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Sample records for acid base status

  1. 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.

  2. Nutrition, acid-base status and growth in early childhood.

    PubMed

    Kalhoff, H; Manz, F

    2001-10-01

    Optimal growth is only possible in a well-balanced "inner milieu". Premature infants are especially vulnerable for disturbances of acid-base metabolism with a predisposition to metabolic acidosis due to a transient disproportion between age-related low renal capacity for net acid excretion (NAE) and an unphysiologically high actual renal NAE on nutrition with standard formulas. During a 50 month period, 452 low birth-weight infants were screened for spontaneous development of incipient late metabolic acidosis (ILMA), an early stage during the development of retention acidosis, characterized by maximum renal acid stimulation (MRAS, urine-pH < 5.4) on two consecutive days but still compensated systemic acid-base status. Compared with controls, patients with ILMA showed higher serum creatinine values, an increased urinary excretion of sodium, aldosterone and nitrogen, but only slightly lower blood pH (7.38 vs 7.41) and base excess (-2.8 vs. 0.2 mmol/l) with respiratory compensation (PCO2 35 vs 37 mm Hg). Patients with altogether 149 episodes of ILMA were subsequently randomly allocated to either treatment with NaHCO3 2 mmol/kg/d for 7 days or no special therapy in protocol I, or NaHCO3 vs NaCl each 2 mmol/kg/d for 7 days in protocol II. Patients of protocol I with persistent MRAS for 7 days showed lowest weight gain and a tendency for a further increase in urinary aldosterone and nitrogen excretion. NaCl supplementation (protocol II) seemed to promote weight gain without affecting either impaired mineralization or suboptimal nitrogen retention. Patients with alkali therapy under both protocols showed normal weight gain and normalization of hormonal stimulation, mineralization (protocol II) and nitrogen assimilation. Modification of the mineral content of a standard preterm formula decreased renal NAE to the low level seen on alimentation with human milk and reduced the incidence of ILMA in preterm and small-for-gestational-age infants to 1%. The data show that ILMA is

  3. Kinematic variables and blood Acid-base status in the analysis of collegiate swimmers' anaerobic capacity.

    PubMed

    Bielec, G; Makar, P; Laskowski, R; Olek, R A

    2013-09-01

    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.

  4. 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.

  5. Control of rectal gland secretion by blood acid-base status in the intact dogfish shark (Squalus acanthias).

    PubMed

    Wood, Chris M; Munger, R Stephen; Thompson, Jill; Shuttleworth, Trevor J

    2007-05-14

    In order to address the possible role of blood acid-base status in controlling the rectal gland, dogfish were fitted with indwelling arterial catheters for blood sampling and rectal gland catheters for secretion collection. In intact, unanaesthetized animals, isosmotic volume loading with 500 mmol L-1 NaCl at a rate of 15 mL kg-1 h-1 produced a brisk, stable rectal gland secretion flow of about 4 mL kg-1 h-1. Secretion composition (500 mmol L-1 Na+ and Cl-; 5 mmol L-1 K+; <1 mmol L-1 Ca2+, Mg2+, SO(4)2-, or phosphate) was almost identical to that of the infusate with a pH of about 7.2, HCO3- mmol L-1<1 mmol L-1 and a PCO2 (1 Torr) close to PaCO2. Experimental treatments superimposed on the infusion caused the expected disturbances in systemic acid-base status: respiratory acidosis by exposure to high environmental PCO2, metabolic acidosis by infusion of HCl, and metabolic alkalosis by infusion of NaHCO3. Secretion flow decreased markedly with acidosis and increased with alkalosis, in a linear relationship with extracellular pH. Secretion composition did not change, apart from alterations in its acid-base status, and made negligible contribution to overall acid-base balance. An adaptive control of rectal gland secretion by systemic acid-base status is postulated-stimulation by the "alkaline tide" accompanying the volume load of feeding and inhibition by the metabolic acidosis accompanying the volume contraction of exercise.

  6. 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.

  7. 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.

  8. 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.

  9. Prediction of solute kinetics, acid-base status, and blood volume changes during profiled hemodialysis.

    PubMed

    Ursino, M; Colí, L; Brighenti, C; Chiari, L; de Pascalis, A; Avanzolini, G

    2000-02-01

    A mathematical model of solute kinetics oriented to the simulation of hemodialysis is presented. It includes a three-compartment model of body fluids (plasma, interstitial and intracellular), a two-compartment description of the main solutes (K+, Na+, Cl-, urea, HCO3-, H+), and acid-base equilibrium through two buffer systems (bicarbonate and noncarbonic buffers). Tentative values for the main model parameters can be given a priori, on the basis of body weight and plasma concentration values measured before beginning the session. The model allows computation of the amount of sodium removed during hemodialysis, and may enable the prediction of plasma volume and osmolarity changes induced by a given sodium concentration profile in the dialysate and by a given ultrafiltration profile. Model predictions are compared with clinical data obtained during 11 different profiled hemodialysis sessions, both with all parameters assigned a priori, and after individual estimation of dialysances and mass-transfer coefficients. In most cases, the agreement between the time pattern of model solute concentrations in plasma and clinical data was satisfactory. In two sessions, blood volume changes were directly measured in the patient, and in both cases the agreement with model predictions was acceptable. The present model can be used to improve the dialysis session taking some characteristics of individual patients into account, in order to minimize intradialytic unbalances (such as hypotension or disequilibrium syndrome).

  10. Effects of dietary cation-anion difference on the acid-base status of dry cows.

    PubMed

    Vagnoni, D B; Oetzel, G R

    1998-06-01

    Responses in dry matter intake (DMI) and acidbase balance to three sources of anionic salts (dietary cation-anion difference = -63 to -40 meq/kg of dry matter), an acidified fermentation by-product, MgSO4.7H2O + NH4Cl, and MgSO4.7H2O + CaCl2.2H2O + CaSO4, were evaluated relative to the responses of cows fed a control diet (dietary cationanion difference = 203 meq/kg of dry matter) that did not contain anionic salts. Diets were fed for 1-wk periods to eight nonlactating Holsteins assigned to two replicated 4 x 4 Latin squares. Daily DMI increased as time of access to the diet increased up to d 5; mean DMI over d 5 to 7 was reduced by dietary anionic salts. Diets containing anionic salts induced a mild metabolic acidosis that was completely compensated by nonrespiratory mechanisms (decreased blood bicarbonate and base excess; pCO2 and pH values were unaffected). Urinary pH values and bicarbonate excretion were reduced, and urinary NH4+ and titratable acidity excretion were increased, for cows fed diets containing anionic salts. Strong ion difference in urine was decreased by dietary anionic salts because of the relatively greater excretions of Cl- and S2- versus Na+ and K+ by cows fed these diets. Dietary anionic salts decreased mean ruminal pH by 0.12 units, possibly because of the reduced strong ion difference of ruminal fluid. Dietary anionic salts increased mean ruminal NH3 concentration by 2.2 mM, probably because of the higher nonprotein N content of these diets. The strong negative relationship (r2 = 0.95) between urinary pH and net acid excretion by cows fed the diets containing anionic salts suggested that urinary pH measurement might be a useful tool to assess the degree of metabolic acidosis that was imposed by dietary anionic salts.

  11. The effects of walking on heart rate, ventilation rate and acid-base status in the lobster homarus americanus

    PubMed

    Rose; Wilkens; Walker

    1998-09-01

    American lobsters Homarus americanus were exercised on an underwater treadmill at speeds from 1.7 to 8 m min-1 to determine the effects of exercise on heart rate, ventilation rate and acid-base status. Heart and ventilation rates showed almost instantaneous increases at the start of exercise, but the magnitude of the increase was not related to speed. Maximum heart rate was approximately 80-90 beats min-1 and maximum ventilation rate was 175-180 beats min-1 at all speeds tested. Exercise at all speeds caused a decrease in haemolymph pH, with the acidosis after exercise at 8 m min-1 being significantly greater than at the other three speeds. Concomitant with this acidosis was a large increase in partial pressure of carbon dioxide, with the largest increase occurring after exercise at 8 m min-1. The concentration of lactate in the haemolymph increased to similar levels at all speeds of walking. Davenport analysis indicates that the acidosis was predominantly respiratory in nature. Although it was anticipated that heart and ventilation rates would show increases proportional to the speed of exercise, this was not the case. Rather, the responses were fixed regardless of walking speed. The reason for this phenomenon remains unexplained.

  12. 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

  13. [Effect of polymer material thermal destruction products on external respiration and acid-base status of blood].

    PubMed

    Tavolzhanova, T I; Rozova, K V

    2004-01-01

    In experiments on white laboratory rats the influence of fluor-, cyan- and sulfur-containing gaseous products, formed under thermodestruction of synthetic materials in normal and high environmental temperature on external respiration and some parameters of acid-base blood values was investigated. It was shown, that external respiration, due to considerable it depression, could not compensate neither hypoxic state, accompanied by hypoxemia, nor hypercapnia and acidosis, developed under the influence of toxic agents both in normal environmental temperature and in hyperthermia.

  14. Effects of environmental heat and intake of tall fescue seed infested with Acremonium coenophialum on the acid-base status of young bulls.

    PubMed

    Wallace, L L; Vogt, D W; Lipsey, R J; Garner, G B; Cornell, C N

    1996-04-01

    Effects of high environmental temperature and dietary intake of tall fescue (Festuca arundinacea) seed containing the endophyte Acremonium coenophialum on bovine acid-base status were studied using 3 groups of bull calves (2 Simmental, 1 Angus). Experimental animals were housed in controlled-climate chambers and subjected to gradual increases in environmental temperature, first while being fed an endophyte-free diet and then while being fed a diet containing 17% endophyte-infested fescue seed. Marked acid-base disturbances were not observed in any animals. In general, Pco2, HCO3-, base excess, and arterial blood pH values were reduced in response to heat stress, both with endophyte-free and endophyte-containing diets. In most individuals anion gap increased. These results reflected metabolic compensation for mild chronic alveolar hyperventilation and retention of organic acids. These findings suggest that, under conditions similar to those found during the summer in central Missouri, normal cattle should not be at great risk of developing respiratory alkalosis or other severe acid-base disturbances as a result of heat stress and/or intake of tall fescue endophyte.

  15. Seasonal changes in blood oxygen transport and acid-base status in the tegu lizard, Tupinambis merianae.

    PubMed

    Andrade, Denis V; Brito, Simone P; Toledo, Luís Felipe; Abe, Augusto S

    2004-05-20

    Oxygen-binding properties, blood gases, and acid-base parameters were studied in tegu lizards, Tupinambis merianae, at different seasons and temperatures. Independent of temperature and pH, blood oxygen affinity was higher in dormant lizards than in those active during the summer. Haematocrit (Hct) and hemoglobin content ([Hb]) were greater in active lizards resulting in a higher oxygen-carrying capacity. Nucleoside triphosphate content ([NTP]) was reduced during dormancy, but the ratio between [NTP] and [Hb] remained unchanged. Dormancy was accompanied by an increase in plasma bicarbonate ([HCO-(3)]pl) and an elevation of arterial CO2 partial pressure (PaCO2) and CO2 content in the plasma (CplCO2). These changes in acid-base parameters persist over a broad range of body temperatures. In vivo, arterial O2 partial pressure (PaO2) and O2 content (CaO2) were not affected by season and tended to increase with temperature. Arterial pH (pHa) of dormant animals is reduced compared to active lizards at body temperatures below 15 degrees C, while no significant difference was noticed at higher temperatures.

  16. 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

  17. Modelling interactions of acid-base balance and respiratory status in the toxicity of metal mixtures in the American oyster Crassostrea virginica.

    PubMed

    Macey, Brett M; Jenny, Matthew J; Williams, Heidi R; Thibodeaux, Lindy K; Beal, Marion; Almeida, Jonas S; Cunningham, Charles; Mancia, Annalaura; Warr, Gregory W; Burge, Erin J; Holland, A Fred; Gross, Paul S; Hikima, Sonomi; Burnett, Karen G; Burnett, Louis; Chapman, Robert W

    2010-03-01

    Heavy metals, such as copper, zinc and cadmium, represent some of the most common and serious pollutants in coastal estuaries. In the present study, we used a combination of linear and artificial neural network (ANN) modelling to detect and explore interactions among low-dose mixtures of these heavy metals and their impacts on fundamental physiological processes in tissues of the Eastern oyster, Crassostrea virginica. Animals were exposed to Cd (0.001-0.400 microM), Zn (0.001-3.059 microM) or Cu (0.002-0.787 microM), either alone or in combination for 1 to 27 days. We measured indicators of acid-base balance (hemolymph pH and total CO(2)), gas exchange (Po(2)), immunocompetence (total hemocyte counts, numbers of invasive bacteria), antioxidant status (glutathione, GSH), oxidative damage (lipid peroxidation; LPx), and metal accumulation in the gill and the hepatopancreas. Linear analysis showed that oxidative membrane damage from tissue accumulation of environmental metals was correlated with impaired acid-base balance in oysters. ANN analysis revealed interactions of metals with hemolymph acid-base chemistry in predicting oxidative damage that were not evident from linear analyses. These results highlight the usefulness of machine learning approaches, such as ANNs, for improving our ability to recognize and understand the effects of sub-acute exposure to contaminant mixtures.

  18. 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.

  19. Studies on the extra- and intracellular acid-base status and its role on metabolic depression in the land snail Helix lucorum (L.) during estivation.

    PubMed

    Michaelidis, B

    2002-05-01

    The aim of the present study was to examine the acid-base status of extra- and intracellular fluids and its possible role on the regulation of the metabolic rate of Helix lucorum during prolonged estivation. For this purpose, the rate of oxygen consumption for active and estivating snails was determined. The acid-base status was also examined in the hemolymph and tissues from active and estivating snails acclimated at 25 degrees C. In addition, the buffer values of hemolymph and tissues were determined in order to examine whether there is a change in the snails during estivation. The rate of oxygen consumption decreased significantly within the 1st 10 days of estivation from 122.51+/-10 microl.g(-1).h(-1) to 25.86+/-5.2 microl.g(-1).h(-1), indicating a marked decrease in metabolic rate. P(CO2)increased within the 1st 20 days of estivation from 13.52+/-0.68 mmHg to 25.09+/-2.05 mmHg, while the pH of hemolymph (pH(e)) decreased from 7.72+/-0.04 to 7.44+/-0.06. The level of bicarbonates decreased in the hemolymph of estivating snails, indicating a metabolic acidosis, which was moderate in extracellular fluids. In contrast to pH(e), the intracellular pH (pH(i)) was maintained in the tissues of estivating H. lucorum, indicating a regulation of pH(i) despite the developed hypercapnia. According to the results presented here, it seems that the timing of pH(e) changes does not correlate with the timing of metabolic rate reduction in estivating H. lucorum.

  20. Effects of Different Oral Doses of Sodium Chloride on the Basal Acid-Base and Mineral Status of Exercising Horses Fed Low Amounts of Hay

    PubMed Central

    Zeyner, Annette; Romanowski, Kristin; Vernunft, Andreas; Harris, Patricia; Müller, Ann-Marie; Wolf, Carola; Kienzle, Ellen

    2017-01-01

    The provision of NaCl, according to current recommendations, to horses in moderate work has been shown to induce immediate postprandial acidosis. The present study aimed to clarify whether this NaCl induced acidosis i) persists beyond the immediate postprandial period, and ii) is still present after a 2 week adaptation period. Six adult warmblood mares in moderate work received daily 1.00 kg hay per 100 kg body weight (bwt) only together with 0.64 kg unprocessed cereal grains/100 kg bwt.d as fed basis. Using a 3x3 Latin Square, either 0 (NaCl-0), 50 (NaCl-50) or 100 (NaCl-100) g NaCl/d were fed together with the concentrates in two equal doses for 3 weeks. During the final week, a mineral digestibility trial was undertaken. The middle sodium and chloride intake (NaCl-50) at least met the most common recommendations for moderate work. Morning (7:00 AM) urine and venous blood samples were collected on days 0, 1–4, 8, and 15, and analysed for pH, acid-base status, creatinine and electrolyte concentrations. Fractional electrolyte clearances (FC) were determined. Mean apparent sodium digestibility ranged between 60–62% whereas chloride digestibility was consistently above 94%. Supplementing 100 g but not 50 g of NaCl resulted in significant reduction of blood pH and base excess as well as urinary pH and urine acid excretion. Both 50 g and 100 g NaCl supplementation caused a significant reduction in base and net acid-base excretion, urine density and potassium concentration, but increased urine sodium concentration and the FC of sodium and chloride (P < 0.05). This suggests that a high proportion of the recommended salt doses is excreted renally. The above effects of NaCl supplementation persisted over the 2 week measurement period. Results suggest that feeding 100 g NaCl to moderately exercising horses results in mild metabolic acidosis, whereas feeding 50 g according to current recommendations resulted in compensated acidosis. PMID:28045916

  1. 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

  2. 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…

  3. Impact of Plasma-Lyte pH 7.4 on acid-base status and hemodynamics in a model of controlled hemorrhagic shock

    PubMed Central

    Noritomi, Danilo Teixeira; Pereira, Adriano José; Bugano, Diogo Diniz Gomes; Rehder, Paulo Sergio; Silva, Eliézer

    2011-01-01

    OBJECTIVE: Intravenous infusion of crystalloid solutions is a cornerstone of the treatment of hemorrhagic shock. However, crystalloid solutions can have variable metabolic acid-base effects, perpetuating or even aggravating shock-induced metabolic acidosis. The aim of this study was to compare, in a controlled volume–driven porcine model of hemorrhagic shock, the effects of three different crystalloid solutions on the hemodynamics and acid-base balance. METHODS: Controlled hemorrhagic shock (40% of the total blood volume was removed) was induced in 18 animals, which were then treated with normal saline (0.9% NaCl), Lactated Ringer's Solution or Plasma-Lyte pH 7.4, in a blinded fashion (n = 6 for each group). Using a predefined protocol, the animals received three times the volume of blood removed. RESULTS: The three different crystalloid infusions were equally capable of reversing the hemorrhage-induced low cardiac output and anuria. The Lactated Ringer's Solution and Plasma-Lyte pH 7.4 infusions resulted in an increased standard base excess and a decreased serum chloride level, whereas treatment with normal saline resulted in a decreased standard base excess and an increased serum chloride level. The Plasma-Lyte pH 7.4 infusions did not change the level of the unmeasured anions. CONCLUSION: Although the three tested crystalloid solutions were equally able to attenuate the hemodynamic and tissue perfusion disturbances, only the normal saline induced hyperchloremia and metabolic acidosis. PMID:22086530

  4. 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.

  5. Blood Gas and Acid-Base Status of Conscious Pigs Subjected to Fixed- Volume Hemorrhage and Resuscitated with Hypertonic Saline Dextran

    DTIC Science & Technology

    1990-01-01

    This dIcurnent has been appro fLr p .,blis ’ c ~ and sale; its 1da.stnbution is unimitedL Circulatory Shock 32:19-29 (1990) AD-A233 250 Blood Gas and...volume. Blood gas and acid-base measurements were made at 38.5° C , the normal core temperature of domestic pigs [5], immediately after sample removal...hemorrhagic hypotension in the piglet. Pediatr Res 17:77-80, 1983. 15. Matsuda H, Raja TNK, Maeta H, John E, Fornel L, Vidyasagar D: Effect of acute

  6. [Stewart's acid-base approach].

    PubMed

    Funk, Georg-Christian

    2007-01-01

    In addition to paCO(2), Stewart's acid base model takes into account the influence of albumin, inorganic phosphate, electrolytes and lactate on acid-base equilibrium. It allows a comprehensive and quantitative analysis of acid-base disorders. Particularly simultaneous and mixed metabolic acid-base disorders, which are common in critically ill patients, can be assessed. Stewart's approach is therefore a valuable tool in addition to the customary acid-base approach based on bicarbonate or base excess. However, some chemical aspects of Stewart's approach remain controversial.

  7. Evidence of inadequate docosahexaenoic acid status in Brazilian pregnant and lactating women.

    PubMed

    Torres, Alexandre G; Trugo, Nádia M F

    2009-04-01

    Recently published data concerning dietary intake of fat and food sources of (n-3) long-chain polyunsaturated fatty acids (LCPUFA) in Brazil are reviewed together with data on biochemical indices of PUFA status during pregnancy and lactation and PUFA composition of breast milk in Brazilian adolescents and adults. Potential inadequacies of docosahexaenoic acid (DHA) status among Brazilian pregnant and lactating women have not yet been thoroughly evaluated. The data reviewed show that dietary intake of food sources of n-3 LCPUFA is low and possibly deficient in Brazil, and that biochemical indices of maternal DHA status and breast milk DHA content are low compared to the international literature. These data indicate inadequate DHA status among Brazilian women during pregnancy and lactation, but this evidence needs confirmation through comprehensive and specific population-based studies.

  8. Alterations in amino acid status in cats with feline dysautonomia

    PubMed Central

    Symonds, Herb W.; Knottenbelt, Clare; Cave, Tom A.; MacDonald, Susan J.; Stratton, Joanna; Leon, Irene; Turner, Judith A.; Pirie, R. Scott

    2017-01-01

    Feline dysautonomia (FD) is a multiple system neuropathy of unknown aetiology. An apparently identical disease occurs in horses (equine grass sickness, EGS), dogs, rabbits, hares, sheep, alpacas and llamas. Horses with acute EGS have a marked reduction in plasma concentrations of the sulphur amino acids (SAA) cyst(e)ine and methionine, which may reflect exposure to a neurotoxic xenobiotic. The aim of this study was to determine whether FD cats have alterations in amino acid profiles similar to those of EGS horses. Amino acids were quantified in plasma/serum from 14 FD cats, 5 healthy in-contact cats which shared housing and diet with the FD cats, and 6 healthy control cats which were housed separately from FD cats and which received a different diet. The adequacy of amino acids in the cats’ diet was assessed by determining the amino acid content of tinned and dry pelleted foods collected immediately after occurrences of FD. Compared with controls, FD cats had increased concentrations of many essential amino acids, with the exception of methionine which was significantly reduced, and reductions in most non-essential amino acids. In-contact cats also had inadequate methionine status. Artefactual loss of cysteine during analysis precluded assessment of the cyst(e)ine status. Food analysis indicated that the low methionine status was unlikely to be attributable to dietary inadequacy of methionine or cystine. Multi-mycotoxin screening identified low concentrations of several mycotoxins in dry food from all 3 premises. While this indicates fungal contamination of the food, none of these mycotoxins appears to induce the specific clinico-pathologic features which characterise FD and equivalent multiple system neuropathies in other species. Instead, we hypothesise that ingestion of another, as yet unidentified, dietary neurotoxic mycotoxin or xenobiotic, may cause both the characteristic disease pathology and the plasma SAA depletion. PMID:28333983

  9. Arterial acid-base status during digestion and following vascular infusion of NaHCO(3) and HCl in the South American rattlesnake, Crotalus durissus.

    PubMed

    Arvedsen, Sine K; Andersen, Johnnie B; Zaar, Morten; Andrade, Denis; Abe, Augusto S; Wang, Tobias

    2005-12-01

    Digestion is associated with gastric secretion that leads to an alkalinisation of the blood, termed the "alkaline tide". Numerous studies on different reptiles and amphibians show that while plasma bicarbonate concentration ([HCO(3)(-)](pl)) increases substantially during digestion, arterial pH (pHa) remains virtually unchanged, due to a concurrent rise in arterial PCO(2) (PaCO(2)) caused by a relative hypoventilation. This has led to the suggestion that postprandial amphibians and reptiles regulate pHa rather than PaCO(2). Here we characterize blood gases in the South American rattlesnake (Crotalus durissus) during digestion and following systemic infusions of NaHCO(3) and HCl in fasting animals to induce a metabolic alkalosis or acidosis in fasting animals. The magnitude of these acid-base disturbances were similar in magnitude to that mediated by digestion and exercise. Plasma [HCO(3)(-)] increased from 18.4+/-1.5 to 23.7+/-1.0 mmol L(-1) during digestion and was accompanied by a respiratory compensation where PaCO(2) increased from 13.0+/-0.7 to 19.1+/-1.4 mm Hg at 24 h. As a result, pHa decreased slightly, but were significantly below fasting levels 36 h into digestion. Infusion of NaHCO(3) (7 mmol kg(-1)) resulted in a 10 mmol L(-1) increase in plasma [HCO(3)(-)] within 1 h and was accompanied by a rapid elevation of pHa (from 7.58+/-0.01 to 7.78+/-0.02). PaCO(2), however, did not change following HCO(3)(-) infusion, which indicates a lack of respiratory compensation. Following infusion of HCl (4 mmol kg(-1)), plasma pHa decreased by 0.07 units and [HCO(3)(-)](pl) was reduced by 4.6 mmol L(-1) within the first 3 h. PaCO(2), however, was not affected and there was no evidence for respiratory compensation. Our data show that digesting rattlesnakes exhibit respiratory compensations to the alkaline tide, whereas artificially induced metabolic acid-base disturbances of same magnitude remain uncompensated. It seems difficult to envision that the central and

  10. Effects of the inclusion of sodium bicarbonate and sugar beet pulp in the concentrate for fattening lambs on acid-base status and meat characteristics.

    PubMed

    Bodas, R; Rodríguez, A B; López, S; Fernández, B; Mantecón, A R; Giráldez, F J

    2007-12-01

    Thirty-six young Merino lambs (15.3kg live weight) were allocated into four equal groups to study the effects of the inclusion of sodium bicarbonate ('Bic', 0 vs. 2%) and sugar beet pulp ('SBP', 0 vs. 12%) in the concentrate on meat characteristics. Lambs were fed barley straw and concentrate ad libitum. When they reached 25kg a blood sample was taken and the animal slaughtered. After 24h meat characteristics (pH, colour, water holding capacity, Warner-Bratzler shear force, chemical and fatty acid - 'FA' - composition) were measured on M. longissimus thoracis et lumborum. SBP replacing 24% of the barley in the concentrate caused an increase in shear force (P<0.05) and saturated FA (P<0.05), decreasing meat unsaturated FA (P<0.05). SB increased blood base excess (P<0.05) and meat yellowness (P<0.05) and decreased meat pH (P<0.05), without altering any other meat characteristics.

  11. Effects of copper sources and dietary cation-anion balance on copper availability and acid-base status in dairy calves.

    PubMed

    Xin, Z; Waterman, D F; Hemken, R W; Harmon, R J; Jackson, J A

    1991-09-01

    Twenty-four Holstein and Jersey calves (14 Holstein), 4 to 11 d of age, were assigned randomly to six treatments in a 2 x 3 factorial arrangement to examine the effects of Cu sources and dietary cation-anion balance on Cu availability and acid-base balance. Treatments were cationic basal diet (20 meq of dietary cation-anion balance on a DM basis), cationic basal diet supplemented with CuO, cationic basal diet supplemented with CuSO4, anionic basal diet (-10 meq), anionic basal diet supplemented with CuO, and anionic basal diet supplemented with CuSO4. Copper sources did not show any effect on growth of calves. The cationic diet increased calf growth compared with the anionic diet at wk 12 of the experiment. Blood pH was increased by the cationic diet in comparison with the anionic diet at wk 8 and 12. Blood pH also was increased by CuSO4 compared with CuO treatment in the early period of the treatment. Blood bicarbonate concentration was decreased by CuO and the anionic diet. Interactions between Cu sources and cation-anion balance were found for blood pH and bicarbonate concentration. Liver Cu concentration was increased by CuSO4 but not by CuO supplementation compared with control. Therefore, CuSO4 was found to be highly available, whereas CuO was a very poorly available source of Cu for young calves.

  12. Current status of iron-based superconductors

    NASA Astrophysics Data System (ADS)

    Kamihara, Yoichi

    2012-03-01

    Current status of iron-based superconductors is summarized. Although short range magnetic ordering and magnetic phase separation of Fe are controversial, (long range) magnetic and electronic phase diagrams of iron based superconductors can be classified into two-type. Antiferromagnetic ordering of itinerant Fe does not coexist with superconducting phase of SmFeAsO1 - xFx. The very large H c2 of iron-based superconductors attract us to attempts at applications.

  13. 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.

  14. 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

    2014-09-12

    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.

  15. 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.

  16. Essential and long-chain polyunsaturated fatty acid status and fatty acid composition of breast milk of lactating adolescents.

    PubMed

    Meneses, Flávia; Torres, Alexandre G; Trugo, Nádia M F

    2008-11-01

    The aims of the present study were to evaluate essential fatty acids (EFA) and long-chain PUFA (LCPUFA) status in lactating adolescents and its association with breast milk composition. Healthy nursing adolescents from Rio de Janeiro, Brazil (n 30; 14-19 years; 30-120 d postpartum), exclusively or predominantly breast-feeding, participated in this study. Breast milk and blood samples were collected after overnight fasting. Fatty acid composition of breast milk, erythrocyte membrane (EM) and plasma NEFA were determined by GC. Indices of fatty acid status (mean melting point (MMP); EFA status index; DHA status indices, 22 : 5n-6:22 : 4n-6 and 22 : 6n-3:22 : 5n-6 ratios) were calculated from EM fatty acid composition. Dietary intake of n-3 fatty acids was low when compared with current recommendations for lactating women. MMP was associated with indices of DHA status, some individual fatty acids in EM and years post-menarche and weeks postpartum, suggesting the use of erythrocyte MMP as a possible comprehensive biochemical marker of LCPUFA status in this physiological condition. The DHA status of lactating adolescents and their milk DHA concentrations were similar to the values of Brazilian lactating adults, but lower compared with the values of lactating adults from other countries. Therefore, these lactating adolescents were apparently not disadvantaged, as compared with the Brazilian adults, when EM and breast milk fatty acid composition were considered. In general, PUFA in milk from adolescents presented few associations with their concentrations in plasma NEFA and with maternal status. However, milk DHA was associated with maternal LCPUFA and DHA states.

  17. Fatty acid composition of the red blood cell membrane in relation to menopausal status.

    PubMed

    Tworek; Muti; Micheli; Krogh; Riboli; Berrino

    2000-10-01

    PURPOSE: Menopausal status effects female anatomical functioning at a variety of system-wide and cellular levels, including cellular membrane composition. This study analyzed a nested case-control ORDET data set of 433 pre and post-menopausal breast cancer controls to examine the effects of menopausal status on the fatty acid composition of the red blood cell membrane.METHODS: ORDET is a prospective cohort study conducted in Italy to investigate the etiologic role of hormones and diet in breast cancer development. The fatty acid composition was measured and analyzed by gas chromotography, comparing retention time with standard measurement. Twenty-two individual fatty acids were measured, recorded, and categorized into four fatty acid groups: saturated, monounsaturated, polyunsaturated n-6 (PUFA n-6), and polyunsaturated (PUFA n-3) fatty acids.RESULTS: Post-menopausal women had consistently lower mean values for all four fatty acid categories and all individual fatty acids. Statistically significant mean differences, by menopausal status, were observed for three of the four fatty acid categories: saturated fatty acids (p = 0.006), PUFA n-6 acids (p = 0.001), and PUFA n-3 acids (p = 0.000). The biggest statistically significant differences in mean values among individual fatty acids for each category were observed for Palmitic acid (p = 0.009), Oleic acid (p = 0.040), Linoleic acid (p = 0.000), and Docosahexaenoic acid (p = 0.000). Individual fatty acids were also less highly correlated among post-menopausal women.CONCLUSIONS: There was an observed relationship between menopausal status and the fatty acid composition of the red blood cell membrane that warrants further study. This relationship may contribute to the physiological and psychological changes that occur during and after menopause, and may have far-reaching implications for women's health.

  18. Docosahexaenoic Acid Status in Pregnancy Determines the Maternal Docosahexaenoic Acid Status 3-, 6- and 12 Months Postpartum. Results from a Longitudinal Observational Study

    PubMed Central

    Markhus, Maria Wik; Rasinger, Josef Daniel; Malde, Marian Kjellevold; Frøyland, Livar; Skotheim, Siv; Braarud, Hanne Cecilie; Stormark, Kjell Morten; Graff, Ingvild Eide

    2015-01-01

    Background Essential fatty acid status as well as docosahexaenoic acid (DHA, 22:6n-3) declines during pregnancy and lactation. As a result, the DHA status may not be optimal for child development and may increase the risk for maternal postpartum depression. The objective of this study was to assess changes in the maternal fatty acid status from pregnancy to 12 months postpartum, and to study the impact of seafood consumption on the individual fatty acid status. Methods Blood samples and seafood consumption habits (gestation week 28, and three-, six- and 12 months postpartum) were collected in a longitudinal observational study of pregnant and postpartum women (n = 118). Multilevel linear modeling was used to assess both changes over time in the fatty acid status of red blood cells (RBC), and in the seafood consumption. Results Six fatty acids varied the most (>80%) across the four time points analyzed, including the derivative of the essential α-linoleic acid (ALA, 18:3n-3), DHA; the essential linoleic acid (LA, 18:2 n-6); and the LA derivative, arachidonic acid (AA, 20:4n-6). Over all, a large variation in individuals’ DHA- and AA status was observed; however, over the 15-month study period only small inter-individual differences in the longitudinal trajectory of DHA- and AA abundance in the RBC were detected. The median intake of seafood was lower than recommended. Regardless, the total weekly frequency of seafood and eicosapentaenoic acid (EPA, 20:5n-3)/DHA-supplement intake predicted the maternal level of DHA (μg/g RBC). Conclusion The period of depletion of the maternal DHA status during pregnancy and lactation, seem to turn to repletion from about six months postpartum towards one year after childbirth, irrespective of RBC concentration of DHA during pregnancy. Seafood and EPA/DHA-supplement intake predicted the DHA levels over time. Trial Registration www.helseforskning.etikkom.no 2009/570/REC, project number: 083.09 PMID:26331947

  19. 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.

  20. Present status of Accelerator-Based BNCT

    PubMed Central

    Kreiner, Andres Juan; Bergueiro, Javier; Cartelli, Daniel; Baldo, Matias; Castell, Walter; Asoia, Javier Gomez; Padulo, Javier; Suárez Sandín, Juan Carlos; Igarzabal, Marcelo; Erhardt, Julian; Mercuri, Daniel; Valda, Alejandro A.; Minsky, Daniel M.; Debray, Mario E.; Somacal, Hector R.; Capoulat, María Eugenia; Herrera, María S.; del Grosso, Mariela F.; Gagetti, Leonardo; Anzorena, Manuel Suarez; Canepa, Nicolas; Real, Nicolas; Gun, Marcelo; Tacca, Hernán

    2016-01-01

    Aim This work aims at giving an updated report of the worldwide status of Accelerator-Based BNCT (AB-BNCT). Background There is a generalized perception that the availability of accelerators installed in hospitals, as neutron sources, may be crucial for the advancement of BNCT. Accordingly, in recent years a significant effort has started to develop such machines. Materials and methods A variety of possible charged-particle induced nuclear reactions and the characteristics of the resulting neutron spectra are discussed along with the worldwide activity in suitable accelerator development. Results Endothermic 7Li(p,n)7Be and 9Be(p,n)9B and exothermic 9Be(d,n)10B are compared. In addition to having much better thermo-mechanical properties than Li, Be as a target leads to stable products. This is a significant advantage for a hospital-based facility. 9Be(p,n)9B needs at least 4–5 MeV bombarding energy to have a sufficient yield, while 9Be(d,n)10B can be utilized at about 1.4 MeV, implying the smallest possible accelerator. This reaction operating with a thin target can produce a sufficiently soft spectrum to be viable for AB-BNCT. The machines considered are electrostatic single ended or tandem accelerators or radiofrequency quadrupoles plus drift tube Linacs. Conclusions 7Li(p,n)7Be provides one of the best solutions for the production of epithermal neutron beams for deep-seated tumors. However, a Li-based target poses significant technological challenges. Hence, Be has been considered as an alternative target, both in combination with (p,n) and (d,n) reactions. 9Be(d,n)10B at 1.4 MeV, with a thin target has been shown to be a realistic option for the treatment of deep-seated lesions. PMID:26933390

  1. 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…

  2. Status recognition of isolator based on SmartGuard

    NASA Astrophysics Data System (ADS)

    Wang, Wanguo; Wang, Binhai; Wang, Zhenli; Li, Li; Zhang, Jingjing; Li, Yibin

    2013-07-01

    This paper concerns the method for checking the status of isolators and is applied in the sequence control in smart substation based on SmartGuard--a mobile inspection robot for substations. It can recognize the status of an isolator through analyzing its feature. We could get the homography matrix by using the SIFT feature between the template image and new acquired image, then get the range of isolator, finally recognize the status of isolator by image processing. The experiment of results proved that the method could recognize isolator status effectively. The substation realizes one key sequence control system through this technology based SmartGuard.

  3. Fatty acid composition of umbilical arteries and veins: possible implications for the fetal EFA-status.

    PubMed

    Hornstra, G; van Houwelingen, A C; Simonis, M; Gerrard, J M

    1989-06-01

    Fatty acid compositions were determined of phospholipids, isolated from umbilical arteries and veins, obtained from Dutch neonates after vaginal delivery, terminating normal pregnancy. The fatty acid profiles of the cord vessels were characterized by the absence of eicosapentaenoic (timnodonic) acid, a low (2-3%) content of linoleic acid and reasonable amounts of arachidonic acid (10-15%) and docosahexaenoic (cervonic) acid (3-5%). Significant amounts of Mead acid (1-4%) and its direct elongation product (0.5-2%) were also observed. In each cord, the efferent blood vessels contained significantly more Mead acid and other fatty acids of the oleic acid (n-9) family and less fatty acids of the linoleic (n-6) and linolenic (n-3) families than the afferent blood vessel. This indicates that the essential fatty acid (EFA) status of 'downstream' neonatal tissue may be marginal. No signs of EFA-deficiency were observed in endothelial and smooth muscle cells in culture, or in blood vessels from adults. In all cords 22:5(n-6) was significantly higher in the artery compared to the vein, whereas for all other (n-6) fatty acids this difference was negative. Since the synthesis of 22:5(n-6) is known to be stimulated when the required amount of cervonic acid, 22:6(n-3), is too low, our observations also suggest that the cervonic acid status of the neonates investigated was not optimal. Further studies are in progress to relate these findings to maternal EFA status and complications of pregnancy.

  4. Stearidonic acid as a supplemental source of ω-3 polyunsaturated fatty acids to enhance status for improved human health.

    PubMed

    Walker, Celia G; Jebb, Susan A; Calder, Philip C

    2013-02-01

    There is substantial evidence to show that consumption and increased blood levels of the very long-chain (VLC) ω-3 polyunsaturated fatty acids (ω-3 PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with health benefits. The consumption of oily fish is an effective way of increasing EPA and DHA intake and status, but intake in most Western countries remains below the levels recommended for optimal health. The reasons for this include not liking the taste, a concern about sustainability of fish supplies, or potential chemical and heavy metal contamination. Alternative dietary sources of ω-3 fatty acids to enhance EPA and DHA status in the body would therefore be beneficial. There are many non-fish food sources of the essential plant-derived ω-3 fatty acid α-linolenic acid, but conversion from this to longer-chain EPA and especially to DHA is poor. Stearidonic acid (SDA) is an intermediate fatty acid in the biosynthetic pathway from α-linolenic acid to VLC ω-3 PUFAs and the conversion from SDA is more efficient than from α-linolenic acid. However, there are few food sources rich in SDA. Oil crops naturally rich in SDA or enriched through genetic modification may offer an alternative supplemental oil to boost the population status of VLC ω-3 PUFAs. This review discusses the currently available evidence that increased SDA consumption can increase red blood cell EPA content, although this is less than the effect of supplementation directly with EPA. There is now a need for trials specifically designed to assess whether an increased SDA consumption would translate into improved human health outcomes.

  5. Effects of acid rain on forest nutrient status. Final report

    SciTech Connect

    Johnson, D.W.; Cole, D.W.

    1985-04-01

    In five forest sites (three in eastern Tennessee and two in western Washington) the effect of natural carbonic acid production on soil leaching was equaled or exceeded by that of atmospheric acid inputs. In a nitrogen-fixing red alder site in Washington, however, internal leaching by nitrification and nitric acid formation far exceeded atmospheric H/sup +/ inputs at any site. All other sites retained NO/sub 3//sup -/, and soil SO/sub 4//sup 2 -/ adsorption reduced the effectiveness of atmospheric H/sub 2/SO/sub 4/ inputs on soil leaching in two of the Tennessee sites and in the Washington red alder site. Atmospheric sulfur inputs exceeded the forest sulfur requirement in all five sites. Decomposer invertebrates appeared to be affected negatively by unrealistically large applications of SO/sub 4//sup 2 -/, either as KHSO/sub 4/ or K/sub 2/SO/sub 4/. Forest floor buffering prevented large changes in pH with acid SO/sub 4//sup 2 -/ treatments. Results indicate that effects of acid deposition on decomposer invertebrates are unlikely except at input levels much higher than ambient.

  6. 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.

  7. 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.

  8. 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.

