacus leptodactylus as a function of the oxygenation and the acid-base balance of the ambient water.

    PubMed

    Dejours, P; Armand, J

    1980-07-01

    The acid-base balance of the prebranchial hemolymph of the crayfish Astacus leptodactylus was studied at various acid-base balances and levels of oxygenation of the ambient water at 13 degrees C. The water acid-base balance was controlled automatically by a pH-CO2-stat. Into water of constant titration alkalinity, TA, this device intermittenly injects carbon dioxide to maintain the pH at a preset value. Water pH was reduced to the same value either by hypercapnia (at constant TA) or by adding HCl or H2SO4 to decrease the TA (at constant CO2 tension). Decrease of hemolymph pH and increase of hemolymph PCO2 were similar for the three acidic waters. Water oxygenation changes strongly affected hemolymph ABB. In crayfish living in hyperoxic water (PO2 congruent to 600 Torr) compared to those in hypoxic water (PO2 congruent to 40 Torr), hemolymph pH was 0.3 to 0.4 unit lower and hemolymph PCO2 several times higher, the exact values of pH and PCO2 depending on the controlled ambient acid-base balance. In any study of the hemolymph acid-base balance of the crayfish, it is an important to control ambient water's acid-base balance and oxygenation as it is to control its temperature, a conclusion which probably holds true for studies on all water breathers.

  2. Meat quality, fatty acid composition of tissue and gastrointestinal content, and antioxidant status of lamb fed seed of a halophyte (Suaeda glauca).

    PubMed

    Sun, H X; Zhong, R Z; Liu, H W; Wang, M L; Sun, J Y; Zhou, D W

    2015-02-01

    Twenty-four Merino lambs were randomly assigned to four treatments: control diet (CT) consisting of 300g concentrates with ad libitum Leymus chinensis hay; C with 150g (T150), 300g (T300) and 450g (T450) Suaeda glauca seed, respectively. Meat quality, fatty acid composition of meat and lipid tissue and antioxidant status of lamb were evaluated. Inclusion of S. glauca seeds significantly increased selenium (Se) concentrations of muscle. The proportions of C18:1 trans-11 in muscle, C18:2 n-6, PUFA, n-6 series fatty acids, and the ratios of P:S in rumen contents, as well as the ratios of n-6:n-3 in adipose tissue, rumen and duodenum content have been significantly (P<0.05) improved with supplementation of S. glauca seeds to lamb diets. No significant effect was found on antioxidant status. The results suggest that S. glauca seed supplementation in lamb diets may change fatty acid composition in tissues and content of digestive tract.

  3. Ultrastructural observation of the acid-base resistant zone of all-in-one adhesives using three different acid-base challenges.

    PubMed

    Tsujimoto, Miho; Nikaido, Toru; Inoue, Go; Sadr, Alireza; Tagami, Junji

    2010-11-01

    The aim of this study was to analyze the ultrastructure of the dentin-adhesive interface using two all-in-one adhesive systems (Clearfil Tri-S Bond, TB; Tokuyama Bond Force, BF) after different acid-base challenges. Three solutions were used as acidic solutions for the acid-base challenges: a demineralizing solution (DS), a phosphoric acid solution (PA), and a hydrochloric acid solution (HCl). After the acid-base challenges, the bonded interfaces were examined by scanning electron microscopy. Thickness of the acid-base resistant zone (ABRZ) created in PA and HCl was thinner than in DS for both adhesive systems. For BF adhesive, an eroded area was observed beneath the ABRZ after immersion in PA and HCl, but not in DS. Conversely for TB adhesive, the eroded area was observed only after immersion in PA. In conclusion, although the ABRZ was observed for both all-in-one adhesive systems, its morphological features were influenced by the ingredients of both the adhesive material and acidic solution.

  4. An elementary derivation of the hard/soft-acid/base principle.

    PubMed

    Ayers, Paul W

    2005-04-01

    The hard/soft-acid/base (HSAB) principle indicates that hard acids prefer binding to hard bases (often forming bonds with substantial ionic character) while soft acids prefer binding to soft bases (often forming bonds with substantial covalent character). Though the HSAB principle is a foundational concept of the modern theory of acids and bases, the theoretical underpinnings of the HSAB principle remain murky. This paper examines the exchange reaction, wherein two molecules, one the product of reacting a hard acid and a soft base and the other the product of reacting a soft acid with a hard base, exchange substituents to form the preferred hard-hard and soft-soft product. A simple derivation shows that this reaction is exothermic, proving the validity of the HSAB principle. The analysis leads to the simple and conceptually appealing conclusion that the HSAB principle is a driven by simple electron transfer effects.

  5. ACID-BASE ACCOUNT EFFECTIVENESS FOR DETERMINATION OF MINE WASTE POTENTIAL ACIDITY. (R825549C048)

    EPA Science Inventory

    The oxidation of sulfide minerals in mine waste is a widespread source of resource degradation, often resulting in the generation of acidic water and mobilization of heavy metals. The quantity of acid forming minerals present in mine waste, dominantly as pyrite (FeS2

  6. Design and Characterization of Auxotrophy-Based Amino Acid Biosensors

    PubMed Central

    Bertels, Felix; Merker, Holger; Kost, Christian

    2012-01-01

    Efficient and inexpensive methods are required for the high-throughput quantification of amino acids in physiological fluids or microbial cell cultures. Here we develop an array of Escherichia coli biosensors to sensitively quantify eleven different amino acids. By using online databases, genes involved in amino acid biosynthesis were identified that – upon deletion – should render the corresponding mutant auxotrophic for one particular amino acid. This rational design strategy suggested genes involved in the biosynthesis of arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, tryptophan, and tyrosine as potential genetic targets. A detailed phenotypic characterization of the corresponding single-gene deletion mutants indeed confirmed that these strains could neither grow on a minimal medium lacking amino acids nor transform any other proteinogenic amino acid into the focal one. Site-specific integration of the egfp gene into the chromosome of each biosensor decreased the detection limit of the GFP-labeled cells by 30% relative to turbidometric measurements. Finally, using the biosensors to determine the amino acid concentration in the supernatants of two amino acid overproducing E. coli strains (i.e. ΔhisL and ΔtdcC) both turbidometrically and via GFP fluorescence emission and comparing the results to conventional HPLC measurements confirmed the utility of the developed biosensor system. Taken together, our study provides not only a genotypically and phenotypically well-characterized set of publicly available amino acid biosensors, but also demonstrates the feasibility of the rational design strategy used. PMID:22829942

  7. Using problem based learning and guided inquiry in a high school acid-base chemistry unit

    NASA Astrophysics Data System (ADS)

    McKinley, Katie

    The purpose of this investigation was to determine if incorporating problem based learning and guided inquiry would improve student achievement in an acid base unit for high school chemistry. The activities and labs in the unit were modified to be centered around the problem of a fish kill that students investigated. Students also participated in guided inquiry labs to increase the amount of critical thinking and problem solving being done in the classroom. The hypothesis was that the implementation of problem based learning and guided inquiry would foster student learning. Students took a pre-test and post-test on questions covering the objectives of the acid base unit. These assessments were compared to determine the effectiveness of the unit. The results indicate that the unit was effective in increasing student performance on the unit test. This study also analyzed the process of problem based learning. Problem based learning can be an effective method of engaging students in inquiry. However, designing an effective problem based learning unit requires careful design of the problem and enough structure to assure students learn the intended content.

  8. Dietary zinc deficiency affects blood linoleic acid: dihomo-gamma-linolenic acid (LA:DGLA) ratio; a reactive physiological marker of zinc status in vivo (Gallus gallus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary Zinc (Zn) deficiency affects approximately 30% of the world’s population. Zinc is a vital micronutrient and is important for the body’s ability to function. To date, accurate biological markers of the Zn subject’s status are still needed. The aim of this study was to evaluate the chicken mod...

