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Sample records for sweat electrolyte composition

  1. Sweat rate and sweat electrolyte composition in international female soccer players during game specific training.

    Science.gov (United States)

    Kilding, A E; Tunstall, H; Wraith, E; Good, M; Gammon, C; Smith, C

    2009-06-01

    The purpose of this study was to determine the sweat rate and sweat electrolyte composition in female international level soccer players. Thirteen soccer players performed two 90 min soccer-specific training sessions (T1 and T2) on separate days. Hydration status was determined prior to each session and sweat loss, sweat rate and sweat composition (Na (+), K (+), Mg (++) and Ca (+)) were determined from patches worn during training. The mean sweat rate during T1 and T2 was 0.50+/-0.20 and 0.43+/-0.18 L.h (-1) respectively (P>0.05). The mean sweat electrolyte composition during T1 and T2 was: [Na (+)]: 43.9+/-15.0 and 46.2+/-7.9 mmol.L (-1); [K (+)]: 6.1+/-1.1 and 5.2+/-1.1 mmol.L (-1); [Mg (++)]: 0.1+/-0.0 and 0.1+/-0.0 mmol.L (-1); [Ca (+)]: 1.2+/-0.5 and 0.7+/-0.1 mmol.L (-1), respectively. When data from T1 and T2 were combined, there were no relationships between sweat rate and sweat concentration of any electrolyte. In conclusion, the sweat rate and sweat electrolyte losses in this cohort of international female soccer players, during soccer-specific training in cool conditions, were small. Electrolyte losses of this magnitude are unlikely to require special consideration in terms of optimising player hydration.

  2. Sweating, thirst perception and plasma electrolyte composition in ...

    African Journals Online (AJOL)

    Thirst is a perception, the subjective experience evoked by fluid deficits. Exercise induces sweating and subsequently electrolyte loss and thirst but there is little documented on post exercise thirst perception in women of varying body mass indices. 40 apparently healthy young women (19-25years) in the follicular phase of ...

  3. Sweat electrolytes test

    Science.gov (United States)

    Sweat test; Sweat chloride; Iontophoretic sweat test; CF - sweat test; Cystic fibrosis - sweat test ... A colorless, odorless chemical that causes sweating is applied to a small area on an arm or leg. An electrode is then attached to the spot. A weak electrical ...

  4. Regional variations in transepidermal water loss, eccrine sweat gland density, sweat secretion rates and electrolyte composition in resting and exercising humans

    Science.gov (United States)

    2013-01-01

    Literature from the past 168 years has been filtered to provide a unified summary of the regional distribution of cutaneous water and electrolyte losses. The former occurs via transepidermal water vapour diffusion and secretion from the eccrine sweat glands. Daily insensible water losses for a standardised individual (surface area 1.8 m2) will be 0.6–2.3 L, with the hands (80–160 g.h−1) and feet (50–150 g.h−1) losing the most, the head and neck losing intermediate amounts (40–75 g.h−1) and all remaining sites losing 15–60 g.h−1. Whilst sweat gland densities vary widely across the skin surface, this same individual would possess some 2.03 million functional glands, with the highest density on the volar surfaces of the fingers (530 glands.cm−2) and the lowest on the upper lip (16 glands.cm−2). During passive heating that results in a resting whole-body sweat rate of approximately 0.4 L.min−1, the forehead (0.99 mg.cm−2.min−1), dorsal fingers (0.62 mg.cm−2.min−1) and upper back (0.59 mg.cm−2.min−1) would display the highest sweat flows, whilst the medial thighs and anterior legs will secrete the least (both 0.12 mg.cm−2.min−1). Since sweat glands selectively reabsorb electrolytes, the sodium and chloride composition of discharged sweat varies with secretion rate. Across whole-body sweat rates from 0.72 to 3.65 mg.cm−2.min−1, sodium losses of 26.5–49.7 mmol.L−1 could be expected, with the corresponding chloride loss being 26.8–36.7 mmol.L−1. Nevertheless, there can be threefold differences in electrolyte losses across skin regions. When exercising in the heat, local sweat rates increase dramatically, with regional glandular flows becoming more homogeneous. However, intra-regional evaporative potential remains proportional to each local surface area. Thus, there is little evidence that regional sudomotor variations reflect an hierarchical distribution of sweating either at rest or during exercise. PMID:23849497

  5. Regional variations in transepidermal water loss, eccrine sweat gland density, sweat secretion rates and electrolyte composition in resting and exercising humans.