  9. 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)

  10. 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…

  11. 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…

  12. STATUS REPORT: EVIDENCE BASED ADVANCES IN ...

    EPA Pesticide Factsheets

    This report summarizes the status of specific inhalation dosimetry procedures for gases as outlined in U.S. EPA’s 1994 Methods for Derivation of Inhalation Reference Concentrations and Applications of Inhalation Dosimetry (U.S. EPA 1994) and reviews recent scientific advances in gas dosimetry related to these procedures. These procedures are used predominately for interspecies extrapolation, typically from laboratory animal inhalation exposures to humans. The specific procedures addressed in this report are those used for the tracheobronchial (TB) and pulmonary (PU) regions of the respiratory tract and the procedure used for the systemic or extrarespiratory (ER) region. In addition, this report presents, reviews and discusses information and data on inhalation dosimetry in children and the adequacy of the procedures in the RfC Methods with regard to children. For the purposes of this report the scientific literature was searched from 1985 (about 10 years prior to the issuance of RfC Methods) to April 30, 2011. The studies identified in this update addressing overall concepts and approaches for portal-of-entry gas dosimetry in the TB and PU regions of the airways support the principles and procedures in RfC Methods. In some cases these studies suggest and provide examples of further refinement within the existing dosimetry modeling framework of the RfC Methods through development and application of mass transfer coefficients as regional measures of gas up

  13. Impact of multiple micronutrient vs. iron - folic acid supplements on maternal anemia and micronutrient status in pregnancy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background. Multiple micronutrient (MMN) supplements could increase hemoglobin and improve micronutrient status of pregnant women more than iron ± folic acid supplements alone. Objective. To compare the effects of MMN vs. iron ± folic acid supplements on hemoglobin and micronutrient status of pregn...

  14. Aggressive dogs are characterized by low omega-3 polyunsaturated fatty acid status.

    PubMed

    Re, Simona; Zanoletti, Marco; Emanuele, Enzo

    2008-03-01

    Canine aggressive behaviour is one of the most common problems being reported by dog owners. However, the biochemical basis of this phenomenon remains unclear. In humans, alterations in omega-3 plasma polyunsatured fatty acids and elevated omega6/omega-3 ratio have been linked to behavioural alterations, including aggression. Thus far, however, the relationship between plasma polyunsatured fatty acid status and aggression has not been investigated in the dog. In the present study we sought to investigate whether polyunsatured fatty acid status could be altered in plasma of pathologically aggressive Canis familiaris. Eighteen adult male German Shepherd dogs, aged 4.9 +/- 0.9 years, showing no clinical signs but aggression, were investigated. Eighteen healthy male dogs, aged 4.8 +/- 0.7 years, with a negative history of behavioural and neurological disorders served as controls. Baseline fasting plasma polyunsatured fatty acid composition was determined by gas chromatography. Compared to normal dogs, aggressive dogs showed lower docosahexaenoic acid (22:6 n-3) concentrations and a higher omega6/omega-3 ratio. In addition, they showed reduced cholesterol and bilirubin concentrations compared to their normally behaving counterparts. Altogether, our results suggest that low omega-3 fatty acids may adversely impact behaviour in dogs, resulting in greater propensity to aggression. However, given the cross-sectional design of our study, we cannot claim any causal relationship between the presence of alterations in fatty acid status and canine aggressiveness. Whether omega-3 fatty acids supplementation may be useful to reduce aggressive behaviour in the dog deserves further investigation.

  15. 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

    2002-12-06

    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.

  16. 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.

  17. KRAS-mutation status dependent effect of zoledronic acid in human non-small cell cancer preclinical models

    PubMed Central

    Kenessey, István; Kói, Krisztina; Horváth, Orsolya; Cserepes, Mihály; Molnár, Dávid; Izsák, Vera; Dobos, Judit; Hegedűs, Balázs

    2016-01-01

    Background In non-small cell lung cancer (NSCLC) KRAS-mutant status is a negative prognostic and predictive factor. Nitrogen-containing bisphosphonates inhibit prenylation of small G-proteins (e.g. Ras, Rac, Rho) and thus may affect proliferation and migration. In our preclinical work, we investigated the effect of an aminobisphosphonate compound (zoledronic acid) on mutant and wild type KRAS-expressing human NSCLC cell lines. Results We confirmed that zoledronic acid was unable to inhibit the prenylation of mutant K-Ras unlike in the case of wild type K-Ras. In case of in vitro proliferation, the KRAS-mutant human NSCLC cell lines showed resistance to zoledronic acid wild-type KRAS-cells proved to be sensitive. Combinatory application of zoledronic acid enhanced the cytostatic effect of cisplatin. Zoledronic acid did not induce significant apoptosis. In xenograft model, zoledronic acid significantly reduced the weight of wild type KRAS-EGFR-expressing xenograft tumor by decreasing the proliferative capacity. Futhermore, zoledronic acid induced VEGF expression and improved in vivo tumor vascularization. Materials and methods Membrane association of K-Ras was examined by Western-blot. In vitro cell viability, apoptotic cell death and migration were measured in NSCLC lines with different molecular background. The in vivo effect of zoledronic acid was investigated in a SCID mouse subcutaneous xenograft model. Conclusions The in vitro and in vivo inhibitory effect of zoledronic acid was based on the blockade of cell cycle in wild type KRAS-expressing human NSCLC cells. The zoledronic acid induced vascularization supported in vivo cytostatic effect. Our preclinical investigation suggests that patients with wild type KRAS-expressing NSCLC could potentially benefit from aminobisphosphonate therapy. PMID:27780929

  18. Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications.

    PubMed

    Davis, Brenda C; Kris-Etherton, Penny M

    2003-09-01

    Although vegetarian diets are generally lower in total fat, saturated fat, and cholesterol than are nonvegetarian diets, they provide comparable levels of essential fatty acids. Vegetarian, especially vegan, diets are relatively low in alpha-linolenic acid (ALA) compared with linoleic acid (LA) and provide little, if any, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Clinical studies suggest that tissue levels of long-chain n-3 fatty acids are depressed in vegetarians, particularly in vegans. n-3 Fatty acids have numerous physiologic benefits, including potent cardioprotective effects. These effects have been demonstrated for ALA as well as EPA and DHA, although the response is generally less for ALA than for EPA and DHA. Conversion of ALA by the body to the more active longer-chain metabolites is inefficient: < 5-10% for EPA and 2-5% for DHA. Thus, total n-3 requirements may be higher for vegetarians than for nonvegetarians, as vegetarians must rely on conversion of ALA to EPA and DHA. Because of the beneficial effects of n-3 fatty acids, it is recommended that vegetarians make dietary changes to optimize n-3 fatty acid status.

  19. Acid and base degraded products of ketorolac.

    PubMed

    Salaris, Margherita; Nieddu, Maria; Rubattu, Nicola; Testa, Cecilia; Luongo, Elvira; Rimoli, Maria Grazia; Boatto, Gianpiero

    2010-06-05

    The stability of ketorolac tromethamine was investigated in acid (0.5M HCl) and alkaline conditions (0.5M NaOH), using the same procedure reported by Devarajan et al. [2]. The acid and base degradation products were identified by liquid chromatography-mass spectrometry (LC-MS).

  20. Lipid-based antifungal agents: current status.

    PubMed

    Arikan, S; Rex, J H

    2001-03-01

    Immunocompromised patients are well known to be predisposed to developing invasive fungal infections. These infections are usually difficult to diagnose and more importantly, the resulting mortality rate is high. The limited number of antifungal agents available and their high rate of toxicity are the major factors complicating the issue. However, the development of lipid-based formulations of existing antifungal agents has opened a new era in antifungal therapy. The best examples are the lipid-based amphotericin B preparations, amphotericin B lipid complex (ABLC; Abelcet), amphotericin B colloidal dispersion (ABCD; Amphotec or Amphocil), and liposomal amphotericin B (AmBisome). These formulations have shown that antifungal activity is maintained while toxicity is reduced. This progress is followed by the incorporation of nystatin into liposomes. Liposomal nystatin formulation is under development and studies of it have provided encouraging data. Finally, lipid-based formulations of hamycin, miconazole, and ketoconazole have been developed but remain experimental. Advances in technology of liposomes and other lipid formulations have provided promising new tools for management of fungal infections.

  1. Solid Acid Based Fuel Cells

    DTIC Science & Technology

    2007-11-02

    superprotonic solid acids with elements such as P, As, Si and Ge, which have greater affinities to oxygen , we anticipate that the reduction reaction will be...bulk material consisted of an apatite phase (hexagonal symmetry) of variable composition, LixLa10-x(SiO4)6O3-x, with excess lithium residing in the...in Tables 1 and 2, indicate that this compound is a rather conventional apatite with fixed stoichiometry, LiLa9(SiO4)6O2 (x = 1). Such a result is

  2. Effects of polymannuronate on performance, antioxidant capacity, immune status, cecal microflora, and volatile fatty acids in broiler chickens.

    PubMed

    Zhu, Wenhui; Li, Defa; Wang, Jianhong; Wu, Hui; Xia, Xuan; Bi, Wanghua; Guan, Huashi; Zhang, Liying

    2015-03-01

    The aim of this study was to assess the effects of purified polymannuronate (PM) obtained from marine brown algae on the performance, antioxidant capacity, immune status, and cecal fermentation profile of broiler chickens. In a 42 d experiment, 540 (average BW 43.77±1.29 g) 1-d-old Arbor Acres male broilers were randomly divided into 5 treatments with 6 replicates of 18 chicks and fed a corn and soybean meal (SBM)-based diet supplemented with 0, 1, 2, 3, or 4 g/kg polymannuronate. Adding polymannuronate to the broiler chickens' diets resulted in a significantly increased ADG and improved feed conversion compared with the control treatment. From d 1 to 42, the ADG of broilers fed 1, 2, 3, or 4 g/kg of polymannuronate was increased by 2.58, 4.33, 4.20, and 3.47%, respectively. Furthermore, parameters related to immune status, antioxidant capacity, and composition of the cecal microflora in broiler chickens fed the polymannuronate-containing diets were altered compared with broiler chickens fed a diet without polymannuronate. Supplementation with polymannuronate significantly increased the concentrations of lactic acid and acetic acid in the cecum compared with the control group. The results indicate that polymannuronate has the potential to improve broiler chicken immune status, antioxidant capacity, and performance.

  3. Whole body acid-base modeling revisited.

    PubMed

    Ring, Troels; Nielsen, Søren

    2017-04-01

    The textbook account of whole body acid-base balance in terms of endogenous acid production, renal net acid excretion, and gastrointestinal alkali absorption, which is the only comprehensive model around, has never been applied in clinical practice or been formally validated. To improve understanding of acid-base modeling, we managed to write up this conventional model as an expression solely on urine chemistry. Renal net acid excretion and endogenous acid production were already formulated in terms of urine chemistry, and we could from the literature also see gastrointestinal alkali absorption in terms of urine excretions. With a few assumptions it was possible to see that this expression of net acid balance was arithmetically identical to minus urine charge, whereby under the development of acidosis, urine was predicted to acquire a net negative charge. The literature already mentions unexplained negative urine charges so we scrutinized a series of seminal papers and confirmed empirically the theoretical prediction that observed urine charge did acquire negative charge as acidosis developed. Hence, we can conclude that the conventional model is problematic since it predicts what is physiologically impossible. Therefore, we need a new model for whole body acid-base balance, which does not have impossible implications. Furthermore, new experimental studies are needed to account for charge imbalance in urine under development of acidosis.

  4. Synthesis of new kojic acid based unnatural α-amino acid derivatives.

    PubMed

    Balakrishna, C; Payili, Nagaraju; Yennam, Satyanarayana; Devi, P Uma; Behera, Manoranjan

    2015-11-01

    An efficient method for the preparation of kojic acid based α-amino acid derivatives by alkylation of glycinate schiff base with bromokojic acids have been described. Using this method, mono as well as di alkylated kojic acid-amino acid conjugates have been prepared. This is the first synthesis of C-linked kojic acid-amino acid conjugate where kojic acid is directly linked to amino acid through a C-C bond.

  5. 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

  6. 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…

  7. Status of the Home-Based Effort Within Head Start.

    ERIC Educational Resources Information Center

    Children First, Inc., Washington, DC.

    This status report is an attempt to provide a comprehensive picture of Head Start home-based programs which aimed at helping parents provide children with the same kinds of activities and support in their own homes that children would receive in any quality child development center. Data was collected through: (1) Children (1st) First, Inc.'s…

  8. 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.

  9. Phenolic Acids (Gallic and Tannic Acids) Modulate Antioxidant Status and Cisplatin Induced Nephrotoxicity in Rats.

    PubMed

    Akomolafe, Seun F; Akinyemi, Ayodele J; Anadozie, Scholarstical O

    2014-01-01

    Cisplatin (cis-diamminedichloroplatinum (II) or CDDP), used in the treatment of many solid-tissue cancers, has its chief side-effect in nephrotoxicity. Hence, this study sought to investigate and compare the protective effect of gallic acid (GA) and tannic acid (TA) against cisplatin induced nephrotoxicity in rats. The rats were given a prophylactic treatment of GA and TA orally at a dose of 20 and 40 mg/kg body weight for 7 consecutive days before the administration of a single intraperitoneal (i.p.) injection of cisplatin (CP) at 7.5 mg/kg bwt. The protective effects of both GA and TA on CP induced nephrotoxicity were investigated by assaying renal function, oxidative stress biomarkers, and histopathological examination of kidney architecture. A single dose of cisplatin (7.5 mg/kg bwt) injected i.p. caused a significant increase in some biomarkers of renal function (creatinine, uric acid, and urea levels), with a marked elevation in malondialdehyde (MDA) content accompanied by a significant (P < 0.05) decrease in reduced glutathione (GSH) content (103.27%) of kidney tissue as compared to control group. Furthermore, a significant (P < 0.05) reduction in kidney antioxidant enzymes (SOD, catalase, GPx, and GST) activity was observed. However, pretreatment with oral administration of tannic acid and gallic acid at a dose of 20 and 40 mg/kg body weight, respectively, for 7 days prior to cisplatin administration reduced histological renal damage and suppressed the generation of ROS, lipid peroxidation, and oxidative stress in kidney tissues. These results indicate that both gallic and tannic acids could serve as a preventive strategy against cisplatin induced nephrotoxicity.

  10. Circulating Unsaturated Fatty Acids Delineate the Metabolic Status of Obese Individuals

    PubMed Central

    Ni, Yan; Zhao, Linjing; Yu, Haoyong; Ma, Xiaojing; Bao, Yuqian; Rajani, Cynthia; Loo, Lenora W.M.; Shvetsov, Yurii B.; Yu, Herbert; Chen, Tianlu; Zhang, Yinan; Wang, Congrong; Hu, Cheng; Su, Mingming; Xie, Guoxiang; Zhao, Aihua; Jia, Wei; Jia, Weiping

    2015-01-01

    Background Obesity is not a homogeneous condition across individuals since about 25–40% of obese individuals can maintain healthy status with no apparent signs of metabolic complications. The simple anthropometric measure of body mass index does not always reflect the biological effects of excessive body fat on health, thus additional molecular characterizations of obese phenotypes are needed to assess the risk of developing subsequent metabolic conditions at an individual level. Methods To better understand the associations of free fatty acids (FFAs) with metabolic phenotypes of obesity, we applied a targeted metabolomics approach to measure 40 serum FFAs from 452 individuals who participated in four independent studies, using an ultra-performance liquid chromatograph coupled to a Xevo G2 quadruple time-of-flight mass spectrometer. Findings FFA levels were significantly elevated in overweight/obese subjects with diabetes compared to their healthy counterparts. We identified a group of unsaturated fatty acids (UFAs) that are closely correlated with metabolic status in two groups of obese individuals who underwent weight loss intervention and can predict the recurrence of diabetes at two years after metabolic surgery. Two UFAs, dihomo-gamma-linolenic acid and palmitoleic acid, were also able to predict the future development of metabolic syndrome (MS) in a group of obese subjects. Interpretation These findings underscore the potential role of UFAs in the MS pathogenesis and also as important markers in predicting the risk of developing diabetes in obese individuals or diabetes remission after a metabolic surgery. PMID:26629547

  11. Folate status of young Canadian women after folic acid fortification of grain products.

    PubMed

    Shuaibi, Aysheh M; House, James D; Sevenhuysen, Gustaaf P

    2008-12-01

    Women of childbearing age are advised to consume folic acid-containing supplements. Whether this remains necessary after folic acid fortification of the food supply in North America has yet to be determined. The objectives of this study were to assess folate intakes and the contribution of folic acid to the diets of women of childbearing age in the post-folic acid fortification era. Using a cross-sectional study design, fasting blood samples were obtained from 95 women (aged 18 to 25 years), and the samples were analyzed for serum and red blood cell folate, as well for total homocysteine. Dietary and supplemental folate intakes were assessed. The biochemical evidence showed that no women were folate deficient, but only 14% reached red blood cell folate concentrations associated with significant reductions in neural tube defect risk. Mean dietary intake of food folic acid was 96+/-64 microg/day, supplemental folic acid was 94+/-189 microg/day, natural folate was 314+/-134 microg/day, and the total intake, as dietary folate equivalents, was 646+/-368 microg dietary folate equivalents/day. Therefore, intakes of folic acid from fortified foods are within the level originally predicted for the fortification efforts; however, only 17% of participants met the special recommendation for women capable of becoming pregnant (400 microg folic acid daily from supplements, fortified foods, or both in addition to consuming food folate from a varied diet). These data suggest that women of childbearing age are achieving positive folate status in the postfortification era, but it may not be sufficient to achieve red blood cell folate concentrations associated with a significant reduction in neural tube defect risk. Even with food fortification, women of childbearing age should be advised to take a folic acid-containing supplement on a daily basis.

  12. Dietary docosahexaenoic acid but not arachidonic acid influences central nervous system fatty acid status in baboon neonates.

    PubMed

    Hsieh, Andrea T; Brenna, J Thomas

    2009-01-01

    The influence of dietary docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) on infant central nervous system (CNS) composition has implications for neural development, including vision, cognition, and motor function. We consider here combined results of three published studies of DHA/AA-containing formulas and breastfeeding to evaluate the CNS tissue response of baboon neonates with varied concentration and duration of DHA/AA consumption [G.Y. Diau, A.T. Hsieh, E.A. Sarkadi-Nagy, V. Wijendran, P.W. Nathanielsz, J.T. Brenna, The influence of long chain polyunsaturate supplementation on docosahexaenoic acid and arachidonic acid in baboon neonate central nervous system, BMC Med. 3 (2005) 11; A.T. Hsieh, J.C. Anthony, D.A. Diersen-Schade, et al., The influence of moderate and high dietary long chain polyunsaturated fatty acids (LCPUFA) on baboon neonate tissue fatty acids, Pediatr. Res. 61 (2007) 537-45; E. Sarkadi-Nagy, V. Wijendran, G.Y. Diau, et al., The influence of prematurity and long chain polyunsaturate supplementation in 4-week adjusted age baboon neonate brain and related tissues, Pediatr. Res. 54 (2003) 244-252]. A total of 43 neonates born spontaneously at term, or preterm by Cesarean section, consumed diets with DHA-AA (%w/w) at several levels: none (0,0), moderate (0.3, 0.6), or high (>0.6, 0.67 or 1.2). CNS fatty acids were analyzed at 4 and 12 weeks postpartum for term baboons and 7.5 weeks for preterm neonates. CNS DHA was consistently greater by 5-30% in neonates consuming DHA and nearer 30% for cortex. In contrast, CNS AA was unaffected by dietary AA and decreased in all structures with age. Dietary DHA consistently supports greater CNS DHA and maintenance of cortex DHA concentration with feeding duration, while CNS AA is not related to dietary supply. These data on structure-specific LCPUFA accretion may provide insight into neural mechanisms responsible for suboptimal functional outcomes in infants consuming diets that do not

  13. 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…

  14. 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).

  15. Soluble adenylyl cyclase is an acid-base sensor in epithelial base-secreting cells.

    PubMed

    Roa, Jinae N; Tresguerres, Martin

    2016-08-01

    Blood acid-base regulation by specialized epithelia, such as gills and kidney, requires the ability to sense blood acid-base status. Here, we developed primary cultures of ray (Urolophus halleri) gill cells to study mechanisms for acid-base sensing without the interference of whole animal hormonal regulation. Ray gills have abundant base-secreting cells, identified by their noticeable expression of vacuolar-type H(+)-ATPase (VHA), and also express the evolutionarily conserved acid-base sensor soluble adenylyl cyclase (sAC). Exposure of cultured cells to extracellular alkalosis (pH 8.0, 40 mM HCO3 (-)) triggered VHA translocation to the cell membrane, similar to previous reports in live animals experiencing blood alkalosis. VHA translocation was dependent on sAC, as it was blocked by the sAC-specific inhibitor KH7. Ray gill base-secreting cells also express transmembrane adenylyl cyclases (tmACs); however, tmAC inhibition by 2',5'-dideoxyadenosine did not prevent alkalosis-dependent VHA translocation, and tmAC activation by forskolin reduced the abundance of VHA at the cell membrane. This study demonstrates that sAC is a necessary and sufficient sensor of extracellular alkalosis in ray gill base-secreting cells. In addition, this study indicates that different sources of cAMP differentially modulate cell biology.

  16. The development of android - based children's nutritional status monitoring system

    NASA Astrophysics Data System (ADS)

    Suryanto, Agus; Paramita, Octavianti; Pribadi, Feddy Setio

    2017-03-01

    The calculation of BMI (Body Mass Index) is one of the methods to calculate the nutritional status of a person. The BMI calculation has not yet widely understood and known by the public. In addition, people should know the importance of progress in the development of child nutrition each month. Therefore, an application to determine the nutritional status of children based on Android was developed in this study. This study restricted the calculation for children with the age of 0-60 months. The application can run on a smartphone or tablet PC with android operating system due to the rapid development of a smartphone or tablet PC with android operating system and many people own and use it. The aim of this study was to produce a android app to calculate of nutritional status of children. This study was Research and Development (R & D), with a design approach using experimental studies. The steps in this study included analyzing the formula of the Body Mass Index (BMI) and developing the initial application with the help of a computer that includes the design and manufacture of display using Eclipse software. This study resulted in android application that can be used to calculate the nutritional status of children with the age 0-60 months. The results of MES or the error calculation analysis using body mass index formula was 0. In addition, the results of MAPE percentage was 0%. It shows that there is no error in the calculation of the application based on the BMI formula. The smaller value of MSE and MAPE leads to higher level of accuracy.

  17. 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.

  18. Linear Titration Curves of Acids and Bases.

    PubMed

    Joseph, N R

    1959-05-29

    The Henderson-Hasselbalch equation, by a simple transformation, becomes pH - pK = pA - pB, where pA and pB are the negative logarithms of acid and base concentrations. Sigmoid titration curves then reduce to straight lines; titration curves of polyelectrolytes, to families of straight lines. The method is applied to the titration of the dipeptide glycyl aminotricarballylic acid, with four titrable groups. Results are expressed as Cartesian and d'Ocagne nomograms. The latter is of a general form applicable to polyelectrolytes of any degree of complexity.

  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. 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.

  1. A new classification of HLA-DRB1 alleles based on acid–base properties of the amino acids located at positions 13, 70 and 71: impact on ACPA status or structural progression, and meta-analysis on 1235 patients with rheumatoid from two cohorts (ESPOIR and EAC cohort)

    PubMed Central

    Ruyssen-Witrand, Adeline; van Steenbergen, Hanna W; van Heemst, Jurgen; Gourraud, Pierre-Antoine; Nigon, Delphine; Lukas, Cédric; Miceli-Richard, Corinne; Jamard, Bénédicte; Cambon-Thomsen, Anne; Cantagrel, Alain; Dieudé, Philippe; van der Helm-van Mil, Annette H M; Constantin, Arnaud

    2015-01-01

    Objective To group HLA-DRB1 alleles based on acid–base properties of amino acids at positions 13, 70 and 71 and analyse their association with the presence of anticitrullinated peptide antibodies (ACPA) and structural progression in 2 cohorts of early rheumatoid arthritis (RA). Methods Patients with RA (N=612) from ESPOIR cohort and from EAC cohort (n=624) were genotyped for HLA-DRB1 alleles. The alleles containing the RAA sequence at positions 72–74 were classified into 3 groups according to the amino acid at positions 13, 70 and 71: BB encoding basic amino acids at positions 13, 70 and 71; A encoding acidic amino acids at positions 70 and 71; and BN encoding either neutral amino acids at position 13 and basic amino acids at positions 70 and 71, or basic amino acid at position 13 and neutral amino acids at positions 70 and 71. The associations between the different alleles and (1) the ACPA presence, and (2) the structural progression were assessed by χ2 test; a meta-analysis was performed on the 2 cohorts using the Mantel-Haenszel method. Results After meta-analysis, BB alleles were significantly associated with ACPA presence (OR (95% CI) 4.08 (3.14 to 5.31)) and structural progression (OR (95% CI) 2.33 (1.76 to 3.09)). The alleles protected significantly against ACPA presence (OR (95% CI) 0.37 (0.28 to 0.50)) and structural progression (OR (95% CI) 0.34 (0.23 to 0.50)). This acid–base classification allowed to separate another group BN with an intermediate risk of ACPA production (OR (95% CI) 1.14 (0.91 to 1.44)) and structural progression (OR (95% CI) 1.01 (0.77 to 1.33)). Conclusions This new classification permitted to make a hierarchy of HLA-DRB1 alleles in terms of association with ACPA presence or structural progression in early RA. PMID:26629363

  2. Nutrient based estimation of acid-base balance in vegetarians and non-vegetarians.

    PubMed

    Deriemaeker, Peter; Aerenhouts, Dirk; Hebbelinck, Marcel; Clarys, Peter

    2010-03-01

    A first objective of the present study was to estimate the acid-base balance of the food intake in vegetarians and non-vegetarians. A second objective was to evaluate if additional input of specific food items on the existing potential renal acid load (PRAL) list was necessary for the comparison of the two dietary patterns. Thirty vegetarians between the age of 18 and 30 years were matched for sex, age and BMI with 30 non-vegetarians. Based on the 3-days food diaries the acid-base status of the food intake was estimated using the PRAL method. Mean PRAL values as estimated with the standard table yielded an alkaline load of -5.4 +/- 14.4 mEq/d in the vegetarians compared to an acid load of 10.3 +/- 14.4 mEq/d in the nonvegetarians (p<0.001). Mean PRAL values as estimated with the extended table yielded an alkaline load of -10.9 +/-19.7 mEq/d in the vegetarians compared to an acid load of 13.8 +/- 17.1 mEq/d for the non-vegetarians (p<0.001). The findings of this study indicate that vegetarian food intake produces more alkaline outcomes compared to non-vegetarian diets. The use of the standard PRAL table was sufficient for discrimination between the two diets.

  3. Fertility and acidity status of latossolos (oxisols) under pasture in the Brazilian Cerrado.

    PubMed

    Vendrame, Pedro R S; Brito, Osmar R; Guimarães, Maria F; Martins, Eder S; Becquer, Thierry

    2010-12-01

    The Cerrado region, with over 50 million hectares of cultivated pasture, provides 55% of Brazilian beef production. Previous investigations have shown that about 70-80% of this pasture is affected by some kind of degradation, leading to low productivity. However, until now, few surveys have been carried out on a regional scale. The aim of the present work is both to assess the fertility and acidity levels of Cerrado soils under pasture and compare the variability of the soils characteristics on a regional scale. Two soil depths were sampled in different places within the studied area: (1) a surface horizon (0.0-0.2 m) in order to evaluate its fertility and acidity status for pasture, and (2) a subsurface horizon (0.6-0.8 m), used for classification. Most of soils had levels of nutrients below the reference values for adequate pasture development. Whatever the texture, about 90% of soils had low or very low availability of phosphorus. Only 7 to 14% of soils had low pH, high exchangeable aluminum, and aluminum saturation above the critical acidity level. Except for nitrogen, no significant difference was found between Latossolos Vermelhos and Latossolos Vermelho-Amarelos.

  4. The current status of haemoglobin-based blood substitutes.

    PubMed

    Cohn, S M

    1997-10-01

    Haemoglobin-based red cell substitutes have recently passed a myriad of safety studies and are now undergoing efficacy evaluation. There are numerous potential benefits with use of these solutions: they are readily available and have a long shelf-life; do not require typing and cross-matching; are free of viral or bacterial contamination; lack the immunosuppressive effects of blood; and have a much lower viscosity than blood. One-third of the 10 million units of blood transfused in the United States each year is utilized in the emergency setting. Therefore, a safe, effective substitute for blood should have significant impact upon the way we resuscitate bleeding patients. In this article, the current status of the various haemoglobin-based red cell substitutes is reviewed.

  5. Investigating Students' Reasoning about Acid-Base Reactions

    ERIC Educational Resources Information Center

    Cooper, Melanie M.; Kouyoumdjian, Hovig; Underwood, Sonia M.

    2016-01-01

    Acid-base chemistry is central to a wide range of reactions. If students are able to understand how and why acid-base reactions occur, it should provide a basis for reasoning about a host of other reactions. Here, we report the development of a method to characterize student reasoning about acid-base reactions based on their description of…

  6. 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)

  7. 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)

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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…

  13. A clinical approach to acid-base conundrums.

    PubMed

    Garrubba, Carl; Truscott, Judy

    2016-04-01

    Acid-base disorders can provide essential clues to underlying patient conditions. This article provides a simple, practical approach to identifying simple acid-base disorders and their compensatory mechanisms. Using this stepwise approach, clinicians can quickly identify and appropriately treat acid-base disorders.

  14. 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.

  15. Oleic acid-based gemini surfactants with carboxylic acid headgroups.

    PubMed

    Sakai, Kenichi; Umemoto, Naoki; Matsuda, Wataru; Takamatsu, Yuichiro; Matsumoto, Mutsuyoshi; Sakai, Hideki; Abe, Masahiko

    2011-01-01

    Anionic gemini surfactants with carboxylic acid headgroups have been synthesized from oleic acid. The hydrocarbon chain is covalently bound to the terminal carbonyl group of oleic acid via an ester bond, and the carboxylic acid headgroups are introduced to the cis double bond of oleic acid via disuccinyl units. The surfactants exhibit pH-dependent protonation-deprotonation behavior in aqueous solutions. In alkaline solutions (pH 9 in the presence of 10 mmol dm(-3) NaCl as the background electrolyte), the surfactants can lower the surface tension as well as form molecular assemblies, even in the region of low surfactant concentrations. Under acidic (pH 3) or neutral (pH 6-7) conditions, the surfactants are intrinsically insoluble in aqueous media and form a monolayer at the air/water interface. In this study, we have investigated physicochemical properties such as the function of the hydrocarbon chain length by means of static surface tension, pyrene fluorescence, dynamic light scattering, surface pressure-area isotherms, and infrared external reflection measurements.

  16. 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.

  17. 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

  18. Polarity based fractionation of fulvic acids.

    PubMed

    Li, Aimin; Hu, Jundong; Li, Wenhui; Zhang, Wei; Wang, Xuejun

    2009-11-01

    Fulvic acids from the soil of Peking University (PF) and a Nordic river (NF) were separated into well defined sub-fractions using sequential elution techniques based on eluent polarity. The chemical properties of the fractions including: PF1 and NF1 (eluted by 0.01 M HCl), PF2 and NF2 (eluted by 0.01 M HCl+20% methanol), PF3 and NF3 (eluted by 0.01 M HCl+40% methanol), and PF4 and NF4 (eluted by 100% methanol), were characterized using UV-Visible spectroscopy, elemental analysis and (13)C NMR. The results showed that the UV absorptions of the elution peaks at 280 nm (A280) increased from PF2 to PF4 and NF2 to NF4. No elution peaks were observed for PF1 and NF1. The carbon contents increased from 43.34% to 51.90% and 43.06% to 53.26% while the oxygen contents decreased from 46.39% to 36.76% and 49.76% to 40.03% for PF1-PF4 and NF1-NF4, respectively. As a polarity indicator, the (O+N)/C ratio for PF1-PF4 and NF1-NF4 decreased from 0.88 to 0.62 and 0.89 to 0.58, respectively. The aromatic carbon content increased from PF1 to PF4 and NF1 to NF4, suggesting an increase of the hydrophobicity of these fractions. The polarity was positively related to the ratio of UV absorption at 250 nm and 365 nm (E2/E3), and negatively related to the aromaticity. A high positive relationship between the aromaticity and E2/E3 of fulvic acid fractions was also obtained. The use of an eluent with a decreasing polarity allowed to providing simpler fractions of soil and aquatic fulvic acids.

  19. 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.

  20. 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

  1. 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.

  2. Effect of Dietary n − 3 Polyunsaturated Fatty Acids on Oxidant/Antioxidant Status in Macrosomic Offspring of Diabetic Rats

    PubMed Central

    Guermouche, B.; Soulimane-Mokhtari, N. A.; Bouanane, S.; Merzouk, H.; Merzouk, S.; Narce, M.

    2014-01-01

    The aim of this work was to determine the effect of dietary n − 3 PUFA on oxidant/antioxidant status, in vitro very low and low density lipoprotein (VLDL-LDL), and VLDL-LDL-fatty acid composition in macrosomic pups of diabetic mothers. We hypothesized that n − 3 PUFA would improve oxidative stress in macrosomia. Diabetes was induced in female Wistar rats fed with the ISIO diet (control) or with the EPAX diet (enriched in n − 3 PUFAs), by streptozotocin. The macrosomic pups were killed at birth (day 0) and at adulthood (day 90). Lipid parameters and VLDL-LDL-fatty acid composition were investigated. The oxidant/antioxidant status was determined by measuring plasma oxygen radical absorbance capacity (ORAC), hydroperoxides, carbonyl proteins, and VLDL-LDL oxidation. Macrosomic rats of ISIO fed diabetic mothers showed an increase in plasma and VLDL-LDL-triglycerides and VLDL-LDL-cholesterol levels and altered VLDL-LDL-fatty acid composition. Plasma ORAC was low with high hydroperoxide and carbonyl protein levels. The in vitro oxidizability of VLDL-LDL was enhanced in these macrosomic rats. The EPAX diet corrected lipid parameters and improved oxidant/antioxidant status but increased VLDL-LDL susceptibility to oxidation. Macrosomia is associated with lipid abnormalities and oxidative stress. n − 3 PUFA exerts favorable effects on lipid metabolism and on the oxidant/antioxidant status of macrosomic rats. However, there are no evident effects on VLDL-LDL oxidation. PMID:24987679

  3. 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

  4. 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

  5. Consumption of Red Meat, but Not Cooking Oils High in Polyunsaturated Fat, Is Associated with Higher Arachidonic Acid Status in Singapore Chinese Adults.

    PubMed

    Seah, Jowy Yi Hoong; Gay, Gibson Ming Wei; Su, Jin; Tai, E-Shyong; Yuan, Jian-Min; Koh, Woon-Puay; Ong, Choon Nam; van Dam, Rob M

    2017-01-31

    High arachidonic acid (AA; 20:4 n - 6) status may have adverse effects on inflammation and risk of cardiovascular diseases. Concerns about high intake of n - 6 polyunsaturated fatty acids (PUFAs) are based on the premise that endogenous conversion from linoleic acid (LA; 18:2 n - 6) is an important source of AA, but few population-based studies have investigated dietary determinants of AA status. In this study, we examined habitual food consumption in relation to plasma concentrations of AA and other PUFAs in population-based studies. We used cross-sectional data from 269 healthy, ethnic Chinese participants (25-80 years old) with contrasting intakes of fish and red meat from the Singapore Prospective Study Program and 769 healthy participants (44-74 years old) from the Singapore Chinese Health Study as a validation set. Multivariable linear regression was used to examine PUFA intake (% energy) and food sources of PUFA (fish, red meat, poultry, soy and cooking oils) in relation to plasma PUFAs (AA, LA, dihomo-gamma-linolenic acid (DGLA; 20:3 n - 6), alpha-linolenic acid (ALA; 18:3 n - 3), eicosapentaenoic acid (EPA; 20:5 n - 3), and docosahexaenoic acid (DHA; 22:6 n - 3)) concentrations. Higher intake of red meat was associated with higher plasma AA concentrations. High intake of PUFA or PUFA-rich oils was associated with higher plasma ALA but not with plasma AA. Higher intakes of soy were associated with higher ALA and fish with higher DHA and EPA concentrations. These associations were statistically significant (p < 0.05) in both studies. Red meat consumption, but not PUFA or PUFA-rich cooking oil, was associated with circulating AA suggesting that intake of pre-formed AA rather than LA is an important determinant of AA status. A diet high in fish, soy products and polyunsaturated cooking oil, and low in red meat may be associated with an optimal plasma profile of PUFA in this Chinese population.

  6. Consumption of Red Meat, but Not Cooking Oils High in Polyunsaturated Fat, Is Associated with Higher Arachidonic Acid Status in Singapore Chinese Adults

    PubMed Central

    Seah, Jowy Yi Hoong; Gay, Gibson Ming Wei; Su, Jin; Tai, E-Shyong; Yuan, Jian-Min; Koh, Woon-Puay; Ong, Choon Nam; van Dam, Rob M.

    2017-01-01

    High arachidonic acid (AA; 20:4n-6) status may have adverse effects on inflammation and risk of cardiovascular diseases. Concerns about high intake of n-6 polyunsaturated fatty acids (PUFAs) are based on the premise that endogenous conversion from linoleic acid (LA; 18:2n-6) is an important source of AA, but few population-based studies have investigated dietary determinants of AA status. In this study, we examined habitual food consumption in relation to plasma concentrations of AA and other PUFAs in population-based studies. We used cross-sectional data from 269 healthy, ethnic Chinese participants (25–80 years old) with contrasting intakes of fish and red meat from the Singapore Prospective Study Program and 769 healthy participants (44–74 years old) from the Singapore Chinese Health Study as a validation set. Multivariable linear regression was used to examine PUFA intake (% energy) and food sources of PUFA (fish, red meat, poultry, soy and cooking oils) in relation to plasma PUFAs (AA, LA, dihomo-gamma-linolenic acid (DGLA; 20:3n-6), alpha-linolenic acid (ALA; 18:3n-3), eicosapentaenoic acid (EPA; 20:5n-3), and docosahexaenoic acid (DHA; 22:6n-3)) concentrations. Higher intake of red meat was associated with higher plasma AA concentrations. High intake of PUFA or PUFA-rich oils was associated with higher plasma ALA but not with plasma AA. Higher intakes of soy were associated with higher ALA and fish with higher DHA and EPA concentrations. These associations were statistically significant (p < 0.05) in both studies. Red meat consumption, but not PUFA or PUFA-rich cooking oil, was associated with circulating AA suggesting that intake of pre-formed AA rather than LA is an important determinant of AA status. A diet high in fish, soy products and polyunsaturated cooking oil, and low in red meat may be associated with an optimal plasma profile of PUFA in this Chinese population. PMID:28146136

  7. High oleic ready-to-use therapeutic food maintains docosahexaenoic acid status in severe malnutrition: a randomized, blinded trial

    PubMed Central

    Hsieh, Ji-Cheng; Liu, Lei; Zeilani, Mamane; Ickes, Scott; Trehan, Indi; Maleta, Ken; Craig, Christina; Thakwalakwa, Chrissie; Singh, Lauren; Brenna, J. Thomas; Manary, Mark J.

    2015-01-01

    Objective Ready-to-use therapeutic food (RUTF) is the preferred treatment for uncomplicated severe acute malnutrition. RUTF contains large amounts of linoleic acid and very little α-linolenic acid, which may reduce the availability of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) to the recovering child. A novel high oleic RUTF (HO-RUTF) was developed with less linoleic acid to determine its effect on DHA and EPA status. Methods We conducted a prospective, randomized, double-blinded, clinical effectiveness trial treating rural Malawian children with severe acute malnutrition. Children were treated with either HO-RUTF or standard RUTF. Plasma phospholipid (PL) fatty acid status was measured upon enrollment and after 4 weeks and compared between the two intervention groups. Results Among the 141 children enrolled, 48/71 receiving HO-RUTF and 50/70 receiving RUTF recovered. Plasma PL samples were analyzed from 43 children consuming HO-RUTF and 35 children consuming RUTF. The change in DHA content during the first 4 weeks was +4% and −25% in the HO-RUTF and RUTF groups, respectively (P = 0.04). For EPA, the change in content was 63% and −24% in the HO-RUTF and RUTF groups (P < 0.001). For arachidonic acid, the change in content was −3% and 13% in the HO-RUTF and RUTF groups (P < 0.009). Conclusions The changes in DHA and EPA seen in the children treated with HO-RUTF warrant further investigation as they suggest HO-RUTF support improved PUFA status, necessary for neural development and recovery. PMID:25633498

  8. 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.