  9. Electroreduction and acid-base properties of dipyrrolylquinoxalines.

    PubMed

    Fu, Zhen; Zhang, Min; Zhu, Weihua; Karnas, Elizabeth; Mase, Kentaro; Ohkubo, Kei; Sessler, Jonathan L; Fukuzumi, Shunichi; Kadish, Karl M

    2012-10-18

    The electroreduction and acid-base properties of dipyrrolylquinoxalines of the form H(2)DPQ, H(2)DPQ(NO(2)), and H(2)DPQ(NO(2))(2) were investigated in benzonitrile (PhCN) containing 0.1 M tetra-n-butylammonium perchlorate (TBAP). This study focuses on elucidating the complete electrochemistry, spectroelectrochemistry, and acid-base properties of H(2)DPQ(NO(2))(n) (n = 0, 1, or 2) in PhCN before and after the addition of trifluoroacetic acid (TFA), tetra-n-butylammonium hydroxide (TBAOH), tetra-n-butylammonium fluoride (TBAF), or tetra-n-butylammonium acetate (TBAOAc) to solution. Electrochemical and spectroelectrochemical data provide support for the formation of a monodeprotonated anion after disproportionation of a dipyrrolylquinoxaline radical anion produced initially. The generated monoanion is then further reduced in two reversible one-electron-transfer steps at more negative potentials in the case of H(2)DPQ(NO(2)) and H(2)DPQ(NO(2))(2). Electrochemically monitored titrations of H(2)DPQ(NO(2))(n) with OH(-), F(-), or OAc(-) (in the form of TBA(+)X(-) salts) give rise to the same monodeprotonated H(2)DPQ(NO(2))(n) produced during electroreduction in PhCN. This latter anion can then be reduced in two additional one-electron-transfer steps in the case of H(2)DPQ(NO(2)) and H(2)DPQ(NO(2))(2). Spectroscopically monitored titrations of H(2)DPQ(NO(2))(n) with X(-) show a 1:2 stoichiometry and provide evidence for the production of both [H(2)DPQ(NO(2))(n)](-) and XHX(-). The spectroscopically measured equilibrium constants range from log β(2) = 5.3 for the reaction of H(2)DPQ with TBAOAc to log β(2) = 8.8 for the reaction of H(2)DPQ(NO(2))(2) with TBAOH. These results are consistent with a combined deprotonation and anion binding process. Equilibrium constants for the addition of one H(+) to each quinoxaline nitrogen of H(2)DPQ, H(2)DPQ(NO(2)), and H(2)DPQ(NO(2))(2) in PhCN containing 0.1 M TBAP were also determined via electrochemical and spectroscopic means

  10. Dose and duration effect of alpha-tocopheryl acetate supplementation on chicken meat fatty acid composition, tocopherol content, and oxidative status.

    PubMed

    Bou, Ricard; Grimpa, Stella; Baucells, Maria D; Codony, Rafael; Guardiola, Francesc

    2006-07-12

    The effects of dietary alpha-tocopheryl acetate (alpha-TA) doses (75, 150, and 225 mg/kg) and the duration of this supplementation (0, 10, 21, 32, and 43 days prior to slaughter) on fatty acid composition, alpha-tocopherol content, and oxidative status were studied either in raw or in cooked dark chicken meat with its skin. With regard to fatty acid composition, raw meat was affected by both dietary factors. Various polyunsaturated fatty acids decreased as a result of higher alpha-TA doses, whereas these fatty acids increased with longer supplementation periods. Cooked meat showed similar trends for the duration of alpha-TA supplementation. On the other hand, alpha-tocopherol content in raw and cooked meat increased as a result of the dose and duration of alpha-TA supplementation. Formation of lipid hydroperoxides and thiobarbituric acid values of these meats were also influenced by these two dietary factors, and the dietary combination of 150 mg/kg of alpha-TA during the last 32 days was optimal in terms of supplementation costs and meat oxidative stability.

  11. Social factors ameliorate psychiatric disorders in community-based asylum seekers independent of visa status.

    PubMed

    Hocking, Debbie C; Kennedy, Gerard A; Sundram, Suresh

    2015-12-15

    The impact of industrialised host nations' deterrent immigration policies on the mental health of forced migrants has not been well characterised. The present study investigated the impact of Australia's refugee determination process (RDP) on psychiatric morbidity in community-based asylum-seekers (AS) and refugees. Psychiatric morbidity was predicted to be greater in AS than refugees, and to persist or increase as a function of time in the RDP. The effect on mental health of demographic and socio-political factors such as health cover and work rights were also investigated. Psychiatric morbidity was measured prospectively on five mental health indices at baseline (T1, n=131) and an average of 15.7 months later (T2, n=56). Psychiatric morbidity in AS significantly decreased between time points such that it was no longer greater than that of refugees at T2. Caseness of PTSD and demoralisation reduced in AS who gained protection; however, those who maintained asylum-seeker status at T2 also had a significant reduction in PTS and depression symptom severity. Reduced PTS and demoralisation symptoms were associated with securing work rights and health cover. Living in the community with work rights and access to health cover significantly improves psychiatric symptoms in forced migrants irrespective of their protection status.

  12. Social factors ameliorate psychiatric disorders in community-based asylum seekers independent of visa status.

    PubMed

    Hocking, Debbie C; Kennedy, Gerard A; Sundram, Suresh

    2015-12-15

    The impact of industrialised host nations' deterrent immigration policies on the mental health of forced migrants has not been well characterised. The present study investigated the impact of Australia's refugee determination process (RDP) on psychiatric morbidity in community-based asylum-seekers (AS) and refugees. Psychiatric morbidity was predicted to be greater in AS than refugees, and to persist or increase as a function of time in the RDP. The effect on mental health of demographic and socio-political factors such as health cover and work rights were also investigated. Psychiatric morbidity was measured prospectively on five mental health indices at baseline (T1, n=131) and an average of 15.7 months later (T2, n=56). Psychiatric morbidity in AS significantly decreased between time points such that it was no longer greater than that of refugees at T2. Caseness of PTSD and demoralisation reduced in AS who gained protection; however, those who maintained asylum-seeker status at T2 also had a significant reduction in PTS and depression symptom severity. Reduced PTS and demoralisation symptoms were associated with securing work rights and health cover. Living in the community with work rights and access to health cover significantly improves psychiatric symptoms in forced migrants irrespective of their protection status. PMID:26518226

  13. Non-invasive health status detection system using Gabor filters based on facial block texture features.

    PubMed

    Shu, Ting; Zhang, Bob

    2015-04-01

    Blood tests allow doctors to check for certain diseases and conditions. However, using a syringe to extract the blood can be deemed invasive, slightly painful, and its analysis time consuming. In this paper, we propose a new non-invasive system to detect the health status (Healthy or Diseased) of an individual based on facial block texture features extracted using the Gabor filter. Our system first uses a non-invasive capture device to collect facial images. Next, four facial blocks are located on these images to represent them. Afterwards, each facial block is convolved with a Gabor filter bank to calculate its texture value. Classification is finally performed using K-Nearest Neighbor and Support Vector Machines via a Library for Support Vector Machines (with four kernel functions). The system was tested on a dataset consisting of 100 Healthy and 100 Diseased (with 13 forms of illnesses) samples. Experimental results show that the proposed system can detect the health status with an accuracy of 93 %, a sensitivity of 94 %, a specificity of 92 %, using a combination of the Gabor filters and facial blocks. PMID:25722202

  14. A Comparison of Different Teaching Designs of "Acids and Bases" Subject

    ERIC Educational Resources Information Center

    Ültay, Neslihan; Çalik, Muammer

    2016-01-01

    Inability to link the acid-base concepts with daily life phenomena (as contexts) highlights the need for further research on the context-based acid-base chemistry. In this vein, the aim of this study is to investigate the effects of different teaching designs (REACT strategy, 5Es learning model and traditional (existing) instruction) relevant with…

  15. Hands-On Science: Is It an Acid or a Base? These Colorful Tests Tell All!

    ERIC Educational Resources Information Center

    VanCleave, Janice

    1998-01-01

    Two hands-on science activities for K-6 students teach them how to determine if something is an acid or a base. The activities require acid/base indicator juice, testing strips, and a base solution. A recipe for making them in the classroom using red cabbage and baking soda is provided. (SM)

  16. Aristolochic Acids

    MedlinePlus

    ... Sciences NIH-HHS www.niehs.nih.gov Aristolochic Acids Key Points Report on Carcinogens Status Known to be human carcinogens Aristolochia Clematitis Aristolochic Acids n Known human carcinogens n Found in certain ...

  17. 77 FR 16126 - Microbiology Devices; Reclassification of Nucleic Acid-Based Systems for Mycobacterium tuberculosis

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-19

    ... Food and Drug Administration 21 CFR Part 866 Microbiology Devices; Reclassification of Nucleic Acid...: Proposed rule. SUMMARY: The Food and Drug Administration (FDA) is proposing to reclassify nucleic acid... effectiveness of the device for its intended use. II. Regulatory Background of the Device Nucleic acid-based...

  18. Evaluation of the number of ionogenic groups of inulinase by acid-base titration.

    PubMed

    Kovaleva, T A; Holyavka, M G; Rezvan, S G; Kozhedub, S V

    2008-06-01

    Acid base titration showed that Aspergillus awamori inulinase includes 178 asparaginic and glutamic acid residues, 20 histidine, 10 serine, and 34 lysine and tyrosine residues. Denaturation temperature for this enzyme was calculated using analysis of the proportion of stabilizing and destabilizing amino acids in the molecule.

