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Sample records for acid-base balance

  1. Hypokalemic paralysis and acid-base balance

    Ivo Casagranda

    2006-10-01

    Full Text Available Three cases of hypokalemic paralysis are reported, presenting to the Emergency Department. The first is a patient with a hypokalemic periodic paralysis with a normal acid-base status, the second is a case of hypokalemic flaccid paralysis of all extremities with a normal anion gap metabolic acidosis, the last is a patient with a hypokalemic distal paralysis of right upper arm with metabolic alkalosis. Afterwards some pathophysiologic principles and the clinical aspects of hypokalemia are discussed and an appropriate approach to do in Emergency Department, to identify the hypokalemic paralysis etiologies in the Emergency Department, is presented, beginning from the evaluation of acid-base status.

  2. Hypokalemic paralysis and acid-base balance

    Ivo Casagranda; Riccardo Boverio; Andrea Defrancisci; Sara Ferrillo; Francesca Gargiulo

    2006-01-01

    Three cases of hypokalemic paralysis are reported, presenting to the Emergency Department. The first is a patient with a hypokalemic periodic paralysis with a normal acid-base status, the second is a case of hypokalemic flaccid paralysis of all extremities with a normal anion gap metabolic acidosis, the last is a patient with a hypokalemic distal paralysis of right upper arm with metabolic alkalosis. Afterwards some pathophysiologic principles and the clinical aspects of hypokalemia are discu...

  3. A REVIEW ON ACID BASE STATUS IN DAIRY COWS: IMPLICATIONS OF DIETARY CATION-ANION BALANCE

    D. Afzaal, M. Nisa, M. A. Khan and M. Sarwar

    2004-01-01

    The acid base status of a dairy cow is maintained within a narrow range. The key mechanisms involving blood, cells and lungs, perform this function. Although other minerals have an impact on acid base metabolism, the minerals used in dietary cation-anion balance (DCAB) namely sodium (Na), potassium (K) and chloride (Cl) have the greatest effect. Hence, acid base status implicates other biological functions of dairy cows. Low DCAB prepartum reduces the incidence of milk fever and increases the...

  4. A REVIEW ON ACID BASE STATUS IN DAIRY COWS: IMPLICATIONS OF DIETARY CATION-ANION BALANCE

    D. Afzaal, M. Nisa, M. A. Khan and M. Sarwar

    2004-10-01

    Full Text Available The acid base status of a dairy cow is maintained within a narrow range. The key mechanisms involving blood, cells and lungs, perform this function. Although other minerals have an impact on acid base metabolism, the minerals used in dietary cation-anion balance (DCAB namely sodium (Na, potassium (K and chloride (Cl have the greatest effect. Hence, acid base status implicates other biological functions of dairy cows. Low DCAB prepartum reduces the incidence of milk fever and increases the productivity by simmering down the severity of hypocalcaemia. High DCAB diets have proved to increase dry mater and water intake and production and to mitigate the effects of heat stress.

  5. Hyperventilation and blood acid-base balance in hypercapnia exposed red drum (Sciaenops ocellatus).

    Ern, Rasmus; Esbaugh, Andrew J

    2016-05-01

    Hyperventilation is a common response in fish exposed to elevated water CO2. It is believed to lessen the respiratory acidosis associated with hypercapnia by lowering arterial PCO2, but the contribution of hyperventilation to blood acid-base compensation has yet to be quantified. Hyperventilation may also increase the flux of irons across the gill epithelium and the cost of osmoregulation, owing to the osmo-respiratory compromise. Therefore, hypercapnia exposed fish may increase standard metabolic rate (SMR) leaving less energy for physiological functions such as foraging, migration, growth and reproduction. Here we show that gill ventilation, blood PCO2 and total blood [CO2] increased in red drum (Sciaenops ocellatus) exposed to 1000 and 5000 µatm water CO2, and that blood PCO2 and total blood [CO2] decrease in fish during hypoxia induced hyperventilation. Based on these results we estimate the ventilatory contributions to total acid-base compensation in 1000 and 5000 µatm water CO2. We find that S. ocellatus only utilize a portion of its ventilatory capacity to reduce the acid-base disturbance in 1000 µatm water CO2. SMR was unaffected by both salinity and hypercapnia exposure indicating that the cost of osmoregulation is small relative to SMR, and that the lack of increased ventilation in 1000 µatm water CO2 despite the capacity to do so is not due to an energetic tradeoff between acid-base balance and osmoregulation. Therefore, while ocean acidification may impact ventilatory parameters, there will be little impact on the overall energy budget of S. ocellatus. PMID:26922790

  6. Acid-base balance and hydration status following consumption of mineral-based alkaline bottled water

    Heil Daniel P

    2010-09-01

    Full Text Available Abstract Background The present study sought to determine whether the consumption of a mineral-rich alkalizing (AK bottled water could improve both acid-base balance and hydration status in young healthy adults under free-living conditions. The AK water contains a naturally high mineral content along with Alka-PlexLiquid™, a dissolved supplement that increases the mineral content and gives the water an alkalizing pH of 10.0. Methods Thirty-eight subjects were matched by gender and self-reported physical activity (SRPA, hrs/week and then split into Control (12 women, 7 men; Mean +/- SD: 23 +/- 2 yrs; 7.2 +/- 3.6 hrs/week SRPA and Experimental (13 women, 6 men; 22 +/- 2 yrs; 6.4 +/- 4.0 hrs/week SRPA groups. The Control group consumed non-mineralized placebo bottled water over a 4-week period while the Experimental group consumed the placebo water during the 1st and 4th weeks and the AK water during the middle 2-week treatment period. Fingertip blood and 24-hour urine samples were collected three times each week for subsequent measures of blood and urine osmolality and pH, as well as total urine volume. Dependent variables were analyzed using multivariate repeated measures ANOVA with post-hoc focused on evaluating changes over time within Control and Experimental groups (alpha = 0.05. Results There were no significant changes in any of the dependent variables for the Control group. The Experimental group, however, showed significant increases in both the blood and urine pH (6.23 to 7.07 and 7.52 to 7.69, respectively, a decreased blood and increased urine osmolality, and a decreased urine output (2.51 to 2.05 L/day, all during the second week of the treatment period (P Conclusions Consumption of AK water was associated with improved acid-base balance (i.e., an alkalization of the blood and urine and hydration status when consumed under free-living conditions. In contrast, subjects who consumed the placebo bottled water showed no changes over the

  7. Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth

    Fetal monitoring during labour currently fails to accurately detect acidemia. We developed a method to assess the multidimensional properties of fetal heart rate variability (fHRV) from trans-abdominal fetal electrocardiogram (fECG) during labour. We aimed to assess this novel bioinformatics approach for correlation between fHRV and neonatal pH or base excess (BE) at birth. We enrolled a prospective pilot cohort of uncomplicated singleton pregnancies at 38–42 weeks’ gestation in Milan, Italy, and Liverpool, UK. Fetal monitoring was performed by standard cardiotocography. Simultaneously, with fECG (high sampling frequency) was recorded. To ensure clinician blinding, fECG information was not displayed. Data from the last 60 min preceding onset of second-stage labour were analyzed using clinically validated continuous individualized multiorgan variability analysis (CIMVA) software in 5 min overlapping windows. CIMVA allows simultaneous calculation of 101 fHRV measures across five fHRV signal analysis domains. We validated our mathematical prediction model internally with 80:20 cross-validation split, comparing results to cord pH and BE at birth. The cohort consisted of 60 women with neonatal pH values at birth ranging from 7.44 to 6.99 and BE from −0.3 to −18.7 mmol L−1. Our model predicted pH from 30 fHRV measures (R2 = 0.90, P < 0.001) and BE from 21 fHRV measures (R2 = 0.77, P < 0.001). Novel bioinformatics approach (CIMVA) applied to fHRV derived from trans-abdominal fECG during labor correlated well with acid-base balance at birth. Further refinement and validation in larger cohorts are needed. These new measurements of fHRV might offer a new opportunity to predict fetal acid-base balance at birth. (fast track communication)

  8. Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth.

    Frasch, Martin G; Xu, Yawen; Stampalija, Tamara; Durosier, Lucien D; Herry, Christophe; Wang, Xiaogang; Casati, Daniela; Seely, Andrew Je; Alfirevic, Zarko; Gao, Xin; Ferrazzi, Enrico

    2014-12-01

    Fetal monitoring during labour currently fails to accurately detect acidemia. We developed a method to assess the multidimensional properties of fetal heart rate variability (fHRV) from trans-abdominal fetal electrocardiogram (fECG) during labour. We aimed to assess this novel bioinformatics approach for correlation between fHRV and neonatal pH or base excess (BE) at birth.We enrolled a prospective pilot cohort of uncomplicated singleton pregnancies at 38-42 weeks' gestation in Milan, Italy, and Liverpool, UK. Fetal monitoring was performed by standard cardiotocography. Simultaneously, with fECG (high sampling frequency) was recorded. To ensure clinician blinding, fECG information was not displayed. Data from the last 60 min preceding onset of second-stage labour were analyzed using clinically validated continuous individualized multiorgan variability analysis (CIMVA) software in 5 min overlapping windows. CIMVA allows simultaneous calculation of 101 fHRV measures across five fHRV signal analysis domains. We validated our mathematical prediction model internally with 80:20 cross-validation split, comparing results to cord pH and BE at birth.The cohort consisted of 60 women with neonatal pH values at birth ranging from 7.44 to 6.99 and BE from -0.3 to -18.7 mmol L(-1). Our model predicted pH from 30 fHRV measures (R(2) = 0.90, P base balance at birth. Further refinement and validation in larger cohorts are needed. These new measurements of fHRV might offer a new opportunity to predict fetal acid-base balance at birth. PMID:25407948

  9. Seawater salinity and blood acid-base balance in the lugworm, Arenicola marina (L.).

    Toulmond, A; Jouin, C

    1992-03-01

    The kinetics of variations in the blood acid base balance (ABB) were investigated in a moderately euryhaline osmoconformer, the lugworm Arenicola marina (L.), exposed to natural and experimental hypo- or hyperosmotic shocks. In natural as well as in experimental conditions, a hyposmotic shock induced a transient and essentially metabolic acidosis, probably linked to the ionic readjustments following the shock, which was rapidly overridden by a metabolic alkalosis. In field conditions, a new ABB equilibrium was then attained, the metabolic alkalosis being neutralized by the respiratory and metabolic acidosis occurring normally in the lugworm during low tide. Conversely, in the normoxic conditions of our laboratory experiments, a new ABB equilibrium was never reached. Under experimental conditions, a hyperosmotic shock always induced a respiratory and metabolic acidosis. In the field, this phenomenon must occur at the beginning of high tide and must help to restore normal blood ABB in lugworms submitted to a moderate hyposmotic shock during low tide. All the observed blood ABB variations reveal the complex intracellular processes through which the lugworm submitted to moderate osmotic shocks tentatively regulates, sometimes without any real success, its osmoticity and volume. Obviously, complementary physical, physiological and behavioral mechanisms allow the lugworm to live in sediments washed by almost fresh water during a 7-8 h 'low tide'. PMID:1604064

  10. The Importance of the Ionic Product for Water to Understand the Physiology of the Acid-Base Balance in Humans

    Adeva-Andany, María M.; Natalia Carneiro-Freire; Cristóbal Donapetry-García; Eva Rañal-Muíño; Yosua López-Pereiro

    2014-01-01

    Human plasma is an aqueous solution that has to abide by chemical rules such as the principle of electrical neutrality and the constancy of the ionic product for water. These rules define the acid-base balance in the human body. According to the electroneutrality principle, plasma has to be electrically neutral and the sum of its cations equals the sum of its anions. In addition, the ionic product for water has to be constant. Therefore, the plasma concentration of hydrogen ions depends on th...

  11. Effects of ractopamine hydrochloride on performance, rate and variation in feed intake, and acid-base balance in feedlot cattle.

    Abney, C S; Vasconcelos, J T; McMeniman, J P; Keyser, S A; Wilson, K R; Vogel, G J; Galyean, M L

    2007-11-01

    Two experiments evaluated effects of ractopamine hydrochloride (RAC) on performance, intake patterns, and acid-base balance of feedlot cattle. In Exp. 1, 360 crossbred steers (Brangus, British, and British x Continental breeding; initial BW = 545 kg) were used in a study with a 3 x 3 factorial design to study the effects of dose [0, 100, or 200 mg/(steer x d) of RAC] and duration (28, 35, or 42 d) of feeding of RAC in a randomized complete block design (9 treatments, 8 pens/treatment). No dose x duration interactions were detected (P > 0.10). As RAC dose increased, final BW (FBW; P = 0.01), ADG (P 0.10) in feedlot performance, urine pH, blood gas measurements, or variation in intake patterns between RAC and control cattle, but steers fed RAC had increased (P = 0.04) LM area, decreased (P = 0.03) yield grade, and increased (P < 0.10) time to consume 50 and 75% of daily intake relative to control steers. Our results suggest that feeding RAC for 35 d at 200 mg/(steer x d) provided optimal performance, and no effects on acid-base balance or variation in intake patterns of finishing steers were noted with RAC fed at 200 mg/(steer x d) over a 30-d period. PMID:17609477

  12. Some comments upon acid-base balance in teleost fishes and its relationship to environmental temperature

    Houston, A.H.

    1971-01-01

    It has been hypothesized that acid-base regulation in mammalian species is directed toward stabilization of body fluid pH, whereas among the poikilotherms control centers upon the maintenance of relative alkalinity. Consequently, given the known relationship between temperature and the dissociation constant of water reductions in mammalian body temperature should be accompanied by decreases in the OH/sup -//H/sup +/ ratio while, under similar circumstances, the pH of the poikilothermic tetrapods, extension of the concept of relative alkalinity regulation to teleost fishes is not wholly consistent with the data presently available. Recorded blood and plasma pH values for teleost fishes are generally below those reported for amphibians and reptiles, tending to fall within or below the levels observed in mammals under comparable thermal conditions. Moreover, they seemingly display little tendency to vary in an inverse fashion wth temperature.

  13. Acid-base balance in the developing marsupial: from ectotherm to endotherm.

    Andrewartha, Sarah J; Cummings, Kevin J; Frappell, Peter B

    2014-05-01

    Marsupial joeys are born ectothermic and develop endothermy within their mother's thermally stable pouch. We hypothesized that Tammar wallaby joeys would switch from α-stat to pH-stat regulation during the transition from ectothermy to endothermy. To address this, we compared ventilation (Ve), metabolic rate (Vo2), and variables relevant to blood gas and acid-base regulation and oxygen transport including the ventilatory requirements (Ve/Vo2 and Ve/Vco2), partial pressures of oxygen (PaO2), carbon dioxide (PaCO2), pHa, and oxygen content (CaO2) during progressive hypothermia in ecto- and endothermic Tammar wallabies. We also measured the same variables in the well-studied endotherm, the Sprague-Dawley rat. Hypothermia was induced in unrestrained, unanesthetized joeys and rats by progressively dropping the ambient temperature (Ta). Rats were additionally exposed to helox (80% helium, 20% oxygen) to facilitate heat loss. Respiratory, metabolic, and blood-gas variables were measured over a large body temperature (Tb) range (∼15-16°C in both species). Ectothermic joeys displayed limited thermogenic ability during cooling: after an initial plateau, Vo2 decreased with the progressive drop in Tb. The Tb of endothermic joeys and rats fell despite Vo2 nearly doubling with the initiation of cold stress. In all three groups the changes in Vo2 were met by changes in Ve, resulting in constant Ve/Vo2 and Ve/Vco2, blood gases, and pHa. Thus, although thermogenic capability was nearly absent in ectothermic joeys, blood acid-base regulation was similar to endothermic joeys and rats. This suggests that unlike some reptiles, unanesthetized mammals protect arterial blood pH with changing Tb, irrespective of their thermogenic ability and/or stage of development. PMID:24627357

  14. Effect of high sodium intake during 14 days of bed-rest on acid-base balance

    Frings, P.; Baecker, N.; Heer, M.

    Lowering mechanical load like in microgravity is the dominant stimulus leading to bone loss However high dietary sodium intake is also considered as a risk factor for osteoporosis and thereby might exacerbate the microgravity induced bone loss In a metabolic balance non bed-rest study we have recently shown that a very high sodium intake leads to an increased bone resorption most likely because of a mild metabolic acidosis Frings et al FASEB J 19 5 A1345 2005 To test if mild metabolic acidosis also occurs during immobilization we examined the effect of increased dietary sodium on bone metabolism and acid-base balance in eight healthy male test subjects mean age 26 25 pm 3 49 years body weight 77 98 pm 4 34 kg in our metabolic ward during a 14-day head-down tilt HDT bed-rest study The study was designed as a randomized crossover study with two study periods Each period was divided into three parts 4 ambulatory days with 200 mmol sodium intake 14 days of bed-rest with either 550 mmol or 50 mmol sodium intake and 3 recovery days with 200 mmol sodium intake The sodium intake was altered by variations in dietary sodium chloride content Blood pH P CO2 and P O2 were analyzed in fasting morning fingertip blood samples several times during the entire study Bicarbonate HCO 3 - and base excess BE were calculated according to the Henderson-Hasselbach equation Preliminary results in the acid-base balance from the first study period 4 subjects with 550 mmol and 4 subjects with 50 mmol sodium intake strongly

  15. Effect of Chewing Gum on the Acid-Base and Mineral Balance in the Oral Fluid

    Dmitriy Vaido; Elena Raspolina

    2015-01-01

    BACKGROUND Despite chewing gum (CG) is widespread, discussion about its harm and benefits is still in progress. It is unknown whether the CG effect on the teeth depends on the type of sugar substitute. The aim of the present research was to study the effect of chewing gums containing aspartame and sucralose on the acidbase balance and content of mineral components in mixed saliva after carbohydrate-containing food. METHODS The oral fluid, or “mixed” saliva had been ...

  16. Influence of different storage times and temperatures on blood gas and acid-base balance in ovine venous blood

    H.A. Hussein

    2013-01-01

    Full Text Available The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted to +4 ºC (Group I, n = 10, at RT of about 22-25 ºC (Group II, n = 10 and in an incubator adjusted to 37 ºC (Group III, n = 10 for up to 48 h. Blood samples were analysed for blood gas and acid-base indices at 0, 1, 2, 3, 4, 5, 6, 12, 24 and 48 h of storage. In comparison to the baseline value (0, there were significant decreases of blood pH of samples stored at RT and in the incubator after 1 h (p<0.05, the pH value of refrigerated blood samples exhibited insignificant changes during the study (p<0.05. Mean values of pCO2 showed a significant increase in Group I and Group III after 1 h then a progressive decrease after 12 h in all Groups. Mean pO2 values were significantly higher for Group I after 2 h and for Groups II and III after 1 h (p<0.05. In general, base excess decreased significantly for all the groups during the study especially in Groups II and III. In comparison with baseline values, in all groups, bicarbonate (HCO3 increased between 1 h and 6 h (p<0.05, and later decreased at the end of the study (p<0.05. In conclusion, status of acid-base indices of the samples stored at refrigerator and RT were found within normal reference range and it may be of clinical diagnostic use for up to 6 h.

  17. The Importance of the Ionic Product for Water to Understand the Physiology of the Acid-Base Balance in Humans

    María M. Adeva-Andany

    2014-01-01

    Full Text Available Human plasma is an aqueous solution that has to abide by chemical rules such as the principle of electrical neutrality and the constancy of the ionic product for water. These rules define the acid-base balance in the human body. According to the electroneutrality principle, plasma has to be electrically neutral and the sum of its cations equals the sum of its anions. In addition, the ionic product for water has to be constant. Therefore, the plasma concentration of hydrogen ions depends on the plasma ionic composition. Variations in the concentration of plasma ions that alter the relative proportion of anions and cations predictably lead to a change in the plasma concentration of hydrogen ions by driving adaptive adjustments in water ionization that allow plasma electroneutrality while maintaining constant the ionic product for water. The accumulation of plasma anions out of proportion of cations induces an electrical imbalance compensated by a fall of hydroxide ions that brings about a rise in hydrogen ions (acidosis. By contrast, the deficiency of chloride relative to sodium generates plasma alkalosis by increasing hydroxide ions. The adjustment of plasma bicarbonate concentration to these changes is an important compensatory mechanism that protects plasma pH from severe deviations.

  18. Dry period cooling ameliorates physiological variables and blood acid base balance, improving milk production in murrah buffaloes

    Aarif, Ovais; Aggarwal, Anjali

    2016-03-01

    This study aimed to evaluate the impact of evaporative cooling during late gestation on physiological responses, blood gas and acid base balance and subsequent milk production of Murrah buffaloes. To investigate this study sixteen healthy pregnant dry Murrah buffaloes (second to fourth parity) at sixty days prepartum were selected in the months of May to June and divided into two groups of eight animals each. One group of buffaloes (Cooled/CL) was managed under fan and mist cooling system during dry period. Group second buffaloes (Noncooled/NCL) remained as control without provision of cooling during dry period. The physiological responses viz. Rectal temperature (RT), Respiratory rate (RR) and Pulse rate were significantly ( P group 2, with the provision of cooling. Skin surface temperature at thorax was significantly lower in cooled group relative to noncooled group. Blood pH and pO2 were significantly ( P group as compared to the cooled group. pCO2, TCO2, HCO3, SBC, base excess in extracellular fluid (BEecf), base excess in blood (BEb), PCV and Hb were significantly ( P group as compared to noncooled group. DMI was significantly ( P group of Murrah buffaloes.

  19. Dry period cooling ameliorates physiological variables and blood acid base balance, improving milk production in murrah buffaloes

    Aarif, Ovais; Aggarwal, Anjali

    2016-03-01

    This study aimed to evaluate the impact of evaporative cooling during late gestation on physiological responses, blood gas and acid base balance and subsequent milk production of Murrah buffaloes. To investigate this study sixteen healthy pregnant dry Murrah buffaloes (second to fourth parity) at sixty days prepartum were selected in the months of May to June and divided into two groups of eight animals each. One group of buffaloes (Cooled/CL) was managed under fan and mist cooling system during dry period. Group second buffaloes (Noncooled/NCL) remained as control without provision of cooling during dry period. The physiological responses viz. Rectal temperature (RT), Respiratory rate (RR) and Pulse rate were significantly ( P < 0.05) lower in group 2, with the provision of cooling. Skin surface temperature at thorax was significantly lower in cooled group relative to noncooled group. Blood pH and pO2 were significantly ( P < 0.05) higher in heat stressed group as compared to the cooled group. pCO2, TCO2, HCO3, SBC, base excess in extracellular fluid (BEecf), base excess in blood (BEb), PCV and Hb were significantly ( P < 0.05) higher in cooled group as compared to noncooled group. DMI was significantly ( P < 0.05) higher in cooled relative to noncooled animals. Milk yield, FCM, fat yield, lactose yield and total solid yield was significantly higher ( P < 0.05) in cooled group of Murrah buffaloes.

  20. Ion and acid-base balance in three species of Amazonian fish during gradual acidification of extremely soft water.

    Wilson, R W; Wood, C M; Gonzalez, R J; Patrick, M L; Bergman, H L; Narahara, A; Val, A L

    1999-01-01

    Sensitivity to acid water was assessed in three species of Amazonian fish that encounter naturally acidic blackwaters to differing degrees in the wild: tambaqui (Colossoma macropomum), matrincha (Brycon erythropterum), and tamoatá (Hoplosternum littorale), in decreasing order of occurrence in blackwater. Fish were exposed to a graded reduction in water pH, from pH 6 to 5 to 4 to 3.5, followed by return to pH 6. Fish were exposed to each new pH for 24 h. During these exposures, net transfers of ions (Na+, K+, Cl-, and Ca2+) and acid-base equivalents to and from the external water were used as physiological indicators of acid tolerance. Exposure to pH 5 had a minimal effect on net ion fluxes. Significant net losses of all ions (except Ca2+) were recorded in all three species during the first few hours of exposure to pH 4. However, ion balance was usually restored within 18 h at pH 4. Exposure to pH 3.5 caused even greater ion losses in all three species and proved to be acutely lethal to tamoatá. Matrincha sustained irreversible physiological damage at pH 3.5, as ion fluxes did not recover following return to pH 6 and there was some mortality. Tambaqui suffered the least ionoregulatory disturbances at pH 3.5 and was the only species to make a full recovery on return to pH 6. In all species, there was a tendency for ammonia excretion to increase at low water pH, but even at pH 3.5, there was no significant net uptake of acid from the water. Overall, there was a strong relationship between the magnitude of ionic disturbances and the lethality of exposure to low pH. The relative insensitivity of the ionoregulatory system of tambaqui to low pH indicates that this is a feature of fish native to blackwater systems rather than one that is common to all Amazon fish. PMID:10222322

  1. Blood acid-base balance as a function of water oxygenation: a study at two different ambient CO2 levels in the dogfish, Scyliorhinus canicula.

    Truchot, J P; Toulmond, A; Dejours, P

    1980-07-01

    In the unanesthetized dogfish, Scyliorhinus canicula, oxygen and carbon dioxide partial pressures and concentrations in inspired and expired water and the acid-base balance of arterial blood, pHa and PcCO2, were determined. Each dogfish was exposed to waters differing in oxygenation and in CO2 levels, which was controlled with a pH-CO2-stat device, for successive 2- to 3-h periods. The four ambient conditions were: normoxia-normocapnia (inspired PO2, PIO2 ca 160 Torr; PICO2 ca 0.3 Torr), hyperoxia-normocapnia (PIO2 ca 730 Torr), hyperoxia-hypercapnia (PICO2 ca 1.0 Torr); normoxia-hypercapnia. At both low and high ambient CO2, the inspired-expired O2 and CO2 concentration differences increased in hyperoxia. Ventilation was depressed, and concomitantly, PACO2 increased and the arterial plasma pH decreased. The hypercapnic acidosis was rapidly but only partially compensated by an increase of the plasma bicarbonate concentration. Due to the buffer action of carbonate in sea water, low and high ambient CO2 levels corresponded respectively to high and low values of the CO2 capacitance coefficient, betaWCO2. At both ambient oxygenation levels, the expired-inspired PCO2 difference was greater at low than at high betaWCO2. At a given ambient CO2 level, expired PCO2, PECO2, wash higher in hyperoxia than in normoxia; an effect more marked at low than at high betaWCO2. Thus, the water capacitance coeffcient betaWCO2 is an important factor determining PECO2 values and probably arterial blood acid-base balance. As a general conclusion, the acid-base balance of the arterial blood in the dogfish is very much dependent on the conditions of the oxygenation and acid-base balance of the ambient water which consequently should be carefully controlled. PMID:6771856

  2. Effects of xylazine on acid-base balance and arterial blood-gas tensions in goats under different environmental temperature and humidity conditions

    E.G.M. Mogoa

    2000-07-01

    Full Text Available The effects of acute exposure to 3 different temperature and humidity conditions on arterial blood-gas and acid-base balance in goats were investigated after intravenous bolus administration of xylazine at a dose of 0.1 mg/kg. Significant (P < 0.05 changes in the variables occurred under all 3 environmental conditions. Decreases in pH, partial pressure of oxygen and oxyhaemoglobin saturation were observed, and the minimum values for oxygen tension and oxyhaemoglobin saturation were observed within 5 min of xylazine administration. The pH decreased to its minimum values between 5 and 15 min. Thereafter, the variables started to return towards baseline, but did not reach baseline values at the end of the 60 min observation period. Increases in the partial pressure of carbon dioxide, total carbon dioxide content, bicarbonate ion concentration, and the actual base excess were observed. The maximum increase in the carbon dioxide tension occurred within 5 min of xylazine administration. The increase in the actual base excess only became significant after 30 min in all 3 environments, and maximal increases were observed at 60 min. There were no significant differences between the variables in the 3 different environments. It was concluded that intravenous xylazine administration in goats resulted in significant changes in arterial blood-gas and acid-base balance that were associated with hypoxaemia and respiratory acidosis, followed by metabolic alkalosis that continued for the duration of the observation period. Acute exposure to different environmental temperature and humidity conditions after xylazine administration did not influence the changes in arterial blood-gas and acid-base balance.

  3. Effects of Various Calcium Levels and Anionic Salts on Blood Acid-Base Balance, Growth Performance and Development of Tibial Dyscondroplasia in Broilers

    KARAMÜFTÜOĞLU, Şerife; KOCABAĞLI, Neşe

    2001-01-01

    The aim of this trial was to investigate the effects of chlorine and phosphate salts in the diet, and 2 different levels of diet Ca,on the acid-based balance,growth performance and development of tibial dyscondroplasia (TD)in broiler chicks. Three hundred Ross X PM3, 1-day-old broiler chicks were used during the 5-week trial.Chicks were divided into 6 groups. Three groups (2 experimental and 1 control)were given diets with Ca levels near the bottom limit of the normal requirement (starter ...

  4. EFFECTS OF HEAT STRESS ON BLOOD ACID-BASE BALANCE AND MINERAL CONTENT IN GUINEA FOWLS WHEN DRINKING WATER TREATED WITH MAGNETIC FIELD WAS USED

    Beata GŁOWIŃSKA

    2011-01-01

    Full Text Available The purpose of the study was to examine the effect of 24-hour heat stress on blood acid-base balance parameters and mineral content in guinea fowls when drinking water treated with magnetic field was used. The maximum environmental temperature at the end of the present experiment was 32oC. The relative humidity was maintained at 55% (±2. Blood samples were collected from birds three times: in the 1st, 12th and 24th hour of stress. Exposure to heat stress significantly increased blood bicarbonate ion concentration (HCO3 -, content of buffer alkali (BB and decreased shortage of alkali (BE but only in the 12th hour of stress. In the level of oxygen pressure (pO2 and percentage of oxygen content (O2sat in the 12th and 24th hour of the experiment statistically high significant decrease occurred. In consequence of high environmental temperature the statistically significant decrease of sodium was found. No changes in the level of potassium and chlorine ions in guinea fowls watered magnetized water occurred.

  5. Lung compliance, plasma electrolyte levels and acid-base balance are affected by scorpion envenomation in anesthetized rats under mechanical ventilation.

    Andrade, Marcus V; Caramez, Maria Paula R; Abreu, Elnara Marcia N N; Dolnikoff, Marisa; Omar, Erick D; Velasco, Irineu T; Cunha-Melo, José R

    2004-05-01

    To determine the effects of Tityus serrulatus scorpion toxin on lung compliance and resistance, ionic equilibrium and acid-base balance over time in anesthetized and mechanically ventilated rats, we measured air flow, tracheal and esophageal pressure. Lung volume was obtained by electronic integration of airflow signal. Arterial blood samples were collected through a catheter at baseline (before) and 5, 15, 30 and 60 min after scorpion toxin injection for arterial blood gases, bicarbonate, and alkali reserve levels as well as for, sodium, potassium, magnesium, glucose, lactate, hematocrit, and osmolality analysis. Injection of the gamma fraction of the T. serrulatus scorpion venom in rats under mechanical ventilatory support leads to a continuous decrease in lung compliance secondary to pulmonary edema, but no change in airway resistance. The changes in arterial blood gases characterizing metabolic acidosis were accompanied by an increase in arterial lactate and glucose values, suggesting a scorpion toxin-induced lactic acidosis, in association with poor tissue perfusion (hypotension and low cardiac output). Moreover, scorpion toxin injection resulted in hyperosmolality, hyperkalemia, hypermagnesemia and an increase in hematocrit. The experiments have shown a clinically relevant animal model to study severe scorpion envenoming and may help to better understand the scorpion envenoming syndrome. PMID:15313452

  6. Importance of blood gas measurements in perinatal asphyxia and alternatives to restore the acid base balance status to improve the newborn performance

    H. Orozco-Gregorio

    2007-01-01

    Full Text Available Prolonged or intermittent asphyxia in utero and during farrowing weakens piglets and renders them less capable of adaptation to extrauterine life. Piglets with lesser viability at birth have increased blood pCO2 and blood lactic acid concentrations and decreased blood pH. Moreover, the ability to thermoregulate during an acute cold stress is inversely related to umbilical blood lactate concentrations. Blood gas measurements and noninvasive estimations provide important information about oxygenation. The general goals of oxygen therapy in the neonate are to maintain adequate arterial PaO2 and SaO2, and to minimize cardiac work and the work of breathing. Arterial blood gas determinations of pCO2 provide the most accurate determinations of the adequacy of alveolar ventilation. Blood gases obtained in the immediate perinatal period can help assess perinatal asphyxia, but particular attention must be paid to the sampling site, the time of life, and the possible and proven diagnoses. The decision to obtain blood gases must be weighed by the individual clinician against the potential benefits. Current measures for restoring the acid base balance status in the newborn with perinatal asphyxia are discussed.

  7. Zero balance ultrafiltration (Z-BUF) in blood-primed CRRT circuits achieves electrolyte and acid-base homeostasis prior to patient connection.

    Hackbarth, Richard M; Eding, Dawn; Gianoli Smith, Carla; Koch, Ada; Sanfilippo, Dominic J; Bunchman, Timothy E

    2005-09-01

    Infants requiring CRRT present a unique challenge due to the large circuit volume to blood volume ratio. Blood priming is often used, but some patients can become unstable during the initiation of CRRT due to electrolyte and acid-base imbalance. We postulated that using Z-BUF we could normalize electrolytes and improve the acid base status of the prime prior to patient connection. To test this we set up a circuit using the Baxter BM-25 CRRT pump, a polysulfone or AN-69 membrane, and a three-way stopcock. The circuit was primed with a 60/40 mix of expired autologous donor pRBCs and 5% albumin. The modalities of CVVH, CVVHD, and CVVHDF were compared for relative efficacy. Electrolytes, lactate, pH, cytokines (TNF-alpha, IL-1beta, bradykinin, and IL-6) were measured. Plasma hemoglobin levels were also measured before and after the Z-BUF procedure. Bradykinin production and elimination in AN-69 membrane circuits were assessed. All lab values equilibrated by 35 minutes. All CRRT modalities were equally efficacious for Z-BUF. Cytokine production or significant hemolysis was not found. In addition, no bradykinin accumulation occurred in AN-69 membrane-containing circuits. We conclude that Z-BUF is a simple and effective way to normalize electrolyte and acid-base status in the CRRT circuit when blood priming is required. PMID:15947984

  8. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to calcium and potassium and maintenance of normal acid-base balance (ID 400, 407) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    Tetens, Inge

    claims in relation to calcium and potassium and maintenance of normal acid-base balance. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from...... stakeholders. The food constituents that are the subject of the health claims are calcium and potassium. The Panel considers that calcium and potassium are sufficiently characterised. The claimed effects are “calcium contributes to acid/base balance within metabolism” and “mineral/potassium: key function......-base balance is a beneficial physiological effect. The Panel notes that no evidence has been provided showing that the dietary intake of calcium and potassium affects normal acid-base balance in the general healthy population. The Panel concludes that a cause and effect relationship has not been established...

  9. Reducing Dietary Cation-Anion Difference on Acid-Base Balance, Plasma Minerals Level and Anti-Oxidative Stress of Female Goats

    WU Wen-xuan; YANG Yi; ZHANG Ji-kun; LI Sheng-li

    2013-01-01

    Reducing dietary cation-anion difference (DCAD) has been proved an effective way to prevent milk fever in dairy cows. Based on the similar physiological gastro-intestinal tract anatomy and metabolic process between female goats and dairy cows, this study was conducted to evaluate the effects of varying DCAD on fluid acid-base status, plasma minerals concentration and anti-oxidative stress capacity of female goats. Urinary pH, plasma Ca, P and Mg;and anti-oxidative stress indices of total superoxide dismutase (T-SOD), hydrogen peroxide (H2O2), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were determined to evaluate the effect. Forty-eight Guizhou black female goats ((15±1.9) mon of old, (22.3±3.75) kg of BW) were randomly allocated to 4 blocks of 12 goats each and were fed 1 of 4 diets differed in DCAD level (calculated as Na+K-Cl-S, mEq kg-1 DM). Levels of DCAD were preliminarily designed to be control (+150 mEq kg-1 DM, CON), high DCAD (+300 mEq kg-1 DM, HD), low DCAD (0 mEq kg-1 DM, LD) and negative DCAD (-150 mEq kg-1 DM, ND), respectively. A commercial anionic salts (Animate) and sodium bicarbonate (NaHCO3) were supplemented to reduce and increase DCAD level, respectively. There was no difference in dry matter intake for 4 groups of goats. Urine pH was aggressively decreased (P0.05) plasma Mg level. There was no significant (P>0.05) difference in plasma GSH-Px activity and H2O2, but anionic salts supplementation in LD and ND significantly increased (P<0.05) plasma T-SOD activity and tended to reduce MDA (P<0.1) over HD and CON. Results from this study indicated that reducing DCAD could decrease urine pH and increase plasma Ca concentration of female goats. Additionally, reducing DCAD was helpful to enhance anti-oxidative stress capability of female goats.

  10. PBL教学法在水、电解质和酸碱平衡教学中的应用%The Application of PBL Teaching Method in Water-electrolyte Metabolism and Acid-base Balance Teaching

    叶俊; 章宏伟; 黄华兴

    2015-01-01

    目的::探讨PBL(problem-based learning)教学法在水、电解质和酸碱平衡教学中的应用优势。方法:选取南京医科大学2011级临床医学七年制6个班级的学生,按自然班随机分为实验组(n=79)和对照组(n=78),实验组采用PBL教学模式,对照组采用传统教学模式(LBL),通过调查问卷及课后测试对两种教学模式进行综合评价。结果:实验组理论测试成绩明显优于对照组(p=0.026),调查问卷显示:PBL组在自主学习能力、病例分析能力、团队协作能力以及在掌握理论知识与临床疾病的联系方面均优于LBL组。结论:与LBL教学法相比,PBL教学法在水、电解质和酸碱平衡教学中应用效果更好,优势更明显。%Objective: To investigate the advantage of PBL teaching method in water-electrolyte metabolism and acid-base balance teaching. Method:Choose 6 classes of students from Nanjing medical university and randomly divided into experimental group (n=79) and control group (n=78), the experimental group using PBL teaching method and the control group using traditional LBL teaching method, evaluating these two methods by analyze the average scores of the test and the survey. Results:The average scores of experimental group were higher than that in the control group (p=0.026). The survey showed that the experimental group was better in autonomous learning, case analysis, teamwork and using the theoretical knowledge and clinical cases than control group. Conclusion:PBL teaching method was much better than LBL in water-electrolyte metabolism and acid-base balance teaching.

  11. Equilíbrio ácido-base e hidroeletrolítico em eqüinos com cólica Acid-base and hidroelectrolytic balance in colic horses

    Paula Alessandra Di Filippo

    2008-08-01

    Full Text Available Foram utilizados setenta eqüinos distribuídos em três grupos experimentais, G1 (vinte eqüinos hígidos, G2 (vinte e cinco eqüinos com cólica, os quais passaram por tratamento clínico ou cirúrgico e sobreviveram e G3 (vinte e cinco eqüinos com cólica, os quais passaram por tratamento clínico ou cirúrgico e foram a óbito ou foram sacrificados. Amostras de sangue foram obtidas em dez diferentes momentos, mediante punção da jugular, para estudo do equilíbrio ácido-base e hidroeletrolítico. Os eqüinos com cólica apresentaram diminuição (PSeventy horses were distributed into three experimental groups ad follows: G1, twenty healthy animals; G2, twenty-five colic horses that survived after clinical or surgical treatment; and G3, twenty-five colic horses that were sacrificed or died after clinical or surgical treatment. Blood samples were taken from the jugular vein to assess acid-base balance and water-electrolyte balance. Colic horses had lower pH(v (P<0.05, mainly G3 animals. Acidosis was confirmed by the lower pH(v associated with decreased pCO2(v, cBase(v and cHCO-3(vP, which was probably due to an increased production of lactate during anaerobic glycolysis as a result from hypovolemia. Furthermore, hyponatremia, hypokalemia and hyperchloremia were detected. The presence and the extent of the imbalances contributed substantially to the prognosis of colic horses.

  12. L-lysine escinat, thiotriazolin, gordox and mydocalm influence on oxygen tension in the intestinal wall and acid-base balance and limited proteolysis in intestinal venous blood in terms of intraabdominal hypertension modeling

    Sapegin V.I.

    2014-11-01

    Full Text Available In acute experiments on rabbits there were studied changes in oxygen tension in the intestinal wall tissues, acid-base balance and limited proteolysis and its inhibitors in intestinal venous blood, protective action of L-lysine escinat (0,15 mg/kg / single dose, thiotriazolin (25 mg/kg / single dose, aprotinin (gordox (10,000 units/kg / single dose in sequential modeling of standard levels increasing of intra-abdominal hypertension (IAH — 50, 100, 150, 200, 250, 300, 350 m H2O, and also of tolperison (mydocalm (5 mg/kg / single dose on modeling of stable 3-hour IAH 200 m H2O. The IAH modeling was performed by means of stand of our construction. Under the influence of IAH the compensated metabolic acidosis in intestinal venous blood with a compensative hyperpnoe develops, decline of oxygen tension in tissues and activating of a limited proteolysis as well as decline of its inhibitors activity in intestinal venous blood occur. By the degree of metabolic acidosis prevention investigational preparations were distributed as follows gordox > thiotriazolin = L-lysine escinat = mydocalm, and by prevention of decline of oxygen tension in tissues — thiotriazolin > L-lysine escinat > mydocalm > gordox, it is is connected with different rate of methabolic products excretion into the blood, due to the influence on blood circulation and transcapilary exchange. By the degree of prevention of proteolytic activity and inhibitory potential changes, investigational preparations were distributed as follows: gordox > mydocalm > thiotriazolin > L-lysine escinat, this is connected with inhibition of proteolysis in gordox, and in other ones – with reduction of ischemic damage of tissues. Owing to different mechanism of action thiotriazolin, L-lysine escinat and mydocalm may be simultaneously recommended for a conservative treatment of patients with intraabdominal hypertension syndrome.

  13. Effects of thoracic explosive injury on blood gas and acid base balance in rabbits at high altitude%高原家兔胸部爆炸伤对血气及酸碱平衡的影响

    陈忠东; 李素芝; 王洪亚; 吴前进; 肖嘉芳; 易映红

    2011-01-01

    Objective To study the changes of arterial blood gas and acid base balance in rabbits suffered from thoracic explosive injury at high altitude. Methods 24 rabbits were randomly divided into high - altitude injured group ( group A ), highaltitude control group ( group B ) and plain injured group ( group C ). In group A and C, a detonator was placed above the 5th right intercostal space of rabbit and exploded to cause the thoracic injury. In group B, animals were anesthetized and cannulated without thoracic injury. Blood samples were respectively collected before injury and at 1,3,6 h after injury for arterial blood gas analysis.Results After injury,each injured group showed persistent metabolic acidosis and lower blood gas parameters than those before injury ( P < 0.05 or P < 0.01 ). There were significant differences in each blood gas parameter between group A and C ( P < 0.05 or P <0.01 ). Conclusion Decreased blood gas parameters and persistent metabolic acidosis are the most characteristic changes in rabbits suffered from thoracic explosive injury at high altitude. These changes are of significant value in the early treatment of such injury.%目的 研究高原家兔胸部爆炸伤后动脉血气分析及酸碱平衡的变化特点.方法 将家兔随机分为高原致伤组、高原对照组和平原致伤组,分别于伤前和伤后1、3、6 h采集动脉血进行血气分析.结果 伤后各致伤组均表现为持续性的代谢性酸中毒,与伤前比较血气指标值明显下降(P<0.05或P<0.01),伤后各时点高原致伤组与平原致伤组血气指标比较均有显著差异(P<0.05或P<0.01).结论 伤后高原致伤组的血气指标降低以及持续性代谢性酸中毒是高原胸部爆炸伤的最主要特征性改变,对于及早救治具有重要意义.

  14. Experimental antegrade enema: effects on water, electrolyte and acid-base balances with different solutions Enema anterógrado experimental: equilíbrio hídrico eletrolítico e ácido-base em coelhos submetidos a enema com diferentes soluções

    Laura Helman; José Luiz Martins; Djalma José Fagundes; Edward Esteves; Cirilo de Paula Lima; Álisson de Souza Costa

    2007-01-01

    PURPOSE: To study the effects on the water, electrolyte, and acid-base balances in rabbits submitted to antegrade enema with different solutions through appendicostomy. METHODS: Forty male New Zealand rabbits were submitted to appendicostomy, and distributed in 4 groups, according to the antegrade enema solution: PEG group, polyethylene glycol electrolyte solution (n=10); ISS group, isotonic saline solution (n=10); GS group, glycerin solution (n=10); SPS group, sodium phosphate solution (n=10...

  15. Efeito do tempo após a ingestão de leite sobre o equilíbrio ácido-básico de bezerros Effect of the time after milk feeding on the acid-base balance of calves

    J.A.N. Lisbôa

    2003-12-01

    Full Text Available Blood pH, carbon dioxide and oxygen partial pressures, bicarbonate, total carbon dioxide, base excess, standard bicarbonate and oxygen saturation concentrations were measured by blood gas analyses in a study of assessment of the acid-base status in young calves. Venous blood samples were taken from 80 healthy female Holstein calves, from four to 30 days of age. The calves were divided in two groups based on the interval between the morning milk feeding and the blood sample collection (up to 30 minutes or over two hours. Greater alkali reserve and higher carbon dioxide pressure values were observed later than 2h after milk feeding, supporting the influence of the diet on the acid-base balance of calves during the milk feeding phase.

  16. Acid-base disturbance in patients with cirrhosis

    Henriksen, Jens H; Bendtsen, Flemming; Møller, Søren

    2015-01-01

    PURPOSE: Acid-base disturbances were investigated in patients with cirrhosis in relation to hemodynamic derangement to analyze the hyperventilatory effects and the metabolic compensation. METHODS: A total of 66 patients with cirrhosis and 44 controls were investigated during a hemodynamic study......, and effects of unidentified ions (all Pacid-base disturbances could not be identified. CONCLUSION: Hypocapnic alkalosis is related to disease severity and hyperdynamic systemic circulation in patients with cirrhosis. The metabolic compensation includes...... alterations in serum albumin and water retention that may result in a delicate acid-base balance in these patients....

  17. Carbonic anhydrase 5 regulates acid-base homeostasis in zebrafish.

    Ruben Postel

    Full Text Available The regulation of the acid-base balance in cells is essential for proper cellular homeostasis. Disturbed acid-base balance directly affects cellular physiology, which often results in various pathological conditions. In every living organism, the protein family of carbonic anhydrases regulate a broad variety of homeostatic processes. Here we describe the identification, mapping and cloning of a zebrafish carbonic anhydrase 5 (ca5 mutation, collapse of fins (cof, which causes initially a collapse of the medial fins followed by necrosis and rapid degeneration of the embryo. These phenotypical characteristics can be mimicked in wild-type embryos by acetazolamide treatment, suggesting that CA5 activity in zebrafish is essential for a proper development. In addition we show that CA5 regulates acid-base balance during embryonic development, since lowering the pH can compensate for the loss of CA5 activity. Identification of selective modulators of CA5 activity could have a major impact on the development of new therapeutics involved in the treatment of a variety of disorders.

  18. Molten fatty acid based microemulsions.

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

    2016-06-21

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

  19. Jigsaw Cooperative Learning: Acid-Base Theories

    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…

  20. Efeito dos ionóforos e do balanço eletrolítico da dieta sobre o desempenho e a incidência de discondroplasia tibial em frangos de corte na fase inicial Effect of ionophores and acid-base balance on performance and incidence of tibial dyschondroplasia in 21-d old broiler chicks

    José Rodrigo Galli Franco

    2004-02-01

    Full Text Available O objetivo do trabalho foi avaliar o efeito dos ionóforos e balanços eletrolíticos da dieta (BED no desempenho e na incidência de discondroplasia tibial (DT em frangos de corte de 1 a 21 dias de idade. Foram utilizados 1.600 pintos de corte, machos, "Cobb", distribuídos em um delineamento inteiramente casualizado, em esquema fatorial com três níveis de BED (230, 260 e 290 mEq/kg e dois ionóforos (lasalocida e salinomicina, mais dois tratamentos controle (230 e 260 mEq/kg, isentos de ionóforos, totalizando oito tratamentos, quatro repetições e 50 aves por unidade experimental. Verificou-se interação entre ionóforos e balanços para o peso aos 21 dias (P21 e consumo de ração (CR. Desdobrando essa interação, observou-se que, com a utilização de lasalocida, houve comportamento quadrático, em função do BED para o P21 e CR, sendo os valores mínimos para essas variáveis obtidos com 261 e 268 mEq/kg, respectivamente. Quando se utilizou salinomicina, não houve efeito do BED. A conversão alimentar (CA não sofreu influência dos ionóforos e do BED. Na comparação utilizando contrastes, constatou-se melhor P21 das aves com a adição de ionóforos às dietas, todavia, para o CR e CA não foram encontradas diferenças. Na comparação entre ionóforos, as aves que receberam salinomicina apresentaram peso superior àquelas que receberam lasalocida. O uso de salinomicina não mostrou efeito do BED sobre as áreas epifisárias, entretanto, com o uso do lasalocida, o incremento do BED proporcionou aumento linear dessas áreas. Concluiu-se que o uso de dietas com lasalocida reduziram o desempenho dos frangos, sendo que as aves que receberam salinomicina apresentaram maior P21 e não sofreram influência do BED na incidência de DT. No entanto, para lasalocida, houve aumento das áreas ósseas, que caracterizam a DT, com o aumento do BED.The objective of this research was to evaluate the effect of different ionophores and acid-base

  1. 钠钾镁钙葡萄糖注射液对创伤失血性休克兔复苏过程中血流动力学、血糖和酸碱平衡的影响%The effects of Sodium Potassium Magnesium, Calcium and Glucose Injection on hemodynamics, blood glucose and the acid-base balance in rabbits with traumatic hemorrhagic shock LI

    李芹; 刘慧; 周莹; 许铁

    2015-01-01

    Objective To explore the effects of Sodium Potassium Magnesium, Calcium and Glucose Injection on hemodynamics, blood glucose and the acid-base balance in rabbits with traumatic hemorrhagic shock (THS). Methods We induced THS by Lamson’s method. We divided the rabbits into four groups (n=8):NC group, NS group, LR group and SPMCG group. Different interventions on limited resuscitation phase were performed respectively. The same interventions were performed on full resuscitation phase. The blood samples Were collected at pre-shock,post-shock,the end of limited resuscitation and full resuscitation for blood gas analysis. Results MAP, HR, RF, PaCO2 and the blood glucose in infusion groups there were no significant differences (P>0.05). After the fluid resuscitation, compared with NS group and LR group, pH, the blood lactate (Lac) and base excess (BE) in SPMCG group had been significantly improved (P0.05). Conclusion In the fluid resuscitation of traumatic hemorrhagic shock rabbits, compared with saline solution and lactated Ringer’s, sodium potassium magnesium calcium and glucose injection is more advantageous to maintain the acid-base balance.%目的:探讨钠钾镁钙葡萄糖注射液对创伤失血性休克兔血流动力学、血糖和酸碱平衡的影响。方法采用Lamson’s法制作创伤失血性休克兔模型。日本长耳大白兔32只随机均分为4组:正常对照(NC)组,生理盐水(NS)组,乳酸钠林格氏液(LR)组,钠钾镁钙葡萄糖注射液(SPMCG)组;在限制复苏期给予不同干预,在充分复苏期给予相同干预;于休克前即基础期(T1)、休克末(T2)、限制复苏期末(T3)、充分复苏期末(T4)各时间点采动脉血进行血气分析。结果输液各组平均动脉压(MAP)、心率(HR)、呼吸频率(RF)、动脉血二氧化碳分压(PaCO2)以及血糖组间比较差异无统计学意义(P>0.05)。经液体复苏后, SPMCG组实验动物的pH

  2. Physiological roles of acid-base sensors.

    Levin, Lonny R; Buck, Jochen

    2015-01-01

    Acid-base homeostasis is essential for life. The macromolecules upon which living organisms depend are sensitive to pH changes, and physiological systems use the equilibrium between carbon dioxide, bicarbonate, and protons to buffer their pH. Biological processes and environmental insults are constantly challenging an organism's pH; therefore, to maintain a consistent and proper pH, organisms need sensors that measure pH and that elicit appropriate responses. Mammals use multiple sensors for measuring both intracellular and extracellular pH, and although some mammalian pH sensors directly measure protons, it has recently become apparent that many pH-sensing systems measure pH via bicarbonate-sensing soluble adenylyl cyclase. PMID:25340964

  3. ACID-BASE INTERACTIONS BETWEEN POLYMERS AND FILLERS

    WANG Qingguo; CHEN Fute; HUANG Yuanfu; ZHOU Qingli

    1987-01-01

    Inverse gas chromatography(IGC) and Fourier-transform infrared (FT-IR) techniques were applied to determining the relative acid-base strength of polymers and coupling agents. The acid-base characteristics of fillers such as CaCO3 could be altered by treatment with different coupling agents. It was shown that some mechanical properties of filled polymers were obviously associated with acid-base interactions between polymers and fillers.