    Science.gov (United States)

    Taylor, Nigel As; Machado-Moreira, Christiano A

    2013-02-01

    Literature from the past 168 years has been filtered to provide a unified summary of the regional distribution of cutaneous water and electrolyte losses. The former occurs via transepidermal water vapour diffusion and secretion from the eccrine sweat glands. Daily insensible water losses for a standardised individual (surface area 1.8 m2) will be 0.6-2.3 L, with the hands (80-160 g.h-1) and feet (50-150 g.h-1) losing the most, the head and neck losing intermediate amounts (40-75 g.h-1) and all remaining sites losing 15-60 g.h-1. Whilst sweat gland densities vary widely across the skin surface, this same individual would possess some 2.03 million functional glands, with the highest density on the volar surfaces of the fingers (530 glands.cm-2) and the lowest on the upper lip (16 glands.cm-2). During passive heating that results in a resting whole-body sweat rate of approximately 0.4 L.min-1, the forehead (0.99 mg.cm-2.min-1), dorsal fingers (0.62 mg.cm-2.min-1) and upper back (0.59 mg.cm-2.min-1) would display the highest sweat flows, whilst the medial thighs and anterior legs will secrete the least (both 0.12 mg.cm-2.min-1). Since sweat glands selectively reabsorb electrolytes, the sodium and chloride composition of discharged sweat varies with secretion rate. Across whole-body sweat rates from 0.72 to 3.65 mg.cm-2.min-1, sodium losses of 26.5-49.7 mmol.L-1 could be expected, with the corresponding chloride loss being 26.8-36.7 mmol.L-1. Nevertheless, there can be threefold differences in electrolyte losses across skin regions. When exercising in the heat, local sweat rates increase dramatically, with regional glandular flows becoming more homogeneous. However, intra-regional evaporative potential remains proportional to each local surface area. Thus, there is little evidence that regional sudomotor variations reflect an hierarchical distribution of sweating either at rest or during exercise.

  6. Towards Addressing the Body Electrolyte Environment via Sweat Analysis:Pilocarpine Iontophoresis Supports Assessment of Plasma Potassium Concentration

    OpenAIRE

    Vairo, Donato; Bruzzese, Laurie; Marlinge, Marion; Fuster, Lea; Adjriou, Nabil; Kipson, Nathalie; Brunet, Philippe; Cautela, Jennifer; Jammes, Yves; Mottola, Giovanna; Burtey, Stephane; Ruf, Jean; Guieu, Regis; Fenouillet, Emmanuel

    2017-01-01

    Electrolyte concentration in sweat depends on environmental context and physical condition but also on the pathophysiological status. Sweat analyzers may be therefore the future way for biological survey although how sweat electrolyte composition can reflect plasma composition remains unclear. We recruited 10 healthy subjects and 6 patients to have a broad range of plasma electrolyte concentrations (chloride, potassium and sodium) and pH. These variables were compared to those found in sweat ...

  7. Towards Addressing the Body Electrolyte Environment via Sweat Analysis:Pilocarpine Iontophoresis Supports Assessment of Plasma Potassium Concentration.

    Science.gov (United States)

    Vairo, Donato; Bruzzese, Laurie; Marlinge, Marion; Fuster, Lea; Adjriou, Nabil; Kipson, Nathalie; Brunet, Philippe; Cautela, Jennifer; Jammes, Yves; Mottola, Giovanna; Burtey, Stephane; Ruf, Jean; Guieu, Regis; Fenouillet, Emmanuel

    2017-09-18

    Electrolyte concentration in sweat depends on environmental context and physical condition but also on the pathophysiological status. Sweat analyzers may be therefore the future way for biological survey although how sweat electrolyte composition can reflect plasma composition remains unclear. We recruited 10 healthy subjects and 6 patients to have a broad range of plasma electrolyte concentrations (chloride, potassium and sodium) and pH. These variables were compared to those found in sweat produced following cycling exercise or pilocarpine iontophoresis, a condition compatible with operating a wearable device. We found no correlation between plasma and sweat parameters when exercise-induced sweat was analyzed, and we could identify a correlation only between plasma and sweat potassium concentration (R = 0.78, p sweat was induced using pilocarpine iontophoresis. We tested measurement repeatability in sweat at 24hr-interval for 3 days in 4 subjects and found a great intra-individual variability regarding all parameters in exercise-induced sweat whereas similar electrolyte levels were measured in pilocarpine-induced sweat. Thus, electrolyte concentration in sweat sampled following physical activity does not reflect concentration in plasma while pilocarpine iontophoresis appears to be promising to reproducibly address sweat electrolytes, and to make an indirect evaluation of plasma potassium concentration in chronic kidney disease and arrhythmia.