  19. Current status of environmental barrier coatings for Si-Based ceramics

    NASA Technical Reports Server (NTRS)

    Lee, K. N.

    2000-01-01

    Silicon-based ceramics are the leading candidates for high temperature structural components in next generation gas turbine engines. One key drawback of silicon-based ceramics for such an application is volatilization of the protective silica scale in water vapor and the resulting rapid ceramic recession. Therefore, the realization of Si-based ceramics components in advanced gas turbine engines depends on the development of protection schemes from water vapor attack. Currently, plasma-sprayed external environmental barrier coatings (EBCs) arc the most promising approach. In the late 1980s and early 1990s a wide range of refractory oxide materials were tested as coatings on Si-based ceramics to provide protection from hot corrosion. After the discovery of silica volatilization in water vapor in the early 1990s, the focus of EBC development research has been shifted towards the protection from water vapor attack. Experience learned form the earlier coating developmental effort provided the foundation upon which more complex and advanced EBC coatings have been developed. This paper will discuss the brief history and the current status of EBC development for Si-based ceramics with the main focus on water vapor protection.

  20. The influence of a vegetarian diet on the fatty acid composition of human milk and the essential fatty acid status of the infant.

    PubMed

    Sanders, T A; Reddy, S

    1992-04-01

    Vegan and vegetarian diets supply higher amounts of linoleic acid than those of omnivores. Intakes of alpha-linolenic acid (18:3n-3) are variable, depending on the oils used, but are generally high in vegans. Docosahexaenoic acid (22:6n-3) (DHA) is absent from vegan and many vegetarian diets. Cord plasma and cord artery phospholipid levels of Hindu vegetarians contained less DHA and more docosapentaenoic acid (22:5n-6) compared with those of omnivore control subjects. These differences in fatty acid composition were not statistically related to differences in birth weight, head circumference, or length. In human milk from vegans, vegetarians, and omnivores, the mean percentage in total fatty acids of 18:2n-6 was 23.8%, 19.7%, and 10.9%, respectively; that of 18:3n-3 was 1.36%, 1.25%, and 0.49%, respectively; and that of 22:6n-3 was 0.14%, 0.30%, and 0.37%, respectively. The proportion of DHA in erythrocyte total lipids of infants breast-fed by vegans was 1.9% compared with 3.7% in infants fed a milk formula containing butterfat as the sole source of fat and 6.2% in infants breast-fed by omnivores at 14 weeks postpartum. The ratio of linoleic/alpha-linolenic acid in the diet was predictive of the proportion of eicosapentaenoic acid but not that of DHA in infant red blood cell lipids. It is concluded that the intakes of linoleic acid and DHA are the major determinants of the proportion of DHA in plasma and red blood cell lipids.

  1. The influence of a vegetarian diet on the fatty acid composition of human milk and the essential fatty acid status of the infant.

    PubMed

    Sanders, T A; Reddy, S

    1992-04-01

    Vegan and vegetarian diets supply higher amounts of linoleic acid than those of omnivores. Intakes of alpha-linolenic acid (18:3n-3) are variable, depending on the oils used, but are generally high in vegans. Docosahexaenoic acid (22:6n-3) (DHA) is absent from vegan and many vegetarian diets. Cord plasma and cord artery phospholipid levels of Hindu vegetarians contained less DHA and more docosapentaenoic acid (22:5n-6) compared with those of omnivore control subjects. These differences in fatty acid composition were not statistically related to differences in birth weight, head circumference, or length. In human milk from vegans, vegetarians, and omnivores, the mean percentage in total fatty acids of 18:2n-6 was 23.8%, 19.7%, and 10.9%, respectively; that of 18:3n-3 was 1.36%, 1.25%, and 0.49%, respectively; and that of 22:6n-3 was 0.14%, 0.30%, and 0.37%, respectively. The proportion of DHA in erythrocyte total lipids of infants breast-fed by vegans was 1.9% compared with 3.7% in infants fed a milk formula containing butterfat as the sole source of fat and 6.2% in infants breast-fed by omnivores at 14 weeks postpartum. The ratio of linoleic/alpha-linolenic acid in the diet was predictive of the proportion of eicosapentaenoic acid but not that of DHA in infant red blood cell lipids. It is concluded that the intakes of linoleic acid and DHA are the major determinants of the proportion of DHA in plasma and red blood cell lipids. PMID:1560329

  2. [Development of Nucleic Acid-Based Adjuvant for Cancer Immunotherapy].

    PubMed

    Kobiyama, Kouji; Ishii, Ken J

    2015-09-01

    Since the discovery of the human T cell-defined tumor antigen, the cancer immunotherapy field has rapidly progressed, with the research and development of cancer immunotherapy, including cancer vaccines, being conducted actively. However, the disadvantages of most cancer vaccines include relatively weak immunogenicity and immune escape or exhaustion. Adjuvants with innate immunostimulatory activities have been used to overcome these issues, and these agents have been shown to enhance the immunogenicity of cancer vaccines and to act as mono-therapeutic anti-tumor agents. CpG ODN, an agonist for TLR9, is one of the promising nucleic acid-based adjuvants, and it is a potent inducer of innate immune effector functions. CpG ODN suppresses tumor growth in the absence of tumor antigens and peptide administration. Therefore, CpG ODN is expected to be useful as a cancer vaccine adjuvant as well as a cancer immunotherapy agent. In this review, we discuss the potential therapeutic applications and mechanisms of CpG ODN for cancer immunotherapy.

  3. Environmental applications of poly(amic acid)-based nanomaterials.

    PubMed

    Okello, Veronica A; Du, Nian; Deng, Boling; Sadik, Omowunmi A

    2011-05-01

    Nanoscale materials offer new possibilities for the development of novel remediation and environmental monitoring technologies. Different nanoscale materials have been exploited for preventing environmental degradation and pollutant transformation. However, the rapid self-aggregation of nanoparticles or their association with suspended solids or sediments where they could bioaccumulate supports the need for polymeric coatings to improve mobility, allows faster site cleanups and reduces remediation cost. The ideal material must be able to coordinate different nanomaterials functionalities and exhibit the potential for reusability. We hereby describe two novel environmental applications of nanostructured poly (amic acid)-based (nPAA) materials. In the first application, nPAA was used as both reductant and stabilizer during the in situ chemical reduction of chromium(vi) to chromium(iii). Results showed that Cr(vi) species were rapidly reduced within the concentration range of 10(-1) to 10(2) mM with efficiency of 99.9% at 40 °C in water samples and 90% at 40 °C in soil samples respectively. Furthermore, the presence of PdNPs on the PAA-Au electrode was found to significantly enhance the rate of reduction. In the second application, nPAA membranes were tested as filters to capture, isolate and detect nanosilver. Preliminary results demonstrate the capability of the nPAA membranes to quantitatively capture nanoparticles from suspension and quantify their abundance on the membranes. Silver nanoparticles detection at concentrations near the toxic threshold of silver was also demonstrated.

  4. Hyaluronic Acid Based Hydrogels for Regenerative Medicine Applications.

    PubMed

    Borzacchiello, Assunta; Russo, Luisa; Malle, Birgitte M; Schwach-Abdellaoui, Khadija; Ambrosio, Luigi

    2015-01-01

    Hyaluronic acid (HA) hydrogels, obtained by cross-linking HA molecules with divinyl sulfone (DVS) based on a simple, reproducible, and safe process that does not employ any organic solvents, were developed. Owing to an innovative preparation method the resulting homogeneous hydrogels do not contain any detectable residual cross-linking agent and are easier to inject through a fine needle. HA hydrogels were characterized in terms of degradation and biological properties, viscoelasticity, injectability, and network structural parameters. They exhibit a rheological behaviour typical of strong gels and show improved viscoelastic properties by increasing HA concentration and decreasing HA/DVS weight ratio. Furthermore, it was demonstrated that processes such as sterilization and extrusion through clinical needles do not imply significant alteration of viscoelastic properties. Both SANS and rheological tests indicated that the cross-links appear to compact the network, resulting in a reduction of the mesh size by increasing the cross-linker amount. In vitro degradation tests of the HA hydrogels demonstrated that these new hydrogels show a good stability against enzymatic degradation, which increases by increasing HA concentration and decreasing HA/DVS weight ratio. Finally, the hydrogels show a good biocompatibility confirmed by in vitro tests. PMID:26090451

  5. [Development of Nucleic Acid-Based Adjuvant for Cancer Immunotherapy].