  4. Acid-base analysis: a critique of the Stewart and bicarbonate-centered approaches.

    Kurtz, Ira; Kraut, Jeffrey; Ornekian, Vahram; Nguyen, Minhtri K

    2008-05-01

    When approaching the analysis of disorders of acid-base balance, physical chemists, physiologists, and clinicians, tend to focus on different aspects of the relevant phenomenology. The physical chemist focuses on a quantitative understanding of proton hydration and aqueous proton transfer reactions that alter the acidity of a given solution. The physiologist focuses on molecular, cellular, and whole organ transport processes that modulate the acidity of a given body fluid compartment. The clinician emphasizes the diagnosis, clinical causes, and most appropriate treatment of acid-base disturbances. Historically, two different conceptual frameworks have evolved among clinicians and physiologists for interpreting acid-base phenomena. The traditional or bicarbonate-centered framework relies quantitatively on the Henderson-Hasselbalch equation, whereas the Stewart or strong ion approach utilizes either the original Stewart equation or its simplified version derived by Constable. In this review, the concepts underlying the bicarbonate-centered and Stewart formulations are analyzed in detail, emphasizing the differences in how each approach characterizes acid-base phenomenology at the molecular level, tissue level, and in the clinical realm. A quantitative comparison of the equations that are currently used in the literature to calculate H(+) concentration ([H(+)]) is included to clear up some of the misconceptions that currently exist in this area. Our analysis demonstrates that while the principle of electroneutrality plays a central role in the strong ion formulation, electroneutrality mechanistically does not dictate a specific [H(+)], and the strong ion and bicarbonate-centered approaches are quantitatively identical even in the presence of nonbicarbonate buffers. Finally, our analysis indicates that the bicarbonate-centered approach utilizing the Henderson-Hasselbalch equation is a mechanistic formulation that reflects the underlying acid-base phenomenology. PMID

  5. FERTILIZATION OF VINE BY A 5-AMINOLEVULINIC ACID-BASED FERTILIZER AND ITS PROFITABILITY

    VLADIMR IMANSK; Otto LOEK

    2013-01-01

    In this work we investigated the effect of different doses of NPKS fertilizer added into the soil for nutrient contents in the soil, as well as the quantity and quality of grapes. During the vegetation of the vine, we tested the 5-aminolevulinic acid-based fertilizer (ALA). We summarize that higher doses of fertilizer added into soil caused higher amounts of available nutrients. During the vegetation of the vine an increase of ALA had a positive effect on the optimal balance of nutrients. Fer...

  6. Boronic acid-based autoligation of nucleic acids

    Barbeyron, R.; Vasseur, J.-J.; Smietana, M.;

    2013-01-01

    Abstract: The development of synthetic systems displaying dynamic and adaptive characteristics is a formidable challenge with wide applications from biotechnology to therapeutics. Recently, we described a dynamic and programmable nucleic acid-based system relying on the formation of reversible...

  7. Teaching acid/base physiology in the laboratory

    Friis, Ulla G; Plovsing, Ronni; Hansen, Klaus;

    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 students with unambiguous and reproducible data that clearly would illustrate the theory in practice. The laboratory exercise was developed to include both metabolic acidosis and respiratory alkalosis. Data were collected from 56 groups of medical...... students that had participated in this laboratory exercise. The acquired data showed very consistent and solid findings after the development of both metabolic acidosis and respiratory alkalosis. All results were consistent with the appropriate diagnosis of the acid/base disorder. Not one single group...

  8. Acid-base homeostasis in the human system

    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.

  9. Pattern of acid base abnormalities in critically ill patinets

    To find out the pattern of acid base abnormalities in critically ill patients in a tertiary care health facility. Study Design: A descriptive study. Place and Duration of Study: The study was carried out in the department of pathology, Combined Military Hospital Kharian from January 2013 to June 2013. Patients and Methods: Two hundred and fifty patients suffering from various diseases and presenting with exacerbation of their clinical conditions were studied. These patients were hospitalized and managed in acute care units of the hospital. Arterial blood gases were analysed to detect acid base status and their correlation with their clinical condition. Concomitant analysis of electrolytes was carried out. Tests related to concurrent illnesses e.g. renal and liver function tests, cardiac enzymes and plasma glucose were assayed by routine end point and kinetic methods. Standard reference materials were used to ensure internal quantify control of analyses. Results: Two hundred and fifteen patients out of 250 studied suffered from acid base disorders. Gender distribution showed a higher percentage of male patients and the mean age was 70.5 ± 17.4 years. Double acid base disorders were the commonest disorders (34%) followed by metabolic acidosis (30%). Anion gap was calculated to further stratify metabolic acidosis and cases of diabetic ketoacidosis were the commonest in this category (47%). Other simple acid base disorders were relatively less frequent. Delta bicarbonate was calculated to unmask the superimposition of respiratory alkalosis or acidosis with metabolic acidosis and metabolic alkalosis. Though triple acid base disorders were noted in a small percentage of cases (05%), but were found to be the most complicated and challenging. Mixed acid base disorders were associated with high mortality. Conclusion: A large number of critically ill patients manifested acid base abnormalities over the full spectrum of these disorders. Mixed acid base disorders were

  10. Acid-base balance, dentinogenesis and dental caries:experimental studies in rats

    Bäckman, T. (Tuula)

    1999-01-01

    Abstract High-sucrose diet and metabolic acidosis have some similar effects on bone and they both reduce the formation of dentine. This series of experiments was conducted in order to get information about the effects of acidosis and alkalosis on dentine during primary dentinogenesis and also to ascertain if high-sucrose diet affects dentine formation via acidosis. Chronic metabolic acidosis (0.25 mol/L of NH4Cl in drinking water), chronic metabolic alkalosis (0.25 mol/L of NaHCO3 in drink...

  11. Antiretroviral agents and acid-base balance at delivery of the neonate

    P. El-Beitune

    2007-07-01

    Full Text Available Limited evidence is available regarding antiretroviral (ARV safety for uninfected infants exposed to these drugs in utero. Our objective was to determine if ARV administered to pregnant women is associated with decreasing umbilical arterial pH and base excess in uninfected infants. A prospective study was conducted on 57 neonates divided into three groups: ZDV group, born to mothers taking zidovudine (N = 20, triple therapy (TT group, born to mothers taking zidovudine + lamivudine + nelfinavir (N = 25, and control group (N = 12, born to uninfected mothers. Umbilical cord blood was used to determine umbilical artery gases. A test was performed to calculate the sample by comparing means by the unpaired one-tailed t-test, with a = 0.05 and ß = 20%, indicating the need for a sample of 18 newborn infants for the study groups to detect differences higher than 20%. The control and ARV groups were similar in gestational age, birth weight, and Apgar scores. Values of pH, pCO2, bicarbonate, and base excess in cord arterial blood obtained at delivery from the newborns exposed to TT were 7.23, 43.2 mmHg, 19.5 mEq/L, and -8.5 nmol/L, respectively, with no significant difference compared to the control and ZDV groups. We conclude that intrauterine exposure to ARV is not associated with a pathological decrease in umbilical arterial pH or base excess. While our data are reassuring, follow-up is still limited and needs to be continued into adulthood because of the possible potential for adverse effects of triple antiretroviral agents.

  12. Dietary Acid-Base Balance in Adolescent Sprint Athletes: A Follow-up Study

    Peter Clarys

    2011-02-01

    Full Text Available Sprinters are advised to include additional protein sources in their diet. Basal metabolism and vigorous physical activities generate hydrogen ions that need to be buffered. The present follow-up study estimates the dietary potential renal acid load (PRAL and net endogenous acid production (NEAP in adolescent sprint athletes. Seven-day food diaries and anthropometrics of 60 adolescent sprint athletes (mean age at start 14.7 ± 1.9 years were collected every six months over a three year period. Comparisons were made between athletes with a negative (PRAL(− versus positive PRAL (PRAL(+. For the entire sample, mean PRAL values of up to 6 mEq/day were slightly positive despite a relatively high protein intake of around 1.5 g/kg. The NEAP ranging between 42 and 46 mEq/day remained stable during the study period. Athletes with a PRAL(− (−8 to −10 mEq/day consumed significantly more fruit and fruit juice than athletes with a PRAL(+ (+9 to 14 mEq/day. Athletes with a PRAL(+ did not consume more meat, fish and poultry than athletes with a PRAL(−. Grains and dairy products were only discriminative between the two groups on one measurement occasion. Lowering the PRAL can be obtained by increasing the consumption of potatoes, fruits, vegetables and vegetable soup.

  13. Effect of acetaminophen on fetal acid-base balance in chorioamnionitis.

    Kirshon, B; Moise, K J; Wasserstrum, N

    1989-12-01

    The effect of antipyretic treatment with acetaminophen on fetal status was examined in eight laboring women febrile with chorioamnionitis. After a fetal heart rate tracing and scalp blood gas level were obtained near maximum maternal fever, a 650-mg acetaminophen suppository was administered. If the temperature remained greater than 101 degrees F, the dose was repeated in one to two hours. The fetal heart rate tracing was analyzed again after the mother's fever was reduced by acetaminophen. All patients delivered within four hours of the first dose. Umbilical artery blood gases were obtained at delivery. Significant improvements in the bicarbonate concentration and base deficit were noted at the time of delivery as compared to the scalp gas at the height of the maternal fever. The fetal heart rate tracings at the height of the maternal fever, characterized by tachycardia, poor variability and late decelerations, changed to a normal heart rate pattern without decelerations when the mother's fever was reduced. Hence, in the laboring gravida with chorioamnionitis, reducing maternal fever with acetaminophen improves fetal status and thereby may reduce the probability of cesarean section for fetal distress. PMID:2621737

  14. Acids and bases solvent effects on acid-base strenght

    Cox, Brian G

    2013-01-01

    Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

  15. Enhanced Acid/Base Catalysis in High Temperature Liquid Water

    Xiu Yang LU; Qi JING; Zhun LI; Lei YUAN; Fei GAO; Xin LIU

    2006-01-01

    Two novel and environmentally benign solvent systems, organic acids-enriched high temperature liquid water (HTLW) and NH3-enriched HTLW, were developed, which can enhance the reaction rate of acid/base-catalyzed organic reactions in HTLW. We investigated the decomposition of fructose in organic acids-enriched HTLW, hydrolysis of cinnamaldehyde and aldol condensation of phenylaldehyde with acetaldehyde in NH3-enriched HTLW. The experimental results demonstrated that organic acids-enriched or NH3-enriched HTLW can greatly accelerate acid/base-catalyzed organic reactions in HTLW.

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

    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…

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

    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. Acid-base transport in pancreas-new challenges

    Novak, Ivana; Haanes, Kristian Agmund; Wang, Jing

    2013-01-01

    to consider in pancreas are the proton pumps (H-K-ATPases), as well as the calcium-activated K and Cl channels, such as K3.1 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...

  19. Balanced Scorecard

    Ahonen, Tiina

    2015-01-01

    Tasapainotetun tuloskortin eli Balanced Scorecardin avulla organisaatiolla on mahdollisuus saada toiminnasta perinteisiä taloudellisia raportteja parempi kuva. Balanced Scorecard huomioi taloudellisten tunnuslukujen lisäksi myös asiakkaiden, sisäisten prosessien sekä oppimisen ja kasvun näkökulman. Tämän opinnäytetyön tavoitteena oli suunnitella suoritusmittaristo pk-yritykselle. Tutkimuksella haettiin Balance Scorecardin kautta vahvistusta ja tukea kohdeyrityksen sisäiseen laskentaan ja ...

  20. Study on acid- base disturbance in patients with posttraumatic multiple organ dysfunction syndrome

    2000-01-01

    Objective: To investigate the classification and incidence of acid-base disturbance (ABD) in the patients with post-traumatic multiple organ dysfunction syndrome (MODS). Methods: A total of 119 patients with MODS were examined with arterial blood gas analysis and serum electrolytes detection for 675 times in this study. Results: Different types of ABD existed in 647 times out of 675 times (95.9%) of blood-gas analyses. There were 270 times (41.7%) of simple ABD, 271 times (41.9%) of double ABD and 106 times (16.4%) of triple ABD. Among which, 404 times (62.4%) were in respiratory alkalosis (RAL), 332 times (51.3%) in metabolic acidosis (MA), 227 times (35.1% ) in metabolic alkalosis (MAL) and 167 times (25.8%) in respiratory acidosis (RA). In this study, 79 cases (66.4%) out of 119cases with MODS died from these kinds of ABD. Conclusions: It suggests that in the early stage of MODS, RAL with or without hypoxemia may exist, and later on, MA or even triple ABD may occur. In order to detect and correct the primary disorders as early as possible, it is important to keep the balance of hydrolyte. The treatment of primary diseases is also important.Disorders of acid-base balance were corrected according to pH standard values, anion gap (AG) and the potential [HCO3- ] were also calculated simultaneously. When pH was more than 7.50 or lower than 7.20, it is necessary to give drugs of acidity or alkalinity to the patients with ABD to maintain pH value within a normal range.

  1. Nucleic acid-based approaches to STAT inhibition.

    Sen, Malabika; Grandis, Jennifer R

    2012-10-01

    Silencing of abnormally activated genes can be accomplished in a highly specific manner using nucleic acid based approaches. The focus of this review includes the different nucleic acid based inhibition strategies such as antisense oligodeoxynucleotides, small interfering RNA (siRNA), dominant-negative constructs, G-quartet oligonucleotides and decoy oligonucleotides, their mechanism of action and the effectiveness of these approaches to targeting the STAT (signal transducer and activator of transcription) proteins in cancer. Among the STAT proteins, especially STAT3, followed by STAT5, are the most frequently activated oncogenic STATs, which have emerged as plausible therapeutic cancer targets. Both STAT3 and STAT5 have been shown to regulate numerous oncogenic signaling pathways including proliferation, survival, angiogenesis and migration/invasion. PMID:24058785

  2. Nucleic Acid-Based Nanodevices in Biological Imaging.

    Chakraborty, Kasturi; Veetil, Aneesh T; Jaffrey, Samie R; Krishnan, Yamuna

    2016-06-01

    The nanoscale engineering of nucleic acids has led to exciting molecular technologies for high-end biological imaging. The predictable base pairing, high programmability, and superior new chemical and biological methods used to access nucleic acids with diverse lengths and in high purity, coupled with computational tools for their design, have allowed the creation of a stunning diversity of nucleic acid-based nanodevices. Given their biological origin, such synthetic devices have a tremendous capacity to interface with the biological world, and this capacity lies at the heart of several nucleic acid-based technologies that are finding applications in biological systems. We discuss these diverse applications and emphasize the advantage, in terms of physicochemical properties, that the nucleic acid scaffold brings to these contexts. As our ability to engineer this versatile scaffold increases, its applications in structural, cellular, and organismal biology are clearly poised to massively expand. PMID:27294440

  3. Developing nucleic acid-based electrical detection systems

    Gabig-Ciminska Magdalena

    2006-03-01

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

  4. Advances in nucleic acid-based diagnostics of bacterial infections

    Barken, Kim Bundvig; Haagensen, Janus Anders Juul; Tolker-Nielsen, Tim

    2007-01-01

    Methods for rapid detection of infectious bacteria and antimicrobial-resistant pathogens have evolved significantly over the last decade. Many of the new procedures are nucleic acid-based and replace conventional diagnostic methods like culturing which is time consuming especially with fastidious...... of these pathogens is important to isolate patients and prevent further spreading of the diseases. Newly developed diagnostic procedures are superior with respect to turnaround time, sensitivity and specificity. Methods like multiplex real time PCR and different array-based technologies offer the possibility...

  5. Syntheses and characterizations of three acid-base supramolecular complexes

    Three acid-base compounds with supramolecular architectures, namely, (1,2-H2bdc)(dmt) (1), (trans-1,4-H2ccdc)0.5(phdat) (2) and (1,3-H2bdc)(phdat) (3) (1,2-H2bdc = 1,2-benzenedicarboxylic acid, trans-1, 4-H2ccdc = trans-1, 4-cyclohexanedicarboxylic acid, 1,3-H2bdc = 1,3-benzenedicarboxylic acid, dmt = 2,4-diamino-6-methyl-s-triazine, phdat = 2,4-diamino-6-phenyl-s-triazine) have been synthesized and characterized by IR spectra, elemental analyses, single-crystal X-ray diffractions and TGA. (author)

  6. Opuntia ficus indica (L.) Fruit Extract as Natural Indicator in Acid-Base Titration

    Manoj A. Suva

    2014-01-01

    In routine experiments synthetic indicators are the choice of acid base titrations. But there are some limitations like environmental pollution, availability and higher cost which leads to search for natural compounds as an acid base indicator was started. The present work highlights theexploit of the methanolic and aqueous extract of the fruit of Opuntia ficus indica plants as a natural acid base indicator in acid base titrations. Opuntia ficus indica plant was identified and fruits were was...

  7. Balance System

    1988-01-01

    TherEx Inc.'s AT-1 Computerized Ataxiameter precisely evaluates posture and balance disturbances that commonly accompany neurological and musculoskeletal disorders. Complete system includes two-strain gauged footplates, signal conditioning circuitry, a computer monitor, printer and a stand-alone tiltable balance platform. AT-1 serves as assessment tool, treatment monitor, and rehabilitation training device. It allows clinician to document quantitatively the outcome of treatment and analyze data over time to develop outcome standards for several classifications of patients. It can evaluate specifically the effects of surgery, drug treatment, physical therapy or prosthetic devices.

  8. Acid base catalyzed transesterification kinetics of waste cooking oil

    Jain, Siddharth; Sharma, M.P.; Rajvanshi, Shalini [Alternate Hydro Energy Centre, Indian Institute of Technology, Roorkee (India)

    2011-01-15

    The present study reports the results of kinetics study of acid base catalyzed two step transesterification process of waste cooking oil, carried out at pre-determined optimum temperature of 65 C and 50 C for esterification and transesterification process respectively under the optimum condition of methanol to oil ratio of 3:7 (v/v), catalyst concentration 1%(w/w) for H{sub 2}SO{sub 4} and NaOH and 400 rpm of stirring. The optimum temperature was determined based on the yield of ME at different temperature. Simply, the optimum concentration of H{sub 2}SO{sub 4} and NaOH was determined with respect to ME Yield. The results indicated that both esterification and transesterification reaction are of first order rate reaction with reaction rate constant of 0.0031 min{sup -1} and 0.0078 min{sup -1} respectively showing that the former is a slower process than the later. The maximum yield of 21.50% of ME during esterification and 90.6% from transesterification of pretreated WCO has been obtained. This is the first study of its kind which deals with simplified kinetics of two step acid-base catalyzed transesterification process carried under the above optimum conditions and took about 6 h for complete conversion of TG to ME with least amount of activation energy. Also various parameters related to experiments are optimized with respect to ME yield. (author)

  9. Acid-base actuation of [c2]daisy chains.

    Fang, Lei; Hmadeh, Mohamad; Wu, Jishan; Olson, Mark A; Spruell, Jason M; Trabolsi, Ali; Yang, Ying-Wei; Elhabiri, Mourad; Albrecht-Gary, Anne-Marie; Stoddart, J Fraser

    2009-05-27

    A versatile synthetic strategy, which was conceived and employed to prepare doubly threaded, bistable [c2]daisy chain compounds, is described. Propargyl and 1-pentenyl groups have been grafted onto the stoppers of [c2]daisy chain molecules obtained using a template-directed synthetic protocol. Such [c2]daisy chain molecules undergo reversible extension and contraction upon treatment with acid and base, respectively. The dialkyne-functionalized [c2]daisy chain (AA) was subjected to an [AA+BB] type polymerization with an appropriate diazide (BB) to afford a linear, mechanically interlocked, main-chain polymer. The macromolecular properties of this polymer were characterized by chronocoulometry, size exclusion chromatography, and static light-scattering analysis. The acid-base switching properties of both the monomers and the polymer have been studied in solution, using (1)H NMR spectroscopy, UV/vis absorption spectroscopy, and cyclic voltammetry. The experimental results demonstrate that the functionalized [c2]daisy chains, along with their polymeric derivatives, undergo quantitative, efficient, and fully reversible switching processes in solution. Kinetics measurements demonstrate that the acid/base-promoted extension/contraction movements of the polymeric [c2]daisy chain are actually faster than those of its monomeric counterpart. These observations open the door to correlated molecular motions and to changes in material properties. PMID:19419175

  10. [Practical approach to complex acid-base disorders using a slide rule].

    Rives, E; Grimaud, D

    1986-01-01

    Diagnosis of mixed acid-base disturbances is often difficult. Nowadays it depends on biochemical and statistical interpretation, coupled with clinical data. The acid-base slide-rule is a useful tool to carry out this five step procedure, which it simplifies, giving rapidly at the patient's bed-side an objective support for the diagnosis of acid-base disturbances. PMID:3777572

  11. Acid-base interactions in microbial adhesion to hexadecane and chloroform

    Bos, R; Busscher, HJ; Geertsema-Doornbusch, GI; Van Der Mei, HC; Mittal, KL

    2000-01-01

    Acid-base interactions play an important role in adhesion, including microbial adhesion to surfaces. Qualitatively acid-base interactions in microbial adhesion can be demonstrated by comparing adhesion to hexadecane (a negatively charged interface in aqueous solutions, unable to exert acid-base inte

  12. Balance (or Vestibular) Rehabilitation

    ... for the Public / Hearing and Balance Balance (or Vestibular) Rehabilitation Audiologic (hearing), balance, and medical diagnostic tests help indicate whether you are a candidate for vestibular (balance) rehabilitation. Vestibular rehabilitation is an individualized balance ...

  13. Balancing Risk

    Nygaard, Lene; Rossen, Camilla Blach; Buus, Niels

    2015-01-01

    This study explored how eight pregnant women diagnosed with depression managed the decision whether or not to take antidepressants during pregnancy. In total, 11 interviews were conducted and analysed by means of constructivist grounded theory. The major category constructed was Balancing risk......, with two minor categories: Assessing depression and antidepressants and Evaluating the impact of significant others. The participants tried to make the safest decision, taking all aspects of their life into consideration. They described successful decision-making in the context of managing social norms...

  14. Social Balance Theory

    Hokky Situngkir; Deni Khanafiah

    2004-01-01

    We construct a model based on social balance theory proposed by Fritz Heider to analyze the interpersonal network among social agents. The model of social balance theory provides us an interesting tool to see how a social group evolves to the possible balance state. We introduce the balance index that can be used to measure social balance in macro structure level (global balance index) or in micro structure (local balance index) to see how the local balance index influences the global balance...

  15. FERTILIZATION OF VINE BY A 5-AMINOLEVULINIC ACID-BASED FERTILIZER AND ITS PROFITABILITY

    VLADIMR IMANSK

    2013-03-01

    Full Text Available In this work we investigated the effect of different doses of NPKS fertilizer added into the soil for nutrient contents in the soil, as well as the quantity and quality of grapes. During the vegetation of the vine, we tested the 5-aminolevulinic acid-based fertilizer (ALA. We summarize that higher doses of fertilizer added into soil caused higher amounts of available nutrients. During the vegetation of the vine an increase of ALA had a positive effect on the optimal balance of nutrients. Fertilization also increased the grape-vine yield, with the strongest effect (by 68% observed due to the application of ALA during the vegetation period of the vine. Added fertilizers had a statistically significant influence on decreased sugar concentration in the grape-vine however the addition of fertilizer into the soil, mainly the application of ALA during vegetation of the vine (by 57% had a positive effect on increase of the total content of sugar in the grape-vine, produced on 1 hectare. The year had a significant influence on the economical evaluation.

  16. Acid-base transport in pancreas – new challenges

    Ivana eNovak

    2013-12-01

    Full Text Available 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 (HCO3- 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 HCO3- 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 signalling, 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.

  17. Linear and nonlinear optical properties of nucleic acid bases

    Alparone, Andrea

    2013-01-01

    Electronic and vibrational (hyper)polarizabilities of neutral nucleic acid bases (uracil, thymine, cytosine, adenine, hypoxanthine and guanine) were determined using Hartree-Fock, correlated MPn (n = 2, 4), CCSD and DFT (B3LYP, B97-1, CAM-B3LYP) methods. The computations were performed in gaseous and aqueous phases for the most stable tautomeric forms. Frequency-dependent second-order hyperpolarizabilities were calculated for the OKE, IDRI, EFISHG and THG nonlinear optical processes at the wavelength of 1064 nm. The results show that the average electronic polarizabilities increase in the order uracil guanine. This order is also maintained for the electronic hyperpolarizabilities, with the inversion between cytosine and thymine. The response electric properties for the tautomers are almost similar to each other, whereas group substitution and solvation effects are much more significant. Among the DFT methods, the long-range corrected CAM-B3LYP functional gives the better performances, reproducing satisfactorily the correlated ab initio (hyper)polarizability data.

  18. [Development of Nucleic Acid-Based Adjuvant for Cancer Immunotherapy].

    Kobiyama, Kouji; Ishii, Ken J

    2015-09-01

    Since the discovery of the human T cell-defined tumor antigen, the cancer immunotherapy field has rapidly progressed, with the research and development of cancer immunotherapy, including cancer vaccines, being conducted actively. However, the disadvantages of most cancer vaccines include relatively weak immunogenicity and immune escape or exhaustion. Adjuvants with innate immunostimulatory activities have been used to overcome these issues, and these agents have been shown to enhance the immunogenicity of cancer vaccines and to act as mono-therapeutic anti-tumor agents. CpG ODN, an agonist for TLR9, is one of the promising nucleic acid-based adjuvants, and it is a potent inducer of innate immune effector functions. CpG ODN suppresses tumor growth in the absence of tumor antigens and peptide administration. Therefore, CpG ODN is expected to be useful as a cancer vaccine adjuvant as well as a cancer immunotherapy agent. In this review, we discuss the potential therapeutic applications and mechanisms of CpG ODN for cancer immunotherapy. PMID:26469159

  19. Temperatura e alterações no equilíbrio ácido-base de pacientes submetidos à cirurgia cardíaca com circulação extracorpórea, sob normotermia e hipotermia Temperatura y alteraciones en el equilibrio ácido-base de pacientes sometidos a cirugía cardíaca con circulación extracorpórea, bajo normotermia e hipotermia Temperature and acid-base balance in coronary bypass grafting with cardiopulmonary bypass, under hypothermia and normothermia

    Hugo Leonardo de Moura Luz

    2002-04-01

    operados sobre hipotermia, sugiriendo que el transporte de oxígeno para la periferia no fue adecuado durante el período de observación propuesto. La disminución de la temperatura, aun cuando discreta, parece no haber conferido el grado de protección celular esperada al flujo sanguíneo de la CEC.BACKGROUND AND OBJECTIVES: Cardiopulmonary bypass (CPB is related to several changes in normal physiology. The multiple causes of these changes interact and are a potential risk for postoperative organic dysfunction. This study aimed at investigating changes in acid-base and metabolic balance during cardiopulmonary bypass with hypothermia and at comparing them to those observed in patients submitted to normothermal cardiopulmonary bypass. METHODS: Participated in this study 30 adult patients of both genders, aged 41 to 78 years, scheduled for coronary bypass grafting with CPB, under normothermia or hypothermia. The following parameters were evaluated: hemoglobin and blood gases concentration, pH, bicarbonate, base excess, anion gap, lactate ion, tissue oxygenation parameters and flow and systemic vascular resistance. RESULTS: There were no statistically significant differences in arterial pH, arterial bicarbonate, Na+ and Cl- plasma concentrations, anion gap, carbon dioxide partial pressure and arterial oxygen content between Normothermia and Hypothermia Groups. A time-effect was observed for all variables except for base excess and anion gap. Base excess and K+ concentration were lower in the hypothermia group. Serum lactate increased in both groups when comparing time before CPB to after CPB, with higher levels in the hypothermia group. CONCLUSIONS: Mild hypothermia does not seem to substantially change acid-base balance as compared to normal temperature during CPB. Plasma lactate, however, has significantly increased in patients under hypothermia, suggesting inadequate oxygen transport to periphery during the proposed observation period. Low temperature, although mild, does

  20. Acid-base behavior in hydrothermal processing of wastes. 1998 annual progress report

    'A new technology, hydrothermal oxidation (also called supercritical water oxidation), is being developed to treat high level nuclear wastes. Nitrates are reduced to nitrogen; furthermore, phosphates, alumina sludge, and chromium are solubilized, and the sludge is reconstituted as fine oxide particles. A major obstacle to development of this technology has been a lack of scientific knowledge of chemistry in hydrothermal solution above 350 C, particularly acid-base behavior, and transport phenomena, which is needed to understand corrosion, metal-ion complexation, and salt precipitation and recovery. The objective is to provide this knowledge with in-situ UV-vis spectroscopic measurements and fully molecular computer simulation. A major objective of the experimental studies has been to determine the equilibria for Cr(VI) up to 420 C as this is a key species to be removed from nuclear wastes. A wide range of concentrations of KOH and perchloric acid were utilized to manipulate the acid-base equilibria and to understand the effects of ion solvation and ion pairing. The second system is the equilibria between nitric acid, nitrous acid, nitrogen dioxide, nitrite and nitrate ions and oxygen. For both of these systems, chemical equilibria has not been measured previously in hydrothermal solution at these temperatures. On the theoretical side, the authors have focused on the study of the transport properties of aqueous ions in supercritical water. The motivation for these studies is two fold. First, although transport coefficients are fundamental to solution chemistry reaction rates, the behavior of such transport properties over wide ranges of density and temperature are not well established experimentally, particularly at the densities typically of interest (< 0.5 g/cc). Second, due to practical challenges, ionic association equilibria in SCW is typically accessed via measurements of conductivity followed by analysis through a theoretical model that incorporates ion

  1. Spontaneous formation of biocompatible vesicles in aqueous mixtures of amino acid-based cationic surfactants and SDS/SDBS.

    Shome, Anshupriya; Kar, Tanmoy; Das, Prasanta K

    2011-02-01

    The spontaneous formation of vesicles by six amino acid-based cationic surfactants and two anionic surfactants (sodium dodecylbenzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS)) is reported. The head-group structure of the cationic surfactants is minutely altered to understand their effect on vesicle formation. To establish the regulatory role of the aromatic group in self-aggregation, both aliphatic and aromatic side-chain-substituted amino acid-based cationic surfactants are used. The presence of aromaticity in any one of the constituents favors the formation of vesicles by cationic/anionic surfactant mixtures. The formation of vesicles is primarily dependent on the balance between the hydrophobicity and hydrophilicity of both cationic and anionic surfactants. Vesicle formation is characterized by surface tension, fluorescence anisotropy, transmission electron microscopy, dynamic light scattering, and phase diagrams. These vesicles are thermally stable up to 65 °C, determined by temperature-dependent fluorescence anisotropy. According to the MTT assay, these catanionic vesicles are nontoxic to NIH3T3 cells, thus indicating their wider applicability as delivery vehicles to cells. Among the six cationic surfactants examined, tryptophan- and tyrosine-based surfactants have the ability to reduce HAuCl(4) to gold nanoparticles (GNPs), which is utilized to obtain in-situ-synthesized GNPs entrapped in vesicles without the need for any external reducing agent. PMID:21275029

  2. Pulmonary gas exchange and acid-base state at 5,260 m in high-altitude Bolivians and acclimatized lowlanders

    Wagner, Hans Peter; Araoz, Mauricio; Boushel, Robert Christopher;

    2002-01-01

    Pulmonary gas exchange and acid-base state were compared in nine Danish lowlanders (L) acclimatized to 5,260 m for 9 wk and seven native Bolivian residents (N) of La Paz (altitude 3,600-4,100 m) brought acutely to this altitude. We evaluated normalcy of arterial pH and assessed pulmonary gas...... exchange and acid-base balance at rest and during peak exercise when breathing room air and 55% O2. Despite 9 wk at 5,260 m and considerable renal bicarbonate excretion (arterial plasma HCO3- concentration = 15.1 meq/l), resting arterial pH in L was 7.48 +/- 0.007 (significantly greater than 7...

  3. Balanced Scorecard

    Kytka, Roman

    2008-01-01

    V současnosti se podniky setkávají s řadou přístupů k řízení společností a velmi častými pojícími prvky bývají zejména náklady, efektivita a výkonnost. Z nepřeberné řady nástrojů k řízení společností určených tato práce blíže seznamuje s metodikou Balanced Scorecard (BSC), koncepčním rámcem ITIL a metodikou Cobit. Jednotlivě zde jsou představeny dílčí metodiky a rámce. Míra tohoto seznámení je úměrná potřebám práce, tzn. není cílem představit ITIL či Cobit úplně detailně. Naopak zde jsou podc...

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

    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…

  5. Key Roles of Lewis Acid-base Pairs on ZnxZryOz in Direct Ethanol/Acetone to Isobutene Conversion

    Sun, Junming; Baylon, Rebecca A.; Liu, Changjun; Mei, Donghai; Martin, Kevin J.; Venkitasubramanian, Padmesh; Wang, Yong

    2016-01-20

    The effects of surface acidity on the cascade ethanol-to-isobutene conversion were studied using ZnxZryOz catalysts. The ethanol-to-isobutene reaction was found to be limited by the secondary reaction of the key intermediate, acetone, namely the acetone-to-isobutene reaction. Although the catalysts with coexisting Brønsted acidity could catalyze the rate-limiting acetone-to-isobutene reaction, the presence of Brønsted acidity is also detrimental. First, secondary isobutene isomerization is favored, producing a mixture of butene isomers. Second, undesired polymerization and coke formation prevail, leading to rapid catalyst deactivation. Most importantly, both steady-state and kinetic reaction studies as well as FTIR analysis of adsorbed acetone-d6 and D2O unambiguously showed that a highly active and selective nature of balanced Lewis acid-base pairs was masked by the coexisting Brønsted acidity in the aldolization and self-deoxygenation of acetone to isobutene. As a result, ZnxZryOz catalysts with only Lewis acid-base pairs were discovered, on which nearly a theoretical selectivity to isobutene (~88.9%) was successfully achieved, which has never been reported before. Moreover, the absence of Brønsted acidity in such ZnxZryOz catalysts also eliminates the side isobutene isomerization and undesired polymerization/coke reactions, resulting in the production of high purity isobutene with significantly improved catalyst stability (< 2% activity loss after 200 h time-on-stream). This work not only demonstrates a balanced Lewis acid-base pair for the highly active and selective cascade ethanol-to-isobutene reaction, but also sheds light on the rational design of selective and robust acid-base catalyst for C-C coupling via aldolization reaction.

  6. [Materno-fetal acid-base equilibrium evaluation in parturients submitted to ketamine anesthesia (author's transl)].

    Mauad Filho, F; Meirelles, R S

    1975-01-01

    In the present work ketamine was used as anesthetic during the labor in order to evaluate the effect of this anesthetic on the binominal fetus-mother. Two groups of parturients and their fetuses, were studied: 1) The experimental group, with 22 parturients and their fetuses submitted to ketamine anesthesia during the labord, and 2) The control group, with 20 parturients and their fetuses without any analgesic treatment during the labor. In 20 cases of the experimental group the anesthetic was injected during the delivery labor and the other two just before it. It were evaluated in the mother's blood the biochemical parameters of the acid-base balance and others collateral effects of the anesthesia; on the fetus's side the same parameters also and the cardiac frequency. The newborn were evaluated by Apgar Score during the first and fifth minutes of life. The incidence of the spontaneous delivery in the experimental group, was 78%; in 22% of these patients the forceps of relief was used. In 22 cases in which Ketamine was applied it were observed, the following events: elevation of the blood pressure (50%), perineum rigidness (18%), dreams and or hallucinations (18%), increase of the cardiac frequency (9%), apneia (4%) and nausea (4%). It was also observed an increase of uterine tonus an abolishment of abdominal press during the delivery labor, studied through the uterine electromyography register. It was noted after the Ketamine application a fall in the pH of the maternal peripherical venous blood, fetal skull blood and the pH of the blood of the umbilical vein. 22% of the newborns, from the experimental group, presented a depression in the first minute of life (Apgar less than or equals to 6). The pCO2 values in the blood of the umbilical artery were higher in the experimental group than in the control one. PMID:1241148

  7. Acute incremental endurance performance and explosive strength training period : muscle activity, acid-base balance and hormonal responses

    Saikko, Ville

    2015-01-01

    Johdanto. Akuutin kestävyys- ja voimaharjoituksen fysiologiset vasteet ilmenevät luurankolihaksissa, hengitys- ja verenkiertoelimistössä, sekä endokriinisessa että immuunijärjestelmässä. Nämä vasteet voivat heikentää suorituskykyä, ja esimerkiksi happo-emästasapaino on tarkoin säädelty negatiivisten seurausten varalta. Lihasten toimintaa voidaan tutkia elektromyografialla (EMG), ja nykyään on myös mahdollista käyttää tekstiilielektrodeja, jotka mahdollistavat lihasryhmien sähköisen aktiivisuu...

  8. Balanced Permutation Codes

    Gabrys, Ryan; Milenkovic, Olgica

    2016-01-01

    Motivated by charge balancing constraints for rank modulation schemes, we introduce the notion of balanced permutations and derive the capacity of balanced permutation codes. We also describe simple interleaving methods for permutation code constructions and show that they approach capacity

  9. Dizziness and Balance

    AUDIOLOGY Dizziness and Balance Inform ation Seri es Our balance system helps us walk, run, and move ... known as nystagmus) • Complaints of vertigo or dizziness Audiology Information Series © ASHA 2015 10802 • Balance dysfunction • Difficulty ...

  10. Properties investigation of sulfonated poly(ether ether ketone)/polyacrylonitrile acid-base blend membrane for vanadium redox flow battery application.

    Li, Zhaohua; Dai, Wenjing; Yu, Lihong; Liu, Le; Xi, Jingyu; Qiu, Xinping; Chen, Liquan

    2014-11-12

    Acid-base blend membrane prepared from sulfonated poly(ether ether ketone) (SPEEK) and polyacrylonitrile (PAN) was detailedly evaluated for vanadium redox flow battery (VRFB) application. SPEEK/PAN blend membrane exhibited dense and homogeneous cross-section morphology as scanning electron microscopy and energy-dispersive X-ray spectroscopy images show. The acid-base interaction of ionic cross-linking and hydrogen bonding between SPEEK and PAN could effectively reduce water uptake, swelling ratio, and vanadium ion permeability, and improve the performance and stability of blend membrane. Because of the good balance of proton conductivity and vanadium ion permeability, blend membrane with 20 wt % PAN (S/PAN-20%) showed higher Coulombic efficiency (96.2% vs 91.1%) and energy efficiency (83.5% vs 78.4%) than Nafion 117 membrane at current density of 80 mA cm(-2) when they were used in VRFB single cell. Besides, S/PAN-20% membrane kept a stable performance during 150 cycles at current density of 80 mA cm(-2) in the cycle life test. Hence the SPEEK/PAN acid-base blend membrane could be used as promising candidate for VRFB application. PMID:25315399

  11. Recent advances in understanding trans-epithelial acid-base regulation and excretion mechanisms in cephalopods

    Hu, Marian Y.; Hwang, Pung-Pung; Tseng, Yung-Che

    2015-01-01

    Cephalopods have evolved complex sensory systems and an active lifestyle to compete with fish for similar resources in the marine environment. Their highly active lifestyle and their extensive protein metabolism has led to substantial acid-base regulatory abilities enabling these organisms to cope with CO2 induced acid-base disturbances. In convergence to teleost, cephalopods possess an ontogeny-dependent shift in ion-regulatory epithelia with epidermal ionocytes being the major site of embry...

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

    Herfen, K; Bostedt, H

    1999-06-01

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

  13. Human Balance System

    ... Rated Nonprofit! Volunteer. Donate. Review. The Human Balance System Good balance is often taken for granted. Good ... soft, slippery, or uneven). Input from the vestibular system Sensory information about motion, equilibrium, and spatial orientation ...

  14. Random walk and balancing

    Borg, F G

    2004-01-01

    Presents a minireview of topics concerned with balancing in quiet (bipedal) standing, and balancing of a stick. In the focus is the apparent stochastic nature of the swaying of the human inverted pendulum.

  15. Skylab water balance analysis

    Leonard, J. I.

    1977-01-01

    The water balance of the Skylab crew was analyzed. Evaporative water loss using a whole body input/output balance equation, water, body tissue, and energy balance was analyzed. The approach utilizes the results of several major Skylab medical experiments. Subsystems were designed for the use of the software necessary for the analysis. A partitional water balance that graphically depicts the changes due to water intake is presented. The energy balance analysis determines the net available energy to the individual crewman during any period. The balances produce a visual description of the total change of a particular body component during the course of the mission. The information is salvaged from metabolic balance data if certain techniques are used to reduce errors inherent in the balance method.

  16. Theoretical study of the influence of ribose on the proton transfer phenomenon of nucleic acid bases

    The first comprehensive theoretical study of ribose's effects on the behavior of proton transfer of nucleic acid base is presented. The specific hydrogen bonding of the ribose hydroxyls plays a very important role in the stabilization of the structure of ribonucleoside. Nine stable uridine conformations have been reported. The intermolecular proton transfer of the isolated, monohydrated uridine complexes in three different regions were extensively explored on the basis of density functional theory at the B3LYP/6-31+G* level. With the introduction of the ribose, not only the structural parameters of the nucleic acid bases changed, but also the energy barriers of the proton transfer process changed. Furthermore, changes of the electron distributions of the molecular orbital of the nucleic acid bases were also analyzed by NBO analysis. Consideration of the ribose's influence represents a much more real situation in the RNA

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

    Osther, Palle J

    2006-01-01

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

  18. Polarization-balanced beamsplitter

    Decker, D.E.

    1998-02-17

    A beamsplitter assembly is disclosed that includes several beamsplitter cubes arranged to define a plurality of polarization-balanced light paths. Each polarization-balanced light path contains one or more balanced pairs of light paths, where each balanced pair of light paths includes either two transmission light paths with orthogonal polarization effects or two reflection light paths with orthogonal polarization effects. The orthogonal pairing of said transmission and reflection light paths cancels polarization effects otherwise caused by beamsplitting. 10 figs.

  19. The in Silico Insight into Carbon Nanotube and Nucleic Acid Bases Interaction

    Karimi, Ali Asghar; Ghalandari, Behafarid; Tabatabaie, Seyed Saleh; Farhadi, Mohammad

    2016-01-01

    Background To explore practical applications of carbon nanotubes (CNTs) in biomedical fields the properties of their interaction with biomolecules must be revealed. Recent years, the interaction of CNTs with biomolecules is a subject of research interest for practical applications so that previous research explored that CNTs have complementary structure properties with single strand DNA (ssDNA). Objectives Hence, the quantum mechanics (QM) method based on ab initio was used for this purpose. Therefore values of binding energy, charge distribution, electronic energy and other physical properties of interaction were studied for interaction of nucleic acid bases and SCNT. Materials and Methods In this study, the interaction between nucleic acid bases and a (4, 4) single-walled carbon nanotube (SCNT) were investigated through calculations within quantum mechanics (QM) method at theoretical level of Hartree-Fock (HF) method using 6-31G basis set. Hence, the physical properties such as electronic energy, total dipole moment, charge distributions and binding energy of nucleic acid bases interaction with SCNT were investigated based on HF method. Results It has been found that the guanine base adsorption is bound stronger to the outer surface of nanotube in comparison to the other bases, consistent with the recent theoretical studies. In the other words, the results explored that guanine interaction with SCNT has optimum level of electronic energy so that their interaction is stable. Also, the calculations illustrated that SCNT interact to nucleic acid bases by noncovalent interaction because of charge distribution an electrostatic area is created in place of interaction. Conclusions Consequently, small diameter SCNT interaction with nucleic acid bases is noncovalent. Also, the results revealed that small diameter SCNT interaction especially SCNT (4, 4) with nucleic acid bases can be useful in practical application area of biomedical fields such detection and drug delivery.

  20. Opuntia ficus indica (L. Fruit Extract as Natural Indicator in Acid-Base Titration

    Manoj A. Suva

    2014-03-01

    Full Text Available In routine experiments synthetic indicators are the choice of acid base titrations. But there are some limitations like environmental pollution, availability and higher cost which leads to search for natural compounds as an acid base indicator was started. The present work highlights theexploit of the methanolic and aqueous extract of the fruit of Opuntia ficus indica plants as a natural acid base indicator in acid base titrations. Opuntia ficus indica plant was identified and fruits were washed and cleaned by distilled water, grinded by a mechanical blender and soaked in 50ml methanol for 48 hours and then triturated in mortal and pestle and the resulting solution were filtered through muslin cloth. The resulted methanolic extract and aqueous extract which was prepared by heating fruits in water for half an hour and filtered used as natural indicator foracidimetry and alkalimetry. For each type of acid base titrations t-value and standard deviation were calculated from results obtained. Natural indicator is easy to prepare, easily available and have no toxic effects and promising results were obtained when it was tested against standard synthetic indicators. Titration shows sharp colour change at the equivalence point. The equivalence points (end points obtained by the fruit extract correlate with the equivalence points obtained by standard indicators. In strong acid and strong base titration, the results obtained in the fruit's extract matched with the results obtained by standard indicator. Hence, natural indicator is found to be a very useful, readily available, nonhazardous, economical, simple to prepare and accurate for the acid-base titrations.

  1. Coaching for Balance.

    Larson, Bonnie

    2001-01-01

    Discusses coaching for balance the integration of the whole self: physical (body), intellectual (mind), spiritual (soul), and emotional (heart). Offers four ways to identify problems and tell whether someone is out of balance and four coaching techniques for creating balance. (Contains 11 references.) (JOW)

  2. Studies on synthesis and property of novel acid-base proton exchange membranes

    Yong Fang Liang; Hai Yan Pan; Xiu Ling Zhu; Yao Xia Zhang; Xi Gao Jian

    2007-01-01

    Sulfonated poly(phthalazinone)s (SPPENK, SPPESK and SPPBEK) were prepared by direct polymerization reaction from sulfonated monomers. The novel acid-base membranes were composed of sulfonated polymers as the acidic compounds, and polyetherimide (PEI) as the basic compounds, casting from their N-methylpyrrolidone (NMP) solution directly onto clean glass plates at 60 ℃ aiming at enhancing membrane toughness and other relative properties. The resulted acid-base composite membranes had excellent resistance to swelling, thermo-stability, hydrolysis resistance and oxidative resistance properties with highly ion-exchange capacity (IEC).

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

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

    2014-09-01

    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.

  4. Calculating acid-base and oxygenation status during COPD exacerbation using mathematically arterialised venous blood

    Rees, Stephen Edward; Rychwicka-Kielek, Beate A; Andersen, Bjarne F;

    2012-01-01

    Abstract Background: Repeated arterial puncture is painful. A mathematical method exists for transforming peripheral venous pH, PCO2 and PO2 to arterial eliminating the need for arterial sampling. This study evaluates this method to monitor acid-base and oxygenation during admission for exacerbat......Abstract Background: Repeated arterial puncture is painful. A mathematical method exists for transforming peripheral venous pH, PCO2 and PO2 to arterial eliminating the need for arterial sampling. This study evaluates this method to monitor acid-base and oxygenation during admission...

  5. Acid-base regulation in tadpoles of Rana catesbeiana exposed to environmental hypercapnia

    Busk, Morten; Larsen, Erik Hviid; Jensen, Frank B.

    1997-01-01

    Tadpoles of Rana catesbeiana were exposed to different levels of environmental hypercapnia. The acid-base regulatory response differed from that in adult amphibians in showing a high degree of pH compensation in the extracellular fluid (65-85%) and complete compensation in the intracellular fluid......). It is suggested that the large bicarbonate efflux from the animal is a consequence of the dissolution of CaCO3 stores and the delayed adjustment of bicarbonate-retaining mechanisms. Re-exposure of tadpoles to hypercapnia after 1-3 weeks of normocapnic recovery only affected transepithelial fluxes of acid-base...

  6. Nucleic Acid-based Detection of Bacterial Pathogens Using Integrated Microfluidic Platform Systems

    Carl A. Batt

    2009-05-01

    Full Text Available The advent of nucleic acid-based pathogen detection methods offers increased sensitivity and specificity over traditional microbiological techniques, driving the development of portable, integrated biosensors. The miniaturization and automation of integrated detection systems presents a significant advantage for rapid, portable field-based testing. In this review, we highlight current developments and directions in nucleic acid-based micro total analysis systems for the detection of bacterial pathogens. Recent progress in the miniaturization of microfluidic processing steps for cell capture, DNA extraction and purification, polymerase chain reaction, and product detection are detailed. Discussions include strategies and challenges for implementation of an integrated portable platform.

  7. DYMAC digital electronic balance

    The Dynamic Materials Accountability (DYMAC) System at LASL integrates nondestructive assay (NDA) instruments with interactive data-processing equipment to provide near-real-time accountability of the nuclear material in the LASL Plutonium Processing Facility. The most widely used NDA instrument in the system is the DYMAC digital electronic balance. The DYMAC balance is a commercial instrument that has been modified at LASL for weighing material in gloveboxes and for transmitting the weight data directly to a central computer. This manual describes the balance components, details the LASL modifications, reviews a DYMAC measurement control program that monitors balance performance, and provides instructions for balance operation and maintenance

  8. The Balanced Company

    involved in both the creation and recreation of balanced relationships. Chapters in The Balanced Company ask and provide answers to questions about corporately responsible and ethically driven balanced decision making, such as: • How can a company and its stakeholders identify what should be taken into...... changes in their environments. Communication specialists need to make balanced decisions which take the different value systems and assumptions of stakeholders into consideration. Change specialists need to balance the need for continuity and change. Managers need to make balanced decisions about whether...... in consumers' and other stakeholder's eyes. Leaders also have to acknowledge that there are times when organizations have to be taken out of balance, since it is necessary to 'unfreeze' existing relationships in organizations during change. Therefore, there are decision and organizing processes...

  9. The scaled-charge additive force field for amino acid based ionic liquids

    Fileti, E. E.; Chaban, V. V.

    2014-01-01

    Ionic liquids (ILs) constitute an emerging research field. New ILs involve more and more organic and inorganic ions. Amino acid based ILs (AAILs) represent a specific interest due to their evolutional connection to proteins. We report a new non-polarizable force field (FF) for the eight AAILs...

  10. Design, synthesis and structure of new potential electrochemically active boronic acid-based glucose sensors

    Norrild, Jens Chr.; Søtofte, Inger

    2002-01-01

    In the course of our investigations on new boronic acid based carbohydrate sensors three new boronic acids 3, 7 and 11 containing a ferrocene moiety were synthesised. Their design includes an intramolecular B-N bonding motif in order to facilitate binding at physiological pH. We report...

  11. Osmoregulation and acid base regulation of the Asian Horseshoe crab Carcinoscorpius rotundicauda

    Wetter, M.; Cong, N.; Nielsen, Thomas;

    2008-01-01

    to hypercapnia (5% CO2) was partially restored by increased HC = 3-levels in the haemolymph. The degree of compensation did not differ between individuals that had been held at high or low salinity suggesting that the availability of acid-base relevant ions plays a minor role in this response....

  12. Effect of benzoic acid supplementation on acid-base status and mineralmetabolism in catheterized growing pigs

    Nørgaard, Jan Værum; Fernández, José Adalberto; Sørensen, Kristina Ulrich;

    2010-01-01

    Benzoic acid (BA) in diets for growing pigs results in urinary acidification and reduced ammonia emission. The objective was to study the impact of BA supplementation on the acid-base status and mineral metabolism in pigs. Eight female 50-kg pigs, fitted with a catheter in the abdominal aorta, were...