  9. Acid-base bifunctional catalytic surfaces for nucleophilic addition reactions.

    PubMed

    Motokura, Ken; Tada, Mizuki; Iwasawa, Yasuhiro

    2008-09-01

    This article illustrates the modification of oxide surfaces with organic amine functional groups to create acid-base bifunctional catalysts, summarizing our previous reports and also presenting new data. Immobilization of organic amines as bases on inorganic solid-acid surfaces afforded highly active acid-base bifunctional catalysts, which enabled various organic transformations including C--C coupling reactions, though these reactions did not proceed with either the homogeneous amine precursors or the acidic supports alone. Spectroscopic characterization, such as by solid-state MAS NMR and FTIR, revealed not only the interactions between acidic and basic sites but also bifunctional catalytic reaction mechanisms.

  10. Suicide Deaths of Active-Duty U.S. Military and Omega-3 Fatty-Acid Status: A Case-Control Comparison

    DTIC Science & Technology

    2011-01-01

    Deaths e1J Clin Psychiatry Suicide Deaths of Active-Duty US Military and Omega -3 Fatty - Acid Status: A Case-Control Comparison Michael D. Lewis, MD...factors. Objective: To determine whether deficiencies of neuroactive, highly unsaturated omega -3 essential fatty acids (n-3 HUFAs), in particular...U.S. Military And Omega -3 Fatty - Acid Status: A Case-Control Comparison 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

  11. Thermochemical comparisons of homogeneous and heterogeneous acids and bases. 1. Sulfonic acid solutions and resins as prototype Broensted acids

    SciTech Connect

    Arnett, E.M.; Haaksma, R.A.; Chawla, B.; Healy, M.H.

    1986-08-06

    Heats of ionization by thermometric titration for a series of bases (or acids) can be used to compare solid acids (or bases) with liquid analogues bearing the same functionalities in homogeneous solutions. The method is demonstrated for Broensted acids by reacting a series of substituted nitrogen bases with solutions of p-toluenesulfonic acid (PTSA) in acetonitrile and with suspensions of the microporous polymeric arylsulfonic acid resin-Dowex 50W-X8 in the same solvent. Under well-controlled anhydrous conditions there is a good correlation (r = 0.992) between the heats of reaction of the bases with the homogeneous and heterogeneous acid systems, but the homogeneous system gives a more exothermic interaction by 3-4 kcal mol/sup -1/ for a series of 29 substituted pyrimidines, anilines, and some other amines. This difference may be attributed to homohydrogen bonding interactions between excess acid and sulfonate anion sites which are more restricted geometrically in the resin than in solution. Other factors which affect the enthalpy change for the acid-base interaction are the acid/base ratio, the water content of the sulfonic acid, the solvent, and the resin structure (e.g., microporous vs. macroporous). Steric hindrance in the base does not differentiate solid from homogeneous acid. In addition to the use of titration calorimetry, heats of immersion are reported for the Dowex-arylsulfonic acid resins and the Nafion-perfluorinated sulfonic acid resin in a series of basic liquids. The results are compared with each other and with those from a previous study of several varieties of coal.

  12. 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.

  13. The effect of conjugated linoleic acid supplementation on the nutritional status of COPD patients

    PubMed Central

    Ghobadi, Hassan; Matin, Somaieh; Nemati, Ali; Naghizadeh-baghi, Abbas

    2016-01-01

    Background COPD patients are susceptible to anorexia, reduction of caloric intake, weight loss, and malnutrition. One of the possible mechanisms is the increase of inflammatory markers such as interleukin 1β (IL1β), is highly correlated with anorexia. Considering the anti-inflammatory role of conjugated linoleic acid (CLA), this study aimed to investigate the effect of CLA supplementation on the nutritional status of COPD patients. Patients and methods In a double-blind clinical trial, 93 COPD patients who volunteered to participate in the study and who filled out a written consent form, were randomly assigned to control or supplementation groups. The patients in the supplementation group received 3.2 g of CLA on a daily basis for 6 weeks, while those in the control group received placebo on a daily basis for 6 weeks. For IL1β assessment, the patients’ anthropometric indices and appetite score were checked and their blood samples were collected both before and after the treatment. Moreover, in order to investigate the changes in the caloric intake trend during the study, their dietary intake levels were assessed using 24-hour dietary recall, 3 days a week at the onset, in the 4th week, and at the end of the study. Eventually, 90 patients completed the study. Results The results demonstrated a significant increase in appetite score (P=0.001), average caloric intake (P=0.01), and macronutrient intake (P<0.05), while a significant decrease was observed in the serum level of IL1β among the patients of the supplementation group (P=0.008). Meanwhile, although the supplementation group’s body mass index was also higher on completion, compared to their own initial state as well as to that in the control group, the differences were not significant (P=0.13). Conclusion The findings of this research indicate that the consumption of CLA supplementation can be effective in regulating the appetite and improving the nutritional status of patients suffering from COPD

  14. Short course acid suppressive treatment for patients with functional dyspepsia: results depend on Helicobacter pylori status

    PubMed Central

    Blum, A; Arnold, R; Stolte, M; Fischer, M; Koelz, H; the, F

    2000-01-01

    BACKGROUND AND AIMS—Treatment of functional dyspepsia with acid inhibitors is controversial and it is not known if the presence of Helicobacter pylori infection influences the response.
METHODS—After a complete diagnostic workup, 792 patients with functional dyspepsia unresponsive to one week of low dose antacid treatment were randomised to two weeks of treatment with placebo, ranitidine 150 mg, omeprazole 10 mg, or omeprazole 20 mg daily. Individual dyspeptic and other abdominal symptoms were evaluated before and after treatment according to H pylori status.
RESULTS—The proportions of patients considered to be in remission (intention to treat) at the end of treatment with placebo, ranitidine 150 mg, omeprazole 10 mg, and omeprazole 20 mg were, respectively, 42%, 50%, 48%, and 59% in the H pylori positive group and 66%, 73%, 64%, and 71% in the H pylori negative group. In H pylori positive patients, the therapeutic gain over placebo was significant for omeprazole 20 mg (17.6%, 95% confidence intervals (CI) 4.2-31.0; p<0.014 using the Bonferroni-adjusted p level of 0.017) but not for omeprazole 10 mg (6.8%, 95% CI −6.7-20.4) or ranitidine 150 mg (8.9%, 95% CI −4.2-21.9). There was no significant therapeutic gain from active treatment over placebo in H pylori negative patients. Complete disappearance of symptoms and improvement in quality of life also occurred most frequently with omeprazole 20 mg and was significant in both H pylori positive and H pylori negative groups. The six month relapse rate of symptoms requiring treatment was low (<20%) in all groups.
CONCLUSIONS—Omeprazole 20 mg per day had a small but significant favourable effect on outcome in H pylori positive patients. The differential response in these patients may be explained by an enhanced antisecretory response in the presence of H pylori. The effect of weaker acid inhibition was unsatisfactory.


Keywords: functional dyspepsia; omeprazole; ranitidine

  15. Kainic acid dose affects delayed cell death mechanism after status epilepticus.

    PubMed

    Tokuhara, Daisuke; Sakuma, Satoru; Hattori, Hideji; Matsuoka, Osamu; Yamano, Tsunekazu

    2007-01-01

    Kainic acid (KA)-induced status epilepticus (SE) produces hippocampal neuronal death, which varies from necrosis to apoptosis or programmed cell death (PCD). We examined whether the type of neuronal death was dependent on KA dose. Adult rats were induced SE by intraperitoneal injection of KA at 9 mg/kg (K9) or 12 mg/kg (K12). Hippocampal neuronal death was assessed by TUNEL staining, electron microscopy, and Western blotting of caspase-3 on days 1, 3 and 7 after SE induction. K12 rats showed higher a mortality rate and shorter latency to the onset of SE when compared with K9 rats. In both groups, acidophilic and pyknotic neurons were evident in CA1 at 24h after SE and neuronal loss developed from day 3. The degenerated neurons became TUNEL-positive on days 3 and 7 in K9 rats but not in K12 rats. Caspase-3 activation was detected on days 3 and 7 in K9 rats but was undetectable in K12 rats. Ultrastructural study revealed shrunken neurons exhibiting pyknotic nuclei containing small and dispersed chromatin clumps 24h after SE in CA1. No cells exhibited apoptosis. On days 3 and 7, the degenerated neurons were necrotic with high electron density and small chromatin clumps. There were no ultrastructural differences between the K9 and K12 groups. These results revealed that differences in KA dose affected the delayed cell death (3 and 7 days after SE); however, no effect was seen on the early cell death (24h after SE). Moderate-dose KA induced necrosis, while low-dose KA induced PCD.

  16. Involvement of Abscisic Acid in Regulating Water Status in Phaseolus vulgaris L. during Chilling 1

    PubMed Central

    Pardossi, Alberto; Vernieri, Paolo; Tognoni, Franco

    1992-01-01

    During the first hours of chilling, bean (Phaseolus vulgaris L., cv Mondragone) seedlings suffer severe water stress and wilt without any significant increase in leaf abscisic acid (ABA) content (P. Vernieri, A. Pardossi, F. Tognoni [1991] Aust J Plant Physiol 18: 25-35). Plants regain turgor after 30 to 40 h. We hypothesized that inability to rapidly synthesize ABA at low temperatures contributes to chilling-induced water stress and that turgor recovery after 30 to 40 h is mediated by changes in endogenous ABA content. Entire bean seedlings were subjected to long-term (up to 6 d) chilling (3°C, 0.2-0.4 kPa vapor pressure deficit, 100 μmol·m−2·s−1 photosynthetic photon flux density, continuous fluorescent light). During the first 24 h, stomata remained open, and plants rapidly wilted as leaf transpiration exceeded root water absorption. During this phase, ABA did not accumulate in leaves or in roots. After 24 h, ABA content increased in both tissues, leaf diffusion resistance increased, and plants rehydrated and regained turgor. No osmotic adjustment was associated with turgor recovery. Following turgor recovery, stomata remained closed, and ABA levels in both roots and leaves were elevated compared with controls. The application of ABA (0.1 mm) to the root system of the plants throughout exposure to 3°C prevented the chilling-induced water stress. Excised leaves fed 0.1 mm ABA via the transpiration stream had greater leaf diffusion resistance at 20 and 3°C compared with non-ABA fed controls, but the amount of ABA needed to elicit a given degree of stomatal closure was higher at 3°C compared with 20°C. These findings suggest that endogenous ABA may play a role in ameliorating plant water status during chilling. PMID:16653112

  17. Administration of Simvastatin after Kainic Acid-Induced Status Epilepticus Restrains Chronic Temporal Lobe Epilepsy

    PubMed Central

    Qiao, Weidong; Lu, Dunyue; Wei, Lanlan; Na, Meng; Song, Yuanyuan; Hou, Xiaohua; Lin, Zhiguo

    2011-01-01

    In this study, we examined the effect of chronic administration of simvastatin immediately after status epilepticus (SE) on rat brain with temporal lobe epilepsy (TLE). First, we evaluated cytokines expression at 3 days post KA-lesion in hippocampus and found that simvastatin-treatment suppressed lesion-induced expression of interleukin (IL)-1β and tumor necrosis factor-α (TNF-α). Further, we quantified reactive astrocytosis using glial fibrillary acidic protein (GFAP) staining and neuron loss using Nissl staining in hippocampus at 4–6 months after KA-lesion. We found that simvastatin suppressed reactive astrocytosis demonstrated by a significant decrease in GFAP-positive cells, and attenuated loss of pyramidal neurons in CA3 and interneurons in dentate hilar (DH). We next assessed aberrant mossy fiber sprouting (MFS) that is known to contribute to recurrence of spontaneous seizure in epileptic brain. In contrast to the robust MFS observed in saline-treated animals, the extent of MFS was restrained by simvastatin in epileptic rats. Attenuated MFS was related to decreased neuronal loss in CA3 and DH, which is possibly a mechanism underlying decreased hippocampal susceptibility in animal treated with simvastatin. Electronic encephalography (EEG) was recorded during 4 to 6 months after KA-lesion. The frequency of abnormal spikes in rats with simvastatin-treatment decreased significantly compared to the saline group. In summary, simvastatin treatment suppressed cytokines expression and reactive astrocytosis and decreased the frequency of discharges of epileptic brain, which might be due to the inhibition of MFS in DH. Our study suggests that simvastatin administration might be a possible intervention and promising strategy for preventing SE exacerbating to chronic epilepsy. PMID:21949812

  18. Weak vs Strong Acids and Bases: The Football Analogy

    NASA Astrophysics Data System (ADS)

    Silverstein, Todd P.

    2000-07-01

    An important topic in any introductory chemistry course is that of acids and bases. Students generally have no trouble learning the Brønsted-Lowry definition of an acid as a proton donor and a base as a proton acceptor. Problems often arise, however, when chemistry teachers attempt to explain the difference between weak and strong acids, and between weak and strong bases. For acids in aqueous solution, discussing complete in contrast to partial ionization works well for those with a strong grasp of the equilibrium concept, but for many students it does not seem to do the trick. Partial ionization may not evoke much in the mind of a "visual learner". Accordingly, I have developed a football analogy for acids and bases in which acids are compared to quarterbacks, whose job is to get rid of the ball (H+). A strong acid, like an excellent quarterback, delivers the ball effectively; a weak acid, like a poor quarterback, is often left holding the ball. Furthermore, bases may be likened to wide receivers, whose job is to catch and hold onto the ball (H+). A strong base, like an excellent wide receiver, holds onto the ball; a weak base, like a poor receiver, often drops the ball. The concept of throwing and catching a ball is easy to visualize and the analogy to acids and bases can help even students unfamiliar with the mores of the gridiron to comprehend the mores of aqueous protons.

  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. 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. Determination of acidity constants of acid-base indicators by second-derivative spectrophotometry

    NASA Astrophysics Data System (ADS)

    Kara, Derya; Alkan, Mahir

    2000-12-01

    A method for calculation of acid-base dissociation constants of monoprotic weak organic acids whose acid and base species have overlapping spectra from absorptiometric and pH measurements is described. It has been shown that the second-derivative spectrophotometry can effectively be used for determining the dissociation constants, when dissociation constants obtained for methyl orange and bromothymol blue were compared with the values given in the literature.

  2. Chip-based sequencing nucleic acids

    DOEpatents

    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.

  3. 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.

  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. 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.

  6. 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.

  7. Calcium-based Lewis acid catalysts.

    PubMed

    Begouin, Jeanne-Marie; Niggemann, Meike

    2013-06-17

    Recently, Lewis acidic calcium salts bearing weakly coordinating anions such as Ca(NTf₂)₂, Ca(OTf)₂, CaF₂ and Ca[OCH(CF₃)₂]₂ have been discovered as catalysts for the transformation of alcohols, olefins and carbonyl compounds. High stability towards air and moisture, selectivity and high reactivity under mild reaction conditions render these catalysts a sustainable and mild alternative to transition metals, rare-earth metals or strong Brønsted acids.

  8. 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

  9. Fatty acid status in early life in low-income countries--overview of the situation, policy and research priorities.

    PubMed

    Briend, André; Dewey, Kathryn G; Reinhart, Gregory A

    2011-04-01

    Fat intake may be low in low-income countries and little information is available on its composition in terms of (n-3) and (n-6) fatty acids (FA). As a result, long chain poly-unsaturated fatty acid (LCPUFA) status is a concern, especially in settings where fish intake is low and/or common sources of fat have a low alpha-linolenic acid (ALA) and high linoleic acid (LA) content. High LA levels, as found for instance in sunflower, safflower, corn, peanut and soy oils, may inhibit the conversion of ALA into its LC-PUFA derivatives. Other factors that affect LA and ALA conversion into LC-PUFA, including genetic factors, are little known and should also be investigated in different populations. Different interventions that could feasibly improve LC-PUFA status in low-income countries should be tested and their effects on functional outcomes assessed, preferably starting from pregnancy. Identifying affordable sources of ALA or LC-PUFA that could be made locally available and easily introduced in the diet early in life is also a priority.

  10. 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…

  11. 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

  12. Acid-base properties of titanium-antimony oxides catalysts

    SciTech Connect

    Zenkovets, G.A.; Paukshtis, E.A.; Tarasova, D.V.; Yurchenko, E.N.

    1982-06-01

    The acid-base properties of titanium-antimony oxide catalysts were studied by the methods of back titration and ir spectroscopy. The interrelationship between the acid-base and catalytic properties in the oxidative ammonolysis of propylene was discussed. 3 figures, 1 table.

  13. 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.

  14. Luminol as a fluorescent acid-base indicator.

    PubMed

    Erdey, L; Buzás, I; Vigh, K

    1966-03-01

    The acid and base dissociation constants of luminol are determined at various ionic strengths. The transition interval occurs at pH 7.7-9.0, therefore luminol is a fluorescent indicator for the titration of strong and weak acids and strong bases. Its value as an indicator is established by titrating milk, red wine and cherry juice.

  15. Proton defect solvation and dynamics in aqueous acid and base.

    PubMed

    Kale, Seyit; Herzfeld, Judith

    2012-10-29

    Easy come, easy go: LEWIS, a new model of reactive and polarizable water that enables the simulation of a statistically reliable number of proton hopping events in aqueous acid and base at concentrations of practical interest, is used to evaluate proton transfer intermediates in aqueous acid and base (picture, left and right, respectively).

  16. Perioperative Acid-Base and Electrolyte Disturbances.

    PubMed

    Beer, Kari Santoro; Waddell, Lori S

    2015-09-01

    Obtaining and interpreting blood gas and electrolyte levels is essential in the management of perioperative veterinary patients. Metabolic and electrolyte alterations are common in critically ill surgical patients, and can lead to alterations in cardiovascular function, neurologic status, respiratory function, and even response to various drug therapies. Several common perioperative conditions are discussed in this article, including metabolic disturbances, electrolyte abnormalities (hyponatremia and hypernatremia, hyperkalemia), and respiratory abnormalities.

  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. Effects of vine water status on dimethyl sulfur potential, ammonium, and amino acid contents in Grenache Noir grapes (Vitis vinifera).

    PubMed

    De Royer Dupré, N; Schneider, R; Payan, J C; Salançon, E; Razungles, A

    2014-04-02

    We studied the effect of vine water status on the dimethyl sulfur potential (DMSP), ammonium, and amino acid contents of the berry during the maturation of Grenache Noir grapes. Water deficit increased the accumulation of amino acids in berries and favored yeast assimilable amino nitrogen. Similarly, ammonium content was higher in berries from vines subjected to moderate water deficit. DMSP content followed the same trend as yeast assimilable amino acid content, with higher concentrations observed in the berries of vines subjected to water deficit. The high DMSP and yeast assimilable nitrogen contents of musts from vines subjected to water deficit resulted in a better preservation of DMSP during winemaking. The wines produced from these musts had a higher DMSP level and would therefore probably have a higher aroma shelf life, because the DMSP determines the rate of release of dimethyl sulfur during wine storage, and this compound enhances fruity notes.

  19. 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)

  20. Ammonia Transporters and Their Role in Acid-Base Balance.

    PubMed

    Weiner, I David; Verlander, Jill W

    2017-04-01

    Acid-base homeostasis is critical to maintenance of normal health. Renal ammonia excretion is the quantitatively predominant component of renal net acid excretion, both under basal conditions and in response to acid-base disturbances. Although titratable acid excretion also contributes to renal net acid excretion, the quantitative contribution of titratable acid excretion is less than that of ammonia under basal conditions and is only a minor component of the adaptive response to acid-base disturbances. In contrast to other urinary solutes, ammonia is produced in the kidney and then is selectively transported either into the urine or the renal vein. The proportion of ammonia that the kidney produces that is excreted in the urine varies dramatically in response to physiological stimuli, and only urinary ammonia excretion contributes to acid-base homeostasis. As a result, selective and regulated renal ammonia transport by renal epithelial cells is central to acid-base homeostasis. Both molecular forms of ammonia, NH3 and NH4(+), are transported by specific proteins, and regulation of these transport processes determines the eventual fate of the ammonia produced. In this review, we discuss these issues, and then discuss in detail the specific proteins involved in renal epithelial cell ammonia transport.

  1. 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.

  2. Supplemented gamma-linolenic acid and eicosapentaenoic acid influence bone status in young male rats: effects on free urinary collagen crosslinks, total urinary hydroxyproline, and bone calcium content.

    PubMed

    Claassen, N; Potgieter, H C; Seppa, M; Vermaak, W J; Coetzer, H; Van Papendorp, D H; Kruger, M C

    1995-04-01

    The effect of different ratios of the prostaglandin precursors gamma-linolenic (GLA) and eicosapentaenoic (EPA) acids on bone status in growing rats measured as a function of free urinary pyridinium crosslinks and hydroxyproline levels was investigated. Male Sprague-Dawley rats were weaned onto an essential fatty acid deficient diet and from their fifth week, different groups of rats received a balanced, semisynthetic diet, supplemented with different ratios of GLA:EPA supplied as a mixture of evening primrose oil (EPO) and fish oil (FO). Controls were supplemented with linoleic (LA; sunflower oil) and alpha-linolenic (ALA; linseed oil) acids (3:1) or a commercially available rat chow. Animals were terminated at 84 days and femur length, ash weight, calcium content, free urinary pyridinium crosslinks (Pyd and Dpyd), total hydroxyproline (Hyp), and creatinine levels measured. Free urinary Pyd and Dpyd are good indicators of bone status and they correlated well with Hyp. Pyd and Dpyd excretion were significantly decreased in the higher GLA:EPA dietary groups and correlated well (r = 0.7) with Hyp levels. Concomitantly, bone calcium content increased significantly in the same dietary groups. These results suggest that diet supplementation with relatively high GLA:EPA ratios are more effective in inhibiting bone resorption than LA:ALA.

  3. 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.

  4. Nucleic Acid Duplexes Incorporating a Dissociable Covalent Base Pair

    NASA Astrophysics Data System (ADS)

    Gao, Kui; Orgel, Leslie E.

    1999-12-01

    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.

  5. 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.

  6. 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.

  7. 38 CFR 3.1713 - Eligibility based on status before 1958.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... AFFAIRS ADJUDICATION Burial Benefits Burial Benefits: Other § 3.1713 Eligibility based on status before... entitlement to burial benefits, burial benefits will be paid, if otherwise in order, even though such...

  8. 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

  9. Nucleic acid tool enzymes-aided signal amplification strategy for biochemical analysis: status and challenges.

    PubMed

    Qing, Taiping; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Xu, Fengzhou; Wen, Li; Shangguan, Jingfang; Mao, Zhengui; Lei, Yanli

    2016-04-01

    Owing to their highly efficient catalytic effects and substrate specificity, the nucleic acid tool enzymes are applied as 'nano-tools' for manipulating different nucleic acid substrates both in the test-tube and in living organisms. In addition to the function as molecular scissors and molecular glue in genetic engineering, the application of nucleic acid tool enzymes in biochemical analysis has also been extensively developed in the past few decades. Used as amplifying labels for biorecognition events, the nucleic acid tool enzymes are mainly applied in nucleic acids amplification sensing, as well as the amplification sensing of biorelated variations of nucleic acids. With the introduction of aptamers, which can bind different target molecules, the nucleic acid tool enzymes-aided signal amplification strategies can also be used to sense non-nucleic targets (e.g., ions, small molecules, proteins, and cells). This review describes and discusses the amplification strategies of nucleic acid tool enzymes-aided biosensors for biochemical analysis applications. Various analytes, including nucleic acids, ions, small molecules, proteins, and cells, are reviewed briefly. This work also addresses the future trends and outlooks for signal amplification in nucleic acid tool enzymes-aided biosensors.

  10. 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.

  11. Zygomycetes-based biorefinery: present status and future prospects.

    PubMed

    Ferreira, Jorge A; Lennartsson, Patrik R; Edebo, Lars; Taherzadeh, Mohammad J

    2013-05-01

    Fungi of the phylum Zygomycetes fulfil all requirements for being utilized as core catalysts in biorefineries, and would be useful in creating new sustainable products. Apart from the extended use of Zygomycetes in preparing fermented foods, industrial metabolites such as lactic acid, fumaric acid, and ethanol are produced from a vast array of feedstocks with the aid of Zygomycetes. These fungi produce enzymes that facilitate their assimilation of various complex substrates, e.g., starch, cellulose, phytic acid, and proteins, which is relevant from an industrial point of view. The enzymes produced are capable of catalyzing various reactions involved in biodiesel production, preparation of corticosteroid drugs, etc. Biomass produced with the aid of Zygomycetes consists of proteins with superior amino acid composition, but also lipids and chitosan. The biomass is presently being tested for animal feed purposes, such as fish feed, as well as for lipid extraction and chitosan production. Complete or partial employment of Zygomycetes in biorefining procedures is consequently attractive, and is expected to be implemented within a near future.

  12. 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.

  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. 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.

  15. L-ascorbic acid and α tocopherol supplementation and antioxidant status in nickel- or lead-exposed rat brain tissue.

    PubMed

    Das, Kusal K; Saha, Sikha

    2010-01-01

    We evaluated the effect of L-ascorbic acid and alpha-tocopherol supplementation on plasma and whole brain nitric oxide level and antioxidant status in nickel sulfate- or lead acetate- treated male albino rats. Nitric oxide and lipid peroxide levels in whole brain tissue and plasma increased following nickel and lead treatment but significantly returned to near-normal values upon L-ascorbic acid or alpha-tocopherol supplementation. In brain tissue, antioxidant enzymes--superoxide dismutase, glutathione peroxidase, glutathione peroxidase, and catalase--along with the glutathione level decreased significantly after both treatments but significantly improved upon simultaneous supplementation with L-ascorbic acid or alpha-tocopherol. Lead-treated animals showed a greater improvement with alpha-tocopherol, whereas nickel-treated rats showed a greater improvement with L-ascorbic acid. In both groups, combined supplementation with L-ascorbic acid and alpha-tocopherol did not change the percentage improvement in comparison with supplementation with a single vitamin alone.

  16. Acid-base properties of adhesive dental polymers.

    PubMed

    Morra, M

    1993-11-01

    The surface energetics of three resins (polymethylmethacrylate, polyhydroxyethylmethacrylate, and Bis-GMA/triethyleneglycoldimethacrylate) commonly used in adhesive interactions with tooth hard tissues were evaluated according to the Fowkes acid-base theory of interfacial interactions. From the measurement of the contact angle of test acidic and basic liquids on the sample surfaces, the acid-base contribution to the work of adhesion was evaluated. Results show that polyhydroxyethylmethacrylate is a comparatively strong Lewis base, a finding that can explain the important role played by this material in the formulation of dentin adhesive.

  17. 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.

  18. Infiltration of natural caries lesions in relation to their activity status and acid pretreatment in vitro.

    PubMed

    Neuhaus, K W; Schlafer, S; Lussi, A; Nyvad, B

    2013-01-01

    This study aimed at testing how active and inactive enamel caries lesions differ by their degree of resin infiltration, and whether the choice of acid pretreatment plays a crucial role. Four examiners assessed 104 human molars and premolars with noncavitated enamel lesions and classified them as 'active' or 'inactive' using the Nyvad criteria. Forty-five teeth were included in this study after independent unanimous lesion activity assessment. Lesions were cut perpendicularly into 2 halves. Each half lesion was pretreated with either 15% hydrochloric acid or 35% phosphoric acid. The lesions were infiltrated after staining with rhodamine isothiocyanate. Thin sections of 100 µm were prepared and the specimens were bleached with 30% hydrogen peroxide. The specimens were then counterstained with sodium fluorescein, subjected to confocal laser scanning microscopy and analyzed quantitatively. Outcome parameters were maximum and average infiltration depths as well as relative penetration depths and areas. In active lesions no significant difference of percentage maximum penetration depth and percentage average penetration depth between lesions pretreated with hydrochloric or phosphoric acid could be observed. In inactive lesions, however, phosphoric acid pretreatment resulted in significantly lower penetration compared to hydrochloric acid pretreatment. Surface conditioning with hydrochloric acid led to similar infiltration results in active and inactive lesions. Moreover, inactive lesions showed greater variability in all assessed infiltration parameters than did active lesions. In conclusion, caries lesion activity and acid pretreatment both influenced the infiltration. The use of phosphoric acid to increase permeability of the surface layer of active lesions should be further explored.

  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. 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.

  1. Boronic acid-tethered amphiphilic hyaluronic acid derivative-based nanoassemblies for tumor targeting and penetration.

    PubMed

    Jeong, Jae Young; Hong, Eun-Hye; Lee, Song Yi; Lee, Jae-Young; Song, Jae-Hyoung; Ko, Seung-Hak; Shim, Jae-Seong; Choe, Sunghwa; Kim, Dae-Duk; Ko, Hyun-Jeong; Cho, Hyun-Jong

    2017-02-16

    (3-Aminomethylphenyl)boronic acid (AMPB)-installed hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated for tumor-targeted delivery. The amine group of AMPB was conjugated to the carboxylic acid group of hyaluronic acid (HA) via amide bond formation, and synthesis was confirmed by spectroscopic methods. HACE-AMPB/MB NPs with a 239-nm mean diameter, narrow size distribution, negative zeta potential, and >90% drug encapsulation efficiency were fabricated. Exposed AMPB in the outer surface of HACE-AMPB NPs (in the aqueous environment) may react with sialic acid of cancer cells. The improved cellular accumulation efficiency, in vitro antitumor efficacy, and tumor penetration efficiency of HACE-AMPB/MB NPs, compared with HACE/MB NPs, in MDA-MB-231 cells (CD44 receptor-positive human breast adenocarcinoma cells) may be based on the CD44 receptor-mediated endocytosis and phenylboronic acid-sialic acid interaction. Enhanced in vivo tumor targetability, infiltration efficiency, and antitumor efficacies of HACE-AMPB NPs, compared with HACE NPs, were observed in a MDA-MB-231 tumor-xenografted mouse model. In addition to passive tumor targeting (based on an enhanced permeability and retention effect) and active tumor targeting (interaction between HA and CD44 receptor), the phenylboronic acid-sialic acid interaction can play important roles in augmented tumor targeting and penetration of HACE-AMPB NPs. STATEMENT OF SIGNIFICANCE: (3-Aminomethylphenyl)boronic acid (AMPB)-tethered hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated and their tumor targeting and penetration efficiencies were assessed in MDA-MB-231 (CD44 receptor-positive human adenocarcinoma) tumor models. MB, which exhibited antitumor efficacies via the inhibition of angiogenesis and hypoxia inducible factor (HIF)-1, was entrapped in HACE-AMPB NPs in this study. Phenylboronic acid located in the outer surface

  2. The Debate over Acid Precipitation--Opposing Views--Status of Research.

    DTIC Science & Technology

    1981-09-11

    effects of acid deposition on terrestrial ecosystems. This contrasts with the general agreement among scientists that oxides of sulfur and nitro - gen...Altsnuller and G.A. McBean, Co-chairman, Nov. 148U, p. 1I. 2/Peter E. Coffee , "Long-Range Transport of Acidic Pollutants to New York," in Proceedings of

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Developmental aspects and factors influencing the synthesis and status of ascorbic Acid in the pig.

    PubMed

    Mahan, D C; Ching, S; Dabrowski, K

    2004-01-01

    Ascorbic acid synthesis in the pig occurs at mid-pregnancy, but activity of the enzyme l-gulono-gamma-lactone oxidase (GLO) declines thereafter during gestation and remains low when the pig nurses the sow. During late gestation the ascorbic acid concentration in the fetus increases, but serum and liver ascorbic acid concentration in the sow declines without affecting the dam's liver GLO activity. It is presumed that as gestation progresses an increased amount of maternal ascorbic acid is transferred to the fetus and to the mammary gland. Colostrum and milk are rich sources of the vitamin and supply the nursing pig with ascorbic acid. The available data suggest that high amounts of ascorbic acid appear to suppress liver GLO activity in the pig. Upon weaning, when exogenous vitamin C is generally not provided, liver GLO activity and serum ascorbic acid increases. During the initial periods postweaning, some reports have indicated growth benefits of supplemental vitamin C. Body tissues differ in their concentrations of ascorbic acid, but tissues of high metabolic need generally have greater concentrations. The corpus luteum in the female, the testis in the male, and the adrenal glands in all pigs contain greater concentrations of the vitamin. Knockout genes preventing ascorbic acid synthesis in pigs have demonstrated poor skeletal and collagen formation and poor antioxidant protection. Under periods of stress ascorbic acid declines in the adrenal, but the pig rapidly recovers to its resting state once the stressor agent is removed. Although there are periods when supplemental vitamin C has been shown to promote pig performance (e.g., during high environmental stress and early postweaning), supplemental vitamin C has not been shown to routinely enhance pig performance.

  8. 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)

  9. Polyunsaturated Fatty Acid (PUFA) Status in Pregnant Women: Associations with Sleep Quality, Inflammation, and Length of Gestation

    PubMed Central

    Christian, Lisa M.; Blair, Lisa M.; Porter, Kyle; Lower, Mary; Cole, Rachel M.; Belury, Martha A.

    2016-01-01

    Mechanistic pathways linking maternal polyunsaturated fatty acid (PUFA) status with gestational length are poorly delineated. This study examined whether inflammation and sleep quality serve as mediators, focusing on the antiinflammatory ω-3 docosahexaenoic acid (DHA; 22:6n3) and proinflammatory ω-6 arachidonic acid (AA; 20:4n6). Pregnant women (n = 135) provided a blood sample and completed the Pittsburgh Sleep Quality Index (PSQI) at 20–27 weeks gestation. Red blood cell (RBC) fatty acid levels were determined by gas chromatography and serum inflammatory markers [interleukin (IL)-6, IL-8, tumor necrosis factor-α, IL-1β, and C-reactive protein] by electrochemiluminescence using high sensitivity kits. Both higher serum IL-8 (95% CI = 0.10,3.84) and poor sleep (95% CI = 0.03,0.28) served as significant mediators linking lower DHA:AA ratios with shorter gestation. Further, a serial mediation model moving from the DHA:AA ratio → sleep → IL-8 → length of gestation was statistically significant (95% CI = 0.02, 0.79). These relationships remained after adjusting for depressive symptoms, age, BMI, income, race, and smoking. No interactions with race were observed in relation to length of gestation as a continuous variable. However, a significant interaction between race and the DHA:AA ratio in predicting preterm birth was observed (p = 0.049); among African Americans only, odds of preterm birth decreased as DHA:AA increased (p = 0.048). These data support a role for both inflammatory pathways and sleep quality in linking less optimal RBC PUFA status with shorter gestation in African American and European American women and suggest that African-Americans have greater risk for preterm birth in the context of a low DHA:AA ratio. PMID:26859301

  10. 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.

  11. 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.

  12. 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.…

  13. 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.

  14. Synthesis of polyacrylic-acid-based thermochromic polymers

    NASA Astrophysics Data System (ADS)

    Srivastava, Jyoti; Alam, Sarfaraz; Mathur, G. N.

    2003-10-01

    Smart materials respond to environmental stimuli with particular changes in some variables (for example temperature, pressure and electric field etc), for that reason they are often called responsive materials. In the present work, we have synthesized thermochromic polymer based on poly acrylic acid cobalt chloride (CoCl2) and phosphoric acid (H3PO4) that visually and reversibly changes color in the temperature range (70 - 130°C). These thermochromic materials can be used as visual sensors of temperature. Thermochromic polymers are based on polyacrylic acid and CoCl2 complex.

  15. 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.

  16. 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.

  17. Dopamine receptor alterations in female rats with diet-induced decreased brain docosahexaenoic acid (DHA): interactions with reproductive status

    PubMed Central

    Davis, Paul F.; Ozias, Marlies K.; Carlson, Susan E.; Reed, Gregory A.; Winter, Michelle K.; McCarson, Kenneth E.; Levant, Beth

    2010-01-01

    Decreased tissue levels of n-3 (omega-3) fatty acids, particularly docosahexaenoic acid (DHA), are implicated in the etiologies of non-puerperal and postpartum depression. This study examined the effects of a diet-induced loss of brain DHA content and concurrent reproductive status on dopaminergic parameters in adult female Long–Evans rats. An α-linolenic acid-deficient diet and breeding protocols were used to produce virgin and parous female rats with cortical phospholipid DHA levels 20–22% lower than those fed a control diet containing adequate α-linolenic acid. Decreased brain DHA produced a significant main effect of decreased density of ventral striatal D2-like receptors. Virgin females with decreased DHA also exhibited higher density of D1-like receptors in the caudate nucleus than virgin females with normal DHA. These receptor alterations are similar to those found in several rodent models of depression, and are consistent with the proposed hypodopaminergic basis for anhedonia and motivational deficits in depression. PMID:20670471

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

    PubMed

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

    2016-04-01

    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 10μM 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 96h 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 72h was enhanced by decreasing SOD activity using siRNA directed at MnSOD. Finally, treatment with ATRA for 96h 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.

  19. Attenuation of kainic acid-induced status epilepticus by inhibition of endocannabinoid transport and degradation in guinea pigs.

    PubMed

    Shubina, Liubov; Aliev, Rubin; Kitchigina, Valentina

    2015-03-01

    Status epilepticus (SE) is a medical emergency associated with a high rate of mortality if not treated promptly. Exogenous and endogenous cannabinoids have been shown to possess anticonvulsant properties both in vivo and in vitro. Here we study the influence of endocannabinoid metabolism on the development of kainic acid-induced SE in guinea pigs. For this purpose, the inhibitors of endocannabinoid transport, AM404, and enzymatic (fatty acid amide hydrolase) degradation, URB597, were applied. Cannabinoid CB1 receptor antagonist, AM251, was also tested. Animal behavior as well as local electric field potentials in four structures: medial septum, hippocampus, entorhinal cortex and amygdala were analyzed when AM404 (120nmol), URB597 (4.8nmol) or AM251 (20nmol) were administrated alone or together with 0.4μg of kainic acid. All substances were injected i.c.v. AM404, URB597 or AM251 administered alone did not alter markedly local field potentials of all four studied structures in the long-term compared with their basal activity. AM404 and URB597 significantly alleviated kainic acid-induced SE, decreasing behavioral manifestations, duration of seizure events and SE in general without changing the amplitude of local field potentials. AM251 did not produce distinct effects on SE in terms of our experimental paradigm. There was no apparent change of the seizure initiation pattern when kainic acid was coadministrated with AM404, URB597 or AM251. The present study provides electrophysiologic and behavioral evidences that inhibition of endocannabinoid metabolism plays a protective role against kainic acid-induced SE and may be employed for therapeutic purposes. Further investigations of the influences of cannabinoid-related compounds on SE genesis and especially epileptogenesis are required.

  20. 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.

  1. 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.

  2. 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".

  3. HF acid blends based on formation conditions eliminate precipitation problems

    SciTech Connect

    Gdanski, R.; Shuchart, C.

    1997-03-01

    Formulating HCl-HF acid blends based on the mineralogy and temperature of a formation can increase the success of hydrofluoric acid (HF) treatments. Sodium and potassium in the structures of formation minerals can cause precipitation and matrix plugging problems during acidizing. Slight modifications of the acid blend used in the treatment can help eliminate fluosilicate precipitation. Researchers recently conducted tests to determine how acid blends react in different formations under varying temperatures. The results of the tests indicate that the minimum HCl:HF ratio in an acid blend is 6-to-1, and the optimum ratio is 9-to-1. Regular mud acid (12% HCl-3% HF) has been used successfully for years to enhance production in sandstone formations. By the 1980s, operators began to vary the concentration of HF and HCl acids to solve excessive sanding problems in sandstone. The paper discusses treatment problems, formation characteristics, alumino-silicate scaling, research results, brine compatibility, optimum treatment, and acid volume guidelines.

  4. Fatty acid profile of colostrum and milk of ewes supplemented with fish meal and the subsequent plasma fatty acid status of their lambs.

    PubMed

    Or-Rashid, M M; Fisher, R; Karrow, N; Alzahal, O; McBride, B W

    2010-06-01

    increased over time (P = 0.001) for the lambs nursing ewes fed the fish-meal-supplemented diet. The present findings suggest that the concentrations of docosahexaenoic acid in ewe colostrum and milk can be enhanced through diet supplementation with fish meal. The docosahexaenoic acid status of their suckling lambs can also be further enhanced, and this may contribute to improve neural tissue development and overall performance of suckling lambs.

  5. 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.

  6. 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

  7. Metabolic engineering of Saccharomyces cerevisiae for production of carboxylic acids: current status and challenges.

    PubMed

    Abbott, Derek A; Zelle, Rintze M; Pronk, Jack T; van Maris, Antonius J A

    2009-12-01

    To meet the demands of future generations for chemicals and energy and to reduce the environmental footprint of the chemical industry, alternatives for petrochemistry are required. Microbial conversion of renewable feedstocks has a huge potential for cleaner, sustainable industrial production of fuels and chemicals. Microbial production of organic acids is a promising approach for production of chemical building blocks that can replace their petrochemically derived equivalents. Although Saccharomyces cerevisiae does not naturally produce organic acids in large quantities, its robustness, pH tolerance, simple nutrient requirements and long history as an industrial workhorse make it an excellent candidate biocatalyst for such processes. Genetic engineering, along with evolution and selection, has been successfully used to divert carbon from ethanol, the natural endproduct of S. cerevisiae, to pyruvate. Further engineering, which included expression of heterologous enzymes and transporters, yielded strains capable of producing lactate and malate from pyruvate. Besides these metabolic engineering strategies, this review discusses the impact of transport and energetics as well as the tolerance towards these organic acids. In addition to recent progress in engineering S. cerevisiae for organic acid production, the key limitations and challenges are discussed in the context of sustainable industrial production of organic acids from renewable feedstocks.