    PubMed

    Kobiyama, Kouji; Ishii, Ken J

    2015-09-01

    Since the discovery of the human T cell-defined tumor antigen, the cancer immunotherapy field has rapidly progressed, with the research and development of cancer immunotherapy, including cancer vaccines, being conducted actively. However, the disadvantages of most cancer vaccines include relatively weak immunogenicity and immune escape or exhaustion. Adjuvants with innate immunostimulatory activities have been used to overcome these issues, and these agents have been shown to enhance the immunogenicity of cancer vaccines and to act as mono-therapeutic anti-tumor agents. CpG ODN, an agonist for TLR9, is one of the promising nucleic acid-based adjuvants, and it is a potent inducer of innate immune effector functions. CpG ODN suppresses tumor growth in the absence of tumor antigens and peptide administration. Therefore, CpG ODN is expected to be useful as a cancer vaccine adjuvant as well as a cancer immunotherapy agent. In this review, we discuss the potential therapeutic applications and mechanisms of CpG ODN for cancer immunotherapy. PMID:26469159

  6. Hyaluronic Acid Based Hydrogels for Regenerative Medicine Applications

    PubMed Central

    Borzacchiello, Assunta; Russo, Luisa; Malle, Birgitte M.; Schwach-Abdellaoui, Khadija; Ambrosio, Luigi

    2015-01-01

    Hyaluronic acid (HA) hydrogels, obtained by cross-linking HA molecules with divinyl sulfone (DVS) based on a simple, reproducible, and safe process that does not employ any organic solvents, were developed. Owing to an innovative preparation method the resulting homogeneous hydrogels do not contain any detectable residual cross-linking agent and are easier to inject through a fine needle. HA hydrogels were characterized in terms of degradation and biological properties, viscoelasticity, injectability, and network structural parameters. They exhibit a rheological behaviour typical of strong gels and show improved viscoelastic properties by increasing HA concentration and decreasing HA/DVS weight ratio. Furthermore, it was demonstrated that processes such as sterilization and extrusion through clinical needles do not imply significant alteration of viscoelastic properties. Both SANS and rheological tests indicated that the cross-links appear to compact the network, resulting in a reduction of the mesh size by increasing the cross-linker amount. In vitro degradation tests of the HA hydrogels demonstrated that these new hydrogels show a good stability against enzymatic degradation, which increases by increasing HA concentration and decreasing HA/DVS weight ratio. Finally, the hydrogels show a good biocompatibility confirmed by in vitro tests. PMID:26090451

  7. Improving pharmacy students' understanding and long-term retention of acid-base chemistry.

    PubMed

    Roche, Victoria F

    2007-12-15

    Despite repeated exposure to the principles underlying the behavior of organic acids and bases in aqueous solution, some pharmacy students remain confused about the topic of acid-base chemistry. Since a majority of organic drug molecules have acid-base character, the ability to predict their reactivity and the extent to which they will ionize in a given medium is paramount to students' understanding of essentially all aspects of drug action in vivo and in vitro. This manuscript presents a medicinal chemistry lesson in the fundamentals of acid-base chemistry that many pharmacy students have found enlightening and clarifying.

  8. Acid-base properties of sorbents based on modified zirconium(IV) phosphates

    SciTech Connect

    Bekrenev, A.V.; Pyartman, A.K.

    1995-11-01

    Modifying and doping syntheses are widely used to improve the reproducibility of ion-exchange properties and to increase the capacity of inorganic ion exchangers. Numerous examples of doping zirconium phosphate ion exchangers with cationic or anionic additives are known. The aim of this work was to investigate the acid-base properties of zirconium phosphates modified with anionic additives (phthalate and sulfosalicylate ions) in comparison with unmodified samples.

  9. Acid-Base and Plasma Biochemical Changes Using Crystalloid Fluids in Stranded Juvenile Loggerhead Sea Turtles (Caretta caretta)

    PubMed Central

    Camacho, María; Quintana, María del Pino; Calabuig, Pascual; Luzardo, Octavio P.; Boada, Luis D.; Zumbado, Manuel; Orós, Jorge

    2015-01-01

    Aim The aim of this study was to compare the efficacy and effects on acid-base and electrolyte status of several crystalloid fluids in 57 stranded juvenile loggerhead turtles. Methods Within a rehabilitation program four different crystalloid fluids were administered (0.9% Na Cl solution; 5% dextrose + 0.9% Na Cl solutions 1:1; 0.9% Na Cl + lactated Ringer's solutions 1:1; lactated Ringer's solution). Crystalloid fluids were intracoelomically administered during three days (20 ml/kg/day). Animals were sampled at three different moments: Upon admission for evaluating the type of acid-base or biochemical disorder, post-fluid therapy treatment for controlling the evolution of the disorder, and post-recovery period for obtaining the baseline values for rehabilitated loggerhead turtles. Each sample was analyzed with a portable electronic blood analyzer for pH, pO2, pCO2, lactate, sodium, potassium, chloride, glucose, and BUN concentration. Admission and post-fluid therapy treatment values were compared with those obtained for each turtle immediately before release. Results The highest percentage of acid-base recovery and electrolyte balance was observed in turtles treated with mixed saline-lactated Ringer’s solution (63.6%), followed by turtles treated with physiological saline solution (55%), lactated Ringer’s solution (33.3%), and dextrose-saline solutions (10%). Most turtles treated with lactated Ringer’s solution had lower lactate concentrations compared with their initial values; however, 66.6% of turtles treated with lactated Ringer’s solution had metabolic alkalosis after therapy. Significant higher concentrations of glucose were detected after saline-dextrose administration compared with all the remaining fluids. Conclusions This is the first study evaluating the effects of several crystalloid fluids on the acid-base status and plasma biochemical values in stranded loggerhead sea turtles. Reference convalescent venous blood gas, acid-base, and plasma

  10. Polyol and Amino Acid-Based Biosurfactants, Builders, and Hydrogels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter reviews different detergent materials which have been synthesized from natural agricultural commodities. Background information, which gives reasons why the use of biobased materials may be advantageous, is presented. Detergent builders from L-aspartic acid, citric acid and D-sorbitol...

  11. Chemical and biological status of lakes and streams in the upper midwest: assessment of acidic deposition effects

    USGS Publications Warehouse

    Wiener, J.G.; Eilers, J.M.

    1987-01-01

    Many lakes in three areas in the Upper Midwest - northeastern Minnesota, northern Wisconsin, and the Upper Peninsula of Michigan - have low acid neutralizing capacity (ANC) and may be susceptible to change by acidic deposition. Northcentral Wisconsin and the Upper Peninsula of Michigan together contain about 150-300 acidic lakes (ANC ≤ 0), whereas none have been found in Minnesota. These acidic lakes are precipitation-dominated, Clearwater seepage lakes having small surface area, shallow depth, and low concentrations of dissolved organic carbon. The spatial distribution of these acidic lakes parallels a west to east gradient of increasing sulfate and hydrogen ion deposition. Several of these acidic lakes exhibit chemical characteristics and biological changes consistent with those observed elsewhere in waters reported to be acidified by acidic deposition. However, an hypothesis of recent lake acidification is not supported by analyses of either historical chemical data or diatom remains in lake sediments, and natural sources of acidity and alternative ecological processes have not been conclusively eliminated as causative factors. Streams in this three-state region have high ANC and appear to be insensitive to acidic deposition. The species richness and composition of lacustrine fish communities in the region are partly related to pH and associated chemical factors. Sport fishes considered acid-sensitive and of primary concern with regard to acidification include walleye, smallmouth bass, and black crappie. The fishery in at least one lake, Morgan Lake in Wisconsin (pH 4.6), may have declined because of acidification. Given the general lack of quantitative fishery data for acidic Wisconsin and Michigan lakes, however, more general conclusions concerning impacts or the absence of impacts of acidification on the region's fishery resources are not possible.

  12. Effects of glucomannan-enriched, aronia juice-based supplement on cellular antioxidant enzymes and membrane lipid status in subjects with abdominal obesity.

    PubMed

    Kardum, Nevena; Petrović-Oggiano, Gordana; Takic, Marija; Glibetić, Natalija; Zec, Manja; Debeljak-Martacic, Jasmina; Konić-Ristić, Aleksandra

    2014-01-01

    The aim of this study was to analyze the effects of a 4-week-long consumption of glucomannan-enriched, aronia juice-based supplement on anthropometric parameters, membrane fatty acid profile, and status of antioxidant enzymes in erythrocytes obtained from postmenopausal women with abdominal obesity. Twenty women aged 45-65 with a mean body mass index (BMI) of 36.1 ± 4.4 kg/m(2) and waist circumference of 104.8 ± 10.1 cm were enrolled. Participants were instructed to consume 100 mL of supplement per day as part of their regular diet. A significant increase in the content of n-3 (P < 0.05) polyunsaturated fatty acids in membrane phospholipids was observed, with a marked increase in the level of docosahexaenoic fatty acid (P < 0.05). Accordingly, a decrease in the n-6 and n-3 fatty acids ratio was observed (P < 0.05). The observed effects were accompanied with an increase in glutathione peroxidase activity (P < 0.05). Values for BMI (P < 0.001), waist circumference (P < 0.001), and systolic blood pressure (P < 0.05) were significantly lower after the intervention. The obtained results indicate a positive impact of tested supplement on cellular oxidative damage, blood pressure, and anthropometric indices of obesity.