  13. Determining surface areas of marine alga cells by acid-base titration method.

    Wang, X; Ma, Y; Su, Y

    1997-09-01

    A new method for determining the surface area of living marine alga cells was described. The method uses acid-base titration to measure the surface acid/base amount on the surface of alga cells and uses the BET (Brunauer, Emmett, and Teller) equation to estimate the maximum surface acid/base amount, assuming that hydrous cell walls have carbohydrates or other structural compounds which can behave like surface Brönsted acid-base sites due to coordination of environmental H2O molecules. The method was applied to 18 diverse alga species (including 7 diatoms, 2 flagellates, 8 green algae and 1 red alga) maintained in seawater cultures. For the species examined, the surface areas of individual cells ranged from 2.8 x 10(-8) m2 for Nannochloropsis oculata to 690 x 10(-8) m2 for Dunaliella viridis, specific surface areas from 1,030 m2.g-1 for Dunaliella salina to 28,900 m2.g-1 for Pyramidomonas sp. Measurement accuracy was 15.2%. Preliminary studies show that the method may be more promising and accurate than light/electron microscopic measurements for coarse estimation of the surface area of living algae. PMID:9297794

  14. Analysis and Identification of Acid-Base Indicator Dyes by Thin-Layer Chromatography

    Clark, Daniel D.

    2007-01-01

    Thin-layer chromatography (TLC) is a very simple and effective technique that is used by chemists by different purposes, including the monitoring of the progress of a reaction. TLC can also be easily used for the analysis and identification of various acid-base indicator dyes.

  15. Isoelectric Point, Electric Charge, and Nomenclature of the Acid-Base Residues of Proteins

    Maldonado, Andres A.; Ribeiro, Joao M.; Sillero, Antonio

    2010-01-01

    The main object of this work is to present the pedagogical usefulness of the theoretical methods, developed in this laboratory, for the determination of the isoelectric point (pI) and the net electric charge of proteins together with some comments on the naming of the acid-base residues of proteins. (Contains 8 figures and 4 tables.)

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

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

    1994-01-01

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

  17. Investigation of surfactant mediated acid-base charging of mineral oxide particles dispersed in apolar systems.

    Gacek, Matthew M; Berg, John C

    2012-12-21

    The current work examines the role of acid-base properties on particle charging in apolar media. Manipulating the polarity and magnitude of charge in such systems is of growing interest to a number of applications. A major hurdle to the implementation of this technology is that the mechanism(s) of particle charging remain a subject of debate. The authors previously conducted a study of the charging of a series of mineral oxide particles dispersed in apolar systems that contained the surfactant AOT. It was observed that there was a correlation between the particle electrophoretic mobility and the acid-base nature of the particle, as characterized by aqueous point of zero charge (PZC) or the isoelectric point (IEP). The current study investigates whether or not a similar correlation is observed with other surfactants, namely, the acidic Span 80 and the basic OLOA 11000. This is accomplished by measuring the electrophoretic mobility of a series of mineral oxides that are dispersed in Isopar-L containing various concentrations of either Span 80 or OLOA 11000. The mineral oxides used have PZC values that cover a wide range of pH, providing a systematic study of how particle and surfactant acid-base properties impact particle charge. It was found that the magnitude and polarity of particle surface charge varied linearly with the particle PZC for both surfactants used. In addition, the point at which the polarity of charge reversed for the basic surfactant OLOA 11000 was shifted to a pH of approximately 8.5, compared to the previous result of about 5 for AOT. This proves that both surfactant and particle acid-base properties are important, and provides support for the theory of acid-base charging in apolar media. PMID:23157688

  18. Cyclical budget balance measurement

    C. AUDENIS; C. PROST

    2000-01-01

    Government balances are often adjusted for changes in economic activity in order to draw a clearer picture of the underlying fiscal situation and to use this as a guide to fiscal policy analysis. International organisations estimate the cyclical component of economic activity by the current level of the output gap. Using elasticities of tax and public expenditures to GDP, they compute the cyclical part of budget balance. The structural budget balance is defined as the remainder. Our approach ...

  19. Inevitability of Balance Restoration

    Oh, Man S.

    2010-01-01

    Prolonged imbalance between input and output of any element in a living organism is incompatible with life. The duration of imbalance varies, but eventually balance is achieved. This rule applies to any quantifiable element in a compartment of finite capacity. Transient discrepancies occur regularly, but given sufficient time, balance is always achieved, because permanent imbalance is impossible, and the mechanism for eventual restoration of balance is foolproof. The kidney is a central playe...

  20. Key Roles of Lewis Acid-Base Pairs on ZnxZryOz in Direct Ethanol/Acetone to Isobutene Conversion.

    Sun, Junming; Baylon, Rebecca A L; Liu, Changjun; Mei, Donghai; Martin, Kevin J; Venkitasubramanian, Padmesh; Wang, Yong

    2016-01-20

    The effects of surface acidity on the cascade ethanol-to-isobutene conversion were studied using ZnxZryOz catalysts. The ethanol-to-isobutene reaction was found to be limited by the secondary reaction of the key intermediate, acetone, namely the acetone-to-isobutene reaction. Although the catalysts with coexisting Brønsted acidity could catalyze the rate-limiting acetone-to-isobutene reaction, the presence of Brønsted acidity is also detrimental. First, secondary isobutene isomerization is favored, producing a mixture of butene isomers. Second, undesired polymerization and coke formation prevail, leading to rapid catalyst deactivation. Most importantly, both steady-state and kinetic reaction studies as well as FTIR analysis of adsorbed acetone-d6 and D2O unambiguously showed that a highly active and selective nature of balanced Lewis acid-base pairs was masked by the coexisting Brønsted acidity in the aldolization and self-deoxygenation of acetone to isobutene. As a result, ZnxZryOz catalysts with only Lewis acid-base pairs were discovered, on which nearly a theoretical selectivity to isobutene (∼ 88.9%) was successfully achieved, which has never been reported before. Moreover, the absence of Brønsted acidity in such ZnxZryOz catalysts also eliminates the side isobutene isomerization and undesired polymerization/coke reactions, resulting in the production of high purity isobutene with significantly improved catalyst stability (catalyst for C-C coupling via aldolization reaction. PMID:26624526

  1. Identifying Balance in a Balanced Scorecard System

    Aravamudhan, Suhanya; Kamalanabhan, T. J.

    2007-01-01

    In recent years, strategic management concepts seem to be gaining greater attention from the academicians and the practitioner's alike. Balanced Scorecard (BSC) concept is one such management concepts that has spread in worldwide business and consulting communities. The BSC translates mission and vision statements into a comprehensive set of…

  2. Conclusion: The balanced company

    Scheuer, John Damm; Jensen, Inger

    2013-01-01

    This concluding chapter brings together the various research findings of the book "The balanced company - organizing for the 21st Century" and develops a general overview of their implications for our understanding of the balancing processes unfolding in companies and organizations....

  3. Spectroscopic study on variations in illite surface properties after acid-base titration

    2003-01-01

    FT-IR, Raman microscopy, XRD, 29 Si and 27 Al MAS NMR, were used to investigate changes in surface properties of a natural illitesample after acid-base potentiometric titration. The characteristic XRD lines indicated the presence of surface Al-Si complexes, preferable to Al(OH)3 precipitates. In the microscopic Raman spectra, the vibration peaks of Si-O and Al-O bonds diminished as a result of treatment withacid, then increased after hydroxide back titration. The varied ratio of signal intensity between Ⅳ Al and Ⅵ At species in 27 Al MAS NMRspectra, together with the stable BET surface area after acidimetric titration, suggested that edge faces and basal planes in the layer structure ofillite participated in dissolution of structural components. The combined spectroscopic evidence demonstrated that the reactions between illitesurfaces and acid-leaching silicic acid and aluminum ions should be considered in the model description of surface acid-base properties of theaqueous illite.

  4. Acid-Base Behavior in Hydrothermal Processing of Wastes - Final Report

    A major obstacle to development of hydrothermal oxidation technology has been a lack of scientific knowledge of chemistry in hydrothermal solution above 350 C, particularly acid-base behavior, and transport phenomena, which is needed to understand corrosion, metal-ion complexation, and salt precipitation and recovery. Our objective has been to provide this knowledge with in situ UV-visible spectroscopic measurements and fully molecular computer simulation. Our recent development of relatively stable organic UV-visible pH indicators for supercritical water oxidation offers the opportunity to characterize buffers and to monitor acid-base titrations. These results have important implications for understanding reaction pathways and yields for decomposition of wastes in supercritical water

  5. Balancing Trust and Control

    Jagd, Søren

    This paper focuses on the leadership challenge of balancing trust and control. The relation between trust and control has for a long time been a puzzling issue for management researchers. In the paper I first show that there has been a dramatic change in the way the relation between trust and...... control has been conceptualized in trust research. While the relation between trust and control earlier was conceptualized as a more or less stable balance between trust and control, more recent research conceptualizes the relation between trust and control more as a dynamical process that involves an...... ongoing process of balancing the relation between trust and control. Second, taking the departure in the recent conceptualization of the balance between trust and control as an interactive process I discuss the challenges for management in handling this more subtle balancing of trust and control. The...

  6. Mass balance myths

    In the event of an oil spill at sea, remediation technologies rely on oil spill monitoring and mass balance calculations. The types of oil spills that require knowledge of mass-balance include weathering studies, dispersant-effectiveness testing, measurement of response effectiveness and damage assessment. Non-destructive and non-interfering measuring methods are needed to find components of the mass balance equation such as temporal and spatial distribution of the oil thickness, and the temporal and spatial distribution of oil concentration in the sub-surface plume. The main challenge is the variation in the size scale of laboratory and open ocean measurements. Most large scale oil-spill experiments do not have scientific credibility because there are few situations in which all the oil in the system is accounted for. While some components are accurately accounted for, others ignore mass balance, or the range of measurements is not sufficient to allow for computation of mass balance. 48 refs

  7. Determination of low citric acid concentrations in a mixture of weak acid/bases

    Lahav, O.; Shlafman, E.; Cochva, M.

    2005-01-01

    A titration approach was developed to measure low concentrations of citric acid (C6H8O7) in a mixture of other weak acid/ bases. Two methods were tested. The first and more practical method (a 4-point titration procedure) is applicable in conditions where volatile fatty acids (VFAs) are not normally present. The second method (a 5-point titration procedure) was developed for anaerobic environments where VFAs may be encountered. Generally, fairly accurate and repetitive results (precision > 95...

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

    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. PMID:26138135

  9. Real-Time Detection of Deoxyribonucleic Acid Bases via their Negative Differential Conductance Signature

    Dragoman, Daniela; Dragoman, Mircea

    2009-01-01

    In this paper we present a method for the real-time detection of the bases of the deoxyribonucleic acid using their signatures in negative differential conductance measurements. The present methods of electronic detection of deoxyribonucleic acid bases are based on a statistical analysis because the electrical currents of the four bases are weak and do not differ significantly from one base to another. In contrast, we analyze a device that combines the accumulated knowledge in nanopore and sc...

  10. Synthesis and Properties of Lactic Acid-based Cross-linked Poly(ester-amide)

    Yue Ying HE; Cong Ming XIAO

    2006-01-01

    A novel lactic acid-based cross-linked poly(ester-amide) (LCPEA) was synthesized. The gel fraction of the LCPEA could be modulated by the reaction conditions and it affected the mechanical and thermal properties of the LCPEA. The tensile strength, elastic modulus and bend strength of the LCPEA of 65% gel fraction were 4.65, 136.55 and 39.63 MPa, respectively. The thermal decomposition temperature (50 wt%) of the LCPEA was around 410 ℃.

  11. Acid-base and electrolyte disorders in patients with diabetes mellitus

    Nikolaos Sotirakopoulos

    2012-01-01

    Full Text Available Diabetes mellitus is the most common metabolic disorder in the community. The diabetics may suffer from acid-base and electrolyte disorders due to complications of diabetes mellitus and the medication they receive. In this study, acid-base and electrolyte disorders were evaluated among outpatient diabetics in our hospital. The study consisted of patients with diabetes mellitus who visited the hospital as outpatients between the period January 1, 2004 to December 31, 2006. The patients′ medical history, age and type of diabetes were noted, including whether they were taking diuretics and calcium channel blockers or not. Serum creatinine, proteins, sodium, potassium and chloride and blood gases were measured in all patients. Proteinuria was measured by 24-h urine collection. Two hundred and ten patients were divided in three groups based on the serum creatinine. Group A consisted of 114 patients that had serum creatinine 3.1 mg/dL. Of the 210 patients, 176 had an acid-base disorder. The most common disorder noted in group A was metabolic alkalosis. In groups B and C, the common disorders were metabolic acidosis and alkalosis, and metabolic acidosis, respectively. The most common electrolyte disorders were hypernatremia (especially in groups A and B, hyponatremia (group C and hyperkalemia (especially in groups B and C. It is concluded that: (a in diabetic outpatients, acid-base and electrolyte disorders occurred often even if the renal function is normal, (b the most common disorders are metabolic alkalosis and metabolic acidosis (the frequency increases with the deterioration of the renal function and (c the common electrolyte disorders are hypernatremia and hypokalemia.

  12. Biodiesel Production from Spent Fish Frying Oil Through Acid-Base Catalyzed Transesterification

    Abdalrahman B. Fadhil; Mohammed M. Dheyab; Kareem M. Ahmed; Marwa H. Yahya

    2012-01-01

    Biodiesel fuels were prepared from a special type of frying oil namely spent fish frying oil through two step transesterification viz. acid-base catalyzed transesterification. Hydrochloric acid and potassium hydroxide with methanol were used for this purpose. The oil was pre-treated with (1.0 wt% HCl) and methanol to reduce free fatty acids content of the oil. Then, conditions of the base catalyzed step such as base concentration, reaction temperature, methanol to oil molar ratio and reaction...

  13. NaVirCept - Nucleic Acid-Based Anti-Viral Project

    Vaccines are generally considered to be the most effective countermeasures to bacterial and viral diseases, however, licensed vaccines against many disease agents are either not available or their efficacies have not been demonstrated. Vaccines are generally agent specific in terms of treatment spectrum and are subject to defeat through natural mutation or through directed efforts. With respect to viral therapeutics, one of the major limitations associated with antiviral drugs is acquired drug resistance caused by antigenic shift or drift. A number of next-generation prophylactic and/or therapeutic measures are on the horizon. Of these, nucleic acid-based drugs are showing great antiviral potential. These drugs elicit long-lasting, broad spectrum protective immune responses, especially to respiratory viral pathogens. The Nucleic Acid-Based Antiviral (NaVirCept) project provides the opportunity to demonstrate the effectiveness of novel medical countermeasures against military-significant endemic and other viral threat agents. This project expands existing DRDC drug delivery capability development, in the form of proprietary liposome intellectual property, by coupling it with leading-edge nucleic acid-based technology to deliver effective medical countermeasures that will protect deployed personnel and the warfighter against a spectrum of viral disease agents. The technology pathway will offer a means to combat emerging viral diseases or modified threat agents such as the bird flu or reconstructed Spanish flu without going down the laborious, time-consuming and expensive paths to develop countermeasures for each new and/or emerging viral disease organism.(author)

  14. Aqueous extracts of Mozambican plants as alternative and environmentally safe acid-base indicators.

    Macuvele, Domingos Lusitaneo Pier; Sithole, Gerre Zebedias Samo; Cesca, Karina; Macuvele, Suzana Lília Pinare; Matsinhe, Jonas Valente

    2016-06-01

    Indicators are substances that change color as the pH of the medium. Many of these substances are dyes of synthetic origin. The mulala plant (Euclea natalensis), which roots are commonly used by rural communities for their oral hygiene, and roseira (Hibiscus rosa-sinensis), an ornamental plant, are abundant in Mozambique. Currently, synthetic acid-base indicators are most commonly used but have environmental implications and, on the other hand, are expensive products, so the demand for natural indicators started. This study investigated the applicability of aqueous extracts of H. rosa-sinensis and E. natalensis as acid-base indicators. Ground on this work, the extracts can be used as acid-base indicators. On the basis of the absorption spectroscopy in both the UV-Vis region and previous studies, it was possible to preliminarily pinpoint anthocyanins and naphthoquinones as responsible for the shifting of colors depending on the pH range of aqueous extracts of H. rosa-sinensis and E. natalensis. These natural indicators are easily accessible, inexpensive, easy to extract, environmentally safe, and locally available. PMID:26936478

  15. Active balance system and vibration balanced machine

    Qiu, Songgang (Inventor); Augenblick, John E. (Inventor); Peterson, Allen A. (Inventor); White, Maurice A. (Inventor)

    2005-01-01

    An active balance system is provided for counterbalancing vibrations of an axially reciprocating machine. The balance system includes a support member, a flexure assembly, a counterbalance mass, and a linear motor or an actuator. The support member is configured for attachment to the machine. The flexure assembly includes at least one flat spring having connections along a central portion and an outer peripheral portion. One of the central portion and the outer peripheral portion is fixedly mounted to the support member. The counterbalance mass is fixedly carried by the flexure assembly along another of the central portion and the outer peripheral portion. The linear motor has one of a stator and a mover fixedly mounted to the support member and another of the stator and the mover fixedly mounted to the counterbalance mass. The linear motor is operative to axially reciprocate the counterbalance mass.

  16. Born energy, acid-base equilibrium, structure and interactions of end-grafted weak polyelectrolyte layers

    Nap, R. J.; Tagliazucchi, M.; Szleifer, I., E-mail: igalsz@northwestern.edu [Department of Biomedical Engineering, Department of Chemistry, and Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3100 (United States)

    2014-01-14

    This work addresses the effect of the Born self-energy contribution in the modeling of the structural and thermodynamical properties of weak polyelectrolytes confined to planar and curved surfaces. The theoretical framework is based on a theory that explicitly includes the conformations, size, shape, and charge distribution of all molecular species and considers the acid-base equilibrium of the weak polyelectrolyte. Namely, the degree of charge in the polymers is not imposed but it is a local varying property that results from the minimization of the total free energy. Inclusion of the dielectric properties of the polyelectrolyte is important as the environment of a polymer layer is very different from that in the adjacent aqueous solution. The main effect of the Born energy contribution on the molecular organization of an end-grafted weak polyacid layer is uncharging the weak acid (or basic) groups and consequently decreasing the concentration of mobile ions within the layer. The magnitude of the effect increases with polymer density and, in the case of the average degree of charge, it is qualitatively equivalent to a small shift in the equilibrium constant for the acid-base equilibrium of the weak polyelectrolyte monomers. The degree of charge is established by the competition between electrostatic interactions, the polymer conformational entropy, the excluded volume interactions, the translational entropy of the counterions and the acid-base chemical equilibrium. Consideration of the Born energy introduces an additional energetic penalty to the presence of charged groups in the polyelectrolyte layer, whose effect is mitigated by down-regulating the amount of charge, i.e., by shifting the local-acid base equilibrium towards its uncharged state. Shifting of the local acid-base equilibrium and its effect on the properties of the polyelectrolyte layer, without considering the Born energy, have been theoretically predicted previously. Account of the Born energy leads

  17. Born energy, acid-base equilibrium, structure and interactions of end-grafted weak polyelectrolyte layers

    Nap, R. J.; Tagliazucchi, M.; Szleifer, I.

    2014-01-01

    This work addresses the effect of the Born self-energy contribution in the modeling of the structural and thermodynamical properties of weak polyelectrolytes confined to planar and curved surfaces. The theoretical framework is based on a theory that explicitly includes the conformations, size, shape, and charge distribution of all molecular species and considers the acid-base equilibrium of the weak polyelectrolyte. Namely, the degree of charge in the polymers is not imposed but it is a local varying property that results from the minimization of the total free energy. Inclusion of the dielectric properties of the polyelectrolyte is important as the environment of a polymer layer is very different from that in the adjacent aqueous solution. The main effect of the Born energy contribution on the molecular organization of an end-grafted weak polyacid layer is uncharging the weak acid (or basic) groups and consequently decreasing the concentration of mobile ions within the layer. The magnitude of the effect increases with polymer density and, in the case of the average degree of charge, it is qualitatively equivalent to a small shift in the equilibrium constant for the acid-base equilibrium of the weak polyelectrolyte monomers. The degree of charge is established by the competition between electrostatic interactions, the polymer conformational entropy, the excluded volume interactions, the translational entropy of the counterions and the acid-base chemical equilibrium. Consideration of the Born energy introduces an additional energetic penalty to the presence of charged groups in the polyelectrolyte layer, whose effect is mitigated by down-regulating the amount of charge, i.e., by shifting the local-acid base equilibrium towards its uncharged state. Shifting of the local acid-base equilibrium and its effect on the properties of the polyelectrolyte layer, without considering the Born energy, have been theoretically predicted previously. Account of the Born energy leads

  18. Load Balancing Scientific Applications

    Pearce, Olga Tkachyshyn [Texas A & M Univ., College Station, TX (United States)

    2014-12-01

    The largest supercomputers have millions of independent processors, and concurrency levels are rapidly increasing. For ideal efficiency, developers of the simulations that run on these machines must ensure that computational work is evenly balanced among processors. Assigning work evenly is challenging because many large modern parallel codes simulate behavior of physical systems that evolve over time, and their workloads change over time. Furthermore, the cost of imbalanced load increases with scale because most large-scale scientific simulations today use a Single Program Multiple Data (SPMD) parallel programming model, and an increasing number of processors will wait for the slowest one at the synchronization points. To address load imbalance, many large-scale parallel applications use dynamic load balance algorithms to redistribute work evenly. The research objective of this dissertation is to develop methods to decide when and how to load balance the application, and to balance it effectively and affordably. We measure and evaluate the computational load of the application, and develop strategies to decide when and how to correct the imbalance. Depending on the simulation, a fast, local load balance algorithm may be suitable, or a more sophisticated and expensive algorithm may be required. We developed a model for comparison of load balance algorithms for a specific state of the simulation that enables the selection of a balancing algorithm that will minimize overall runtime.

  19. Energy balance measurement

    Dhurandhar, N V; Schoeller, D; Brown, A W;

    2015-01-01

    Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self......-reports of EI and PAEE are imperfect, but nevertheless deserving of use, to a view commensurate with the evidence that self-reports of EI and PAEE are so poor that they are wholly unacceptable for scientific research on EI and PAEE. While new strategies for objectively determining energy balance are in their...... of energy balance....

  20. Keeping Your Balance

    ... or problems with balance. Sometimes your doctor or physical therapist can reposition the crystals in your ear and ... Adherence Calcium/Vitamin D Nutrition Overall Health Fractures/Fall Prevention Exercise/Safe Movement Safe Movement & Exercise Videos ...

  1. National Energy Balance - 1984

    The National Energy Balance - 1984 shows energy fluxes of several primary and secondary energy sources, since the productions to final consumption in the main economic sectors, since 1973 to 1983. (E.G.)

  2. National Energy Balance - 1985

    The National Energy Balance - 1985 shows energy fluxes of several primary and secondary energy sources, since the production to the final consumption in the main economic sectors, since 1974 to 1984 (E.G.)

  3. National Energy Balance-1987

    The National Energy Balance - 1987 showns energy fluxes of several primary and secondary energy sources, since the production to final consumption in the main economic sectors, since 1971 to 1986. (E.G.)

  4. Detailed balance and entanglement

    We study a connection between quantum detailed balance, which is a concept of importance in statistical mechanics, and entanglement. We also explore how this connection fits into thermofield dynamics. (paper)

  5. Balance Disorders (For Parents)

    ... usually used on infants and young children. electronystagmogram (ENG). To assess balance, electrodes are placed around the ... videonystagmography (VNG). This test is similar to an ENG, only the child has to focus on the ...

  6. Balance costs for windpower

    Skaflestad, Stig

    2009-01-01

    Wind power scheduling is subject to high forecast uncertainty compared to the dominant Norwegian energy source, hydro power. The regulating market, also known as the balance market, is a market solution for optimal operation of the Nordic power system, putting a price on schedule deviations. Schedules, or production/consumption plans, are collected daily, 12 hours prior to delivery by the system operator Statnett. Wind power is especially vulnerable to balance costs due to the relatively high...

  7. Selectively Balancing Unit Vectors

    Blokhuis, Aart; Chen, Hao

    2016-01-01

    A set $U$ of unit vectors is selectively balancing if one can find two disjoint subsets $U^+$ and $U^-$, not both empty, such that the Euclidean distance between the sum of $U^+$ and the sum of $U^-$ is smaller than $1$. We prove that, to guarantee a selectively balancing set, $n \\log n$ unit vectors suffice for sufficiently large $n$, but $\\tfrac{1}{23} n \\log n$ unit vectors won't be enough for infinitely many $n$.

  8. Greenland Ice Sheet Mass Balance

    Reeh, N.

    1984-01-01

    Mass balance equation for glaciers; areal distribution and ice volumes; estimates of actual mass balance; loss by calving of icebergs; hydrological budget for Greenland; and temporal variations of Greenland mass balance are examined.

  9. Balances instruments, manufacturers, history

    Robens, Erich; Kiefer, Susanne

    2014-01-01

    The book deals mainly with direct mass determination by means of a conventional balances. It covers the history of the balance from the beginnings in Egypt earlier than 3000 BC to recent developments. All balance types are described with emphasis on scientific balances. Methods of indirect mass determination, which are applied to very light objects like molecules and the basic particles of matter and celestial bodies, are included.  As additional guidance, today’s manufacturers are listed and the profile of important companies is reviewed. Several hundred photographs, reproductions and drawings show instruments and their uses. This book includes commercial weighing instruments for merchandise and raw materials in workshops as well as symbolic weighing in the ancient Egyptian’s ceremony of ‘Weighing of the Heart’, the Greek fate balance, the Roman  Justitia, Juno Moneta and Middle Ages scenes of the Last Judgement with Jesus or St. Michael and of modern balances. The photographs are selected from the...

  10. Watt and joule balances

    Robinson, Ian A.

    2014-04-01

    The time is fast approaching when the SI unit of mass will cease to be based on a single material artefact and will instead be based upon the defined value of a fundamental constant—the Planck constant—h . This change requires that techniques exist both to determine the appropriate value to be assigned to the constant, and to measure mass in terms of the redefined unit. It is important to ensure that these techniques are accurate and reliable to allow full advantage to be taken of the stability and universality provided by the new definition and to guarantee the continuity of the world's mass measurements, which can affect the measurement of many other quantities such as energy and force. Up to now, efforts to provide the basis for such a redefinition of the kilogram were mainly concerned with resolving the discrepancies between individual implementations of the two principal techniques: the x-ray crystal density (XRCD) method [1] and the watt and joule balance methods which are the subject of this special issue. The first three papers report results from the NRC and NIST watt balance groups and the NIM joule balance group. The result from the NRC (formerly the NPL Mk II) watt balance is the first to be reported with a relative standard uncertainty below 2 × 10-8 and the NIST result has a relative standard uncertainty below 5 × 10-8. Both results are shown in figure 1 along with some previous results; the result from the NIM group is not shown on the plot but has a relative uncertainty of 8.9 × 10-6 and is consistent with all the results shown. The Consultative Committee for Mass and Related Quantities (CCM) in its meeting in 2013 produced a resolution [2] which set out the requirements for the number, type and quality of results intended to support the redefinition of the kilogram and required that there should be agreement between them. These results from NRC, NIST and the IAC may be considered to meet these requirements and are likely to be widely debated

  11. Synthesis, characterization and catalytic activity of acid-base bifunctional materials through protection of amino groups

    Shao, Yanqiu [College of Chemistry, Jilin University, Changchun 130023 (China); College of Chemistry, Mudanjiang Normal University, Mudanjiang 157012 (China); Liu, Heng; Yu, Xiaofang [College of Chemistry, Jilin University, Changchun 130023 (China); Guan, Jingqi, E-mail: guanjq@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130023 (China); Kan, Qiubin, E-mail: qkan@mail.jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130023 (China)

    2012-03-15

    Graphical abstract: Acid-base bifunctional mesoporous material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized under low acidic medium through protection of amino groups. Highlights: Black-Right-Pointing-Pointer The acid-base bifunctional material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized through protection of amino groups. Black-Right-Pointing-Pointer The obtained bifunctional material was tested for aldol condensation. Black-Right-Pointing-Pointer The SO{sub 3}H-SBA-15-NH{sub 2} catalyst containing amine and sulfonic acid groups exhibited excellent acid-basic properties. -- Abstract: Acid-base bifunctional mesoporous material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized under low acidic medium through protection of amino groups. X-ray diffraction (XRD), N{sub 2} adsorption-desorption, transmission electron micrographs (TEM), back titration, {sup 13}C magic-angle spinning (MAS) NMR and {sup 29}Si magic-angle spinning (MAS) NMR were employed to characterize the synthesized materials. The obtained bifunctional material was tested for aldol condensation reaction between acetone and 4-nitrobenzaldehyde. Compared with monofunctional catalysts of SO{sub 3}H-SBA-15 and SBA-15-NH{sub 2}, the bifunctional sample of SO{sub 3}H-SBA-15-NH{sub 2} containing amine and sulfonic acid groups exhibited excellent acid-basic properties, which make it possess high activity for the aldol condensation.

  12. Synthesis of acid-base bifunctional mesoporous materials by oxidation and thermolysis

    Yu, Xiaofang [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Zou, Yongcun [State Key Laboratory of Inoranic Synthesis and Preparative Chemistryg, College of Chemistry, Jilin University, Changchun 130012 (China); Wu, Shujie; Liu, Heng [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Guan, Jingqi, E-mail: guanjq@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Kan, Qiubin, E-mail: qkan@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China)

    2011-06-15

    Graphical abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst. The obtained sample of SO{sub 3}H-MCM-41-NH{sub 2} containing amine and sulfonic acids exhibits excellent catalytic activity in aldol condensation reaction. Research highlights: {yields} Synthesize acid-base bifunctional mesoporous materials SO{sub 3}H-MCM-41-NH{sub 2}. {yields} Oxidation and then thermolysis to generate acidic site and basic site. {yields} Exhibit good catalytic performance in aldol condensation reaction between acetone and various aldehydes. -- Abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst SO{sub 3}H-MCM-41-NH{sub 2}. This method was achieved by co-condensation of tetraethylorthosilicate (TEOS), 3-mercaptopropyltrimethoxysilane (MPTMS) and (3-triethoxysilylpropyl) carbamicacid-1-methylcyclohexylester (3TAME) in the presence of cetyltrimethylammonium bromide (CTAB), followed by oxidation and then thermolysis to generate acidic site and basic site. X-ray diffraction (XRD) and transmission electron micrographs (TEM) show that the resultant materials keep mesoporous structure. Thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), back titration, solid-state {sup 13}C CP/MAS NMR and solid-state {sup 29}Si MAS NMR confirm that the organosiloxanes were condensed as a part of the silica framework. The bifunctional sample (SO{sub 3}H-MCM-41-NH{sub 2}) containing amine and sulfonic acids exhibits excellent acid-basic properties, which make it possess high activity in aldol condensation reaction between acetone and various aldehydes.

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

    Riffet, Vanessa; Frison, Gilles; Bouchoux, Guy

    2011-01-01

    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, protona...

  14. The role of gelatin in a methacrylic acid based gel dosimeter

    In this work, the dose response of a methacrylic acid based gel dosimeter containing different concentrations of gelatin is examined to clarify the role of gelatin in the polymerization process. Direct temperature monitoring of the gel throughout the irradiation process is adopted as the method. In addition, to investigate the function of gelatin on polymerization, another experiments are performed after replacing gelatin with some acids. From the results, it is concluded that gelatin is an indispensable component in the polymerization reaction which acts as a 'trigger', and that the peptide structure in gelatin also assumes an important role.

  15. Determination of the acidic sites of purified single-walled carbon nanotubes by acid base titration

    Hu, H.; Bhowmik, P.; Zhao, B.; Hamon, M. A.; Itkis, M. E.; Haddon, R. C.

    2001-09-01

    We report the measurement of the acidic sites in three different samples of commercially available full-length purified single-walled carbon nanotubes (SWNTs) - as obtained from CarboLex (CLI), Carbon Solutions (CSI) and Tubes@Rice (TAR) - by simple acid-base titration methods. Titration of the purified SWNTs with NaOH and NaHCO 3 solutions was used to determine the total percentage of acidic sites and carboxylic acid groups, respectively. The total percentage of acidic sites in full length purified SWNTs from TAR, CLI and CSI are about 1-3%.

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

    Masevicius, Fabio D; Dubin, Arnaldo

    2015-01-01

    The Stewart approach-the application of basic physical-chemical principles of aqueous solutions to blood-is an appealing method for analyzing acid-base disorders. These principles mainly dictate that pH is determined by three independent variables, which change primarily and independently of one other. In blood plasma in vivo these variables are: (1) the PCO2; (2) the strong ion difference (SID)-the difference between the sums of all the strong (i.e., fully dissociated, chemically nonreacting...

  17. Acid-base properties of the surface of InSb-CdTe solid solutions

    Acid-base properties of the surface of solid solutions and binary components of the InSb-CdTe system are studied using IR spectroscopy, conductometric titration, and measuring the pH-isoelectric state upon treating the test samples by evacuation under atmospheric conditions, exposure to gases (NO2, NH3) and γ radiation. The nature, strength, and concentration of acid centers are determined. Variation in the concentration of acid centers is evaluated as a function of the above factors and changes in the composition of the system

  18. Relationship of students' conceptual representations and problem-solving abilities in acid-base chemistry

    Powers, Angela R.

    2000-10-01

    This study explored the relationship between secondary chemistry students' conceptual representations of acid-base chemistry, as shown in student-constructed concept maps, and their ability to solve acid-base problems, represented by their score on an 18-item paper and pencil test, the Acid-Base Concept Assessment (ABCA). The ABCA, consisting of both multiple-choice and short-answer items, was originally designed using a question-type by subtopic matrix, validated by a panel of experts, and refined through pilot studies and factor analysis to create the final instrument. The concept map task included a short introduction to concept mapping, a prototype concept map, a practice concept-mapping activity, and the instructions for the acid-base concept map task. The instruments were administered to chemistry students at two high schools; 108 subjects completed both instruments for this study. Factor analysis of ABCA results indicated that the test was unifactorial for these students, despite the intention to create an instrument with multiple "question-type" scales. Concept maps were scored both holistically and by counting valid concepts. The two approaches were highly correlated (r = 0.75). The correlation between ABCA score and concept-map score was 0.29 for holistically-scored concept maps and 0.33 for counted-concept maps. Although both correlations were significant, they accounted for only 8.8 and 10.2% of variance in ABCA scores, respectively. However, when the reliability of the instruments used is considered, more than 20% of the variance in ABCA scores may be explained by concept map scores. MANOVAs for ABCA and concept map scores by instructor, student gender, and year in school showed significant differences for both holistic and counted concept-map scores. Discriminant analysis revealed that the source of these differences was the instruction variable. Significant differences between classes receiving different instruction were found in the frequency of

  19. Quantum chemistry contribution to the understanding of the acid-base phenomena

    The various physical and chemical phenomena involved at the atomic and molecular level of a two material interface, are studied. When intimately in contact, intermolecular range forces are established between their atoms. These forces are divided in two categories: short range and long range forces, and according to the intervention rate, the bonding will be more or less strong. A quantitative approach, in terms of quantum chemistry of the so called acid-base interactions, is proposed and prospects for this approach with the view of enhancing or diminishing the bonding strength between two materials, are discussed

  20. Balanced Integrated Regulatory Oversight

    Reactor safety, protecting the public health and safety, and protecting the environment must always be the nuclear regulator's top priorities. Enabling the use of nuclear power for the benefit of society, while protecting the public and the environment requires the regulator to balance many factors. In addition, the regulator is only one part of the overall government that must consider many factors as it carries out its societal responsibilities. Some of the factors that must be balanced and the practical impacts on how the regulator carries out its responsibilities will be addressed. The first International Conference on Effective Regulatory Systems, held in Moscow, Russian Federation, in 2006, focused on safety and security challenges with a goal of improving regulatory effectiveness through cooperation and sharing of information and best practices. The challenge of meeting both safety and security objectives is one example of potentially competing programmes that must be balanced. Other balances that must be evaluated include the benefits of safety improvements compared to the cost of implementation, the use of deterministic and probabilistic approaches, communication openness balanced with the protection of information that could be used for detrimental purposes, and timeliness of regulatory decision making balanced with the need to perform quality work in support of oversight responsibilities. A balanced and integrated approach to regulatory oversight is vital to ensuring that the regulatory body remains effective in its mission to enable the use of nuclear power while protecting the public and the environment. This concept is applicable to nations beginning a nuclear programme as well as established and experienced regulatory bodies. (author)

  1. Progress in Research on the Relationship Between Acute cardiovascular disease and Acid-Base Imbalance%酸碱失衡与急性心血管疾病关系研究进展

    孙广昊(综述); 宋杰(审校)

    2014-01-01

    As common diseases of internal medicine,cardiovascular disease progress rapidly with complicated pathological changes, and often cause acid-base balance disturbance in the body, particularly in patients with acute myocardial infarction disease. Many clinical studies have shown that acid-base imbalance in the body can cause acute cardiovascular system damage, affecting the prognosis of the disease,and even leads to cardiogenic shock, therefore,monitoring of the acid-base indicators for diagnosis,treatment.and prognosis of acute cardiovascular disease plays an important role in clinical.%急性心血管疾病作为内科常见疾病,病情进展快,病理变化复杂,常出现体内酸碱平衡紊乱,酸碱失衡尤其见于急性心肌梗死疾病中。临床研究表明,体内酸碱失衡可能会导致急性心血管系统损伤,影响疾病的预后,甚至导致心源性休克发生,因此各项酸碱监测指标对于急性心血管疾病的诊断、治疗监测和预后有着重要临床作用。

  2. The acid-base and catalytic properties of the surface of ZnSe-CdSe solid solutions

    Acid-base properties of the surface of slid solutions ZnxCd1-xSe and initial binary semiconductor compounds (ZnSe, CdSe) were studied by the method of probe molecules on acid and base centers. Nature of the acid-base centers was ascertained, their strength and quantitative content on the system samples of different composition were evaluated. Acid-base properties were compared with catalytic ones in reference to propanol-2 decomposition. Similarity and difference in acid-base and catalytic properties of the surface of binary semiconductors and solid solutions were pointed out. Specific features of the solid solutions were detected, which are largely pronounced in the course of ascertaining the property-composition dependence

  3. Automatic force balance calibration system

    Ferris, Alice T.

    1995-05-01

    A system for automatically calibrating force balances is provided. The invention uses a reference balance aligned with the balance being calibrated to provide superior accuracy while minimizing the time required to complete the calibration. The reference balance and the test balance are rigidly attached together with closely aligned moment centers. Loads placed on the system equally effect each balance, and the differences in the readings of the two balances can be used to generate the calibration matrix for the test balance. Since the accuracy of the test calibration is determined by the accuracy of the reference balance and current technology allows for reference balances to be calibrated to within +/-0.05% the entire system has an accuracy of +/-0.2%. The entire apparatus is relatively small and can be mounted on a movable base for easy transport between test locations. The system can also accept a wide variety of reference balances, thus allowing calibration under diverse load and size requirements.

  4. Investigations of (acid+base) equilibria in systems modelling interactions occurring in biomolecules

    By using the potentiometric microtitration method, acidity constants, Ka, anionic, KAHA-, and cationic, KBHB+, homoconjugation constants, as well as molecular heteroconjugation, KBHA, constants have been determined in (acid+base) systems formed by the following compounds: acetic acid, phenol, n-butylamine, imidazole, and 4(5)-methylimidazole. These compounds constitute fragments of the side chains of amino acids capable of proton exchange in active sites of enzymes. The (acid+base) equilibria were studied in five polar solvents of different properties, namely in aprotic protophobic acetonitrile, acetone and propylene carbonate, in aprotic protophilic dimethyl sulfoxide and in amphiprotic methanol. The lowest values of the acidity constants of the molecular and cationic acids have been found in aprotic protophobic polar solvents - acetonitrile, propylene carbonate and acetone. Their acid strength have been found to depend on solvent basicity expressed as donor numbers, DN. These media, in particular acetonitrile and acetone, are also favourable for establishing molecular homo- and heteroconjugation equilibria. The most stable homocomplexes are formed in the case of acetic acid (KAHA- values range from 2.26 to 3.56 in these media, being more than an order of magnitude higher than those for the remaining compounds). The magnitudes of lgKBHA reveal that the most stable heterocomplexes are formed by n-butylamine and acetic acid that are characterized by the smallest differences in pKa values

  5. Surface functionalization of two-dimensional metal chalcogenides by Lewis acid-base chemistry.

    Lei, Sidong; Wang, Xifan; Li, Bo; Kang, Jiahao; He, Yongmin; George, Antony; Ge, Liehui; Gong, Yongji; Dong, Pei; Jin, Zehua; Brunetto, Gustavo; Chen, Weibing; Lin, Zuan-Tao; Baines, Robert; Galvão, Douglas S; Lou, Jun; Barrera, Enrique; Banerjee, Kaustav; Vajtai, Robert; Ajayan, Pulickel

    2016-05-01

    Precise control of the electronic surface states of two-dimensional (2D) materials could improve their versatility and widen their applicability in electronics and sensing. To this end, chemical surface functionalization has been used to adjust the electronic properties of 2D materials. So far, however, chemical functionalization has relied on lattice defects and physisorption methods that inevitably modify the topological characteristics of the atomic layers. Here we make use of the lone pair electrons found in most of 2D metal chalcogenides and report a functionalization method via a Lewis acid-base reaction that does not alter the host structure. Atomic layers of n-type InSe react with Ti(4+) to form planar p-type [Ti(4+)n(InSe)] coordination complexes. Using this strategy, we fabricate planar p-n junctions on 2D InSe with improved rectification and photovoltaic properties, without requiring heterostructure growth procedures or device fabrication processes. We also show that this functionalization approach works with other Lewis acids (such as B(3+), Al(3+) and Sn(4+)) and can be applied to other 2D materials (for example MoS2, MoSe2). Finally, we show that it is possible to use Lewis acid-base chemistry as a bridge to connect molecules to 2D atomic layers and fabricate a proof-of-principle dye-sensitized photosensing device. PMID:26828848

  6. Site-specific acid-base properties of pholcodine and related compounds.

    Kovács, Z; Hosztafi, S; Noszál, B

    2006-11-01

    The acid-base properties of pholcodine, a cough-depressant agent, and related compounds including metabolites were studied by 1H NMR-pH titrations, and are characterised in terms of macroscopic and microscopic protonation constants. New N-methylated derivatives were also synthesized in order to quantitate site- and nucleus-specific protonation shifts and to unravel microscopic acid-base equilibria. The piperidine nitrogen was found to be 38 and 400 times more basic than its morpholine counterpart in pholcodine and norpholcodine, respectively. The protonation data show that the molecule of pholcodine bears an average of positive charge of 1.07 at physiological pH, preventing it from entering the central nervous system, a plausible reason for its lack of analgesic or addictive properties. The protonation constants of pholcodine and its derivatives are interpreted by comparing with related molecules of pharmaceutical interest. The pH-dependent relative concentrations of the variously protonated forms of pholcodine and morphine are depicted in distribution diagrams. PMID:17004059

  7. Manipulation of partially oriented hydroxyapatite building blocks to form flowerlike bundles without acid-base regulation.

    Wen, Zhenliang; Wang, Zihao; Chen, Jingdi; Zhong, Shengnan; Hu, Yimin; Wang, Jianhua; Zhang, Qiqing

    2016-06-01

    The application of hydroxyapatite (HAP) in different fields depends greatly on its morphology, composition and structure. Besides, the main inorganic building blocks of human bones and teeth are also HAP. Therefore, accurate shape and aggregation control and of hydroxyapatite particles will be of great interest. Herein, oriented bundles of flowerlike HAP nanorods were successfully prepared through hydrothermal treatment without acid-base regulation, with the mono-alkyl phosphate (MAP) and sodium citrate as surfactant and chelating agent, respectively. The prepared samples were characterized by the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and zeta potential, the pH value and conductivity value of suspension were characterized by pH meter and conductivity measurement. The results showed that the MAP and citrate play an important role in assembly of HAP nanorods without acid-base regulation. Citrate calcium complex could decompose slowly and release citrate ions at hydrothermal conditions. Besides, the further decomposition of citrate ions could release aconitic acid as the reaction time prolongs. Moreover, the possible scheme for the formation process was discussed in detail. PMID:26930036

  8. The generalized Lewis acid-base titration of palladium and niobium

    The high thermodynamic stability of alloys composed of platinum group metals and group IVB and VB metals has been explained by an electronic interaction analogous to the Lewis acid-base concept for nontransition elements. The analogy is further demonstrated by the titration of palladium by addition of niobium. The activity of niobium in solid palladium was measured as a function of concentration by solid-state galvanic cells and study of the ternary oxide phase diagram. The galvanic cells were of the Pt/NbO2, Nb2O4.8/YDT/NbOy, Nb(Pd)/Pt where the solid electrolyte is yttria-doped thoria (YDT). Ternary phase diagrams for the Pd-Nb-O and Rh-Nb-O systems were obtained by characterizing samples equilibrated at 10000C. The phase relationships found in the ternary diagrams were also used to derive thermochemical data for the alloys. Thermochemical quantities for other acid-base stabilized alloys such as Nb-Rh, Ti-Pd, and Ti-Rh were also measured

  9. Activities of Heterogeneous Acid-Base Catalysts for Fragrances Synthesis: A Review

    Hartati Hartati

    2013-06-01

    Full Text Available This paper reviews various types of heterogeneous acid-base catalysts for fragrances preparation. Catalytic activities of various types of heterogeneous acid and base catalysts in fragrances preparation, i.e. non-zeolitic, zeolitic, and mesoporous molecular sieves have been reported. Generally, heterogeneous acid catalysts are commonly used in fragrance synthesis as compared to heterogeneous base catalysts. Heteropoly acids and hydrotalcites type catalysts are widely used as heterogeneous acid and base catalysts, respectively. © 2013 BCREC UNDIP. All rights reservedReceived: 20th January 2013; Revised: 31st March 2013; Accepted: 1st April 2013[How to Cite: Hartati, H., Santoso, M., Triwahyono, S., Prasetyoko, D. (2013. Activities of Heterogeneous Acid-Base Catalysts for Fragrances Synthesis: A Review. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 14-33. (doi:10.9767/bcrec.8.1.4394.14-33][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4394.14-33] | View in  |

  10. A Prebiotic Chemistry Experiment on the Adsorption of Nucleic Acids Bases onto a Natural Zeolite

    Anizelli, Pedro R.; Baú, João Paulo T.; Gomes, Frederico P.; da Costa, Antonio Carlos S.; Carneiro, Cristine E. A.; Zaia, Cássia Thaïs B. V.; Zaia, Dimas A. M.

    2015-09-01

    There are currently few mechanisms that can explain how nucleic acid bases were synthesized, concentrated from dilute solutions, and/or protected against degradation by UV radiation or hydrolysis on the prebiotic Earth. A natural zeolite exhibited the potential to adsorb adenine, cytosine, thymine, and uracil over a range of pH, with greater adsorption of adenine and cytosine at acidic pH. Adsorption of all nucleic acid bases was decreased in artificial seawater compared to water, likely due to cation complexation. Furthermore, adsorption of adenine appeared to protect natural zeolite from thermal degradation. The C=O groups from thymine, cytosine and uracil appeared to assist the dissolution of the mineral while the NH2 group from adenine had no effect. As shown by FT-IR spectroscopy, adenine interacted with a natural zeolite through the NH2 group, and cytosine through the C=O group. A pseudo-second-order model best described the kinetics of adenine adsorption, which occurred faster in artificial seawaters.

  11. A study on the role of gelatin in methacrylic-acid-based gel dosimeters

    In radiotherapy treatment, polymer gel dosimetry can be used for verifying three-dimensional (3D) dose distributions. Gelatin is generally used as a gelling agent in the dosimeters. In this paper, another role of gelatin in a methacrylic-acid-based gel dosimeter (MAGAT) is investigated. Temperature increases due to exothermic polymerization in the irradiated gel are measured directly. Dose-R2 responses are also obtained using MRI. It is shown that no appreciable increases in either temperature or R2 are observed in MAGAT dosimeters made without gelatin, and that significant temperature and R2 increases are observed when very low gelatin concentrations are used. These results indicate that gelatin is an important enabler for radiation-induced free-radical polymerization in methacrylic-acid-based gels. When gelatin is replaced by amino acids, changes in temperature are observed, along with small changes in R2. The resulting dosimeter solutions remain transparent because the polymer does not precipitate as it does in regular MAGAT dosimeters containing gelatin. When the amino acids are replaced by acids without amino groups, no temperature or R2 changes are observed, indicating that no polymer forms. These results show that amino groups (and possibly other functional groups) on the gelatin catalyze the radiation-induced free-radical polymerization that occurs in MAGAT dosimeters.

  12. Fractionating vacuum thermal deposition of polyaniline films. Effect of post-deposition acid-base treatment

    Nekrasov, A.A. (Frumkin Institute of Electrochemistry, Russian Academy of Sciences, Leninskii Prospect 31, Moscow 117071 (Russian Federation)); Ivanov, V.F. (Frumkin Institute of Electrochemistry, Russian Academy of Sciences, Leninskii Prospect 31, Moscow 117071 (Russian Federation)); Gribkova, O.L. (Frumkin Institute of Electrochemistry, Russian Academy of Sciences, Leninskii Prospect 31, Moscow 117071 (Russian Federation)); Vannikov, A.V. (Frumkin Institute of Electrochemistry, Russian Academy of Sciences, Leninskii Prospect 31, Moscow 117071 (Russian Federation))

    1994-07-15

    Vacuum thermal evaporation of a single portion of chemically synthesized polyaniline (PAN) base powder was performed step-by-step within four temperature intervals in the 240-450 C range. The vapour was deposited on quartz and SnO[sub 2]-glass substrates, each fraction being deposited on a separate substrate. The samples obtained were subjected to cyclic contrast acid-base treatment, and UV-Vis spectra of the fractions after each treatment cycle were registered. The spectra of the as-deposited fractions appear to have little in common with conventional PAN spectra. The appearance of absorption bands essential for conventional PAN spectra is found to occur for some of the fractions only after the above treatment. This is apparently due to recombination of PAN oligomer radical fragments, formed in the course of the evaporation, resulting in restoration of PAN macromolecule structure. The recombination may be intensified by conformational changes during the acid-base treatment. Cyclic voltammetry curves for the most PAN-like fractions resemble the ones for conventional PAN. ((orig.))

  13. [The favorable effect of humic acid based complex micro-element preparations in cadmium exposure].