  8. Modulation of redox status in human lung cell lines by organoselenocompounds: selenazolidines, selenomethionine and methylseleninic acid

    PubMed Central

    Poerschke, Robyn L.; Franklin, Michael R.; Moos, Philip J.

    2008-01-01

    Cancer prevention strategies utilizing selenium-containing compounds have demonstrated reduced cancer mortality and efficacy for some cancer types but considerable differences in cellular effects exist among the selenocompounds employed. The variability of the effects on cell viability, redox modulation, and disruption of subcellular compartments by the conventional selenium-containing amino acid, selenomethionine, the oxidized selenosugar metabolite, methylseleninic acid, and selenazolidines was investigated in A549 and BEAS-2B human lung cell lines. Selenomethionine had little effect whereas methylseleninic acid increased cellular thiols and stress in the endoplasmic reticulum. The cyclohexylselenazolidine increased mild oxidative stress in the adenocarcinoma cell line, A549, but the effects were attenuated in the normal, but virally transformed cell line, BEAS-2B. These data demonstrate that all selenocompounds are not equal and that the form of the organic selenocompound is a major determinant in the expected cellular response. PMID:18768157

  9. Combined Spectral Index to Improve Ground-Based Estimates of Nitrogen Status in Dryland Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent studies have demonstrated the usefulness of the single ratio Normalized Difference Vegetation Index (NDVI) and ground-based remote sensing for estimating crop yield potential and basing in-season nitrogen (N) fertilizer application. The NDVI is positively related to crop N status and leaf ar...

  10. 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

  11. A balanced review of the status T cell-based therapy against cancer

    PubMed Central

    Marincola, Francesco M

    2005-01-01

    A recent commentary stirred intense controversy over the status of anti-cancer immunotherapy. The commentary suggested moving beyond current anti-cancer vaccines since active-specific immunization failed to match expectations toward a more aggressive approach involving the adoptive transfer of in vitro expanded tumor antigen-specific T cells. Although the same authors clarified their position in response to others' rebuttal more discussion needs to be devoted to the current status of T cell-based anti-cancer therapy. The accompanying publications review the status of adoptive transfer of cancer vaccines on one hand and active-specific immunization on the other. Hopefully, reading these articles will offer a balanced view of the current status of antigen-specific ant-cancer therapies and suggest future strategies to foster unified efforts to complement either approach with the other according to specific biological principles. PMID:15831096

  12. A non-lethal measure of smolt status of juvenile steelhead based on body morphology

    USGS Publications Warehouse

    Beeman, John W.; Rondorf, D.W.; Tilson, M.E.; Venditti, D.A.

    1995-01-01

    A nonlethal morphometric method to assess smolt status of juvenile steelhead Oncorhynchus mykiss was validated. Fish were collected from hatcheries before release and during their seaward migration in a large river system. Fifteen anatomical landmarks were digitized from photographs of each fish, resulting in 34 morphometric characters based on a truss network. Principal component and canonical discriminant function analyses were used to assess smolt status. A single canonical variate was significantly correlated with gill Na+,K+-ATPase activity, a commonly used measure of smolt status. This nonlethal method may be a useful measure of smolt status when sacrificing fish is not desirable or possible; it requires little training to perform, but it does require a larger sample size than some other methods.

  13. Amino acid profile of milk-based infant formulas.

    PubMed

    Viadel, B; Alegriá, A; Farré, R; Abellán, P; Romero, F

    2000-09-01

    The protein content and amino acid profile of three milk-based infant formulas, two of which were powdered (adapted and follow-on) and the third liquid, were determined to check their compliance with the EU directive and to evaluate whether or not they fulfil an infant's nutritional needs. To obtain the amino acid profile proteins were subjected to acid hydrolysis, prior to which the sulfur-containing amino acids were oxidized with performic acid. The amino acids were derivatized with phenylisothiocyanate (PITC) and then determined by ion-pair reverse phase high performance liquid chromatography (HPLC) In the case of tryptophan a basic hydrolysis was applied and there was no need of derivatization. The protein contents of the analysed formulas were in the ranges established by the EU directive for these products and the amino acid contents were in the ranges reported by other authors for these types of formulas. In all cases the tryptophan content determined the value of the chemical score, which was always lower than 80% of the reference protein but in the ranges reported by other authors. The analysed adapted infant formula provides amino acids in amounts higher than the established nutritional requirements.

  14. 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.

  15. 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%.

  16. 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.

  17. 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…

  18. 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…

  19. Hard and soft acids and bases: atoms and atomic ions.

    PubMed

    Reed, James L

    2008-07-07

    The structural origin of hard-soft behavior in atomic acids and bases has been explored using a simple orbital model. The Pearson principle of hard and soft acids and bases has been taken to be the defining statement about hard-soft behavior and as a definition of chemical hardness. There are a number of conditions that are imposed on any candidate structure and associated property by the Pearson principle, which have been exploited. The Pearson principle itself has been used to generate a thermodynamically based scale of relative hardness and softness for acids and bases (operational chemical hardness), and a modified Slater model has been used to discern the electronic origin of hard-soft behavior. Whereas chemical hardness is a chemical property of an acid or base and the operational chemical hardness is an experimental measure of it, the absolute hardness is a physical property of an atom or molecule. A critical examination of chemical hardness, which has been based on a more rigorous application of the Pearson principle and the availability of quantitative measures of chemical hardness, suggests that the origin of hard-soft behavior for both acids and bases resides in the relaxation of the electrons not undergoing transfer during the acid-base interaction. Furthermore, the results suggest that the absolute hardness should not be taken as synonymous with chemical hardness but that the relationship is somewhat more complex. Finally, this work provides additional groundwork for a better understanding of chemical hardness that will inform the understanding of hardness in molecules.

  20. Ionic liquid supported acid/base-catalyzed production of biodiesel.

    PubMed

    Lapis, Alexandre A M; de Oliveira, Luciane F; Neto, Brenno A D; Dupont, Jairton

    2008-01-01

    The transesterification (alcoholysis) reaction was successfully applied to synthesize biodiesel from vegetable oils using imidazolium-based ionic liquids under multiphase acidic and basic conditions. Under basic conditions, the combination of the ionic liquid 1-n-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMINTf2), alcohols, and K2CO3 (40 mol %) results in the production of biodiesel from soybean oil in high yields (>98%) and purity. H2SO4 immobilized in BMINTf2 efficiently promotes the transesterification reaction of soybean oil and various primary and secondary alcohols. In this multiphase process the acid is almost completely retained in the ionic liquid phase, while the biodiesel forms a separate phase. The recovered ionic liquid containing the acid could be reused at least six times without any significant loss in the biodiesel yield or selectivity. In both catalytic processes (acid and base), the reactions proceed as typical multiphasic systems in which the formed biodiesel accumulates as the upper phase and the glycerol by-product is selectively captured by the alcohol-ionic liquid-acid/base phase. Classical ionic liquids such as 1-n-butyl-3-methylimidazolium tetrafluoroborate and hexafluorophosphate are not stable under these acidic or basic conditions and decompose.

  1. Does folic acid supplementation prevent or promote colorectal cancer? Results from model-based predictions.

    PubMed

    Luebeck, E Georg; Moolgavkar, Suresh H; Liu, Amy Y; Boynton, Alanna; Ulrich, Cornelia M

    2008-06-01

    Folate is essential for nucleotide synthesis, DNA replication, and methyl group supply. Low-folate status has been associated with increased risks of several cancer types, suggesting a chemopreventive role of folate. However, recent findings on giving folic acid to patients with a history of colorectal polyps raise concerns about the efficacy and safety of folate supplementation and the long-term health effects of folate fortification. Results suggest that undetected precursor lesions may progress under folic acid supplementation, consistent with the role of folate role in nucleotide synthesis and cell proliferation. To better understand the possible trade-offs between the protective effects due to decreased mutation rates and possibly concomitant detrimental effects due to increased cell proliferation of folic acid, we used a biologically based mathematical model of colorectal carcinogenesis. We predict changes in cancer risk based on timing of treatment start and the potential effect of folic acid on cell proliferation and mutation rates. Changes in colorectal cancer risk in response to folic acid supplementation are likely a complex function of treatment start, duration, and effect on cell proliferation and mutations rates. Predicted colorectal cancer incidence rates under supplementation are mostly higher than rates without folic acid supplementation unless supplementation is initiated early in life (before age 20 years). To the extent to which this model predicts reality, it indicates that the effect on cancer risk when starting folic acid supplementation late in life is small, yet mostly detrimental. Experimental studies are needed to provide direct evidence for this dual role of folate in colorectal cancer and to validate and improve the model predictions.

  2. 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.

  3. 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.

  4. Historical perspective on the role of the kidney in acid-base regulation.

    PubMed

    Smogorzewski, Miroslaw J

    2009-01-01

    Early observations on the acidity of normal urine by J. B. von Helmont (1527-1644) and on urine content of sulfate, phosphate and carbonate by J. J. Berzelius (1779-1848), followed by the studies of Bence Jones (1813-1878) on the connection between food, nutrition and urine acidity, pointed to the role of the kidney in regulation of acid-base status in humans and animals. The next important steps in this field of science were studies by F. Walter (1877) on decreased "alkali" in blood and increased ammonia in the urine of dogs after infusion into their blood of hydrochloric acid, and the observations of B. Naunyn (1939-1925) and O. Minkowski (1853-1931) on the presence of beta-hydroxybutyric acid in urine and on increased ammonia excretion in urine from patients with diabetic coma. Also it was found that patients with uremia had decreased titratable "alkali' in blood (R. von Jaksch 1855-1947) and reduced ability to excrete ammonia (W. W. Palmer and L. J. Henderson 1915). Finally, studies by R. F. Pitts (1908-1977) defined the role of the kidney in reabsorption of bicarbonate in the tubules and linked hydrogen secretion to sodium excretion in the urine.

  5. 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.

  6. 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.

  7. Free amino acids as indicators of nutritional status of silver bream (Vimba vimba), when using commercial and purified diets.

    PubMed

    Kwasek, Karolina; Zhang, Yongfang; Hliwa, Piotr; Gomułka, Piotr; Ostaszewska, Teresa; Dabrowski, Konrad

    2009-06-01

    Studies on larval rearing of silver bream (Vimba vimba), a migratory cyprinid fish have addressed on limited scale larval and juvenile rearing using commercial and semipurified diets along with live feeds, such as brine shrimp Artemia nauplii. The objectives of the present study were (1) to determine whether experimental, protein-, peptide-, free amino acid-based diets are adequate for larval silver bream, a stomachless fish, (2) to evaluate whether commercial and purified diets are comparable as the first/exclusive feed for growth and survival of silver bream, and (3) to examine whether free amino acid concentrations in fish body are potential indicators of availability of amino acid sources. We report here the differences in diets acceptance, fish growth and diet utilization in silver bream in comparison to other cyprinid fishes. We specifically address the response in free amino acids in the body to dietary treatments. Experimental diets included: a commercial Aglo Norse feed, casein-gelatin based diet (CG), free amino acid mixture diet (FAA), dipeptide (PP), dipeptide-protein (PP50) based diet, and dipeptide diet without arginine (NoArg). In addition, live Artemia were offered to 3 groups and "fasting" control treatment was included during 3 week long trial. Fish offered Artemia overperformed those offered formulated diets both in terms of mass (80.7+/-26.3 mg) and survival (97.2%). We also indicate that commercial and purified diets are comparable as the first/exclusive feed for growth and survival of silver bream. Our experiment also showed that the whole body free amino acid concentrations of 9 indispensable amino acids (IDAA) out of 10 (His, Thr, Arg, Val, Met, Ile, Leu, Trp, Lys) in the PP50 group was the highest among 7 diet treatments and the totalfree amino acid concentration, total dispensable amino acids (DAA) and total IDAA of the PP50 diet fed fish showed the same trend. This may indicate that diets based on 50% of dipeptides and 50% of protein are

  8. 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

  9. 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.

  10. Socioeconomic status in relation to Parkinson's disease risk and mortality: A population-based prospective study.

    PubMed

    Yang, Fei; Johansson, Anna L V; Pedersen, Nancy L; Fang, Fang; Gatz, Margaret; Wirdefeldt, Karin

    2016-07-01

    Little is known about the role of socioeconomic status in relation to Parkinson's disease (PD) risk, and no study has investigated whether the impact of socioeconomic status on all-cause mortality differs between individuals with and without PD.In this population-based prospective study, over 4.6 million Swedish inhabitants who participated in the Swedish census in 1980 were followed from 1981 to 2010. The incidence rate of PD and incidence rate ratio were estimated for the association between socioeconomic status and PD risk. Age-standardized mortality rate and hazard ratio (HR) were estimated for the association between socioeconomic status and all-cause mortality for individuals with and without PD.During follow-up, 66,332 incident PD cases at a mean age of 76.0 years were recorded. Compared to individuals with the highest socioeconomic status (high nonmanual workers), all other socioeconomic groups (manual or nonmanual and self-employed workers) had a lower PD risk. All-cause mortality rates were higher in individuals with lower socioeconomic status compared with high nonmanual workers, but relative risks for all-cause mortality were lower in PD patients than in non-PD individuals (e.g., for low manual workers, HR: 1.12, 95% confidence interval [CI]: 1.09-1.15 for PD patients; HR: 1.36, 95% CI: 1.35-1.36 for non-PD individuals).Individuals with lower socioeconomic status had a lower PD incidence compared to the highest socioeconomic group. Lower socioeconomic status was associated with higher all-cause mortality among individuals with and without PD, but such impact was weaker among PD patients.

  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. FBG-Based Monitoring of Geohazards: Current Status and Trends.

    PubMed

    Zhu, Hong-Hu; Shi, Bin; Zhang, Cheng-Cheng

    2017-02-24

    In recent years, natural and anthropogenic geohazards have occured frequently all over the world, and field monitoring is becoming an increasingly important task to mitigate these risks. However, conventional geotechnical instrumentations for monitoring geohazards have a number of weaknesses, such as low accuracy, poor durability, and high sensitivity to environmental interferences. In this aspect, fiber Bragg grating (FBG), as a popular fiber optic sensing technology, has gained an explosive amount of attention. Based on this technology, quasi-distributed sensing systems have been established to perform real-time monitoring and early warning of landslides, debris flows, land subsidence, earth fissures and so on. In this paper, the recent research and development activities of applying FBG systems to monitor different types of geohazards, especially those triggered by human activities, are critically reviewed. The working principles of newly developed FBG sensors are briefly introduced, and their features are summarized. This is followed by a discussion of recent case studies and lessons learned, and some critical problems associated with field implementation of FBG-based monitoring systems. Finally the challenges and future trends in this research area are presented.

  13. FBG-Based Monitoring of Geohazards: Current Status and Trends

    PubMed Central

    Zhu, Hong-Hu; Shi, Bin; Zhang, Cheng-Cheng

    2017-01-01

    In recent years, natural and anthropogenic geohazards have occured frequently all over the world, and field monitoring is becoming an increasingly important task to mitigate these risks. However, conventional geotechnical instrumentations for monitoring geohazards have a number of weaknesses, such as low accuracy, poor durability, and high sensitivity to environmental interferences. In this aspect, fiber Bragg grating (FBG), as a popular fiber optic sensing technology, has gained an explosive amount of attention. Based on this technology, quasi-distributed sensing systems have been established to perform real-time monitoring and early warning of landslides, debris flows, land subsidence, earth fissures and so on. In this paper, the recent research and development activities of applying FBG systems to monitor different types of geohazards, especially those triggered by human activities, are critically reviewed. The working principles of newly developed FBG sensors are briefly introduced, and their features are summarized. This is followed by a discussion of recent case studies and lessons learned, and some critical problems associated with field implementation of FBG-based monitoring systems. Finally the challenges and future trends in this research area are presented. PMID:28245551

  14. 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.

  15. 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.

  16. Using Blood Indexes to Predict Overweight Statuses: An Extreme Learning Machine-Based Approach.

    PubMed

    Chen, Huiling; Yang, Bo; Liu, Dayou; Liu, Wenbin; Liu, Yanlong; Zhang, Xiuhua; Hu, Lufeng

    2015-01-01

    The number of the overweight people continues to rise across the world. Studies have shown that being overweight can increase health risks, such as high blood pressure, diabetes mellitus, coronary heart disease, and certain forms of cancer. Therefore, identifying the overweight status in people is critical to prevent and decrease health risks. This study explores a new technique that uses blood and biochemical measurements to recognize the overweight condition. A new machine learning technique, an extreme learning machine, was developed to accurately detect the overweight status from a pool of 225 overweight and 251 healthy subjects. The group included 179 males and 297 females. The detection method was rigorously evaluated against the real-life dataset for accuracy, sensitivity, specificity, and AUC (area under the receiver operating characteristic (ROC) curve) criterion. Additionally, the feature selection was investigated to identify correlating factors for the overweight status. The results demonstrate that there are significant differences in blood and biochemical indexes between healthy and overweight people (p-value < 0.01). According to the feature selection, the most important correlated indexes are creatinine, hemoglobin, hematokrit, uric Acid, red blood cells, high density lipoprotein, alanine transaminase, triglyceride, and γ-glutamyl transpeptidase. These are consistent with the results of Spearman test analysis. The proposed method holds promise as a new, accurate method for identifying the overweight status in subjects.

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

    PubMed

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

    2013-11-07

    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.

  18. 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.

  19. Status of advanced propulsion for space based orbital transfer vehicle

    NASA Technical Reports Server (NTRS)

    Cooper, L. P.; Scheer, D. D.

    1986-01-01

    A new Orbital Transfer Vehicle (OTV) propulsion system will be required to meet the needs of space missions beyond the mid-1990's. As envisioned, the advanced OTV will be used in conjunction with Earth-to-orbit vehicles, Space Station, and Orbit Maneuvering Vehicle. The OTV will transfer men, large space structures, and conventional payloads between low Earth and higher energy orbits. Space probes carried by the OTV will continue the exploration of the solar system. When lunar bases are established, the OTV will be their transportation link to Earth. NASA is currently funding the development of technology for advanced propulsion concepts for future Orbital Transfer Vehicles. Progress in key areas during 1986 is presented.

  20. Status of advanced propulsion for space based orbital transfer vehicle

    NASA Technical Reports Server (NTRS)

    Cooper, Larry P.; Scheer, Dean D.

    1986-01-01

    A new Orbital Transfer Vehicle (OTV) propulsion system will be required to meet the needs of space missions beyond the mid-1990's. As envisioned, the advanced OTV will be used in conjunction with earth-to-orbit vehicles, Space Station, and Orbit Maneuvering Vehicle. The OTV will transfer men, large space structures, and conventional payloads between low earth and higher energy orbits. Space probes carried by the OTV will continue the exploration of the solar system. When lunar bases are established, the OTV will be their transportation link to earth. NASA is currently funding the development of technology for advanced propulsion concepts for future Orbital Transfer Vehicles. Progress in key areas during 1986 is presented.

  1. Influence of various amounts of fumaric acid on performance and parameters of the acid-base balance of growing bulls fed with grass or maize silage.

    PubMed

    Remling, Nicole; Hachenberg, Sabrina; Meyer, Ulrich; Höltershinken, Martin; Flachowsky, Gerhard; Dänicke, Sven

    2011-10-01

    The aim of the present study was to determine the effects of the potential methane reducer fumaric acid on the fattening performance and acid-base balance of growing bulls fed two different silage types as roughage (maize and grass silage). A total of 62 fattening bulls (German Holstein breed, initial body weight: 266 +/- 42 kg), randomly assigned to eight feeding groups, received four levels of fumaric acid (0, 100, 200 or 300 g/d) at each silage type. The daily feed and water intake and the live weight were measured over the whole testing period of 280 days. In blood samples, blood cells and blood gases as a parameter of acid-base status were analysed. Feed and faeces were collected to determine the apparent nutrient digestibility. Five animals from each group fed maize or grass silage, supplemented with 0 g or 300 g fumaric acid, were slaughtered at 580 kg body weight. After slaughter, rumen fluid pH was measured and dressing percentage was calculated. Neither the total feed intake (8.81 +/- 0.07 kg/d) nor the daily weight gain (1277 +/- 24 g/d) was influenced significantly by treatments. Fumaric acid supplementation did not influence the erythrocyte count or the blood gas concentration. The silage type significantly influenced the apparent digestibility of the whole diet. The dressing percentage was slightly higher (p < 0.1) after fumaric acid supplementation. No signs of an incompatibility to fumaric acid on the animals were observed over the whole experimental period. However, it seems to be necessary to conduct more long-term studies with different silage types and addition of organic acids combined with direct measurements of methane.

  2. 78 FR 21100 - Grant of Authority for Subzone Status; Dow Corning Corporation (Silicon-Based Products); Midland, MI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... Foreign-Trade Zones Board Grant of Authority for Subzone Status; Dow Corning Corporation (Silicon-Based... subzone with certain manufacturing authority at the silicon- based products manufacturing facility of Dow... authority for subzone status for activity related to the manufacturing of silicon-based products at...

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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…

  9. 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...

  10. Fostering Engagement for Students from Low-Socioeconomic Status Backgrounds Using Project-Based Mathematics

    ERIC Educational Resources Information Center

    Heyl, Allison

    2008-01-01

    In overcrowded urban high schools, students are dealing with many issues in and out of school. Issues at home paired with math curriculum that does not seem relevant to their lives, leads to a lack of engagement in the classroom. This research poses the question: How can project-based algebra engage low-socioeconomic status high school students?…

  11. 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…

  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. 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…

  14. Evaluation of trace element and mineral status and related to levels of amino acid in children with phenylketonuria.

    PubMed

    Gok, Fazilet; Ekin, Suat; Dogan, Murat

    2016-07-01

    The aim of the present study was to examine trace elements (Zn, Cu, Mn, Se, Fe, Co, Cr, Ni, Cd, Pb), minerals (Ca, Mg, K), amino acids status in children with phenylketonuria and also whether they were correlated with each other in phenylketonuric patients. It has been found out that the HPA group was significantly lower than the control group with regards to Zn, Se, K, Ca, Mg and Zn/Cr levels (p<0.001, p<0.01, p<0.001, p<0.01, p<0.01 and p<0.001 respectively). In the patients with HPA, significantly strong positive correlations were observed between magnesium and calcium (r=0.791; p=0.001), also, indicates negative significant correlation between the concentrations of magnesium and phenylalanine (r=-0.591; p=0.026). The results of this study showed that, in the HPA group, phenylalanine-Mg relationship found, the presence of disease will in the evaluation of phenylalanine and other amino acids, together with the value of magnesium is required to consider.

  15. Comparative Studies of Salivary and Blood Sialic Acid, Lipid Peroxidation and Antioxidative Status in Oral Squamous Cell Carcinoma (OSCC)

    PubMed Central

    Rasool, Mahmood; Khan, Saima Rubab; Malik, Arif; Khan, Khalid Mahmood; Zahid, Sara; Manan, Abdul; Qazi, Mahmood Husain; Naseer, Muhammad Imran

    2014-01-01

    Objective : Oral squamous cell carcinoma (OSCC) is considered to be a serious life threatening issue for almost two decades. The objective of this study was to evaluate the over production of lipid peroxidation (LPO) byproducts and disturbances in antioxidant defense system in the pathogenesis of oral cancer. Methods : Lipid peroxidation and antioxidant status in OSCC patients were estimated and compared the sensitivity and specificity of circulating biomarkers (MDA, Sialic acid, Catalase, SOD, GSH and Neuraminidase) with β-2 microglobulin (β-2MG) at different thresholds in blood and saliva using receiver operating characteristics (ROC) curve design. R esults : Our results showed that the levels of MDA and Sialic acid were significantly increased in plasma of OSCC patients as compared to healthy subjects whereas antioxidant level was significantly decreased. Conclusion : ROC analysis indicated that MDA in saliva is a better diagnostic tool as compared to MDA in blood and β-2MG in blood is better diagnostic marker as compared to β-2MG level in saliva. PMID:24948960

  16. Selective increases of extracellular brain concentrations of aromatic and branched-chain amino acids in relation to deterioration of neurological status in acute (ischemic) liver failure.

    PubMed

    Michalak, A; Butterworth, R F

    1997-12-01

    Previous reports based on studies in brain tissue from humans and experimental animals suggest that aromatic amino acids (AAAs) and branched-chain amino acids (BCAA's) accumulate in brain in acute liver failure. In order to assess these changes in relation to the severity of neurological impairment and to the degree of hyperammonemia, AAAs and BCAAs were measured in vivo by cerebral microdialysis in frontal cortex of rats at various stages during the development of hepatic encephalopathy due to acute liver failure resulting from portacaval anastomosis followed by hepatic artery ligation. Extracellular brain concentrations of AAAs and of valine and leucine were elevated 2 to 4-fold following hepatic devascularization and these increases were significantly correlated to arterial ammonia concentration (r= 0.71-0.84, p<0.05). Extracellular concentrations of tyrosine paralleled the deterioration of neurological status in acute liver failure rats. In view of their role as precursors of monoamine neurotransmitters, ammonia-induced alterations of intracellular/extracellular brain concentration ratios for AAAs could account for altered neuronal excitability and contribute to the encephalopathy characteristic of acute liver failure.

  17. 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.

  18. 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.

  19. Evolution of Acid-Base Concept (1917-1984).

    ERIC Educational Resources Information Center

    Gamble, James L., Jr.

    1984-01-01

    Evaluates the accuracy and usefulness of a simpler rationale for teaching acid-base physiology as compared to more complex approaches frequently taught in physiology courses. Also reviews problems of terminology, giving emphasis to the significant effects that the choice of words can have on students' concepts. (JN)

  20. 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)

  1. Linear titration plots for polyfunctional weak acids and bases.

    PubMed

    Midgley, D; McCallum, C

    1976-04-01

    Procedures are derived for obtaining the equivalence volumes in the potentiometric titrations of polyfunctional weak acids and weak bases by a linear titration plot method. The effect of errors in the equilibrium constants on the accuracy is considered. A Fortran program is available to do the calculations.

  2. Dynamic Buffer Capacity in Acid-Base Systems.

    PubMed

    Michałowska-Kaczmarczyk, Anna M; Michałowski, Tadeusz

    The generalized concept of 'dynamic' buffer capacity βV is related to electrolytic systems of different complexity where acid-base equilibria are involved. The resulting formulas are presented in a uniform and consistent form. The detailed calculations are related to two Britton-Robinson buffers, taken as examples.

  3. 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)

  4. 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…

  5. 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…

  6. 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...

  7. 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...

  8. 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...

  9. 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.

  10. Hard and soft acids and bases: small molecules.

    PubMed

    Reed, James L

    2009-08-03

    The operational chemical hardness has been determined for the hydride, chloride, and fluoride derivatives of the anionic atomic bases of the second period. Of interest is the identification of the structure and associated processes that give rise to hard-soft behavior in small molecules. The Pearson Principle of Hard and Soft Acids and Bases has been taken to be the defining statement about hard-soft behavior and as a definition of chemical hardness. Similar to the case for atoms, the molecule's responding electrons have been identified as the structure giving rise to hard-soft behavior, and a relaxation described by a modified Slater model has been identified as the associated process. The responding electrons are the molecule's valence electrons that are not undergoing electron transfer in an acid-base interaction. However, it has been demonstrated that chemical hardness is a local property, and only those responding electrons that are associated with the base's binding atom directly impact chemical hardness.

  11. Controlling Salmonella infection in weanling pigs through water delivery of direct-fed microbials or organic acids. Part I: effects on growth performance, microbial populations, and immune status.

    PubMed

    Walsh, M C; Rostagno, M H; Gardiner, G E; Sutton, A L; Richert, B T; Radcliffe, J S

    2012-01-01

    Pigs (n = 88) weaned at 19 ± 2 d of age were used in a 14-d study to evaluate the effects of water-delivered direct-fed microbials (DFM) or organic acids on growth, immune status, Salmonella infection and shedding, and intestinal microbial populations after intranasal inoculation of Salmonella Typhimurium (10(10) cfu/pig). Pigs were challenged with Salmonella 6 d after commencement of water treatments. Treatments were 1) control diet; 2) control diet + DFM (Enterococcus faecium, Bacillus subtilis, and Bacillus licheniformis) in drinking water at 10(9) cfu/L for each strain of bacteria; 3) control diet + an organic acid-based blend (predominantly propionic, acetic, and benzoic acid) in drinking water at 2.58 mL/L; and 4) control diet + 55 mg/kg of carbadox. Serum samples were taken on d 6, 8, 10, and 14 for determination of tumor necrosis factor α (TNFα) concentrations. Fecal samples were taken on d 0, 5, 7, and 11 for determination of Salmonella shedding and enumeration of coliforms. Pigs were euthanized on d 6, 8, 10, and 14. Intestinal and cecal tissue and digesta and mesenteric lymph nodes were sampled and analyzed for Salmonella. Duodenal, jejunal, and ileal mucosal scrapings were sampled for measurement of mucosal TNFα concentrations. Water delivery of DFM prevented a decline in ADG on d 2 to 6 postchallenge compared with the negative control (P < 0.05). Coliform counts tended to be greater (P = 0.09) in the cecum of the DFM treatment group on d 2 postinfection compared with the negative control and acid treatment groups. However, Salmonella prevalence in the feces, gastrointestinal tract, or lymph nodes was not affected by water delivery of acids or DFM. Serum and mucosal TNFα concentrations were not affected by treatment throughout the study with the exception of ileal concentrations on d 4 postchallenge, which were greater in the negative control group compared with all other treatments (P < 0.05). The in-feed antibiotic was the only treatment that

  12. Becoming an adult: A proposed typology of adult status based on a study of Spanish youths.

    PubMed

    Zacarés, Juan José; Serra, Emilia; Torres, Francisca

    2015-06-01

    Emerging adulthood is a transitional period which has been examined in relatively few studies in Southern European countries. This study has two aims: (1) to determine the features of emerging adulthood in Spain based on criteria for adulthood and experiential dimensions; and (2) to explore whether variations in these criteria are related to gender and adult status (self-classification as an adult and adult role adoption). Participants included 347 young Spanish people, aged 18-30, who completed a questionnaire about their conceptions of adulthood. They used similar criteria for adulthood to other Western countries, placing an extremely strong emphasis on psychological maturity criteria in comparison with role transition indicators. Important variations were observed in both the importance and achievement of criteria for adulthood according to gender and adult status. The results likewise suggest there may be different psychosocial profiles associated with each adult status group. The relevance of this classification to future research in the field of emerging adulthood is discussed.

  13. 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.

  14. Controlling Salmonella infection in weanling pigs through water delivery of direct-fed microbials or organic acids; Part I. Effects on growth performance, microbial populations and immune status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pigs (n=88) weaned at 19 ± 2 d of age were used in a 14 d study to evaluate the effects of water-delivered direct-fed microbials (DFM) or organic acids on immune status, Salmonella infection and shedding, and intestinal microbial populations following a Salmonella Typhimurium challenge. Pigs were ch...

  15. Acid-base thermochemistry of gaseous oxygen and sulfur substituted amino acids (Ser, Thr, Cys, Met).

    PubMed

    Riffet, Vanessa; Frison, Gilles; Bouchoux, Guy

    2011-11-07

    Acid-base thermochemistry of isolated amino acids containing oxygen or sulfur in their side chain (serine, threonine, cysteine and methionine) have been examined by quantum chemical computations. Density functional theory (DFT) was used, with B3LYP, B97-D and M06-2X functionals using the 6-31+G(d,p) basis set for geometry optimizations and the larger 6-311++G(3df,2p) basis set for energy computations. Composite methods CBS-QB3, G3B3, G4MP2 and G4 were applied to large sets of neutral, protonated and deprotonated conformers. Conformational analysis of these species, based on chemical approach and AMOEBA force field calculations, has been used to identify the lowest energy conformers and to estimate the population of conformers expected to be present at thermal equilibrium at 298 K. It is observed that G4, G4MP2, G3B3, CBS-QB3 composite methods and M06-2X DFT lead to similar conformer energies. Thermochemical parameters have been computed using either the most stable conformers or equilibrium populations of conformers. Comparison of experimental and theoretical proton affinities and Δ(acid)H shows that the G4 method provides the better agreement with deviations of less than 1.5 kJ mol(-1). From this point of view, a set of evaluated thermochemical quantities for serine, threonine, cysteine and methionine may be proposed: PA = 912, 919, 903, 938; GB = 878, 886, 870, 899; Δ(acid)H = 1393, 1391, 1396, 1411; Δ(acid)G = 1363, 1362, 1367, 1382 kJ mol(-1). This study also confirms that a non-negligible ΔpS° is associated with protonation of methionine and that the most acidic hydrogen of cysteine in the gas phase is that of the SH group. In several instances new conformers were identified thus suggesting a re-examination of several IRMPD spectra.

  16. Journey Toward Evidence-Based Status: Seeking Admission to Formal Program Registries.

    PubMed

    Stephenson, Amber L

    2016-09-19

    In the past two decades, evidence-based status has been a coveted credential for many nonprofit organizations hoping to legitimize their programs or interventions. Several formal registries exist to provide a collection of health and prevention programs evaluated by experts and deemed "evidence-based." While registries offer positive benefits like allowing for a centralized listing of approved programs, there have been concerns about issues pertaining to the process of obtaining the evidence-based credential. Namely, some of the criticisms include the use of inappropriate study designs, the lack of consistent evaluation of evidence provided in support of programs, as well as program creators being involved in the evaluation that ultimately shows positive program effects. Using focus groups of prevention specialists, this study explores the quest for evidence-based status. The results show themes of vindication, acting as a resource, and perceptions of relevant others informing the deeper meaning of motivation for pursuit of evidence-based status. Additionally, emergent themes of program iteration and evolution inform program preparation. The article shows that while placement on an evidence-based registry is a highly sought-after achievement, many program creators fail to understand the evaluation process for admittance as well as the potential criticisms of the lists.

  17. 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

  18. Effect of thermally oxidized oil and fasting status on the short-term digestibility of ketolinoleic acids and total oxidized fatty acids in rats.

    PubMed

    Olivero-David, Raul; Paduano, Antonello; Fogliano, Vincenzo; Vitaglione, Paola; Bastida, Sara; González-Muñoz, María José; Benedí, Juana; Sacchi, Raffaele; Sánchez-Muniz, Francisco José

    2011-05-11

    Western diets contain substantial amounts of lipid oxidation products. The effects of fasting status and oil oxidation on short-term digestibility of oxidized fatty acids (ox-FA) and ketolinoleic acids (keto-LA) of sunflower oils were evaluated. Twelve rats were fasted overnight for 3 days, whereas another 12 rats had free access to diet. From day 4, and for 4 days, two groups of rats, nonfasted (NFT) and fasted (FT), received 1 g/100 g body weight of sunflower oil reused from 40 deep-frying processes, and two control groups of rats, nonfasted (NFC) and fasted (FC), received the same amount of fresh oil. Ox-FA and keto-LA were determined 5 h after the last administration in the various gastrointestinal compartments together with the intraintestinal MDA. Oil digestibility was highest in NFC and lowest in FT rats. NFT and FT rats had higher (at least P < 0.05) intraintestinal MDA, ox-FA, and keto-LA than NFC and FC; MDA and keto-LA concentrations correlated with each other (P < 0.05). Ox-FA and keto-LA levels found in the gastric lumen suggest that digestion contributes to the formation of these compounds. Total ox-FA and keto-LA were efficiently absorbed during the first 5 h after test oil administration, but poorly absorbed in the case of fresh oils. Oil alteration influenced the digestibility of these compounds more than fasting, although the digestibility of oxidized oil was significantly affected by fasting.

  19. 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.

  20. Fatty acid profiles among the Inuit of Nunavik: current status and temporal change.

    PubMed

    Proust, Françoise; Lucas, Michel; Dewailly, Eric

    2014-05-01

    The Inuit undergo substantial changes in their lifestyle, but few data exist on how these changes occur in biomarkers, such as polyunsaturated fatty acids (PUFAs). Here, we report data from a cross-sectional survey conducted in 2004 among 861 representative Nunavik Inuit adults, in whom FAs were measured in red blood cells (RBCs). FAs were also measured in plasma phospholipids (n=452) to assess temporal trend by comparing plasma PUFAs measured in 1992. Food intakes were estimated using a validated food frequency questionnaire. In 2004, marine food intake was 84±4g/d (±SEM). Adjusted-mean of RBC omega-3 was significantly higher, and omega-6 lower, in older age groups (Ptrend<0.001). In 2004, plasma omega-3 was 25% lower, while omega-6 was 9% higher, compared to 1992. Our study revealed that Nunavik Inuit adults still have high RBC omega-3, but show signs of nutritional transition - as indicated by lower omega-3 and higher trans-fats in RBCs of young compared to older.

  1. Impact of fatty acid status on growth and neurobehavioural development in humans.

    PubMed

    Makrides, Maria; Collins, Carmel T; Gibson, Robert A

    2011-04-01

    Many studies have been conducted to investigate the effect of n-3 long-chain polyunsaturated fatty acid (LCPUFA) supplementation during the perinatal period on the growth and neurobehavioural development of young children. Most of these intervention trials have involved infants from high-income countries, and a significant proportion have investigated supplementation of infant formulas. Generally, supplementation of infant formula for preterm rather than term infants has demonstrated more consistent, positive effects on aspects of neurobehavioural development, while the growth of both term and preterm infants appears unaffected by LCPUFA supplementation. Maternal n-3 LCPUFA supplementation during pregnancy has consistently resulted in modest increases in birth size, and the most recent study suggests that this is also true from women from low-income environments. The effect of maternal supplementation on global neurobehavioural outcomes for children born at term remains unclear, although n-3 LCPUFA supplementation of women expressing milk for their preterm infants does improve their performance on tests of global neurodevelopment. Further work is required to determine whether dietary n-3 LCPUFA is neuroprotective for children from disadvantaged or low-income backgrounds.

  2. Coulometric titration of bases in acetic acid and acetonitrile media.

    PubMed

    Vajgand, V J; Mihajlović, R

    1969-09-01

    The working conditions and the results for coulometric titration of milligram amounts of some bases in 0.1M sodium perchlorate in a mixture of acetic acid and acetic anhydride (1:6), are given. Determinations were made both by coulometric back-titration or direct titration at the platinum anode. Back-titration was done in the catholyte, by coulometric titration of the excess of added perchloric acid. The titration end-point was detected photometrically with Crystal Violet as indicator. The direct titration of bases was done at the platinum anode, in the same electrolyte, to which hydroquinone was added as anode depolarizer and as the source of hydrogen ions, Malachite Green being used as indicator. Similarly, bases can be determined in acetonitrile if sodium perchlorate, hydroquinone and Malachite Green are added to the solvent. Errors are below 1 %, and the precision is satisfactory.

  3. 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.

  4. 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.

  5. Effect of low dose ω-3 poly unsaturated fatty acids on cognitive status among older people: a double-blind randomized placebo-controlled study

    PubMed Central

    2014-01-01

    Background Cognitive impairment is a prevalent health problem in older people and its global prevalence tends to increase parallel to the extended life expectancy in world. The beneficial effect of ω-3 PUFAs on cognitive impairment has been demonstrated in some experimental and cohort studies. In this study we aimed to assess the effect of low dose docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) supplementation on cognitive status in the elderly. Methods In a double-blind, randomized placebo-controlled study, 199 individuals aged ≥65 years with normal or mild to moderate cognition impairment were assigned to receive either 180 mg of DHA plus 120 mg of EPA or placebo for 180 days. Cognitive status was assessed using Mini-Mental State Examination (MMSE) and Abbreviated Mental Test (AMT) score. Results MMSE and AMT scores were not different at the time of allocation [18.84 (5.37), 18.55 (5.12), (P = 0.70) and 4.81 (2.79) and 4.64 (2.77), (P = 0.67) respectively] and over 6 months between the ω-3 PUFA- and placebo- treated groups [18.57 (5.21), 18.39 (5.10), (P = 0.80) and 4.64 (2.77) and 4.48 (2.69) and (P = 0.67)]. The participants were categorized based on MMSE score into normal cognition, mild and moderate cognitive impairment. After multivariate adjustment, there was no significant difference among categorized groups regarding the ω-3 PUFA effect except in normal cognition group, that amount of decline in AMT in ω-3 poly unsaturated fatty acids (PUFAs) was less than placebo group. Conclusions It seems that prescription of low dose ω-3 PUFAs for 6 months had no significant beneficial effects on improvement of cognition or prevention of cognitive decline in older people. PMID:24507770

  6. 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

  7. An American knowledge base in England - Alternate implementations of an expert system flight status monitor

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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 has been agreed. Under the agreement, a flight status monitor knowledge base developed at Ames-Dryden has been implemented using the real-time AI (artificial intelligence) toolkit MUSE, which was developed in the UK. Here, the background to the cooperation is described and the details of the flight status monitor and a prototype MUSE implementation are presented. It is noted that the capabilities of the expert-system flight status monitor to monitor data downlinked from the flight test aircraft and to generate information on the state and health of the system for the test engineers provides increased safety during flight testing of new systems. Furthermore, the expert-system flight status monitor provides the systems engineers with ready access to the large amount of information required to describe a complex aircraft system.