  13. Effects of Glucomannan-Enriched, Aronia Juice-Based Supplement on Cellular Antioxidant Enzymes and Membrane Lipid Status in Subjects with Abdominal Obesity

    PubMed Central

    Petrović-Oggiano, Gordana; Glibetić, Natalija; Zec, Manja; Debeljak-Martacic, Jasmina; Konić-Ristić, Aleksandra

    2014-01-01

    The aim of this study was to analyze the effects of a 4-week-long consumption of glucomannan-enriched, aronia juice-based supplement on anthropometric parameters, membrane fatty acid profile, and status of antioxidant enzymes in erythrocytes obtained from postmenopausal women with abdominal obesity. Twenty women aged 45–65 with a mean body mass index (BMI) of 36.1 ± 4.4 kg/m2 and waist circumference of 104.8 ± 10.1 cm were enrolled. Participants were instructed to consume 100 mL of supplement per day as part of their regular diet. A significant increase in the content of n-3 (P < 0.05) polyunsaturated fatty acids in membrane phospholipids was observed, with a marked increase in the level of docosahexaenoic fatty acid (P < 0.05). Accordingly, a decrease in the n-6 and n-3 fatty acids ratio was observed (P < 0.05). The observed effects were accompanied with an increase in glutathione peroxidase activity (P < 0.05). Values for BMI (P < 0.001), waist circumference (P < 0.001), and systolic blood pressure (P < 0.05) were significantly lower after the intervention. The obtained results indicate a positive impact of tested supplement on cellular oxidative damage, blood pressure, and anthropometric indices of obesity. PMID:25574495

  14. Echium oil and linseed oil as alternatives for fish oil in the maternal diet: Blood fatty acid profiles and oxidative status of sows and piglets.

    PubMed

    Tanghe, S; Millet, S; De Smet, S

    2013-07-01

    Echium oil (source of stearidonic acid) and linseed oil (source of α-linolenic acid) were evaluated as alternatives for fish oil in the diet of sows to increase the docosahexaenoic acid (DHA) status of the offspring. The hypothesis was that echium oil would be more efficient than linseed oil to increase the DHA concentration, as it bypasses the enzyme Δ6-desaturase. In addition, it was determined whether adding PUFA to the diet affected the plasma oxidative status. Sows were fed either a palm oil diet or a diet containing 1% linseed oil, echium oil, or fish oil from d 73 of gestation and during lactation (n = 16 per dietary treatment). Total oil concentrations in the diets were similar among dietary treatments. Blood samples were taken for fatty acid analysis and oxidative status of sows on d 73 and 93 of gestation and at parturition and the lightest and heaviest piglet per litter at birth and weaning. Colostrum was also sampled. No effect of diet was observed on total number of piglets born (13.7 ± 0.4), number of weaned piglets (10.8 ± 0.4), and gestation length (114.8 ± 0.2 d). Piglets from sows fed fish oil had lighter birth weights (1.41 ± 0.03 kg) than piglets from the linseed oil diet (1.54 ± 0.03 kg; P = 0.006), with no difference between the palm oil (1.45 ± 0.03 kg) and echium oil diet (1.49 ± 0.03 kg). Daily BW gain until weaning was less for piglets from sows fed the fish oil diet (214 ± 5 g) compared with piglets from sows fed the echium oil (240 ± 5 g; P < 0.001) or linseed oil diet (234 ± 5 g; P = 0.02). Compared with the palm oil diet, echium and linseed oil in the maternal diet increased the DHA concentration in the colostrum and the sow and piglet plasma to the same extent (1.1 to 1.4-fold; P < 0.001). On the fish oil diet, 20.7-fold, 10-fold, and 2.4-fold increases in DHA in colostrum, sow, and piglet plasma, respectively, were observed (P < 0.001). At 1% in the maternal diet, echium oil had, thus, no benefit over linseed oil and

  15. Plasma omega 3 polyunsaturated fatty acid status and monounsaturated fatty acids are altered by chronic social stress and predict endocrine responses to acute stress in titi monkeys

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Disturbances in fatty acid (FA) metabolism may link chronic psychological stress, endocrine responsiveness, and psychopathology. Therefore, lipid metabolome-wide responses and their relationships with endocrine (cortisol; insulin; adiponectin) responsiveness to acute stress (AS) were assessed in a ...

  16. Nitric acid: modeling osmotic coefficients and acid-base dissociation using the BIMSA theory.

    PubMed

    Ruas, Alexandre; Pochon, Patrick; Simonin, Jean-Pierre; Moisy, Philippe

    2010-11-14

    This work is aimed at a description of the thermodynamic properties of highly concentrated aqueous solutions of nitric acid salts at 25 °C within the binding mean spherical approximation (BIMSA) theory. The predictive capability of this model was examined. First, Raman spectroscopy was used to study the proportion of associated nitric acid as a function of concentration. The corresponding apparent association constant values were compared with literature values. Besides, the BIMSA model, taking into account complex formation, was used to represent literature experimental osmotic coefficient variation with concentration. This theoretical description led to an assessment of the degree of association. The so calculated amount of associated nitric acid coincides accurately with our Raman experimental results up to a high concentration of acid.

  17. Occupation, socioeconomic status, and brain tumor mortality: a death certificate-based case-control study.

    PubMed

    Demers, P A; Vaughan, T L; Schommer, R R

    1991-09-01

    The relationships between brain tumor mortality and occupation and socioeconomic status (SES) were evaluated in a death certificate-based case-control study. The cases consisted of 904 white men aged 20 years and older who died of a brain tumor in Washington state between 1969 and 1978. For each case a white male control of the same age was chosen. A consistent pattern of increasing risk with increasing SES was seen for all brain tumors as well as for gliomas and astrocytomas. After adjustment for SES, stationary engineers were found to be at excess risk across all histologies based on six cases vs no controls with lower 95% confidence intervals of 2.3 for all brain tumors, 2.8 for gliomas (based on three cases), and 2.1 for astrocytic tumors (based on two cases). Excesses of astrocytic tumors also were observed for petroleum refinery workers (OR = 8.8, CI = 2.2-35.2), forestry workers (OR = 8.5, CI = 1.1-63.4), and cleaning service workers (OR = 2.7, CI = 1.1-6.7).

  18. Populism vs. elitism: social consensus and social status as bases of attitude certainty.

    PubMed

    Prislin, Radmila; Shaffer, Emily; Crowder, Marisa

    2012-01-01

    This study examined the effects of social consensus and social status on attitude certainty that is conceptualized multi-dimensionally as perceived clarity and correctness of one's attitude. In a mock opinion exchange about a social issue, participants were either supported (high consensus) or opposed (low consensus) by most of the confederates. They were informed that their opinion (high status) or their opponents' opinion (low status) had the alleged psychological significance indicative of future success. Post-experimental attitude clarity was significantly greater when attitudinal position was associated with high rather than low status. Attitude correctness was interactively affected by social status and social consensus. Supporting the compensatory effect hypothesis, attitude correctness was comparable across the levels of social consensus as long as they were associated with high status, and across the levels of social status as long as they were associated with high social consensus. PMID:22558827

  19. Stable isotope evidence for sex- and status-based variations in diet and life history at medieval Trino Vercellese, Italy.

    PubMed

    Reitsema, Laurie J; Vercellotti, Giuseppe

    2012-08-01

    The medieval period in Europe was a time of unprecedented social complexity that affected human diet. The diets of certain subgroups-for example, children, women, and the poor-are chronically underrepresented in historical sources from the medieval period. To better understand diet and the distribution of foods during the medieval period, we investigated stable carbon and nitrogen isotope ratios of 30 individuals from Trino Vercellese, Northern Italy (8th-13th c.). Specifically, we examined diet differences between subgroups (males and females, and high- and low-status individuals), and diet change throughout the life course among these groups by comparing dentine and bone collagen. Our results show a diet based on terrestrial resources with input from C(4) plants, which could include proso and/or foxtail millet. Diets of low-status males differ from those of females (both status groups) and of high-status males. These differences develop in adulthood. Childhood diets are similar among the subgroups, but sex- and status-based differences appear in adulthood. We discuss the possibility of cultural buffering and dietary selectivity of females and high-status individuals.