    Hudák, A; Náray, M; Nagy, I; Molnár, M; Gömöry, I; Ungváry, G

    1997-06-01

    The authors have studied the effect of consumption of a humic acid based complex microelement preparation (potassium, magnesium, iron, zinc, manganese, copper, vanadium, cobalt, molibden, selenium bound to humic acids) for six weeks (10 ml daily) on the biological exposure indices (blood and urine cadmium levels) and clinical laboratory parameters (liver and kidney tests, blood picture) of men (n = 18; 39.7 +/- 10.4 years of age;) working in cadmium exposure for 8.3 +/- 5.0 years. The initial mean blood and urine cadmium levels of the non-smoking subjects was twice higher than that of the non-smoking male controls living in the same urban area (n = 35), and significantly correlated with the length of exposure. Their mean serum alanin-aminotransferase, gamma-glutamyl-transferase, creatinine, uric acid and urinary N-acetyl-beta-D-glucosaminidase levels were significantly higher than that of the controls. After the six-week treatment blood cadmium level, activity of serum alanin-aminotransferase, serum uric acid and urinary protein concentrations decreased significantly, the abnormal serum iron levels normalized. According to this results, the absorption of cadmium decreased on the effect of the complex microelement supplementation and the adverse laboratory changes attributable partly to cadmium exposure improved. Therefore humic acid based complex microelement supplementation is recommended as an effective tool for prevention and health protection in occupational cadmium exposure as well as for smokers known to be considerably burdened by cadmium. PMID:9254361

  14. CHARGE DEVELOPMENT AND ACID-BASE CHARACTERISTICS OF SOIL AND COMPOST HUMIC ACIDS

    P. A. CAMPITELLI

    2003-09-01

    Full Text Available In previous works, the acid-base properties, charging behavior and chemical heterogeneity of humic substances have been studied using different mathematical equations to fit the experimental data. The objective of this research is to study the charge behavior, acid-base properties and analyze the chemical heterogeneity of humic acids (HA extracted from soil and composted municipal solid waste by potentiometric titrations. The humic acids extracted from compost have some characteristics and behavior similar to those obtained from soil. The negative charge development of HA extracted from composted material are lower than those extracted from soil and increase as ionic strength increase. The amount of carboxylic groups is lower in compost HA than in soil HA The heterogeneity of HA extracted from compost is higher than those extracted from soil. As the time of composting period increase the humification processes that take place trends to produce compost HA that has similar characteristics to soil HA. We suggest that HA extracted from composted material are macromolecules "like soil humic acids", i.e. "humiclike fraction"

  15. Acid-based hydrolysis processes for ethanol from lignocellulosic materials: A review

    Keikhosro Karimi

    2007-01-01

    Full Text Available Bioethanol is nowadays one of the main actors in the fuel market. It is currently produced from sugars and starchy materials, but lignocelluloses can be expected to be major feedstocks for ethanol production in the future. Two processes are being developed in parallel for conversion of lignocelluloses to ethanol, “acid-based” and “enzyme-based” processes. The current article is dedicated to review of progress in the “acid-based-hydrolysis” process. This process was used industrially in the 1940s, during wartime, but was not economically competitive afterward. However, intensive research and development on its technology during the last three decades, in addition to the expanding ethanol market, may revive the process in large scale once again. In this paper the ethanol market, the composition of lignocellulosic materials, concentrated- and dilute-acid pretreatment and hydrolysis, plug-flow, percolation, counter-current and shrinking-bed hydrolysis reactors, fermentation of hexoses and pentoses, effects of fermentation inhibitors, downstream processing, wastewater treatment, analytical methods used, and the current commercial status of the acid-based ethanol processes are reviewed.

  16. Novel sulfonated poly (ether ether keton)/polyetherimide acid-base blend membranes for vanadium redox flow battery applications

    Highlights: • SPEEK/PEI acid-base blend membranes are prepared for VRB applications. • The acid-base blend membranes have much lower vanadium ion permeability. • The energy efficiency of SPEEK/PEI maintain around 86.9% after 50 cycles. - Abstract: Novel acid-base blend membranes composed of sulfonated poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared for vanadium redox flow battery (VRB). The blend membranes were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electronic microscopy (SEM). The ion exchange capacity (IEC), proton conductivity, water uptake, vanadium ion permeability and mechanical properties were measured. As a result, the acid-base blend membranes exhibit higher water uptake, IEC and lower vanadium ion permeability compared to Nafion117 membranes and all these properties decrease with the increase of PEI. In VRB single cell test, the VRB with blend membranes shows lower charge capacity loss, higher coulombic efficiency (CE) and energy efficiency (EE) than Nafion117 membrane. Furthermore, the acid-base blend membranes present stable performance up to 50 cycles with no significant decline in CE and EE. All experimental results indicate that the SPEEK/PEI (S/P) acid-base blend membranes show promising prospects for VRB

  17. The cryogenic balance design and balance calibration methods

    Ewald, B.; Polanski, L.; Graewe, E.

    1992-07-01

    The current status of a program aimed at the development of a cryogenic balance for the European Transonic Wind Tunnel is reviewed. In particular, attention is given to the cryogenic balance design philosophy, mechanical balance design, reliability and accuracy, cryogenic balance calibration concept, and the concept of an automatic calibration machine. It is shown that the use of the automatic calibration machine will improve the accuracy of calibration while reducing the man power and time required for balance calibration.

  18. Effect of dietary cation-anion difference on ruminal metabolism, total apparent digestibility, blood and renal acid-base regulation in lactating dairy cows.

    Martins, C M M R; Arcari, M A; Welter, K C; Gonçalves, J L; Santos, M V

    2016-01-01

    The present study aimed to evaluate the effect of dietary cation-anion difference (DCAD) on ruminal fermentation, total apparent digestibility, blood and renal metabolism of lactating dairy cows. Sixteen Holstein cows were distributed in four contemporary 4×4 Latin Square designs, which consisted of four periods of 21 days and four treatments according to DCAD: +290; +192; +98 and -71 milliequivalent (mEq)/kg dry matter (DM). Ruminal pH and concentrations of acetic and butyric acid increased linearly according to the increase of DCAD. Similarly, NDF total apparent digestibility linearly increased by 6.38% when DCAD increased from -71 to 290 mEq/kg DM [Y=65.90 (SE=2.37)+0.0167 (SE=0.0068)×DCAD (mEq/kg DM)]. Blood pH was also increased according to DCAD, which resulted in reduction of serum concentrations of Na, K and ionic calcium (iCa). To maintain the blood acid-base homeostasis, renal metabolism played an important role in controlling serum concentrations of Na and K, since the Na and K urinary excretion increased linearly by 89.69% and 46.06%, respectively, from -71 to 290 mEq/kg DM. Changes in acid-base balance of biological fluids may directly affect the mineral composition of milk, as milk concentrations of Na, K, iCa and chlorides were reduced according to blood pH increased. Thus, it can be concluded that the increase of DCAD raises the pH of ruminal fluid, NDF total apparent digestibility, and blood pH, and decreases the milk concentration of cationic minerals, as well as the efficiency of Na utilization to milk production. PMID:26289745

  19. Influence of stimulation by electroejaculation on myocardial function, acid-base and electrolyte status, and hematobiochemical profiles in male dromedary camels.

    Tharwat, M; Ali, A; Al-Sobayil, F; Derar, R; Al-Hawas, A

    2014-10-01

    This study was carried out to evaluate the effect of electroejaculation (EEJ) on myocardial function, acid-base balance, and hematobiochemical profiles in male dromedary camels. Twenty sexually mature, apparently healthy male camels were assigned to EEJ. Parallel, eight naturally mated male camels were enrolled as a control group. Three blood samples were collected from each camel: just before (T0), directly after (T1), and 24 hours after (T2) EEJ or natural mating. The serum concentrations of the cardiac biomarker troponin I (cTnI), blood gas parameters, and hematobiochemical profiles were determined. Nineteen camels were ejaculated by the end of the second circuit and one by the end of the first circuit. In both groups, the mean heart and respiratory rates had increased significantly immediately after the procedure, but returned to normal values 24 hours after the procedure. The mean serum concentration of cTnI had increased significantly in all camels after EEJ, but not in controls. However, at 24 hours post-EEJ, the serum concentration of cTnI did not differ significantly compared with baseline values. The blood pH and base excess had decreased, and the PCO2 and lactic acid had increased after EEJ. The EEJ provoked decreases in hematocrit and mean corpuscular volume. In the control group, the base excess, HCO3(-), TCO2, anion gap, and lactic acid increased slightly after mating but did not reach a significant level compared with premating values. It is concluded that EEJ in camels results in a reversible myocardial injury, changes in the acid-base status, and increase the lactic acid concentration. PMID:25139755

  20. Finding Your Balance

    (CCL), Center for Creative Leadership; Patterson, Gordon

    2011-01-01

    Balance isn't an issue of time, but an issue of choice. It's about living your values by aligning your behavior with what you believe is really important. Aligning your behavior with your values is much like any other developmental experience; the basic process involves assessment, challenge, and support. You need to determine where you are, define where you want to go, and then put into place the tools you need to get there.Balance is about more than how you spend your time. It's about how you live your life. It's about recognizing that you have control over the choices you make and aligning

  1. Getting the balance right

    This 8 page leaflet is published by the Nuclear Electricity Information Group (NEIG) which is made up of eight different bodies working within the nuclear industry. It aims to present a balanced outline of the facts needed to form an opinion about energy policy in the UK. It looks at the price of electricity, other sources of electricity, (oil and coal, solar power, wind power, water power), safety in the nuclear industry, nuclear waste disposal and risks from radiation. The NEIG is in favour of a balanced energy programme with nuclear energy being only a part of the overall scheme. (U.K.)

  2. Aplikace Balanced Scorecard

    Jaroměřská, Martina

    2015-01-01

    This master's thesis deals with application of the Balanced Scorecard method to Němcova selská mlékárna Radonice, spol. s.r.o. The goal is to analyse the strategic position of the company and propose a new company strategy. Further, the strategic goals defined by the strategy are converted to a strategic map to clearly show causality relationships between the goals of the four perspectives of the Balanced Scoreboard method. The strategic goals are assigned measures and target values and initi...

  3. A balanced team generating model

    van de Water, Tara; van de Water, Henny; Bukman, Cock

    2007-01-01

    This paper introduces a general team balancing model. It first summarizes existing balancing methods. It is shown that for these methods it is difficult to meet all the conditions posed by Belbin on balanced teams. This mainly is caused by the complexity of the balancing problem. A mathematical mode

  4. Toward Balance in Translation.

    Costello, Nancy A.

    A study compared translations of biblical passages into different languages in Papua New Guinea. The study looked for evidence of balance between literal and free interpretation in translation style in the gospel of Mark, which is narrative and didactic material, in 12 languages, and the mainly hortatory genre in translations of 4 epistles:…

  5. National energy balance - 1977

    The national energy balance of the 1976 shows several modifications in relation to the last year. The historical serie is based in more confiable information, from several energy companies. The most greater modifications are on energy source of hard control, such as lignite and charcoal for non-siderurgic uses. (E.G.)

  6. Yin-Yang Balancing

    Li, Peter Ping

    The potential contribution of the Eastern frame of Yin-Yang Balancing lies in the mindset of "either/and", in contrast to Aristotle's either/or logic and Hegel's "both/or". Implications of this either/and thinking for science and management will be explored....

  7. National energy balance - 1978

    The national energy balance of 1978 shows some modifications in relation to the last year. New tables were included aiming to show the brazilian energy situation, such as the hydraulic potential and the non-renewable energy resources. (E.G.)

  8. National Energy Balance - 1986

    The National Energy Balance - 1986 shows energy fluxes of several primary and secondary energy sources, since the production to the final consumption in the main economic sectors, since 1970 to 1985. The incorporation of a new brazilian information is done. (E.G.)

  9. National Energy Balance - 1981

    The National Energy Balance - 1981, shows a new metodology and information in level of several economic sectors, as well as a separation of primary and secondary energy sources, its energy fluxes, i.e. production, imports, exports, consumption, etc...(E.G.)

  10. Lives in the Balance.

    Our Children, 1997

    1997-01-01

    Changes in the workplace that would provide flexibility for working parents are slowly developing and receiving government, business, and societal attention. A sidebar, "Mother, Professional, Volunteer: One Woman's Balancing Act," presents an account of how one woman rearranged her professional life to enable her to do full-time parenting. (SM)

  11. Regulation of Energy Balance.

    Bray, George A.

    1985-01-01

    Explains relationships between energy intake and expenditure focusing on the cellular, chemical and neural mechanisms involved in regulation of energy balance. Information is referenced specifically to conditions of obesity. (Physicians may earn continuing education credit by completing an appended test). (ML)

  12. Hypoxia and Its Acid-Base Consequences: From Mountains to Malignancy.

    Swenson, Erik R

    2016-01-01

    Hypoxia, depending upon its magnitude and circumstances, evokes a spectrum of mild to severe acid-base changes ranging from alkalosis to acidosis, which can alter many responses to hypoxia at both non-genomic and genomic levels, in part via altered hypoxia-inducible factor (HIF) metabolism. Healthy people at high altitude and persons hyperventilating to non-hypoxic stimuli can become alkalotic and alkalemic with arterial pH acutely rising as high as 7.7. Hypoxia-mediated respiratory alkalosis reduces sympathetic tone, blunts hypoxic pulmonary vasoconstriction and hypoxic cerebral vasodilation, and increases hemoglobin oxygen affinity. These effects and others can be salutary or counterproductive to tissue oxygen delivery and utilization, based upon magnitude of each effect and summation. With severe hypoxia either in the setting of profound arterial hemoglobin desaturation and reduced O2 content or poor perfusion (ischemia) at the global or local level, metabolic and hypercapnic acidosis develop along with considerable lactate formation and pH falling to below 6.8. Although conventionally considered to be injurious and deleterious to cell function and survival, both acidoses may be cytoprotective by various anti-inflammatory, antioxidant, and anti-apoptotic mechanisms which limit total hypoxic or ischemic-reperfusion injury. Attempts to correct acidosis by giving bicarbonate or other alkaline agents under these circumstances ahead of or concurrent with reoxygenation efforts may be ill advised. Better understanding of this so-called "pH paradox" or permissive acidosis may offer therapeutic possibilities. Rapidly growing cancers often outstrip their vascular supply compromising both oxygen and nutrient delivery and metabolic waste disposal, thus limiting their growth and metastatic potential. However, their excessive glycolysis and lactate formation may not necessarily represent oxygen insufficiency, but rather the Warburg effect-an attempt to provide a large amount

  13. Acid-base behavior in hydrothermal processing of wastes. 1997 annual progress report

    'A major obstacle to the development of hydrothermal technology for treating DOE wastes has been a lack of scientific knowledge of solution chemistry, thermodynamics and transport phenomena. The progress over the last year is highlighted in the following four abstracts from manuscripts which have been submitted to journals. The authors also have made considerable progress on a spectroscopic study of the acid-base equilibria of Cr(VI). They have utilized novel spectroscopic indicators to study acid-base equilibria up to 380 C. Until now, very few systems have been studied at such high temperatures, although this information is vital for hydrothermal processing of wastes. The pH values of aqueous solutions of boric acid and KOH were measured with the optical indicator 2-naphthol at temperatures from 300 to 380 C. The equilibrium constant Kb-l for the reaction B(OH)3 + OH- = B(OH)-4 was determined from the pH measurements and correlated with a modified Born model. The titration curve for the addition of HCl to sodium borate exhibits strong acid-strong base behavior even at 350 C and 24.1 MPa. At these conditions, aqueous solutions of sodium borate buffer the pH at 9.6 t 0.25. submitted to Ind. Eng. Chem. Res. Acetic Acid and HCl Acid-base titrations for the KOH-acetic acid or NH3 -acetic acid systems were monitored with the optical indicator 2-naphthoic acid at 350 C and 34 MPa, and those for the HCl;Cl- system with acridine at 380 C and up to 34 MPa (5,000 psia ). KOH remains a much stronger base than NH,OH at high temperature. From 298 K to the critical temperature of water, the dissociation constant for HCl decreases by 13 orders of magnitude, and thus, the basicity of Cl- becomes significant. Consequently, the addition of NaCl to HCl raises the pH. The pH titration curves may be predicted with reasonable accuracy from the relevant equilibrium constants and Pitzer''s formulation of the Debye- Htickel equation for the activity coefficients.'

  14. Enabling the Tablet Product Development of 5-Fluorocytosine by Conjugate Acid Base Cocrystals.

    Perumalla, Sathyanarayana R; Paul, Shubhajit; Sun, Changquan C

    2016-06-01

    5-Fluorocytosine (FC) is a high-dose antifungal drug that challenges the development of a tablet product due to poor solid-state stability and tabletability. Using 2 pharmaceutically acceptable conjugate acid base (CAB) cocrystals of FC with HCl and acesulfame, we have developed commercially viable high loading FC tablets. The tablets were prepared by direct compression using nano-coated microcrystalline cellulose Avicel PH105 as a tablet binder, which provided both excellent tabletability and good flowability. Commercial manufacturability of formulations based on both CAB cocrystals was verified on a compaction simulator. The results from an expedited friability study were used to set the compaction force, which yielded tablets with sufficient mechanical strength and rapid tablet disintegration. This work demonstrates the potential value of CAB cocrystals in drug product development. PMID:27238493

  15. Unimolecular half-adders and half-subtractors based on acid-base reaction

    Wei JIANG; Hengyi ZHANG; Yu LIU

    2009-01-01

    According to the structural analysis of reported mole-cular processors with acids and bases as inputs, we proposed a general method for constructing molecular half-adders and/or half-subtractors based on acid-base reaction. The method is preliminarily supported by four molecular processors (8-hydroxyquinoline, 4-hydroxypyridine, 4-aminophenol and 5-amino-1-naphthol) capable of the elementary addition and/or subtraction algebraic operations. Noticeably, 8-hydroxyquinoline can mimic the functions of three logic devices, i.e. half-adder, half-subtractor and digital comparator, by the use of superposition and reconfi-guration. The method described in this paper may be useful not only for designing new unimolecular arithmetical processors with the same inputs and outputs as standard devices for the construction of future molecular computers, but it can also help us disclose the simplest molecules and biomolecules with computational properties concealed around us.

  16. Role of acid-base interactions in synthesis of cordierite from talc and sillimanite group minerals

    Avvakumov E.G.

    2013-01-01

    Full Text Available It has been found that the mechanical activation of mixtures of sillimanite group minerals with talc and silica additives in grinding-activating devices with periodic and flow action provides significant acceleration of their interaction with formation of cordierite at the subsequent high-temperature treatment. It is shown that the output of cordierite depends on nature of mineral: in mixture with a sillimanite it is considerably higher, than with an andalusite and kyanite, while the rate of mullitization of these minerals has opposite character. It means that the formation of mullite during heat treatment is not a limiting step in synthesis of cordierite. It is shown that the rate of reaction is determined by the difference in the acid-base properties of these minerals, which depend on the coordination of aluminum cations by oxygen ions, different for each of the modifications.

  17. Laser restoring the glass surface treated with acid-based paint

    Strusevich, Anastasia V.; Poltaev, Yuriy A.; Sinev, Dmitrii A.

    2013-11-01

    The modern city facilities are often being attacked by graffiti artists, and increasingly vandals leave "tags" using paints, which compound based on acids, hydrofluoric or acetic commonly. These paints not only ink the surface, but also increase the surface roughness, and such impact can not be corrected by conventional cleaning. Thus, it was requested to develop technology that would not only clean the surface, but also to restore its structure by smoothing out irregularities and roughness formed after exposure in acid. In this work we investigated the effect of restoring the surface of the glass, spoiled by acid-based paint and then treated with CO2-laser. During the experiments, it was found that it is real to create the single-step laser surface restoring technology.

  18. Identification and Optimization of Anthranilic Acid Based Inhibitors of Replication Protein A.

    Patrone, James D; Pelz, Nicholas F; Bates, Brittney S; Souza-Fagundes, Elaine M; Vangamudi, Bhavatarini; Camper, Demarco V; Kuznetsov, Alexey G; Browning, Carrie F; Feldkamp, Michael D; Frank, Andreas O; Gilston, Benjamin A; Olejniczak, Edward T; Rossanese, Olivia W; Waterson, Alex G; Chazin, Walter J; Fesik, Stephen W

    2016-04-19

    Replication protein A (RPA) is an essential single-stranded DNA (ssDNA)-binding protein that initiates the DNA damage response pathway through protein-protein interactions (PPIs) mediated by its 70N domain. The identification and use of chemical probes that can specifically disrupt these interactions is important for validating RPA as a cancer target. A high-throughput screen (HTS) to identify new chemical entities was conducted, and 90 hit compounds were identified. From these initial hits, an anthranilic acid based series was optimized by using a structure-guided iterative medicinal chemistry approach to yield a cell-penetrant compound that binds to RPA70N with an affinity of 812 nm. This compound, 2-(3- (N-(3,4-dichlorophenyl)sulfamoyl)-4-methylbenzamido)benzoic acid (20 c), is capable of inhibiting PPIs mediated by this domain. PMID:26748787

  19. Thermodynamics of several lewis-acid-base stabilized transition metal alloys

    Gibson, John K.; Brewer, Leo; Gingerich, Karl A.

    1984-11-01

    High-temperature (1425 to 2750 K) thermodynamic activities of one or both components of twenty-five binary alloys of a group IVB-VIB element (Ti, Zr, Hf, Nb, Ta, or W) with a platinum group element (Ru, Os, Ir, Pd, Pt, or Au) have been determined by equilibrating the alloy with the appropriate carbide and graphite, equilibrating with the nitride and nitrogen gas, or measuring the partial vapor pressure(s) thermogravimetrically or mass spectrometrically. The extraordinary stability of this class of transition metal alloy is attributed to a generalized Lewis-acid-base interaction involving valence d electrons, and the results of these investigations are interpreted within the context of this effect. Among the conclusions made are that a non-spherically-symmetrical crystal field significantly reduces the bonding effectiveness of certain valence d orbitals; the effect of the extent of derealization of these orbitals is also considered.

  20. Chemical composition and the acid-base properties of the InSb-ZnSe surface

    Acid-base properties and chemical composition of the surface of solid solutions and binary compounds of the system InSb-ZnSe powders and films 0.25-0.35 μm thick were studied using a complex of physicochemical methods. It was ascertained that the initial surface features largely acid properties with transition to low-basic ones in the series InSb → (InSb)x(ZnSe)1-x → ZnSe. There are two types of acid centers on the surface: the Lewis (electron-accepted) and Broensted ones (adsorbed water molecules and OH- groups). After thermal vacuum treatment the surface composition was similar to stoichiometric one

  1. Neural networks applied to determine the thermophysical properties of amino acid based ionic liquids.

    Cancilla, John C; Perez, Ana; Wierzchoś, Kacper; Torrecilla, José S

    2016-03-01

    A series of models based on artificial neural networks (ANNs) have been designed to estimate the thermophysical properties of different amino acid-based ionic liquids (AAILs). Three different databases of AAILs were modeled using these algorithms with the goal set to estimate the density, viscosity, refractive index, ionic conductivity, and thermal expansion coefficient, and requiring only data regarding temperature and electronic polarizability of the chemicals. Additionally, a global model was designed combining all of the databases to determine the robustness of the method. In general, the results were successful, reaching mean prediction errors below 1% in many cases, as well as a statistically reliable and accurate global model. Attaining these successful models is a relevant fact as AAILs are novel biodegradable and biocompatible compounds which may soon make their way into the health sector forming a part of useful biomedical applications. Therefore, understanding the behavior and being able to estimate their thermophysical properties becomes crucial. PMID:26899458

  2. Using balance program for energy balance analysis

    Belong with development of the economy, the energy consumption will be increased very high in the future. Vietnam has a broad range of mineral resources. There is considerable energy potential on form of coal, oil and gas, hydropower and fuel wood, Recently, Vietnam is an exporter of energy. But in next two decades, the energy sources will be enough to meet requirement? The model BALANCE was used to solve energy planning problem. The objective of this model is analyzing energy system and built an energy development strategy in long term. After using model, the results are: total coal consumption will be 17.440 Mtoe in 2020 and 32 Mtoe in 2030. the biggest coal consumer is electricity sector. Total oil production consumption will be more than 30 Mtoe in 2020 and more than 50 Mtoe in 2030. If we have 4 refinery factories from now to 2030, total oil products import will be 11 Mtoe in 2020 and 25 Mtoe in 2030. The amount of gas supply in 2030 will be 20 billions m3 (18 Mtoe). Vietnam needs to import 8.3 Mtoe more, Vietnam will become an energy importer in next 15 years. In previous years, the economy of Vietnam was mainly based on agricultural production. But Vietnam is moving rapidly from an agricultural to an industrial economy. Belong with the development of the economy, energy consumption increases very fast. So which energy sources should be used first and when it will be use...are questions need to be answered. Vietnam has a broad range of mineral resources. There is considerable energy potential on form of coal, oil and gas, hydropower and fuel wood. Recently, Vietnam is energy exporter, but in near future Vietnam has enough energy to meet demand or we need to import from outside? It should be studied carefully to answer. (author)

  3. Energy balances 2001

    Denmark's consumption of energy increased 1,6 % from 2000 to 2001, primarily due to the year 2001 being colder than the year 2000. The production of petroleum decreased from 2000 to 2001, the reason being an accident at the Gorm oil field. The production of renewable energy and natural gas, however, increased. The energy balances is an account of production, import and export, and consumption of energy. The consumption is presented for households and industry. In the energy balances the energy consumption is accounted as physical amounts as well as gross consumption. Also an account is made of the costs of energy in basis prices and in market prices, including calculation of excises on energy, CO2 and SO2. (ln)

  4. France's energy balances

    Several terminological definitions of words and concepts used for the establishment of France's energy balance (i.e. the supply and utilization of energy) are presented, taken from the Energy dictionary, published in 1992 by the world Energy Council: primary, secondary, final and useful energy. Statistics concerning energy production, importation and exportation, consumption, and costs are discussed, showing the market share evolution of the different energy types; the France's energy independence ratio has increased from 22% in 1973 to 51% in 1995

  5. An ideal balance?

    Mair, Jane

    2013-01-01

    Considers the intersection between employment policy and family law, and the changes in work and family regarding traditional gender roles. Examines UK and EU policy initiatives aimed at achieving a better work/life balance for employees with children. Argues that many of the policy aspirations are predicated on an equal opportunities employment model that may not exist in practice and also fail to reflect the realities of family life.

  6. Balance-bot

    Abreu, Victor Vicente

    2009-01-01

    Research on inverted pendulum has gained momentum over the last decade on a number of robotic laboratories over the world; due to its unstable proprieties is a good example for control engineers to verify a control theory. To verify that the pendulum can balance we can make some simulations using a closed-loop controller method such as the linear quadratic regulator or the proportional–integral–derivative method. Also the idea of robotic teleoperation is gaining ground. Control...

  7. Ballet Balance Strategies

    Pedersen, Camilla; Erleben, Kenny; Sporring, Jon

    2006-01-01

    Animating physically realistic human characters is challenging, since human observers are highly tuned to recognize human cues such as emotion and gender from motion patterns. The main contribution of this paper is a new model firmly based on biomechanics, which is used to animate balance and basic movements of a ballet dancers. It is supported by computer simulated experiments and it is in good agreement with biomechanical measurements of real-life dancers. Our results questions the previous...

  8. National energy balance - 1976

    Based on available data from IBGE, CNP/Petrobras, Eletrobras, Nuclebras and other governmental enterprises the National Energy Balance was done. This publication covers since 1965 to 1975. In conformity to the international rules, the energy resources used for non-energy purposes were excluded. The energy production and consumption for the next ten years were forecasted, considering the actual brazilian energy policy. (E.G.)

  9. Finance and Balanced Growth

    Trew, Alex

    2010-01-01

    We study the relationships between various concepts of financial development and balanced economic growth. A model of endogenous growth that incorporates roles for both financial efficiency and access to financial services permits a better understanding of the relationship between the size of the financial sector (value added) and growth. Higher financial value added results from some, but not all, kinds of finance-driven growth. If greater access rather than greater efficiency generates high...

  10. In the balance

    Kluth, Michael Friederich; Pilegaard, Jess

    The present paper seeks to make sense of recent EU naval capability changes by applying neo-realist theory on the EU as an international actor in the global balance of power. The paper compares three different strands of Neo-realist theory by deducting key predictions about the expected defense...... strategy aimed at bolstering the autonomy and international influence of the Union, vis-à-vis other major powers, including the United States....

  11. Thinking About Competitive Balance

    Allen R. Sanderson; John J. Siegfried

    2003-01-01

    Simon Rottenberg long ago noted that the nature of sports is such that competitors must be of approximately equal ability if any are to be financially successful. In recent years, sports commentators and fans, Major League Baseball itself, and even some economists have expressed growing concern about the widening disparities among team expenditures and the growing concentrations of postseason contenders and championships. In this article we compare different concepts of competitive balance, r...

  12. Simple Cell Balance Circuit

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  13. Gait and balance disorders.

    Masdeu, Joseph C

    2016-01-01

    This chapter focuses on one of the most common types of neurologic disorders: altered walking. Walking impairment often reflects disease of the neurologic structures mediating gait, balance or, most often, both. These structures are distributed along the neuraxis. For this reason, this chapter is introduced by a brief description of the neurobiologic underpinning of walking, stressing information that is critical for imaging, namely, the anatomic representation of gait and balance mechanisms. This background is essential not only in order to direct the relevant imaging tools to the regions more likely to be affected but also to interpret correctly imaging findings that may not be related to the walking deficit object of clinical study. The chapter closes with a discussion on how to image some of the most frequent etiologies causing gait or balance impairment. However, it focuses on syndromes not already discussed in other chapters of this volume, such as Parkinson's disease and other movement disorders, already discussed in Chapter 48, or cerebellar ataxia, in Chapter 23, in the previous volume. As regards vascular disease, the spastic hemiplegia most characteristic of brain disease needs little discussion, while the less well-understood effects of microvascular disease are extensively reviewed here, together with the imaging approach. PMID:27430451

  14. Controlled synthesis of multi-morphology Te crystals by a convenient Lewis acid/base-assisted solvothermal method

    This paper reports on the controlled growth of multi-morphology Te crystals by a convenient Lewis acid/base-assisted solvothermal method for the first time. The morphological transformation from one-dimension (1D) nanostructures to 2D hierarchical flowerlike microarchitecture has been observed. The nanorods and nanowires with a well-defined crystallographical structure and the hierarchical flowers microarchitecture were obtained by changing the Lewis acids/bases. Lewis acids/bases were found to be crucial for the formation of the products by not only acting as the pH regulator but also as the shape controller, owing to their hydrolysis in the solvent to in situ form H+/OH− and hydrates. The results suggest that this should be an effective approach to the control the growth of t-Te crystals with interesting multiple morphologies, which are of interest for both theoretical investigations and practical applications.

  15. Analysis of the low-pressure plasma pretreated polymer surface in terms of acid-base approach

    Kraus, Eduard; Orf, Lukas; Baudrit, Benjamin; Heidemeyer, Peter; Bastian, Martin; Bonenberger, Ramona; Starostina, Irina; Stoyanov, Oleg

    2016-05-01

    We demonstrate the use of a modern wetting method for determining the acid-base properties of treated polymer surfaces for different plastics and adhesives. The effect of the surface treatment with low pressure plasma was evaluated from the viewpoint of acid-base approach with plastics polyoxymethylene (POM) and polyetheretherketone (PEEK). The correlations between the acid-base properties and the identified mechanical tensile strengths of adhesive bonded joints were evaluated and discussed. In the investigated range the determination coefficients for POM and PEEK were calculated to R2 = 0.93 and R2 = 0.97, respectively. These relatively high determination coefficients showed a good correlation between the mechanical strength and the acidity parameter ΔDshort for use in bonding technology for surface pretreatment of polymers with LPP.

  16. EFFECTS OF BROILER REARING ENVIRONMENT ON TRANSMISSION OF F-STRAIN MYCOPLASMA GALLISEPTICUM FROM COMMERCIAL LAYER HENS TO BROILER CHICKENS: ROLE OF ACID-BASE BALANCE

    Two trials were conducted concurrently to determine and compare, blood pH, blood gases, hematocrit, and hemoglobin in mycoplasma-free, F-strain Mycoplasma gallisepticum (FMG) inoculation layers, and FMG contact-infected broilers. FMG-inoculated layers had the highest partial pressure of O2 and the l...

  17. Effects of single and combined Mycoplasma gallisepticums vaccinations on blood electrolytes and acid-base balance in commercial egg-laying hens

    In a previous study, it was shown to occur in response to an F-strain Mycoplasma gallisepticum (FMG) inoculation layers from our laboratory a significant increase in arterial partial pressure of oxygen (pO2), which is generally associated with an oxygen-dependent improvement in tissue oxygenation to...

  18. Balanced skills among nascent entrepreneurs

    Stuetzer, Michael; Obschonka, Martin; Schmitt-Rodermund, Eva

    2012-01-01

    This paper examines the effects and origins of balanced skills among nascent entrepreneurs. In a first step we apply Lazear’s jack-of-all-trades theory to investigate performance effects of a balanced skill set. Second, we investigate potential sources of balanced skills, thereby testing the investment hypothesis against the endowment hypothesis. Analyzing data on high-potential nascent projects, we find support for the notion that balanced skills are important for making progress in the vent...

  19. Continuous Renal Replacement Therapy for the Management of Acid-Base and Electrolyte Imbalances in Acute Kidney Injury.

    Yessayan, Lenar; Yee, Jerry; Frinak, Stan; Szamosfalvi, Balazs

    2016-05-01

    Continuous renal replacement therapy (CRRT) is used to manage electrolyte and acid-base imbalances in critically ill patients with acute kidney injury. Although a standard solution and prescription is acceptable in most clinical circumstances, specific disorders may require a tailored approach such as adjusting fluid composition, regulating CRRT dose, and using separate intravenous infusions to mitigate and correct these disturbances. Errors in fluid prescription, compounding, or delivery can be rapidly fatal. This article provides an overview of the principles of acid-base and electrolyte management using CRRT. PMID:27113697

  20. α-Gel formation by amino acid-based gemini surfactants.

    Sakai, Kenichi; Ohno, Kiyomi; Nomura, Kazuyuki; Endo, Takeshi; Sakamoto, Kazutami; Sakai, Hideki; Abe, Masahiko

    2014-07-01

    Ternary mixtures being composed of surfactant, long-chain alcohol, and water sometimes form a highly viscous lamellar gel with a hexagonal packing arrangement of their crystalline hydrocarbon chains. This molecular assembly is called "α-crystalline phase" or "α-gel". In this study, we have characterized α-gels formed by the ternary mixtures of amino acid-based gemini surfactants, 1-hexadecanol (C16OH), and water. The surfactants used in this study were synthesized by reacting dodecanoylglutamic acid anhydride with alkyl diamines and abbreviated as 12-GsG-12 (s: the spacer chain length of 2, 5, and 8 methylene units). An amino acid-based monomeric surfactant, dodecanoylglutamic acid (12-Glu), was also used for comparison. At a fixed water concentration the melting point of the α-gel increased with increasing C16OH concentration, and then attained a saturation level at the critical mole ratio of 12-GsG-12/C16OH = 1/2 under the normalization by the number of hydrocarbon chains of the surfactants. This indicates that, to obtain the saturated α-gel, a lesser amount of C16OH is required for the gemini surfactants than for the monomeric one (the critical mole ratio of 12-Glu/C16OH = 1/3). Small- and wide-angle X-ray scattering measurements demonstrated an increase in the long-range d-spacing of the saturated α-gels in the order 12-Glu gemini surfactant systems, the decreased spacer chain length resulted in the increased maximum viscosity and elastic modulus of the saturated α-gels at a given water concentration. This is caused by the decreased amount of excess water being present outside the α-gel structure (or the increased amount of water incorporated between the surfactant-alcohol bilayers). To the best of our knowledge, this is the first report focusing on the formation of α-gel in gemini surfactant systems. PMID:24912111

  1. Comparative bioavailability studies of citric acid and malonic acid based aspirin effervescent tablets

    Anju Gauniya

    2010-01-01

    Full Text Available Purpose: The present investigation is aimed at comparing the pharmacokinetic profile (Bioavailability of aspirin in tablet formulations, which were prepared by using different effervescent excipients such as citric acid and malonic acid. Materials and Methods: The relative bioavailability and pharmacokinetics of citric acid based aspirin effervescent tablet (Product A and malonic acid based aspirin effervescent tablet (Product B formulations were evaluated for an in-vitro dissolution study and in-vivo bioavailability study, in 10 normal healthy rabbits. The study utilized a randomized, crossover design with a one-week washout period between doses. Blood samples were collected at 0, 1, 2, 4, 6, 8, 12 and 24 hours following a 100 mg/kg dose. Plasma samples were assayed by High Performance Liquid Chromatography. T max , C max , AUC 0-24 , AUC 0- ∞, MRT, K a, and relative bioavailability were estimated using the traditional pharmacokinetic methods and were compared by using the paired t-test. Result: In the present study, Products A and B showed their T max , C max , AUC 0-24 , AUC 0- ∞, MRT, and K a values as 2.5 h, 2589 ± 54.79 ng/ml, 9623 ± 112.87 ng.h/ml, 9586 ± 126.22 ng.h/ml, 3.6 ± 0.10 h, and 0.3698 ± 0.003 h -1 for Product A and 3.0 h, 2054 ± 55.79 ng/ml, 9637 ± 132.87 ng.h/ml, 9870 ± 129.22 ng.h/ml, 4.76 ± 0.10 h, and 0.3812 ± 0.002 h -1 for Product B, respectively. Conclusion: The results of the paired t-test of pharmacokinetics data showed that there was no significant difference between Products A and B. From both the in vitro dissolution studies and in vivo bioavailability studies it was concluded that products A and B had similar bioavailability.

  2. Acidic deposition: State of science and technology. Report 10. Watershed and lake processes affecting surface-water acid-base chemistry. Final report

    The acid-base chemistry of surface waters is governed by the amount and chemistry of deposition and by the biogeochemical reactions that generate acidity or acid neutralizing capacity (ANC) along the hydrologic pathways that water follows through watersheds to streams and lakes. The amount of precipitation and it chemical loading depend on the area's climate and physiography, on it proximity to natural or industrial gaseous or particulate sources, and on local or regional air movements. Vegetation interacts with the atmosphere to enhance both wet and dry deposition of chemicals to a greater or lesser extent, depending on vegetation type. Vegetation naturally acidifies the environment in humid regions through processes of excess base cation uptake and generation of organic acids associated with many biological processes. Natural acid production and atmospheric deposition of acidic materials drive the acidification process. The lake or stream NAC represents a balance between the acidity-and ANC-generating processes that occur along different flow paths in the watershed and the relative importance of each flow path

  3. Solubility and modeling acid-base properties of adrenaline in NaCl aqueous solutions at different ionic strengths and temperatures.

    Bretti, Clemente; Cigala, Rosalia Maria; Crea, Francesco; De Stefano, Concetta; Vianelli, Giuseppina

    2015-10-12

    Solubility and acid-base properties of adrenaline were studied in NaCl aqueous solutions at different ionic strengths (0solubility of the ligand was calculated from simple mass balance equations, by using the free hydrogen concentration and the protonation constants of the ligand determined in the same experimental conditions of the solubility measurements. The salting-In or Out parameters and the activity coefficient of the neutral species were calculated by means of the Setschenow equation. The dependence of the protonation constants on the ionic strength was modeled by means of the Debye-Hückel type equation and of the SIT (Specific ion Interaction Theory) approach. The specific interaction parameters of the ion pairs were also reported. For the protonation constants, the following thermodynamic values at infinite dilution were obtained: T=298.15 K, logK1(H0)=10.674±0.018 and logK2(H0)=8.954±0.022; T=310.15K, logK1(H0)=10.355±0.018 and logK2(H0)=8.749±0.030. PMID:26122929

  4. Lesson "Balance in Nature

    Chapanova, V.

    2012-04-01

    Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

  5. Balancing innovation and evidence.

    Pilcher, Jobeth W

    2015-01-01

    Nurse educators are encouraged to use evidence to guide their teaching strategies. However, evidence is not always available. How can educators make decisions regarding strategies when data are limited or absent? Where do innovation and creativity fit? How can innovation be balanced with evidence? This article provides a discussion regarding other sources of evidence, such as extrapolations, theories and principles, and collective expertise. Readers are encouraged to review the options and then analyze how they might be applied to innovation in education. PMID:25790361

  6. Watt and joule balances

    Robinson, Ian A.

    2014-04-01

    The time is fast approaching when the SI unit of mass will cease to be based on a single material artefact and will instead be based upon the defined value of a fundamental constant—the Planck constant—h . This change requires that techniques exist both to determine the appropriate value to be assigned to the constant, and to measure mass in terms of the redefined unit. It is important to ensure that these techniques are accurate and reliable to allow full advantage to be taken of the stability and universality provided by the new definition and to guarantee the continuity of the world's mass measurements, which can affect the measurement of many other quantities such as energy and force. Up to now, efforts to provide the basis for such a redefinition of the kilogram were mainly concerned with resolving the discrepancies between individual implementations of the two principal techniques: the x-ray crystal density (XRCD) method [1] and the watt and joule balance methods which are the subject of this special issue. The first three papers report results from the NRC and NIST watt balance groups and the NIM joule balance group. The result from the NRC (formerly the NPL Mk II) watt balance is the first to be reported with a relative standard uncertainty below 2 × 10-8 and the NIST result has a relative standard uncertainty below 5 × 10-8. Both results are shown in figure 1 along with some previous results; the result from the NIM group is not shown on the plot but has a relative uncertainty of 8.9 × 10-6 and is consistent with all the results shown. The Consultative Committee for Mass and Related Quantities (CCM) in its meeting in 2013 produced a resolution [2] which set out the requirements for the number, type and quality of results intended to support the redefinition of the kilogram and required that there should be agreement between them. These results from NRC, NIST and the IAC may be considered to meet these requirements and are likely to be widely debated

  7. Die Balance der Verantwortung

    Abt, Andreas

    2006-01-01

    Die Balance der Verantwortung Ein Modell der Pädagogik zur Entwicklung von Verantwortungsfähigkeit Diese Arbeit befasst sich mit dem Begriff der Verantwortung, der in der Gesellschaft häufig verwendet wird und dort in der Regel positiv belegt ist. Neben der Vorstellung einer modernen Begriffsinterpretation lege ich die Bedeutung des Themas Verantwortung für die menschliche Existenz und damit auch für die Themen Erziehung und Bildung dar. Ausgehend von der Frage, warum Menschen in der d...

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

    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. PMID:20013742

  9. A facile nanoaggregation strategy for oral delivery of hydrophobic drugs by utilizing acid base neutralization reactions

    Chen, Huabing; Wan, Jiangling; Wang, Yirui; Mou, Dongsheng; Liu, Hongbin; Xu, Huibi; Yang, Xiangliang

    2008-09-01

    Nanonization strategies have been used to enhance the oral availability of numerous drugs that are poorly soluble in water. Exploring a facile nanonization strategy with highly practical potential is an attractive focus. Here, we report a novel facile nanoaggregation strategy for constructing drug nanoparticles of poorly soluble drugs with pH-dependent solubility by utilizing acid-base neutralization in aqueous solution, thus facilitating the exploration of nanonization in oral delivery for general applicability. We demonstrate that hydrophobic itraconazole dissolved in acid solution formed a growing core and aggregated into nanoparticles in the presence of stabilizers. The nanoparticles, with an average diameter of 279.3 nm and polydispersity index of 0.116, showed a higher dissolution rate when compared with the marketed formulation; the average dissolution was about 91.3%. The in vivo pharmacokinetic studies revealed that the nanoparticles had a rapid absorption and enhanced oral availability. The diet state also showed insignificant impact on the absorption of itraconazole from nanoparticles. This nanoaggregation strategy is a promising nanonization method with a facile process and avoidance of toxic organic solvents for oral delivery of poorly soluble drugs with pH-dependent solubility and reveals a highly practical potential in the pharmaceutical and chemical industries.

  10. Stearic acid based oleogels: a study on the molecular, thermal and mechanical properties.

    Sagiri, S S; Singh, Vinay K; Pal, K; Banerjee, I; Basak, Piyali

    2015-03-01

    Stearic acid and its derivatives have been used as gelators in food and pharmaceutical gel formulations. However, the mechanism pertaining to the stearic acid based gelation has not been deciphered yet. Keeping that in mind, we investigated the role of stearic acid on physic-chemical properties of oleogel. For this purpose, two different oil (sesame oil and soy bean oil) formulations/oleogels were prepared. In depth analysis of gel kinetics, gel microstructure, molecular interactions, thermal and mechanical behaviors of the oleogels were done. The properties of the oleogels were dependent on the type of the vegetable oil used and the concentration of the stearic acid. Avrami analysis of DSC thermograms indicated that heterogeneous nucleation was coupled with the one-dimensional growth of gelator fibers as the key phenomenon in the formation of oleogels. Viscoelastic and pseudoplastic nature of the oleogels was analyzed in-depth by fitting the stress relaxation data in modified Peleg's model and rheological studies, respectively. Textural studies have revealed that the coexistence of hydrogen bond dissipation and formation of new bonds is possible under stress conditions in the physical oleogels. PMID:25579972

  11. American Society of Nephrology Quiz and Questionnaire 2015: Electrolytes and Acid-Base Disorders.

    Rosner, Mitchell H; Perazella, Mark A; Choi, Michael J

    2016-04-01

    The Nephrology Quiz and Questionnaire remains an extremely popular session for attendees of the annual Kidney Week meeting of the American Society of Nephrology. During the 2015 meeting the conference hall was once again overflowing with eager quiz participants. Topics covered by the experts included electrolyte and acid-base disorders, glomerular disease, end-stage renal disease and dialysis, and kidney transplantation. Complex cases representing each of these categories together with single-best-answer questions were prepared and submitted by the panel of experts. Before the meeting, training program directors of nephrology fellowship programs and nephrology fellows in the United States answered the questions through an internet-based questionnaire. During the live session members of the audience tested their knowledge and judgment on the same series of case-oriented questions in a quiz. The audience compared their answers in real time using a cell-phone app containing the answers of the nephrology fellows and training program directors. The results of the online questionnaire were displayed, and then the quiz answers were discussed. As always, the audience, lecturers, and moderators enjoyed this highly educational session. This article recapitulates the session and reproduces selected content of educational value for theClinical Journal of the American Society of Nephrologyreaders. Enjoy the clinical cases and expert discussions. PMID:26825098

  12. Lipoamino acid-based micelles as promising delivery vehicles for monomeric amphotericin B.

    Serafim, Cláudia; Ferreira, Inês; Rijo, Patrícia; Pinheiro, Lídia; Faustino, Célia; Calado, António; Garcia-Rio, Luis

    2016-01-30

    Lipoamino acid-based micelles have been developed as delivery vehicles for the hydrophobic drug amphotericin B (AmB). The micellar solubilisation of AmB by a gemini lipoamino acid (LAA) derived from cysteine and its equimolar mixtures with the bile salts sodium cholate (NaC) and sodium deoxycholate (NaDC), as well as the aggregation sate of the drug in the micellar systems, was studied under biomimetic conditions (phosphate buffered-saline, pH 7.4) using UV-vis spectroscopy. Pure surfactant systems and equimolar mixtures were characterized by tensiometry and important parameters were determined, such as critical micelle concentration (CMC), surface tension at the CMC (γCMC), maximum surface excess concentration (Γmax), and minimum area occupied per molecule at the water/air interface (Amin). Rheological behaviour from viscosity measurements at different shear rates was also addressed. Solubilisation capacity was quantified in terms of molar solubilisation ratio (χ), micelle-water partition coefficient (KM) and Gibbs energy of solubilisation (ΔGs°). Formulations of AmB in micellar media were compared in terms of drug loading, encapsulation efficiency, aggregation state of AmB and in vitro antifungal activity against Candida albicans. The LAA-containing micellar systems solubilise AmB in its monomeric and less toxic form and exhibit in vitro antifungal activity comparable to that of the commercial formulation Fungizone. PMID:26617315

  13. First-principles study of physisorption of nucleic acid bases on small-diameter carbon nanotubes

    We report the results of our first-principles study based on density functional theory on the interaction of the nucleic acid base molecules adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U), with a single-walled carbon nanotube (CNT). Specifically, the focus is on the physisorption of base molecules on the outer wall of a (5, 0) metallic CNT possessing one of the smallest diameters possible. Compared to the case for CNTs with large diameters, the physisorption energy is found to be reduced in the high-curvature case. The base molecules exhibit significantly different interaction strengths and the calculated binding energies follow the hierarchy G>A>T>C>U, which appears to be independent of the tube curvature. The stabilizing factor in the interaction between the base molecule and CNT is dominated by the molecular polarizability that allows a weakly attractive dispersion force to be induced between them. The present study provides an improved understanding of the role of the base sequence in deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) in their interactions with carbon nanotubes of varying diameters

  14. New URJC-1 Material with Remarkable Stability and Acid-Base Catalytic Properties

    Pedro Leo

    2016-02-01

    Full Text Available Emerging new metal-organic structures with tunable physicochemical properties is an exciting research field for diverse applications. In this work, a novel metal-organic framework Cu(HIT(DMF0.5, named URJC-1, with a three-dimensional non-interpenetrated utp topological network, has been synthesized. This material exhibits a microporous structure with unsaturated copper centers and imidazole–tetrazole linkages that provide accessible Lewis acid/base sites. These features make URJC-1 an exceptional candidate for catalytic application in acid and base reactions of interest in fine chemistry. The URJC-1 material also displays a noteworthy thermal and chemical stability in different organic solvents of different polarity and boiling water. Its catalytic activity was evaluated in acid-catalyzed Friedel–Crafts acylation of anisole with acetyl chloride and base-catalyzed Knoevenagel condensation of benzaldehyde with malononitrile. In both cases, URJC-1 material showed very good performance, better than other metal organic frameworks and conventional catalysts. In addition, a remarkable structural stability was proven after several consecutive reaction cycles.

  15. High-molecular-weight polymers for protein crystallization: poly-γ-glutamic acid-based precipitants

    High-molecular-weight poly-γ-glutamic acid-based polymers have been synthesized, tested and adopted for protein crystallization. Protein crystallization has been revolutionized by the introduction of high-throughput technologies, which have led to a speeding up of the process while simultaneously reducing the amount of protein sample necessary. Nonetheless, the chemistry dimension of protein crystallization has remained relatively undeveloped. Most crystallization screens are based on the same set of precipitants. To address this shortcoming, the development of new protein precipitants based on poly-γ-glutamic acid (PGA) polymers with different molecular-weight ranges is reported here: PGA-LM (low molecular weight) of ∼400 kDa and PGA-HM (high molecular weight) of >1000 kDa. It is also demonstrated that protein precipitants can be expanded further to polymers with much higher molecular weight than those that are currently in use. Furthermore, the modification of PGA-like polymers by covalent attachments of glucosamine substantially improved their solubility without affecting their crystallization properties. Some preliminary PGA-based screens are presented here

  16. Oleic acid based heterolipid synthesis, characterization and application in self-microemulsifying drug delivery system.

    Kalhapure, Rahul S; Akamanchi, Krishnacharya G

    2012-04-01

    There is increasing demand for lipids owing to their use in formulating lipid based drug delivery systems of poorly soluble drugs. The present work discusses the synthesis, characterization of oleic acid based heterolipid and its use as oil in the development of self-microemulsifying drug delivery system (SMEDDS) for parenteral delivery. Synthesis was carried out by Michael addition of tert-butyl acrylate to 3-amino-1-propanol to obtain di-tert-butyl aminopropanol derivative. Reaction of this di-tert-butyl aminopropanol derivative with oleoyl chloride using p-dimethylaminopyridine as a coupling agent gave the desired heterolipid. It was characterized by (1)H NMR, (13)C NMR and MS to confirm the structure. It did not exhibit any measurable cytotoxicity, even up to 80μg/ml concentration. Application in parenteral drug delivery was explored using furosemide (FUR), a BCS class IV drug, as a model. FUR showed three times greater solubility in the heterolipid as compared to oleic acid. SMEDDSs were developed using heterolipid as oily phase, Solutol HS 15(®) as surfactant and ethanol as a co-surfactant. Developed SMEDDS could form spontaneous microemulsion on addition to various aqueous phases with mean globule size <70nm without any phase separation or drug precipitation even after 24h, and exhibited negligible hemolytic potential. PMID:22266534

  17. High-molecular-weight polymers for protein crystallization: poly-γ-glutamic acid-based precipitants

    Hu, Ting-Chou [Department of Chemistry, University of York, York YO10 5YW (United Kingdom); Korczyńska, Justyna [Department of Chemistry, University of York, York YO10 5YW (United Kingdom); Structural Biology Laboratory, University of York, York YO10 5YW (United Kingdom); Smith, David K. [Department of Chemistry, University of York, York YO10 5YW (United Kingdom); Brzozowski, Andrzej Marek, E-mail: marek@ysbl.york.ac.uk [Department of Chemistry, University of York, York YO10 5YW (United Kingdom); Structural Biology Laboratory, University of York, York YO10 5YW (United Kingdom)

    2008-09-01

    High-molecular-weight poly-γ-glutamic acid-based polymers have been synthesized, tested and adopted for protein crystallization. Protein crystallization has been revolutionized by the introduction of high-throughput technologies, which have led to a speeding up of the process while simultaneously reducing the amount of protein sample necessary. Nonetheless, the chemistry dimension of protein crystallization has remained relatively undeveloped. Most crystallization screens are based on the same set of precipitants. To address this shortcoming, the development of new protein precipitants based on poly-γ-glutamic acid (PGA) polymers with different molecular-weight ranges is reported here: PGA-LM (low molecular weight) of ∼400 kDa and PGA-HM (high molecular weight) of >1000 kDa. It is also demonstrated that protein precipitants can be expanded further to polymers with much higher molecular weight than those that are currently in use. Furthermore, the modification of PGA-like polymers by covalent attachments of glucosamine substantially improved their solubility without affecting their crystallization properties. Some preliminary PGA-based screens are presented here.