  8. Prenatal fatty acid status and immune development: the pathways and the evidence.

    PubMed

    Prescott, Susan L; Dunstan, Janet A

    2007-09-01

    This review explores the effects of dietary long chain polyunsaturated fatty acids (LCPUFA) on various aspects of early immune development and their potential role in the development or the prevention of immune disease. Modern diets have become increasingly rich in n-6 LCPUFA and relatively n-3 LCPUFA deficient. These potentially "pro-inflammatory" dietary changes have clear implications for the immature and developing fetal immune system. It is now well known that immunological abnormalities precede the development of allergic disease and are frequently evident at birth or in the first months of life. This has lead to the hypothesis that potential effects of LCPUFA could be greatest in very early life before immune responses and clinical phenotype are established. Here we summarise the evidence that patterns of LCPUFA exposure in pregnancy can influence aspects of fetal immune in ways that are consistent with the immunological properties of these nutrients in adults. Specifically, human studies have shown that higher levels of n-3 LCPUFA are associated with reduction in neonatal oxidative stress, reduced production of inflammatory leukotienne B4 (LTB4) and altered T cell function. Inverse correlations between n-3 LCPUFA levels and neonatal T cell cytokine production, are consistent with adult studies showing reduction in T cell cytokine production with fish oil supplementation. At this stage the relevance of these effects in the prevention of disease is unclear. Although there have been no effects of postnatal fish oil supplementation (from 6 months of age) on allergy prevention, preliminary studies suggest possible merits in pregnancy and there are ongoing pregnancy intervention studies to address this more definitively.

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

    PubMed

    Reed, James L

    2012-07-05

    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.

  10. 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.

  11. 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

  12. Developing nucleic acid-based electrical detection systems

    PubMed Central

    Gabig-Ciminska, Magdalena

    2006-01-01

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

  13. 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

  14. 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.

  15. 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.

  16. Synthesis and characterization of copolyanhydrides of carbohydrate-based galactaric acid and adipic acid.

    PubMed

    Mehtiö, Tuomas; Nurmi, Leena; Rämö, Virpi; Mikkonen, Hannu; Harlin, Ali

    2015-01-30

    A series of copolyanhydrides, consisting of 2,3,4,5-tetra-O-acetylgalactaric acid (AGA) and adipic acid (AA) as monomer units, was polymerized. Synthesis of AGA monomer consisted of two steps. First, O-acetylation of galactaric acid secondary hydroxyl groups was performed using acetic anhydride as a reagent. Acetic anhydride was then further used as a reagent in the synthesis of diacetyl mixed anhydride of AGA. Polymerizations were conducted as bulk condensation polymerization at 150 °C. Thermal properties of the copolymers varied depending on monomer composition. Increase in the AGA content had a clear increasing effect on the Tg. A similar increasing effect was observed in Tm. The degree of crystallinity decreased as AGA content increased. There was a slightly lowering tendency in the molecular weights of the obtained polymers when the AGA content in the polymerization mixtures increased. The described synthesis route shows that bio-based aldaric acid monomers are potential candidates for the adjustment of thermal properties of polyanhydrides.

  17. Effect of motivational interviewing-based health coaching on employees' physical and mental health status.

    PubMed

    Butterworth, Susan; Linden, Ariel; McClay, Wende; Leo, Michael C

    2006-10-01

    Motivational Interviewing (MI) based health coaching is a relatively new behavioral intervention that has gained popularity in public health because of its ability to address multiple behaviors, health risks, and illness self-management. In this study, 276 employees at a medical center self-selected to participate in either a 3-month health coaching intervention or control group. The treatment group showed significant improvement in both SF-12 physical (p = .035) and mental (p = .0001) health status compared to controls. Because of concerns of selection bias, a matched case-control analysis was also performed, eliciting similar results. These findings suggest that MI-based health coaching is effective in improving both physical and mental health status in an occupational setting.

  18. Acid-base thermochemistry of gaseous aliphatic α-aminoacids.

    PubMed

    Bouchoux, Guy; Huang, Sihua; Inda, Bhawani Singh

    2011-01-14

    Acid-base thermochemistry of isolated aliphatic amino acids (denoted AAA): glycine, alanine, valine, leucine, isoleucine and proline has been examined theoretically by quantum chemical computations at the G3MP2B3 level. Conformational analysis on neutral, protonated and deprotonated species has been used to identify the lowest energy conformers and to estimate the population of conformers expected to be present at thermal equilibrium at 298 K. Comparison of the G3MP2B3 theoretical proton affinities, PA, and ΔH(acid) with experimental results is shown to be correct if experimental thermochemistry is re-evaluated and adapted to the most recent acidity-basicity scales. From this point of view, a set of evaluated proton affinities of 887, 902, 915, 916, 919 and 941 kJ mol(-1), and a set of evaluated ΔH(acid) of 1433, 1430, 1423, 1423, 1422 and 1426 kJ mol(-1), is proposed for glycine, alanine, valine, leucine, isoleucine and proline, respectively. Correlations with structural parameters (Taft's σ(α) polarizability parameter and molecular size) suggest that polarizability of the side chain is the major origin of the increase in PA and decrease in ΔH(acid) along the homologous series glycine, alanine, valine and leucine/isoleucine. Heats of formation of gaseous species AAA, AAAH(+) and [AAA-H](-) were computed at the G3MP2B3 level. The present study provides previously unavailable Δ(f)H°(298) for the ionized species AAAH(+) and [AAA-H](-). Comparison with Benson's estimate, and correlation with molecular size, show that several experimental Δ(f)H°(298) values of neutral or gaseous AAA might be erroneous.

  19. [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.

  20. 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.

  1. 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

  2. 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.

  3. "Are You an African?" The Politics of Self-Construction in Status-Based Social Movements.

    PubMed

    McCorkel, Jill; Rodriquez, Jason

    2009-05-01

    Current debates over identity politics hinge on the question of whether status-based social movements encourage parochialism and self-interest or create possibilities for mutual recognition across lines of difference. Our article explores this question through comparative, ethnographic study of two racially progressive social movements, "pro-black" abolitionism and "conscious" hip hop. We argue that status-based social movements not only enable collective identity, but also the personal identities or selves of their participants. Beliefs about the self create openings and obstacles to mutual recognition and progressive social action. Our analysis centers on the challenges that an influx of progressive, anti-racist whites posed to each movement. We examine first how each movement configured movement participation and racial identity and then how whites crafted strategic narratives of the self to account for their participation in a status-based movement they were not directly implicated in. We conclude with an analysis of the implications of these narratives for a critical politics of recognition. Keywords: identity politics, social movements, race, self, hip hop.

  4. 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.

  5. [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.

  6. 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.

  7. 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.

  8. The dual transcriptional regulator RovM regulates the expression of AR3- and T6SS4-dependent acid survival systems in response to nutritional status in Yersinia pseudotuberculosis.

    PubMed

    Song, Yunhong; Xiao, Xiao; Li, Changfu; Wang, Tietao; Zhao, Ruoxi; Zhang, Weipeng; Zhang, Lei; Wang, Yao; Shen, Xihui

    2015-11-01

    Coordinated regulation of various acid survival systems in response to environmental stimuli is crucial for the adaptation of enteropathogenic bacteria to acidic environments such as the stomach. In this study, we demonstrated that the RovM protein, a central regulator of the CsrABC-RovM-RovA cascade, conversely regulates the expression of two acid survival systems in Yersinia pseudotuberculosis by acting as a dual transcriptional regulator. RovM activated the expression of T6SS4, which is essential for bacterial survival under mild acidic conditions, by binding upstream of the T6SS4 promoter. On the contrary, RovM repressed the expression of a functional arginine-dependent acid resistance system (AR3), which is crucial for bacterial survival under strong acidic conditions, by directly binding to the -35 element in the AR3 promoter. Consistent with previous findings that rovM expression responds to the availability of nutrients, the expression of T6SS4 and AR3 was differentially regulated by nutritional status. Based on these results, a dynamic model whereby RovM coordinately regulates the expression of AR3 and T6SS4 in response to the availability of nutrients in the environment was proposed.

  9. Acid-base catalysis of N-[(morpholine)methylene]daunorubicin.

    PubMed

    Krause, Anna; Jelińska, Anna; Cielecka-Piontek, Judyta; Klawitter, Maria; Zalewski, Przemysław; Oszczapowicz, Irena; Wąsowska, Małgorzata

    2012-08-01

    The stability of N-[(morpholine)methylene]-daunorubicin hydrochloride (MMD) was investigated in the pH range 0.44-13.54, at 313, 308, 303 and 298 K. The degradation of MMD as a result of hydrolysis is a pseudo-first-order reaction described by the following equation: ln c = ln c(0) - k(obs)• t. In the solutions of hydrochloric acid, sodium hydroxide, borate, acetate and phosphate buffers, k(obs) = k(pH) because general acid-base catalysis was not observed. Specific acid-base catalysis of MMD comprises the following reactions: hydrolysis of the protonated molecules of MMD catalyzed by hydrogen ions (k(1)) and spontaneous hydrolysis of MMD molecules other than the protonated ones (k(2)) under the influence of water. The total rate of the reaction is equal to the sum of partial reactions: k(pH) = k(1) • a(H)+ • f(1) + k(2) • f(2) where: k(1) is the second-order rate constant (mol(-1) l s(-1)) of the specific hydrogen ion-catalyzed degradation of the protonated molecules of MMD; k(2) is the pseudo-first-order rate constant (s(-1)) of the water-catalyzed degradation of MMD molecules other than the protonated ones, f(1) - f(2) are fractions of the compound. MMD is the most stable at approx. pH 2.5.

  10. A microarray-based method to perform nucleic acid selections.

    PubMed

    Aminova, Olga; Disney, Matthew D

    2010-01-01

    This method describes a microarray-based platform to perform nucleic acid selections. Chemical ligands to which a nucleic acid binder is desired are immobilized onto an agarose microarray surface; the array is then incubated with an RNA library. Bound RNA library members are harvested directly from the array surface via gel excision at the position on the array where a ligand was immobilized. The RNA is then amplified via RT-PCR, cloned, and sequenced. This method has the following advantages over traditional resin-based Systematic Evolution of Ligands by Exponential Enrichment (SELEX): (1) multiple selections can be completed in parallel on a single microarray surface; (2) kinetic biases in the selections are mitigated since all RNA binders are harvested from an array via gel excision; (3) the amount of chemical ligand needed to perform a selection is minimized; (4) selections do not require expensive resins or equipment; and (5) the matrix used for selections is inexpensive and easy to prepare. Although this protocol was demonstrated for RNA selections, it should be applicable for any nucleic acid selection.

  11. Age estimation based on aspartic acid racemization in human sclera.

    PubMed

    Klumb, Karolin; Matzenauer, Christian; Reckert, Alexandra; Lehmann, Klaus; Ritz-Timme, Stefanie

    2016-01-01

    Age estimation based on racemization of aspartic acid residues (AAR) in permanent proteins has been established in forensic medicine for years. While dentine is the tissue of choice for this molecular method of age estimation, teeth are not always available which leads to the need to identify other suitable tissues. We examined the suitability of total tissue samples of human sclera for the estimation of age at death. Sixty-five samples of scleral tissue were analyzed. The samples were hydrolyzed and after derivatization, the extent of aspartic acid racemization was determined by gas chromatography. The degree of AAR increased with age. In samples from younger individuals, the correlation of age and D-aspartic acid content was closer than in samples from older individuals. The age-dependent racemization in total tissue samples proves that permanent or at least long-living proteins are present in scleral tissue. The correlation of AAR in human sclera and age at death is close enough to serve as basis for age estimation. However, the precision of age estimation by this method is lower than that of age estimation based on the analysis of dentine which is due to molecular inhomogeneities of total tissue samples of sclera. Nevertheless, the approach may serve as a valuable alternative or addition in exceptional cases.

  12. How Do Undergraduate Students Conceptualize Acid-Base Chemistry? Measurement of a Concept Progression

    ERIC Educational Resources Information Center

    Romine, William L.; Todd, Amber N.; Clark, Travis B.

    2016-01-01

    We developed and validated a new instrument, called "Measuring Concept progressions in Acid-Base chemistry" (MCAB) and used it to better understand the progression of undergraduate students' understandings about acid-base chemistry. Items were developed based on an existing learning progression for acid-base chemistry. We used the Rasch…

  13. 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

  14. Problem-Based Learning Research in Anesthesia Teaching: Current Status and Future Perspective

    PubMed Central

    Chilkoti, G.; Mohta, M.; Wadhwa, R.; Saxena, A. K.

    2014-01-01

    The teaching curriculum in anesthesia involves traditional teaching methods like topic-based didactic lectures, seminars, and journal clubs; intraoperative apprenticeship; and problem-based learning (PBL) and simulation. The advantages of incorporating PBL in anesthesia teaching include development of skills like clinical reasoning, critical thinking, and self-directed learning; in addition it also helps in developing a broader perspective of case scenarios. The present paper discusses the characteristics, key elements, and goals of PBL; various PBL methods available; lacunae in the existing knowledge of PBL research; its current status and future perspectives in anesthesia teaching. PMID:24982673

  15. Urea biosensors based on PVC membrane containing palmitic acid.

    PubMed

    Karakuş, Emine; Pekyardimci, Sule; Esma, Kiliç

    2005-01-01

    A new urea biosensor was prepared by immobilizing urease with four different procedures on poly(vinylchloride) (PVC) ammonium membrane electrode containing palmitic acid by using nonactine as an ammonium-ionophore. The analytical characteristics were investigated and were compared those of the biosensor prepared by using carboxylated PVC. The effect of pH, buffer concentration, temperature, urease concentration, stirring rate and enzyme immobilization procedures on the response to urea of the enzyme electrode were investigated. The linear working range and sensitivity of the biosensor were also determined. The urea biosensor prepared by using the PVC membranes containing palmitic acid showed more effective performance than those of the carboxylated PVC based biosensors. Additionally, urea assay in serum was successfully carried out by using the standard addition method.

  16. Reaction mechanisms of riboflavin triplet state with nucleic acid bases.

    PubMed

    Lin, Weizhen; Lu, Changyuan; Du, Fuqiang; Shao, Zhiyong; Han, Zhenhui; Tu, Tiecheng; Yao, Side; Lin, Nianyun

    2006-04-01

    ESR and laser flash photolysis studies have determined a reasonable order of reactivity of nucleotides with triplet riboflavin (3Rb*) for the first time. ESR detection of triplet state reactivity of Rb with nucleoside, polynucleotide and DNA has been obtained simultaneously. In addition, ESR spin elimination measurement of the reactivity of 3Rb* with nucleotides in good accord with laser flash photolysis determination of the corresponding rate constants offers a simple and reliable method to detect the reactivities of nucleic acids and its components with photoexcited flavins. Kinetic, ESR and thermodynamic studies have demonstrated that Rb should be a strong endogenous photosensitizer capable of oxidizing all nucleic acid bases, and preferentially two purine nucleotides with high rate constants.

  17. Major methodological constraints to the assessment of environmental status based on the condition of benthic communities

    NASA Astrophysics Data System (ADS)

    Medeiros, João Paulo; Pinto, Vanessa; Sá, Erica; Silva, Gilda; Azeda, Carla; Pereira, Tadeu; Quintella, Bernardo; Raposo de Almeida, Pedro; Lino Costa, José; José Costa, Maria; Chainho, Paula

    2014-05-01

    The Marine Strategy Framework Directive (MSFD) was published in 2008 and requires Member States to take the necessary measures to achieve or maintain good environmental status in aquatic ecosystems by the year of 2020. The MSFD indicates 11 qualitative descriptors for environmental status assessment, including seafloor integrity, using the condition of the benthic community as an assessment indicator. Member States will have to define monitoring programs for each of the MSFD descriptors based on those indicators in order to understand which areas are in a Good Environmental Status and what measures need to be implemented to improve the status of areas that fail to achieve that major objective. Coastal and offshore marine waters are not frequently monitored in Portugal and assessment tools have only been developed very recently with the implementation of the Water Framework Directive (WFD). The lack of historical data and knowledge on the constraints of benthic indicators in coastal areas requires the development of specific studies addressing this issue. The major objective of the current study was to develop and test and experimental design to assess impacts of offshore projects. The experimental design consisted on the seasonal and interannual assessment of benthic invertebrate communities in the area of future implementation of the structures (impact) and two potential control areas 2 km from the impact area. Seasonal benthic samples were collected at nine random locations within the impact and control areas in two consecutive years. Metrics included in the Portuguese benthic assessment tool (P-BAT) were calculated since this multimetric tool was proposed for the assessment of the ecological status in Portuguese coastal areas under the WFD. Results indicated a high taxonomic richness in this coastal area and no significant differences were found between impact and control areas, indicating the feasibility of establishing adequate control areas in marine

  18. 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

  19. [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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. [Effect of 3-oxypyridine and succinic acid derivatives on affective status in recrudescence of inflammatory diseases of uterus and its appendages].

    PubMed

    Volchegorskiĭ, I A; Pravdin, E V; Uzlova, T V

    2012-01-01

    Short-term, prospective placebo-controlled simple blind randomized study of the effects of 3-oxypyridine and succinic acid derivatives (emoxipin, reamberin, mexidol) on the affective status of females with recrudescence of the inflammatory diseases of uterus and its appendages (IDUA) in comparison to changes of systemic inflammatory response (SIR) markers level in the blood has been conducted. It is established that the inclusion of emoxipin, reamberin and mexidol in complex treatment of IDUA recrudescence reduce depression, anxiety and SIR laboratory signs. Mexidol being both 3-oxypyridine and succinic acid derivative showed the best influence on the dynamics of affective disorders and SIR changes.

  7. A vitamin B-12 supplement of 500 μg/d for eight weeks does not normalize urinary methylmalonic acid or other biomarkers of vitamin B-12 status in elderly people with moderately poor vitamin B-12 status.

    PubMed

    Hill, Marilyn H; Flatley, Janet E; Barker, Margo E; Garner, Clare M; Manning, Nigel J; Olpin, Simon E; Moat, Stuart J; Russell, Jean; Powers, Hilary J

    2013-02-01

    Plasma vitamin B-12 is the most commonly used biomarker of vitamin B-12 status, but the predictive value for low vitamin B-12 status is poor. The urinary methylmalonic acid (uMMA) concentration has potential as a functional biomarker of vitamin B-12 status, but the response to supplemental vitamin B-12 is uncertain. A study was conducted to investigate the responsiveness of uMMA to supplemental vitamin B-12 in comparison with other biomarkers of vitamin B-12 status [plasma vitamin B-12, serum holotranscobalamin (holoTC), plasma MMA] in elderly people with moderately poor vitamin B-12 status. A double-blind, placebo-controlled, randomized 8-wk intervention study was carried out using vitamin B-12 supplements (500 μg/d, 100 μg/d, and 10 μg/d cyanocobalamin) in 100 elderly people with a combined plasma vitamin B-12 <250 pmol/L and uMMA ratio (μmol MMA/mmol creatinine) >1.5. All biomarkers had a dose response to supplemental vitamin B-12. Improvements in plasma vitamin B-12 and serum holoTC were achieved at cobalamin supplements of 10 μg/d, but even 500 μg/d for 8 wk did not normalize plasma vitamin B-12 in 8% and serum holoTC in 12% of people. The response in uMMA was comparable with plasma MMA; 15-25% of people still showed evidence of metabolic deficiency after 500 μg/d cobalamin for 8 wk. There was a differential response in urinary and plasma MMA according to smoking behavior; the response was enhanced in ex-smokers compared with never-smokers. uMMA offers an alternative marker of metabolic vitamin-B12 status, obviating the need for blood sampling.

  8. Glia activation and cytokine increase in rat hippocampus by kainic acid-induced status epilepticus during postnatal development.

    PubMed

    Rizzi, Massimo; Perego, Carlo; Aliprandi, Marisa; Richichi, Cristina; Ravizza, Teresa; Colella, Daniele; Velískŏvá, Jana; Moshé, Solomon L; De Simoni, M Grazia; Vezzani, Annamaria

    2003-12-01

    In adult rats, status epilepticus (SE) induces cytokine production by glia especially when seizures are associated with neuronal injury. This suggests that cytokines may play a role in seizure-induced neuronal damage. As SE-induced injury is age-specific, we used rats of different ages (with distinct susceptibilities to seizure-induced neuronal injury) to elucidate the role of cytokines in this process. Thus, we investigated the activation of microglia and astrocytes, induction of cytokines, and hippocampal neuronal injury 4 and 24 h following kainic acid-induced SE in postnatal day (PN) 9, 15, and 21 rats. At PN9, there was little activation of microglia and astrocytes at any time point studied. Interleukin-1beta (IL), tumor necrosis factor-alpha (TNF), and IL-6 or the naturally occurring IL-1 receptor antagonist (Ra) mRNA expression did not increase. No evidence of cell injury has been detected. At PN15, immunostaining of microglia and astrocytes was enhanced, but only IL-1beta mRNA expression was increased. These changes were observed 4 h after SE. Scattered injured neurons in CA3 and subiculum, but not in any other region, were present 24 h following SE. At PN21, immunostaining of microglia and astrocytes and the mRNA expression of all cytokines studied was significantly increased already 4 h after SE. At 24 h, many injured neurons were present in CA1 and CA3 regions and in 40% of rats in other forebrain areas. These data show that (i) the pattern of glia activation and cytokine gene transcription induced by SE is age-dependent and (ii) neuronal injury in the hippocampus occurs only when cytokines are induced and their synthesis precedes the appearance of neuronal damage. Thus, cytokine expression in immature brain is associated specifically with cell injury rather than with seizures per se, suggesting that proinflammatory cytokines may contribute to the occurence of SE-induced hippocampal damage.

  9. Determination of the Acid-Base Dissociation Constant of Acid-Degradable Hexamethylenetetramine by Capillary Zone Electrophoresis.

    PubMed

    Takayanagi, Toshio; Shimakami, Natsumi; Kurashina, Masashi; Mizuguchi, Hitoshi; Yabutani, Tomoki

    2016-01-01

    The acid-base equilibrium of hexamethylenetetramine (hexamine) was analyzed with its effective electrophoretic mobility by capillary zone electrophoresis. Although hexamine is degradable in a weakly acidic aqueous solution, and the degraded products of ammonia and formaldehyde can be formed, the effective electrophoretic mobility of hexamine was measured in the pH range between 2.8 and 6.9. An acid-base dissociation equilibrium of the protonated hexamine was analyzed based on the mobility change, and an acid dissociation constant of pKa = 4.93 ± 0.01 (mean ± standard error, ionic strength: 0.020 mol dm(-3)) was determined. The monoprotic acid-base equilibrium of hexamine was confirmed through comparisons of its electrophoretic mobility with the N-ethylquinolinium ion and with the monocationic N-ethyl derivative of hexamine, as well as a slope analysis of the dissociation equilibrium.

  10. 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

  11. 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.

  12. Maternal multiple micronutrient supplementation has limited impact on micronutrient status of Bangladeshi infants compared with standard iron and folic acid supplementation.

    PubMed

    Eneroth, Hanna; El Arifeen, Shams; Persson, Lars-Ake; Lönnerdal, Bo; Hossain, Mohammad Bakhtiar; Stephensen, Charles B; Ekström, Eva-Charlotte

    2010-03-01

    Knowledge about the impact of maternal food and micronutrient supplementation on infant micronutrient status is limited. We examined the effect of maternal food and micronutrient supplementation on infant micronutrient status in the Maternal and Infant Nutrition Interventions in Matlab Trial. Pregnant women (n = 4436) were randomized to Early or Usual promotion of enrollment in a food supplementation program. In addition, they were randomly allocated to 1 of the following 3 types of daily micronutrient supplements provided from wk 14 of gestation to 3 mo postpartum: 1) folic acid and 30 mg iron (Fe30Fol); 2) folic acid and 60 mg iron; or 3) a multiple micronutrient including folic acid and 30 mg iron (MMS). At 6 mo, infant blood samples (n = 1066) were collected and analyzed for hemoglobin and plasma ferritin, zinc, retinol, vitamin B-12, and folate. The vitamin B-12 concentration differed between the micronutrient supplementation groups (P = 0.049). The prevalence of vitamin B-12 deficiency was lower in the MMS group (26.1%) than in the Fe30Fol group (36.5%) (P = 0.003). The prevalence of zinc deficiency was lower in the Usual food supplementation group (54.1%) than in the Early group (60.2%) (P = 0.046). There were no other differential effects according to food or micronutrient supplementation groups. We conclude that maternal multiple micronutrient supplementation may have a beneficial effect on vitamin B-12 status in infancy.

  13. A fully automatic system for acid-base coulometric titrations

    PubMed Central

    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. PMID:18925283

  14. Impact of gender-based career obstacles on the working status of women physicians in Japan.

    PubMed

    Nomura, Kyoko; Gohchi, Kengo

    2012-11-01

    Research has shown that women physicians work fewer hours and are more likely to become inactive professionally and to switch to part-time labor, compared with their male counterparts. The published literature suggests that a gender disparity still exists in medicine which may decrease work motivation among women physicians. The authors investigated whether the experience and the perception of gender-based career obstacles among women physicians in Japan are associated with their working status (i.e., full-time vs. part-time). The present cross-sectional study is based on surveys of alumnae from 13 private medical schools in Japan conducted between June 2009 and May 2011. Of those who agreed to participate in this study, 1684 completed a self-administered questionnaire (overall response rate 83%). Experience of gender-based obstacles was considered affirmative if a woman physician had been overlooked for opportunities of professional advancement based on gender. Perception of gender-based obstacles referred to the self-reported degree of difficulty of promotion and opportunities for a position in higher education. Approximately 20% of the study participants responded that they experienced gender-based obstacles while 24% answered that they were not sure. The scores for perception of gender-based career obstacles were statistically higher among part-time workers compared with full-time workers (mean difference = 1.20, 95% CI: 0.39-2.00). Adjusting for age, marital status, the presence of children, workplace, board certification, holding a PhD degree, overall satisfaction of being a physician, and household income, stepwise logistic regression models revealed that physicians with the strongest perception of gender-based career obstacles were more likely to work part-time rather than full-time (OR, 0.59; 95% CI: 0.40-0.88). Although the experience of gender-based obstacles was not associated with working status among women physicians, the results demonstrated that a

  15. [Choice of plant light status for space greenhouse: results of ground-based experience].

    PubMed

    Berkovich, Iu A

    2000-01-01

    To decide on the light status of plants in space greenhouse, a theoretical study was undertaken to correlate specific productivity of space greenhouse with illumination characteristics including vertical PAR flux density (I), photoperiod (tau), and crop leaf index (L). It was demonstrated that in pace with I the daily productivity per a volume unit tended to monotonously approach maximum at I = Ip, whereas the greenhouse energy efficiency ME peaked at I = IE, IK < IE < IP, where IK is a compensation point of the light curve of crop photosynthesis. Proposed are compromise criteria to optimize illumination as a maximum of linear combination of MV and ME and coefficients which account for the cost of a space station volume unit and a unit of board power supply, and as maximum of product Q = MV.ME. Experimental results serve as the basis for a technique for determination of the best, by the Q criterion, light status parameters for three types of space greenhouses: research growth chamber for synchronous cultivation of leaf mustard, wheat growth chamber with fixed crop density, and green conveyer for cultivation of Brassica pekinensis (Lour Rupor). For the last mentioned Q effective I and tau values differed with the conveyer step. The technique allows design of ground-based experiments aimed at determination of the most effective light status of space-grown crops.

  16. Predicting the Viscosity of Low VOC Vinyl Ester and Fatty Acid-Based Resins

    DTIC Science & Technology

    2005-12-01

    The sample was titrated with the perchloric acid / peracetic acid solution (Aldrich) until the indicator, 0.1% crystal violet in acetic acid (Aldrich...Predicting the Viscosity of Low VOC Vinyl Ester and Fatty Acid -Based Resins by John J. La Scala, Amutha Jeyarajasingam, Cherise Winston...Aberdeen Proving Ground, MD 21005-5069 ARL-TR-3681 December 2005 Predicting the Viscosity of Low VOC Vinyl Ester and Fatty Acid -Based

  17. 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.

  18. [Oxidative stress in blood leukocytes, pro/antioxidant status and fatty acids composition of pancreas lipids at experimental acute pancreatitis in rats].

    PubMed

    Pryvrots'ka, I B; Kuchmerovs'ka, T M

    2013-01-01

    In an experimental model of acute pancreatitis (AP) in rats no alteration in leukocyte's viability was found by flow cytometry as compared to control. After 1 day of AP production of reactive oxygen forms in granulocytes was increased more than 5 times, but after 3 days their level was decreased. Alterations of pro/antioxidant status and specific changes in the fatty acid composition in the pancreas were established. With the development of AP, the processes of lipids peroxidation were intensified while antioxidant system was altered, that was evidenced by inflammation in the pancreas. In these conditions, the increase of phospholipase A2 activity was accompanied by significant changes of fatty acid composition of the total lipids in the pancreas. This increased relative total content of saturated fatty acids, in particular myristic, palmitic and stearic acid increased, while the total content of polyunsaturated essential fatty acids omega-3 (linolenic, eicosapentaenoic, dokozapentayenoic, docosahexaenoic) decreased. The preparation containing omega-3 polyunsaturated fatty acids partially normalized the lipid and fatty acids composition as well as prooxidant-antioxidant system.

  19. 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.

  20. New insights into glioma classification based on isocitrate dehydrogenase 1 and 2 gene status.

    PubMed

    Shibahara, Ichiyo; Sonoda, Yukihiko; Kanamori, Masayuki; Saito, Ryuta; Kumabe, Toshihiro; Tominaga, Teiji

    2011-07-01

    In glioma, mutations in the isocitrate dehydrogenase 1 and 2 (IDH1/2) genes have been receiving attention. IDH1/2 mutations are frequently found in grade II and III gliomas. These genetic alterations occur very early in gliomagenesis and strongly predict favorable outcome in patients with high-grade gliomas. Despite the evolution of studies on this topic, the underlying mechanism of the IDH1/2 mutations remains unknown. Here, we briefly review the current knowledge of IDH1/2 and discuss molecular diagnostics based on IDH1/2 gene status.

  1. 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

  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

    SciTech Connect

    Wu, Peiwen; Yu, Yang; McGhee, Claire E.; Tan, Li Huey; Lu, Yi

    2014-09-10

    In this paper, 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.

  4. Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

    DOE PAGES

    Wu, Peiwen; Yu, Yang; McGhee, Claire E.; ...

    2014-09-10

    In this paper, 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. Insightsmore » gained from these studies are described and future directions of this field are also discussed.« less

  5. The effects of borate minerals on the synthesis of nucleic acid bases, amino acids and biogenic carboxylic acids from formamide.

    PubMed

    Saladino, Raffaele; Barontini, Maurizio; Cossetti, Cristina; Di Mauro, Ernesto; Crestini, Claudia

    2011-08-01

    The thermal condensation of formamide in the presence of mineral borates is reported. The products afforded are precursors of nucleic acids, amino acids derivatives and carboxylic acids. The efficiency and the selectivity of the reaction was studied in relation to the elemental composition of the 18 minerals analyzed. The possibility of synthesizing at the same time building blocks of both genetic and metabolic apparatuses, along with the production of amino acids, highlights the interest of the formamide/borate system in prebiotic chemistry.

  6. 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.

  7. 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.

  8. Current Status of the Ceph Based Storage Systems at the RACF

    NASA Astrophysics Data System (ADS)

    Zaytsev, A.; Ito, H.; Hollowell, C.; Wong, T.; Rao, T.

    2015-12-01

    Ceph based storage solutions are becoming increasingly popular within the HEP/NP community over the last few years. With the current status of Ceph project, both object storage and block storage (RBD) layers are production ready on a large scale, and the Ceph file system storage layer (CephFS) is rapidly getting to that state as well. This contribution contains a thorough review of various functionality, performance and stability tests performed with all three (object storage, block storage and file system) levels of Ceph by using the RACF computing resources in 2012-2014 on various hardware platforms and with different networking solutions (10/40 GbE and IPoIB/4X FDR Infiniband based). We also report the status of commissioning a large scale (1 PB of usable capacity, 4k HDDs behind the RAID arrays by design) Ceph based object storage system provided with Amazon S3 complaint RadosGW interfaces deployed in RACF, as well as performance results obtained while testing the RBD and CephFS storage layers of our Ceph clusters.

  9. 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.

  10. 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.

  11. 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.

  12. Microarray-based transcriptome of Listeria monocytogenes adapted to sublethal concentrations of acetic acid, lactic acid, and hydrochloric acid.

    PubMed

    Tessema, Girum Tadesse; Møretrø, Trond; Snipen, Lars; Heir, Even; Holck, Askild; Naterstad, Kristine; Axelsson, Lars

    2012-09-01

    Listeria monocytogenes , an important foodborne pathogen, commonly encounters organic acids in food-related environments. The transcriptome of L. monocytogenes L502 was analyzed after adaptation to pH 5 in the presence of acetic acid, lactic acid, or hydrochloric acid (HCl) at 25 °C, representing a condition encountered in mildly acidic ready-to-eat food kept at room temperature. The acid-treated cells were compared with a reference culture with a pH of 6.7 at the time of RNA harvesting. The number of genes and magnitude of transcriptional responses were higher for the organic acids than for HCl. Protein coding genes described for low pH stress, energy transport and metabolism, virulence determinates, and acid tolerance response were commonly regulated in the 3 acid-stressed cultures. Interestingly, the transcriptional levels of histidine and cell wall biosynthetic operons were upregulated, indicating possible universal response against low pH stress in L. monocytogenes. The opuCABCD operon, coding proteins for compatible solutes transport, and the transcriptional regulator sigL were significantly induced in the organic acids, strongly suggesting key roles during organic acid stress. The present study revealed the complex transcriptional responses of L. monocytogenes towards food-related acidulants and opens the roadmap for more specific and in-depth future studies.

  13. High resolution melt curve analysis based on methylation status for human semen identification.

    PubMed

    Fachet, Caitlyn; Quarino, Lawrence; Karnas, K Joy

    2017-03-01

    A high resolution melt curve assay to differentiate semen from blood, saliva, urine, and vaginal fluid based on methylation status at the Dapper Isoform 1 (DACT1) gene was developed. Stains made from blood, saliva, urine, semen, and vaginal fluid were obtained from volunteers and DNA was isolated using either organic extraction (saliva, urine, and vaginal fluid) or Chelex(®) 100 extraction (blood and semen). Extracts were then subjected to bisulfite modification in order to convert unmethylated cytosines to uracil, consequently creating sequences whose amplicons have melt curves that vary depending on their initial methylation status. When primers designed to amplify the promoter region of the DACT1 gene were used, DNA from semen samples was distinguishable from other fluids by a having a statistically significant lower melting temperature. The assay was found to be sperm-significant since semen from a vasectomized man produced a melting temperature similar to the non-semen body fluids. Blood and semen stains stored up to 5 months and tested at various intervals showed little variation in melt temperature indicating the methylation status was stable during the course of the study. The assay is a more viable method for forensic science practice than most molecular-based methods for body fluid stain identification since it is time efficient and utilizes instrumentation common to forensic biology laboratories. In addition, the assay is advantageous over traditional presumptive chemical methods for body fluid identification since results are confirmatory and the assay offers the possibility of multiplexing which may test for multiple body fluids simultaneously.

  14. 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

  15. [Microspeciation of amphoteric molecules of unusual acid-base properties].

    PubMed

    Kóczián, Kristóf

    2007-01-01

    The phisico-chemical properties of bio- and drug molecules greatly influence their interactions in the body and strongly effect the mechanism of drug action. Among these properties, macroscopic and site-specific protonation constants are of crucial importance. Latter one is the tool to calculate the relative concentration of the various microspecies in the compartments of the body at different pH values, and also, it is the versatile parameter to improve the pharmacokinetic properties of a new molecule in a particular family of drugs. In the present thesis work, the microspeciation of three molecules of great pharmaceutical importance and unusual acid-base properties, were carried out. The microconstants of tenoxicam, the non-steroidal anti-inflammatory drug, were described, introducing a novel deductive method using Hammett constants. For this purpose, a total of 8 tenoxicam and piroxicam derivatives were synthesised. To the best of our knowledge, the log k(N)O microconstant of tenoxicam obtained thus is the lowest enolate basicity value, which, however, can be well explained by the effects of the intramolecular environment. The developed evaluation procedure is suitable for microconstant determination of compounds in other molecule families. Besides, prodrug-type compounds and analogues similar to the structures of selective COX-2 isoenzyme inhibitors were synthesised. The other two molecules studied, the 6-aminopenicillanic acid and 7-cephalosporanic acid, the core molecules of the two most important beta-lactam antibiotic-types were derivatised and investigated by 1D and 2D NMR techniques. The NMR-pH titration on the parent compounds and their ester derivatives, combined with in situ pH-measurements allowed the microspeciation of these easily decomposing molecules. One of the protonation constant of 7-ACA (log kN(O) = 4.12), to the best of our knowledge, is the least non-aromatic basic amino-site among the natural compounds.

  16. 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.

  17. 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.

  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. 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.

  20. Folate and vitamin B-12 status in relation to anemia, macrocytosis, and cognitive impairment in older Americans in the age of folic acid fortification1234

    PubMed Central

    Morris, Martha Savaria; Jacques, Paul F; Rosenberg, Irwin H; Selhub, Jacob

    2007-01-01

    Background Historic reports on the treatment of pernicious anemia with folic acid suggest that high-level folic acid fortification delays the diagnosis of or exacerbates the effects of vitamin B-12 deficiency, which affects many seniors. This idea is controversial, however, because observational data are few and inconclusive. Furthermore, experimental investigation is unethical. Objective We examined the relations between serum folate and vitamin B-12 status relative to anemia, macrocytosis, and cognitive impairment (ie, Digit Symbol-Coding score <34) in senior participants in the 1999–2002 US National Health and Nutrition Examination Survey. Design The subjects had normal serum creatinine concentrations and reported no history of stroke, alcoholism, recent anemia therapy, or diseases of the liver, thyroid, or coronary arteries (n = 1459). We defined low vitamin B-12 status as a serum vitamin B-12 concentration <148 pmol/L or a serum methylmalonic acid concentration >210 nmol/L—the maximum of the reference range for serum vitamin B-12–replete participants with normal creatinine. Results After control for demographic characteristics, cancer, smoking, alcohol intake, serum ferritin, and serum creatinine, low versus normal vitamin B-12 status was associated with anemia [odds ratio (OR): 2.7; 95% CI: 1.7, 4.2], macrocytosis (OR: 1.8; 95% CI: 1.01, 3.3), and cognitive impairment (OR: 2.5; 95% CI: 1.6, 3.8). In the group with a low vitamin B-12 status, serum folate ≤59 nmol/L (80th percentile), as opposed to ≤59 nmol/L, was associated with anemia (OR: 3.1; 95% CI: 1.5, 6.6) and cognitive impairment (OR: 2.6; 95% CI: 1.1, 6.1). In the normal vitamin B-12 group, ORs relating high versus normal serum folate to these outcomes were <1.0 (Pinteraction <0.05), but significantly <1.0 only for cognitive impairment (0.4; 95% CI: 0.2, 0.9). Conclusion In seniors with low vitamin B-12 status, high serum folate was associated with anemia and cognitive impairment. When

  1. 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.

  2. 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.

  3. Regional Monitoring of Acidic Lakes and Streams

    EPA Pesticide Factsheets

    This asset provides data on the acid-base status of lakes and streams. Key chemical indicators measured include: sulfate, nitrate, ammonium, chloride, Acid Neutralizing Capacity (ANC), pH, base cations, dissolved organic carbon (DOC), total aluminum. TIME and LTM are part of EPA's Environmental Monitoring and Assessment Program (EMAP). Long-term monitoring of the acid-base status (pH, ANC, SO4, NO3, NH4, DOC, base cations, Al) in lakes and streams. Monitoring is conducted in acid sensitive regions of the Eastern U.S.