  20. Construction of Multi-dimensional Arterial Health Status Map based on Molecular and Clinical Measurements, Fuzzy System and Data Cubes

    PubMed Central

    Chan, Lawrence W.C.; Benzie, Iris F.F.; Lau, Thomas Y.H.; Zheng, Yongping; Wong, Alex K.S.; Liu, Y.; Chan, Phoebe S.T.

    2008-01-01

    Atherosclerosis results from inflammatory processes involving biomarkers, such as lipid profile, haemoglobin A1C, oxidative stress, coronary artery calcium score and flow-mediated endothelial response through nitric oxide. This paper proposes a health status coefficient, which comprehends molecular and clinical measurements concerning atherosclerosis to provide a measure of arterial health. An arterial health status map is produced to map the multi-dimensional measurements to the health status coefficient. The mapping is modeled by a fuzzy system embedded with the health domain expert knowledge. The measurements obtained from the pilot study are used to tune the fuzzy system. The inferred arterial health coefficients are stored into the data cubes of a multi-dimensional database. Due to this adaptability and transparency of fuzzy system, the health status map can be easily updated when the refinement of fuzzy rule base is needed or new measurements are obtained. PMID:21347120

  1. Production of Jatropha biodiesel fuel over sulfonic acid-based solid acids.

    PubMed

    Chen, Shih-Yuan; Lao-Ubol, Supranee; Mochizuki, Takehisa; Abe, Yohko; Toba, Makoto; Yoshimura, Yuji

    2014-04-01

    Sulfonic acid-functionalized platelet SBA-15 mesoporous silica with an acid capacity of 2.44mmol H(+) g-cat(-1) (shortly termed 15SA-SBA-15-p) was one-pot synthesized by co-condensation method. When applied as solid acid catalyst in synthesis of Jatropha biodiesel fuel (BDF), the 15SA-SBA-15-p catalyst showed higher activity and resistances to water and free fatty acid (FFA) than commercial sulfonic resins of Amberlyst-15 and SAC-13. For the continuous Jatropha BDF production, a steady 75-78wt% of fatty acid methyl ester (FAME) content was obtained over 15SA-SBA-15-p catalyst at 150°C for 75h, whereas the Amberlyst-15 and SAC-13 catalysts were quickly deactivated due to the decomposition of thermally unstable framework and serious leaching of sulfonic acids. More importantly, the quality, stability and cold flow characteristic of Jatropha BDF synthesized by 15SA-SBA-15-p catalyst were better than those synthesized by Amberlyst-15 and SAC-13 catalysts, making the blending with petro-diesel an easy task.

  2. Classification and identification of amino acids based on THz spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Ping J.; Ma, Ye H.; Li, Xian; Hou, Di B.; Cai, Jin H.; Zhang, Guang X.

    2015-11-01

    Amino acids are important nutrient substances for life, and many of them have several isomerides, while only L-type amino acids can be absorbed by body as nutrients. So it is certain worth to accurately classify and identify amino acids. In this paper, terahertz time-domain spectroscopy (THz-TDS) was used to detect isomers of various amino acids to obtain their absorption spectra, and their spectral characteristics were analyzed and compared. Results show that not all isomerides of amino acids have unique spectral characteristics, causing the difficulty of classification and identification. To solve this problem, partial least squares discriminant analysis (PLS-DA), firstly, was performed on extracting principal component of THz spectroscopy and classifying amino acids. Moreover, variable selection (VS) was employed to optimize spectral interval of feature extraction to improve analysis effect. As a result, the optimal classification model was determined and most samples can be accurately classified. Secondly, for each class of amino acids, PLS-DA combined with VS was also applied to identify isomerides. This work provides a suggestion for material classification and identification with THz spectroscopy.

  3. Development of polylactic acid-based materials through reactive modification

    NASA Astrophysics Data System (ADS)

    Fowlks, Alison Camille

    2009-12-01

    Polylactic acid (PLA)-based systems have shown to be of great potential for the development of materials requiring biobased content, biodegradation, and sufficient properties. The efforts in this study are directed toward addressing the current research need to overcome some of the inherent drawbacks of PLA. To meet this need, reactive extrusion was employed to develop new materials based on PLA by grafting, compounding, and polymer blending. In the first part of this work, maleic anhydride (MA) was grafted onto PLA by reactive extrusion. Two structurally different peroxides were used to initiate grafting and results were reported on the basis of grafting, molecular weight, and thermal behavior. An inverse relationship between degree of grafting and molecular weight was established. It was also found that, regardless of peroxide type, there is an optimum peroxid-to-MA ratio of 0.5:2 that promotes maximum grafting, beyond which degradation reactions become predominant. Overall, it was found that the maleated copolymer (MAPLA) could be used as an interfacial modifier in PLA-based composites. Therefore, MAPLA was incorporated into PLA-talc composites in varying concentrations. The influence of the MAPLA addition on the mechanical and thermal behavior was investigated. When added in an optimum concentration, MAPLA improved the tensile strength and crystallization of the composite. Furthermore, microscopic observation confirmed the compatibilization effect of MAPLA in PLA-talc composites. Vinyltrimethoxysilane was free-radically grafted onto the backbone of PLA and subsequently moisture crosslinked. The effects of monomer, initiator, and catalyst concentration on the degree of crosslinking and the mechanical and thermal properties were investigated. The presence of a small amount of catalyst showed to be a major contributor to the crosslinking formation in the time frame investigated, shown by an increase in gel content and decrease in crystallinity. Furthermore

  4. Local status and power in area-based health improvement partnerships.

    PubMed

    Powell, Katie; Thurston, Miranda; Bloyce, Daniel

    2014-11-01

    Area-based initiatives have formed an important part of public policy towards more socio-economically deprived areas in many countries. Co-ordinating service provision within and across sectors has been a common feature of these initiatives. Despite sustained policy interest in area-based initiatives, little empirical work has explored relations between area-based initiative providers, and partnership development within this context remains under-theorised. This article addresses both of these gaps by exploring partnerships as a social and developmental process, drawing on concepts from figurational sociology to explain how provider relations develop within an area-based initiative. Qualitative methods were used to explore, prospectively, the development of an area-based initiative targeted at a town in the north west of England. A central finding was that although effective delivery of area-based initiatives is premised on a high level of co-ordination between service providers, the pattern of interdependencies between providers limits the frequency and effectiveness of co-operation. In particular, the interdependency of area-based initiative providers with others in their organisation (what is termed here as 'organisational pull') constrained the ways in which they worked with providers outside of their own organisations. 'Local' status, which could be earned over time, enabled some providers to exert greater control over the way in which provider relations developed during the course of the initiative. These findings demonstrate how historically constituted social networks, within which all providers are embedded, shape partnership development. The theoretical insight developed here suggests a need for more realistic expectations among policymakers about how and to what extent provider partnerships can be managed.

  5. Local status and power in area-based health improvement partnerships.

    PubMed

    Powell, Katie; Thurston, Miranda; Bloyce, Daniel

    2014-11-01

    Area-based initiatives have formed an important part of public policy towards more socio-economically deprived areas in many countries. Co-ordinating service provision within and across sectors has been a common feature of these initiatives. Despite sustained policy interest in area-based initiatives, little empirical work has explored relations between area-based initiative providers, and partnership development within this context remains under-theorised. This article addresses both of these gaps by exploring partnerships as a social and developmental process, drawing on concepts from figurational sociology to explain how provider relations develop within an area-based initiative. Qualitative methods were used to explore, prospectively, the development of an area-based initiative targeted at a town in the north west of England. A central finding was that although effective delivery of area-based initiatives is premised on a high level of co-ordination between service providers, the pattern of interdependencies between providers limits the frequency and effectiveness of co-operation. In particular, the interdependency of area-based initiative providers with others in their organisation (what is termed here as 'organisational pull') constrained the ways in which they worked with providers outside of their own organisations. 'Local' status, which could be earned over time, enabled some providers to exert greater control over the way in which provider relations developed during the course of the initiative. These findings demonstrate how historically constituted social networks, within which all providers are embedded, shape partnership development. The theoretical insight developed here suggests a need for more realistic expectations among policymakers about how and to what extent provider partnerships can be managed. PMID:24695385