  8. Interindividual variability in sweat electrolyte concentration in marathoners.

    Science.gov (United States)

    Lara, Beatriz; Gallo-Salazar, César; Puente, Carlos; Areces, Francisco; Salinero, Juan José; Del Coso, Juan

    2016-01-01

    Sodium (Na(+)) intake during exercise aims to replace the Na(+) lost by sweat to avoid electrolyte imbalances, especially in endurance disciplines. However, Na(+) needs can be very different among individuals because of the great inter-individual variability in sweat electrolyte concentration. The aim of this investigation was to determine sweat electrolyte concentration in a large group of marathoners. A total of 157 experienced runners (141 men and 16 women) completed a marathon race (24.4 ± 3.6 °C and 27.7 ± 4.8 % of humidity). During the race, sweat samples were collected by using sweat patches placed on the runners' forearms. Sweat electrolyte concentration was measured by using photoelectric flame photometry. As a group, sweat Na(+) concentration was 42.9 ± 18.7 mmol·L(-1) (minimal-maximal value = 7.0-95.5 mmol·L(-1)), sweat Cl(-) concentration was 32.2 ± 15.6 mmol·L(-1) (7.3-90.6 mmol·L(-1)) and sweat K(+) concentration was 6.0 ± 0.9 mmol·L(-1) (3.1-8.0 mmol·L(-1)). Women presented lower sweat Na(+) (33.9 ± 12.1 vs 44.0 ± 19.1 mmol·L(-1); P = 0.04) and sweat Cl(-) concentrations (22.9 ± 10.5 vs 33.2 ± 15.8 mmol·L(-1); P = 0.01) than men. A 20 % of individuals presented a sweat Na(+) concentration higher than 60 mmol·L(-1) while this threshold was not surpassed by any female marathoner. Sweat electrolyte concentration did not correlate to sweat rate, age, body characteristics, experience or training. Although there was a significant correlation between sweat Na(+) concentration and running pace (r = 0.18; P = 0.03), this association was weak to interpret that sweat Na(+) concentration increased with running pace. The inter-individual variability in sweat electrolyte concentration was not explained by any individual characteristics except for individual running pace and sex. An important portion (20 %) of marathoners might need special sodium intake recommendations due to

  9. Sweat composition in exercise and in heat.

    Science.gov (United States)

    Verde, T; Shephard, R J; Corey, P; Moore, R

    1982-12-01

    Sweat samples were collected from the forearms of eight male volunteers using light gauze pads applied for 20-min periods. Preliminary trials indicated that this technique yielded realistic figures for both sweat volume and sweat composition. Tests were conducted under three conditions: a) outdoor exercise, cool environment; b) indoor exercise, normal room temperatures; and c) sauna exposure. In all environments, proximal forearm samples indicated a larger sweat secretion than distal forearm or hand samples. [Mg2+] decreased as sweat flow increased, but after allowance for interindividual differences of sweat volume, [Na+], [K+], [Ca2+], and [Cl-] were independent of sweat flow rates. The differential effect of sweat flow suggests active regulation rather than contamination. Interindividual differences of sweat composition could not be explained in terms of differences in personal fitness. Sauna bathing yielded sweat with a higher [Mg2+] and [Ca2+] content than did exercise; however, [Na+], [K+], and [Cl-] were similar for the three experimental conditions. Again, the data are best explained in terms of an active regulation of sweat composition. Total ionic losses do not seem sufficient to deplete body mineral reserves unless many days of training are undertaken in a hot climate.

  10. Equine sweat composition: effects of adrenaline infusion, exercise and training.

    Science.gov (United States)

    McConaghy, F F; Hodgson, D R; Evans, D L; Rose, R J

    1995-11-01

    Significant alterations in plasma electrolyte concentrations have been reported in horses following prolonged exercise, resulting from loss of hypertonic sweat. Sweat was collected from 10 horses undergoing a 10 week training programme; 5 at moderate intensity, to speeds of 10 m/s and 5 at low intensity, to speeds of 5 m/s. Sweat was collected from 2 sites in response to a submaximal exercise test (30 min at 50% VO2max and during an adrenaline infusion (dose mean +/- s.d.; 0.3 +/- 0.05 g/kg over 30 min). Sweat samples were analysed for sodium, chloride, potassium, protein, magnesium, calcium and urea concentrations. Sweat produced in response to exercise and adrenaline infusion was hypertonic and showed no significant differences in composition following training. However, the [NaCl] of sweat rose with increased duration of sweating. Sweat produced in response to adrenaline infusion was more dilute than that produced in response to exercise, which may be related to sympathetic outflow during exercise.