  4. 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…

  5. 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

  6. Family-based training program improves brain function, cognition, and behavior in lower socioeconomic status preschoolers

    PubMed Central

    Neville, Helen J.; Stevens, Courtney; Pakulak, Eric; Bell, Theodore A.; Fanning, Jessica; Klein, Scott; Isbell, Elif

    2013-01-01

    Using information from research on the neuroplasticity of selective attention and on the central role of successful parenting in child development, we developed and rigorously assessed a family-based training program designed to improve brain systems for selective attention in preschool children. One hundred forty-one lower socioeconomic status preschoolers enrolled in a Head Start program were randomly assigned to the training program, Head Start alone, or an active control group. Electrophysiological measures of children’s brain functions supporting selective attention, standardized measures of cognition, and parent-reported child behaviors all favored children in the treatment program relative to both control groups. Positive changes were also observed in the parents themselves. Effect sizes ranged from one-quarter to half of a standard deviation. These results lend impetus to the further development and broader implementation of evidence-based education programs that target at-risk families. PMID:23818591

  7. [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.

  8. 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.

  9. Haematological, blood gas and acid-base effects of central histamine-induced reversal of critical haemorrhagic hypotension in rats.

    PubMed

    Jochem, J

    2001-09-01

    In a rat model of volume-controlled irreversible haemorrhagic shock, which results in a severe metabolic acidosis and the death of all control animals within 30 min., intracerebroventricular injection of histamine (100 nmol) produces a prompt and long-lasting increase in mean arterial pressure and heart rate, with a 100% survival of 2 h after treatment. Histamine action is accompanied by a decrease in haematocrit value, haemoglobin concentration, erythrocyte and platelet count, and an increase in residual blood volume at the end of the experiment (2 h). Cardiovascular effects are also associated with a long-lasting rise in respiratory rate and biphasic blood acid-base changes - initial increase of metabolic acidosis with the decrease in arterial and venous pH, bicarbonate concentration and base excess, followed by almost a complete recovery of blood gas and acid-base parameters to the pre-bleeding values, with normalisation of arterial and venous pH, Pco2 bicarbonate concentration and base excess at the end of experiment. It can be concluded that in the late phase of central histamine-induced reversal of haemorrhagic hypotension there is almost a complete restoration of blood gas and acid-base status due to circulatory and respiratory compensations, while accompanying haematological changes are the result of the haemodilution and the increase in residual blood volume.

  10. Drug delivery systems based on nucleic acid nanostructures.

    PubMed

    de Vries, Jan Willem; Zhang, Feng; Herrmann, Andreas

    2013-12-10

    The field of DNA nanotechnology has progressed rapidly in recent years and hence a large variety of 1D-, 2D- and 3D DNA nanostructures with various sizes, geometries and shapes is readily accessible. DNA-based nanoobjects are fabricated by straight forward design and self-assembly processes allowing the exact positioning of functional moieties and the integration of other materials. At the same time some of these nanosystems are characterized by a low toxicity profile. As a consequence, the use of these architectures in a biomedical context has been explored. In this review the progress and possibilities of pristine nucleic acid nanostructures and DNA hybrid materials for drug delivery will be discussed. For the latter class of structures, a distinction is made between carriers with an inorganic core composed of gold or silica and amphiphilic DNA block copolymers that exhibit a soft hydrophobic interior.

  11. The Significance of Acid/Base Properties in Drug Discovery

    PubMed Central

    Manallack, David T.; Prankerd, Richard J.; Yuriev, Elizabeth; Oprea, Tudor I.; Chalmers, David K.

    2013-01-01

    While drug discovery scientists take heed of various guidelines concerning drug-like character, the influence of acid/base properties often remains under-scrutinised. Ionisation constants (pKa values) are fundamental to the variability of the biopharmaceutical characteristics of drugs and to underlying parameters such as logD and solubility. pKa values affect physicochemical properties such as aqueous solubility, which in turn influences drug formulation approaches. More importantly, absorption, distribution, metabolism, excretion and toxicity (ADMET) are profoundly affected by the charge state of compounds under varying pH conditions. Consideration of pKa values in conjunction with other molecular properties is of great significance and has the potential to be used to further improve the efficiency of drug discovery. Given the recent low annual output of new drugs from pharmaceutical companies, this review will provide a timely reminder of an important molecular property that influences clinical success. PMID:23099561

  12. Nucleic Acid-Based Therapy Approaches for Huntington's Disease

    PubMed Central

    Vagner, Tatyana; Young, Deborah; Mouravlev, Alexandre

    2012-01-01

    Huntington's disease (HD) is caused by a dominant mutation that results in an unstable expansion of a CAG repeat in the huntingtin gene leading to a toxic gain of function in huntingtin protein which causes massive neurodegeneration mainly in the striatum and clinical symptoms associated with the disease. Since the mutation has multiple effects in the cell and the precise mechanism of the disease remains to be elucidated, gene therapy approaches have been developed that intervene in different aspects of the condition. These approaches include increasing expression of growth factors, decreasing levels of mutant huntingtin, and restoring cell metabolism and transcriptional balance. The aim of this paper is to outline the nucleic acid-based therapeutic strategies that have been tested to date. PMID:22288011

  13. 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.).

  14. Agreement in measuring socio-economic status: area-based versus individual measures.

    PubMed

    Demissie, K; Hanley, J A; Menzies, D; Joseph, L; Ernst, P

    2000-01-01

    Area-based socio-economic status (SES) measures are frequently used in epidemiology. Such an approach assumes socio-economic homogeneity within an area. To quantify the agreement between area-based SES measures and SES assessed at the individual level, we conducted a cross-sectional study of 943 children who resided in 155 small enumeration areas and 117 census tracts from 18 schools in Montreal, Quebec. We used street address information together with 1986 census data and parental occupation to establish area-based and individual level SES indicators, respectively. As compared with the SES score determined at the level of the individual, 13 different area-based SES indices classified the children within the same quintile 28.7% (+/- 2.8%) of the time. The discrepancy was within one quintile in 35.3% (+/- 2.3%) of cases, two quintiles in 20.6% (+/- 3.6%), three quintiles in 11.3% (+/- 4.2%) and four quintiles in 4.1% (+/- 0.2%). In conclusion, we observed a substantial discrepancy between area- based SES measures and SES assessed at the individual level. Caution should therefore be used in designing or interpreting the results of studies in which area-based SES measures are used to test hypotheses or control for confounding.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. Lipid content and essential fatty acid (EFA) composition of mature Congolese breast milk are influenced by mothers' nutritional status: impact on infants' EFA supply.

    PubMed

    Rocquelin, G; Tapsoba, S; Dop, M C; Mbemba, F; Traissac, P; Martin-Prével, Y

    1998-03-01

    Optimum infant growth and development, especially neurodevelopment and visual acuity, require sufficient n-6 and n-3 essential fatty acid supplies from the placenta or breast milk. The lipid content and fatty acid composition of mature breast milk were measured in samples from 102 randomly selected Congolese mothers of 5-month-old infants, residing in a suburban district of Brazzaville. Mean body mass index (BMI) was 22.3; 14% of mothers were energy-deficient and 22% were overweight. Breast milk samples from these mothers were low in lipids (mean, 28.70 g/l), and 75% had a lipid content below reference values. Adequate lipid content was associated with a maternal diet high in carbohydrates and low in fats. Breast milk was rich in 8:0-14:0 fatty acids (25.97% of total fatty acids) and in polyunsaturated fatty acids, especially n-3. These findings appear related to Congolese mothers' frequent consumption of high-carbohydrate foods such as processed cassava roots, wheat bread, and doughnuts known to enhance 8:0-14:0 fatty acid biosynthesis, as well as locally produced foods such as fish, vegetable oil, leafy green vegetables, and high-fat fruit that provide n-6 and n-3 essential fatty acids. Milk lipid content was inversely associated with the maternal BMI, but was unrelated to maternal age or socioeconomic status. Since the essential fatty acid content of traditional complementary foods is lower than that present in breast milk, Congolese mothers should be encouraged to postpone the introduction of such foods until their infant is 4-6 months old.

  20. Glucomannan- and glucomannan plus spirulina-enriched pork affect liver fatty acid profile, LDL receptor expression and antioxidant status in Zucker fa/fa rats fed atherogenic diets

    PubMed Central

    González-Torres, Laura; Matos, Cátia; Vázquez-Velasco, Miguel; Santos-López, Jorge A.; Sánchez-Martínez, Iria; García–Fernández, Camino; Bastida, Sara; Benedí, Juana; Sánchez-Muniz, Francisco J.

    2017-01-01

    ABSTRACT We evaluated the effects of glucomannan or glucomannan plus spirulina-restructured pork (RP) on liver fatty acid profile, desaturase/elongase enzyme activities and oxidative status of Zucker fa/fa rats for seven weeks. Control (C), glucomannan (G) and glucomannan/spirulina (GS)-RP; HC (cholesterol-enriched control), HG and HGS (cholesterol-enriched glucomannan and glucomannan/spirulina-RP) experimental diets were tested. Increased metabolic syndrome markers were found in C, G and GS rats. Cholesterol feeding increased liver size, fat, and cholesterol and reduced antioxidant enzyme levels and expressions. Cholesterolemia was lower in HG and HGS than in HC. GS vs. G showed higher stearic but lower oleic levels. SFA and PUFA decreased while MUFA increased by cholesterol feeding. The arachidonic/linoleic and docosahexaenoic/alpha-linolenic ratios were lower in HC, HG, and HGS vs. C, G, and GS, respectively, suggesting a delta-6-elongase-desaturase system inhibition. Moreover, cholesterol feeding, mainly in HGS, decreased low-density-lipoprotein receptor expression and the delta-5-desaturase activity and increased the delta-9-desaturase activity. In conclusion, the liver production of highly unsaturated fatty acids was limited to decrease their oxidation in presence of hypercholesterolaemia. Glucomannan or glucomannan/spirulina-RP has added new attributes to their functional properties in meat, partially arresting the negative effects induced by high-fat-high-cholesterol feeding on the liver fatty acid and antioxidant statuses. PMID:28325998

  1. 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.

  2. Community mobilization and social marketing to promote weekly iron-folic acid supplementation in women of reproductive age in Vietnam: impact on anemia and iron status.

    PubMed

    Berger, Jacques; Thanh, Hoang Thi Kim; Cavalli-Sforza, Tommaso; Smitasiri, Suttilak; Khan, Nguyen Cong; Milani, Silvano; Hoa, Pham Thuy; Quang, Nguyen Dinh; Viteri, Fernando

    2005-12-01

    The community mobilization and social marketing program promoting a preventive approach of weekly iron-folic acid supplementation in women of reproductive age improved iron status of non-pregnant women in Vietnam. Three to six months of weekly pre-pregnancy supplementation and regular weekly intake of supplements during pregnancy allowed women to achieve good iron and hemoglobin status during the two first trimesters of pregnancy. In the third trimester, iron deficiency and anemia were notably present but low birth weight prevalence was low. This demonstrates the effectiveness and safety of the preventive approach as implemented here to prevent and control iron deficiency and anemia in women of reproductive age before and during pregnancy.

  3. 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.

  4. Brain docosahexaenoic acid status and learning in young rats submitted to dietary long-chain polyunsaturated fatty acid deficiency and supplementation limited to lactation.

    PubMed

    García-Calatayud, Salvador; Redondo, Carlos; Martín, Eva; Ruiz, José Ignacio; García-Fuentes, Miguel; Sanjurjo, Pablo

    2005-05-01

    N-3 fatty acid deficiency has been related to decreased docosahexaenoic acid (DHA) and increased docosapentaenoic acid (DPA) levels in brain and to learning disadvantages. The influence of n-3 deficiency and supplementation on brain fatty acids and learning were investigated in young rats. Newborn Wistar rats were assigned to three groups of cross-foster mothers. The control group (C) was nursed by mothers that received essential fatty acids during pregnancy and lactation, and the deficient group (D) was nursed by mothers that did not receive those fatty acids. The supplemental group (S) had the same conditions as D, receiving an additional DHA and arachidonic acid supplement during lactation. Cerebral cortex and hippocampus fatty acid composition was examined using thin-layer and capillary column gas chromatography, and learning was measured by passive-avoidance procedure. D brains showed low DHA and high DPA levels, but S brain composition was similar to C. Learning in the S group was unaffected, but in the D group, it was poorer than C. Learning was directly correlated with DHA levels and inversely with DPA levels in brain. Low DHA and high DPA brain levels both were correlated with poor learning. DPA seems not to be a suitable brain functional analogue of DHA, and DHA supplementation reversed both biochemical and learning adverse effects observed in n-3 deficiency.

  5. 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.

  6. 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.

  7. Science review: quantitative acid-base physiology using the Stewart model.

    PubMed

    Wooten, E Wrenn

    2004-12-01

    There has been renewed interest in quantifying acid-base disorders in the intensive care unit. One of the methods that has become increasingly used to calculate acid-base balance is the Stewart model. This model is briefly discussed in terms of its origin, its relationship to other methods such as the base excess approach, and the information it provides for the assessment and treatment of acid-base disorders in critically ill patients.

  8. Vitamin K status in spaceflight and ground-based models of spaceflight.

    PubMed

    Zwart, Sara R; Booth, Sarah L; Peterson, James W; Wang, Zuwei; Smith, Scott M

    2011-05-01

    Bone loss is a well-documented change during and after long-duration spaceflight. Many types of countermeasures to bone loss have been proposed, including vitamin K supplementation. The objective of this series of studies was to measure change in vitamin K status in response to microgravity under a variety of spaceflight and spaceflight analog (model) conditions, including long-duration spaceflight studies (n = 15), three bed rest studies (n = 15, 49, and 24), and a 14-day saturation dive (n = 6). In crew members who flew 2-6 months on the International Space Station, in-flight and postflight plasma phylloquinone concentrations were unchanged from the preflight mean. Consistent with this finding, urinary γ-carboxyglutamic acid (GLA), a measure of vitamin K-dependent protein turnover, did not change in response to flight. Serum undercarboxylated osteocalcin (%ucOC), a measure of vitamin K function, was generally unchanged in response to flight. Spaceflight findings were corroborated by findings of no changes in phylloquinone, urinary GLA, or %ucOC during or after bed rest in three separate bed rest studies (21-90 days in duration) or after a 14-day saturation dive. The data presented here do not support either a need for vitamin K supplementation during spaceflight or the suggestion of using vitamin K as a bone loss countermeasure in spaceflight.

  9. 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.

  10. 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...

  11. Impaired oxidant/antioxidant status and LDL-fatty acid composition are associated with increased susceptibility to peroxidation of LDL in diabetic patients.

    PubMed

    Merzouk, S; Hichami, A; Sari, A; Madani, S; Merzouk, H; Yahia Berrouiguet, A; Lenoir-Rousseaux, J J; Chabane-Sari, N; Khan, N A

    2004-12-01

    This study was carried out to determine the relationships between oxidant/antioxidant status, in vitro LDL oxidizability and LDL-fatty acid composition in diabetes mellitus. Plasma total antioxidant capacity (oxygen radical absorbance capacity, ORAC) and LDL-cholesteryl ester fatty acids were investigated in type 1 and type 2 diabetic subjects with and without complications. The degree of LDL oxidation was determined by the measurement of hydroperoxide levels before and after in vitro peroxidative stress with CuSO4. ORAC values were decreased in diabetic subjects who showed high basal hydroperoxide levels. Oxidizability of LDL in these subjects was higher than in control subjects and it was unrelated to LDL-fatty acid composition. However, in type 2 diabetic subjects with complications, alterations in LDL-fatty acid composition were associated with their enhanced oxidative susceptibility. LDL-fatty acid alterations might be an additional factor that influences LDL oxidizability especially in type 2 diabetes. In conclusion, diabetes mellitus is associated with enhanced oxidative stress and defective antioxidant/oxidant balance regardless the type of diabetes and presence of complications.

  12. Effect of microbial inoculation during vermicomposting of different organic substrates on microbial status and quantification and documentation of acid phosphatase.

    PubMed

    Pramanik, P; Ghosh, G K; Banik, P

    2009-02-01

    In this experiment, three microbial strains were inoculated in two different organic wastes to study their effect on the humic acids content, acid phosphatase activity and microbial properties of the final stabilized products. Pyrophosphate extract of vermicomposts were analyzed through polyacrylamide gel electrophoresis to study the nature of a isozymes in different treatments. Results suggested that vermicomposting increased humic acids content and acid phosphatase activity in organic substrates and microbial inoculation further enhanced the rate of humification and enzyme activity. Although humic acids content in different microorganism-inoculated vermicomposts were statistically at par, acid phosphatase activity in these treatments was significantly (P<0.05) different. Results revealed that microbial respiration was increased due to vermicomposting, but a reduction in microbial biomass was recorded after stabilization of organic wastes. Although vermicomposting increased the value of microbial quotient (qCO(2)), microbial inoculation did not show any significant effect on qCO(2). The zymogram revealed that two isozymes of acid phosphatase (group II and group III) were present in all vermicompost samples and higher acid phosphatase activity in fungi-inoculated vermicomposts might be due to the presence of an additional isozyme (group I) of acid phosphatase.

  13. Guanine base stacking in G-quadruplex nucleic acids

    PubMed Central

    Lech, Christopher Jacques; Heddi, Brahim; Phan, Anh Tuân

    2013-01-01

    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

  14. Thermochemical study of the reactions of acid-base interaction in an aqueous solution of α-aminobutyric acid

    NASA Astrophysics Data System (ADS)

    Lytkin, A. I.; Chernikov, V. V.; Krutova, O. N.; Skvortsov, I. A.; Korchagina, A. S.

    2017-01-01

    The heat effects of the interaction between a solution of α-aminobutyric acid and solutions of HNO3 and KOH are measured by means of calorimetry in different ranges of pH at 298.15 K and values of ionic strength of 0.25, 0.5, and 0.75 (KNO3). The heat effects of the stepwise dissociation of the amino acid are determined. Standard thermodynamic characteristics (Δr H 0, Δr G 0, and Δr S 0) of the reactions of acid-base interaction in aqueous solutions of α-aminobutyric acid are calculated. The connection between the thermodynamic characteristics of the dissociation of the amino acid and the structure of this compound is considered.

  15. 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.

  16. 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.

  17. Secretion of acid and base equivalents by intact distal airways.

    PubMed

    Inglis, S K; Wilson, S M; Olver, R E

    2003-05-01

    Secretion of HCO(3)(-) by airway submucosal glands is essential for normal liquid and mucus secretion. Because the liquid bathing the airway surface (ASL) is acidic, it has been proposed that the surface epithelium may acidify HCO(3)(-)-rich glandular fluid. The aim of this study was to investigate the mechanisms by which intact distal bronchi, which contain both surface and glandular epithelium, modify pH of luminal fluid. Distal bronchi were isolated from pig lungs, cannulated in a bath containing HCO(3)(-)-buffered solution, and perfused continually with an aliquot of similar, lightly buffered solution (LBS) in which NaCl replaced NaHCO(3)(-) (pH 7 with NaOH). The pH of this circulating LBS initially acidified (by 0.053 +/- 0.0053 pH units) and transepithelial potential difference (PD) depolarized. The magnitude of acidification was increased when pH(LBS) was higher. This acidification was unaffected by luminal dimethylamiloride (DMA, 100 microM) but was inhibited by 100 nM bafilomycin A(1) (by 76 +/- 13%), suggesting involvement of vacuolar-H(+) ATPase. Addition of ACh (10 microM) evoked alkalinization of luminal LBS and hyperpolarization of transepithelial PD. The alkalinization was inhibited in HCO(3)(-)-free solutions containing acetazolamide (1 mM) and by DMA and was enhanced by bumetanide (100 microM), an inhibitor of Cl(-) secretion. The hyperpolarization was unaffected by these maneuvers. The anion channel blocker 5-nitro-2-(3-phenylpropylamino)benzoate (300 microM) and combined treatment with DMA and bumetanide blocked both the alkalinization and hyperpolarization responses to ACh. These results are consistent with earlier studies showing that ACh evokes glandular secretion of HCO(3)(-) and Cl(-). Isolated distal airways thus secrete both acid and base equivalents.

  18. 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.

  19. Integrated Microfluidic System Based on Electrowetting and its Application to Amino Acid Sensing Based on Electrochemiluminescence

    NASA Astrophysics Data System (ADS)

    Hosono, Hiroki; Satoh, Wataru; Suzuki, Hiroaki

    A microfluidic system to transport and mix solutions was fabricated and used for the detection of amino acids. A solution filled in the injection port was transported through a space between an elongated gold working electrode and a protruding structure of polydimethylsiloxane (PDMS). The transport was possible because the electrode surface was made hydrophilic by changing the potential of the gold working electrode. The same principle was used to mix two solutions. To demonstrate the system's applicability, optical biosensing based on electrochemiluminescence (ECL) was conducted on the chip. A necessary reagent solution (Ru(bpy)32+) and a sample solution (amino acid) were transported and mixed. ECL was observed on a platinum working electrode by applying a positive potential. Linear relationships were observed between the ECL intensity and the amino acid concentration.

  20. 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

  1. 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.

  2. 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.

  3. Bicarbonate-sensing soluble adenylyl cyclase is an essential sensor for acid/base homeostasis

    PubMed Central

    Tresguerres, Martin; Parks, Scott K.; Salazar, Eric; Levin, Lonny R.; Goss, Greg G.; Buck, Jochen

    2009-01-01

    pH homeostasis is essential for life, yet it remains unclear how animals sense their systemic acid/base (A/B) status. Soluble adenylyl cyclase (sAC) is an evolutionary conserved signaling enzyme that produces the second messenger cAMP in response to bicarbonate ions (HCO3−). We cloned the sAC ortholog from the dogfish, a shark that regulates blood A/B by absorbing and secreting protons (H+) and HCO3− at its gills. Similar to mammalian sAC, dogfish soluble adenylyl cyclase (dfsAC) is activated by HCO3− and can be inhibited by two structurally and mechanistically distinct small molecule inhibitors. dfsAC is expressed in the gill epithelium, where the subset of base-secreting cells resides. Injection of inhibitors into animals under alkaline stress confirmed that dfsAC is essential for maintaining systemic pH and HCO3− levels in the whole organism. One of the downstream effects of dfsAC is to promote the insertion of vacuolar proton pumps into the basolateral membrane to absorb H+ into the blood. sAC orthologs are present throughout metazoans, and mammalian sAC is expressed in A/B regulatory organs, suggesting that systemic A/B sensing via sAC is widespread in the animal kingdom. PMID:20018667

  4. Bicarbonate-sensing soluble adenylyl cyclase is an essential sensor for acid/base homeostasis.

    PubMed

    Tresguerres, Martin; Parks, Scott K; Salazar, Eric; Levin, Lonny R; Goss, Greg G; Buck, Jochen

    2010-01-05

    pH homeostasis is essential for life, yet it remains unclear how animals sense their systemic acid/base (A/B) status. Soluble adenylyl cyclase (sAC) is an evolutionary conserved signaling enzyme that produces the second messenger cAMP in response to bicarbonate ions (HCO(3)(-)). We cloned the sAC ortholog from the dogfish, a shark that regulates blood A/B by absorbing and secreting protons (H(+)) and HCO(3)(-) at its gills. Similar to mammalian sAC, dogfish soluble adenylyl cyclase (dfsAC) is activated by HCO(3)(-) and can be inhibited by two structurally and mechanistically distinct small molecule inhibitors. dfsAC is expressed in the gill epithelium, where the subset of base-secreting cells resides. Injection of inhibitors into animals under alkaline stress confirmed that dfsAC is essential for maintaining systemic pH and HCO(3)(-) levels in the whole organism. One of the downstream effects of dfsAC is to promote the insertion of vacuolar proton pumps into the basolateral membrane to absorb H(+) into the blood. sAC orthologs are present throughout metazoans, and mammalian sAC is expressed in A/B regulatory organs, suggesting that systemic A/B sensing via sAC is widespread in the animal kingdom.

  5. Status-based rejection sensitivity among asian americans: implications for psychological distress.

    PubMed

    Chan, Wayne; Mendoza-Denton, Rodolfo

    2008-10-01

    We examined whether anxious expectations of discrimination among Asian Americans can help explain this group's elevated levels of internalizing symptomatology, such as lower self-esteem (Twenge & Crocker, 2002) and higher depressive symptoms (Okazaki, 1997, 2002) relative to European Americans. Study 1 reports on the development and validation of a scale measuring status-based rejection sensitivity among Asian Americans (RS-A). In Study 2, scores on the RS-A were related to spontaneous discrimination attributions specifically in situations where discrimination is both applicable and possible for Asian Americans. Study 3 revealed that shame mediated the relationship between RS-A and internalizing symptomatology. Implications for well-being and intergroup interactions are discussed.

  6. Taxonomic status and phylogenetic relationship of tits based on mitogenomes and nuclear segments.

    PubMed

    Li, Xuejuan; Lin, Liliang; Cui, Aiming; Bai, Jie; Wang, Xiaoyang; Xin, Chao; Zhang, Zhen; Yang, Chao; Gao, Ruirui; Huang, Yuan; Lei, Fumin

    2016-11-01

    The phylogeny of tits has been studied using various molecular markers, but their phylogenetic relationships remain controversial. To further investigate their taxonomic status and phylogenetic relationships, the entire mitochondrial genomes (mitogenomes) and five nuclear segments were sequenced from 10 species of tits and two outgroups (Sylviparus modestus and Remiz consobrinus), followed by the comparison of mitogenomic characteristics and reconstruction of phylogenetic relationship based on the different datasets. The results revealed the following: the mitogenomes of 10 ingroup tits, each 16,758-16,799bp in length, displayed typical mitogenome organization and the gene order found in most previously determined Passeriformes mitogenomes; close relationships existed between Parus major and P. monticolus, between P. montanus and P. palustris, and between P. ater and P. venustulus; and Pseudopodoces humilis was a sister group to P. spilonotus, P. cyanus, or the clade containing P. major and P. monticolus.

  7. 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.

  8. Effect of nitric oxide on neointimal hyperplasia based on sex and hormone status.

    PubMed

    Hogg, Melissa E; Varu, Vinit N; Vavra, Ashley K; Popowich, Daniel A; Banerjee, Monisha N; Martinez, Janet; Jiang, Qun; Saavedra, Joseph E; Keefer, Larry K; Kibbe, Melina R

    2011-05-01

    Nitric oxide (NO)-based therapies decrease neointimal hyperplasia; however, studies have been performed only in male animal models. Thus, we sought to evaluate the effect of NO on vascular smooth muscle cells (VSMC) in vitro and neointimal hyperplasia in vivo based on sex and hormone status. In hormone-replete medium, male VSMC proliferated at greater rates than female VSMC. In hormone-depleted medium, female VSMC proliferated at greater rates than male VSMC. However, in both hormone environments, NO inhibited proliferation and migration to a greater extent in male compared to female VSMC. These findings correlated with greater G₀/G₁ cell cycle arrest and changes in cell cycle protein expression in male compared to female VSMC after exposure to NO. Next, the rat carotid artery injury model was used to assess the effect of NO on neointimal hyperplasia in vivo. Consistent with the in vitro data, NO was significantly more effective at inhibiting neointimal hyperplasia in hormonally intact males compared to females using weight-based dosing. An increased weight-based dose of NO in females was able to achieve efficacy equal to that in males. Surprisingly, NO was less effective at inhibiting neointimal hyperplasia in castrated animals of both sexes. In conclusion, these data suggest that NO inhibits neointimal hyperplasia more effectively in males compared to females and in hormonally intact compared to castrated rats, indicating that the effects of NO in the vasculature may be sex- and hormone-dependent.

  9. 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.

  10. Effect of casein-based semi-synthetic food on renal acid excretion and acid-base state of blood in dogs.

    PubMed

    Zijlstra, W G; Langbroek, A J; Kraan, J; Rispens, P; Nijmeijer, A

    1995-01-01

    Urinary acid excretion and blood acid-base state were determined in dogs fed a casein-based semi-synthetic food (SSF), to which different amounts of salts had been added, in comparison with feeding normal dog food. Net acid excretion (NAE) and inorganic acid excretion (IAE) increased during SSF feeding. IAE was higher than the acid load calculated from the sulphur and phosphorus content of the casein. This higher IAE appeared to be due to the presence of calcium and magnesium phosphate in the diet, because calcium and magnesium may be in part precipitated as carbonate, leaving phosphate to be absorbed as phosphoric acid. Acid excretion decreased by addition of CaO. When no neutral Na+ and K+ salts were added, the increase in NAE was accompanied by a metabolic acidosis. K+ was more effective in attenuating the acidosis than Na+. On the basis of these findings a diet can be made which imposes a known acid load, and provides stable baseline values. Hence, any additions that influence the acid-base balance can be properly studied. The data obtained in these and future studies utilising this diet may be of help in optimising the composition of nutrient solutions to be used in the care of critically ill patients.

  11. 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 ...

  12. 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.

  13. 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.

  14. 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.

  15. 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 ...

  16. An elementary derivation of the hard/soft-acid/base principle.

    PubMed

    Ayers, Paul W

    2005-04-08

    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.

  17. 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.

  18. 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.

  19. Maternal Multiple Micronutrient Supplementation Has Limited Impact on Micronutrient Status of Bangladeshi Infants Compared with Standard Iron Folic Acid Supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined the impact of type of maternal micronutrient supplement, time of introduction of a prenatal food supplement and the two interventions combined on micronutrient status of infants in rural Bangladesh. In a community trial, 4436 pregnant women were randomized to Early or Usual start of food...

  20. 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

  1. [Detection of amino acids based on terahertz spectroscopy].

    PubMed

    Tang, Zhong-feng; Lin, Hai-tao; Chen, Xiao-wei; Zhang, Zeng-fang

    2009-09-01

    Terahertz (THz) is the frequency region ranging from 0.1 to 2.0 THz, which lies in the far-infrared region. Compared to Fourier transform infrared spectra (FTIR), terahertz time-domain spectra (THz-TDS) has low energy, high signal-to-noise ratio (SNR) and is non-ionizing radiation. Low-frequency vibrational modes of some amino acids, such as torsional and collective vibrational modes and hydrogen-bond modes, exist in the THz region. Amino acids are important organic compounds and are the fundamental components of proteins. Amino acids can exist with a highly ordered crystal structure linked by hydrogen intermolecular bonds in the solid phase. The absorption spectra of amino acids in the THz region show marked differences while mid-infrared absorption spectra usually show very little difference. Up to now, absorption spectra of twenty kinds of amino acids have been studied by many researchers using THz technique; the quantitative analysis of amino acids by THZ-TDS is also included. Investigation of THz spectra of amino acids are of fundamental interests, and will lead to further understanding of low-frequency vibrations of protein/DNA and relevant biological reactions and activities. In the present paper, the latest progress in absorption spectra of amino acids determined by THz spectroscopy is reviewed and a database is built. Some brief remarks on future developments in and prospects for THz application in amino acids are also provided.

  2. 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.

  3. 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)

  4. 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…

  5. 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

  6. Ligation of the left aorta in alligators affects acid-base balance: a role for the R→L shunt.

    PubMed

    Gardner, Manuela N; Sterba-Boatwright, Blair; Jones, David R

    2011-09-15

    This study investigated the effects of preventing bulk flow from the right ventricle to the body via the left aorta (LAo; right to left shunt, R→L) on acid-base status in alligators following feeding, during long-term fasting and a cold temperature exposure. Post-feeding pHv and [Formula: see text] were not significantly different between S and C. Post-feeding pHv increased in both groups of alligators, but not significantly. During fasting, all acid-base variables were similar between the two groups of alligators. A 10 °C reduction in environmental temperature resulted in a significant difference in pHv and HCO3- between S and C. Both pHv and HCO3- were significantly higher in C animals. PV(CO2) significantly decreased in both groups during the cold exposure. Preventing the R→L shunt via the LAo had significant effects on acid-base balance in alligators indicating incomplete compensation for its loss and a role for the LAo in metabolic homeostasis.

  7. 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.

  8. Protection against discrimination based on HIV/AIDS status in Canada: the legal framework.

    PubMed

    Elliott, Richard; Gold, Jennifer

    2005-04-01

    Respecting, protecting ,and fulfilling the human rights of people living with, and vulnerable to, HIV/AIDS has been recognized as an essential element of ethical and effective responses to the epidemic. Human rights law provides one critical tool for implementing a human rights-based approach to HIV/AIDS. Freedom from discrimination is a foundational human rights principle, and is a touchstone of both international and domestic human rights law. This article examines the ways in which Canadian law currently protects people against discrimination based on HIV/AIDS status. The article also reviews the equality rights provision of the Canadian Charter of Rights and Freedoms; federal, provincial, and territorial anti-discrimination statutes and policies; and some of the key cases that have applied and developed these legislative protections. Finally, the article looks at the issue of remedies for discrimination under Canadian law. (Other forms of discrimination relevant to people living with HIV/AIDS--specifically, discrimination based on grounds relevant to people from groups disproportionately affected by HIV/AIDS-related stigma--will be analyzed in similar detail in a future issue of the Review.)

  9. 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.

  10. 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.

  11. Teaching Brønsted-Lowry Acid-Base Theory in a Direct Comprehensive Way

    NASA Astrophysics Data System (ADS)

    Adcock, Jamie L.

    2001-11-01

    A figure is presented which shows in a comprehensive way the relationships between Brønsted-Lowry acids and their conjugate bases. It shows their interactions with water and quantifies the terms strong, weak, and very weak, showing precisely how these modifiers can be effectively used to indicate the nature of the reaction between any conjugate acid/base and water. It shows that ion hydrolysis is simple acid/base behavior, and it clearly suggests the leveling effect of water on strong acids and bases.

  12. Improving Pharmacy Students' Understanding and Long-term Retention of Acid-Base Chemistry

    PubMed Central

    2007-01-01

    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 PMID:19503706

  13. Pre-storage application of oxalic acid alleviates chilling injury in mango fruit by modulating proline metabolism and energy status under chilling stress.

    PubMed

    Li, Peiyan; Zheng, Xiaolin; Liu, Yan; Zhu, Yuyan

    2014-01-01

    Effects of oxalic acid on chilling injury, proline metabolism and energy status in mango fruit were investigated after mango fruit (Mangifera indica L. cv. Zill) were dipped in 5mM oxalic acid solution for 10min at 25°C and then stored at low temperature (10±0.5°C) for 49days thereafter transferred to 25°C for 4days. Pre-storage application of oxalic acid apparently inhibited the development of chilling injury, notably elevated proline accumulation actually associated with increase in Δ(1)-pyrroline-5-carboxylate synthetase (P5CS) activity and decrease in proline dehydrogenase (PDH) activity in the peel and the flesh, without activation of ornithine-δ-aminotransferase (OAT) activity, and maintained high ATP level and energy charge in the flesh during storage. It was suggested that these effects of oxalic acid might collectively contribute to improving chilling tolerance, thereby alleviating chilling injury and maintaining quality of mango fruit in long term cold storage.

  14. A cupric silver histochemical analysis of domoic acid damage to olfactory pathways following status epilepticus in a rat model for chronic recurrent spontaneous seizures and aggressive behavior.

    PubMed

    Tiedeken, Jessica A; Muha, Noah; Ramsdell, John S

    2013-01-01

    The amnesic shellfish toxin, domoic acid, interferes with glutamatergic pathways leading to neuronal damage, most notably causing memory loss and seizures. In this study, the authors utilized a recently developed rat model for domoic acid-induced epilepsy, an emerging disease appearing in California sea lions weeks to months after poisoning, to identify structural damage that may lead to a permanent epileptic state. Sprague Dawley rats were kindled with several low hourly intraperitoneal doses of domoic acid until a state of status epilepticus (SE) appears. This kindling approach has previously been shown to induce a permanent state of epileptic disease in 96% animals within 6 months. Three animals were selected for neurohistology a week after the initial SE. An amino cupric silver staining method using neutral red counterstain was used on every eighth 40 µm coronal section from each brain to highlight neural degeneration from the olfactory bulb through the brain stem. The most extensive damage was found in the olfactory bulb and related olfactory pathways, including the anterior/medial olfactory cortices, endopiriform nucleus, and entorhinal cortex. These findings indicate that damage to olfactory pathways is prominent in a rat model for domoic acid-induced chronic recurrent spontaneous seizures and aggressive behavior.

  15. 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

  16. [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.

  17. Modeling the Acid-Base Properties of Montmorillonite Edge Surfaces.

    PubMed

    Tournassat, Christophe; Davis, James A; Chiaberge, Christophe; Grangeon, Sylvain; Bourg, Ian C

    2016-12-20

    The surface reactivity of clay minerals remains challenging to characterize because of a duality of adsorption surfaces and mechanisms that does not exist in the case of simple oxide surfaces: edge surfaces of clay minerals have a variable proton surface charge arising from hydroxyl functional groups, whereas basal surfaces have a permanent negative charge arising from isomorphic substitutions. Hence, the relationship between surface charge and surface potential on edge surfaces cannot be described using the Gouy-Chapman relation, because of a spillover of negative electrostatic potential from the basal surface onto the edge surface. While surface complexation models can be modified to account for these features, a predictive fit of experimental data was not possible until recently, because of uncertainty regarding the densities and intrinsic pKa values of edge functional groups. Here, we reexamine this problem in light of new knowledge on intrinsic pKa values obtained over the past decade using ab initio molecular dynamics simulations, and we propose a new formalism to describe edge functional groups. Our simulation results yield reasonable predictions of the best available experimental acid-base titration data.

  18. Regulation of Connexin-Based Channels by Fatty Acids.

    PubMed

    Puebla, Carlos; Retamal, Mauricio A; Acuña, Rodrigo; Sáez, Juan C

    2017-01-01

    In this mini-review, we briefly summarize the current knowledge about the effects of fatty acids (FAs) on connexin-based channels, as well as discuss the limited information about the impact FAs may have on pannexins (Panxs). FAs regulate diverse cellular functions, some of which are explained by changes in the activity of channels constituted by connexins (Cxs) or Panxs, which are known to play critical roles in maintaining the functional integrity of diverse organs and tissues. Cxs are transmembrane proteins that oligomerize into hexamers to form hemichannels (HCs), which in turn can assemble into dodecamers to form gap junction channels (GJCs). While GJCs communicate the cytoplasm of contacting cells, HCs serve as pathways for the exchange of ions and small molecules between the intra and extracellular milieu. Panxs, as well as Cx HCs, form channels at the plasma membrane that enable the interchange of molecules between the intra and extracellular spaces. Both Cx- and Panx-based channels are controlled by several post-translational modifications. However, the mechanism of action of FAs on these channels has not been described in detail. It has been shown however that FAs frequently decrease GJC-mediated cell-cell communication. The opposite effect also has been described for HC or Panx-dependent intercellular communication, where, the acute FA effect can be reversed upon washout. Additionally, changes in GJCs mediated by FAs have been associated with post-translational modifications (e.g., phosphorylation), and seem to be directly related to chemical properties of FAs (e.g., length of carbon chain and/or degree of saturation), but this possible link remains poorly understood.

  19. Regulation of Connexin-Based Channels by Fatty Acids

    PubMed Central

    Puebla, Carlos; Retamal, Mauricio A.; Acuña, Rodrigo; Sáez, Juan C.

    2017-01-01

    In this mini-review, we briefly summarize the current knowledge about the effects of fatty acids (FAs) on connexin-based channels, as well as discuss the limited information about the impact FAs may have on pannexins (Panxs). FAs regulate diverse cellular functions, some of which are explained by changes in the activity of channels constituted by connexins (Cxs) or Panxs, which are known to play critical roles in maintaining the functional integrity of diverse organs and tissues. Cxs are transmembrane proteins that oligomerize into hexamers to form hemichannels (HCs), which in turn can assemble into dodecamers to form gap junction channels (GJCs). While GJCs communicate the cytoplasm of contacting cells, HCs serve as pathways for the exchange of ions and small molecules between the intra and extracellular milieu. Panxs, as well as Cx HCs, form channels at the plasma membrane that enable the interchange of molecules between the intra and extracellular spaces. Both Cx- and Panx-based channels are controlled by several post-translational modifications. However, the mechanism of action of FAs on these channels has not been described in detail. It has been shown however that FAs frequently decrease GJC-mediated cell-cell communication. The opposite effect also has been described for HC or Panx-dependent intercellular communication, where, the acute FA effect can be reversed upon washout. Additionally, changes in GJCs mediated by FAs have been associated with post-translational modifications (e.g., phosphorylation), and seem to be directly related to chemical properties of FAs (e.g., length of carbon chain and/or degree of saturation), but this possible link remains poorly understood. PMID:28174541

  20. Increasing intakes of the long-chain omega-3 docosahexaenoic acid: effects on platelet functions and redox status in healthy men.