  6. Status and Prospects of ZnO-Based Resistive Switching Memory Devices.

    PubMed

    Simanjuntak, Firman Mangasa; Panda, Debashis; Wei, Kung-Hwa; Tseng, Tseung-Yuen

    2016-12-01

    In the advancement of the semiconductor device technology, ZnO could be a prospective alternative than the other metal oxides for its versatility and huge applications in different aspects. In this review, a thorough overview on ZnO for the application of resistive switching memory (RRAM) devices has been conducted. Various efforts that have been made to investigate and modulate the switching characteristics of ZnO-based switching memory devices are discussed. The use of ZnO layer in different structure, the different types of filament formation, and the different types of switching including complementary switching are reported. By considering the huge interest of transparent devices, this review gives the concrete overview of the present status and prospects of transparent RRAM devices based on ZnO. ZnO-based RRAM can be used for flexible memory devices, which is also covered here. Another challenge in ZnO-based RRAM is that the realization of ultra-thin and low power devices. Nevertheless, ZnO not only offers decent memory properties but also has a unique potential to be used as multifunctional nonvolatile memory devices. The impact of electrode materials, metal doping, stack structures, transparency, and flexibility on resistive switching properties and switching parameters of ZnO-based resistive switching memory devices are briefly compared. This review also covers the different nanostructured-based emerging resistive switching memory devices for low power scalable devices. It may give a valuable insight on developing ZnO-based RRAM and also should encourage researchers to overcome the challenges. PMID:27541816

  7. Status and Prospects of ZnO-Based Resistive Switching Memory Devices

    NASA Astrophysics Data System (ADS)

    Simanjuntak, Firman Mangasa; Panda, Debashis; Wei, Kung-Hwa; Tseng, Tseung-Yuen

    2016-08-01

    In the advancement of the semiconductor device technology, ZnO could be a prospective alternative than the other metal oxides for its versatility and huge applications in different aspects. In this review, a thorough overview on ZnO for the application of resistive switching memory (RRAM) devices has been conducted. Various efforts that have been made to investigate and modulate the switching characteristics of ZnO-based switching memory devices are discussed. The use of ZnO layer in different structure, the different types of filament formation, and the different types of switching including complementary switching are reported. By considering the huge interest of transparent devices, this review gives the concrete overview of the present status and prospects of transparent RRAM devices based on ZnO. ZnO-based RRAM can be used for flexible memory devices, which is also covered here. Another challenge in ZnO-based RRAM is that the realization of ultra-thin and low power devices. Nevertheless, ZnO not only offers decent memory properties but also has a unique potential to be used as multifunctional nonvolatile memory devices. The impact of electrode materials, metal doping, stack structures, transparency, and flexibility on resistive switching properties and switching parameters of ZnO-based resistive switching memory devices are briefly compared. This review also covers the different nanostructured-based emerging resistive switching memory devices for low power scalable devices. It may give a valuable insight on developing ZnO-based RRAM and also should encourage researchers to overcome the challenges.

  8. Effect of flaxseed on the fatty acid profile of egg yolk and antioxidant status of their neonatal offspring in Huoyan geese.

    PubMed

    Chen, W; Jiang, Y Y; Wang, J P; Yan, B X; Huang, Y Q; Wang, Z X

    2015-11-01

    The aim of this study was to evaluate the effects of geese's maternal diet supplemented with flaxseed on the fatty acid profiles of egg yolks and the antioxidant status of their offspring. A total of 288 female Huoyan geese (42 weeks old) were randomly allotted to four experimental groups in this 56-day experiment and fed on diets containing flaxseed at 0% (control), 5%, 10% and 15%, respectively. There were nine replicate pens per treatment, with eight geese per replicate pen. The concentration of α-linolenic acid (linear, P<0.01), EPA (20:5n-3; linear, P<0.01), DHA (22:6n-3; quadratic, P=0.03) and n-3 polyunsaturated fatty acid (PUFA) (linear, P<0.01) levels in the yolk lipids increased with increasing dietary flaxseed levels. Yolk palmitic acid (16:0, linear, P=0.05), saturated fatty acid (linear, P=0.04) level and total n-6/n-3 ratio (P<0.01) decreased in a linear fashion as dietary flaxseed levels increased. Increasing dietary flaxseed levels linearly decreased (P=0.01) the total cholesterol in egg yolks. After hatching, three 1-day-old gosling were selected randomly from each replicate to determine blood characteristics and liver antioxidant status. Aspartate aminotransferase activity (linear, P=0.03), total triglycerides (linear, P=0.02) and total cholesterol (linear, P=0.05) contents in blood linearly decreased as the levels of flaxseed increased. A linear dose response to maternal dietary flaxseed was detected for the activities of the goslings' liver enzymes catalase (linear, P=0.01), superoxide dismutase (linear, P<0.01) and glutathione peroxidase (linear, P<0.01). The malondialdehyde (quadratic, P=0.03) and alkaline phosphatase content in the livers of goslings decreased as flaxseed supplementation levels increased. In conclusion, the dietary addition of flaxseed up to 15%, in the maternal diet resulted in increased n-3 PUFA levels in egg yolks and improved the antioxidant status of offspring in a dose-dependent manner. PMID:26173627

  9. Unnatural amino acid mutagenesis-based enzyme engineering.

    PubMed

    Ravikumar, Yuvaraj; Nadarajan, Saravanan Prabhu; Yoo, Tae Hyeon; Lee, Chong-soon; Yun, Hyungdon

    2015-08-01

    Traditional enzyme engineering relies on substituting one amino acid by one of the other 19 natural amino acids to change the functional properties of an enzyme. However, incorporation of unnatural amino acids (UAAs) has been harnessed to engineer efficient enzymes for biocatalysis. Residue-specific and site-specific in vivo incorporation methods are becoming the preferred approach for producing enzymes with altered or improved functions. We describe the contribution of in vivo UAA incorporation methodologies to enzyme engineering as well as the future prospects for the field, including the integration of UAAs with other new advances in enzyme engineering.

  10. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    NASA Astrophysics Data System (ADS)

    Nan, Alexandrina; Bunge, Alexander; Turcu, Rodica

    2015-12-01

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  11. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    SciTech Connect

    Nan, Alexandrina Bunge, Alexander; Turcu, Rodica

    2015-12-23

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  12. Revegetation of extremely acid mine soils based on aided phytostabilization: A case study from southern China.

    PubMed

    Yang, Sheng-Xiang; Liao, Bin; Yang, Zhi-Hui; Chai, Li-Yuan; Li, Jin-Tian

    2016-08-15

    Acidification is a major constraint for revegetation of sulphidic metal-contaminated soils, as exemplified by the limited literature reporting the successful phytostabilization of mine soils associated with pH<3 and high acidification potential. In this study, a combination of ameliorants (lime and chicken manure) and five acid-tolerant plant species has been employed in order to establish a self-sustaining vegetation cover on an extremely acid (pH<3) polymetallic pyritic mine waste heap in southern China exhibiting high acidification potential. The results from the first two-year data showed that the addition of the amendments and the establishment of a plant cover were effective in preventing soil acidification. Net acid-generating potential of the mine soil decreased steadily, whilst pH and acid neutralization capacity increased over time. All the five acid-tolerant plants colonized successfully in the acidic metal-contaminated soil and developed a good vegetation cover within six months, and subsequent vegetation development enhanced organic matter accumulation and nutrient element status in the mine soil. The two-year remediation program performed on this extremely acid metalliferous soil indicated that aided phytostabilization can be a practical and effective restoration strategy for such extremely acid mine soils. PMID:27100018

  13. Acid-base site detection and mapping on solid surfaces by Kelvin force microscopy (KFM).

    PubMed

    Gouveia, Rubia F; Bernardes, Juliana S; Ducati, Telma R D; Galembeck, Fernando

    2012-12-01

    Electrostatic potential at the surface of acidic or basic solids changes under higher relative humidity (RH), as determined by using Kelvin force microscopy (KFM). The potential on acid surfaces becomes more negative as the water vapor pressure increases, while it becomes more positive on basic solids. These results verify the following hypothesis: OH(-) or H(+) ions associated with atmospheric water ion clusters are selectively adsorbed on solid surfaces, depending on the respective Brønsted acid or base character. Therefore, Kelvin microscopy, under variable humidity, is a rigorous but convenient alternative to determine the acid-base character of solid surfaces, with a great advantage: it uses only one amphoteric and simple reagent to determine both the acid and base sites. Moreover, this technique provides information on the spatial distribution of acid-base sites, which is currently inaccessible to any other method.