  18. Kidney injury, fluid, electrolyte and acid-base abnormalities in alcoholics

    Adebayo Adewale

    2014-01-01

    Full Text Available In the 21 st century, alcoholism and the consequences of ethyl alcohol abuse are major public health concerns in the United States, affecting approximately 14 million people. Pertinent to the global impact of alcoholism is the World Health Organisation estimate that 140 million people worldwide suffer from alcohol dependence. Alcoholism and alcohol abuse are the third leading causes of preventable death in the United States. Alcohol dependence and alcohol abuse cost the United State an estimated US$220 billion in 2005, eclipsing the expense associated with cancer (US$196 billion or obesity (US$133 billion. Orally ingested ethyl alcohol is absorbed rapidly without chemical change from the stomach and intestine, reaching maximum blood concentration in about an hour. Alcohol crosses capillary membranes by simple diffusion, affecting almost every organ system in the body by impacting a wide range of cellular functions. Alcohol causes metabolic derangements either directly, via its chemical by-product or secondarily through alcohol-induced disorders. Many of these alcohol-related metabolic disturbances are increased in severity by the malnutrition that is common in those with chronic alcoholism. This review focuses on the acute and chronic injurious consequences of alcohol ingestion on the kidney, as well as the fluid, electrolyte and acid-base abnormalities associated with acute and chronic ingestion of alcohol.

  19. Biodiesel Production from Spent Fish Frying Oil Through Acid-Base Catalyzed Transesterification

    Abdalrahman B. Fadhil

    2012-06-01

    Full Text Available Biodiesel fuels were prepared from a special type of frying oil namely spent fish frying oil through two step transesterification viz. acid-base catalyzed transesterification. Hydrochloric acid and potassium hydroxide with methanol were used for this purpose. The oil was pre-treated with (1.0 wt% HCl and methanol to reduce free fatty acids content of the oil. Then, conditions of the base catalyzed step such as base concentration, reaction temperature, methanol to oil molar ratio and reaction time were optimized. The study raveled that, 0.50% KOH w/w of oil; a 6:1 methanol to oil molar ratio; a reaction temperature of 60°C and a duration of 1h were the optimal conditions because they resulted in high biodiesel yield. Fuel properties of the products were assessed and found better than those of the parent oil. Furthermore, they met the specified limits according to the ASTM standards. Thin layer chromatography was used as a simple technique to monitor the transesterification of the oil. Blending of the optimal biodiesel sample with petro diesel using specified volume percentages was done as well. The results indicated that biodiesel had slight effect on the values of the assessed properties.

  20. Balance of multi-wavelets

    MAO Yibo

    2003-01-01

    The discrete scalar data need prefiltering when transformed by discrete multi-wavelet, but prefiltering will make some properties of multi-wavelets lost. Balanced multi-wavelets can avoid prefiltering. The sufficient and necessary condition of p-order balance for multi-wavelets in time domain, the interrelation between balance order and approximation order and the sampling property of balanced multi-wavelets are investigated. The algorithms of 1-0rder and 2-0rder balancing for multi-wavelets are obtained. The two algorithms both preserve the orthogonal relation between multi-scaling function and multi-wavelets. More importantly, balancing operation doesn't increase the length of filters, which suggests that a relatively short balanced multiwavelet can be constructed from an existing unbalanced multi-wavelet as short as possible.

  1. Negative leave balances

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1Â September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Â Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30Â September and/or 31Â December, leave will automatically be transferred from one account to another on the relevant dates i...

  2. Negative leave balances

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1 September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply.  Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30 September and/or 31 December, leave will automatically be transferred from one account to another on the relevant dates in or...

  3. C-3-symmetric, amino acid based organogelators and thickeners : a systematic study of structure-property relations

    de Loos, Maaike; van Esch, Jan H.; Kellogg, Richard M.; Feringa, Ben L.

    2007-01-01

    A class of C-3-symmetric amino acid based organogelators and thickeners featuring a rigid core have been developed. Structural variation yielded a number of compounds, the aggregation behaviour and resulting aggregates and gels of which were studied by FTIR spectroscopy, dropping ball measurements,

  4. Development and Evaluation of a Multimedia e-Learning Resource for Electrolyte and Acid-Base Disorders

    Davids, Mogamat Razeen; Chikte, Usuf M. E.; Halperin, Mitchell L.

    2011-01-01

    This article reports on the development and evaluation of a Web-based application that provides instruction and hands-on practice in managing electrolyte and acid-base disorders. Our teaching approach, which focuses on concepts rather than details, encourages quantitative analysis and a logical problem-solving approach. Identifying any dangers to…

  5. Correlation between the acid-base properties of the La2O3 catalyst and its methane reactivity.

    Chu, Changqing; Zhao, Yonghui; Li, Shenggang; Sun, Yuhan

    2016-06-28

    Density functional theory and coupled cluster theory calculations were carried out to study the effects of the acid-base properties of the La2O3 catalyst on its catalytic activity in the oxidative coupling of methane (OCM) reaction. The La(3+)-O(2-) pair site for CH4 activation is considered as a Lewis acid-Brönsted base pair. Using the Lewis acidity and the Brönsted basicity in the fluoride affinity and proton affinity scales as quantitative measures of the acid-base properties, the energy barrier for CH4 activation at the pair site can be linearly correlated with these acid-base properties. The pair site consisting of a strong Lewis acid La(3+) site and a strong Brönsted base O(2-) site is the most reactive for CH4 activation. In addition, the basicity of the La2O3 catalyst was traditionally measured by temperature-programmed desorption of CO2, but the CO2 chemisorption energy is better regarded as a combined measure of the acid-base properties of the pair site. A linear relationship of superior quality was found between the energy barrier for CH4 activation and the CO2 chemisorption energy, and the pair site favorable for CO2 chemisorption is also more reactive for CH4 activation, leading to the conflicting role of the "basicity" of the La2O3 catalyst in the OCM reaction. The necessity for very high reaction temperatures in the OCM reaction is rationalized by the requirement for the recovery of the most reactive acid-base pair site, which unfortunately also reacts most readily with the byproduct CO2 to form the very stable CO3(2-) species. PMID:27265027

  6. Kin Selection - Mutation Balance

    Dyken, J. David Van; Linksvayer, Timothy Arnold; Wade, Michael J.

    2011-01-01

    Abstract Social conflict, in the form of intraspecific selfish "cheating" has been observed in a number of natural systems. However, a formal, evolutionary genetic theory of social cheating that provides an explanatory, predictive framework for these observations is lacking. Here we derive the kin...... selection-mutation balance, which provides an evolutionary null hypothesis for the statics and dynamics of cheating. When social interactions have linear fitness effects and Hamilton´s rule is satisfied, selection is never strong enough to eliminate recurrent cheater mutants from a population, but cheater...... lineages are transient and do not invade. Instead, cheating lineages are eliminated by kin selection but are constantly reintroduced by mutation, maintaining a stable equilibrium frequency of cheaters. The presence of cheaters at equilibrium creates a "cheater load" that selects for mechanisms of cheater...

  7. Energy balance climate models

    North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

    1981-01-01

    An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved, and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

  8. A Balancing Act?

    Gerstlberger, Wolfgang; Knudsen, Mette Præst; Stampe, Ian

    efficiency moderates the effect of market attention on new product development. The paper therefore concludes that product innovation and energy efficiency is a balancing act, focusing on one will have detrimental effects on the other! These findings point to the conclusion that researchers and practitioners......With an undifferentiated catchword ‘eco-innovation’ is a largely understudied area, but of high relevance to the society and companies given the strong focus especially by governments on grand challenges like climate change, green technologies and environmental challenges. The paper utilizes the...... 2009 European Manufacturing Survey for the Danish sub-sample including 335 manufacturing firms. Through factor analysis, the paper confirms three main focus areas of new product development in relation to production facilities: efficiency considerations, market attention and greening of innovation...

  9. The balanced mind

    Allen, Micah; Smallwood, Jonathan; Christensen, Joanna;

    2013-01-01

    Self-generated thoughts unrelated to ongoing activities, also known as "mind-wandering," make up a substantial portion of our daily lives. Reports of such task-unrelated thoughts (TUTs) predict both poor performance on demanding cognitive tasks and blood-oxygen-level-dependent (BOLD) activity in......-wandering on response inhibition and monitoring, using the Error Awareness Task (EAT). We expected to replicate links between TUT and reduced inhibition, and explored whether variance in TUT would predict improved error monitoring, reflecting a capacity to balance between internal and external cognition. By...... during error awareness, supporting a link between monitoring and TUTs. Altogether our results suggest that although TUT is detrimental to task performance, fluctuations in attention between self-generated and external task-related thought is a characteristic of individuals with greater metacognitive...

  10. Balancing Trust and Control

    Jagd, Søren

    2010-01-01

    The purpose of this paper is to show that conceptualizing trust and control as interactively related processes, as opposed to more static conceptualizations of the two concepts and the relations between them, adds importantly towards understanding the challenges involved in balancing of trust and...... control in organizations. The paper examines recent literature on the conceptualization of the relation between trust and control in and between organizations. The literature review shows that trust and control has been conceptualized as either substituting or complementing each other. Further, it is...... found that the complementary/substitution debate calls for an explicit conceptualization of the relation between trust and control as an interactive process, in contrast to earlier conceptualizations of trust and control as two relatively static and isolated concepts. While the static perspective on...

  11. Gravity in the balance

    Although Einstein's theories of relativity showed that Newton's ideas about gravity, space and time were approximations, general relativity still predicts that the gravitational force between two point objects will obey an inverse-square law in the limit of low velocities and weak gravitational fields. Of course, we know that general relativity is probably an approximation as well and that some grander theory - possibly involving extra dimensions of space - will unify gravity with the other fundamental forces. Many of these theories predict that the inverse-square law will break down at distances that are becoming accessible to (relatively small) experiments with torsion balances. As researchers from the Eoet-Wash group in Seattle report 'Testing the gravitational inverse-square law', the inverse-square law has survived all tests so far, but its days are surely numbered. (U.K.)

  12. A Balancing Act?

    Gerstlberger, Wolfgang; Stampe, Ian; Knudsen, Mette Præst

    efficiency moderates the effect of market attention on new product development. The paper therefore concludes that product innovation and energy efficiency is a balancing act, focusing on one will have detrimental effects on the other! These findings point to the conclusion that researchers and practitioners....... Logistic regression analysis demonstrates that while market attention is important for new product development, green aspects of innovation and efficiency considerations for innovation are important for the energy efficiency of the production companies. Combining these models highlights that energy...... in innovation management have to take the specificities and interactions of different types of eco-innovation more carefully in consideration than so far and to formulate new managerial practices combining energy efficiency and product innovation....

  13. Amino acid-based surfactants – do they deserve more attention?

    Bordes, Romain; Holmberg, Krister

    2015-08-01

    The 20 standard amino acids (together with a few more that are not used in the biosynthesis of proteins) constitute a versatile tool box for synthesis of surfactants. Anionic, cationic and zwitterionic amphiphiles can be prepared and surfactants with several functional groups can be obtained by the proper choice of starting amino acid. This review gives examples of procedures used for preparation and discusses important physicochemical properties of the amphiphiles and how these can be taken advantage of for various applications. Micelles with a chiral surface can be obtained by self-assembly of enantiomerically pure surfactants and such supramolecular chirality can be utilized for asymmetric organic synthesis and for preparation of mesoporous materials with chiral pores. Surfactants based on amino acids with two carboxyl groups are effective chelating agents and can be used as collectors in mineral ore flotation. A surfactant based on cysteine readily oxidizes into the corresponding cystine compound, which can be regarded as a gemini surfactant. The facile and reversible cysteine-cystine transformation has been taken advantage of in the design of a switchable surfactant. A very attractive aspect of surfactants based on amino acids is that the polar head-group is entirely natural and that the linkage to the hydrophobic tail, which is often an ester or an amide bond, is easily cleaved. The rate of degradation can be tailored by the structure of the amphiphile. The ester linkage in betaine ester surfactants is particularly susceptible to alkaline hydrolysis and this surfactant type can be used as a biocide with short-lived action. This paper is not intended as a full review on the topic. Instead it highlights concepts that are unique to amino acid-based surfactants and that we believe can have practical implications. PMID:25846628

  14. Acid-base controllable recognition properties of a highly versatile calix[6]crypturea.

    Ménand, Mickaël; Jabin, Ivan

    2010-02-15

    Versatile concave receptors with binding properties that can be controlled by external stimuli are rare. Herein, we report on a calix[6]crypturea (1) that features two different binding sites in close proximity, that is, a tris(2-aminoethyl)amine (tren)-based tris-ureido cap that provides convergent hydrogen-bond-donor sites and a hydrophobic cavity suitable for the inclusion of organic guests. The binding properties of this heteroditopic receptor have been evaluated by NMR spectroscopic studies. Compound 1 behaves as a remarkably versatile host that strongly binds neutral molecules, anions, or contact ion pairs. Within each family of guests, compound 1 is able to discriminate between different guests with a high degree of selectivity. Indeed, neutral molecules that possess hydrogen-bond donor and acceptor groups, chloride anions, and linear ammonium ions associated to F(-) or Cl(-) are particularly well recognized. In comparison with all the related receptors, compound 1 displays several unique features: 1) charged or neutral species are also recognized in polar or protic solvents, 2) thanks to the flexibility of the calixarene structure, induced-fit processes allow the binding of large, biologically relevant ammonium salts such as neurotransmitters, and 3) the protonation of the basic cap leads to a positively charged receptor, 1.H(+), which is reluctant to host anions and in which host properties are now governed by strong charge-dipole interactions with the guests. In other words, compound 1 presents an acid-base controllable tris-ureido recognition site protected by a hydrophobic corridor that can select guests through induced-fit processes. Thus, its versatile host properties can be allosterically controlled by protonation and selective guest-switching processes are possible. To illustrate all these remarkable features, a sophisticated three-pole supramolecular switch, based on the interconversion of host-guest systems displaying either charged or neutral

  15. The application of hydrogen-palladium electrode for potentiometric acid-base determinations in tetrahydrofuran

    Jokić Anja B.

    2013-01-01

    Full Text Available The application of the hydrogen-palladium electrode (H2/Pd as the indicator electrode for the determination of relative acidity scale (Es, mV of tetrahydrofuran (THF and the potentiometric titrations of acids in this solvent was investigated. The relative acidity scale tetrahydrofuran was determined from the difference half-neutralization potentials of perchloric acid and tetrabutylammonium hydroxide (TBAH, which were measured by using both H2/Pd-SCE and glass-SCE electrode pairs. The experimentally obtained value of Es scale THF with a H2/Pd-SCE electrode pair was 1155 mV, and those obtained with glass-SCE electrode pair 880 mV. By using a H2/Pd indicator electrode, the individual acids (benzoic acid, palmitic acid, maleic acid, acetyl acetone, α-naphthol and two component acid mixtures (benzoic acid + α-naphthol, palmitic acid + α-naphthol, maleic acid + α-naphthol and maleic acid + ftalic acid were titrated with a standard solution of TBAH. In addition, sodium methylate and potassium hydroxide proved to be very suitable titrating agents for titrating of the individual acids and the acids in mixtures, respectively. The relative error of the determination of acids in mixture was less than 3%. The results are in agreement with those obtained by a conventional glass electrode. The advantages of H2/Pd electrode over a glass electrode in potentiometric acid-base determinations in tetrahydrofuran lie in the following: this electrode gives wider relative acidity scale THF, higher the potential jumps at the titration end-point and relatively fast response time; furthermore, it is very durable, simple to prepare and can be used in the titrations of small volumes. [Projekat Ministarstva nauke Republike Srbije, br.172051

  16. Variance approximation under balanced sampling

    Deville, Jean-Claude; Tillé, Yves

    2016-01-01

    A balanced sampling design has the interesting property that Horvitz–Thompson estimators of totals for a set of balancing variables are equal to the totals we want to estimate, therefore the variance of Horvitz–Thompson estimators of variables of interest are reduced in function of their correlations with the balancing variables. Since it is hard to derive an analytic expression for the joint inclusion probabilities, we derive a general approximation of variance based on a residual technique....

  17. Designing Multinational Electricity Balancing Markets

    Van der Veen, R.A.C.

    2012-01-01

    In today’s unbundled electricity markets, the balancing market is an intricate institutional arrangement that makes sure that the balance between electricity supply and demand is maintained. In the light of the development of a single electricity market in Europe, harmonization and integration of currently national balancing markets have received an increasing attention from governments, system operators, and regulators. This dissertation provides a systematic overview of the possibilities an...

  18. Psychology of the nuclear balance

    Sonntag, P.

    1981-10-01

    The balance of military forces is meant to prevent war. But it is a very precarious balance, which becomes all the more dubious when the deterrent is no longer psychologically effective: when the country attacked is deterred from striking back with nuclear weapons. A unilateral disarmament above the overkill level would be possible without endangering the balance. It would improve the climate for mutual disarmament.

  19. Radar channel balancing with commutation

    Doerry, Armin Walter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  20. Metabolic fate of poly-(lactic-co-glycolic acid-based curcumin nanoparticles following oral administration

    Harigae T

    2016-06-01

    Full Text Available Takahiro Harigae,1 Kiyotaka Nakagawa,1 Taiki Miyazawa,2 Nao Inoue,3 Fumiko Kimura,1 Ikuo Ikeda,3 Teruo Miyazawa4,5 1Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan; 2Vascular Biology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA; 3Laboratory of Food and Biomolecular Science, Graduate School of Agricultural Science, 4Food and Biotechnology Innovation Project, New Industry Creation Hatchery Center, 5Food and Health Science Research Unit, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan Purpose: Curcumin (CUR, the main polyphenol in turmeric, is poorly absorbed and rapidly metabolized following oral administration, which severely curtails its bioavailability. Poly-(lactic-co-glycolic acid-based CUR nanoparticles (CUR-NP have recently been suggested to improve CUR bioavailability, but this has not been fully verified. Specifically, no data are available about curcumin glucuronide (CURG, the major metabolite of CUR found in the plasma following oral administration of CUR-NP. Herein, we investigated the absorption and metabolism of CUR-NP and evaluated whether CUR-NP improves CUR bioavailability.Methods: Following oral administration of CUR-NP in rats, we analyzed the plasma and organ distribution of CUR and its metabolites using high-performance liquid chromatography-tandem mass spectrometry. To elucidate the mechanism of increased intestinal absorption of CUR-NP, we prepared mixed micelles comprised of phosphatidylcholine and bile salts and examined the micellar solubility of CUR-NP. Additionally, we investigated the cellular incorporation of the resultant micelles into differentiated Caco-2 human intestinal cells.Results: Following in vivo administration of CUR-NP, CUR was effectively absorbed and present mainly as CURG in the plasma which contained significant amounts of the metabolite compared with

  1. Spherical Nucleic Acids as Intracellular Agents for Nucleic Acid Based Therapeutics

    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

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

    Riffet, Vanessa; Frison, Gilles; Bouchoux, Guy

    2011-11-01

    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. PMID:21947236

  3. Metabolic fate of poly-(lactic-co-glycolic acid)-based curcumin nanoparticles following oral administration

    Harigae, Takahiro; Nakagawa, Kiyotaka; Miyazawa, Taiki; Inoue, Nao; Kimura, Fumiko; Ikeda, Ikuo; Miyazawa, Teruo

    2016-01-01

    Purpose Curcumin (CUR), the main polyphenol in turmeric, is poorly absorbed and rapidly metabolized following oral administration, which severely curtails its bioavailability. Poly-(lactic-co-glycolic acid)-based CUR nanoparticles (CUR-NP) have recently been suggested to improve CUR bioavailability, but this has not been fully verified. Specifically, no data are available about curcumin glucuronide (CURG), the major metabolite of CUR found in the plasma following oral administration of CUR-NP. Herein, we investigated the absorption and metabolism of CUR-NP and evaluated whether CUR-NP improves CUR bioavailability. Methods Following oral administration of CUR-NP in rats, we analyzed the plasma and organ distribution of CUR and its metabolites using high-performance liquid chromatography-tandem mass spectrometry. To elucidate the mechanism of increased intestinal absorption of CUR-NP, we prepared mixed micelles comprised of phosphatidylcholine and bile salts and examined the micellar solubility of CUR-NP. Additionally, we investigated the cellular incorporation of the resultant micelles into differentiated Caco-2 human intestinal cells. Results Following in vivo administration of CUR-NP, CUR was effectively absorbed and present mainly as CURG in the plasma which contained significant amounts of the metabolite compared with other organs. Thus, CUR-NP increased intestinal absorption of CUR rather than decreasing metabolic degradation and conversion to other metabolites. In vitro, CUR encapsulated in CUR-NP was solubilized in mixed micelles; however, whether the micelles contained CUR or CUR-NP had little influence on cellular uptake efficiency. Therefore, we suggest that the high solubilization capacity of CUR-NP in mixed micelles, rather than cellular uptake efficiency, explains the high intestinal absorption of CUR-NP in vivo. Conclusion These findings provide a better understanding of the bioavailability of CUR and CUR-NP following oral administration. To improve

  4. Paul Collier : Balancing beams

    2009-01-01

    As former head of AB Operations, Paul Collier and his group were in the ‘cockpit’ for the LHC’s maiden voyage - piloting the first beam around the ring. But now, as Head of the Beams Department, he will need his feet firmly on the ground in order to balance all the beam activities at CERN. "As Department Head, I’ll have less direct contact with the machines," Collier says with a hint of regret. "I’ll still obviously be very involved, but they won’t actually let me loose in front of the keyboard anymore!" As the new Head of the BE Department, Collier will be in charge of nearly 400 people, and will oversee all the beam activities, including the preparations for the longest period of beam operation in the history of CERN. In the new organization, the BE, TE and EN Departments have been grouped together in the Accelerator and Technology Sector. "‘Partnership’ is a key word for the three departments," says Collier. "The n...

  5. Interim balance: Ecology

    Subjects: The ecology problem - world wide. Sectoral balances: The examples of energy, transportation, chemistry, agriculture and food industry, water supply. Destruction of nature and human discord. Conservatives in our political parties and their views on environmental protection. Alliance between reds and 'greens', integration between reds and greens. The Rhine initiative. Lead respects no borders, experiences of citizens' action groups in Lothringia and the Saar district. International airport Munich-II/comments by a protestant. 'Give priority to life'/A hearing on environmental protection. 4:96 - 'greens' in the Bremen Senate. Policy in a hard-hearing world/psychology of citizens' action groups. Critical ecological research and scientific establishment. Full productivity and ecology. The deluge to follow/Hints on how to build an ark. Symbiosis is more than coexistence/Ecologists' social theory. Throwing in two hundred elementary particles/on the way to an ecological concept of science. Scientific journals. Alternative literature. Teaching model for a teaching subject 'ecology'. (orig.)

  6. Balancing safety and economics

    The safety requirements of NPPs have always aimed at limiting societal risks. This risk approach initially resulted in deterministic design criteria and concepts. In the 1980s the paradigm 'safety at all costs' arose and often led to questionable backfitting measures. Conflicts between new requirements, classical design concepts and operational demands were often ignored. The design requirements for advanced reactors ensure enhanced protection against severe accidents. Still, it is questionable whether the 'no-damage-outside-the-fence' criteria can be achieved deterministically and at competitive costs. Market deregulation and utility privatisation call for a balance between safety and costs, without jeopardising basic safety concepts. An ideal approach must be risk-based and imply modern PSAs and new methods for cost-benefit and ALARA analyses, embed nuclear risks in a wider risk spectrum, but also make benefits transparent within the context of a broader life experience. Governments should define basic requirements, minimum standards and consistent comparison criteria, and strengthen operator responsibility. Internationally sufficient and binding safety requirements must be established and nuclear technology transfer handled in a responsible way, while existing plants, with their continuous backfitting investments, should receive particular attention. (orig.)

  7. Par Pond water balance

    A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs

  8. Balancing "we" and "me".

    Congdon, Christine; Flynn, Donna; Redman, Melanie

    2014-10-01

    The open office is the dominant form of workspace design for good reason: It fosters collaboration, promotes learning, and nurtures strong culture. But what most companies fail to realize is that collaboration has a natural rhythm that requires both interaction and private contemplation. Companies have been trying for decades to find the balance between public and private workspace that best supports collaboration. In 1980 52% of U.S. employees lacked workspaces where they could concentrate without distraction. In response, high-walled cubicles took over the corporate landscape. By the late 1990s, the tide had turned, and only 23% of employees wanted more privacy, and 50% wanted more access to other people. Ever since, firms have been beefing up spaces that support collaboration and shrinking areas for individual work. But the pendulum seems to have swung too far: Once again, people feel a pressing need for privacy, not only to do heads-down work but to cope with the intensity of work today. To address these needs, according to the authors, we have to rethink our assumptions about privacy. Traditionally defined in physical terms, privacy is now about the individual's ability to control information and stimulation. In this article, the authors examine workspace design through the new lens of privacy and offer insights on how to foster teamwork and solitude. PMID:25509575

  9. The right balance

    CERN Bulletin

    2010-01-01

    Over the course of her career as a physicist, Felicitas Pauss, currently responsible for CERN's External Relations, has often been the sole woman in an environment dominated by men. While she freely admits that being a woman physicist can have as many advantages as disadvantages, she thinks the best strategy is to maintain the right balance.   From a very early age, Felicitas Pauss always wanted to be involved in projects that interested and fascinated her. That's how she came to study physics. When she was a first-year university student in Austria in 1970, it was still fairly uncommon for women to go into physics research. "I grew up in Salzburg with a background in music. At that time, it was certainly considered more ‘normal’ for a woman to study music than to do research in physics. But already in high school I was interested in physics and technical instruments and wanted to know how things work and what they are made of”. At the beginning of her care...

  10. Correlation of acid-base properties of substituted polystyrene-azo-pyrocatechol and characteristics of their chelates with zirconium

    Acid-base and complexing properties of new synthesized polymeric chelate-forming sorbents (PCS) - substituents of polystyrene-azo-pyrocatechol - are investigated and quantitative correlations between pKOH of functional analytical group (FAG) of sorbent and Hammet constants for para-substituent and ΔpKOH-ΔpK50 correlations of zirconium chelate-forming and pKOH-lgKstb (Kstb - constant of stability of PCS complexes with zirconium) of polychelates to study regularities of effect of peculiarities of structure and acid-base properties of FAG on parameters of zirconium chemical sorption. Established correlations make it possible to predict quantitative physicochemical parameters of sorbents and zirconium chemisorption process with the aim of directed synthesis and application of PCS in concentrating processes

  11. Acid-base properties and chemical composition of the surface of the InSb-ZnTe system

    The acid-base properties and chemical composition of the surface of solid solutions and binary components of the InSb-ZnTe system were studied by the hydrolytic adsorption, nonaqueous conductometric titration, mechanochemistry, IR spectroscopy, and mass spectrometry methods. The strength, nature, and concentration of acid centers were determined. Changes in the concentration of acid centers caused by surface exposure to CO and changes in the composition of the system were also studied. The mechanism of acid-base interactions was established. The chemical composition of the surface of system components exposed to air included adsorbed H2O molecules, OH- groups, hydrocarbon and oxo carbon compounds, and the products of surface atom oxidation. After thermal treatment in a vacuum, the composition of the surface approached the stoichiometric composition

  12. Optimal allocation in balanced sampling

    Tillé, Yves; Favre, Anne-Catherine

    2016-01-01

    The development of new sampling methods allows the selection of large balanced samples. In this paper we propose a method for computing optimal inclusion probabilities for balanced samples. Next, we show that the optimal Neyman allocation is a particular case of this method.

  13. A balancing act for renewables

    Elliott, David

    2016-01-01

    Energy storage will play a key role in increasing the use of variable energy sources. Nonetheless, storage is not the only balancing option and the overall design of power systems will incorporate a range of flexible generation, storage and grid-balancing options of different types and scales.

  14. H∞ Balancing for Nonlinear Systems

    Scherpen, Jacquelien M.A.

    1996-01-01

    In previously obtained balancing methods for nonlinear systems a past and a future energy function are used to bring the nonlinear system in balanced form. By considering a different pair of past and future energy functions that are related to the H∞ control problem for nonlinear systems we define H

  15. When Do States Balance Power?

    Hariri, Jacob Gerner; Wivel, Anders

    2010-01-01

    This paper explores the logic of balancing in structural realist theory. Arguably, the durability of the unipolar moment is a challenge to the logic of balancing. The paper uses the tools of microeconomics to build a mathematical model of structural realism. The simple model reiterates the...

  16. A clinical study to assess the effectiveness of a hyaluronic acid-based procedure for treatment of premature ejaculation

    Littara, A; Palmieri, B.; Rottigni, V; Iannitti, T

    2013-01-01

    Premature ejaculation is a sexual debilitating condition affecting a large number of men worldwide and leading to important dysfunctions influencing the patients' affective and emotional life. Hyaluronic acid is a natural and safe compound that has been widely used not only in the aesthetic medicine clinic, but also for treatment of osteoarthritis. The present study shows the effectiveness of a hyaluronic acid-based procedure for treatment of premature ejaculation. A hundred and ten male pati...

  17. Mechanical Behavior and Thermal Stability of Acid-Base Phosphate Cements and Composites Fabricated at Ambient Temperature

    Colorado, Henry A.

    2013-01-01

    This dissertation presents the study of the mechanical behavior and thermal stability of acid-base phosphate cements (PCs) and composites fabricated at ambient temperature. These materials are also known as chemically bonded phosphate ceramics (CBPCs). Among other advantages of using PCs when compared with traditional cements are the better mechanical properties (compressive and flexural strength), lower density, ultra-fast (controllable) setting time, controllable pH, and an environmentally ...

  18. A biochemical model for characterising the surface-active phospolipid bilayer of articular cartilage relative to acid-base equilibrium

    Z. Pawlak; J. Kotynska; Figaszewski, Z A; A. Gadomski; A. Gudaniec; A. Oloyede

    2008-01-01

    Purpose: This paper, addresses the question of how changes in acid - base equilibrium influence change in thecharge density of the phospholipid bilayer on articular cartilage surfaces during lubrication.Design/methodology/approach: Liposomes have been used to mimic biological phospholipid membranes onarticular cartilage surface where proteins are bounded, ions are transported, energy is transducted, and cellular processestake place. The charge density of the membrane was determined as a funct...

  19. Acid-base and copper-binding properties of three organic matter fractions isolated from a forest floor soil solution

    van Schaik, Joris W. J.; Kleja, Dan B.; Gustafsson, Jon Petter

    2010-01-01

    Vast amounts of knowledge about the proton- and metal-binding properties of dissolved organic matter (DOM) in natural waters have been obtained in studies on isolated humic and fulvic (hydrophobic) acids. Although macromolecular hydrophilic acids normally make up about one-third of DOM, their proton- and metal-binding properties are poorly known. Here, we investigated the acid-base and Cu-binding properties of the hydrophobic (fulvic) acid fraction and two hydrophilic fractions isolated from ...

  20. A different point of view: a continuous tracing of acid-base titration with fiber-optic sensor

    YALTKAYA, Şerafettin; KENDİR, Esra

    2013-01-01

    Our main aim was to investigate variations in the refractive index of a solution during chemical reaction. The variation of refractive index was measured through the entire acid--base titration process, especially near the equivalence point. To determine the equivalence point, the conductivity of the solution and the refractive index were measured simultaneously. In this preliminary study, sodium hydroxide and hydrochloric acid were used as the base and the acid solution, respective...

  1. Effect of intercalation of (HBO2)n and mechanochemical treatment on acid-base properties of kaolinite

    The effect of intercalation of (HBO2)n in kaolinite and mechanochemical treatment of mixtures of mineral with H3BO3 on acid-base properties of kaolinite surface was studied by potentiometric titration. It was found that intercalation of the mineral as well as mechanochemical treatment of the mixture depressed the acidity of the kaolinite surface, specifically at their combined effect. 8 refs., 1 fig., 1 tab

  2. Mixed acid-base disorders, hydroelectrolyte imbalance and lactate production in hypercapnic respiratory failure: the role of noninvasive ventilation.

    Claudio Terzano

    Full Text Available BACKGROUND: Hypercapnic Chronic Obstructive Pulmonary Disease (COPD exacerbation in patients with comorbidities and multidrug therapy is complicated by mixed acid-base, hydro-electrolyte and lactate disorders. Aim of this study was to determine the relationships of these disorders with the requirement for and duration of noninvasive ventilation (NIV when treating hypercapnic respiratory failure. METHODS: Sixty-seven consecutive patients who were hospitalized for hypercapnic COPD exacerbation had their clinical condition, respiratory function, blood chemistry, arterial blood gases, blood lactate and volemic state assessed. Heart and respiratory rates, pH, PaO(2 and PaCO(2 and blood lactate were checked at the 1st, 2nd, 6th and 24th hours after starting NIV. RESULTS: Nine patients were transferred to the intensive care unit. NIV was performed in 11/17 (64.7% mixed respiratory acidosis-metabolic alkalosis, 10/36 (27.8% respiratory acidosis and 3/5 (60% mixed respiratory-metabolic acidosis patients (p = 0.026, with durations of 45.1 ± 9.8, 36.2 ± 8.9 and 53.3 ± 4.1 hours, respectively (p = 0.016. The duration of ventilation was associated with higher blood lactate (p<0.001, lower pH (p = 0.016, lower serum sodium (p = 0.014 and lower chloride (p = 0.038. Hyponatremia without hypervolemic hypochloremia occurred in 11 respiratory acidosis patients. Hypovolemic hyponatremia with hypochloremia and hypokalemia occurred in 10 mixed respiratory acidosis-metabolic alkalosis patients, and euvolemic hypochloremia occurred in the other 7 patients with this mixed acid-base disorder. CONCLUSIONS: Mixed acid-base and lactate disorders during hypercapnic COPD exacerbations predict the need for and longer duration of NIV. The combination of mixed acid-base disorders and hydro-electrolyte disturbances should be further investigated.

  3. A biochemical model for characterising the surface-active phospolipid bilayer of articular cartilage relative to acid-base equilibrium

    Z. Pawlak

    2008-01-01

    Full Text Available Purpose: This paper, addresses the question of how changes in acid - base equilibrium influence change in thecharge density of the phospholipid bilayer on articular cartilage surfaces during lubrication.Design/methodology/approach: Liposomes have been used to mimic biological phospholipid membranes onarticular cartilage surface where proteins are bounded, ions are transported, energy is transducted, and cellular processestake place. The charge density of the membrane was determined as a function of pH and electrolyte concentration fromthe microelectrophoretic method. Liposome membrane was prepared as an aqueous solution of NaCl under variouspH conditions. Microelectrophoresis was used to examine the local acid-base equilibrium of the electrolytes with themembrane surface, which can be considered to model the phospholipids interface in articular cartilage.Findings: The adsorbed ions (H+, OH-, Na+, Cl- which are present in the electrically charged solutions of liposomemembrane comprising phosphatidycholine (PC, were found to exhibit pH-responsive quasi-periodic behavior.Research limitations/implications: We have established that the acid-base dissociation behavior inphospholipid bilayers of articular cartilage is a key to understanding biolubrication processes. For example,previous investigators found that the formation of the multilayer of polyisopeptide/hyaluronic acid depends onsurface properties such as film thickness, surface friction, surface wetability; wetness and swelling behavior.Future work should consider the adsorption of polyelectrolyte ions, e.g., the glycoprotein lubricin and hyaluronan,on the liposome membrane surface in the presence of H+ and OH- ions.Originality/value: A novel model of the joints’ phospholipid bilayers has been created using liposome membraneThis model can be applied in the investigation of polyelectrolyte ions such as lubricin, in articular cartilage. Wehave demonstrated that the acid-base processes on

  4. Investigation of thermal and viscoelastic properties of polymers relevant to hot melt extrusion - III: Polymethacrylates and polymethacrylic acid based polymers.

    Tapan Parikh; Simerdeep Singh Gupta; Anuprabha Meena; Serajuddin, Abu T. M.

    2014-01-01

    Polymers are a major part of final medicinal drug products prepared by hot melt extrusion (HME). Therefore it is necessary to understand their behavior when subjected to heat and mechanical stresses during the development of the HME processes. The aim of this work was to generate a database of the physicochemical properties for polymethacrylates and polymethacrylic acid based polymers relevant to HME. All six polymers tested were amorphous and had < 2% moisture. In differential scanning calo...

  5. Recent developments in nucleic acid based techniques for use in rumen manipulation

    Christopher McSweeney

    2009-07-01

    Full Text Available Nucleic acid-based techniques which can be used to characterise complex microbial communities without incubation are now being employed regularly in ruminant nutrition studies. Conventional culture-based methods for enumerating rumen microorganisms (bacteria, archaea, protozoa, and fungi have been superseded and are now used mainly to obtain pure isolates of novel organisms and reference strains that are required for the development and validation of the nucleic acid approaches. These reference strains are also essential for physiological studies of the lifestyle of the organisms as well as sources of genomic DNA and RNA that can be analysed for functional gene activity. The foundation of the molecular ecology techniques is 16S/18S rDNA sequence analysis which has provided a phylogenetically based classification scheme for enumeration and identification of microbial community members. The use of this marker gene in assays involving the use of single nucleic acid probes or primer sets is rapidly evolving to high throughput approaches such as microarray analysis and new generation sequencing technologies. While these analyses are very informative for determining the composition of the microbial community and monitoring changes in population size, they can only infer function based on these observations. The focus of nucleic acid research is now shifting to the functional analysis of the ecosystem which involves the measurement of functional genes and their expression in the predominant or specific members of the rumen microbial community. Functional gene studies are less developed than 16S rDNA-based analysis of community structure. Also for gene expression studies there are inherent problems involved in extracting high quality RNA from digesta, and priming cDNA synthesis from bacterial mRNA. This paper reviews nucleic acid based molecular methods which have recently been developed for studying the structure and function of rumen microbial

  6. Data needs for nutrient balances

    Vinther, Finn Pilgaard

    One of the tools for evaluating the results of environmental action plans or EU directives related to nutrients in the agricultural sector is to follow the development of annually estimated nitrogen (N) and phosphorus (P) balances and surplus. Unlike greenhouse gas and ammonia emissions, countries...... are not required to report N and P balances for agriculture as part of any international conventions. As a consequence, there is no organisation equivalent to the Intergovernmental Panel on Climate Change (IPCC) or United Nations Economic Commission for Europe (UNECE) who has responsibility for...... standardising and improving the methodology to calculate such balances. However, Eurostat and OECD have jointly established a standard for using a gross N balances, and the soil N balance calculated by the CAPRI model has gained acceptance in European policymaking. It can be mentioned that the Task Force on...

  7. Gallic acid-based indanone derivative interacts synergistically with tetracycline by inhibiting efflux pump in multidrug resistant E. coli.

    Dwivedi, Gaurav Raj; Tiwari, Nimisha; Singh, Aastha; Kumar, Akhil; Roy, Sudeep; Negi, Arvind Singh; Pal, Anirban; Chanda, Debabrata; Sharma, Ashok; Darokar, Mahendra P

    2016-03-01

    The purpose of the present study was to study the synergy potential of gallic acid-based derivatives in combination with conventional antibiotics using multidrug resistant cultures of Escherichia coli. Gallic acid-based derivatives significantly reduced the MIC of tetracycline against multidrug resistant clinical isolate of E. coli. The best representative, 3-(3',4,'5'-trimethoxyphenyl)-4,5,6-trimethoxyindanone-1, an indanone derivative of gallic acid, was observed to inhibit ethidium bromide efflux and ATPase which was also supported by in silico docking. This derivative extended the post-antibiotic effect and decreased the mutation prevention concentration of tetracycline. This derivative in combination with TET was able to reduce the concentration of TNFα up to 18-fold in Swiss albino mice. This derivative was nontoxic and well tolerated up to 300 mg/kg dose in subacute oral toxicity study in mice. This is the first report of gallic acid-based indanone derivative as drug resistance reversal agent acting through ATP-dependent efflux pump inhibition. PMID:26658982

  8. Lewis Acid-Base Adduct Approach for High Efficiency Perovskite Solar Cells.

    Lee, Jin-Wook; Kim, Hui-Seon; Park, Nam-Gyu

    2016-02-16

    Since the first report on the long-term durable 9.7% solid-state perovskite solar cell employing methylammonium lead iodide (CH3NH3PbI3), mesoporous TiO2, and 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-MeOTAD) in 2012, following the seed technologies on perovskite-sensitized liquid junction solar cells in 2009 and 2011, a surge of interest has been focused on perovskite solar cells due to superb photovoltaic performance and extremely facile fabrication processes. The power conversion efficiency (PCE) of perovskite solar cells reached 21% in a very short period of time. Such an unprecedentedly high photovoltaic performance is due to the intrinsic optoelectronic property of organolead iodide perovskite material. Moreover, a high dielectric constant, sub-millimeter scale carrier diffusion length, an underlying ferroelectric property, and ion migration behavior can make organolead halide perovskites suitable for multifunctionality. Thus, besides solar cell applications, perovskite material has recently been applied to a variety fields of materials science such as photodetectors, light emitting diodes, lasing, X-ray imaging, resistive memory, and water splitting. Regardless of application areas, the growth of a well-defined perovskite layer with high crystallinity is essential for effective utilization of its excellent physicochemical properties. Therefore, an effective methodology for preparation of high quality perovskite layers is required. In this Account, an effective methodology for production of high quality perovskite layers is described, which is the Lewis acid-base adduct approach. In the solution process to form the perovskite layer, the key chemicals of CH3NH3I (or HC(NH2)2I) and PbI2 are used by dissolving them in polar aprotic solvents. Since polar aprotic solvents bear oxygen, sulfur, or nitrogen, they can act as a Lewis base. In addition, the main group compound PbI2 is known to be a Lewis acid. Thus, PbI2 has a chance

  9. How Our Balance System Works

    ... from your eyes, the inner ear, and the sensory systems of the body (such as the skin, muscles, ... function? How are vision, the inner ear, and sensory systems impacting functional balance? Some of the tests of ...

  10. Cautions Concerning Electronic Analytical Balances.

    Johnson, Bruce B.; Wells, John D.

    1986-01-01

    Cautions chemists to be wary of ferromagnetic samples (especially magnetized samples), stray electromagnetic radiation, dusty environments, and changing weather conditions. These and other conditions may alter readings obtained from electronic analytical balances. (JN)

  11. Skylab water balance error analysis

    Leonard, J. I.

    1977-01-01

    Estimates of the precision of the net water balance were obtained for the entire Skylab preflight and inflight phases as well as for the first two weeks of flight. Quantitative estimates of both total sampling errors and instrumentation errors were obtained. It was shown that measurement error is minimal in comparison to biological variability and little can be gained from improvement in analytical accuracy. In addition, a propagation of error analysis demonstrated that total water balance error could be accounted for almost entirely by the errors associated with body mass changes. Errors due to interaction between terms in the water balance equation (covariances) represented less than 10% of the total error. Overall, the analysis provides evidence that daily measurements of body water changes obtained from the indirect balance technique are reasonable, precise, and relaible. The method is not biased toward net retention or loss.

  12. An Oscillating Magnet Watt Balance

    Ahmedov, H

    2015-01-01

    We establish the principles for a new generation of simplified and accurate watt balances in which an oscillating magnet generates Faraday's voltage in a stationary coil. A force measuring system and a mechanism providing vertical movements of the magnet are completely independent in an oscillating magnet watt balance. This remarkable feature allows to establish the link between the Planck constant and a macroscopic mass by a one single experiment. Weak dependence on variations of environmental and experimental conditions, weak sensitivity to ground vibrations and temperature changes, simple force measuring procedure, small sizes and other useful features offered by the novel approach considerably reduce the complexity of the experimental setup. We formulate the oscillating magnet watt balance principle and establish the measurement procedure for the Planck constant. We discuss the nature of oscillating magnet watt balance uncertainties and give a brief description of the National Metrology Institute (UME) wa...

  13. Laboratory Workhorse: The Analytical Balance.

    Clark, Douglas W.

    1979-01-01

    This report explains the importance of various analytical balances in the water or wastewater laboratory. Stressed is the proper procedure for utilizing the equipment as well as the mechanics involved in its operation. (CS)

  14. Hatha yoga on body balance

    Erick Tadeu Prado; Vagner Raso; Renata Coelho Scharlach; Cristiane Akemi Kasse

    2014-01-01

    Background: A good body balance requires a proper function of vestibular, visual, and somatosensory systems which can be reach with exercise practice and/or yoga. Aim: To determine the effects of a 5-month hatha yoga training program on body balance in young adults. Materials and Methods: This study used a controlled, nonrandomized design, where the experimental group underwent a 5-month training program and were then compared with the control group that had a sedentary lifestyle. A c...

  15. Risk, Balanced Skills and Entrepreneurship

    Hsieh, C.; Parker, S.C.; Praag, van, B.

    2011-01-01

    This paper proposes that risk aversion encourages individuals to invest in balanced skill profiles, making them more likely to become entrepreneurs. By not having taken this possible linkage into account, previous research has underestimated the impacts both of risk aversion and balanced skills on the likelihood individuals choose entrepreneurship. Data on Dutch university graduates provides evidence which supports this contention. It thereby raises the possibility that even risk-averse peopl...

  16. Balancing local budgets in Romania

    Attila GYÖRGY

    2014-01-01

    Local budgets in Romania are balanced with revenues transferred from state budget according to the criterions laid down in the Local Public Finance Act. These criterions are focusing on the financial capacity, population and surface, each local budget getting balancing amounts inversely with the administrative unit’s wellness and directly to size. The repartition algorithm is used for more than a decade, but periodically it was revised in order to be better folded to fiscal policy and economi...

  17. Electric power balance sheet 2012

    The mission of RTE, the French electricity Transportation grid, a public service assignment, is to balance the electricity supply and demand in real time. This report presents RTE's technical results for the year 2012: strong seasonal contrast of power consumption, rise of the renewable energies contribution in meeting the electricity demand, slight decay of the nuclear and thermal power generation, decrease of the export balance and change in trades structure, adaptation of RTE's network to the evolutions of the energy system

  18. Financial intermediary balance sheet management

    Adrian,Tobias; Shin, Hyun Song

    2011-01-01

    Conventional discussions of balance sheet management by nonfinancial firms take the set of positive net present value (NPV) projects as given, which in turn determines the size of the assets of the firm. The focus is on the composition of equity and debt in funding such assets. In contrast, the balance sheet management of financial intermediaries reveals that it is equity that behaves like the predetermined variable, and the asset size of the bank or financial intermediary is determined by th...

  19. VALUE BALANCE IN CONSUMER PROTECTION

    Dahsan Hasan

    2015-01-01

    This research aims to describe how the realization of ' Balance ' in the Consumer Protection Act, describes how the responsibility of the parties (consumers, businessmen and the Government) so that it can realize the value of the balance in the protection of consumer, Research conducted in the framework of the preparation of this dissertation is to type the socio-juridical, in addition to researching the secondary legal materials in the form of legal regulations, manual and electronic law lib...

  20. Balancer effects in opinion dynamics

    Cheon, Taksu

    2016-01-01

    We introduce a novel type of contrarian agent, the balancer, to Galam model of opinion dynamics, in order to account for the skepticism over one-sidedness and for the sense of fairness. We find that the inclusion of balancers along with floaters and inflexibles brings about a critical point on parametric plane of the dynamical system, which results in the new kind of stable final states of the opinion dynamics, that seem to capture several intriguing features found often in mature democracies.

  1. Assessment of perioperative fluid balance

    Bumbaširević V.; Marković D.; Vlajković G.; Sinđelić R.

    2009-01-01

    Careful assessment of the fluid balance is required in the perioperative period since appropriate fluid therapy is essential for successful patient's outcome. Haemodynamic monitoring allows understanding the physiology of the circulation and changes of fluid balance in the perioperative period. This is diagnostic aid and guide for fluid replacement therapy. Patient's volume status is frequently assessed by different haemodynamic variables that could be targeted as the endpoints for fluid ther...

  2. Form 6 - gas balancing agreement

    In 1988, a special Committee of the Rocky Mountain Mineral Law Foundation undertook a project to draft a model from gas balancing agreement. This project was initiated at the request of a number of Foundation members who felt that a model form gas balancing agreement would facilitate the negotiation of operating agreement, since gas balancing issues had become sticking points in the process. The Committee was composed of attorneys representing a wide cross-section of the oil and gas industry including both major and independent oil companies, production companies with interstate pipeline affiliates, and private practitioners. The Committee attempted to address the more controversial issues in gas balancing with optional provisions in the Form. To facilitate the negotiation process, the number of optional provisions was minimized. This form may be used as an Appendix to the new A.A.P.L. Form 610-1989 Model Form Operating Agreement. This book includes provision of this Form which are: Ownership of gas production; Balancing of production accounts; Cash balancing upon depletion; Deliverability tests; Nominations; Statements; Payment of taxes; Operating expenses; Overproducing allowable; Payment of leasehold burdens; Operator's liability; Successors and assigns; Audits; Arbitration; and Operator's fees

  3. Exercise training of late-pregnant and nonpregnant dairy cows affects physical fitness and acid-base homeostasis.

    Davidson, J A; Beede, D K

    2009-02-01

    The objective was to determine if exercise training improves physical fitness of nonlactating, late-pregnant and nonpregnant multiparous Holstein cows and alters acid-base homeostasis during an exercise test on a treadmill. Twenty-six pairs (each pair having 1 late-pregnant and 1 nonpregnant) of cows were assigned to treatments of exercise training or no exercise. Exercise training was walking (1.25 to 1.5 h at 3.25 km/h) every other day in an outdoor mechanical walker for 70 d. Cows completed treadmill exercise tests on d 0, 30, and 60 of the experiment or about d 70, 40, and 10 before expected parturition of the pregnant cow of each pair. On d 0, physical fitness was similar among all cows based on durations of treadmill tests, heart rates, and acid-base measurements at given workloads (21.1 +/- 0.6 min; 144 +/- 2.2 beats per min; plasma lactate 3.1 +/- 1.9 mmol/L; and venous blood pH 7.44 +/- 0.0035, respectively). After 60 d of training, exercised cows walked longer during treadmill exercise tests compared with nonexercised cows (23.7 vs. 18.3 +/- 0.85 min, respectively), indicating greater physical fitness (pooled across pregnancy status). Heart rates and plasma lactate concentrations at given workloads were less (144 vs. 156 +/- 2.7 beats per min; and 1.4 vs. 3.2 +/- 0.24 mmol/L for exercised compared with nonexercised cows, respectively). Additionally, exercised cows more effectively maintained acid-base homeostasis during treadmill tests compared with nonexercised cows. Metabolic, endocrine, and nutritional demands associated with late pregnancy did not affect responses differently to exercise training for late-pregnant compared with nonpregnant cows. Overall, exercise training of late-pregnant and nonpregnant cows for 60 d improved physical fitness. PMID:19164665

  4. Single Sodium Pyruvate Ingestion Modifies Blood Acid-Base Status and Post-Exercise Lactate Concentration in Humans

    Robert A. Olek

    2014-05-01

    Full Text Available This study examined the effect of a single sodium pyruvate ingestion on a blood acid-base status and exercise metabolism markers. Nine active, but non-specifically trained, male subjects participated in the double-blind, placebo-controlled, crossover study. One hour prior to the exercise, subjects ingested either 0.1 g·kg−1 of body mass of a sodium pyruvate or placebo. The capillary blood samples were obtained at rest, 60 min after ingestion, and then three and 15 min after completing the workout protocol to analyze acid-base status and lactate, pyruvate, alanine, glucose concentrations. The pulmonary gas exchange, minute ventilation and the heart rate were measured during the exercise at a constant power output, corresponding to ~90% O2max. The blood pH, bicarbonate and the base excess were significantly higher after sodium pyruvate ingestion than in the placebo trial. The blood lactate concentration was not different after the ingestion, but the post-exercise was significantly higher in the pyruvate trial (12.9 ± 0.9 mM than in the placebo trial (10.6 ± 0.3 mM, p < 0.05 and remained elevated (nonsignificant after 15 min of recovery. The blood pyruvate, alanine and glucose concentrations, as well as the overall pulmonary gas exchange during the exercise were not affected by the pyruvate ingestion. In conclusion, the sodium pyruvate ingestion one hour before workout modified the blood acid-base status and the lactate production during the exercise.