    PubMed

    Guillot, Nicolas; Caillet, Emilie; Laville, Martine; Calzada, Catherine; Lagarde, Michel; Véricel, Evelyne

    2009-09-01

    Docosahexaenoic acid (DHA) can prevent cardiovascular events. However, few studies have addressed the effects of DHA on both platelet reactivity and redox status in healthy subjects, and dose-related studies are scarce. The main objectives of the present study were to determine the effects of increasing doses of DHA on platelets and redox status in humans. Twelve healthy male volunteers (aged 53-65 yr) were assigned to consume an intake of successively 200, 400, 800, and 1600 mg/d DHA, as the only omega-3 fatty acid, for 2 wk each dose. Blood and urine samples were collected before and after each dose of DHA and at 8 wk after arrest of supplementation. DHA was incorporated in a dose-response fashion in platelet phospholipids. After supplementation with 400 and 800 mg/d DHA, platelet reactivity was significantly decreased. Platelet vitamin E concentration increased only after 200 mg/d DHA, while p38 MAP kinase phosphorylation decreased. Urinary isoprostane was also significantly lowered after 200 mg/d DHA but was increased after 1600 mg/d. Therefore, supplementation with only 200 mg/d DHA for 2 wk induced an antioxidant effect. It is concluded that low consumption of DHA could be an effective and nonpharmacological way to protect healthy men from platelet-related cardiovascular events.

  1. A low omega-6 polyunsaturated fatty acid (n-6 PUFA) diet increases omega-3 (n-3) long chain PUFA status in plasma phospholipids in humans.

    PubMed

    Wood, K E; Lau, A; Mantzioris, E; Gibson, R A; Ramsden, C E; Muhlhausler, B S

    2014-04-01

    This study aimed to determine the effect of reducing the dietary linoleic acid (LA) intake from ~5% to <2.5% energy (%E) on n-3 long chain PUFA (LCPUFA) status in humans. Thirty-six participants followed a <2.5%E LA diet for 4 weeks. Nutrient intakes were estimated from diet diaries and blood samples were collected for assessment of fatty acid composition in plasma and erythrocyte phospholipids. LA intakes were reduced from 4.6%E to 2%E during the low LA intervention (P<0.001) while n-3 LCPUFA intakes were unchanged. LA and total n-6 PUFA content of plasma and erythrocyte phospholipids were significantly reduced after the low LA diet phase (P<0.001). The n-3 LCPUFA content of plasma phospholipids was significantly increased after the low LA diet compared to baseline (6.22% vs. 5.53%, P<0.001). These data demonstrate that reducing LA intake for 4 weeks increases n-3 LCPUFA status in humans in the absence of increased n-3 LCPUFA intake.

  2. Gas-phase acid-base properties of melamine and cyanuric acid.

    PubMed

    Mukherjee, Sumit; Ren, Jianhua

    2010-10-01

    The thermochemical properties of melamine and cyanuric acid were characterized using mass spectrometry measurements along with computational studies. A triple-quadrupole mass spectrometer was employed with the application of the extended Cooks kinetic method. The proton affinity (PA), gas-phase basicity (GB), and protonation entropy (Δ(p)S) of melamine were determined to be 226.2 ± 2.0 kcal/mol, 218.4 ± 2.0 kcal/mol, and 26.2 ± 2.0 cal/mol K, respectively. The deprotonation enthalpy (Δ(acid)H), gas-phase acidity (Δ(acid)G), and deprotonation entropy (Δ(acid)S) of cyanuric acid were determined to be 330.7 ± 2.0 kcal/mol, 322.9 ± 2.0 kcal/mol, and 26.1 ± 2.0 cal/mol K, respectively. The geometries and energetics of melamine, cyanuric acid, and related ionic species were calculated at the B3LYP/6-31+G(d) level of theory. The computationally predicted proton affinity of melamine (225.9 kcal/mol) and gas-phase deprotonation enthalpy of cyanuric acid (328.4 kcal/mol) agree well with the experimental results. Melamine is best represented as the imide-like triazine-triamine form and the triazine nitrogen is more basic than the amino group nitrogen. Cyanuric acid is best represented as the keto-like tautomer and the N-H group is the most probable proton donor.

  3. HIV-1 Amino Acid Changes Among Participants With Virologic Failure: Associations With First-line Efavirenz or Atazanavir Plus Ritonavir and Disease Status

    PubMed Central

    Mollan, Katie; Daar, Eric S.; Sax, Paul E.; Balamane, Maya; Collier, Ann C.; Fischl, Margaret A.; Lalama, Christina M.; Bosch, Ronald J.; Tierney, Camlin; Katzenstein, David

    2012-01-01

    Background. Although specific human immunodeficiency virus type 1 (HIV-1) drug resistance mutations are well studied, little is known about cumulative amino acid changes, or how regimen and participant characteristics influence these changes. Methods. In the AIDS Clinical Trials Group randomized study A5202 of treatment-naive HIV-infected participants, cumulative HIV-1 amino acid changes from pretreatment to virologic failure were evaluated in protease and reverse transcriptase (RT) gene sequences. Results. Among 265 participants with virologic failure, those assigned atazanavir plus ritonavir (ATV/r) did not have significantly more protease changes compared with those assigned efavirenz (EFV) (P ≥ .13). In contrast, participants with virologic failure assigned EFV had more RT changes, including and excluding known resistance codons (P < .001). At pretreatment, lower CD4 cell count, major resistance, more amino acid mixtures (all P < .001), hepatitis C antibody negativity (P = .05), and black race/ethnicity (P = .02) were associated with more HIV-1 amino acid changes. Conclusions. Virologic failure following EFV-containing treatment was associated with more HIV-1 amino acid changes compared to failure of ATV/r-containing treatment. Furthermore, we show that non–drug resistance mutations occurred more frequently among those failing EFV, the clinical relevance of which warrants further investigation. Pretreatment immunologic status may play a role in viral evolution during treatment, as evidenced by increased amino acid changes among those with lower pretreatment CD4 count. Clinical Trials Registration. NCT00118898. PMID:23148287

  4. 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...

  5. Wheat flour based propionic acid fermentation: an economic approach.

    PubMed

    Kagliwal, Lalit D; Survase, Shrikant A; Singhal, Rekha S; Granström, Tom

    2013-02-01

    A process for the fermentative production of propionic acid from whole wheat flour using starch and gluten as nutrients is presented. Hydrolysis of wheat flour starch using amylases was optimized. A batch fermentation of hydrolysate supplemented with various nitrogen sources using Propionibacterium acidipropionici NRRL B 3569 was performed. The maximum production of 48.61, 9.40, and 11.06 g of propionic acid, acetic acid and succinic acid, respectively, was found with wheat flour hydrolysate equivalent to 90 g/l glucose and supplemented with 15 g/l yeast extract. Further, replacement of yeast extract with wheat gluten hydrolysate showed utilization of gluten hydrolysate without compromising the yields and also improving the economics of the process. The process so developed could be useful for production of animal feed from whole wheat with in situ production of preservatives, and also suggest utilization of sprouted or germinated wheat for the production of organic acids.

  6. High Performance Fatty Acid-Based Vinyl Ester Resin for Liquid Molding

    DTIC Science & Technology

    2007-07-01

    Diglycidyl ether of bisphenol-A ( DGEBA ) Methacrylic Acid Figure 1: The reaction of DGEBA and methacrylic acid to produce the vinyl ester 2.3...High Performance Fatty Acid -Based Vinyl Ester Resin for Liquid Molding by Xing Geng, John J. La Scala, James M. Sands, and Giuseppe R...it to the originator. Army Research Laboratory Aberdeen Proving Ground, MD 21005-5069 ARL-RP-184 July 2007 High Performance Fatty Acid

  7. Efficient production of free fatty acids from ionic liquid-based acid- or enzyme-catalyzed bamboo hydrolysate.

    PubMed

    Mi, Le; Qin, Dandan; Cheng, Jie; Wang, Dan; Li, Sha; Wei, Xuetuan

    2017-03-01

    Two engineered Escherichia coli strains, DQ101 (MG1655 fadD (-))/pDQTES and DQ101 (MG1655 fadD (-))/pDQTESZ were constructed to investigate the free fatty acid production using ionic liquid-based acid- or enzyme-catalyzed bamboo hydrolysate as carbon source in this study. The plasmid, pDQTES, carrying an acyl-ACP thioesterase 'TesA of E. coli in pTrc99A was constructed firstly, and then (3R)-hydroxyacyl-ACP dehydratase was ligated after the TesA to give the plasmid pDQTESZ. These two strains exhibited efficient fatty acid production when glucose was used as the sole carbon source, with a final concentration of 2.45 and 3.32 g/L, respectively. The free fatty acid production of the two strains on xylose is not as efficient as that on glucose, which was 2.32 and 2.96 g/L, respectively. For mixed sugars, DQ101 (MG1655 fadD (-))-based strains utilized glucose and pentose sequentially under the carbon catabolite repression (CCR) regulation. The highest total FFAs concentration from the mixed sugar culture reached 2.81 g/L by DQ101 (MG1655 fadD (-))/pDQTESZ. Furthermore, when ionic liquid-based enzyme-catalyzed bamboo hydrolysate was used as the carbon source, the strain DQ101 (MG1655 fadD (-))/pDQTESZ could produce 1.23 g/L FFAs with a yield of 0.13 g/g, and while it just produced 0.65 g/L free fatty acid with the ionic liquid-based acid-catalyzed bamboo hydrolysate as the feedstock. The results suggested that enzymatic catalyzed bamboo hydrolysate with ionic liquid pretreatment could serve as an efficient feedstock for free fatty acid production.

  8. Role of Omega-3 Fatty Acids in the Etiology, Treatment, and Prevention of Depression: Current Status and Future Directions.

    PubMed

    McNamara, Robert K

    2016-09-01

    Over the past three decades a body of translational evidence has implicated dietary deficiency in long-chain omega-3 (LCn-3) fatty acids, including eicosapenaenoic acid (EPA) and docosahexaenoic acid (DHA), in the pathophysiology and etiology of major depressive disorder (MDD). Cross-national and cross-sectional data suggest that greater habitual intake of preformed EPA+DHA is associated with reduced risk for developing depressive symptoms and syndromal MDD. Erythrocyte EPA and DHA composition is highly correlated with habitual fish or fish oil intake, and case-control studies have consistently observed lower erythrocyte EPA and/or DHA levels in patients with MDD. Low erythrocyte EPA+DHA composition may also be associated with increased risk for suicide and cardiovascular disease, two primary causes of excess premature mortality in MDD. While controversial, dietary EPA+DHA supplementation may have antidepressant properties and may augment the therapeutic efficacy of antidepressant medications. Neuroimaging and rodent neurodevelopmental studies further suggest that low LCn-3 fatty acid intake or biostatus can recapitulate central pathophysiological features associated with MDD. Prospective findings suggest that low LCn-3 fatty acid biostatus increases risk for depressive symptoms in part by augmenting pro-inflammatory responsivity. When taken collectively, these translational findings provide a strong empirical foundation in support of dietary LCn-3 fatty acid deficiency as a modifiable risk factor for MDD. This review provides an overview of this translational evidence and then discusses future directions including strategies to translate this evidence into routine clinical screening and treatment algorithms.

  9. Long-term intermittent multiple micronutrient supplementation enhances hemoglobin and micronutrient status more than iron + folic acid supplementation in Bangladeshi rural adolescent girls with nutritional anemia.

    PubMed

    Ahmed, Faruk; Khan, Moududur R; Akhtaruzzaman, Mohammad; Karim, Rezaul; Williams, Gail; Torlesse, Harriet; Darnton-Hill, Ian; Dalmiya, Nita; Banu, Cadi P; Nahar, Badrun

    2010-10-01

    Previous short-term supplementation studies showed no additional hematologic benefit of multiple micronutrients (MMN) compared with iron + folic acid (IFA) in adolescent girls. This study examines whether long-term once- or twice-weekly supplementation of MMN can improve hemoglobin (Hb) and micronutrient status more than twice-weekly IFA supplementation in anemic adolescent girls in Bangladesh. Anemic girls (n = 324) aged 11-17 y attending rural schools were given once- or twice-weekly MMN or twice-weekly IFA, containing 60 mg iron/dose in both supplements, for 52 wk in a randomized double-blind trial. Blood samples were collected at baseline and 26 and 52 wk. Intent to treat analysis showed no significant difference in the Hb concentration between treatments at either 26 or 52 wk. However, after excluding girls with hemoglobinopathy and adjustment for baseline Hb, a greater increase in Hb was observed with twice-weekly MMN at 26 wk (P = 0.045). Although all 3 treatments effectively reduced iron deficiency, once-weekly MMN produced significantly lower serum ferritin concentrations than the other treatments at both 26 and 52 wk. Both once- and twice-weekly MMN significantly improved riboflavin, vitamin A, and vitamin C status compared with IFA. Overall, once-weekly MMN was less efficacious than twice-weekly MMN in improving iron, riboflavin, RBC folic acid, and vitamin A levels. Micronutrient supplementation beyond 26 wk was likely important in sustaining improved micronutrient status. These findings highlight the potential usefulness of MMN intervention in this population and have implications for programming.

  10. Ammonia Catalyzed Formation of Sulfuric Acid in Troposphere: The Curious Case of A Base Promoting Acid Rain.

    PubMed

    Bandyopadhyay, Biman; Kumar, Pradeep; Biswas, Partha

    2017-04-03

    Electronic structure calculations have been performed to investigate the role of ammonia in catalyzing the formation of sulfuric acid through hydrolysis of SO3 in Earth's atmosphere. The uncatalyzed process involves a high activation barrier and, till date, is mainly known to occur in Earth's atmosphere only when catalyzed by water and acids. Here we show that hydrolysis of SO3 can be very efficiently catalyzed by ammonia, the most abundant basic component in Earth's atmosphere. It was found, based on magnitude of relative potential energies as well as rate coefficients, that ammonia is the best among all the catalysts studied until now (water and acids) and could be a considerable factor in formation of sulfuric acid in troposphere. The calculated rate coefficient (at 298 K) of ammonia catalyzed reaction has been found to be ~10^5 - 10^7 times greater than that for water catalyzed ones. It was found, based on relative rates of ammonia and water catalyzed processes that in troposphere ammonia, together with water, could be the key factor in determining the rate of formation of sulfuric acid. In fact ammonia could surpass water in catalyzing formation of sulfuric acid via hydrolysis of SO3 at various altitudes in troposphere depending upon their relative concentrations.

  11. Soil moisture status estimation over Three Gorges area with Landsat TM data based on temperature vegetation dryness index

    NASA Astrophysics Data System (ADS)

    Xu, Lina; Niu, Ruiqing; Li, Jiong; Dong, Yanfang

    2011-12-01

    Soil moisture is the important indicator of climate, hydrology, ecology, agriculture and other parameters of the land surface and atmospheric interface. Soil moisture plays an important role on the water and energy exchange at the land surface/atmosphere interface. Remote sensing can provide information on large area quickly and easily, so it is significant to do research on how to monitor soil moisture by remote sensing. This paper presents a method to assess soil moisture status using Landsat TM data over Three Gorges area in China based on TVDI. The potential of Temperature- Vegetation Dryness Index (TVDI) from Landsat TM data in assessing soil moisture was investigated in this region. After retrieving land surface temperature and vegetation index a TVDI model based on the features of Ts-NDVI space is established. And finally, soil moisture status is estimated according to TVDI. It shows that TVDI has the advantages of stability and high accuracy to estimating the soil moisture status.

  12. 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.

  13. Visual, base-specific detection of nucleic acid hybridization using polymerization-based amplification.

    PubMed

    Hansen, Ryan R; Johnson, Leah M; Bowman, Christopher N

    2009-03-15

    Polymerization-based signal amplification offers sensitive visualization of biotinylated biomolecules functionalized to glass microarrays in a manner suitable for point-of-care use. Here we report using this method for visual detection of multiplexed nucleic acid hybridizations from complex media and develop an application toward point mutation detection and single nucleotide polymorphism (SNP) typing. Primer extension reactions were employed to label selectively and universally all complementary surface DNA hybrids with photoinitiators, permitting simultaneous and dynamic photopolymerization from positive sites to 0.5-nM target concentrations. Dramatic improvements in signal ratios between complementary and mismatched hybrids enabled visual discrimination of single base differences in KRAS codon-12 biomarkers.

  14. 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.

  15. Dynamic wetting: status and prospective of single particle based experiments and simulations.

    PubMed

    Cappelli, S; Xie, Q; Harting, J; de Jong, A M; Prins, M W J

    2015-09-25

    The fundamental molecular and microscopic properties of materials leading to dynamic wetting and relaxation effects have been subject to numerous studies in the past decades, but a thorough understanding is still missing. While most previous experiments utilize fluids deposited on planar substrates, this article focuses on an attractive alternative based on single colloidal particles: colloidal particles have the ability to strongly interact with fluid-fluid interfaces and the behavior strongly depends on the surface properties of the particles and the fluids used. Recent progress in the manipulation and synthesis of colloidal particles with well-defined surface properties and shapes makes them ideal candidates to probe the fundamental surface properties leading to dynamic wetting effects. In this paper we review and discuss the status of experimental and numerical techniques to characterize the dynamic wetting of single particles at fluid-fluid interfaces, with the aim to assist scientists and engineers in the design of new experimental techniques and particle-based (bio)analytical tools.

  16. Development and commercialization status of Fe{sub 3}Al-based intermetallic alloys

    SciTech Connect

    Sikka, V.K.; Viswanathan, S.; McKamey, C.G.

    1993-06-01

    The Fe{sub 3}Al-based intermetallic alloys offer unique benefits of excellent oxidation and sulfidation resistance, limited by poor room-temperature (RT) ductility and low high-temperature strength. Recent understanding of environmental effects on RT ductility of these alloys has led to progress toward taking commercial advantage of Fe{sub 3}Al-based materials. Cause of low ductility appears to be related to hydrogen formed from reaction with moisture. The environmental effect has been reduced in these intermetallic alloys by two methods. The first deals with producing a more hydrogen-resistant microstructure through thermomechanical processing, and the second dealed with compositional modification. The alloys showing reduced environmental effect have been melted and processed by many different methods. Laboratory and commercial heats have been characterized. Tests have been conducted in both air and controlled environments to quantify environmental effects on these properties. These materials were also tested for aqueous corrosion and resistance to stress corrosion cracking. Oxidation and sulfidation data were generated and effects of minor alloying elements on were also investigated. Several applications have been identified for the newly developed iron aluminides. Commercialization status of these alloys is described.

  17. Changes in stature, weight, and nutritional status with tourism-based economic development in the Yucatan.

    PubMed

    Leatherman, Thomas L; Goodman, Alan H; Stillman, Tobias

    2010-07-01

    Over the past 40 years, tourism-based economic development has transformed social and economic conditions in the Yucatan Peninsula, Mexico. We address how these changes have influenced anthropometric indicators of growth and nutritional status in Yalcoba, a Mayan farming community involved in the circular migration of labor in the tourist economy. Data are presented on stature and weight for children measured in 1938 in the Yucatan Peninsula and from 1987 to 1998 in the Mayan community of Yalcoba. In addition, stature, weight and BMI are presented for adults in Yalcoba based on clinic records. Childhood stature varied little between 1938 and 1987. Between 1987 and 1998 average male child statures increased by 2.6cm and female child statures increased by 2.7cm. Yet, 65% of children were short for their ages. Between 1987 and 1998, average child weight increased by 1.8kg. Child BMIs were similar to US reference values and 13% were considered to be above average for weight. Forty percent of adult males and 64% of females were overweight or obese. The anthropometric data from Yalcoba suggest a pattern of stunted children growing into overweight adults. This pattern is found elsewhere in the Yucatan and in much of the developing world where populations have experienced a nutrition transition toward western diets and reduced physical activity levels.

  18. 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

  19. 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.

  20. 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.

  1. Proton exchange in acid-base complexes induced by reaction coordinates with heavy atom motions

    NASA Astrophysics Data System (ADS)

    Alavi, Saman; Taghikhani, Mahdi

    2012-06-01

    We extend previous work on nitric acid-ammonia and nitric acid-alkylamine complexes to illustrate that proton exchange reaction coordinates involve the rocking motion of the base moiety in many double hydrogen-bonded gas phase strong acid-strong base complexes. The complexes studied involve the biologically and atmospherically relevant glycine, formic, acetic, propionic, and sulfuric acids with ammonia/alkylamine bases. In these complexes, the magnitude of the imaginary frequencies associated with the proton exchange transition states are <400 cm-1. This contrasts with widely studied proton exchange reactions between symmetric carboxylic acid dimers or asymmetric DNA base pair and their analogs where the reaction coordinate is localized in proton motions and the magnitude of the imaginary frequencies for the transition states are >1100 cm-1. Calculations on complexes of these acids with water are performed for comparison. Variations of normal vibration modes along the reaction coordinate in the complexes are described.

  2. 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

  3. 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

    Wei, Wen-Hao; Dong, Xue-Meng; Liu, Chen-Guang

    2015-03-31

    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.

  4. Physical activity and physical activity adherence in the elderly based on smoking status.

    PubMed

    Cooper, Theodore V; Resor, Michelle R; Stoever, Colby J; Dubbert, Patricia M

    2007-10-01

    This study assessed the impact of current smoking status and lifetime smoking status on physical fitness and physical activity regimen adherence as part of a larger study on walking for exercise in elderly primary care patients at a Veterans Affairs Medical Center. At baseline, 218 participants self-reported smoking status which was verified by carbon monoxide expiration. Former and current smokers responded to questions about length of time quit, average daily cigarette intake, and years a smoker. Smoking measures were re-collected at 6- and 12-month follow-ups if the participants indicated a change in smoking status. Veterans completed multiple measures of physical activity (e.g., 6-min walk, 7-day Physical Activity Recall), and adherence to a physical activity goal was assessed. The Physical Component Summary (PCS) subscale of the Medical Outcomes Study Short Form-36 (MOS SF-36) was used to assess health-related quality of life. Hierarchical regression models indicated smoking status was a predictor of the baseline 6-min walk such that smokers walked significantly shorter distances than nonsmokers. In addition, smoking status was found to be a significant predictor of adherence; however, the overall model that included smoking status as a predictor did not demonstrate a significant effect on adherence. Neither smoking status nor pack years were predictors of baseline self-reported physical activity or changes in physical activity post intervention. Results are consistent with recommendations to use physical exercise as an aid to tobacco cessation, even in aging men with extensive smoking histories.

  5. Child's Weight Status and Parent's Response to a School-Based Body Mass Index Screening and Parent Notification Program

    ERIC Educational Resources Information Center

    Lee, Jiwoo; Kubik, Martha Y.

    2015-01-01

    This study examined the response of parents of elementary school-aged children to a school-based body mass index (BMI) screening and parent notification program conducted in one Minnesota school district in 2010-2011 and whether parent's response was moderated by child's weight status. Randomly selected parents (N = 122) of second- and…

  6. Docosahexaenoic acid and shore-based diets in hominin encephalization: a rebuttal.

    PubMed

    Cunnane, Stephen C; Plourde, Mélanie; Stewart, Kathy; Crawford, Michael A

    2007-01-01

    Carlson and Kingston ([2007]: Am J Hum Biol 19:132-141) propose that preformed dietary docosahexaenoic acid (an omega-3 fatty acid in fish) did not have a significant role in hominin encephalization. Their position hinges on claiming that humans are able to make sufficient docosahexaenoic acid from the plant-based "parent" omega-3 fatty acid-alpha-linolenic acid. They also suggest that hominin fish consumption occurred too late to have materially influenced encephalization. The authors quantify here a summary of the published data showing that humans cannot make sufficient docosahexaenoic acid to maintain normal infant brain development. The authors also provide evidence that the fossil record shows that some of the earliest hominins were regularly consuming fish. Hence, we reject Carlson and Kingston's position and reiterate support for the concept that access to shore-based diets containing docosahexaenoic acid was necessary for hominin encephalization beyond the level seen in the great apes.

  7. Status of the photomultiplier-based FlashCam camera for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Pühlhofer, G.; Bauer, C.; Eisenkolb, F.; Florin, D.; Föhr, C.; Gadola, A.; Garrecht, F.; Hermann, G.; Jung, I.; Kalekin, O.; Kalkuhl, C.; Kasperek, J.; Kihm, T.; Koziol, J.; Lahmann, R.; Manalaysay, A.; Marszalek, A.; Rajda, P. J.; Reimer, O.; Romaszkan, W.; Rupinski, M.; Schanz, T.; Schwab, T.; Steiner, S.; Straumann, U.; Tenzer, C.; Vollhardt, A.; Weitzel, Q.; Winiarski, K.; Zietara, K.

    2014-07-01

    The FlashCam project is preparing a camera prototype around a fully digital FADC-based readout system, for the medium sized telescopes (MST) of the Cherenkov Telescope Array (CTA). The FlashCam design is the first fully digital readout system for Cherenkov cameras, based on commercial FADCs and FPGAs as key components for digitization and triggering, and a high performance camera server as back end. It provides the option to easily implement different types of trigger algorithms as well as digitization and readout scenarios using identical hardware, by simply changing the firmware on the FPGAs. The readout of the front end modules into the camera server is Ethernet-based using standard Ethernet switches and a custom, raw Ethernet protocol. In the current implementation of the system, data transfer and back end processing rates of 3.8 GB/s and 2.4 GB/s have been achieved, respectively. Together with the dead-time-free front end event buffering on the FPGAs, this permits the cameras to operate at trigger rates of up to several ten kHz. In the horizontal architecture of FlashCam, the photon detector plane (PDP), consisting of photon detectors, preamplifiers, high voltage-, control-, and monitoring systems, is a self-contained unit, mechanically detached from the front end modules. It interfaces to the digital readout system via analogue signal transmission. The horizontal integration of FlashCam is expected not only to be more cost efficient, it also allows PDPs with different types of photon detectors to be adapted to the FlashCam readout system. By now, a 144-pixel mini-camera" setup, fully equipped with photomultipliers, PDP electronics, and digitization/ trigger electronics, has been realized and extensively tested. Preparations for a full-scale, 1764 pixel camera mechanics and a cooling system are ongoing. The paper describes the status of the project.

  8. Mastery of Status Epilepticus Management via Simulation-Based Learning for Pediatrics Residents

    PubMed Central

    Malakooti, Marcelo R.; McBride, Mary E.; Mobley, Bonnie; Goldstein, Joshua L.; Adler, Mark D.; McGaghie, William C.

    2015-01-01

    Background Management of status epilepticus (SE) in the pediatric population is highly time-sensitive. Failure to follow a standard management algorithm may be due to ineffective provider education, and can lead to unfavorable outcomes. Objective To design a learning module using high-fidelity simulation technology to teach mastery achievement of a hospital algorithm for managing SE. Methods Thirty pediatrics interns were enrolled. Using the Angoff method, an expert panel developed the minimal passing score, which defined mastery. Scoring of simulated performance was done by 2 observers. Sessions were digitally recorded. After the pretest, participants were debriefed on the algorithm and required to repeat the simulation. If mastery (minimal passing score) was not achieved, debriefing and the simulation were repeated until mastery was met. Once mastery was met, participants graded their comfort level in managing SE. Results No participants achieved mastery at pretest. After debriefing and deliberate simulator training, all (n = 30) achieved mastery of the algorithm: 30% achieved mastery after 1 posttest, 63% after a second, and 6.7% after a third. The Krippendorff α was 0.94, indicating strong interrater agreement. Participants reported more self-efficacy in managing SE, a preference for simulation-based education for learning practice-based algorithms of critical conditions, and highly rated the educational intervention. Conclusions A simulation-based mastery learning program using deliberate practice dramatically improves pediatrics residents' execution of a SE management protocol. Participants enjoyed and benefited from simulation education. Future applications include improving adherence to other hospital protocols. PMID:26221431

  9. Silencing Status Epilepticus-Induced BDNF Expression with Herpes Simplex Virus Type-1 Based Amplicon Vectors

    PubMed Central

    Falcicchia, Chiara; Trempat, Pascal; Binaschi, Anna; Perrier-Biollay, Coline; Roncon, Paolo; Soukupova, Marie; Berthommé, Hervé; Simonato, Michele

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) has been found to produce pro- but also anti-epileptic effects. Thus, its validity as a therapeutic target must be verified using advanced tools designed to block or to enhance its signal. The aim of this study was to develop tools to silence the BDNF signal. We generated Herpes simplex virus type 1 (HSV-1) derived amplicon vectors, i.e. viral particles containing a genome of 152 kb constituted of concatameric repetitions of an expression cassette, enabling the expression of the gene of interest in multiple copies. HSV-1 based amplicon vectors are non-pathogenic and have been successfully employed in the past for gene delivery into the brain of living animals. Therefore, amplicon vectors should represent a logical choice for expressing a silencing cassette, which, in multiple copies, is expected to lead to an efficient knock-down of the target gene expression. Here, we employed two amplicon-based BDNF silencing strategies. The first, antisense, has been chosen to target and degrade the cytoplasmic mRNA pool of BDNF, whereas the second, based on the convergent transcription technology, has been chosen to repress transcription at the BDNF gene. Both these amplicon vectors proved to be effective in down-regulating BDNF expression in vitro, in BDNF-expressing mesoangioblast cells. However, only the antisense strategy was effective in vivo, after inoculation in the hippocampus in a model of status epilepticus in which BDNF mRNA levels are strongly increased. Interestingly, the knocking down of BDNF levels induced with BDNF-antisense was sufficient to produce significant behavioral effects, in spite of the fact that it was produced only in a part of a single hippocampus. In conclusion, this study demonstrates a reliable effect of amplicon vectors in knocking down gene expression in vitro and in vivo. Therefore, this approach may find broad applications in neurobiological studies. PMID:26954758

  10. Silencing Status Epilepticus-Induced BDNF Expression with Herpes Simplex Virus Type-1 Based Amplicon Vectors.

    PubMed

    Falcicchia, Chiara; Trempat, Pascal; Binaschi, Anna; Perrier-Biollay, Coline; Roncon, Paolo; Soukupova, Marie; Berthommé, Hervé; Simonato, Michele

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) has been found to produce pro- but also anti-epileptic effects. Thus, its validity as a therapeutic target must be verified using advanced tools designed to block or to enhance its signal. The aim of this study was to develop tools to silence the BDNF signal. We generated Herpes simplex virus type 1 (HSV-1) derived amplicon vectors, i.e. viral particles containing a genome of 152 kb constituted of concatameric repetitions of an expression cassette, enabling the expression of the gene of interest in multiple copies. HSV-1 based amplicon vectors are non-pathogenic and have been successfully employed in the past for gene delivery into the brain of living animals. Therefore, amplicon vectors should represent a logical choice for expressing a silencing cassette, which, in multiple copies, is expected to lead to an efficient knock-down of the target gene expression. Here, we employed two amplicon-based BDNF silencing strategies. The first, antisense, has been chosen to target and degrade the cytoplasmic mRNA pool of BDNF, whereas the second, based on the convergent transcription technology, has been chosen to repress transcription at the BDNF gene. Both these amplicon vectors proved to be effective in down-regulating BDNF expression in vitro, in BDNF-expressing mesoangioblast cells. However, only the antisense strategy was effective in vivo, after inoculation in the hippocampus in a model of status epilepticus in which BDNF mRNA levels are strongly increased. Interestingly, the knocking down of BDNF levels induced with BDNF-antisense was sufficient to produce significant behavioral effects, in spite of the fact that it was produced only in a part of a single hippocampus. In conclusion, this study demonstrates a reliable effect of amplicon vectors in knocking down gene expression in vitro and in vivo. Therefore, this approach may find broad applications in neurobiological studies.

  11. Students' Understanding of Acid, Base and Salt Reactions in Qualitative Analysis.

    ERIC Educational Resources Information Center

    Tan, Kim-Chwee Daniel; Goh, Ngoh-Khang; Chia, Lian-Sai; Treagust, David F.

    2003-01-01

    Uses a two-tier, multiple-choice diagnostic instrument to determine (n=915) grade 10 students' understanding of the acid, base, and salt reactions involved in basic qualitative analysis. Reports that many students did not understand the formation of precipitates and the complex salts, acid/salt-base reactions, and thermal decomposition involved in…

  12. Collaborative Strategies for Teaching Common Acid-Base Disorders to Medical Students

    ERIC Educational Resources Information Center

    Petersen, Marie Warrer; Toksvang, Linea Natalie; Plovsing, Ronni R.; Berg, Ronan M. G.

    2014-01-01

    The ability to recognize and diagnose acid-base disorders is of the utmost importance in the clinical setting. However, it has been the experience of the authors that medical students often have difficulties learning the basic principles of acid-base physiology in the respiratory physiology curriculum, particularly when applying this knowledge to…

  13. The acid-base resistant zone in three dentin bonding systems.

    PubMed

    Inoue, Go; Nikaido, Toru; Foxton, Richard M; Tagami, Junji

    2009-11-01

    An acid-base resistant zone has been found to exist after acid-base challenge adjacent to the hybrid layer using SEM. The aim of this study was to examine the acid-base resistant zone using three different bonding systems. Dentin disks were applied with three different bonding systems, and then a resin composite was light-cured to make dentin disk sandwiches. After acid-base challenge, the polished surfaces were observed using SEM. For both one- and two-step self-etching primer systems, an acid-base resistant zone was clearly observed adjacent to the hybrid layer - but with differing appearances. For the wet bonding system, the presence of an acid-base resistant zone was unclear. This was because the self-etching primer systems etched the dentin surface mildly, such that the remaining mineral phase of dentin and the bonding agent yielded clear acid-base resistant zones. In conclusion, the acid-base resistant zone was clearly observed when self-etching primer systems were used, but not so for the wet bonding system.

  14. Mixed acid-base disorder secondary to topiramate use in traumatic brain injury

    PubMed Central

    Golla, S.; Anandh, U.; Balasubramaniam, A.

    2016-01-01

    We report a case of a man with traumatic brain injury. He was started on to prophylactic topiramate which led to a mixed acid-base disorder. He had severe metabolic acidosis secondary to renal tubular acidification defect and respiratory alkalosis secondary to hyperventilation. Withdrawal of the offending drug led to the prompt resolution of the acid-base disturbance. PMID:27942179

  15. Red Shoe-Blue Shoe: An Acid-Base Demonstration with a Fashionable Twist.

    ERIC Educational Resources Information Center

    Breyer, Arthur C.; Uzelmeier, Calvin E.

    1998-01-01

    Illustrates that acid-base indicators come in many forms and the reversible effects that acids and bases have on the colors of such indicators. An object is dyed in an indicator, which causes the object to turn dark blue at pH less than 3.0 to 5.0. Suggests using dyeable fabric shoes and other cotton articles. (PVD)

  16. Lewis Acid-Base, Molecular Modeling, and Isotopic Labeling in a Sophomore Inorganic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Nataro, Chip; Ferguson, Michelle A.; Bocage, Katherine M.; Hess, Brian J.; Ross, Vincent J.; Swarr, Daniel T.

    2004-01-01

    An experiment to prepare a deuterium labeled adduct of a Lewis acid and Lewis base, to use computational methods allowing students to visualize the LUMO of Lewis acids, the HOMO of Lewis bases and the molecular orbitals of the adduct that is formed is developed. This allows students to see the interplay between calculated and experimental results.

  17. Thai Grade 11 Students' Alternative Conceptions for Acid-Base Chemistry

    ERIC Educational Resources Information Center

    Artdej, Romklao; Ratanaroutai, Thasaneeya; Coll, Richard Kevin; Thongpanchang, Tienthong

    2010-01-01

    This study involved the development of a two-tier diagnostic instrument to assess Thai high school students' understanding of acid-base chemistry. The acid-base diagnostic test (ABDT) comprising 18 items was administered to 55 Grade 11 students in a science and mathematics programme during the second semester of the 2008 academic year. Analysis of…

  18. Using Conceptual Change Texts with Analogies for Misconceptions in Acids and Bases

    ERIC Educational Resources Information Center

    Cetingul, Ipek; Geban, Omer

    2011-01-01

    This study was conducted to explore the effectiveness of conceptual change oriented instruction over traditional instruction on students' understanding of acids and bases concept. Besides, effects of gender difference and science process skills on students' understanding of acids and bases were also investigated. Analysis of the results showed…

  19. Using the Logarithmic Concentration Diagram, Log "C", to Teach Acid-Base Equilibrium

    ERIC Educational Resources Information Center

    Kovac, Jeffrey

    2012-01-01

    Acid-base equilibrium is one of the most important and most challenging topics in a typical general chemistry course. This article introduces an alternative to the algebraic approach generally used in textbooks, the graphical log "C" method. Log "C" diagrams provide conceptual insight into the behavior of aqueous acid-base systems and allow…

  20. High School Students' Understanding of Acid-Base Concepts: An Ongoing Challenge for Teachers

    ERIC Educational Resources Information Center

    Damanhuri, Muhd Ibrahim Muhamad; Treagust, David F.; Won, Mihye; Chandrasegaran, A. L.

    2016-01-01

    Using a quantitative case study design, the "Acids-Bases Chemistry Achievement Test" ("ABCAT") was developed to evaluate the extent to which students in Malaysian secondary schools achieved the intended curriculum on acid-base concepts. Responses were obtained from 260 Form 5 (Grade 11) students from five schools to initially…

  1. A Comparative Study of French and Turkish Students' Ideas on Acid-Base Reactions

    ERIC Educational Resources Information Center

    Cokelez, Aytekin

    2010-01-01

    The goal of this comparative study was to determine the knowledge that French and Turkish upper secondary-school students (grades 11 and 12) acquire on the concept of acid-base reactions. Following an examination of the relevant curricula and textbooks in the two countries, 528 students answered six written questions about the acid-base concept.…

  2. Canonical Pedagogical Content Knowledge by Cores for Teaching Acid-Base Chemistry at High School

    ERIC Educational Resources Information Center

    Alvarado, Clara; Cañada, Florentina; Garritz, Andoni; Mellado, Vicente

    2015-01-01

    The topic of acid-base chemistry is one of the oldest in general chemistry courses and it has been almost continuously in academic discussion. The central purpose of documenting the knowledge and beliefs of a group of ten Mexican teachers with experience in teaching acid-base chemistry in high school was to know how they design, prepare and…

  3. Measuring the Confidence of 8th Grade Taiwanese Students' Knowledge of Acids and Bases

    ERIC Educational Resources Information Center

    Jack, Brady Michael; Liu, Chia-Ju; Chiu, Houn-Lin; Tsai, Chun-Yen

    2012-01-01

    The present study investigated whether gender differences were present on the confidence judgments made by 8th grade Taiwanese students on the accuracy of their responses to acid-base test items. A total of 147 (76 male, 71 female) students provided item-specific confidence judgments during a test of their knowledge of acids and bases. Using the…

  4. Effects of fatty acid activation on photosynthetic production of fatty acid-based biofuels in Synechocystis sp. PCC6803

    PubMed Central

    2012-01-01

    Background Direct conversion of solar energy and carbon dioxide to drop in fuel molecules in a single biological system can be achieved from fatty acid-based biofuels such as fatty alcohols and alkanes. These molecules have similar properties to fossil fuels but can be produced by photosynthetic cyanobacteria. Results Synechocystis sp. PCC6803 mutant strains containing either overexpression or deletion of the slr1609 gene, which encodes an acyl-ACP synthetase (AAS), have been constructed. The complete segregation and deletion in all mutant strains was confirmed by PCR analysis. Blocking fatty acid activation by deleting slr1609 gene in wild-type Synechocystis sp. PCC6803 led to a doubling of the amount of free fatty acids and a decrease of alkane production by up to 90 percent. Overexpression of slr1609 gene in the wild-type Synechocystis sp. PCC6803 had no effect on the production of either free fatty acids or alkanes. Overexpression or deletion of slr1609 gene in the Synechocystis sp. PCC6803 mutant strain with the capability of making fatty alcohols by genetically introducing fatty acyl-CoA reductase respectively enhanced or reduced fatty alcohol production by 60 percent. Conclusions Fatty acid activation functionalized by the slr1609 gene is metabolically crucial for biosynthesis of fatty acid derivatives in Synechocystis sp. PCC6803. It is necessary but not sufficient for efficient production of alkanes. Fatty alcohol production can be significantly improved by the overexpression of slr1609 gene. PMID:22433663

  5. Hyaluronic acid-based hydrogel enhances neuronal survival in spinal cord slice cultures from postnatal mice.

    PubMed

    Schizas, Nikos; Rojas, Ramiro; Kootala, Sujit; Andersson, Brittmarie; Pettersson, Jennie; Hilborn, Jons; Hailer, Nils P

    2014-02-01

    Numerous biomaterials based on extracellular matrix-components have been developed. It was our aim to investigate whether a hyaluronic acid-based hydrogel improves neuronal survival and tissue preservation in organotypic spinal cord slice cultures. Organotypic spinal cord slice cultures were cultured for 4 days in vitro (div), either on hyaluronic acid-based hydrogel (hyaluronic acid-gel group), collagen gel (collagen group), directly on polyethylene terephthalate membrane inserts (control group), or in the presence of soluble hyaluronic acid (soluble hyaluronic acid group). Cultures were immunohistochemically stained against neuronal antigen NeuN and analyzed by confocal laser scanning microscopy. Histochemistry for choline acetyltransferance, glial fibrillary acidic protein, and Griffonia simplicifolia isolectin B4 followed by quantitative analysis was performed to assess motorneurons and different glial populations. Confocal microscopic analysis showed a 4-fold increase in the number of NeuN-positive neurons in the hyaluronic acid-gel group compared to both collagen (p < 0.001) and control groups (p < 0.001). Compared to controls, organotypic spinal cord slice cultures maintained on hyaluronic acid-based hydrogel showed 5.9-fold increased survival of choline acetyltransferance-positive motorneurons (p = 0.008), 2-fold more numerous resting microglial cells in the white matter (p = 0.031), and a 61.4% reduction in the number of activated microglial cells within the grey matter (p = 0.05). Hyaluronic acid-based hydrogel had a shear modulus (G') of ≈1200 Pascals (Pa), which was considerably higher than the ≈25 Pa measured for collagen gel. Soluble hyaluronic acid failed to improve tissue preservation. In conclusion, hyaluronic acid-based hydrogel improves neuronal and - most notably - motorneuron survival in organotypic spinal cord slice cultures and microglial activation is limited. The positive effects of hyaluronic acid-based hydrogel

  6. Microbial Community Structure and Physiological Status of Different Types of Biofilms in an Acid Mine Drainage Site Determined by Phospholipid Analysis

    NASA Astrophysics Data System (ADS)

    Fang, J.