  14. In Vitro Investigation of Self-Assembled Nanoparticles Based on Hyaluronic Acid-Deoxycholic Acid Conjugates for Controlled Release Doxorubicin: Effect of Degree of Substitution of Deoxycholic Acid

    PubMed Central

    Wei, Wen-Hao; Dong, Xue-Meng; Liu, Chen-Guang

    2015-01-01

    Self-assembled nanoparticles based on a hyaluronic acid-deoxycholic acid (HD) chemical conjugate with different degree of substitution (DS) of deoxycholic acid (DOCA) were prepared. The degree of substitution (DS) was determined by titration method. The nanoparticles were loaded with doxorubicin (DOX) as the model drug. The human cervical cancer (HeLa) cell line was utilized for in vitro studies and cell cytotoxicity of DOX incorporated in the HD nanoparticles was accessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, cellular uptake of fluorescently labeled nanoparticles was also investigated. An increase in the degree of deoxycholic acid substitution reduced the size of the nanoparticles and also enhanced their drug encapsulation efficiency (EE), which increased with the increase of DS. A higher degree of deoxycholic acid substitution also lead to a lower release rate and an initial burst release of doxorubicin from the nanoparticles. In summary, the degree of substitution allows the modulation of the particle size, drug encapsulation efficiency, drug release rate, and cell uptake efficiency of the nanoparticles. The herein developed hyaluronic acid-deoxycholic acid conjugates are a good candidate for drug delivery and could potentiate therapeutic formulations for doxorubicin–mediated cancer therapy. PMID:25837468

  15. Nanoconjugate based on polymalic acid for tumor targeting.

    PubMed

    Ljubimova, Julia Y; Fujita, Manabu; Khazenzon, Natalya M; Lee, Bong-Seop; Wachsmann-Hogiu, Sebastian; Farkas, Daniel L; Black, Keith L; Holler, Eggehard

    2008-01-30

    A new prototype of polymer-derived drug delivery system, the nanoconjugate Polycefin, was tested for its ability to accumulate in tumors based on enhanced permeability and retention (EPR) effect and receptor mediated endocytosis. Polycefin was synthesized for targeted delivery of Morpholino antisense oligonucleotides into certain tumors. It consists of units that are covalently conjugated with poly(beta-l-malic acid) (M(w) 50,000, M(w)/M(n) 1.3) highly purified from cultures of myxomycete Physarum polycephalum. The units are active in endosomal uptake, disruption of endosomal membranes, oligonucleotide release in the cytoplasm, and protection against enzymatic degradation in the vascular system. The polymer is biodegradable, non-immunogenic and non-toxic. Polycefin was also coupled with AlexaFluor 680 C2-maleimide dye for in vivo detection. Nude mice received subcutaneous injections of MDA-MB 468 human breast cancer cells into the left posterior mid-dorsum or intracranial injections of human glioma cell line U87MG. Polycefin at concentration of 2.5mg/kg was injected via the tail vein. In vivo fluorescence tumor imaging was performed at different time points, 0-180 min up to 24h after the drug injection. The custom-made macro-illumination imaging MISTI system was used to examine the in vivo drug accumulation in animals bearing human breast and brain tumors. In breast tumors the fluorescence signal in large blood vessels and in the tumor increased rapidly until 60 min and remained in the tumor at a level 6 times higher than in non-tumor tissue (180 min) (p<0.003). In brain tumors drug accumulated selectively in 24h without any detectable signal in non-tumor areas. The results of live imaging were corroborated histologically by fluorescence microscopic examination of various organs. In addition to tumors, only kidney and liver showed some fluorescent signal.

  16. Highly efficient procedure for the synthesis of fructone fragrance using a novel carbon based acid.

    PubMed

    Hu, Baowei; Li, Chunqing; Zhao, Sheng-Xian; Rong, Lin-Mei; Lv, Shao-Qin; Liang, Xuezheng; Qi, Chenze

    2010-08-01

    The novel carbon based acid has been synthesized via one-step hydrothermal carbonization of furaldehyde and hydroxyethylsulfonic acid. A highly efficient procedure for the synthesis of fructone has been developed using the novel carbon based acid. The results showed that the catalyst possessed high activity for the reaction, giving a yield of over 95%. The advantages of high activity, stability, reusability and low cost for a simple synthesis procedure and wide applicability to various diols and beta-keto esters make this novel carbon based acid one of the best choices for the reaction.

  17. Bacteriophage-based therapy in cystic fibrosis-associated Pseudomonas aeruginosa infections: rationale and current status.

    PubMed

    Hraiech, Sami; Brégeon, Fabienne; Rolain, Jean-Marc

    2015-01-01

    Pulmonary infections involving Pseudomonas aeruginosa are among the leading causes of the deterioration of the respiratory status of cystic fibrosis (CF) patients. The emergence of multidrug-resistant strains in such populations, favored by iterative antibiotic cures, has led to the urgent need for new therapies. Among them, bacteriophage-based therapies deserve a focus. One century of empiric use in the ex-USSR countries suggests that bacteriophages may have beneficial effects against a large range of bacterial infections. Interest in bacteriophages has recently renewed in Western countries, and the in vitro data available suggest that bacteriophage-based therapy may be of significant interest for the treatment of pulmonary infections in CF patients. Although the clinical data concerning this specific population are relatively scarce, the beginning of the first large randomized study evaluating bacteriophage-based therapy in burn infections suggests that the time has come to assess the effectiveness of this new therapy in CF P. aeruginosa pneumonia. Consequently, the aim of this review is, after a brief history, to summarize the evidence concerning bacteriophage efficacy against P. aeruginosa and, more specifically, the in vitro studies, animal models, and clinical trials targeting CF.

  18. The status of school-based nutrition education at the state agency level.

    PubMed

    Shannon, B; Mullis, R; Bernardo, V; Ervin, B; Poehler, D L

    1992-03-01

    The status of school-based nutrition education at the state agency level was examined. Telephone interviews with agencies in all 50 states revealed that nine states mandated nutrition be taught and another 21 included nutrition as a required topic in mandated subjects, frequently health. The other states had initiatives to promote school-based nutrition education but it was not required. Published requirements for teacher certification in elementary education, home economics, and health education seldom (two to three states) specified nutrition as a requirement. However, follow-up investigations revealed many states indirectly promote nutrition preparation for home economics and health education teachers through guidelines for approval of college programs in these areas. An inventory of nutrition education curricular materials revealed they were most frequently directed to grades K-6 and focused mainly on general foods and nutrition or that related to health. Given the links that emerged between health and nutrition, incorporating nutrition into health education may help promote school-based nutrition education.

  19. Bacteriophage-based therapy in cystic fibrosis-associated Pseudomonas aeruginosa infections: rationale and current status

    PubMed Central

    Hraiech, Sami; Brégeon, Fabienne; Rolain, Jean-Marc

    2015-01-01

    Pulmonary infections involving Pseudomonas aeruginosa are among the leading causes of the deterioration of the respiratory status of cystic fibrosis (CF) patients. The emergence of multidrug-resistant strains in such populations, favored by iterative antibiotic cures, has led to the urgent need for new therapies. Among them, bacteriophage-based therapies deserve a focus. One century of empiric use in the ex-USSR countries suggests that bacteriophages may have beneficial effects against a large range of bacterial infections. Interest in bacteriophages has recently renewed in Western countries, and the in vitro data available suggest that bacteriophage-based therapy may be of significant interest for the treatment of pulmonary infections in CF patients. Although the clinical data concerning this specific population are relatively scarce, the beginning of the first large randomized study evaluating bacteriophage-based therapy in burn infections suggests that the time has come to assess the effectiveness of this new therapy in CF P. aeruginosa pneumonia. Consequently, the aim of this review is, after a brief history, to summarize the evidence concerning bacteriophage efficacy against P. aeruginosa and, more specifically, the in vitro studies, animal models, and clinical trials targeting CF. PMID:26213462

  20. Importance of acid-base equilibrium in electrocatalytic oxidation of formic acid on platinum.

    PubMed

    Joo, Jiyong; Uchida, Taro; Cuesta, Angel; Koper, Marc T M; Osawa, Masatoshi

    2013-07-10

    Electro-oxidation of formic acid on Pt in acid is one of the most fundamental model reactions in electrocatalysis. However, its reaction mechanism is still a matter of strong debate. Two different mechanisms, bridge-bonded adsorbed formate mechanism and direct HCOOH oxidation mechanism, have been proposed by assuming a priori that formic acid is the major reactant. Through systematic examination of the reaction over a wide pH range (0-12) by cyclic voltammetry and surface-enhanced infrared spectroscopy, we show that the formate ion is the major reactant over the whole pH range examined, even in strong acid. The performance of the reaction is maximal at a pH close to the pKa of formic acid. The experimental results are reasonably explained by a new mechanism in which formate ion is directly oxidized via a weakly adsorbed formate precursor. The reaction serves as a generic example illustrating the importance of pH variation in catalytic proton-coupled electron-transfer reactions.