  5. Yarrowia lipolytica as an oleaginous cell factory platform for the production of fatty acid-based biofuel and bioproducts

    Ali eAbghari

    2014-06-01

    Full Text Available Today’s biotechnologists seek new biocatalysts to meet the growing demand for the bioproducts. This review critically evaluates the potential use of Y. lipolytica as an oleaginous cell factory platform. This yeast has undergone extensive modifications for converting a wide range of hydrophobic and hydrophilic biomass, including alkane, oil, glycerol and sugars to fatty acid-based products. This article highlights challenges in the development of this platform and provides an overview of strategies to enhance its potential in the sustainable production of biodiesel, functional dietary lipid compounds and other value-added oleochemical compounds. Future applications of the recombinant Y. lipolytica platform are also discussed.

  6. An exploratory study into students' conceptual understanding of acid/base principles associated with chemical buffer systems

    MacGowan, Catherine Elizabeth

    The overall objective of this research project was to provide an insight into students' conceptual understanding of acid/base principles as it relates to the comprehension and correct application of scientific concepts during a problem-solving activity. The difficulties experienced learning science and in developing appropriate problem-solving strategies most likely are predetermined by students' existing conceptual and procedural knowledge constructs; with the assimilation of newly acquired knowledge hindering or aiding the learning process. Learning chemistry requires a restructuring of content knowledge which will allow the individual to assemble and to integrate his/her own perception of science with instructional knowledge. The epistemology of constructivism, the theoretical grounding for this research project, recognizes the student's role as an active participant in the learning process. The study's design was exploratory in nature and descriptive in design. The problem-solving activity, the preparation of a chemical buffer solution at pH of 9, was selected and modified to reflect and meet the study's objective. Qualitative research methods (i.e., think aloud protocols, retrospective interviews, survey questionnaires such as the Scale of Intellectual Development (SID), and archival data sources) were used in the collection and assessment of data. Given its constructivist grounding, simplicity, and interpretative view of knowledge acquisition and learning of collegiate aged individuals, the Perry Intellectual and Ethical Development Model (1970) was chosen as the applied model for evaluation student cognition. The study's participants were twelve traditional college age students from a small, private liberal arts college. All participants volunteered for the project and had completed or were completing a general college chemistry course at the time of the project. Upon analysis of the data the following observations and results were noted: (1) students

  7. Effect of modification with scandium oxide on the hydroxyl coating and acid-base properties of the zirconium dioxide surface

    Physicochemical properties of Sc2O3 - ZrO2 system surface were studied by the method of IR spectroscopy, surface properties of the samples prepared by coprecipitation and by impregnation method were compared. Influence of scandium oxide concentration as a modifying component on hydroxylic coating and acid-base properties of zirconium dioxide surface was ascertained. It is shown that zirconium dioxide modification by scandium does not give rise to the appearance of new types of Lewis acid centers. Modifying effect of scandium was compared to that of yttrium and lanthanum

  8. VALUE BALANCE IN CONSUMER PROTECTION

    Dahsan Hasan

    2015-07-01

    Full Text Available This research aims to describe how the realization of ' Balance ' in the Consumer Protection Act, describes how the responsibility of the parties (consumers, businessmen and the Government so that it can realize the value of the balance in the protection of consumer, Research conducted in the framework of the preparation of this dissertation is to type the socio-juridical, in addition to researching the secondary legal materials in the form of legal regulations, manual and electronic law library, relevant research results in the field of law of particular problems in the field of consumer protection and other written materials, as well as researching various legal facts about consumer protection which occur in the field as well as its impact on the general public. The results showed that: 1 a form of value balance in consumer protection legislation lies in the synergy between the rights and obligations the rights and obligations of consumers, businessmen, as well as the duties and responsibilities of the Government, the supporters of both public institutions and private consumers are dispute resolution Efforts, and the use of contract oversight of overall indicators are assessed if merged between the assessment of consumers and businessmen, as well as assessment of the Government then obtained 32 indicators of where the total number of indicators corresponding to the value of the balance of a total of 10 indicators, while the total number of which is not in accordance with the value of the balance as much as 21 indicators and only one indicator that his judgment balanced. So that the efforts made in the framework of the fulfilment of the rights and obligations of consumers and businessmen as well as maximize the task and responsibility of the Government is still having a lot of obstacles or not be able to realize the value of balance

  9. Separate Determination of Borohydride, Borate, Hydroxide, and Carbonate in the Borohydride Fuel Cell by Acid-Base and Iodometric Potentiometric Titration

    Churikov, A. V.; S. L. Shmakov; Romanova, V. O.; Zapsis, K. V.; Ushakov, A. V.; Ivanishchev, A. V.; Churikov, M. A.

    2014-01-01

    A methodology for quantitative chemical analysis of the complex “borohydride-borate-hydroxide-carbonate-water” mixtures used as fuel in the borohydride fuel cell was developed and optimized. The methodology includes the combined usage of the acid-base and iodometric titration methods. The acid-base titration method, which simultaneously uses the technique of differentiation and computer simulation of titration curves, allows one to determine the contents of hydroxide (alkali), carbonate, and ...

  10. Balancing act: the ultimate balance nutrition consulting center.

    Engle, L

    1998-11-01

    Nutritional issues often complicate health care but are very important in HIV treatment where diet can play a strong role in drug absorption and effectiveness. A Canadian company has started a for-fee nutritional counseling service called Ultimate Balance. The nutritionists at Ultimate Balance require medical disclosure and extensive telephone interviews with patients, and also review patients' cases and medications. The nutritional guidance provided is controversial, because it is funded by a company that produces nutritional supplements, and counselors sometimes recommend those supplements. A personal experience with the nutritional counseling service is described. Contact information is provided. PMID:11365979

  11. Acid base status in swamp buffaloes (Bubalus Bubalis fed rice straw and concentrate with addition of sodium

    G Joseph

    2001-12-01

    Full Text Available An experiment was conducted to study the addition of NaHCO3 and Na2CO3 on acid-base status in swamp buffaloes, Three fistulated buffaloes were each introduced to dietary treatment control diett (50% rice straw + 50% concentrate, control + \\0% NaHCO3 and diet control + 10% Na2CO3 in two times Latin Square Design. The diets contained 9,7% crude protein and 53% TDN to achieve maintenance requirements of the animals. Parameters measured include (l Fed consumption, water consumption and urine volume. (2 pH in rumen fluid, saliva, bLood and urine, (3 natrium mineral content in rumen fluid, saliva, blood and urine. The results of the experiment showed higher pH in the rumen fluid, saliva, blood and urine of buffaloes due to supplementation of NaHCO3 and Na2CO3, Water consumption and urine volume was significanly increased as the effect of Na supplement. The acid-base status of buffaloes was apparently normal in all animals.

  12. Studies of Modification of Zeolite by Tandem Acid-Base Treatments and its Adsorptions Performance Towards Thorium

    G. Nurliati

    2015-08-01

    Full Text Available Hierarchical zeolite was prepared from natural zeolite using tandem acid-base treatments and applied as adsorbent for Th(IV removal. Natural zeolite occurred naturally as microporous material. It was modified using two familiar methods simultaneously, dealumination and desilication techniques, to change its micropore size into hierarchical pores.. Extensive characterization of both natural and modified zeolites were conducted using XRD, BET, SEM-EDS, and AAS. XRD Patterns of raw, pre-treated , and acid-base tandem modified zeolites show that the modification process has not changed the crystal properties of this material. However, the Si/Al ratio is increased from 6.688 to 11.401 for Na-zeolite (NaZ and modified zeolite, ZA2B respectively. The surface area is increased from 125.4 m2/g (NaZ to 216.8 m2/g (ZA2B, indicative of the creation of mesopore in addition to naturally micropore structure. The application of these zeolite materials as adsorbent were carried out using solution of 50 ppm Th4+measured using UV-Vis spectrophotometer. The UV-Vis result shows that the modified zeolite (ca. 10 mg has higher adsorption capacity than natural zeolite. The adsorption process does not fit into Langmuir and Freundlich isotherm and the adsorption capacity of this material increase from 909 mg/g to 2000 mg/g for NaZ and ZA2B respectively.

  13. Vanadium oxides supported on hydrotalcite-type precursors: the effect of acid base properties on the oxidation of isopropanol

    Vanadium oxide supported on hydrotalcite-type precursors was studied in the oxidation of isopropanol. Hydrotalcites with different y = Mg/Al ratios were synthesized by the method of coprecipitation nitrates of Mg and Al cations with K2CO3 as precipitant. The decomposition of these hydrotalcite precursors at 450 deg C yielded homogeneous MgyAlOx mixed oxides that contain the Al+3 cations totally incorporated into the MgO framework. The materials were characterized by chemical analysis, BET superficial area, X-ray diffraction, temperature-programmed reduction (TPR) and the reaction of isopropanol, a probe molecule used to evaluate the acid-base properties. The results of TPR showed that the reducibility of V+5 decreased with the increase in magnesium loading in catalysts. The X-ray diffraction patterns of Al-rich hydrotalcite precursors showed the presence of crystalline phases of brucite and gibbsite. It was shown that chemical composition, texture, acid-base properties of the active sites and also Mg/Al ratio strongly affect the formation of the products in the oxidation of isopropanol. The Al-rich catalysts were much more active than the Mg-rich ones, converting isopropanol mainly to propylene. (author)

  14. Vanadium oxides supported on hydrotalcite-type precursors: the effect of acid-base properties on the oxidation of isopropanol

    D. M. Meira

    2006-09-01

    Full Text Available Vanadium oxide supported on hydrotalcite-type precursors was studied in the oxidation of isopropanol. Hydrotalcites with different y = Mg/Al ratios were synthesized by the method of coprecipitation nitrates of Mg and Al cations with K2CO3 as precipitant. The decomposition of these hydrotalcite precursors at 450°C yielded homogeneous MgyAlOx mixed oxides that contain the Al+3 cations totally incorporated into the MgO framework. The materials were characterized by chemical analysis, BET superficial area, X-ray diffraction, temperature-programmed reduction (TPR and the reaction of isopropanol, a probe molecule used to evaluate the acid-base properties. The results of TPR showed that the reducibility of V+5 decreased with the increase in magnesium loading in catalysts. The X-ray diffraction patterns of Al-rich hydrotalcite precursors showed the presence of crystalline phases of brucite and gibbsite. It was shown that chemical composition, texture, acid-base properties of the active sites and also Mg/Al ratio strongly affect the formation of the products in the oxidation of isopropanol. The Al-rich catalysts were much more active than the Mg-rich ones, converting isopropanol mainly to propylene.

  15. Acid-base equilibrium in aqueous solutions of 1,3-dimethylbarbituric acid as studied by 13C NMR spectroscopy

    Gryff-Keller, A.; Kraska-Dziadecka, A.

    2011-12-01

    13C NMR spectra of 1,3-dimethylbarbituric acid in aqueous solutions of various acidities and for various solute concentrations have been recorded and interpreted. The spectra recorded at pH = 2 and below contain the signals of the neutral solute molecule exclusively, while the ones recorded at pH = 7 and above only the signals of the appropriate anion, which has been confirmed by theoretical GIAO-DFT calculations. The signals in the spectra recorded for solutions of pH acid-base equilibrium. The kinetic data determined this way have been used to clarify the mechanisms of these processes. The numerical analysis has shown that under the investigated conditions deprotonation of the neutral solute molecules undergoes not only via a simple transfer of the C-H proton to water molecules but also through a process with participation of the barbiturate anions. Moreover, the importance of tautomerism, or association, or both these phenomena for the kinetics of the acid-base transformations in the investigated system has been shown. Qualitatively similar changes of 13C NMR spectra with the solution pH variation have been observed for the parent barbituric acid.

  16. Chemical composition and acid-base properties of the surface of GaAs-CdS solid solutions

    Chemical composition and acid-base properties of the surfaces of GaAs-CdS solid solutions and the constituent binary compounds exposed to air, vacuum, CO, and NH3 were analyzed using mass spectrometry, IR spectrometry, isoelectric-point pH (pHiso) analysis, and mechanochemical methods. Powders and films were prepared from the solid solutions by isothermal diffusion and discrete vacuum evaporation, respectively. XRD and Raman analysis revealed that a solid solution has a sphalerite or wurtzite structure, depending on its composition. The initial surface of all the systems studied exhibited acidic properties: the pH value ranged from 4.9 to 6.45. The surfaces contained Lewis (electron accepting) and Bronsted (adsorbed H2O and CO2 molecules, OH- groups) sites. The acidity of the surface increased upon treatment with CO and decreased upon treatment with NH3. For all types of treatment, the concentration dependence of the acid-base properties of the surface exhibited an extremum. The strongest acidic sites were revealed on the surface of the (GaAs)0.95 (CdS)0.05 solid solution. The adsorption activity of this solution, a promising material for manufacturing gas sensors, was evaluated

  17. Dentin bonding performance using Weibull statistics and evaluation of acid-base resistant zone formation of recently introduced adhesives.

    Guan, Rui; Takagaki, Tomohiro; Matsui, Naoko; Sato, Takaaki; Burrow, Michael F; Palamara, Joseph; Nikaido, Toru; Tagami, Junji

    2016-07-30

    Dentin bonding durability of recently introduced dental adhesives: Clearfil SE Bond 2 (SE2), Optibond XTR (XTR), and Scotchbond Universal (SBU) was investigated using Weibull analysis as well as analysis of the micromorphological features of the acid-base resistant zone (ABRZ) created for the adhesives. The bonding procedures of SBU were divided into three subgroups: self-etch (SBS), phosphoric acid (PA) etching on moist (SBM) or dry dentin (SBD). All groups were thermocycled for 0, 5,000 and 10,000 cycles followed by microtensile bond strength testing. Acid-base challenge was undertaken before SEM and TEM observations of the adhesive interface. The etch-and-rinse method with SBU (SBM and SBD) created inferior interfaces on the dentin surface which resulted in reduced bond durability. ABRZ formation was detected with the self-etch adhesive systems; SE2, XTR and SBS. In the PA etching protocols of SBM and SBD, a thick hybrid layer but no ABRZ was detected, which might affect dentin bond durability. PMID:27335136

  18. Dairy Proteins and Energy Balance

    Bendtsen, Line Quist

    High protein diets affect energy balance beneficially through decreased hunger, enhanced satiety and increased energy expenditure. Dairy products are a major source of protein. Dairy proteins are comprised of two classes, casein (80%) and whey proteins (20%), which are both of high quality, but...... casein is absorbed slowly and whey is absorbed rapidly. The present PhD study investigated the effects of total dairy proteins, whey, and casein, on energy balance and the mechanisms behind any differences in the effects of the specific proteins. The results do not support the hypothesis that dairy...... proteins, whey or casein are more beneficial than other protein sources in the regulation of energy balance, and suggest that dairy proteins, whey or casein seem to play only a minor role, if any, in the prevention and treatment of obesity....

  19. Constrained Allocation Flux Balance Analysis

    Mori, Matteo; Martin, Olivier C; De Martino, Andrea; Marinari, Enzo

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferr...

  20. Efficacy of virtual reality-based balance training versus the Biodex balance system training on the body balance of adults

    Ibrahim, Manal S.; Mattar, Ayman G.; Elhafez, Salam M.

    2016-01-01

    [Purpose] This study investigated efficacy of virtual reality (VR)-based balance training on enhancing balance and postural reactions of adults as a low-cost new modality compared to the established Biodex Balance System (BBS). [Subjects] Thirty normal adults of both genders were divided randomly into two equal-sized experimental groups of 15: BBS balance training and VR balance training. [Methods] The training programmes were conducted in 12 sessions, three 15-min sessions per week. The Nint...

  1. Balanced dynamics in the Tropics

    Verkley, W.T.M.; Velde, van der, G.

    2010-01-01

    For the shallow-water equations on an equatorial beta plane, the properties of low-frequency Rossby waves and (mixed) Rossby-gravity waves are investigated. It is shown that in the low-frequency limit the horizontal divergence of these solutions is zero and their geopotential satisfies = f, where f = y is the Coriolis parameter and is the stream function of the non-divergent velocity field. This type of balance is rather different from the geostrophic balance satisfied by Kelvin waves. It can...

  2. Heider balance in human networks

    Gawroński, P.; Kułakowski, K.

    2005-07-01

    Recently, a continuous dynamics was proposed to simulate dynamics of interpersonal relations in a society represented by a fully connected graph. The final state of such a society was found to be identical with the so-called Heider balance (HB), where the society is divided into two mutually hostile groups. In the continuous model, a polarization of opinions was found in HB. Here we demonstrate that the polarization occurs also in Barabási-Albert networks, where the Heider balance is not necessarily present. In the second part of this work we demonstrate the results of our formalism, when applied to reference examples: the Southern women and the Zachary club.

  3. The social balance sheet 2005

    Ph. Delhez; P. Heuse

    2006-01-01

    Each year, the National Bank examines the provisional results of the social balance sheets of Belgian enterprises. As the social balance sheets are not yet all available for 2005, the study is based on a limited population of enterprises, compiled according to the principle of a constant sample. This population is made up of 48,976 enterprises employing around 4,441,000 workers in 2005. The main results of the analysis are as follows. As an average, employment increased by 0.5 p.c. between 20...

  4. The relevance of clinical balance assessment tools to differentiate balance deficits

    Mancini, Martina; Horak, Fay B.

    2010-01-01

    Control of balance is complex and involves maintaining postures, facilitating movement, and recovering equilibrium. Balance control consists of controlling the body center of mass over its limits of stability. Clinical balance assessment can help assess fall risk and/or determine the underlying reasons for balance disorders. Most functional balance assessment scales assess fall risk and the need for balance rehabilitation but do not differentiate types of balance deficits. A system approach t...

  5. An Improved Hadoop Data Load Balancing Algorithm

    Kun Liu

    2013-12-01

    Full Text Available Data load balancing is one of the key problems of big data technology. As a big data application, Hadoop has had many successful applications. HDFS is Hadoop Distributed File System and has the load balancing procedure which can balance the storage load on each machine. However, this method cannot balance the overload rack preferentially, and so it is likely to cause the breakdown of overload machines. In this paper, we focus on the overload machines and propose an improved algorithm for balancing the overload racks preferentially. The improved method constructs Prior Balance List list which includes overload machines, For Balance List list and NextForBalanceList list by many factors and balances among the racks selected from these lists firstly. Experiments show that the improved method can balance the overload racks in time and reduce the possibility of breakdown of these racks

  6. Balancing Covariates via Propensity Score Weighting

    Li, Fan; Morgan, Kari Lock; Zaslavsky, Alan M.

    2014-01-01

    Covariate balance is crucial for an unconfounded descriptive or causal comparison. However, lack of balance is common in observational studies. This article considers weighting strategies for balancing covariates. We define a general class of weights-the balancing weights-that balance the weighted distributions of the covariates between treatment groups. These weights incorporate the propensity score to weight each group to an analyst-selected target population. This class unifies existing we...

  7. Balance Systems and the Variational Bicomplex

    Serge Preston

    2011-01-01

    In this work we show that the systems of balance equations (balance systems) of continuum thermodynamics occupy a natural place in the variational bicomplex formalism. We apply the vertical homotopy decomposition to get a local splitting (in a convenient domain) of a general balance system as the sum of a Lagrangian part and a complemental ''pure non-Lagrangian'' balance system. In the case when derivatives of the dynamical fields do not enter the constitutive relations of the balance system,...

  8. Energy balance invariance for interacting particle systems

    Yavari, Arash; Marsden, Jerrold E.

    2009-01-01

    This paper studies the principle of invariance of balance of energy and its consequences for a system of interacting particles under groups of transformations. Balance of energy and its invariance is first examined in Euclidean space. Unlike the case of continuous media, it is shown that conservation and balance laws do not follow from the assumption of invariance of balance of energy under time-dependent isometries of the ambient space. However, the postulate of invariance of balance of ener...

  9. A Balanced Higher Education System

    Brown, Roger

    2011-01-01

    This article explores what is meant by "a balanced higher education system". It argues that the Clarkian "triangle of coordination" (Clark, 1983) and the more recent model of Martinez and Richardson (2003) should be replaced by one that distinguishes between "self" and "collective" interests in both the academy and the wider society. Such a scheme…

  10. Balance Scorecard in Hospital Units

    Pu?an Alina; Ivan Oana Raluca

    2014-01-01

    Balance Scorecard (BSC) is a tool for measuring the performance, used mainly in the private sector. Social and economic changes of recent years have given rise to a number of objective needs, particularly in the management of “public money”.

  11. Learning from Balance Sheet Visualization

    Tanlamai, Uthai; Soongswang, Oranuj

    2011-01-01

    This exploratory study examines alternative visuals and their effect on the level of learning of balance sheet users. Executive and regular classes of graduate students majoring in information technology in business were asked to evaluate the extent of acceptance and enhanced capability of these alternative visuals toward their learning…

  12. Finding Balance in the Winds.

    Wilbur, Michael

    1999-01-01

    Describes the author's experience of and reflections concerning a group workshop facilitated by Michael Tlanusta Garrett of the Eastern Band of Cherokee. Provides information about the Native American teachings and traditions of the four winds, balance, and harmony, and discusses the use of self by group leaders as a powerful therapeutic and…

  13. [Assessment of perioperative fluid balance].

    Sindelić, R; Vlajković, G; Marković, D; Bumbasirević, V

    2009-01-01

    Careful assessment of the fluid balance is required in the perioperative period since appropriate fluid therapy is essential for successful patient's outcome. Haemodynamic monitoring allows understanding the physiology of the circulation and changes of fluid balance in the perioperative period. This is diagnostic aid and guide for fluid replacement therapy. Patient's volume status is frequently assessed by different haemodynamic variables that could be targeted as the endpoints for fluid therapy and resuscitation. Fluid balance is the crucial factor in the maintenance of haemodynamic stability, tissue oxygenation and organ function. When the haemodynamic monitoring is applied in a rigorous and consistent manner, it reduces mortality and length of stay as well as costs incurred. There are a number of tests which describe the effectiveness of the invasive haemodynamic monitoring procedures usage. Since the pulmonary artery catheter (PAC) had been introduced into clinical practice it was considered as a golden standard for cardiac output measurements, haemodynamic and fluid balance assessment. Nevertheless, in previous 10 years new minimally invasive and noninvasive simple techniques for haemodynamic monitoring and patient's hydroelectricity status evaluation have been developed. They can replace PAC under different clinical circumstances and some of these techniques PMID:19504992

  14. The effect of acid-base clustering and ions on the growth of atmospheric nano-particles

    Lehtipalo, Katrianne; Rondo, Linda; Kontkanen, Jenni; Schobesberger, Siegfried; Jokinen, Tuija; Sarnela, Nina; Kürten, Andreas; Ehrhart, Sebastian; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Sipilä, Mikko; Yli-Juuti, Taina; Duplissy, Jonathan; Adamov, Alexey; Ahlm, Lars; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Downard, Andrew J.; Dunne, Eimear M.; Flagan, Richard C.; Guida, Roberto; Hakala, Jani; Hansel, Armin; Jud, Werner; Kangasluoma, Juha; Kerminen, Veli-Matti; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Kupiainen-Määttä, Oona; Laaksonen, Ari; Lawler, Michael J.; Leiminger, Markus; Mathot, Serge; Olenius, Tinja; Ortega, Ismael K.; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud; Rissanen, Matti P.; Ruuskanen, Taina; Santos, Filipe D.; Schallhart, Simon; Schnitzhofer, Ralf; Simon, Mario; Smith, James N.; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Tomé, António; Vaattovaara, Petri; Vehkamäki, Hanna; Vrtala, Aron E.; Wagner, Paul E.; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M.; Virtanen, Annele; Donahue, Neil M.; Carslaw, Kenneth S.; Baltensperger, Urs; Riipinen, Ilona; Curtius, Joachim; Worsnop, Douglas R.; Kulmala, Markku

    2016-05-01

    The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.

  15. Acid-base equilibrium during capnoretroperitoneoscopic nephrectomy in patients with end-stage renal failure: a preliminary report.

    Demian, A D; Esmail, O M; Atallah, M M

    2000-04-01

    We have studied the acid-base equilibrium in 12 patients with end-stage renal failure (ESRF) during capnoretroperitoneoscopic nephrectomy. Bupivacaine (12 mL, 0.375%) and morphine (2mg) were given in the lumbar epidural space, and fentanyl (0.5 microg kg(-1)) and midazolam (50 microg kg(-1)) were given intravenously. Anaesthesia was induced by thiopental, maintained with halothane carried by oxygen enriched air (inspired oxygen fraction = 0.35), and ventilation was achieved with a tidal volume of 10 mL kg(-1) at a rate of 12 min(-1). This procedure resulted in a mild degree of respiratory acidosis that was cleared within 60 min. We conclude that capnoretroperitoneoscopic nephrectomy can be performed in patients with end-stage renal failure with minimal transient respiratory acidosis that can be avoided by increased ventilation. PMID:10866009

  16. The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions

    Liao, Jiahn-Haur; Wu, Tzu-Hua; Chen, Ming-Yi; Chen, Wei-Ting; Lu, Shou-Yun; Wang, Yi-Hsuan; Wang, Shao-Pin; Hsu, Yen-Min; Huang, Yi-Shiang; Huang, Zih-You; Lin, Yu-Ching; Chang, Ching-Ming; Huang, Fu-Yung; Wu, Shih-Hsiung

    2015-12-01

    In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO32- and DCCM/SeO32- complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation.

  17. Small-Nucleic-Acid-Based Therapeutic Strategy Targeting the Transcription Factors Regulating the Vascular Inflammation, Remodeling and Fibrosis in Atherosclerosis

    Sung Won Youn

    2015-05-01

    Full Text Available Atherosclerosis arises when injury to the arterial wall induces an inflammatory cascade that is sustained by a complex network of cytokines, together with accumulation of lipids and fibrous material. Inflammatory cascades involve leukocyte adherence and chemotaxis, which are coordinated by the local secretion of adhesion molecules, chemotactic factors, and cytokines. Transcription factors are critical to the integration of the various steps of the cascade response to mediators of vascular injury, and are induced in a stimulus-dependent and cell-type-specific manner. Several small-nucleic-acid-based therapeutic strategies have recently been developed to target transcription factors: antisense oligodeoxynucleotides, RNA interference, microRNA, and decoy oligodeoxynucleotides. The aim of this review was to provide an overview of these particular targeted therapeutic strategies, toward regulation of the vascular inflammation, remodeling and fibrosis associated with atherosclerosis.

  18. Physisorption of Nucleic Acid Bases on Boron Nitride Nanotubes: A new class of Hybrid Nano-Bio Materials

    Mukhopadhyay, Saikat; Scheicher, Ralph H; Pandey, Ravindra; Karna, Shashi P

    2009-01-01

    We investigate the adsorption of the nucleic acid bases, adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U) on the outer wall of a high curvature semiconducting single-walled boron nitride nanotube (BNNT) by first principles density functional theory calculations. The calculated binding energy shows the order: G>A~C~T~U implying that the interaction strength of the (high-curvature) BNNT with the nucleobases, G being an exception, is nearly the same. A higher binding energy for the G-BNNT conjugate appears to result from a stronger hybridization of the molecular orbitals of G and BNNT, since the charge transfer involved in the physisorption process is insignificant. A smaller energy gap predicted for the G-BNNT conjugate relative to that of the pristine BNNT may be useful in application of this class of biofunctional materials to the design of the next generation sensing devices.

  19. Physisorption of Nucleic Acid Bases on Boron Nitride Nanotubes: A new class of Hybrid Nano-Bio Materials

    Mukhopadhyay, Saikat; Gowtham, S.; Scheicher, Ralph; Pandey, Ravindra; Karna, Shashi

    2010-03-01

    We investigate the adsorption of the nucleic acid bases, adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U) on the outer wall of a high curvature semiconducting single-walled boron nitride nanotube (BNNT) by first principles density functional theory calculations. The calculated binding energy shows the order: G>A C T U implying that the interaction strength of the (high-curvature) BNNT with the nucleobases, G being an exception, is nearly the same. A higher binding energy for the G-BNNT conjugate appears to result from a stronger hybridization of the molecular orbitals of G and BNNT, since the charge transfer involved in the physisorption process is insignificant. A smaller energy gap predicted for the G-BNNT conjugate relative to that of the pristine BNNT may be useful in application of this class of biofunctional materials to the design of the next generation sensing devices.

  20. The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions

    Liao, Jiahn-Haur; Wu, Tzu-Hua; Chen, Ming-Yi; Chen, Wei-Ting; Lu, Shou-Yun; Wang, Yi-Hsuan; Wang, Shao-Pin; Hsu, Yen-Min; Huang, Yi-Shiang; Huang, Zih-You; Lin, Yu-Ching; Chang, Ching-Ming; Huang, Fu-Yung; Wu, Shih-Hsiung

    2015-01-01

    In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO32− and DCCM/SeO32− complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation. PMID:26635113

  1. Fabrication of Amino Acid Based Silver Nanocomposite Hydrogels from PVA-Poly(Acrylamide-co-Acryloyl phenylalanine) and Their Antimicrobial Studies

    Cha, Hyeongrae; Babu, V. Ramesh; Rao, K. S. V. Krishna; Kim, Yonghyun; Mei, Surong; Lee, Yongill; Joo, Woo Hong [Changwon National Univ., Changwon (Korea, Republic of)

    2012-10-15

    New silver nanoparticle (AgNP)-loaded amino acid based hydrogels were synthesized successfully from poly (vinyl alcohol) (PVA) and poly(acryl amide-co-acryloyl phenyl alanine) (PAA) by redox polymerization. The formation of AgNP in hydrogels was confirmed by using a UV-Vis spectrophotometer and XRD. The structure and morphology of silver nanocomposite hydrogels were studied by using a scanning electron microscopy (SEM), which demonstrated scattered nanoparticles, ca. 10-20 nm. Thermogravimetric analysis revealed large differences of weight loss (i. e., 48%) between the prestine hydrogel and silver nanocomposite. The antibacterial studies of AgNP-loaded PAA (Ag-PAA) hydrogels was evaluated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. These Ag-PAA hydrogels showed significant activities against all the test bacteria. Newly developed hydrogels could be used for medical applications, such as artificial burn dressings.

  2. Development of an optimized hyaluronic acid-based lipidic nanoemulsion co-encapsulating two polyphenols for nose to brain delivery.

    Nasr, Maha

    2016-05-01

    The development of mucoadhesive lipidic nanoemulsion based on hyaluronic acid, co-encapsulating two polyphenols (resveratrol and curcumin) for the transnasal treatment of neurodegenerative diseases was attempted in the current manuscript. Nanoemulsions were prepared by the spontaneous emulsification method, and were characterized for their particle size, zeta potential, mucoadhesive strength and morphology. The selected formula was tested for its antioxidant potential, in vitro and ex vivo release of the two polyphenols, safety on nasal mucosa and in vivo quantification of the two drugs in rat brains. Its stability was tested by monitoring the change in particle size, zeta potential, drugs' content and antioxidant potential upon storage for 3 months. The optimized hyaluronic acid based nanoemulsion formula displayed a particle size of 115.2 ± 0.15 and a zeta potential of -23.9 ± 1.7. The formula displayed a spherical morphology and significantly higher mucoadhesive strength compared to its non mucoadhesive counterpart. In addition, the nanoemulsion was able to preserve the antioxidant ability of the two polyphenols and protect them from degradation. Diffusion controlled release of the two drugs was achievable till 6 hours, with an ex vivo flux across sheep nasal mucosa of 2.86 and 2.09 µg/cm(2)hr for resveratrol and curcumin, respectively. Moreover, the mucoadhesive nanoemulsion was safe on nasal mucosa and managed to increase the amounts of the two polypehnols in the brain (about 7 and 9 folds increase in AUC0-7 h for resveratrol and curcumin, respectively). Hyaluronic acid based lipidic nanoemulsion proved itself as a successful carrier enhancing the solubility, stability and brain targetability of polyphenols. PMID:26401600

  3. Acid/base bifunctional carbonaceous nanomaterial with large surface area: Preparation, characterization, and adsorption properties for cationic and anionic compounds

    Nanostructured carbonaceous materials are extremely important in the nano field, yet developing simple, mild, and “green” methods that can make such materials possess large surface area and rich functional groups on their surfaces still remains a considerable challenge. Herein, a one-pot and environment-friendly method, i.e., thermal treatment (180 °C; 18 h) of water mixed with glucose and chitosan (CTS), has been proposed. The resultant carbonaceous nanomaterials were characterized by field emitting scanning electron microscope, N2 adsorption/desorption, Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, and zeta-potential analysis. It was found that, in contrast to the conventional hydrothermally carbonized product from pure glucose, with low surface area (9.3 m2 g−1) and pore volume (0.016 cm3 g−1), the CTS-added carbonaceous products showed satisfactory textural parameters (surface area and pore volume up to 254 m2 g−1 and 0.701 cm3 g−1, respectively). Moreover, it was also interestingly found that these CTS-added carbonaceous products possessed both acidic (–COOH) and basic (–NH2) groups on their surfaces. Taking the advantages of large surface area and –COOH/–NH2 bifunctional surface, the carbonaceous nanomaterials exhibited excellent performance for adsorptions of cationic compound (i.e., methylene blue) at pH 10 and anionic compound (i.e., acid red 18) at pH 2, respectively. This work not only provides a simple and green route to prepare acid/base bifunctional carbonaceous nanomaterials with large surface area but also well demonstrates their potential for application in adsorption. - Highlights: • A simple and green method was proposed to prepare carbon nanomaterials. • The carbon product showed acid/base bifunctional surface with large surface area. • The carbon material could efficiently adsorb both cationic and anionic compounds

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

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

    2016-06-21

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

  5. Effects of humic acid-based buffer + cation on chemical characteristics of saline soils and maize growth

    W. Mindari

    2014-10-01

    Full Text Available Humic acid is believed to maintain the stability of the soil reaction, adsorption / fixation / chelate of cation, thereby increasing the availability of water and plant nutrients. On the other hand, the dynamics of saline soil cation is strongly influenced by the change of seasons that disrupt water and plant nutrients uptake. This experiment was aimed to examine the characteristics of the humic acid from compost, coal, and peat and its function in the adsorption of K+ and NH4+ cations, thus increasing the availability of nutrients and of maize growth. Eighteen treatments consisted of three humic acid sources (compost, peat and coal, two cation additives (K+ and NH4+, and three doses of humic acid-based buffer (10, 20, and 30 g / 3kg, were arranged in a factorial completely randomized with three replicates. The treatments were evaluated against changes in pH, electric conductivity (EC, cation exchange capacity (CEC, chlorophyll content, plant dry weight and plant height. The results showed that the addition of K+ and NH4+ affected pH, CEC, K+, NH4+, and water content of the buffer. Application of humic acid-based buffer significantly decreased soil pH from > 7 to about 6.3, decreased soil EC to 0.9 mS / cm, and increased exchangeable Na from 0.40 to 0.56 me / 100g soil, Ca from 15.57 to 20.21 me/100 g soil, Mg from 1.76 to 6.52 me/100 g soil, and K from 0.05-0.51 me / 100g soil. Plant growth (plant height, chlorophyll content, leaf area, and stem weight at 35 days after planting increased with increasing dose of humic acid. The dose of 2.0g peat humic acid + NH4+ / 3 kg of soil or 30g peat humic acid + K+ / 3 kg of oil gave the best results of maize growth.

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

    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. PMID:23796109

  7. Embryonic common snapping turtles (Chelydra serpentina) preferentially regulate intracellular tissue pH during acid-base challenges.

    Shartau, Ryan B; Crossley, Dane A; Kohl, Zachary F; Brauner, Colin J

    2016-07-01

    The nests of embryonic turtles naturally experience elevated CO2 (hypercarbia), which leads to increased blood PCO2  and a respiratory acidosis, resulting in reduced blood pH [extracellular pH (pHe)]. Some fishes preferentially regulate tissue pH [intracellular pH (pHi)] against changes in pHe; this has been proposed to be associated with exceptional CO2 tolerance and has never been identified in amniotes. As embryonic turtles may be CO2 tolerant based on nesting strategy, we hypothesized that they preferentially regulate pHi, conferring tolerance to severe acute acid-base challenges. This hypothesis was tested by investigating pH regulation in common snapping turtles (Chelydra serpentina) reared in normoxia then exposed to hypercarbia (13 kPa PCO2 ) for 1 h at three developmental ages: 70% and 90% of incubation, and yearlings. Hypercarbia reduced pHe but not pHi, at all developmental ages. At 70% of incubation, pHe was depressed by 0.324 pH units while pHi of brain, white muscle and lung increased; heart, liver and kidney pHi remained unchanged. At 90% of incubation, pHe was depressed by 0.352 pH units but heart pHi increased with no change in pHi of other tissues. Yearlings exhibited a pHe reduction of 0.235 pH units but had no changes in pHi of any tissues. The results indicate common snapping turtles preferentially regulate pHi during development, but the degree of response is reduced throughout development. This is the first time preferential pHi regulation has been identified in an amniote. These findings may provide insight into the evolution of acid-base homeostasis during development of amniotes, and vertebrates in general. PMID:27091863

  8. 26 CFR 1.167(b)-2 - Declining balance method.

    2010-04-01

    ... balance Jan. 1 Acquisitions Current retirements Asset balance Dec. 31 Average balance Avg. reserve before... Acquisition Asset balance Dec. 31 Avg. balance Reserve Dec. 31, before depreciation Net depreciable...

  9. LOAD BALANCING WITH NEURAL NETWORK

    Nada M. Al Sallami

    2013-11-01

    Full Text Available This paper discusses a proposed load balance technique based on artificial neural network. It distributes workload equally across all the nodes by using back propagation learning algorithm to train feed forward Artificial Neural Network (ANN. The proposed technique is simple and it can work efficiently when effective training sets are used. ANN predicts the demand and thus allocates resources according to that demand. Thus, it always maintains the active servers according to current demand, which results in low energy consumption than the conservative approach of over-provisioning. Furthermore, high utilization of server results in more power consumption, server running at higher utilization can process more workload with similar power usage. Finally the existing load balancing techniques in cloud computing are discussed and compared with the proposed technique based on various parameters like performance, scalability, associated overhead... etc. In addition energy consumption and carbon emission perspective are also considered to satisfy green computing.

  10. Universally Balanced Combinatorial Optimization Games

    Xiaotie Deng

    2010-09-01

    Full Text Available This article surveys studies on universally balanced properties of cooperative games defined in a succinct form. In particular, we focus on combinatorial optimization games in which the values to coalitions are defined through linear optimization programs, possibly combinatorial, that is subject to integer constraints. In economic settings, the integer requirement reflects some forms of indivisibility. We are interested in the classes of games that guarantee a non-empty core no matter what are the admissible values assigned to the parameters defining these programs. We call such classes universally balanced. We present characterization and complexity results on the universally balancedness property for some classes of interesting combinatorial optimization games. In particular, we focus on the algorithmic properties for identifying universally balancedness for the games under discussion.

  11. Double-yoke balanced compressor

    A double-yoke balanced compressor for a cryogenic cooler that has only linear motion imparted to balanced piston and cylinder masses. A piston yoke is driven in the linear stroke direction by a piston axially offset crankshaft cam and a cylinder yoke is driven linearly by a cylinder axially offset crankshaft cam that is exactly offset 1800 from the other cam. A large circular bushing in the compressor housing covers the entire outer cylinder head during linear operation to prevent blow by and to guide the cylinder linearly. The lower portion of the piston and cylinder connecting rods fit into linear guides that are further comprised of low molecular weight gas filled cavities to provide additional air bearing smoothness to the linear motion of the piston and cylinder

  12. Energy balance in coronal funnels

    Rabin, Douglas

    1991-01-01

    The energy balance in magnetic flux tubes is examined semianalytically for the case in which thermal conduction balances radiation or in which enthalpy transport occurs. Different values are considered for areal constriction, shape, length, and maximum temperature. The overall energy budget of the solar corona is not significantly affected by magnetic constriction. A bowl-shaped funnel with a constriction factor of 4 describes the empirical differential-emission measure for log-T values between approximately 5.3 and 6.0. Loop-scaling relationships are derived for the full range of models to illustrate the dependence of the constant of proportionality on the properties of the magnetic constriction. Constriction can reduce the total energy requirement of the funnel by a factor of 5 and not affect the differential emission in flow-dominated models.

  13. Balancing energy flexibilities through aggregation

    Valsomatzis, Emmanouil; Hose, Katja; Pedersen, Torben Bach

    2014-01-01

    in both energy production and consumption, is the key to solving these problems. Flexibilities can be expressed as flex-offers, which due to their high number need to be aggregated to reduce the complexity of energy scheduling. In this paper, we discuss balance aggregation techniques that already......One of the main goals of recent developments in the Smart Grid area is to increase the use of renewable energy sources. These sources are characterized by energy fluctuations that might lead to energy imbalances and congestions in the electricity grid. Exploiting inherent flexibilities, which exist...... during aggregation aim at balancing flexibilities in production and consumption to reduce the probability of congestions and reduce the complexity of scheduling. We present results of our extensive experiments....

  14. Balanced Unemployment in Polish Economy

    Kamila Szymańska

    2009-01-01

    The article deals with the problem of balanced unemployment in relation to the Polish economy. This issue with its variety considerations and economic, social and political implications is today one of the most important matter. Author analyses this problem together with its reasons and refer it to the Polish economy. In first and second part of the text there are presented basic assumptions of natural unemployment theory and Non-Accelerating Inflation Rate of Unemployment. Third part is an a...

  15. Balance of International Payments Matters!

    Li Zhen

    2010-01-01

    @@ For decades, China's export-oriented economic growth pattern has been constantly criticized as the culprit that destroys the world economic balance. Especially,at a time when the most serious economic crisis ever since the Great Depression is about to end, outcries from economically developed countries that China should do more to rebalance global economy have frequently made the headlines of various media coverage.

  16. Universally Balanced Combinatorial Optimization Games

    Xiaotie Deng; Gabrielle Demange

    2010-01-01

    This article surveys studies on universally balanced properties of cooperative games defined in a succinct form. In particular, we focus on combinatorial optimization games in which the values to coalitions are defined through linear optimization programs, possibly combinatorial, that is subject to integer constraints. In economic settings, the integer requirement reflects some forms of indivisibility. We are interested in the classes of games that guarantee a non-empty core no matter what ar...

  17. Balanced input-output assignment

    Gawronski, W.; Hadaegh, F. Y.

    1989-01-01

    Actuator/sensor locations and balanced representations of linear systems are considered for a given set of controllability and observability grammians. The case of equally controlled and observed states is given special attention. The assignability of grammians is examined, and the conditions for their existence are presented, along with several algorithms for their determination. Although an arbitrary positive semidefinite matrix is not always assignable, the identity grammian is shown to be always assignable. The results are extended to the case of flexible structures.

  18. Carbon balance in Mediterranean ecosystems

    Correia, Alexandra Cristina Pires

    2013-01-01

    Forests play an important role in climate change mitigation as they sequester and store carbon dioxide (CO2) from the atmosphere. The aim of this thesis was to investigate forest carbon balance in its main compartments: tress, understory and soils. We present methods to estimate carbon stock in biomass of stone pine stands in south Portugal. Allometric models, as well as conversion and expansion factors were presented allowing the quantification of stand carbon stocks irrespect...

  19. Momentum balance in wall jets

    Johansson, T. Gunnar; Mehdi, Faraz; Naughton, Jonathan W.

    2012-11-01

    A plane wall jet experiment has been done to study its momentum balance. Two component laser Doppler anemometry was used to simultaneously measure the axial and wall-normal velocity components in 6 axial positions (x/H= 25, 50, 75, 100, 125 and 150) spanning from the wall all the way well into the ambient stagnant area. In this way not only the mean velocity components and Reynolds normal and shear stresses but also all their spatial derivatives were determined. In addition the wall shear stress was measured in all six axial positions using oil film interferometry. From these data all terms in the x-momentum equation, except the pressure term, could be evaluated. Later also the pressure was measured in the same profiles, and thereby also the pressure term was included in the balance. Contrary to common belief it was found that the pressure was not constant in the wall jet. The complete momentum balance is discussed and used to evaluate the roles played by the different contributing terms in different regions of the flow field in an effort to improve on our understanding of the mechanics of wall jets.

  20. Constrained Allocation Flux Balance Analysis

    Mori, Matteo; Hwa, Terence; Martin, Olivier C.

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an “ensemble averaging” procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  1. Efficacy of virtual reality-based balance training versus the Biodex balance system training on the body balance of adults

    Ibrahim, Manal S.; Mattar, Ayman G.; Elhafez, Salam M.

    2016-01-01

    [Purpose] This study investigated efficacy of virtual reality (VR)-based balance training on enhancing balance and postural reactions of adults as a low-cost new modality compared to the established Biodex Balance System (BBS). [Subjects] Thirty normal adults of both genders were divided randomly into two equal-sized experimental groups of 15: BBS balance training and VR balance training. [Methods] The training programmes were conducted in 12 sessions, three 15-min sessions per week. The Nintendo® Wii Fit Plus (NWFP) and its balance board were used to train of the VR group. Each participant answered a questionnaire concerning usability, enjoyment, balance improvement, and fatigue at the end of the training programs. [Results] The study found a significant increase the measure of mean overall balance (OLB) in both groups. No significant difference was found between the groups, but a significant decrease in the mean balance-test time was found for both groups, with no significant difference between the two training methods. The VR programme was rated highly enjoyable by 81.8% of the group. [Conclusion] The Wii Fit Plus system with the balance board as a new VR balance-training technique, can be considered an effective and enjoyable tool for the training of adults’ body balance. PMID:26957722

  2. Efficacy of virtual reality-based balance training versus the Biodex balance system training on the body balance of adults.

    Ibrahim, Manal S; Mattar, Ayman G; Elhafez, Salam M

    2016-01-01

    [Purpose] This study investigated efficacy of virtual reality (VR)-based balance training on enhancing balance and postural reactions of adults as a low-cost new modality compared to the established Biodex Balance System (BBS). [Subjects] Thirty normal adults of both genders were divided randomly into two equal-sized experimental groups of 15: BBS balance training and VR balance training. [Methods] The training programmes were conducted in 12 sessions, three 15-min sessions per week. The Nintendo(®) Wii Fit Plus (NWFP) and its balance board were used to train of the VR group. Each participant answered a questionnaire concerning usability, enjoyment, balance improvement, and fatigue at the end of the training programs. [Results] The study found a significant increase the measure of mean overall balance (OLB) in both groups. No significant difference was found between the groups, but a significant decrease in the mean balance-test time was found for both groups, with no significant difference between the two training methods. The VR programme was rated highly enjoyable by 81.8% of the group. [Conclusion] The Wii Fit Plus system with the balance board as a new VR balance-training technique, can be considered an effective and enjoyable tool for the training of adults' body balance. PMID:26957722

  3. Towards balanced development in Pakistan.

    Pyatt, G

    1992-01-01

    Pakistan is a country whose economic growth is surprising in light of its social indicators. The aim of this article is to examine why conditions are such and to develop a framework for understanding the issues as an aid to redesigning policies. 5 sections are devoted to a summary of the main findings, the diagnosis of development and the impact on social sectors, a proposal for balanced development, and implications for policy changes. A sound macro economic context is needed with reforms economically in price and incentive systems, institutionally, and in the law and order sector. Public administration needs to be improved and individual opportunities need to be expanded. Internal security needs to be secured, so that law and order are restored. Economic growth has been high between 1960 and 1988, due to exploitation of natural resources and cheap unskilled labor, expansion of irrigated land, and growth of the unregulated informal sector. The major constraints on economic growth will come from a lack of fiscal discipline. 40% of government revenues are consumed by the military and 20% for servicing debt. Other constraints are the population growth rate in excess of 3%/year, an urban bias in allocation of resources, neglected primary education, and gender bias in education. There has been little incentive for provincial governments to balance budgets, and civil service has become disorganized. Balanced development entails recognizing human capital, natural resources, and infrastructure; accepting the status quo; and creating and maintaining an institutional framework to correct market failures and promote individual opportunities. The environmental polluter must pay. Income must be increased through higher wages, increasing the demand for labor, and transfers to households in the form of food rations, schooling, and medical care. Investment in women will increase household earnings, and improve living conditions and the health of themselves and their children

  4. Pitfalls in Using the Balanced Scorecard

    Nørreklit, Hanne; Jakobsen, Morten; Mitchell, Falconer

    2008-01-01

    The balanced scorecard has quickly become a leading management tool. But business performance measurement is notoriously difficult, so any system, including the balanced scorecard, is likely to have unanticipated and often dysfunctional consequences. This article briefly reviews the main attracti...

  5. On Water Balance of the Black Sea

    We consider the problems concerning the water balance of the Black Sea. According to the new data river discharge is determined on the basis of which component elements of water balance are adjusted. (authors)

  6. Fast balanced sampling for highly stratified population

    Hasler, Caren; Tillé, Yves

    2016-01-01

    Balanced sampling is a very efficient sampling design when the variable of interest is correlated to the auxiliary variables on which the sample is balanced. A procedure to select balanced samples in a stratified population has previously been proposed. Unfortunately, this procedure becomes very slow as the number of strata increases and it even fails to select samples for some large numbers of strata. A new algorithm to select balanced samples in a stratified population is proposed. This new...

  7. IMPLEMENTASI BALANCED SCORECARD PADA ORGANISASI PUBLIK

    Imelda R. H. N Imelda R. H. N

    2004-01-01

    At first introduced, balance scorecard is used by bussiness organization to measure performance of their activities, now balance scorecard is also used by public organization. A Public Organization is an organization intends to provide services to public, not for seeking profits. In order to used by public organization, a balance scorecard need to be modified. This essay discusses how to build a balance scorecard, which includes strategic goals, measures, targets, initiatives, and implementin...

  8. The Balanced Cube: A Concurrent Data Structure

    Dally, William J.; Seitz, Charles L.

    1985-01-01

    This paper describee the balanced cube, a new data structure for implementing ordered seta. Conventional dats structures such as heaps, balanced trees and B-trees have root bottlenecks which limit their potential concurrency and make them unable to take advantage of the computing potential of concurrent machines. The balanced cube achieves greater concurrency by eliminating the root bottleneck; an operation in the balanced cube can be initiated from any node. The throughput of ...

  9. Metal effect on the supramolecular structure, photophysics, and acid-base character of trinuclear pyrazolato coinage metal complexes.