    2009-12-01

    A unique aspect of the acid mine drainage (AMD) system at the Green Valley coal mine site (GVS) in western Indiana is the abundance of biofims and biolaminates - stromatolites. Three major types of biofilms have been observed from the AMD site: bright green biofilm dominated by the acidophilic, oxygenic photosynthetic protozoan Euglena mutabilis, olive green biofilm of photosynthetic diatom belonging to the genus Nitzschia, and an olive-green to brownish-green filamentous algae-dominated community. These biofilms are either attached to hard substrata of the effluent channel, or floating at the surface of the effluent with abundant oxygen bubbles, with or without encrusted Fe precipitates. We analyzed lipids (hydrocarbons, wax esters, phospholipids, glycolipids, and neutral lipids) to determine the microbial biomass, community structure and physiological status of biofims collected from the GVS site. Distinctive lipid compositions were observed. The attached, red-crusted biofilms were characterized by abundant wax esters, monounsaturated fatty acids, whereas the floating biofilms by phytadienes, phytanol, polyunsaturated n-alkenes, polyunsaturated fatty acids. The accumulation of abundant wax esters probably reflects the readily available carbon and limitation of nutrients to the biofilm. Alternatively, the wax esters may be the biochemical relics of the anaerobic past of the Earth and the detection of these compounds has important implications for the evolution of eukaryotes and the paleo-environmental conditions on early Earth. This type of biochemical machine may have allowed early eukaryotes to survive recurrent anoxic conditions on early Earth.

  7. Synthesis and characterization of acetic acid and ethanoic acid (based)-maleimide

    NASA Astrophysics Data System (ADS)

    Poad, Siti Nashwa Mohd; Hassan, Nurul Izzaty; Hassan, Nur Hasyareeda

    2016-11-01

    A new route to the synthesis of maleimide is described. 2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)acetic acid maleimide (1) and 2-(4-(2,5-Dioxo-2,5-dihydro- 1H-pyrrol-1-yl)phenyl)ethanoic acid maleimide (2) have been synthesized by the reaction of maleic anhydride with glycine and 4-aminophenyl acetic aicd. Maleimide (1) was synthesized by conventional technique while maleimide (2) was synthesized by microwave method. The compounds were characterized using FT-Infrared (FT-IR), 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopies and Mass Spectrometry.

  8. Fatty acid synthesis in Escherichia coli and its applications towards the production of fatty acid based biofuels

    PubMed Central

    2014-01-01

    The idea of renewable and regenerative resources has inspired research for more than a hundred years. Ideally, the only spent energy will replenish itself, like plant material, sunlight, thermal energy or wind. Biodiesel or ethanol are examples, since their production relies mainly on plant material. However, it has become apparent that crop derived biofuels will not be sufficient to satisfy future energy demands. Thus, especially in the last decade a lot of research has focused on the production of next generation biofuels. A major subject of these investigations has been the microbial fatty acid biosynthesis with the aim to produce fatty acids or derivatives for substitution of diesel. As an industrially important organism and with the best studied microbial fatty acid biosynthesis, Escherichia coli has been chosen as producer in many of these studies and several reviews have been published in the fields of E. coli fatty acid biosynthesis or biofuels. However, most reviews discuss only one of these topics in detail, despite the fact, that a profound understanding of the involved enzymes and their regulation is necessary for efficient genetic engineering of the entire pathway. The first part of this review aims at summarizing the knowledge about fatty acid biosynthesis of E. coli and its regulation, and it provides the connection towards the production of fatty acids and related biofuels. The second part gives an overview about the achievements by genetic engineering of the fatty acid biosynthesis towards the production of next generation biofuels. Finally, the actual importance and potential of fatty acid-based biofuels will be discussed. PMID:24405789

  9. Status and progress of the novel photon detectors based on THGEM and hybrid MPGD architectures

    NASA Astrophysics Data System (ADS)

    Alexeev, M.; Birsa, R.; Bradamante, F.; Bressan, A.; Büchele, M.; Chiosso, M.; Ciliberti, P.; Dalla Torre, S.; Dasgupta, S.; Denisov, O.; Duic, V.; Finger, M.; Finger, M.; Fischer, H.; Giorgi, M.; Gobbo, B.; Gregori, M.; Herrmann, F.; Königsmann, K.; Levorato, S.; Maggiora, A.; Martin, A.; Menon, G.; Novakova, K.; Novy, J.; Panzieri, D.; Pereira, F. A.; Santos, C. A.; Sbrizzai, G.; Schiavon, P.; Schopferer, S.; Slunecka, M.; Sozzi, F.; Steiger, L.; Sulc, M.; Takekawa, S.; Tessarotto, F.; Veloso, J. F. C. A.

    2014-12-01

    We are developing large size THick GEM (THGEM)-based detectors of single photons, mainly meant for Cherenkov imaging applications. The R&D programme includes the complete characterisation of the THGEM electron multipliers, the study of the aspects related to the detection of single photons and the engineering towards large size detector prototypes. Our most recent achievements include dedicated studies concerning the ion backflow to the photocathode; relevant progress in the engineering aspects, in particularly related to the production of large-size THGEMs, where the strict correlation between the local gain-value and the local thickness-value has been demonstrated and a 300×300 mm2 active area detector has been successfully operated at the CERN PS T10 test beam; the introduction of a new hybrid detector architecture, offering promising performance, which is formed by a THGEM layer which acts both as photocathode and pre-amplification device, followed by a MICROMEGAS (MM) multiplication stage. We report about the general status of the R&D programme and, in detail, about the recent progress.

  10. Development of a portable spectroscopy-based device to detect nutrient status of apple tree

    NASA Astrophysics Data System (ADS)

    Zhang, Yao; Zheng, Lihua; Li, Minzan; Deng, Xiaolei; An, Xiaofei

    2012-11-01

    In order to detect apple tree growth status fast and accurately, four sensitive wavebands (364nm, 652nm, 766nm, 810nm) were obtained by analyzing the correlation between the apple leaves spectra and their nitrogen contents plus adopting the segment reduced precise sampling methods. A rapid determination model of apple leaf nitrogen content suitable for portable detector was built. Then a portable spectroscopy-based device was developed. It consists of an optical unit and a control unit. The optical channel was consisted of convex lens, optical filter, photoelectric detector and airtight mechanical exine. The optical unit was used to capture, transit, transform and submit the optical signal. The controller was consisted of operation, input, display, data storage and power control unit adopting JN5139 as main control unit. Controller was the coordinator in building the wireless network. And it was also responsible for receiving the measured data from sensor, calculating vegetation index, and displaying and storing the calculated results. The experiments showed that the correlation coefficient between the measured nitrogen content and the predicted nitrogen content reached to 0.857. It illustrated that the apple tree nitrogen detector was practical and could be used to detect leaf nitrogen content in apple orchard.

  11. Biorefinery approach for cassava-based industrial wastes: Current status and opportunities.

    PubMed

    Zhang, Ming; Xie, Li; Yin, Zhixuan; Khanal, Samir Kumar; Zhou, Qi

    2016-09-01

    Cassava, an important food crop, has been extensively employed as raw materials for various agri-industries to produce starch, bioethanol and other biobased products/chemicals. These cassava-based industries also generate large quantities of wastes/residues, rich in organic matter and suspended solids, and pose significant environmental issues. Their complex biochemical composition with high organic content endows them with a great potential for bioconversion into value-added products via biorefinery thereby providing economic and environmental sustainability to cassava industries. This state-of-the-art review covers the source, composition and characteristics of cassava industrial wastes and residues, and their bioconversion into value-added products, mainly biofuels (ethanol and butanol), biogas, biosurfactant, organic acids and other valuable biochemicals among others. This paper also outlines future perspectives with respect to developing more effective and efficient bioconversion processes for converting the cassava wastes and residues into high-value products.

  12. [Reaction of bone tissue elements on synthetic bioresorbable materials based on lactic and glycolic acids].

    PubMed

    Kulakov, A A; Grigor'ian, A S

    2014-01-01

    The aim of the study was to evaluate the adverse effects of synthetic polymeric bioresorbable materials based on lactic and glycolic acids on the bone tissue. The study was carried-out on 40 Wister-line rats. Four types of bioresorbable polymeric materials were implanted: PolyLactide Glycolide Acid (PLGA), Poly-L-Lactide Acid (PLLA); Poly-96L/4D-Lactide Acid (96/4 PLDLA); Poly-70L/30D-Lactide Acid (70/30 PLDLA). The results showed connective tissue formation (fibrointegration) bordering bone adjacent to implanted materials. This proved the materials to cause pathogenic influence on the bone which mechanisms are described in the article.

  13. PMK-S005 Alleviates Age-Related Gastric Acid Secretion, Inflammation, and Oxidative Status in the Rat Stomach

    PubMed Central

    Choi, Yoon Jeong; Kim, Nayoung; Lee, Ju Yup; Nam, Ryoung Hee; Suh, Ji Hyung; Lee, Sun Min; Ham, Min Hee; Jo, Hyun Jin; Shim, Young Kwang; Park, Yo Han; Lee, Jong-Chan; Choi, Yoon Jin; Lee, Hye Seung; Lee, Dong Ho

    2016-01-01

    Background/Aims The aim of this study was to evaluate the effect of the synthetic S-allyl-l-cysteine (SAC) PMK-S005 on gastric acid secretion, inflammation, and antioxidant enzymes in aging rats. Methods The rats were divided into four groups at 31 weeks of age and were continuously fed a diet containing a vehicle control, PMK-S005 (5 or 10 mg/kg), or lansoprazole (5 mg/kg). Gastric acid secretion and connective tissue thickness of the lamina propria were evaluated at 74 weeks and 2 years of age. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and COX-2 levels were measured by using enzyme-linked immunosorbent assays (ELISAs) or Western blot assays. Levels of antioxidant enzymes, including heme oxyganase 1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1), were also measured. Results As the rats aged, gastric acid secretion significantly decreased, and the connective tissue of the lamina propria increased. However, 74-week-old rats in the PMK-S005 group exhibited greater levels of gastric acid secretion than those of the control and lansoprazole groups. The increase of TNF-α, IL-1β, and COX-2 expression in 74-week and 2-year-old control rats were inhibited by PMK-S005. In addition, the decrease in HO-1 and NQO-1 protein expression that occurred with aging was inhibited by PMK-S005 in the 74-week-old rats. Conclusions These results suggest that PMK-S005 has therapeutic potential as an antiaging agent to ameliorate age-related gastric acid secretion, inflammation, and oxidative stress in the stomach. PMID:27172930

  14. Nutritional status of urban adolescents: individual, household and neighborhood factors based on data from The BH Health Study.

    PubMed

    Bispo, Stephanie; Correia, Maria Isabel Toulson Davisson; Proietti, Fernando Augusto; Xavier, César Coelho; Caiaffa, Waleska Teixeira

    2015-11-01

    The increasing prevalence of overweight in young people suggests that adolescent nutritional status is influenced by environmental factors. Using hierarchical modelling, this study aimed to analyse the association between individual, household and neighborhood factors and adolescent nutritional status and well-being. The study used data from a population-based household survey conducted in Belo Horizonte, the capital of the State of Minas Gerais, Brazil, between 2008 and 2009. Data was obtained from an adult and adolescent in each household using a confidential questionnaire and anthropometric measurements. Adolescent nutritional status was evaluated using multinomial regression analysis considering distal and proximal influences. The prevalence of overweight and thinness among the sample of 1,030 adolescents was 21.9% and 4.6%, respectively. Although variables from all blocks remained in the final model, head of household education level, family habits and family nutritional status were shown to strongly influence adolescent nutritional status. New approaches to public health are needed which focus on raising awareness and promoting health education targeting teenagers and their social context.

  15. Development of a molecular-based index for assessing iron status in bloom-forming pennate diatoms.

    PubMed

    Marchetti, Adrian; Moreno, Carly M; Cohen, Natalie R; Oleinikov, Irina; deLong, Kimberly; Twining, Benjamin S; Armbrust, Virginia E; Lampe, Robert H

    2017-04-10

    Iron availability limits primary productivity in large areas of the world's oceans. Ascertaining the iron status of phytoplankton is essential for understanding the factors regulating their growth and ecology. We developed an incubation-independent, molecular-based approach to assess the iron nutritional status of specific members of the diatom community, initially focusing on the ecologically important pennate diatom Pseudo-nitzschia. Through a comparative transcriptomic approach, we identified two genes that track the iron status of Pseudo-nitzschia with high fidelity. The first gene, FTN, encodes for the highly specialized iron storage protein ferritin. The second gene, ISIP2a, encodes an iron-concentrating protein induced under iron-limiting conditions. In the oceanic diatom Pseudo-nitzschia granii (Hasle) Hasle, transcript abundance of these genes directly relates to changes in iron availability, with increased FTN transcript abundance under iron-replete conditions and increased ISIP2a transcript abundance under iron-limiting conditions. The resulting ISIP2a:FTN transcript ratio reflects the iron status of cells, where a high ratio indicates iron limitation. Field samples collected from iron grow-out microcosm experiments conducted in low iron waters of the Gulf of Alaska and variable iron waters in the California Upwelling Zone verify the validity of our proposed Pseudo-nitzschia Iron Limitation Index (ILI), which can be used to ascertain in situ iron status and further developed for other ecologically important diatoms. This article is protected by copyright. All rights reserved.

  16. Cross-linked, biodegradable, cytocompatible salicylic acid based polyesters for localized, sustained delivery of salicylic acid: an in vitro study.

    PubMed

    Chandorkar, Yashoda; Bhagat, Rajesh K; Madras, Giridhar; Basu, Bikramjit

    2014-03-10

    In order to suppress chronic inflammation while supporting cell proliferation, there has been a continuous surge toward development of polymers with the intention of delivering anti-inflammatory molecules in a sustained manner. In the above backdrop, we report the synthesis of a novel, stable, cross-linked polyester with salicylic acid (SA) incorporated in the polymeric backbone and propose a simple synthesis route by melt condensation. The as-synthesized polymer was hydrophobic with a glass transition temperature of 1 °C, which increases to 17 °C upon curing. The combination of NMR and FT-IR spectral techniques established the ester linkages in the as-synthesized SA-based polyester. The pH-dependent degradation rate and the rate of release of salicylic acid from the as-synthesized SA-based polymer were studied at physiological conditions in vitro. The polyester underwent surface erosion and exhibited linear degradation kinetics in which a change in degradation rate is observed after 4-10 days and 24% mass loss was recorded after 4 months at 37 °C and pH 7.4. The delivery of salicylic acid also showed a similar change in slopes, with a sustained release rate of 3.5% in 4 months. The cytocompatibility studies of these polyesters were carried out with C2C12 murine myoblast cells using techniques like MTT assay and flow cytometry. Our results strongly suggest that SA-based polyester supports cell proliferation for 3 days in culture and do not cause cell death (<7%), as quantified by propidium iodide (PI) stained cells. Hence, these polyesters can be used as implant materials for localized, sustained delivery of salicylic acid and have applications in adjuvant cancer therapy, chronic wound healing, and as an alternative to commercially available polymers like poly(lactic acid) and poly(glycolic acid) or their copolymers.

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

    PubMed

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

    2016-04-11

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

  18. A novel enzyme-based acidizing system: Matrix acidizing and drilling fluid damage removal

    SciTech Connect

    Harris, R.E.; McKay, D.M.; Moses, V.

    1995-12-31

    A novel acidizing process is used to increase the permeability of carbonate rock cores in the laboratory and to remove drilling fluid damage from cores and wafers. Field results show the benefits of the technology as applied both to injector and producer wells.

  19. Investigations of the pore formation in the lead selenide films using glacial acetic acid- and nitric acid-based electrolyte

    PubMed Central

    2012-01-01

    We report a novel synthesis of porous PbSe layers on Si substrates by anodic electrochemical treatment of PbSe/CaF2/Si(111) epitaxial structures in an electrolyte solution based on glacial acetic acid and nitric acid. Electron microscopy, X-ray diffractometry, and local chemical microanalysis investigation results for the porous layers are presented. Average size of the synthesized mesopores with approximately 1010 cm−2 surface density was determined to be 22 nm. The observed phenomenon of the active selenium redeposition on the mesopore walls during anodic treatment is discussed. PMID:22726822

  20. Investigations of the pore formation in the lead selenide films using glacial acetic acid- and nitric acid-based electrolyte.

    PubMed

    Zimin, Sergey P; Gorlachev, Egor S; Naumov, Viktor V; Skok, Fedor O

    2012-01-01

    We report a novel synthesis of porous PbSe layers on Si substrates using anodic electrochemical treatment of PbSe/CaF2/Si(111) epitaxial structures in an electrolyte solution based on glacial acetic acid and nitric acid. Electron microscopy, x-ray diffractometry, and local chemical microanalysis investigations results for the porous layers are presented. Average size of the synthesized mesopores with ~1010 cm-2 surface density was determined to be 22 nm. The observed phenomenon of the active selenium redeposition on the mesopore walls during anodic treatment is discussed.

  1. Efficient voltammetric discrimination of free bilirubin from uric acid and ascorbic acid by a CVD nanographite-based microelectrode.

    PubMed

    Taurino, Irene; Van Hoof, Viviane; Magrez, Arnaud; Forró, László; De Micheli, Giovanni; Carrara, Sandro

    2014-12-01

    We report a novel electrochemical sensor based on nanographite grown on platinum microelectrodes for the determination of bilirubin in the presence of normal concentrations of albumin. The albumin is a protein with an intrinsic ability to bind the bilirubin therefore reducing the concentration of the free electroactive metabolite in human fluids. In addition, the proposed device permits the discrimination of free bilirubin from two interferents, uric acid and ascorbic acid, by the separation of their oxidation peaks in voltammetry. Preliminary measurements in human serum prove that the proposed nanostructured platform can be used to detect bilirubin.

  2. A Village-Based Intervention: Promoting Folic Acid Use among Rural Chinese Women

    PubMed Central

    Lin, Qian; Yang, Lina; Li, Fang; Qin, Hong; Li, Mingzhi; Chen, Jihua; Deng, Jing; Hu, Xiangying

    2017-01-01

    Background: Folic acid supplementation is effective in reducing the risk of neural tube defects (NTDs). However, the use of folic acid is low among rural women in China. Nutrition education can provide information about folic acid and encourage its use. The primary objective of this study was to test the effectiveness of a village-based nutrition intervention on folic acid use among rural women. Methods: Sixty villages were randomly selected using multiple-stage sampling and were divided into control and intervention groups. The intervention included nutritional education at village clinics, written materials, and text messages (SMS). Folic acid use knowledge and behavior was assessed at baseline and after the intervention. Results: Self-reported compliance with folic acid supplement use increased from 17.0%–29.2% at baseline to 41.7%–59.2% one year post-intervention. During the same period, the folic acid knowledge score in the intervention group increased from 3.07 to 3.65, significantly higher than the control group (3.11 to 3.35). Multivariate binary logistic regression showed that the women who received folic acid education and SMS intervention were more likely to comply with folic acid supplement recommendations. Conclusions: The results indicated that an integrated village-based folic acid education intervention may be an effective way of promoting folic acid use for the prevention of NTDs in rural women. PMID:28230798

  3. Bifunctional Organic Polymeric Catalysts with a Tunable Acid-Base Distance and Framework Flexibility

    PubMed Central

    Chen, Huanhui; Wang, Yanan; Wang, Qunlong; Li, Junhui; Yang, Shiqi; Zhu, Zhirong

    2014-01-01

    Acid-base bifunctional organic polymeric catalysts were synthesized with tunable structures. we demonstrated two synthesis approaches for structural fine-tune. In the first case, the framework flexibility was tuned by changing the ratio of rigid blocks to flexible blocks within the polymer framework. In the second case, we precisely adjusted the acid-base distance by distributing basic monomers to be adjacent to acidic monomers, and by changing the chain length of acidic monomers. In a standard test reaction for the aldol condensation of 4-nitrobenzaldehyde with acetone, the catalysts showed good reusability upon recycling and maintained relatively high conversion percentage. PMID:25267260

  4. Separation of thorium and uranium in nitric acid solution using silica based anion exchange resin.

    PubMed

    Chen, Yanliang; Wei, Yuezhou; He, Linfeng; Tang, Fangdong

    2016-09-30

    To separate thorium and uranium in nitric acid solution using anion exchange process, a strong base silica-based anion exchange resin (SiPyR-N4) was synthesized. Batch experiments were conducted and the separation factor of thorium and uranium in 9M nitric acid was about 10. Ion exchange chromatography was applied to separate thorium and uranium in different ratios. Uranium could be eluted by 9M nitric acid and thorium was eluted by 0.1M nitric acid. It was proved that thorium and uranium can be separated and recovered successfully by this method.

  5. Status, emotional displays, and the relationally-based evaluation of criminals and their behavior.

    PubMed

    Dilks, Lisa M; McGrimmon, Tucker S; Thye, Shane R

    2015-03-01

    This research uses status characteristics theory to expand our knowledge of the effects of status variables (e.g., race, education) and emotional displays on the antecedents of sentencing - evaluations of offender dangerousness and offense seriousness. We present a theoretical formulation that combines three areas of status characteristics research - reward expectations, individual evaluative settings and valued personal characteristics. The result is a quantitative measure that aggregates relative differences in demographic and emotional characteristics between offenders and their victims. The significance of this expectation advantage measure (e) in predicting evaluations of offender dangerousness and offense severity is tested using data from a vignette study. We find empirical support that expectation advantage significantly predicts these sentencing antecedents but not sentencing outcomes directly. We conclude by discussing the implications of our findings for future status and criminological research.

  6. Positive impact of a weekly iron-folic acid supplement delivered with social marketing to Cambodian women: compliance, participation, and hemoglobin levels increase with higher socioeconomic status.

    PubMed

    Crape, Byron L; Kenefick, Eric; Cavalli-Sforza, Tommaso; Busch-Hallen, Jennifer; Milani, Silvano; Kanal, Koum

    2005-12-01

    A social marketing program promoting weekly iron-folic acid supplementation improved hemoglobin levels in women of reproductive age in Cambodia. Supplementation was increasingly effective among women of higher socioeconomic status (SES). Among higher SES schoolgirls, 58% took the supplements, compared with 49% for lower SES (P = 0.07). Garment factory workers with an 11th- or 12th-grade education had a mean improvement in hemoglobin of 0.72 g/dL over those with a 5th-grade education or less (P = 0.04). The percentage of rural village women taking supplements increased with increasing SES (linear trend P = 0.046). These results suggest that women with lower SES be given special attention for future programs.

  7. Key volatile aroma compounds of lactic acid fermented malt based beverages - impact of lactic acid bacteria strains.

    PubMed

    Nsogning Dongmo, Sorelle; Sacher, Bertram; Kollmannsberger, Hubert; Becker, Thomas

    2017-08-15

    This study aims to define the aroma composition and key aroma compounds of barley malt wort beverages produced from fermentation using six lactic acid bacteria (LAB) strains. Gas chromatography mass spectrometry-olfactometry and flame ionization detection was employed; key aroma compounds were determined by means of aroma extract dilution analysis. Fifty-six detected volatile compounds were similar among beverages. However, significant differences were observed in the concentration of individual compounds. Key aroma compounds (flavor dilution (FD) factors ≥16) were β-damascenone, furaneol, phenylacetic acid, 2-phenylethanol, 4-vinylguaiacol, sotolon, methional, vanillin, acetic acid, nor-furaneol, guaiacol and ethyl 2-methylbutanoate. Furthermore, acetaldehyde had the greatest odor activity value of up to 4266. Sensory analyses revealed large differences in the flavor profile. Beverage from L. plantarum Lp. 758 showed the highest FD factors in key aroma compounds and was correlated to fruity flavors. Therefore, we suggest that suitable LAB strain selection may improve the flavor of malt based beverages.

  8. Effectiveness of methylcobalamin and folinic Acid treatment on adaptive behavior in children with autistic disorder is related to glutathione redox status.

    PubMed

    Frye, Richard E; Melnyk, Stepan; Fuchs, George; Reid, Tyra; Jernigan, Stefanie; Pavliv, Oleksandra; Hubanks, Amanda; Gaylor, David W; Walters, Laura; James, S Jill

    2013-01-01

    Treatments targeting metabolic abnormalities in children with autism are limited. Previously we reported that a nutritional treatment significantly improved glutathione metabolism in children with autistic disorder. In this study we evaluated changes in adaptive behaviors in this cohort and determined whether such changes are related to changes in glutathione metabolism. Thirty-seven children diagnosed with autistic disorder and abnormal glutathione and methylation metabolism were treated with twice weekly 75 µg/Kg methylcobalamin and twice daily 400 µg folinic acid for 3 months in an open-label fashion. The Vineland Adaptive Behavior Scale (VABS) and glutathione redox metabolites were measured at baseline and at the end of the treatment period. Over the treatment period, all VABS subscales significantly improved with an average effect size of 0.59, and an average improvement in skills of 7.7 months. A greater improvement in glutathione redox status was associated with a greater improvement in expressive communication, personal and domestic daily living skills, and interpersonal, play-leisure, and coping social skills. Age, gender, and history of regression did not influence treatment response. The significant behavioral improvements observed and the relationship between these improvements to glutathione redox status suggest that nutritional interventions targeting redox metabolism may benefit some children with autism.

  9. Periconceptional folic acid supplementation and vitamin B12 status in a cohort of Chinese early pregnancy women with the risk of adverse pregnancy outcomes

    PubMed Central

    Yang, Ting; Gu, Yan; Wei, Xiaoping; Liang, Xiaohua; Chen, Jie; Liu, Youxue; Zhang, Ting; Li, Tingyu

    2017-01-01

    Maternal folate and vitamin B12 deficiency predict poor pregnancy outcome. To improve pregnancy outcomes in rural area of China, we investigate rural women’s folic acid supplementation (FAS) status and the associations between maternal vitamin B status during the first trimester and subsequent adverse pregnancy outcomes. We collected the questionnaire information and drew 5 ml of blood from 309 early pregnant rural women. The birth outcomes were retrieved from medical records after delivery. Out of the total, 257 had taken FAS, including 50 before conception (group A) and 207 during the first trimester (group B). The concentration of plasma folate and the RBC folate supplementation groups were obviously higher than that of no-supplementation group (group N, p<0.01). The mean vitamin B12 levels in FAS group were significantly higher than those in groups N and B (p<0.05). Women who delivered SGA or premature infants had reduced plasma folate levels (p<0.05) compared with controls. The multiple linear regression models revealed that RBC folate levels affected the infant birth weight (p<0.01) and birth length (p<0.05). In conclusion, FAS can significantly improve plasma folate and RBC folate levels in childbearing-age women and reduce the risk of subsequent adverse pregnancy outcomes. PMID:28366994

  10. Improvement of ruthenium based decarboxylation of carboxylic acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The removal of oxygen atoms from biobased carboxylic acids is an attractive route to provide the drop in replacement feedstocks that industry needs to continue to provide high performance products. Through the use of ruthenium catalysis, an efficient method where this process can be accomplished on ...

  11. A new boronic acid based fluorescent reporter for catechol.

    PubMed

    Wu, Zhongyu; Li, Minyong; Fang, Hao; Wang, Binghe

    2012-12-01

    Catechol skeleton widely exists in natural products and bioactive substances. Fluorescent reporters which could recognize catechol are very promising for the construction of chemosensors to detect catechol and its derivatives in biological environment. Herein, we reported a novel catechol reporter, 2-(4-boronophenyl)quinoline-4-carboxylic acid, which exhibits significant fluorescent property changes upon binding catechol containing molecules in an aqueous solution.

  12. Enzymatic saccharification coupling with polyester recovery from cotton-based waste textiles by phosphoric acid pretreatment.

    PubMed

    Shen, Fei; Xiao, Wenxiong; Lin, Lili; Yang, Gang; Zhang, Yanzong; Deng, Shihuai

    2013-02-01

    In order to recycle the cotton-based waste textiles, a novel process was designed for pretreating waste textiles with phosphoric acid to recover polyester and fermentable sugar. The effects of pretreatment conditions including, phosphoric acid concentration, pretreatment temperature, time, and ratio of textiles and phosphoric acid were thoroughly investigated. Results indicated the mentioned four factors had significant influences on sugar and polyester recovery. Almost complete polyester recovery was achieved by enhancing phosphoric acid concentration, temperature and pretreatment time or reducing the ratio of textiles and phosphoric acid. However, these behaviors decreased the sugar recovery seriously. 100% polyester recovery with a maximum sugar recovery of 79.2% was achieved at the optimized conditions (85% phosphoric acid, 50°C, 7h, and the ratio of 1:15). According to the technical and cost-benefit analysis, it was technically feasible and potentially profitable to recover polyester and sugar from waste textiles by phosphoric acid pretreatment.

  13. Adsorption of Amino Acids and Glutamic Acid-Based Surfactants on Imogolite Clays.

    PubMed

    Bonini, Massimo; Gabbani, Alessio; Del Buffa, Stefano; Ridi, Francesca; Baglioni, Piero; Bordes, Romain; Holmberg, Krister

    2017-03-07

    Aluminum oxide surfaces are of utmost interest in different biotech applications, in particular for their use as adjuvants (i.e., booster of the immune response against infectious agents in vaccines production). In this framework, imogolite clays combine the chemical flexibility of an exposed alumina surface with 1D nanostructure. This work reports on the interaction between amino acids and imogolite, using turbidimetry, ζ-potential measurements, and Fourier transform infrared spectroscopy as main characterization tools. Amino acids with different side chain functional groups were investigated, showing that glutamic acid (Glu) has the strongest affinity for the imogolite surface. This was exploited to prepare a composite material made of a synthetic surfactant bearing a Glu polar head and a hydrophobic C12 alkyl tail, adsorbed onto the surface of imogolite. The adsorption of a model drug (rhodamine B isothiocyanate) by the hybrid was evaluated both in water and in physiological saline conditions. The findings of this paper suggest that the combination between the glutamate headgroup and imogolite represents a promising platform for the fabrication of hybrid nanostructures with tailored functionalities.

  14. A 19-base pair deletion polymorphism in dihydrofolate reductase is associated with increased unmetabolized folic acid in plasma and decreased red blood cell folate.

    PubMed

    Kalmbach, Renee D; Choumenkovitch, Silvina F; Troen, Aron P; Jacques, Paul F; D'Agostino, Ralph; Selhub, Jacob

    2008-12-01

    Dihydrofolate reductase (DHFR) catalyzes the reduction of folic acid to tetrahydrofolate (THF). A 19-bp noncoding deletion allele maps to intron 1, beginning 60 bases from the splice donor site, and has been implicated in neural tube defects and cancer, presumably by influencing folate metabolism. The functional impact of this polymorphism has not yet been demonstrated. The objective of this research was to determine the effects of the DHFR mutation with respect to folate status and assess influence of folic acid intake on these relations. The relationship between DHFR genotype and plasma concentrations of circulating folic acid, total folate, total homocysteine, and concentrations of RBC folate was determined in 1215 subjects from the Framingham Offspring Study. There was a significant interaction between DHFR genotype and folic acid intake with respect to the prevalence of high circulating unmetabolized folic acid (defined as >85th percentile). Folic acid intake of >or=500 microg/d increased the prevalence of high circulating unmetabolized folic acid in subjects with the deletion (del/del genotype (47.0%) compared with the wild type (WT)/del (21.4%) and wild type (WT)/WT genotypes (24.4%) (P for interaction = 0.03). Interaction between the DHFR polymorphism and folic acid intake was also seen with respect to RBC folate (P for interaction = 0.01). When folic acid intake was <250 microg/d, the del/del genotype was associated with significantly lower RBC folate (732.3 nmol/L) compared with the WT/WT genotype (844.4 nmol/L). Our results suggest the del/del polymorphism in DHFR is a functional polymorphism, because it limits assimilation of folic acid into cellular folate stores at high and low folic acid intakes.

  15. NPDES Permit Status Reports

    EPA Pesticide Factsheets

    These reports show the backlog status nationwide, based on EPA databases and input from EPA regions and states. The reports show a snapshot in time, keep in mind that the status of facilities and the universe of permits change.

  16. Folate contents in human milk and casein-based and soya-based formulas, and folate status in Korean infants.

    PubMed

    Han, Young-Hee; Yon, Miyong; Han, Heon-Seok; Kim, Kwang-Yup; Tamura, Tsunenobu; Hyun, Taisun H

    2009-06-01

    We assessed folate nutritional status from birth to 12 months in fifty-one infants who were fed human milk (HM; n 20), casein-based formula (CBF; n 12) or soya-based formula (SBF; n 19). Folate contents in ninety-five HM samples obtained from twenty mothers for the first 6-month period and twelve CBF and nineteen SBF samples were measured by bioassay after trienzyme extraction. Folate intake was estimated by weighing infants before and after feeding in the HM group and by collecting formula intake records in the formula-fed groups. After solid foods were introduced, all foods consumed were included to estimate folate intake. Serum folate and total homocysteine (tHcy) concentrations were determined at 5 and 12 months of age, and infant growth was monitored for the first 12 months. Mean HM folate contents ranged from 201 to 365 nmol/l with an overall mean of 291 nmol/l, and the contents peaked at 2 months postpartum. HM folate contents were higher than those reported in North America. Folate contents in CBF and SBF were markedly higher than those in HM and those claimed on the product labels. The overall folate intakes in formula-fed infants were significantly higher than those in HM-fed infants, and this was associated with significantly higher folate and lower tHcy in formula-fed infants than HM-fed infants at 5 months. At 12 months, serum folate was significantly higher in the SBF group than the other groups, whereas serum tHcy and overall growth were similar among all groups.

  17. The status of lightweight photovoltaic space array technology based on amorphous silicon solar cells

    NASA Technical Reports Server (NTRS)

    Hanak, Joseph J.; Kaschmitter, Jim

    1991-01-01

    Ultralight, flexible photovoltaic (PV) array of amorphous silicon (a-Si) was identified as a potential low cost power source for small satellites. A survey was conducted of the status of the a-Si PV array technology with respect to present and future performance, availability, cost, and risks. For existing, experimental array blankets made of commercial cell material, utilizing metal foil substrates, the Beginning of Life (BOL) performance at Air Mass Zero (AM0) and 35 C includes total power up to 200 W, power per area of 64 W/sq m and power per weight of 258 W/kg. Doubling of power per weight occurs when polyimide substrates are used. Estimated End of Life (EOL) power output after 10 years in a nominal low earth orbit would be 80 pct. of BOL, the degradation being due to largely light induced effects (-10 to -15 pct.) and in part (-5 pct.) to space radiation. Predictions for the year 1995 for flexible PV arrays, made on the basis of published results for rigid a-Si modules, indicate EOL power output per area and per weight of 105 W/sq m and 400 W/kg, respectively, while predictions for the late 1990s based on existing U.S. national PV program goals indicate EOL values of 157 W/sq m and 600 W/kg. Cost estimates by vendors for 200 W ultralight arrays in volume of over 1000 units range from $100/watt to $125/watt. Identified risks include the lack of flexible, space compatible encapsulant, the lack of space qualification effort, recent partial or full acquisitions of US manufacturers of a-Si cells by foreign firms, and the absence of a national commitment for a long range development program toward developing of this important power source for space.

  18. Influence of pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt.

    PubMed

    Akbaridoust, Ghazal; Plozza, Tim; Trenerry, V Craige; Wales, William J; Auldist, Martin J; Ajlouni, Said

    2015-08-01

    The influence of different pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt was studied. Pasture is the main source of nutrients for dairy cows in many parts of the world, including southeast Australia. Milk and milk products produced in these systems are known to contain a number of compounds with positive effects on human health. In the current study, 260 cows were fed supplementary grain and forage according to one of 3 different systems; Control (a traditional pasture based diet offered to the cows during milking and in paddock), PMR1 (a partial mixed ration which contained the same supplement as Control but was offered to the cows as a partial mixed ration on a feedpad), PMR 2 (a differently formulated partial mixed ration compared to Control and PMR1 which was offered to the cows on a feedpad). Most of the yoghurt fatty acids were influenced by feeding systems; however, those effects were minor on organic acids. The differences in feeding systems did not lead to the formation of different volatile organic flavour compounds in yoghurt. Yet, it did influence the relative abundance of these components.

  19. Synergistic effects on enantioselectivity of zwitterionic chiral stationary phases for separations of chiral acids, bases, and amino acids by HPLC.

    PubMed

    Hoffmann, Christian V; Pell, Reinhard; Lämmerhofer, Michael; Lindner, Wolfgang

    2008-11-15

    In an attempt to overcome the limited applicability scope of earlier proposed Cinchona alkaloid-based chiral weak anion exchangers (WAX) and recently reported aminosulfonic acid-based chiral strong cation exchangers (SCX), which are conceptionally restricted to oppositely charged solutes, their individual chiral selector (SO) subunits have been fused in a combinatorial synthesis approach into single, now zwitterionic, chiral SO motifs. The corresponding zwitterionic ion-exchange-type chiral stationary phases (CSPs) in fact combined the applicability spectra of the parent chiral ion exchangers allowing for enantioseparations of chiral acids and amine-type solutes in liquid chromatography using polar organic mode with largely rivaling separation factors as compared to the parent WAX and SCX CSPs. Furthermore, the application spectrum could be remarkably expanded to various zwitterionic analytes such as alpha- and beta-amino acids and peptides. A set of structurally related yet different CSPs consisting of either a quinine or quinidine alkaloid moiety as anion-exchange subunit and various chiral or achiral amino acids as cation-exchange subunits enabled us to derive structure-enantioselectivity relationships, which clearly provided strong unequivocal evidence for synergistic effects of the two oppositely charged ion-exchange subunits being involved in molecular recognition of zwitterionic analytes by zwitterionic SOs driven by double ionic coordination.

  20. Effects of Graded Levels of Chromium Methionine on Performance, Carcass Traits, Meat Quality, Fatty Acid Profiles of Fat, Tissue Chromium Concentrations, and Antioxidant Status in Growing-Finishing Pigs.

    PubMed

    Tian, Yao-Yao; Gong, Li-Min; Xue, Jian-Xiang; Cao, Jun; Zhang, Li-Ying

    2015-11-01

    A 97-day feeding trial was conducted to investigate the effects of dietary chromium methionine (CrMet) on performance, carcass traits, meat quality, fatty acid profiles of fat, tissue chromium concentrations, and antioxidant status in growing-finishing pigs. A total of 180 crossbred pigs with a mean initial body weight (BW) 30.18 ± 0.28 kg were allotted to 5 treatments with 6 replicates per treatment and 6 pigs per pen in a randomized complete block design based on BW and sex. Treatments were added with 0 (control), 100, 200, 400, and 800 μg/kg chromium as CrMet. Blood samples were obtained from the anterior vena cava on days 97. Carcass characteristics, pork quality, and tissue chromium concentration data were collected from one pig per pen. The results indicated that supplemental CrMet did not significantly affect growth performance, carcass traits, or meat amino acid profiles. Chromium at 100, 400, and 800 μg/kg decreased drip loss but increased shear force (P < 0.05). Pigs fed 100 or 400 μg/kg had a higher 24-h pH than the control (P < 0.05). While meat color, muscle moisture, crude protein, or crude fat were not affected by CrMet. Supplemental 800 μg/kg chromium reduced C18:0 levels in belly fat (P < 0.05), and chromium supplementation increased cis-9, trans 11-conjugated linoleic acid levels linearly (P < 0.05). Dietary CrMet supplementation increased serum, kidney, and muscle chromium contents (P < 0.05) but did not affect liver chromium contents. Besides, tissue chromium concentrations were increased linearly with increased chromium dosage (P < 0.05). Chromium at 400 μg/kg increased serum glutathione peroxidase activities (P < 0.05), and chromium at 800 μg/kg decreased serum total antioxidant capacity levels (P < 0.05). Nevertheless, liver and kidney antioxidant status were not significantly affected by CrMet. These results indicated that dietary supplementation CrMet did not significantly influence growth