    Omary, Mohammad A; Rawashdeh-Omary, Manal A; Gonser, M W Alexander; Elbjeirami, Oussama; Grimes, Tom; Cundari, Thomas R; Diyabalanage, Himashinie V K; Gamage, Chammi S Palehepitiya; Dias, H V Rasika

    2005-11-14

    Varying the coinage metal in cyclic trinuclear pyrazolate complexes is found to significantly affect the solid-state packing, photophysics, and acid-base properties. The three isoleptic compounds used in this study are [[3,5-(CF3)2Pz]M]3 with M = Cu, Ag, and Au (i.e., Cu3, Ag3, and Au3, respectively). They form isomorphous crystals and exist as trimers featuring nine-membered M3N6 rings with linear two-coordinate metal sites. On the basis of the M-N distances, the covalent radii of two-coordinate Cu(I), Ag(I), and Au(I) were estimated as 1.11, 1.34, and 1.25 angstroms, respectively. The cyclic [[3,5-(CF3)2Pz]M]3 complexes pack as infinite chains of trimers with a greater number of pairwise intertrimer M...M interactions upon proceeding to heavier coinage metals. However, the intertrimer distances are conspicuously short in Ag3 (3.204 angstroms) versus Au3 (3.885 angstroms) or Cu3 (3.813 angstroms) despite the significantly larger covalent radius of Ag(I). Remarkable luminescence properties are found for the three M3 complexes, as manifested by the appearance of multiple unstructured phosphorescence bands whose colors and lifetimes change qualitatively upon varying the coinage metal and temperature. The multiple emissions are assigned to different phosphorescent excimeric states that exhibit enhanced M...M bonding relative to the ground state. The startling luminescence thermochromic changes in crystals of each compound are related to relaxation between the different phosphorescent excimers. The trend in the lowest energy phosphorescence band follows the relative triplet energy of the three M(I) atomic ions. DFT calculations indicate that [[3,5-(R)2Pz]M]3 trimers with R = H or Me are bases with the relative basicity order Ag < Cu < Au while fluorination (R = CF3) renders even the Au trimer acidic. These predictions were substantiated experimentally by the isolation of the first acid-base adduct, [[Au3]2:toluene]infinity, in which a trinuclear Au(I) complex acts as

  10. Acid/base bifunctional carbonaceous nanomaterial with large surface area: Preparation, characterization, and adsorption properties for cationic and anionic compounds

    Li, Kai; Ma, Chun–Fang; Ling, Yuan; Li, Meng [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Gao, Qiang, E-mail: gaoqiang@cug.edu.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Engineering Research Center of Nano-Geo Materials of Ministry of Education, China University of Geosciences, Wuhan 430074 (China); Luo, Wen–Jun, E-mail: heartnohome@yahoo.com.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China)

    2015-07-15

    Nanostructured carbonaceous materials are extremely important in the nano field, yet developing simple, mild, and “green” methods that can make such materials possess large surface area and rich functional groups on their surfaces still remains a considerable challenge. Herein, a one-pot and environment-friendly method, i.e., thermal treatment (180 °C; 18 h) of water mixed with glucose and chitosan (CTS), has been proposed. The resultant carbonaceous nanomaterials were characterized by field emitting scanning electron microscope, N{sub 2} adsorption/desorption, Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, and zeta-potential analysis. It was found that, in contrast to the conventional hydrothermally carbonized product from pure glucose, with low surface area (9.3 m{sup 2} g{sup −1}) and pore volume (0.016 cm{sup 3} g{sup −1}), the CTS-added carbonaceous products showed satisfactory textural parameters (surface area and pore volume up to 254 m{sup 2} g{sup −1} and 0.701 cm{sup 3} g{sup −1}, respectively). Moreover, it was also interestingly found that these CTS-added carbonaceous products possessed both acidic (–COOH) and basic (–NH{sub 2}) groups on their surfaces. Taking the advantages of large surface area and –COOH/–NH{sub 2} bifunctional surface, the carbonaceous nanomaterials exhibited excellent performance for adsorptions of cationic compound (i.e., methylene blue) at pH 10 and anionic compound (i.e., acid red 18) at pH 2, respectively. This work not only provides a simple and green route to prepare acid/base bifunctional carbonaceous nanomaterials with large surface area but also well demonstrates their potential for application in adsorption. - Highlights: • A simple and green method was proposed to prepare carbon nanomaterials. • The carbon product showed acid/base bifunctional surface with large surface area. • The carbon material could efficiently adsorb both cationic and anionic compounds.

  11. Monte Carlo methods beyond detailed balance

    Schram, Raoul D.; Barkema, Gerard T.

    2015-01-01

    Monte Carlo algorithms are nearly always based on the concept of detailed balance and ergodicity. In this paper we focus on algorithms that do not satisfy detailed balance. We introduce a general method for designing non-detailed balance algorithms, starting from a conventional algorithm satisfying

  12. Balancing of Lossless and Passive Systems

    Schaft, Arjan van der

    2008-01-01

    Different balancing techniques are applied to lossless nonlinear systems, with open-loop balancing applied to their scattering representation. It is shown that they all lead to the same result: the pair of to-be-balanced functions is given by two copies of the physical energy function, yielding thus

  13. Energy balances for power plants

    An important aspect of a power plant is its energy balance, i.e. the electrical energy produced by the plant over its overall operation period, compared to the amount of non-renewable energy used to create and build the plant. Tense discussions took place in the past between criticizers and promotors of a given technology, some technologies even being accused of having a negative energy balance. Mostly based on built examples the present study aims at giving objective data for the represented technologies, as follows: a 64 MW hydro power plant in the Alps, with seasonal water storage in a lake; a 60 MW run-of-river high-head hydro power plant in the Alps; two run-of-river low-head hydro power plants in the Swiss Midlands (14 MW and 25 MW respectively); a small 30 kW wind power generator located near the Simplon Pass at 2000 m over sea level, in the Alps; a 3 kW photovoltaic generator in the roof of a single-family house; a 500 kW photovoltaic power plant in the Jura, at 1000 m over sea level; a 0.9 MWel/8.8 MWtherm fossil-fuel co-generation plant near Zuerich; a 200 MW natural-gas-fired gas/vapour turbine power plant; a 300 MW heavy-fuel-fired power plant; a 500 MW coal-fired power plant; and the Leibstadt 990 MW nuclear power plant. The best energy balances are obtained for the hydro power plants, the worst for the Leibstadt nuclear power plant. In between the photovoltaic plants and the fossil-fuel-fired plants are found. The figures differ by more than two orders of magnitude

  14. Effectiveness of the Balanced Scorecard

    Lichen, Alex Yu; Perera, Sujatha; Crowe, Susan

    2008-01-01

    Many of the claimed benefits of the Balanced Scorecard (BSC) rely on the linkage of its performance measures to strategy and on causal relations among its measures. Using a survey research method, this study examines the extent to which adopters of BSC consider these features and whether they...... result in more effective performance measurement systems. A survey of medium and large Australian manufacturing organisations reveals that varying forms of scorecards are used in practice and that managers who perceive that their scorecard measures are linked to strategy and affect each other in a causal...

  15. Character Balance in MOBA Games

    Teodor, Norén; Emanuel, Palm

    2015-01-01

    As live streaming of video games has become easier, electronic sports have grown quickly and they are still increasing as tournaments grow in viewers and prizes. The purpose of this paper is to examine the theory Metagame Bounds by applying it to League of Legends and Dota 2, to see if it is a valid way of looking at character balance in the Multiplayer Online Battle Arena game genre. The main mode of both games consist of matches played on a map where a team of five players is up against ano...

  16. Electronic Elections: A Balancing Act

    Rezende, Pedro A. D.

    This article aims to share some major lessons learned from the pioneering experience in Brazil with the world's first full national implementation of universal electronic voting. Differing notions of security, and their "collateral entanglements", appear to play a key role and are contrasted in Brazil's pioneering electronic voting saga. After an introduction, we puzzle through what election security may mean. We elaborate on how technological innovations may affect the underlying risks, their nature, corrections and balance. Then we describe some ways in which innovations have been deployed and validated, and how the results are being perceived, before some closing remarks.

  17. The Balance Idea of Integration

    2004-01-01

    @@ Changes in the content of European balance constitute the biggest difference between the economic integration model and its predecessors. Armament, territory and resources were considered as key factors for enhanced strength and sustained power parity with other nations. Transition to economic integration has however entailed decoupling of the two. Enhanced national strength now aims instead at power parity and shared power based on common European interests and inter-dependency rather than at weakening other nations. As a result, state relations there are moving toward fusion and convergence.

  18. Equilibria in Load Balancing Games

    Bo Chen

    2009-01-01

    A Nash equilibrium (NE) in a multi-agent game is a strategy profile that is resilient to unilateral deviations.A strong Nash equilibrium (SE) is one that is stable against coordinated deviations of any coalition.We show that,in the load balancing games,NEs approximate SEs in the sense that the benefit of each member of any coalition from coordinated deviations is well limited.Furthermore,we show that an easily recognizable special subset of NEs exhibit even better approximation of SEs.

  19. Energy balances of OECD countries

    Contains a compilation of data on the supply and consumption of coal, oil, gas, electricity, heat, combustible renewable and waste presented in energy balances. The figures are expressed in million tonnes of oil equivalent. Historical tables summarize key energy and economic indicators as well as production, trade and final consumption data. Each issue includes definitions of products and flows and explanatory notes on the individual country data as well as conversion factors from original units to tonnes of oil equivalent. In the 1997 edition, key indicators have been provided back to 1960 instead of 1971 as in the previous editions. (author)

  20. Kinetics and mechanisms of the acid-base reaction between NH$_3$ and HCOOH in interstellar ice analogs

    Bergner, Jennifer B; Rajappan, Mahesh; Fayolle, Edith C

    2016-01-01

    Interstellar complex organic molecules (COMs) are commonly observed during star formation, and are proposed to form through radical chemistry in icy grain mantles. Reactions between ions and neutral molecules in ices may provide an alternative cold channel to complexity, as ion-neutral reactions are thought to have low or even no energy barriers. Here we present a study of a the kinetics and mechanisms of a potential ion-generating acid-base reaction between NH$_{3}$ and HCOOH to form the salt NH$_{4}^{+}$HCOO$^{-}$. We observe salt growth at temperatures as low as 15K, indicating that this reaction is feasible in cold environments. The kinetics of salt growth are best fit by a two-step model involving a slow "pre-reaction" step followed by a fast reaction step. The reaction energy barrier is determined to be 70 $\\pm$ 30K with a pre-exponential factor 1.4 $\\pm$ 0.4 x 10$^{-3}$ s$^{-1}$. The pre-reaction rate varies under different experimental conditions and likely represents a combination of diffusion and or...

  1. Novel pH-sensitive polysialic acid based polymeric micelles for triggered intracellular release of hydrophobic drug.

    Zhang, Wuxia; Dong, Dongqi; Li, Peng; Wang, Dongdong; Mu, Haibo; Niu, Hong; Duan, Jinyou

    2016-03-30

    Polysialic acid (PSA), a non-immunogenic and biodegradable natural polymer, is prone to hydrolysis under endo-lysosomal pH conditions. Here, we synthesized an intracellular pH-sensitive polysialic acid-ursolic acid conjugate by a condensation reaction. To further test the drug loading capability, we prepared paclitaxel-loaded polysialic acid-based amphiphilic copolymer micelle (PTX-loaded-PSAU) by a nanoprecipitation method. Results showed PTX-loaded-PSAU exhibited well-defined spherical shape and homogeneous distribution. The drug-loading was 4.5% with an entrapment efficiency of 67.5%. PTX released from PTX-loaded-PSAU was 15% and 42% in 72 h under simulated physiological condition (pH 7.4) and mild acidic conditions (pH 5.0), respectively. In addition, In vitro cytotoxicity assay showed that PTX-loaded-PSAU retained anti-tumor (SGC-7901) activity with a cell viability of 53.8% following 72 h incubation, indicating PTX-loaded-PSAU could efficiently release PTX into the tumor cells. These results indicated that the pH-responsive biodegradable PTX-loaded-PSAU possess superior extracellular stability and intracellular drug release ability. PMID:26794949

  2. Insight into acid-base nucleation experiments by comparison of the chemical composition of positive, negative, and neutral clusters.

    Bianchi, Federico; Praplan, Arnaud P; Sarnela, Nina; Dommen, Josef; Kürten, Andreas; Ortega, Ismael K; Schobesberger, Siegfried; Junninen, Heikki; Simon, Mario; Tröstl, Jasmin; Jokinen, Tuija; Sipilä, Mikko; Adamov, Alexey; Amorim, Antonio; Almeida, Joao; Breitenlechner, Martin; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Laaksonen, Ari; Lawler, Michael J; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Tomé, António; Virtanen, Annele; Viisanen, Yrjö; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Curtius, Joachim; Kulmala, Markku; Worsnop, Douglas R; Donahue, Neil M; Baltensperger, Urs

    2014-12-01

    We investigated the nucleation of sulfuric acid together with two bases (ammonia and dimethylamine), at the CLOUD chamber at CERN. The chemical composition of positive, negative, and neutral clusters was studied using three Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometers: two were operated in positive and negative mode to detect the chamber ions, while the third was equipped with a nitrate ion chemical ionization source allowing detection of neutral clusters. Taking into account the possible fragmentation that can happen during the charging of the ions or within the first stage of the mass spectrometer, the cluster formation proceeded via essentially one-to-one acid-base addition for all of the clusters, independent of the type of the base. For the positive clusters, the charge is carried by one excess protonated base, while for the negative clusters it is carried by a deprotonated acid; the same is true for the neutral clusters after these have been ionized. During the experiments involving sulfuric acid and dimethylamine, it was possible to study the appearance time for all the clusters (positive, negative, and neutral). It appeared that, after the formation of the clusters containing three molecules of sulfuric acid, the clusters grow at a similar speed, independent of their charge. The growth rate is then probably limited by the arrival rate of sulfuric acid or cluster-cluster collision. PMID:25406110

  3. Questioning As a Pedagogical Tool for Eliciting Student Generated Questions During the Teaching of Acid-base Equilibria

    Ayoade Ejiwale Okanlawon

    2012-04-01

    Full Text Available Traditionally, teachers simply taught problem-solving by explaining the worked-out examples taken from textbooks and students were expected to listen quietly, copy the solution to the problem, and then work independently at their desks. But a large body of research notes that guiding students to develop a solution pathway with questioning is more effective than simply explaining the sequence of steps to solve the problem. Students involved in question- and-answer sessions are more attentive than those who listen passively to teacher explanations and they are more likely to generate questions. The questions students ask during a lesson perform a number of important functions, including providing the teacher with valuable information about students’ understanding and misunderstanding, fostering self-regulation, inviting classroom discussions and aiding comprehension of contents presented. The skill of posing questions during classroom instruction is often under-valued and under taught in today’s classrooms. To encourage students to ask quality and thought provoking questions related to the contents taught, explicit instruction is required. This paper, therefore, qualitatively reports factors that foster student generated questions during the problem-solving instruction involving acid-base titration problem.

  4. A facile nanoaggregation strategy for oral delivery of hydrophobic drugs by utilizing acid-base neutralization reactions

    Chen Huabing; Wan Jiangling; Wang Yirui; Mou Dongsheng; Liu Hongbin; Xu Huibi; Yang Xiangliang [College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)], E-mail: yangxl@mail.hust.edu.cn

    2008-09-17

    Nanonization strategies have been used to enhance the oral availability of numerous drugs that are poorly soluble in water. Exploring a facile nanonization strategy with highly practical potential is an attractive focus. Here, we report a novel facile nanoaggregation strategy for constructing drug nanoparticles of poorly soluble drugs with pH-dependent solubility by utilizing acid-base neutralization in aqueous solution, thus facilitating the exploration of nanonization in oral delivery for general applicability. We demonstrate that hydrophobic itraconazole dissolved in acid solution formed a growing core and aggregated into nanoparticles in the presence of stabilizers. The nanoparticles, with an average diameter of 279.3 nm and polydispersity index of 0.116, showed a higher dissolution rate when compared with the marketed formulation; the average dissolution was about 91.3%. The in vivo pharmacokinetic studies revealed that the nanoparticles had a rapid absorption and enhanced oral availability. The diet state also showed insignificant impact on the absorption of itraconazole from nanoparticles. This nanoaggregation strategy is a promising nanonization method with a facile process and avoidance of toxic organic solvents for oral delivery of poorly soluble drugs with pH-dependent solubility and reveals a highly practical potential in the pharmaceutical and chemical industries.

  5. Ocean acidification increases copper toxicity differentially in two key marine invertebrates with distinct acid-base responses.

    Lewis, Ceri; Ellis, Robert P; Vernon, Emily; Elliot, Katie; Newbatt, Sam; Wilson, Rod W

    2016-01-01

    Ocean acidification (OA) is expected to indirectly impact biota living in contaminated coastal environments by altering the bioavailability and potentially toxicity of many pH-sensitive metals. Here, we show that OA (pH 7.71; pCO2 1480 μatm) significantly increases the toxicity responses to a global coastal contaminant (copper ~0.1 μM) in two keystone benthic species; mussels (Mytilus edulis) and purple sea urchins (Paracentrotus lividus). Mussels showed an extracellular acidosis in response to OA and copper individually which was enhanced during combined exposure. In contrast, urchins maintained extracellular fluid pH under OA by accumulating bicarbonate but exhibited a slight alkalosis in response to copper either alone or with OA. Importantly, copper-induced damage to DNA and lipids was significantly greater under OA compared to control conditions (pH 8.14; pCO2 470 μatm) for both species. However, this increase in DNA-damage was four times lower in urchins than mussels, suggesting that internal acid-base regulation in urchins may substantially moderate the magnitude of this OA-induced copper toxicity effect. Thus, changes in metal toxicity under OA may not purely be driven by metal speciation in seawater and may be far more diverse than either single-stressor or single-species studies indicate. This has important implications for future environmental management strategies. PMID:26899803

  6. Study of acid-base properties in various water-salt and water-organic solvent mixtures

    Acid-base reactions have been studied in water-salt mixtures and water organic solvent-mixtures. It has been possible to find some relations between the displacement of the equilibria and the numerical value of water activity in the mixture. First have been studied some equilibria H+ + B ↔ HB+ in salt-water mixtures and found a relation between the pKA value, the solubility of the base and water activity. The reaction HO- + H+ ↔ H2O has been investigated and a relation been found between pKi values, water activity and the molar concentration of the salt in the mixture. This relation is the same for every mixture. Then the same reactions have been studied in organic solvent-water mixtures and a relation found in the first part of the work have been used with success. So it has been possible to explain easily some properties of organic water-mixture as the shape of the curves of the Hammett acidity function Ho. (authors)

  7. The effect of acid-base clustering and ions on the growth of atmospheric nano-particles.

    Lehtipalo, Katrianne; Rondo, Linda; Kontkanen, Jenni; Schobesberger, Siegfried; Jokinen, Tuija; Sarnela, Nina; Kürten, Andreas; Ehrhart, Sebastian; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Sipilä, Mikko; Yli-Juuti, Taina; Duplissy, Jonathan; Adamov, Alexey; Ahlm, Lars; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Guida, Roberto; Hakala, Jani; Hansel, Armin; Jud, Werner; Kangasluoma, Juha; Kerminen, Veli-Matti; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Kupiainen-Määttä, Oona; Laaksonen, Ari; Lawler, Michael J; Leiminger, Markus; Mathot, Serge; Olenius, Tinja; Ortega, Ismael K; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud; Rissanen, Matti P; Ruuskanen, Taina; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Simon, Mario; Smith, James N; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Tomé, António; Vaattovaara, Petri; Vehkamäki, Hanna; Vrtala, Aron E; Wagner, Paul E; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Virtanen, Annele; Donahue, Neil M; Carslaw, Kenneth S; Baltensperger, Urs; Riipinen, Ilona; Curtius, Joachim; Worsnop, Douglas R; Kulmala, Markku

    2016-01-01

    The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere. PMID:27197574

  8. Continuous monitoring of the zinc-phosphate acid-base cement setting reaction by proton nuclear magnetic relaxation

    Apih, T.; Lebar, A.; Pawlig, O.; Trettin, R.

    2001-06-01

    Proton nuclear magnetic relaxation is a well-established technique for continuous and non destructive monitoring of hydration of conventional Portland building cements. Here, we demonstrate the feasibility of nuclear magnetic resonance (NMR) monitoring of the setting reaction of zinc-phosphate acid-base dental cements, which harden in minutes as compared to days, as in the case of Portland cements. We compare the setting of cement powder (mainly, zinc oxide) prepared with clinically used aluminum-modified orthophosphoric acid solution with the setting of a model system where cement powder is mixed with pure orthophosphoric acid solution. In contrast to previously published NMR studies of setting Portland cements, where a decrease of spin-lattice relaxation time is attributed to enhanced relaxation at the growing internal surface, spin-lattice relaxation time T1 increases during the set of clinically used zinc-phosphate cement. Comparison of these results with a detailed study of diffusion, viscosity, and magnetic-field dispersion of T1 in pure and aluminum-modified orthophosphoric acid demonstrates that the increase of T1 in the setting cement is connected with the increase of molecular mobility in the residual phosphoric acid solution. Although not taken into account so far, such effects may also significantly influence the relaxation times in setting Portland cements, particularly when admixtures with an effect on water viscosity are used.

  9. Cation transfer across a hydrogel/organic phase: Effect of cation size, hydrophobicity and acid-base properties

    Juarez, Ana V. [Departamento de Quimica Organica, IMBIV, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Yudi, Lidia M. [Departamento de Fisico Quimica, INFIQC, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Alvarez Igarzabal, Cecilia [Departamento de Quimica Organica, IMBIV, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Strumia, Miriam C., E-mail: mcs@fcq.unc.edu.a [Departamento de Quimica Organica, IMBIV, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2010-02-28

    The transfers of tetraethylammonium (TEA{sup +}) and protonated triflupromazine (HTFP{sup +}) through a hydrogel/liquid interface (g/o) and a liquid/liquid interface (w/o) were compared using cyclic voltammetry. After the two phases were put in contact, the behavior of each molecule was analyzed at different pH values and at different time points. The gel induces hydrophobic and electrostatic interactions with TEA{sup +} and HTFP{sup +}, shifting the peak potentials to more positive values. The diffusion coefficients, D, in both phases (g and w) at different pH values were calculated. In the case of TEA{sup +}, the D value remains constant in both systems. However, the D value of HTFP{sup +} is lower in the gel phase than in the liquid phase. HTFP{sup +} is transferred from the aqueous phase to the organic phase via a direct mechanism that involves coupled acid-base and partition processes. At the g/o interface, the coupled chemical reactions of HTFP{sup +} were inhibited by the drug/gel interaction. The results demonstrate that the g/o system could be used as a model to study the controlled release of charged drugs.

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

    Gao Qianqian

    2012-03-01

    Full Text Available Abstract 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.

  11. Electronic absorption study on acid-base equilibria for some pyrimidine derivatives containing semi- and thiosemicarbazone moiety

    Kılıç, H.

    2010-02-01

    The UV-vis spectra of recently synthesized 5-benzoyl-1-(methylphenylmethyleneamino)-4-phenyl-1H-pyrimidine-2-one, ( I), and 5-benzoyl-1-(methylphenylmethyleneamino)-4-phenyl-1H-pyrimidine-2-thione, ( II) were studied in aqueous methanol (5%, v/v methanol). The nature of the electronic transitions and the roles of carbonyl oxygen of I and thiocarbonyl sulfur of II on the behavior of UV-vis spectra were discussed. Acid-base equilibria of the compounds against varying pH and p Ka values related equilibria were determined at an ionic strength of 0.10 M by using the Henderson-Haselbalch equation. The mean acidity constants for the protonated forms of the compounds were determined as p Ka1 = 5.121, p Ka2 = 7.929 and p Ka3 = 11.130 for I and p Ka1 = 4.684, p Ka2 = 7.245 and p Ka3 = 10.630 for II. The preferred dissociation mechanisms were discussed based on UV-vis data and a mechanism was proposed for each compound.

  12. A facile nanoaggregation strategy for oral delivery of hydrophobic drugs by utilizing acid-base neutralization reactions

    Nanonization strategies have been used to enhance the oral availability of numerous drugs that are poorly soluble in water. Exploring a facile nanonization strategy with highly practical potential is an attractive focus. Here, we report a novel facile nanoaggregation strategy for constructing drug nanoparticles of poorly soluble drugs with pH-dependent solubility by utilizing acid-base neutralization in aqueous solution, thus facilitating the exploration of nanonization in oral delivery for general applicability. We demonstrate that hydrophobic itraconazole dissolved in acid solution formed a growing core and aggregated into nanoparticles in the presence of stabilizers. The nanoparticles, with an average diameter of 279.3 nm and polydispersity index of 0.116, showed a higher dissolution rate when compared with the marketed formulation; the average dissolution was about 91.3%. The in vivo pharmacokinetic studies revealed that the nanoparticles had a rapid absorption and enhanced oral availability. The diet state also showed insignificant impact on the absorption of itraconazole from nanoparticles. This nanoaggregation strategy is a promising nanonization method with a facile process and avoidance of toxic organic solvents for oral delivery of poorly soluble drugs with pH-dependent solubility and reveals a highly practical potential in the pharmaceutical and chemical industries

  13. Continuous monitoring of the zinc-phosphate acid-base cement setting reaction by proton nuclear magnetic relaxation

    Proton nuclear magnetic relaxation is a well-established technique for continuous and non destructive monitoring of hydration of conventional Portland building cements. Here, we demonstrate the feasibility of nuclear magnetic resonance (NMR) monitoring of the setting reaction of zinc-phosphate acid-base dental cements, which harden in minutes as compared to days, as in the case of Portland cements. We compare the setting of cement powder (mainly, zinc oxide) prepared with clinically used aluminum-modified orthophosphoric acid solution with the setting of a model system where cement powder is mixed with pure orthophosphoric acid solution. In contrast to previously published NMR studies of setting Portland cements, where a decrease of spin-lattice relaxation time is attributed to enhanced relaxation at the growing internal surface, spin-lattice relaxation time T1 increases during the set of clinically used zinc-phosphate cement. Comparison of these results with a detailed study of diffusion, viscosity, and magnetic-field dispersion of T1 in pure and aluminum-modified orthophosphoric acid demonstrates that the increase of T1 in the setting cement is connected with the increase of molecular mobility in the residual phosphoric acid solution. Although not taken into account so far, such effects may also significantly influence the relaxation times in setting Portland cements, particularly when admixtures with an effect on water viscosity are used. [copyright] 2001 American Institute of Physics

  14. The effect of oral sodium acetate administration on plasma acetate concentration and acid-base state in horses

    Lindinger Michael I

    2007-12-01

    Full Text Available Abstract Aim Sodium acetate (NaAcetate has received some attention as an alkalinizing agent and possible alternative energy source for the horse, however the effects of oral administration remain largely unknown. The present study used the physicochemical approach to characterize the changes in acid-base status occurring after oral NaAcetate/acetic acid (NAA administration in horses. Methods Jugular venous blood was sampled from 9 exercise-conditioned horses on 2 separate occasions, at rest and for 24 h following a competition exercise test (CET designed to simulate the speed and endurance test of 3-day event. Immediately after the CETs horses were allowed water ad libitum and either: 1 8 L of a hypertonic NaAcetate/acetic acid solution via nasogastric tube followed by a typical hay/grain meal (NAA trial; or 2 a hay/grain meal alone (Control trial. Results Oral NAA resulted in a profound plasma alkalosis marked by decreased plasma [H+] and increased plasma [TCO2] and [HCO3-] compared to Control. The primary contributor to the plasma alkalosis was an increased [SID], as a result of increased plasma [Na+] and decreased plasma [Cl-]. An increased [Atot], due to increased [PP] and a sustained increase in plasma [acetate], contributed a minor acidifying effect. Conclusion It is concluded that oral NaAcetate could be used as both an alkalinizing agent and an alternative energy source in the horse.

  15. Fabrication and characterization of elastomeric scaffolds comprised of a citric acid-based polyester/hydroxyapatite microcomposite

    Highlights: • Porous scaffolds were prepared from polymer/hydroxyapatite (POC/HA) composite. • The pore size was designed to be uniform for all POC/HA composite scaffolds. • Compression strength and modulus are dependent on HA concentration within composite. - Abstract: In this paper we describe an effective technical route for the production of porous scaffolds from microcomposite material consistent of citric acid-based polyester elastomer and hydroxyapatite microparticles with potential use in tissue engineering applications. Fabricated scaffolds were characterized by field emission electron microscopy, Fourier-transform infra-red spectroscopy, thermal gravimetric analysis and mechanical tests. We demonstrate that the chemical composition, scaffold morphology, mechanical integrity and porosity of the produced microcomposite scaffolds are strongly affected by variation of the initial hydroxyapatite concentration in the mineral-polymer mixture during the fabrication process. This polyester/mineral scaffold exhibits versatility in compression modulus and strength in the range of 21.72–33.25 KPa and 49.92–101.48 KPa respectively, corresponding to the hydroxyapatite concentration in the composite (10–30 wt.%)

  16. Contributions of separate reactions to the acid-base buffering of soils in brook floodplains (Central Forest State Reserve)

    Sokolova, T. A.; Tolpeshta, I. I.; Rusakova, E. S.

    2016-04-01

    The acid-base buffering of gleyic gray-humus soils developed in brook floodplains and undisturbed southern-taiga landscapes has been characterized by the continuous potentiometric titration of soil water suspensions. During the interaction with an acid, the major amount of protons (>80%) is consumed for the displacement of exchangeable bases and the dissolution of Ca oxalates. In the O and AY horizons, Mn compounds make the major contribution (2-15%) to the acid buffering. The buffer reactions with the participation of Al compounds make up from 0.5 to 1-2% of the total buffering capacity, and the protonation of the surface OH groups of kaolinite consumes 2-3% of the total buffering capacity. The deprotonation of OH groups on the surface of Fe hydroxides (9-43%), the deprotonation of OH groups on the surface of illite crystals (3-19%), and the dissolution of unidentified aluminosilicates (9-14%) are the most significant buffer reactions whose contributions have been quantified during the interaction with a base. The contribution of the deprotonation of OH groups on the surface of kaolinite particles is lower (1-5%) because of the small specific surface area of this mineral, and that of the dissolution of Fe compounds is insignificant. In the AY horizon, the acid and base buffering of soil in the rhizosphere is higher than beyond the rhizosphere because of the higher contents of organic matter and nonsilicate Fe and Al compounds.

  17. Coupled Cluster Evaluation of the Stability of Atmospheric Acid-Base Clusters with up to 10 Molecules.

    Myllys, Nanna; Elm, Jonas; Halonen, Roope; Kurtén, Theo; Vehkamäki, Hanna

    2016-02-01

    We investigate the utilization of the domain local pair natural orbital coupled cluster (DLPNO-CCSD(T)) method for calculating binding energies of atmospherical molecular clusters. Applied to small complexes of atmospherical relevance we find that the DLPNO method significantly reduces the scatter in the binding energy, which is commonly present in DFT calculations. For medium sized clusters consisting of sulfuric acid and bases the DLPNO method yields a systematic underestimation of the binding energy compared to canonical coupled cluster results. The errors in the DFT binding energies appear to be more random, while the systematic nature of the DLPNO results allows the establishment of a scaling factor, to better mimic the canonical coupled cluster calculations. Based on the trends identified for the small and medium sized systems, we further extend the application of the DLPNO method to large acid - base clusters consisting of up to 10 molecules, which have previously been out of reach with accurate coupled cluster methods. Using the Atmospheric Cluster Dynamics Code (ACDC) we compare the sulfuric acid dimer formation based on the new DLPNO binding energies with previously published RI-CC2/aug-cc-pV(T+d)Z results. We also compare the simulated sulfuric acid dimer concentration as a function of the base concentration with measurement data from the CLOUD chamber and flow tube experiments. The DLPNO method, even after scaling, underpredicts the dimer concentration significantly. Reasons for this are discussed. PMID:26771121

  18. Engine balance apparatus and accessory drive device

    Brogdon, James William (Inventor); Gill, David Keith (Inventor)

    2000-01-01

    A balancing mechanism for an engine that has a rotating crankshaft and reciprocating pistons such as those engines used in automobiles, aircrafts, boats, piston-driven compressors, piston-driven slider crank mechanisms, etc. The present balancing mechanism may comprise a first balance mass non-rotatably affixed to the crankshaft and a second balance mass rotatably supported on the crankshaft. A driver assembly is affixed to crankshaft to cause the second balance mass to rotate in a direction that is opposite to the direction in which the crank shaft is rotating. The driver assembly may include auxiliary gears configured to transport rotary power to auxiliary components.

  19. The balanced tensor product of module categories

    Douglas, Christopher L.; Schommer-Pries, Christopher; Snyder, Noah

    2014-01-01

    The balanced tensor product M (x)_A N of two modules over an algebra A is the vector space corepresenting A-balanced bilinear maps out of the product M x N. The balanced tensor product M [x]_C N of two module categories over a monoidal linear category C is the linear category corepresenting C-balanced right-exact bilinear functors out of the product category M x N. We show that the balanced tensor product can be realized as a category of bimodule objects in C, provided the monoidal linear cat...

  20. Pitfalls and Uncertainties of Using Potentiometric Titration for Estimation of Plant Roots Surface Charge and Acid-Base Properties

    Grzegorz Jozefaciuk; Alicja Szatanik-Kloc; Malgorzata Lukowska; Justyna Szerement

    2014-01-01

    Amount and properties of roots surface charge are important for nutrient uptake and balance in plants. Roots surface charge markedly varies at different rizosphere conditions (particularly pH and ionic strength), which can markedly alter during vegetation season. Among recently available measuring methods, surface charge-pH dependence of roots (as well as other biological objects) is most easily evaluated by potentiometric titration. Use of this method is also easy at d...

  1. IMPLEMENTASI BALANCED SCORECARD PADA ORGANISASI PUBLIK

    Imelda R. H. N Imelda R. H. N

    2004-01-01

    Full Text Available At first introduced, balance scorecard is used by bussiness organization to measure performance of their activities, now balance scorecard is also used by public organization. A Public Organization is an organization intends to provide services to public, not for seeking profits. In order to used by public organization, a balance scorecard need to be modified. This essay discusses how to build a balance scorecard, which includes strategic goals, measures, targets, initiatives, and implementing balance scorecard to public organization. Abstract in Bahasa Indonesia : Saat pertama kali diperkenalkan, balanced scorecard digunakan oleh organisasi bisnis untuk pengukuran kinerja. Dewasa ini, balanced scorecard tidak saja digunakan oleh organisasi bisnis tetapi juga organisasi publik. Organisasi publik adalah organisasi yang menyediakan jasa pada masyarakat dengan tujuan bukan untuk mencari profit. Untuk dapat digunakan oleh organisasi publik, balanced scorecard tersebut harus dimodifikasi. Tulisan ini membahas bagaimana membangun balanced scorecard, meliputi menentukan tujuan strategis, ukuran yang digunakan, target yang ingin dicapai serta inisiatif, dan mengimplementasikan balanced scorecard pada organisasi publik. Kata kunci: balanced scorecard, organisasi publik.

  2. A Comparative Study of the Effects of a Concept Mapping Enhanced Laboratory Experience on Turkish High School Students' Understanding of Acid-Base Chemistry

    Ozmen, Haluk; Demircioglu, Gokhan; Coll, Richard K.

    2009-01-01

    The research reported here consists of the introduction of an intervention based on a series of laboratory activities combined with concept mapping. The purpose of this intervention was to enhance student understanding of acid-base chemistry for tenth grade students' from two classes in a Turkish high school. An additional aim was to enhance…

  3. An Introduction to Multivariate Curve Resolution-Alternating Least Squares: Spectrophotometric Study of the Acid-Base Equilibria of 8-Hydroxyquinoline-5-Sulfonic Acid

    Rodriguez-Rodriguez, Cristina; Amigo, Jose Manuel; Coello, Jordi; Maspoch, Santiago

    2007-01-01

    A spectrophotometric study of the acid-base equilibria of 8-hydroxyquinoline-5-sulfonic acid to describe the multivariate curve resolution-alternating least squares algorithm (MCR-ALS) is described. The algorithm provides a lot of information and hence is of great importance for the chemometrics research.

  4. The Effect of Level of Information as Presented by Different Technologies on Students' Understanding of Acid, Base, and pH Concepts.

    Nakhleh, Mary B.; Krajcik, Joseph S.

    Within high school chemistry the topic of acids, bases, and pH is particularly challenging because robust understanding of the topic depends heavily on the student possessing deep concepts of atoms, molecules, ions, and chemical reactions. Since knowledge is acquired and stored in a dynamic structure, it was investigated in this study how…

  5. Involvement of placental/umbilical cord blood acid-base status and gas values on the radiosensitivity of human fetal/neonatal hematopoietic stem/progenitor cells

    Arterial cord blood (CB) acid-base status and gas values, such as pH, PCO2, PO2, HCO3- and base excess, provide useful information on the fetal and neonatal condition. However, it remains unknown whether these values affect the radiosensitivity of fetal/neonatal hematopoiesis. The present study evaluated the relationship between arterial CB acid-base status, gas values, and the radiosensitivity of CB hematopoietic stem/progenitor cells (HSPCs). A total of 25 CB units were collected. The arterial CB acid-base status and gas values were measured within 30 min of delivery. The CD34+ HSPCs obtained from CB were exposed to 2 Gy X-irradiation, and then assayed for colony-forming unit-granulocyte-macrophage, burst-forming unit-erythroid (BFU-E), and colony-forming unit-granulocyte erythroid, macrophage and megakaryocyte cells. Acid-base status and gas values for PCO2 and HCO3- showed a statistically significant negative correlation with the surviving fraction of BFU-E. In addition, a significant positive correlation was observed between gestational age and PCO2. Moreover, the surviving fraction of BFU-E showed a significant negative correlation with gestational age. Thus, HSPCs obtained from CB with high PCO2/HCO3- levels were sensitive to X-irradiation, which suggests that the status of arterial PCO2/HCO3- influences the radiosensitivity of fetal/neonatal hematopoiesis, especially erythropoiesis. (author)

  6. Field balancing in the real world

    Bracher, B.

    1997-09-05

    Field balancing can achieve significant results when other problems are present in the frequency spectrum and multiple vibrations are evident in the waveform. Many references suggest eliminating other problems before attempting to balance. That`s great - if you can do it. There are valid reasons for this approach, and it would be much easier to balance machinery when other problems have been corrected. It is the theoretical ideal in field balancing. However, in the real world of machinery maintained for years by reacting to immediate problems, the classic vibration signature for unbalance is rarely seen. Maintenance personnel make most of their decisions with limited information. The decision to balance or not to balance is usually made the same way. This paper will demonstrate significant results of field balancing in the presence of multiple problems. By examining the data available and analyzing the probabilities, a reasonable chance for success can be assured.

  7. Ecological, biological balances and conservation

    The scientific work within the activity ''ecological/biological balances and conservation'' is summarised in this report. The aims of the activity during its existence between 1992 and 1994 have been to: (i) arrange a workshop and publish the presentations on the environmental aspects of energy forest cultivations, (ii) perform joint scientific work together with the activity group on ''biological disposal of wastewaters and sludges'', that is closely related to environmental problems, and (iii) produce ecological guidelines concerning energy forestry, suitable for advisers and farmers dealing with bioenergy problems. The most important results from the workshop were the environmental benefits from energy forestry when compared with intensive agriculture and forestry. Energy forestry has positive influence on the carbon balances, nutrient recycling, and soil sustainability. The effects are also positive on the natural flora and fauna, which in most cases are enriched when compared with agricultural crops. From the joint efforts of the two activities the main result was a study tour, conference and workshop, concentrating on biological purification systems. The most promising system seems to be the vegetation filters of short rotation coppice. The report on ecological guidelines contains a number of ideas and recommendations for establishment, management, and harvesting of energy forests in an environmentally acceptable way. It also gives advice on how to locate the stands to minimise the risk of nutrient leakage from arable land. (Author)

  8. Differential force balances during levitation

    Todd, Paul

    The simplest arithmetic of inertial, buoyant, magnetic and electrokinetic levitation is explored in the context of a model living system with “acceleration-sensitive structures” in which motion, if allowed, produces a biological effect. The simple model is a finite-sized object enclosed within another finite-sized object suspended in an outer fluid (liquid or vapor) medium. The inner object has density and electrical and magnetic properties quantitatively different from those of the outer object and the medium. In inertial levitation (“weightlessness”) inertial accelerations are balanced, and the forces due to them are canceled in accordance with Newton’s third law. In the presence of inertial acceleration (gravity, centrifugal) motionlessness depends on a balance between the levitating force and the inertial force. If the inner and outer objects differ in density one or the other will be subjected to an unbalanced force when one object is levitated by any other force (buoyant, magnetic, electrokinetic). The requirements for motionlessness of the internal object in the presence of a levitating force are equality of density in the case of buoyant levitation, equality of magnetic susceptibility in the case of magnetic levitation, and equality of zeta potential and dielectric constant in the case of electrokinetic levitation. Examples of internal “acceleration-sensitive structures” are cellular organelles and the organs of advanced plants and animals. For these structures fundamental physical data are important in the interpretation of the effects of forces used for levitation.

  9. Mass balance assessment using GPS

    Hulbe, Christina L.

    1993-01-01

    Mass balance is an integral part of any comprehensive glaciological investigation. Unfortunately, it is hard to determine at remote locations where there is no fixed reference. The Global Positioning System (GPS) offers a solution. Simultaneous GPS observations at a known location and the remote field site, processed differentially, will accurately position the camp site. From there, a monument planted in the firn atop the ice can also be accurately positioned. Change in the monument's vertical position is a direct indicator of ice thickness change. Because the monument is not connected to the ice, its motion is due to both mass balance change and to the settling of firn as it densifies into ice. Observations of relative position change between the monument and anchors at various depths within the firn are used to remove the settling effect. An experiment to test this method has begun at Byrd Station on the West Antarctic Ice Sheet and the first epoch of observations was made. Analysis indicates that positioning errors will be very small. It appears likely that the largest errors involved with this technique will arise from ancillary data needed to determine firn settling.

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

    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

  11. Cell phone based balance trainer

    Lee Beom-Chan

    2012-02-01

    Full Text Available Abstract Background In their current laboratory-based form, existing vibrotactile sensory augmentation technologies that provide cues of body motion are impractical for home-based rehabilitation use due to their size, weight, complexity, calibration procedures, cost, and fragility. Methods We have designed and developed a cell phone based vibrotactile feedback system for potential use in balance rehabilitation training in clinical and home environments. It comprises an iPhone with an embedded tri-axial linear accelerometer, custom software to estimate body tilt, a "tactor bud" accessory that plugs into the headphone jack to provide vibrotactile cues of body tilt, and a battery. Five young healthy subjects (24 ± 2.8 yrs, 3 females and 2 males and four subjects with vestibular deficits (42.25 ± 13.5 yrs, 2 females and 2 males participated in a proof-of-concept study to evaluate the effectiveness of the system. Healthy subjects used the system with eyes closed during Romberg, semi-tandem Romberg, and tandem Romberg stances. Subjects with vestibular deficits used the system with both eyes-open and eyes-closed conditions during semi-tandem Romberg stance. Vibrotactile feedback was provided when the subject exceeded either an anterior-posterior (A/P or a medial-lateral (M/L body tilt threshold. Subjects were instructed to move away from the vibration. Results The system was capable of providing real-time vibrotactile cues that informed corrective postural responses. When feedback was available, both healthy subjects and those with vestibular deficits significantly reduced their A/P or M/L RMS sway (depending on the direction of feedback, had significantly smaller elliptical area fits to their sway trajectory, spent a significantly greater mean percentage time within the no feedback zone, and showed a significantly greater A/P or M/L mean power frequency. Conclusion The results suggest that the real-time feedback provided by this system can be used

  12. Single Switched Capacitor Battery Balancing System Enhancements

    Joeri van Mierlo

    2013-04-01

    Full Text Available Battery management systems (BMS are a key element in electric vehicle energy storage systems. The BMS performs several functions concerning to the battery system, its key task being balancing the battery cells. Battery cell unbalancing hampers electric vehicles’ performance, with differing individual cell voltages decreasing the battery pack capacity and cell lifetime, leading to the eventual failure of the total battery system. Quite a lot of cell balancing topologies have been proposed, such as shunt resistor, shuttling capacitor, inductor/transformer based and DC energy converters. The shuttling capacitor balancing systems in particular have not been subject to much research efforts however, due to their perceived low balancing speed and high cost. This paper tries to fill this gap by briefly discussing the shuttling capacitor cell balancing topologies, focusing on the single switched capacitor (SSC cell balancing and proposing a novel procedure to improve the SSC balancing system performance. This leads to a new control strategy for the SSC system that can decrease the balancing system size, cost, balancing time and that can improve the SSC balancing system efficiency.

  13. Balance and injury in elite Australian footballers.

    Hrysomallis, C; McLaughlin, P; Goodman, C

    2007-10-01

    This project measured pre-season balance ability and determined its relationship to knee and ankle ligament injuries during the season for professional Australian footballers. The balance test involved the players stepping onto a foam balance mat on top of a force plate and maintaining single limb balance. Throughout the playing season, injuries were monitored. The results from two hundred and ten players participating in this project were analysed. During the 2003 season, 8 % (17 out of 210) sustained a knee ligament injury and 10 % (21 out of 210) sustained an ankle ligament injury. Multivariate analysis revealed that pre-season balance ability was a significant independent predictor of ankle ligament injury. Players with low balance ability had at least twice as many ankle ligaments injuries as those with average or good balance ability. Balance ability was not a significant predictor of knee ligament injuries. The height of the players was the only significant independent predictor of knee ligament injuries. Low pre-season balance ability was associated with an increased risk of ankle ligament injury. A modifiable injury risk factor has been identified. Research is now required to determine the optimal training regime to enhance balance ability and whether this translates to a reduction in the incidence of ankle injuries. PMID:17373597

  14. Acid-base and ionic fluxes in rainbow trout (Oncorhynchus mykiss) during exposure to chloramine-T

    Powell, M.D.; Perry, S.F. [Department of Biology, University of Ottawa, 30 Marie Curie Ottawa, Ontario, K1N 6N5 (Canada)

    1998-09-01

    The effects of chloramine-T and its degradation products, sodium hypochlorite (NaOCl) and para-toluenesulphonamide (pTSA), on whole body acid-base and branchial and renal ion (Na{sup +}and Cl{sup -}) fluxes were examined in rainbow trout (Oncorhynchus mykiss). Exposure to chloramine-T (3.5 h, 18 mg l{sup -1}) resulted in increases in plasma total CO{sub 2} but no coincident rise in P{sub a}CO{sub 2} or reduction in blood pH. Exposure of fish to 2, 9 or 18 mg l{sup -1} chloramine-T (3.5 h duration) resulted in a reduction in net acid uptake suggesting the development of a metabolic alkalosis. Exposure to the chloramine-T breakdown product pTSA (dissolved in DMSO) resulted in increased net acid uptake (decreased acid excretion) suggesting a metabolic acidosis. Whole body ion fluxes demonstrated increases in the losses of both Na{sup +}and Cl{sup -} with chloramine-T, NaOCl and pTSA. However, the effect of DMSO alone could not be isolated. Confirmatory studies using fish in which the urinary bladder (to allow collection of urine) and dorsal aorta (to allow injection of [{sup 14}C]polyethylene glycol 4000 ([{sup 14}C]PEG), an extracellular fluid marker) were catheterised, revealed that changes in whole body ion fluxes during chloramine-T exposure could not be explained by increased renal efflux through urine flow, glomerular filtration or renal clearance. Branchial effluxes of [{sup 14}C]PEG were not significantly affected by chloramine-T exposure suggesting that the changes in whole body ionic fluxes were caused by transcellular rather than paracellular processes. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Site and chirality selective chemical modifications of boron nitride nanotubes (BNNTs) via Lewis acid-base interactions.

    Sundaram, Rajashabala; Scheiner, Steve; Roy, Ajit K; Kar, Tapas

    2015-02-01

    The pristine BNNTs contain both Lewis acid (boron) and Lewis base (nitrogen) centers at their surface. Interactions of ammonia and borane molecules, representatives of Lewis base and acid as adsorbates respectively, with matching sites at the surface of BNNTs, have been explored in the present DFT study. Adsorption energies suggest stronger chemisorption (about 15-20 kcal mol(-1)) of borane than ammonia (about 5-10 kcal mol(-1)) in both armchair (4,4) and zigzag (8,0) variants of the tube. NH3 favors (8,0) over the (4,4) tube, whereas BH3 exhibits the opposite preference, indicating some chirality dependence on acid-base interactions. A new feature of bonding is found in BH3/AlH3-BNNTs (at the edge site) complexes, where one hydrogen of the guest molecule is involved in three-center two-electron bonding, in addition to dative covalent bond (N: → B). This interaction causes a reversal of electron flow from borane/alane to BNNT, making the tube an electron acceptor, suggesting tailoring of electronic properties could be possible by varying strength of incoming Lewis acids. On the contrary, BNNTs always behave as electron acceptor in ammonia complexes. IR, XPS and NMR spectra show some characteristic features of complexes and can help experimentalists to identify not only structures of such complexes but also the location of the guest molecules and design second functionalizations. Interaction with several other neutral BF3, BCl3, BH2CH3 and ionic CH3(+) acids as well as amino group (CH3NH2 and NH2COOH) were also studied. The strongest interaction (>100 kcal mol(-1)) is found in BNNT-CH3(+) complexes and H-bonds are the only source of stability of NH2COOH-BNNT complexes. PMID:25559141

  16. Acid-base pH curves in vitro with mixtures of pure cultures of human oral microorganisms.

    Wijeyeweera, R L; Kleinberg, I

    1989-01-01

    Pure cultures of microorganisms commonly found in supragingival plaque were incubated alone and in combinations to determine the bacterial contribution to the pH-fall-pH-rise that is the central characteristic of the Stephan-curve pH change seen in plaque in vivo after brief exposure to a sugar solution. To avoid the complicating conditions of saliva flow and plaque diffusion, experiments were done with bacterial suspensions in incubations in vitro. In an initial experimental series where each microorganism was incubated only with glucose, all but a few produced the initial pH fall. Some also showed a subsequent small, sharp rise in the pH which then quickly levelled off; this was due to metabolism of endogenous substrate accumulated by most microorganisms during their growth in culture. When arginolytic and non-arginolytic bacteria were each then incubated with both glucose and arginine present (the glucose substrate to stimulate a pH fall and the arginine to stimulate a pH rise), the non-arginolytic gave a progressively more acidic pH response with progressive increase in the cell concentration, whereas the arginolytic bacteria produced a much smaller and variable pH decrease with similar cell concentration increase. Mixing pure cultures of either arginolytic or non-arginolytic bacteria gave acid-base pH responses similar to those of their respective pure cultures, whereas mixing arginolytic with non-arginolytic bacteria resulted in an approximate averaging of their different curves. The organisms present in highest proportion in a mixture had the greatest effects. The outcome of mixing the most numerous streptococcal and actinomyces species found normally in supragingival plaque indicated that the well-established difference in the acidity level of the Stephan pH response of caries-active and caries-inactive plaques could be due to differences in the proportions of their arginolytic and non-arginolytic members. PMID:2675801

  17. Energy-balance climate models

    North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

    1980-01-01

    An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

  18. A Generalized Detailed Balance Relation

    Ruelle, David

    2016-08-01

    Given a system M in a thermal bath we obtain a generalized detailed balance relation for the ratio r=π _τ (K→ J)/π _τ (J→ K) of the transition probabilities M:J→ K and M:K→ J in time τ . We assume an active bath, containing solute molecules in metastable states. These molecules may react with M and the transition J→ K occurs through different channels α involving different reactions with the bath. We find that r=sum p^α r^α , where p^α is the probability that channel α occurs, and r^α depends on the amount of heat (more precisely enthalpy) released to the bath in channel α.

  19. Relevance of balance measurement tools and balance training for fall prevention in older adults

    Majumi M. Noohu, MPTh

    2014-06-01

    Full Text Available Approximately one in three older people fall each year owing to gait/balance disorder/weakness, the second leading cause of falls in older adults. This review evaluates the capability of different balance measurement tools to predict falls in the elderly, which are used routinely for assessing balance impairment. Balance measurement tools reviewed are the Timed Up and Go test, Berg Balance Scale, Tinetti Performance Oriented Mobility Assessment, Functional Reach Test, Clinical Test of Sensory Integration for Balance, and the postural sway measurements or center of pressure. The effect of balance training on the postural control mechanism and its efficacy in fall prevention in older adults were also reviewed. The current evidence is not conclusive enough to favor existing balance measurement tools and balance training implemented for fall prevention in older adults.

  20. Milestones in gait, balance, and falling.

    Nutt, John G; Horak, Fay B; Bloem, Bastiaan R

    2011-05-01

    Gait, balance, and falls have become increasingly common topics of published articles in the Movement Disorders journal since its launch in 1986. This growth represents an increasing awareness of the importance of mobility to patients' quality of life. New methods have become available that allow for accurate measurement of many aspects for gait and balance. This has led to new concepts of understanding gait and balance disorders. Neuroimaging has begun to reveal the neural circuitry underlying gait and balance. The physiology and pathophysiology of balance and gait are beginning to tease out the many processes involved in mobility and how they may be disrupted by disease processes. With these advances, the old therapeutic nihilism that characterized the clinician's approach to falls and gait disorders is disappearing, as innovative physiotherapy, exercise, drugs, and deep brain stimulation are being employed for gait and balance disorders. PMID:21626560

  1. Balance Systems and the Variational Bicomplex

    Preston, Serge

    2011-07-01

    In this work we show that the systems of balance equations (balance systems) of continuum thermodynamics occupy a natural place in the variational bicomplex formalism. We apply the vertical homotopy decomposition to get a local splitting (in a convenient domain) of a general balance system as the sum of a Lagrangian part and a complemental ''pure non-Lagrangian'' balance system. In the case when derivatives of the dynamical fields do not enter the constitutive relations of the balance system, the ''pure non-Lagrangian'' systems coincide with the systems introduced by S. Godunov [Soviet Math. Dokl. 2 (1961), 947-948] and, later, asserted as the canonical hyperbolic form of balance systems in [Müller I., Ruggeri T., Rational extended thermodynamics, 2nd ed., Springer Tracts in Natural Philosophy, Vol. 37, Springer-Verlag, New York, 1998].

  2. Balance Systems and the Variational Bicomplex

    Serge Preston

    2011-07-01

    Full Text Available In this work we show that the systems of balance equations (balance systems of continuum thermodynamics occupy a natural place in the variational bicomplex formalism. We apply the vertical homotopy decomposition to get a local splitting (in a convenient domain of a general balance system as the sum of a Lagrangian part and a complemental ''pure non-Lagrangian'' balance system. In the case when derivatives of the dynamical fields do not enter the constitutive relations of the balance system, the ''pure non-Lagrangian'' systems coincide with the systems introduced by S. Godunov [Soviet Math. Dokl. 2 (1961, 947-948] and, later, asserted as the canonical hyperbolic form of balance systems in [Müller I., Ruggeri T., Rational extended thermodynamics, 2nd ed., Springer Tracts in Natural Philosophy, Vol. 37, Springer-Verlag, New York, 1998].

  3. Internal strain gage balances for cryogenic windtunnels

    Hufnagel, K.; Ewald, B.; Graewe, E.

    The five cryogenic wind-tunnel balances which were built and calibrated as part of the cryogenic balance program initiated in 1979 by the German Ministry of Research and Technology are described. Particular attention is given to factors affecting the calibration of cryogenic balances, such as the changes in the temperature and temperature gradients in the balance body caused by changes in the tunnel temperature. It is shown that it is possible to have a cryogenic wind-tunnel balance with the same accuracy and repeatability as a conventional balance. The effect of temperature gradients can be minimized by a new design of the axial-force element and an advanced calibration, and the zero shift can be reduced by matching procedures and calibration.

  4. The Balanced Scorecard: translating strategy into results

    POPA A. Simona

    2009-01-01

    In the paper it is shown that the Balanced Business Scorecard (BSC) allows a balance between financial and non financial objectives and performs a quantification of the dimensions of strategy in four areas - financial, customers, processes and potential. Moreover, the BSC provides feedback on internal processes and external outcomes in order to improve further the performance and results in terms of strategy. When the Balanced Scorecard is implemented effectively, can transform strategic plan...

  5. ANALYSIS FINANCIAL BALANCE AS BASE MANAGEMENT COMPANY

    Dragan Mihajlovic, Svetislav Stankovic, Milos Nikolic

    2015-01-01

    The financial position is determined by the state of financial balance, indebtedness, solvency, maintaining the real value of the capital and reproductive capacity. The company has a good financial position if financial balance ensures the safety of the maintenance of liquidity, if the debt provides full independence the company and good safety of its creditors. The financial balance assumes that the assets, which cannot be paid, by volume and time correspond to the scope and time to availabi...

  6. Water balance model for Kings Creek

    Wood, Eric F.

    1990-01-01

    Particular attention is given to the spatial variability that affects the representation of water balance at the catchment scale in the context of macroscale water-balance modeling. Remotely sensed data are employed for parameterization, and the resulting model is developed so that subgrid spatial variability is preserved and therefore influences the grid-scale fluxes of the model. The model permits the quantitative evaluation of the surface-atmospheric interactions related to the large-scale hydrologic water balance.

  7. The psychology of the nuclear balance

    The balance of military forces is meant to prevent war. But it is a very precarious balance, which becomes all the more dubious when the deterrent is no longer psychologically effective: when the country attacked is deterred from striking back with nuclear weapons. A unilateral disarmament above the overkill level would be possible without endangering the balance. It would improve the climate for mutual disarmament. (orig.)

  8. Flux-balance modelling of plant metabolism

    Lee James Sweetlove; R. George eRatcliffe

    2011-01-01

    Flux-balance modelling of plant metabolic networks provides an important complement to 13C-based metabolic flux analysis. Flux-balance modelling is a constraints-based approach in which steady-state fluxes in a metabolic network are predicted by using optimisation algorithms within an experimentally bounded solution space. In the last two years several flux-balance models of plant metabolism have been published including genome-scale models of Arabidopsis metabolism. In this review we conside...

  9. Controlling balance in an ensemble Kalman filter

    G. A. Gottwald

    2014-01-01

    We present a method to control unbalanced fast dynamics in an ensemble Kalman filter by introducing a weak constraint on the imbalance in a spatially sparse observational network. We show that the balance constraint produces significantly more balanced analyses than ensemble Kalman filters without balance constraints and than filters implementing incremental analysis updates (IAU). Furthermore, our filter with the weak constraint on imbalance produces good rms error statisti...

  10. Improving fluid balance monitoring on the wards

    Jeyapala, Sobanakumari; Gerth, Alice; Patel, Aarti; Syed, Nazia

    2015-01-01

    Clinical experience and nursing metrics have consistently identified poor documentation of fluid balance monitoring at Milton Keynes University Hospital, compromising patient safety and quality of care. This project aimed to increase the percentage of fluid balance charts correctly completed on the wards. Three areas for improvement were identified: understanding the importance of good fluid balance monitoring, correct identification of patients requiring monitoring, and ease of completion of...

  11. Reanalysing glacier mass balance measurement series

    Zemp, M.; E. Thibert; Huss, M.; Stumm, D.; Rolstad Denby, C.; Nuth, C.; S. U. Nussbaumer; G. Moholdt; A. Mercer; Mayer, C.; Joerg, P. C.; P. Jansson; B. Hynek; Fischer, A.; Escher-Vetter, H.

    2013-01-01

    Glacier-wide mass balance has been measured for more than sixty years and is widely used as an indicator of climate change and to assess the glacier contribution to runoff and sea level rise. Until recently, comprehensive uncertainty assessments have rarely been carried out and mass balance data have often been applied using rough error estimation or without consideration of errors. In this study, we propose a framework for reanalysing glacier mass balance series that includes conceptual and ...

  12. Common muscle synergies for balance and walking

    Chvatal, Stacie A.; Ting, Lena H.

    2013-01-01

    Little is known about the integration of neural mechanisms for balance and locomotion. Muscle synergies have been studied independently in standing balance and walking, but not compared. Here, we hypothesized that reactive balance and walking are mediated by a common set of lower-limb muscle synergies. In humans, we examined muscle activity during multidirectional support-surface perturbations during standing and walking, as well as unperturbed walking at two speeds. We show that most muscle ...

  13. Reframing Our Pursuit of Life Balance

    Fuentes, David G.; Ogden, Rachel R.; Ryan-Haddad, Ann; Strang, Aimee F.

    2015-01-01

    During our time in the 2013 Academic Leadership Fellows Program, we explored what it takes to achieve life balance through a framework presented in a Harvard Business Review article. In this Statement, we describe 5 different areas from the article that provide infrastructure for reflecting on how we have learned to approach life balance in academia. We also provide brief messages based on this reading and others to help academics’ pursuit of life balance.

  14. Reframing our pursuit of life balance.

    Fuentes, David G; Ogden, Rachel R; Ryan-Haddad, Ann; Strang, Aimee F

    2015-04-25

    During our time in the 2013 Academic Leadership Fellows Program, we explored what it takes to achieve life balance through a framework presented in a Harvard Business Review article. In this Statement, we describe 5 different areas from the article that provide infrastructure for reflecting on how we have learned to approach life balance in academia. We also provide brief messages based on this reading and others to help academics' pursuit of life balance. PMID:25995509

  15. Competing values in healthcare: balancing the (un)balanced scorecard.

    Wicks, Angela M; St Clair, Lynda

    2007-01-01

    Facing a complex environment driven by two decades of dramatic change, healthcare organizations are adopting new strategic frameworks such as the Balanced Scorecard (BSC) to evaluate performance (Kaplan and Norton 1992). The BSC was not originally developed as a performance management tool, however. Rather, it was designed as a tool to communicate strategy and, as such, provides little guidance when actual outcomes fall short of desired outcomes. In addition, although the BSC is an improvement over exclusively financial measures, it has three conceptual limitations that are especially problematic for evaluating healthcare organizations: (1) it underemphasizes the employee perspective, (2) it is founded on a control-based management philosophy, and (3) it emphasizes making trade-offs. To address these limitations, we propose using the Competing Values Framework (CVF), a theoretically grounded, comprehensive approach to understanding and improving organizational and managerial performance by focusing on four action imperatives: competing, controlling, collaborating, and creating. The CVF pays particular attention to the employee perspective, is consistent with a commitment-based management philosophy, and emphasizes transcending apparent paradoxes to identify win-win solutions. Rather than focusing on customer satisfaction or employee satisfaction, the CVF looks for ways to satisfy customers and employees while still addressing financial constraints and growth opportunities. The CVF also can be used to assess both the culture of the organization and the competencies of individual managers, thereby providing a clear link between strategy and implementation. PMID:17933187

  16. Balancing energy strategies in electricity portfolio management

    Traditional management of electricity portfolios is focused on the day-ahead market and futures of longer maturity. Within limits, market participants can however also resort to the balancing energy market to close their positions. In this paper, we determine strategic positions in the balancing energy market and identify corresponding economic incentives in an analysis of the German balancing energy demand. We find that those strategies allow an economically optimal starting point for real-time balancing and create a marketplace for flexible capacity that is more open than alternative marketplaces. The strategies we proffer in this paper we believe will contribute to an effective functioning of the electricity market. (author)

  17. Energy balance in the transformation centers

    Carbon balance is an important instrument to identify the emission sources of greenhouse effect gases. Since energy use and transformation are fundamental for increasing these gases in the atmosphere, the carbon balance survey can be used to identify sectors and fuels to which priority should be given regarding emissions mitigation. In the case of transformation centers (installations where primary or secondary sources are converted into sub-products or other energy form) the balance indicated some problems regarding the Brazilian inventory calculation. Problems concerning the National Energy Balance data used here were also identified. (author)

  18. A Load Balancing Technique for Wireless LANs

    K.Vaitheki; S.BalaBaskar

    2011-01-01

    Throughput maximization in a network is one of the major key challenges in wireless LANs (WLANs) and it could be achieved when the load of access points (APs) is balanced. The AP load in WLANs is very often found to be uneven. To overcome such imbalance of load, a load balancing technique have been proposed. The load balancing techniques commonly require proprietary software or hardware at the user side for controlling the user-AP association. A new load balancing technique by controlling the...

  19. Balancing guava nutrition with liming and fertilization

    Amanda Hernandes

    2012-12-01

    Full Text Available Guava response to liming and fertilization can be monitored by tissue testing. Tissue nutrient signature is often diagnosed against nutrient concentration standards. However, this approach has been criticized for not considering nutrient interactions and to generate numerical biases as a result of data redundancy, scale dependency and non-normal distribution. Techniques of compositional data analysis can control those biases by balancing groups of nutrients, such as those involved in liming and fertilization. The sequentially arranged and orthonormal isometric log ratios (ilr or balances avoid numerical bias inherent to compositional data. The objectives were to relate tissue nutrient balances with the production of "Paluma" guava orchards differentially limed and fertilized, and to adjust the current patterns of nutrient balance with the range of more productive guava trees. It was conducted one experiment of 7-yr of liming and three experiments of 3-yr with N, P and K trials in 'Paluma' orchards on an Oxisol. Plant N, P, K, Ca and Mg were monitored yearly. It was selected the [N, P, K | Ca, Mg], [N, P | K], [N | P] and [Ca | Mg] balances to set apart the effects of liming (Ca-Mg and fertilizers (N-K on macronutrient balances. Liming largely influenced nutrient balances of guava in the Oxisol while fertilization was less influential. The large range of guava yields and nutrient balances allowed defining balance ranges and comparing them with the critical ranges of nutrient concentration values currently used in Brazil and combined into ilr coordinates.

  20. Rare earths and the balance problem

    Binnemans, Koen; Jones , Peter Tom

    2015-01-01

    Maintaining the balance between the demand by the economic markets and the natural abundance of the rare-earth elements (REEs) in ores constitutes a major challenge for manufacturers of these elements. This is the so-called balance problem (or balancing problem). The ideal situation is a perfect match between the demand and (production) supply of REEs, so that there are no surpluses of any of the REEs. The balance problem implicates that the rare-earth industry has to either find new applicat...

  1. Mass balance gradients and climatic change

    Oerlemans, J.; Hoogendoorn, N.C.

    1989-01-01

    It is generally assumed that the mass-balance gradient on glaciers is more or less conserved under climatic change. In studies of the dynamic response of glaciers to climatic change, one of the following assumptions is normally made: (i) the mass-balance perturbation is independent of altitude or (ii) the mass-balance profile does not change - it simply shifts up and down. Observational evidence for such an approach is not convincing; on some glaciers the inter-annual changes in mass balance ...

  2. Mechanical Behavior and Thermal Stability of Acid-Base Phosphate Cements and Composites Fabricated at Ambient Temperature

    Colorado Lopera, Henry Alonso

    This dissertation presents the study of the mechanical behavior and thermal stability of acid-base phosphate cements (PCs) and composites fabricated at ambient temperature. These materials are also known as chemically bonded phosphate ceramics (CBPCs). Among other advantages of using PCs when compared with traditional cements are the better mechanical properties (compressive and flexural strength), lower density, ultra-fast (controllable) setting time, controllable pH, and an environmentally benign process. Several PCs based on wollastonite and calcium and alumino phosphates after thermal exposure up to 1000°C have been investigated. First, the thermo-mechanical and chemical stability of wollastonite-based PC (Wo-PC) exposed to temperatures up to 1000°C in air environment were studied. The effects of processing conditions on the curing and shrinkage of the wollastonite-based PC were studied. The chemical reactions and phase transformations during the fabrication and during the thermal exposure are analyzed in detail using scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermo-gravimetric analysis (TGA Then, the thermo-mechanical and chemical stability of glass, carbon and basalt fiber reinforced Wo-PC composites, were studied using SEM, XRD, TGA. The flexural strength and Weibull statistics were analyzed. A significant strength degradation in the composites were found after the thermal exposure at elevated temperatures due to the interdifusion and chemical reactions across the fibers and the matrix at temperatures over 600°C. To overcome this barrier, we have developed a new PC based on calcium and alumino-phosphates (Ca-Al PCs). The Ca-Al PCs were studied in detail using SEM, XRD, TGA, curing, shrinkage, Weibull statistics, and compression tests. Our study has confirmed that this new composite material is chemically and mechanically stable at temperatures up to 1000°C. Moreover, the compression strength increases after exposure to 1000

  3. Acid-base equilibria and dynamics in sodium dodecyl sulfate micelles: geminate recombination and effect of charge stabilization.

    Freitas, Adilson A; Paulo, Luisa; Maçanita, Antonio L; Quina, Frank H

    2006-09-12

    The synthetic flavylium salt 4-carboxy-7-hydroxy-4'-methoxyflavylium chloride (CHMF) exhibits two acid-base equilibria in the range of pH 1-8 in both aqueous and micellar sodium dodecyl sulfate (SDS) solutions. The values of pK(a1) and pK(a2) for the cation-zwitterion (AH(2)(+) Z + H(+)) and the zwitterion-base (Z A(-) + H(+)) equilibria increase from 0.73 and 4.84 in water to 2.77 and 5.64 in SDS micelles, respectively. The kinetic study of the Z A(-) + H(+) ground-state reactions in SDS points to the diffusion-controlled protonation of A(-) in the aqueous phase (k(p2w) = 4.2 x 10(10) M(-)(1) s(-)(1)) and in the micelle (k(p2m) = 2.3 x 10(11) M(-)(1) s(-)(1)). The deprotonation rate of Z did not significantly change upon going from water (k(d2) = 6.3 x 10(5) s(-)(1)) to SDS (k(d2) = 5.2 x 10(5) s(-)(1)), in contrast with the behavior of ordinary cationic flavylium salts, for which k(d2) strongly decreases in SDS micelles. These results suggest that deprotonation of the zwitterionic acid is not substantially perturbed by the micellar charge. Electronic excitation of the Z form of CHMF induces fast adiabatic deprotonation of the hydroxyl group of Z() (2.9 x 10(10) s(-)(1) in water and 8.4 x 10(9) s(-)(1) in 0.1 M SDS), followed by geminate recombination on the picosecond time scale. Interestingly, while recombination in water (k(rec) = 1.7 x 10(9) s(-)(1)) occurs preferentially at the carboxylate group, at the SDS micelle surface, recombination (k(rec) = 9.2 x 10(9) s(-)(1)) occurs at the hydroxyl group. The important conclusion is that proton mobility at the SDS micelle surface is substantially reduced with respect to the mobility in water, which implies that geminate recombination should be a general phenomenon in SDS micelles. PMID:16952232

  4. Application of Chybeshev Polynomials in Factorizations of Balancing and Lucas-Balancing Numbers

    Prasanta Kumar Ray

    2012-01-01

    Full Text Available In this paper, with the help of orthogonal polynomial especially Chybeshev polynomials of first and second kind, number theory and linear algebra intertwined to yield factorization of the balancing and Lucas-balancing numbers.

  5. Application of Chybeshev Polynomials in Factorizations of Balancing and Lucas-Balancing Numbers

    Prasanta Kumar Ray

    2012-01-01

    In this paper, with the help of orthogonal polynomial especially Chybeshev polynomials of first and second kind, number theory and linear algebra intertwined to yield factorization of the balancing and Lucas-balancing numbers.

  6. Energy Balance and Physical Activity

    2001-01-01

    The prevalence of obesity is increasing in most parts of theworld and becoming one of the major global public health problems. Although the components of energy balance have not been adequately estimated over time, available evidence suggests that the increase in obesity is the result of reduced physical activity. Increases in physical activity have been shown to be strongly associated with improving physical fitness and body composition, with probably a positive effect on resting metabolic rate. The Surgeon General's Report on Physical Activity and Health advocates that 30 min of regular, moderate-intensity physical activity is associated with decreases in the risk of chronic diseases and may contribute to quality of life. However, the small changes that contribute 10 min for 3 times a day for aerobic training, or one set instead of three sets of repetitions on resistance training will provide individuals with health benefits. Indeed, nutrition and physical activity should be considered an integral part of fitness and good health, and should be encouraged in all age groups, particularly early in life. The question is no longer centered around the health benefit of increasing physical activity, but rather creating self awareness and behavior changes in individuals. Hence, effective intervention programs are needed that foster long term changes in physical activity. Among various interventions, the Nutrifit program was recently conducted in Thailand and found to improve health related fitness in children. The development of more effective interventions and approaches is a major challenge in this field today.

  7. Vulnerability of pension fund balances

    Ólafur Ísleifsson

    2012-12-01

    Full Text Available Although the Icelandic general labour market pension funds are built on the proviso that pension schemes are fully funded these funds are still grappling with the devastating financial effects of the 2008 economic collapse that rendered most of them in a significant actuarial deficit. The public sector pension funds are based on an employer guarantee that makes up for any lack of funding that historically has been quite significant. We identify the relatively high actuarial discount rate and increasing longevity as two factors that add to the vulnerability of the Icelandic pension system. We present a stochastic model in order to obtain reasonably sound estimates of the effect of revising such key parameters of the actuarial assessments of the pension funds and thus obtain a view of the viability of the Icelandic pension system when confronted with the potential necessity of such parameter shifts. We present results of stochastic simulations of this models made to assess effects of changes in these major financial and demographic assumptions in actuarial evaluations of pension fund balances. Our results suggest that the Icelandic pension funds may be significantly less well funded than is generally perceived.

  8. Aposematism: balancing salience and camouflage.

    Barnett, James B; Scott-Samuel, Nicholas E; Cuthill, Innes C

    2016-08-01

    Aposematic signals are often characterized by high conspicuousness. Larger and brighter signals reinforce avoidance learning, distinguish defended from palatable prey and are more easily memorized by predators. Conspicuous signalling, however, has costs: encounter rates with naive, specialized or nutritionally stressed predators are likely to increase. It has been suggested that intermediate levels of aposematic conspicuousness can evolve to balance deterrence and detectability, especially for moderately defended species. The effectiveness of such signals, however, has not yet been experimentally tested under field conditions. We used dough caterpillar-like baits to test whether reduced levels of aposematic conspicuousness can have survival benefits when predated by wild birds in natural conditions. Our results suggest that, when controlling for the number and intensity of internal contrast boundaries (stripes), a reduced-conspicuousness aposematic pattern can have a survival advantage over more conspicuous signals, as well as cryptic colours. Furthermore, we find a survival benefit from the addition of internal contrast for both high and low levels of conspicuousness. This adds ecological validity to evolutionary models of aposematic saliency and the evolution of honest signalling. PMID:27484645

  9. Integral torque balance in tokamaks

    The study is aimed at clarifying the balance between the sinks and sources in the problem of intrinsic plasma rotation in tokamaks reviewed recently by deGrassie (2009 Plasma Phys. Control. Fusion 51 124047). The integral torque on the toroidal plasma is calculated analytically using the most general magnetohydrodynamic (MHD) plasma model taking account of plasma anisotropy and viscosity. The contributions due to several mechanisms are separated and compared. It is shown that some of them, though, possibly, important in establishing the rotation velocity profile in the plasma, may give small input into the integral torque, but an important contribution can come from the magnetic field breaking the axial symmetry of the configuration. In tokamaks, this can be the error field, the toroidal field ripple or the magnetic perturbation created by the correction coils in the dedicated experiments. The estimates for the error-field-induced electromagnetic torque show that the amplitude of this torque is comparable to the typical values of torques introduced into the plasma by neutral beam injection. The obtained relations allow us to quantify the effect that can be produced by the existing correction coils in tokamaks on the plasma rotation, which can be used in experiments to study the origin and physics of intrinsic rotation in tokamaks. Several problems are proposed for theoretical studies and experimental tests.

  10. Comparative Analysis of the Properties of Acid-Base Indicator of Rose (Rosa setigera), Allamanda (Allamanda cathartica), and Hibiscus (Hibiscus rosa-sinensis) Flowers

    Okoduwa, Stanley I. R.; Mbora, Lovina O.; Matthew E. Adu; Adeyi, Ameh A.

    2015-01-01

    The need to develop effective alternative for synthetic indicators is the demand of present-day chemistry. The acid-base indicator properties of Rose (Rosa setigera), Allamanda (Allamanda cathartica), and Hibiscus (Hibiscus rosa-sinensis) flowers were examined. Colour pigments were extracted from the flowers via cold and solvent extraction using soxhlet extractor. The pH value of the extracts with wavelengths of absorption was determined using ultraviolet spectrophotometer. From the results o...

  11. CHEMOTHERAPEUTIC POLYMERS ⅩⅩⅢ SYNTHESIS AND ANTITUMOR ACTIVITY OF POLYPHOSPHATES CONTAINING BOTH NUCLEIC ACID BASE AND PHOSPHONOACETIC ACID ETHYL ESTER

    ZHUO Renxi; LIU Zhenghua; LI Li

    1989-01-01

    Eight new polyphosphates containing both nucleic acid base and phosphonoacetic acid ethyl ester were synthesized by the polycondensation of P, P- dichloride of phosphonoacetic acid ethyl ester with 1, 3-dihydroxyalkyl - 5 - fluorouracil, 1,3 - dihydroxyalkyl - uracil and 1, 3 - dihydroxyalkylthymine. These polyphosphates were tested against Ehrlich Ascites Carcinoma in mice. Polymer Ⅱa and Ⅱc exhibited excellent antitumor activity. Ⅱc also showed lower toxicity.

  12. Acid-base and biochemical stabilization and quality of recovery in male cats with urethral obstruction and anesthetized with propofol or a combination of ketamine and diazepam

    Freitas, Gabrielle C.; Monteiro Carvalho Mori da Cunha, Marina G.; Gomes, Kleber; Monteiro Carvalho Mori da Cunha, João P.; Togni, Monique; Pippi, Ney L.; Carregaro, Adriano B

    2012-01-01

    This study compared acid-base and biochemical changes and quality of recovery in male cats with experimentally induced urethral obstruction and anesthetized with either propofol or a combination of ketamine and diazepam for urethral catheterization. Ten male cats with urethral obstruction were enrolled for urethral catheterization and anesthetized with either ketamine-diazepam (KD) or propofol (P). Lactated Ringer’s solution was administered by intravenous (IV) beginning 15 min before and con...

  13. Design, synthesis, and evaluation of hydroxamic acid-based molecular probes for in vivo imaging of histone deacetylase (HDAC) in brain

    Hooker, Jacob M.; Wang, Changning; Eessalu, Thomas E; Barth, Vanessa N.; Mitch, Charles H.; Wagner, Florence F.; Hong, Yijia; Neelamegam, Ramesh; Schroeder, Frederick A.; Holson, Edward B.; Haggarty, Stephen John

    2013-01-01

    Hydroxamic acid-based histone deacetylase inhibitors (HDACis) are a class of molecules with therapeutic potential currently reflected in the use of suberoylanilide hydroxamic acid (SAHA; Vorinostat) to treat cutaneous T-cell lymphomas (CTCL). HDACis may have utility beyond cancer therapy, as preclinical studies have ascribed HDAC inhibition as beneficial in areas such as heart disease, diabetes, depression, neurodegeneration, and other disorders of the central nervous system (CNS). However, l...

  14. Comparison of Dynamic Balance in Collegiate Field Hockey and Football Players Using Star Excursion Balance Test

    Bhat, Rashi; Moiz, Jamal Ali

    2013-01-01

    Purpose The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. Methods A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45° increments. The subjects were instruct...

  15. Blood gas analysis, anion gap, and strong ion difference in horses treated with polyethylene glycol balanced solution (PEG 3350 or enteral and parenteral electrolyte solutions

    Cláudio Luís Nina Gomes

    2014-06-01

    Full Text Available Large volumes of different electrolytes solutions are commonly used for ingesta hydration in horses with large colon impaction, but little is known about their consequences to blood acid-base balance. To evaluate the effects of PEG 3350 or enteral and parenteral electrolyte solutions on the blood gas analysis, anion gap and strong ion difference, five adult female horses were used in a 5x5 latin square design. The animals were divided in five groups and distributed to each of the following treatments: NaCl (0.9% sodium chloride solution; EES (enteral electrolyte solution, EES+LR (EES plus lactated Ringer's solution; PEG (balanced solution with PEG 3350 and PEG+LR (PEG plus lactated Ringer's solution. Treatments PEG or PEG + LR did not change or promoted minimal changes, while the EES caused a slight decrease in pH, but its association with lactated Ringer's solution induced increase in AG and SID values, as well as caused hypernatremia. In turn, the treatment NaCl generated metabolic acidosis. PEG 3350 did not alter the acid-base balance. Despite it's slight acidifying effect, the enteral electrolyte solution (EES did not cause clinically relevant changes.

  16. Gait and balance disorders in older adults.

    Salzman, Brooke

    2010-07-01

    Gait and balance disorders are common in older adults and are a major cause of falls in this population. They are associated with increased morbidity and mortality, as well as reduced level of function. Common causes include arthritis and orthostatic hypotension; however, most gait and balance disorders involve multiple contributing factors. Most changes in gait are related to underlying medical conditions and should not be considered an inevitable consequence of aging. Physicians caring for older patients should ask at least annually about falls, and should ask about or examine for difficulties with gait and balance at least once. For older adults who report a fall, physicians should ask about difficulties with gait and balance, and should observe for any gait or balance dysfunctions. The Timed Up and Go test is a fast and reliable diagnostic tool. Persons who have difficulty or demonstrate unsteadiness performing the Timed Up and Go test require further assessment, usually with a physical therapist, to help elucidate gait impairments and related functional limitations. The most effective strategy for falls prevention involves a multifactorial evaluation followed by targeted interventions for identified contributing factors. Evidence on the effectiveness of interventions for gait and balance disorders is limited because of the lack of standardized outcome measures determining gait and balance abilities. However, effective options for patients with gait and balance disorders include exercise and physical therapy. PMID:20590073

  17. Balance velocities of the Greenland ice sheet

    Joughin, I.; Fahnestock, M.; Ekholm, Simon; Kwok, R.

    1997-01-01

    We present a map of balance velocities for the Greenland ice sheet. The resolution of the underlying DEM, which was derived primarily from radar altimetery data, yields far greater detail than earlier balance velocity estimates for Greenland. The velocity contours reveal in striking detail the...

  18. Newton's Third Law on a Scale Balance

    Nopparatjamjomras, Suchai; Panijpan, Bhinyo; Huntula, Jiradawan

    2009-01-01

    We propose a series of experiments involving balance readings of an object naturally floating or forced to be partially or fully immersed in water contained in a beaker sitting on an electronic scale balance. Students were asked to predict, observe and explain each case. The teacher facilitated the learning by asking probing questions, giving…

  19. Balancing energy in the German market design

    Möller, Christoph

    2010-01-01

    Among electricity marketplaces balancing energy takes a central role in mediating the supply and demand equilibrium. This thesis analyzes strategies employed in the balancing energy market, as well as their implications for other marketplaces in the setting of the German electricity market.

  20. Energy balance in solid state fermentation processes

    Rodriguez, L.J.A.; Torres, A.; Echevarria, J.; Saura, G. (Instituto Cubano de Investigaciones de los Derivados de la Cana de Azucar (ICIDCA), La Habana (Cuba))

    1991-01-01

    It was applied a macroscopic energy balance to a solid state fermentation process and an electron balance in order to estimate the temperature and the heat evolved in the process. There were employed several equations that describe the development of the system and offer the possibility to design or control such fermentations. (orig.).

  1. On the Mass Balance of Asphaltene Precipitation

    Andersen, Simon Ivar; Lira-Galeana, C.; Stenby, Erling Halfdan

    2001-01-01

    In the evaluation of experimental data as well as in calculation of phase equilibria the necessity of the application of mass balances is obvious. In the case of asphaltenes the colloidal nature of these compounds may highly affect the mass balance. In the present paper several experiments are pe...

  2. The Global Challenge: A Matter of Balance.

    Mulford, Bill

    2002-01-01

    Argues that global challenge created by the pressure for change requires educators to understand the balance between continuity and constant change dependence and independence, individualism and community, homogeneity and heterogeneity. To achieve balanced learning and development, education should place greater emphasis on continuity,…

  3. 14 CFR 29.659 - Mass balance.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Mass balance. 29.659 Section 29.659... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.659 Mass balance. (a) The rotor... flutter at any speed up to the maximum forward speed. (b) The structural integrity of the mass...

  4. 14 CFR 27.659 - Mass balance.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Mass balance. 27.659 Section 27.659... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.659 Mass balance. (a) The rotors... flutter at any speed up to the maximum forward speed. (b) The structural integrity of the mass...

  5. 14 CFR 23.659 - Mass balance.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Mass balance. 23.659 Section 23.659 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Surfaces § 23.659 Mass balance. The supporting structure and the attachment of concentrated mass...

  6. Driving Improvement with a Balanced Scorecard

    Cowart, Scott K.

    2010-01-01

    This article describes how a school district's use of a transparent tool coalesced support for systemic improvement. The author was looking for a way to push improvement in his 4,000-student school system when he discovered the balanced scorecard, a strategic tool for performance management. The author details how the balanced scorecard helped him…

  7. Balancing with the Brain in Mind

    Stevens-Smith, Deborah

    2006-01-01

    In this article, the author states that it's important for physical educators to understand the connection between balancing and learning. Since, balancing activities provide a link between physical education and the classroom that can enhance both academic learning and physical skill development. They need to be aware of the tremendous impact…

  8. Balanced Scorecard as Part of Performance Measurement

    Petru Balogh

    2009-01-01

    The Balanced Scorecard has become one of the most popular and successful instrument for managing the organizations’ performance. This article sets the place of the balanced scorecard within the performance measurement system within the organizatin and presents, as an example, a way of implementing this method and establishing a composite index of performance.

  9. Brazilian energy balance 2008 - year 2007

    The Brazilian energy balance - BEB - is divided into eight chapters and eleven annexes, whose contents are as follow: chapter 1 - energy analysis and aggregated data; chapter 2 - energy supply and demand by source; chapter 3 - energy consumption by sector; chapter 4 - energy imports and exports; chapter 5 - balance of transformation centers; chapter 6 - energy resources and reserves; chapter 7 - energy and socioeconomics; chapter 8 - state energy data; annex I - installed capacity; annex II - self-generation of electricity; annex III - world energy data; annex IV - world energy evolution; annex V - useful energy balance; annex VI - general structure of the BEN; annex VII - treatment of information; annex VIII - units; annex IX - conversion factors; annex X - consolidated energy balances 1970/2007; annex XI - energy balance 2007. (author)

  10. Design Strategies for CeO2-MoO3 Catalysts for DeNOx and Hg(0) Oxidation in the Presence of HCl: The Significance of the Surface Acid-Base Properties.

    Chang, Huazhen; Wu, Qingru; Zhang, Tao; Li, Mingguan; Sun, Xiaoxu; Li, Junhua; Duan, Lei; Hao, Jiming

    2015-10-20

    A series of CeMoOx catalysts with different surface Ce/Mo ratios was synthesized by a coprecipitation method via changing precipitation pH value. The surface basicity on selective catalytic reduction (SCR) catalysts (CeMoOx and VMo/Ti) was characterized and correlated to the durability and activity of catalyst for simultaneous elimination of NOx and Hg(0). The pH value in the preparation process affected the surface concentrations of Ce and Mo, the Brunauer-Emmett-Teller (BET) specific surface area, and the acid-base properties over the CeMoOx catalysts. The O 1s X-ray photoelectron spectroscopy (XPS) spectra and CO2-temperature programmed desorption (TPD) suggested that the surface basicity increased as the pH value increased. The existence of strong basic sites contributed to the deactivation effect of HCl over the VMo/Ti and CeMoOx catalysts prepared at pH = 12. For the CeMoOx catalysts prepared at pH = 9 and 6, the appearance of surface molybdena species replaced the surface -OH, and the existence of appropriate medium-strength basic sites contributed to their resistance to HCl poisoning in the SCR reaction. Moreover, these sites facilitated the adsorption and activation of HCl and enhanced Hg(0) oxidation. On the other hand, the inhibitory effect of NH3 on Hg(0) oxidation was correlated with the competitive adsorption of NH3 and Hg(0) on acidic surface sites. Therefore, acidic surface sites may play an important role in Hg(0) adsorption. The characterization and balance of basicity and acidity of an SCR catalyst is believed to be helpful in preventing deactivation by acid gas in the SCR reaction and simultaneous Hg(0) oxidation. PMID:26421943

  11. Balancing Public and Private Regulation

    Martijn Scheltema

    2016-01-01

    an effective grievance mechanism, provide sufficient means for monitoring and enforcement and contribute to a more balanced risk attribution between producers and (ultimate buyers.

  12. Energy Balance and Physical Activity

    KALLAYAKIJBOONCHOO

    2001-01-01

    The prevalence of obesity is increasing in most parts of the world and becoming one of the major global public health problems.Although the components of energy balance have not been adequately estimated over time,available evidence suggests that the increase in obesity is the result of reduced physical activity.Increases in physical activity have been showen to be strongly associated with improving physical fitness and body composition,with probably a positive effect on resting metabolic rate.The Surgeon General's Report on physical Activity and Health advocates that 30 min of regular,moderate-intensity physical activity is associated with decreases in the risk of chronic diseases and may contribute to quality of life.However,the small changes that contribute 10 min for 3 times a day for 3 times a day for aerobic training,or one set instead of three sets of repetitions on resistance training will provide individuals training,or one set instead of three sets of repetitions on resistance training will provide individuals with health benefits.Indeed,nutrition and physical activity should be considered an integral part of fitness and good health,and should be encouraged in all age groups,particularly early in life,The question is no longer centerd around the health benefit of increasing physical activity,but rather creating self awareness and behavior changes in individuals,Hence,effective intervention programs are needed that foster long term changes in physical activity.Among various interventions,the Nutrifit program was recently conducted in Thailand and found to improve health related fitness in children,The development of more effective interventions and approaches is a major challege in this field today.

  13. Mass-balance parameters derived from a synthetic network of mass-balance glaciers

    Machguth, Horst; Haeberli, Wilfried; Paul, Frank

    2012-01-01

    Glacier mass-balance parameters such as the equilibrium-line altitude (ELA) play an important role when working with large glacier samples. While the number of observational mass-balance series to derive such parameters is limited, more and more modeled data are becoming available. Here we explore the possibilities of analyzing such ‘synthetic’ mass-balance data with respect to mass-balance parameters. A simplified energy-balance model is driven by bias-corrected regional climate model output...

  14. Introduction To Application Server Load Balancer

    Prof. Pamukumar Swamy

    2012-02-01

    Full Text Available Now a day’s, everything is going online. And most of the work is done on internet. So, web applications plays vital role on internet to provide 24*7 services to customers. When application becomes popular, traffic to that is also in a state of growing. For availability, scalability, performances boosting more and more servers are required. Load balancing is a key issue in these types of large scale situation. Load balancing is to achieve optimal resource utilization, maximize throughput, minimize response time, and avoid overload. In many scenarios, however, it’s not simply a matter of distributing traffic equally across many servers once deploys; other factors can come into play. Here we studied different load balancing strategies, algorithms, methods and investigate the comparative behavior of load balancing with different parameters. The growing autonomy of servers’ significantly deteriorates the performance of traditional load-balancing so; idea is to implement application load balancer by using Dynamic load balancing method.

  15. Brazilian energy balance 2002: calendar year 2001

    The Brazilian Energy Balance 2002, based on 2001 data, contains the information related to the supply and consumption of the primary and secondary energy sources, provided by data and information of responsible sectors. This version presents important differences in relation to the previous editions, new technical concepts were introduced for the treatment of calorific powers of energy sources in the composition and consolidation of data, and also in the structure of its contents. The Balance 2002 was structured in the same way of the last edition, divided in 8 chapters, as follows: summary of the relevant indicators of 2001 and consolidated data of production, consumption and external dependence on energy, and also the sectorial composition of the consumption of the different groups of energy sources - period 1970/2001; energy supply and demand by source - 1986/2001; energy consumption by sector - 1986/2001; energy foreign trading - 1986/2001; transformation centers balances - 1986/2001; energy resources and reserves - 1973/2001; energy and socio-economy - 1986/2001; regional parameters and appendices including: installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances - 1970/2001,in the 'kcal' unit, calculated in PCI- Inferior Calorific Power. This new model has the intention to approximate the Brazilian Energy Balance to the international methodologies, mainly to the OECD balances

  16. Balance of attraction and repulsion in nucleic-acid base stacking: CCSD(T)/complete-basis-set-limit calculations on uracil dimer and a comparison with the force-field description

    Morgado, C.A.; Jurečka, P.; Svozil, Daniel; Hobza, Pavel; Šponer, Jiří

    2009-01-01

    Roč. 5, č. 6 (2009), s. 1524-1544. ISSN 1549-9618 R&D Projects: GA AV ČR(CZ) IAA400040802; GA AV ČR(CZ) IAA400550701; GA MŠk(CZ) LC06030 Grant ostatní: GA ČR(CZ) GA203/09/1476 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702; CEZ:AV0Z40550506 Keywords : quantum chemical calculations * nucleic acids * force field Subject RIV: BO - Biophysics Impact factor: 4.804, year: 2009

  17. Effects of Sulfur-coating from Sulfur-coated Fertilizer on Acid-base Balance in Brown Soil%控释肥硫膜对棕壤酸碱平衡体系的影响

    张庆富; 张民; 宗晓庆; 颜晓

    2010-01-01

    研究了控释肥硫膜对棕壤酸碱平衡体系的影响,探讨硫包膜控释肥的农用安全性, 从而为控释肥的改进和推广应用提供科学依据,也为硫包膜肥料长期大量施用可能给土壤带来的问题提出预警.结果表明:在玉米生长期,控释肥硫膜并没有显著影响土壤的pH值.玉米生长的第68天时,施加0.5倍、1倍、2倍量的硫膜分别使土壤交换性酸增加了0.038,0.057,0.040 cmol/kg,使土壤交换性Al3+分别增加了14.29%,15.15%,11.11%,且差异都达显著性水平,但在玉米的其它生长时期,硫膜并未显著影响土壤中交换性酸、交换性Al3+交换性H+的含量.在玉米生长后期控释肥硫膜能够增加土壤交换性钙离子和交换性镁离子含量,增加交换性钾离子含量.

  18. Brazilian energy balance 1996: calendar year 1995

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the calendar year 1995. It's divided into nine sections, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy foreign trading; transformation center balances ;energy resources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  19. Brazilian energy balance 1998: calendar year 1997

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the calendar year 1995. It's divided into nine sections, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy foreign trading; transformation center balances ;energy resources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  20. Brazilian energy balance 1995: calendar year 1994

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 1998. It is divided into nine sections: a summary from 1979 to 1994; energy supply and demand by source; energy consumption by sector; energy foreign trading; transformation centers balances; energy resources and reserves; energy and socio-economy; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  1. Brazilian energy balance 1997: calendar year 1996

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 1998. It is divided into nine sections: a summary from 1981 to 1996; energy supply and demand by source; energy consumption by sector; energy foreign trading; transformation centers balances; energy resources and reserves; energy and socio-economy; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  2. Brazilian energy balance 1999: calendar year 1998

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 1998. It is divided into nine sections: a summary from 1983 to 1998; energy supply and demand by source; energy consumption by sector; energy foreign trading; transformation centers balances; energy resources and reserves; energy and socio-economy; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  3. Brazilian energy balance 2001: calendar year 2000

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 1999. It is divided into nine sections: a summary from 1984 to 1999; energy supply and demand by source; energy consumption by sector; energy foreign trading; transformation centers balances; energy resources and reserves; energy and socio-economy; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  4. Brazilian energy balance 2000: calendar year 1999

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in all the sectors of the Brazilian economy, for the calendar year 1999. It is divided into nine sections: a summary from 1984 to 1999; energy supply and demand by source; energy consumption by sector; energy foreign trading; transformation centers balances; energy resources and reserves; energy and socio-economy; regional parameters, and appendices including installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances

  5. Introduction to energy balance of biomass production

    During last years, energy crops have been envisaged as an interesting alternative to biomass residues utilization as renewable energy source. In this work, main parameters used in calculating the energy balance of an energy crop are analyzed. The approach consists of determining energy equivalents for the different inputs and outputs of the process, thus obtaining energy ratios of the system, useful to determine if the energy balance is positive, that is, if the system generates energy. Energy costs for inputs and assessment approaches for energy crop yields (output) are provided. Finally, as a way of illustration, energy balances of some representative energy crops are shown. (Author) 15 refs

  6. Point configurations that are asymmetric yet balanced

    Cohn, Henry; Kumar, Abhinav; Schuermann, Achill

    2008-01-01

    A configuration of particles confined to a sphere is balanced if they are in equilibrium under all force laws (that act between pairs of points with strength given by a fixed function of distance). It is straightforward to show that every sufficiently symmetrical configuration is balanced, but the converse is far from obvious. In 1957 Leech completely classified the balanced configurations in R^3, and his classification is equivalent to the converse for R^3. In this paper we disprove the converse in high dimensions. We construct several counterexamples, including one with trivial symmetry group.

  7. Strain gage balances and buffet gages

    Ferris, A. T.

    1983-01-01

    One-piece strain gage force balances were developed for use in the National Transonic Facility (NTF). This was accomplished by studying the effects of the cryogenic environment on materials, strain gages, cements, solders, and moisture proofing agents, and selecting those that minimized strain gage output changes due to temperature. In addition, because of the higher loads that may be imposed by the NTF, these balances are designed to carry a larger load for a given diameter than conventional balances. Full cryogenic calibrations were accomplished, and wind tunnel results that were obtained from the Langley 0-3-Meter Transonic Cryogenic Tunnel were used to verify laboratory test results.

  8. Radiation balances and the solar constant

    Crommelynck, D.

    1981-01-01

    The radiometric concepts are defined in order to consider various types of radiation balances and relate them to the diabetic form of the energy balance. Variability in space and time of the components of the radiation field are presented. A specific concept for sweeping which is tailored to the requirements is proposed. Finally, after establishing the truncated character of the present knowledge of the radiation balance. The results of the last observations of the solar constant are given. Ground and satellite measurement techniques are discussed.

  9. EFFECT OF WOBBLE BOARD BALANCE TRAINING PROGRAM ON STATIC BALANCE, DYNAMIC BALANCE & TRIPLE HOP DISTANCE IN MALE COLLEGIATE BASKETBALL ATHLETE

    Neeraj Panwar, MPT (Sports); Gaurav Kadyan, MPT (Sports); Aseem Gupta, MPT (Sports); Ravinder Narwal, MPT (Ortho,Cardiopulmonary)

    2014-01-01

    Aim & Objective: The aim of the study was to determine the effect of wobble board balance training program on static & dynamic balance & on triple hop distance in male collegiate basketball athletes. Methodology: Fifty healthy basketball players within a age group of 18-22 yrs. were randomly selected with a baseline BESS score between 6 to 14 & modified SEBT score equal to or greater than 94 (till 100) and they randomly divided into control (n-25) & training group (n-25).The training grou...

  10. Surface Mass Balance of the Columbia Glacier, Alaska, 1978 and 2010 Balance Years

    O'Neel, Shad

    2012-01-01

    Although Columbia Glacier is one of the largest sources of glacier mass loss in Alaska, surface mass balance measurements are sparse, with only a single data set available from 1978. The dearth of surface mass-balance data prohibits partitioning of the total mass losses between dynamics and surface forcing; however, the accurate inclusion of calving glaciers into predictive models requires both dynamic and climatic forcing of total mass balance. During 2010, the U.S. Geological Survey collected surface balance data at several locations distributed over the surface of Columbia Glacier to estimate the glacier-wide annual balance for balance year 2010 using the 2007 area-altitude distribution. This report also summarizes data collected in 1978, calculates the 1978 annual surface balance, and uses these observations to constrain the 2010 values, particularly the shape of the balance profile. Both years exhibit balances indicative of near-equilibrium surface mass-balance conditions, and demonstrate the importance of dynamic processes during the rapid retreat.

  11. Let's bring balance to health care.

    Fitzpatrick, Melissa A

    2002-03-01

    Consider implementing the balanced scorecard--a performance management method that allows you to view your work from four perspectives: customer, internal business, learning and growth, and financial. PMID:11923980

  12. Microwave balanced oscillators and frequency doublers

    Siripon, N

    2002-01-01

    The research presented in this thesis is on the application of the injection-locked oscillator technique to microwave balanced oscillators. The balanced oscillator design is primarily analysed using the extended resonance technique. A transmission line is connected between the two active devices, so that the active device resonate each other. The electrical length of the transmission line is also analysed for the balanced oscillation condition. The balanced oscillator can be viewed with the negative resistance model and the feedback model. The former model is characterised at a circuit plane where the feedback network is cut. By using both the negative-resistance oscillator model and the feedback model, the locking range of the oscillator is analysed by extending Kurokawa's theory. This analysis demonstrates the locking range of the injection phenomenon, where the injection frequency is either close to the free-running frequency, close to (1/n) x free-running frequency or close to n x the free-running frequen...

  13. Torsion Balance Test of Einstein's Equivalence Principle

    Abercrombie, Michael; Archibald, Adam; Nussinov, Tsitsi; Wagoner, Kasey; Cowsik, Ramanath

    2016-03-01

    We have developed a torsion balance experiment to test the equivalence principle (EP) which follows the solar attractor approach pioneered by Dicke in the early 1960s. By monitoring the response of a balance arranged as a composition dipole with an azimuthally symmetric mass distribution to the gravitational field produced by the Sun, we search for a diurnal modulation of the balance which would indicate a violation of the EP. Since reporting on the status of this experiment last year, the instrument has begun collecting data at a remote underground site. This talk will cover the design and fundamental sensitivity of the balance, and present the results of preliminary analysis of over 1200 hours of data.

  14. Jet Exit Rig Six Component Force Balance

    Castner, Raymond; Wolter, John; Woike, Mark; Booth, Dennis

    2012-01-01

    A new six axis air balance was delivered to the NASA Glenn Research Center. This air balance has an axial force capability of 800 pounds, primary airflow of 10 pounds per second, and a secondary airflow of 3 pounds per second. Its primary use was for the NASA Glenn Jet Exit Rig, a wind tunnel model used to test both low-speed, and high-speed nozzle concepts in a wind tunnel. This report outlines the installation of the balance in the Jet Exit Rig, and the results from an ASME calibration nozzle with an exit area of 8 square-inches. The results demonstrated the stability of the force balance for axial measurements and the repeatability of measurements better than 0.20 percent.

  15. Load balancing in integrated optical wireless networks

    Yan, Ying; Dittmann, Lars; Wong, S-W.;

    2010-01-01

    In this paper, we tackle the load balancing problem in Integrated Optical Wireless Networks, where cell breathing technique is used to solve congestion by changing the coverage area of a fully loaded cell tower. Our objective is to design a load balancing mechanism which works closely with the...... issues are outlined and a cost function based optimization model is developed for power management. In particularly, two alternative feedback schemes are proposed to report wireless network status. Simulation results show that our proposed load balancing mechanism improves network performances....... integrated control scheme so as to maximize overall network throughput in the integrated network architecture. To the best of our knowledge no load balancing mechanisms, especially based on the Multi-Point Control Protocol (MPCP) defined in the IEEE 802.3ah, have been proposed so far. The major research...

  16. Balancing the books accounting for librarians

    Kirk, Rachel A

    2012-01-01

    Balancing the Books: Accounting for Librarians fills the gap that exists in literature on library acquisitions accounting. By covering essential accounting concepts, budgeting, government regulations that pertain to libraries, as well as accounting measur

  17. Walking (Gait), Balance, and Coordination Problems

    ... and include: poor balance and slowed walking reduced proprioception (the sensation of where your body parts are ... MS Connection Visit MSConnection.org symptoms of ms proprioception" the 6th sense of ms..please learn!! general ...

  18. Surface melt dominates Alaska glacier mass balance

    Larsen Chris F; Burgess, E; Arendt, A.A.; O'Neel, Shad; Johnson, A.J.; Kienholz, C.

    2015-01-01

    Mountain glaciers comprise a small and widely distributed fraction of the world's terrestrial ice, yet their rapid losses presently drive a large percentage of the cryosphere's contribution to sea level rise. Regional mass balance assessments are challenging over large glacier populations due to remote and rugged geography, variable response of individual glaciers to climate change, and episodic calving losses from tidewater glaciers. In Alaska, we use airborne altimetry from 116 glaciers to estimate a regional mass balance of −75 ± 11 Gt yr−1 (1994–2013). Our glacier sample is spatially well distributed, yet pervasive variability in mass balances obscures geospatial and climatic relationships. However, for the first time, these data allow the partitioning of regional mass balance by glacier type. We find that tidewater glaciers are losing mass at substantially slower rates than other glaciers in Alaska and collectively contribute to only 6% of the regional mass loss.

  19. A Multipurpose Experiment with an Electronic Balance

    Ganci, S.

    2008-01-01

    This short article describes some useful and quick applications of a cooking electronic balance. Newton's third law, Archimedes buoyancy and an estimate of relative density are accomplished in a very simple way. (Contains 1 figure.)

  20. Strategic management by balanced development: meaning

    Yevtushenko Natalya Olexandrivna

    2016-02-01

    Full Text Available Based on analyzes of references it was found out the meaning of «management», «strategic management», «development of enterprise», «balanced development» and were proved their connections. It was described authorial interpretation of definition “strategic management by balanced development”. The next descriptions were separated: presence of quantitative and quality changes, adaptation to influence of internal and external environment factors. It was set that a human capital is the main source of the balanced development. On the basis of generalization and systematization of existent interpretations was offered authorial determination of essence of concept «strategic management by balanced development of enterprise».