  11. Concentration of electrolytes in the sweat of malnourished children.

    OpenAIRE

    Rodrigues, M. E.; M. C. MELO; Reis, F J; Penna, F J

    1994-01-01

    The sweat test was performed by the method of Gibson and Cooke on 36 children with second and third degree malnutrition, aged from 2 months to 4 years. The results were compared with those from 32 healthy, well nourished controls in the same age range. Determinations were made of sodium and chloride concentrations, chloride/sodium ratio, and the sum of the concentrations of the two electrolytes in each sample. The malnourished children were found to have higher sodium and chloride concentrati...

  12. Sweating

    Science.gov (United States)

    ... Home Body Looking and feeling your best Sweating Sweating You might think that you are only supposed to sweat when you are hot, but once you hit puberty, you will also sweat when you are nervous. Your sweat glands, which ...

  13. Whole body sweat collection in humans: an improved method with preliminary data on electrolyte content.

    Science.gov (United States)

    Shirreffs, S M; Maughan, R J

    1997-01-01

    Previous methods used to collect human sweat for electrolyte analysis have been criticized because they involve only regional sampling or because of methodological problems associated with whole body-washdown techniques. An improved method for collection of whole body sweat from exercising subjects is described. It involved construction of a plastic frame that supports a large plastic bag within which the subject exercises. The subject and the equipment are washed with distilled, deionized water before exercise begins. After exercise is completed, the subject and equipment are again washed with water containing a marker not present in sweat (ammonium sulfate). Total sweat loss is calculated from the change in body mass, and the volume of sweat not evaporated is calculated from dilution of the added marker. Recovery of added water was 102 +/- 2% (SD) of the added volume, and recovery of added electrolytes was 99 +/- 2% for sodium, 98 +/- 9% for potassium, and 101 +/- 4% for chloride. Repeated trials (n = 4) on five subjects to establish the reproducibility of the method gave a coefficient of variation of 17 +/- 5% for sodium, 23 +/- 6% for potassium, and 15 +/- 6% for chloride. These values include the biological variability between trials as well as the error within the method. The biological variability thus appears to be far greater than the methodological error. Normal values for the composition of sweat induced by exercise in a hot, humid environment in healthy young men and women were (in mM) 50.8 +/- 16.5 sodium, 4.8 +/- 1.6 potassium, 1.3 +/- 0.9 calcium, 0.5 +/- 0.5 magnesium, and 46.6 +/- 13.1 chloride.

  14. Composition of sweat of the horse during prolonged epinephrine (adrenaline) infusion, heat exposure, and exercise.

    Science.gov (United States)

    Kerr, M G; Snow, D H

    1983-08-01

    Temporal changes in sweat composition were studied in 4 horses during epinephrine (adrenaline) infusion (0.13 to 0.31 micrograms/kg/min for 3 hours), heat exposure (41 C, [33 C wet bulb] for 5 to 6 hours), and exercise (16 to 18 km/hr for 58 to 80 km). Four ponies also were studied during heat exposure. Sweat produced by each of the stimuli was hypertonic for Na+, K+, and Cl-. These electrolyte concentrations remained constant during the central period of the experiments, with changes occurring near the beginning and toward the end. The Na+ was significantly higher and K+ significantly lower in epinephrine-induced sweat than in heat-induced sweat, and the pattern of change in sweat Na/K ratio varied among the 3 stimuli. The Ca2+ concentration decreased with time and was hypotonic after 15 minutes of epinephrine-induced sweating. Concentrations of Mg2+ and protein decreased exponentially with time. There was a high correlation between them, although the Mg2+ was not protein-bound. Sweat urea concentration was directly related to plasma urea concentration. When plasma glucose concentration became greater than 10 to 12 mmole/L during epinephrine infusion, glucose appeared in the sweat and its concentration rose to 8 to 12 mmole/L of sweat when plasma glucose was more than 20 mmole/L.

  15. Sweat

    Science.gov (United States)

    Sweat is a clear, salty liquid produced by glands in your skin. Sweating is how your body cools itself. You sweat mainly under your arms and on your feet and palms. When sweat mixes with bacteria on your skin, it can ...

  16. Variations in regional sweat composition in normal human males.

    Science.gov (United States)

    Patterson, M J; Galloway, S D; Nimmo, M A

    2000-11-01

    This project aimed to quantify the regional distribution of sweat composition over the skin surface and to determine whether sweat constituent concentrations collected from regional sites can estimate whole-body concentrations. Ten males cycled for 90 min in a 20 degrees C (50% relative humidity) environment at 45% peak aerobic power. Sweat was collected from eleven skin regions and the whole body, using a wash-down technique. Strong relationships were evident between the regional and whole-body sweat [Na+] and [Cl-], such that the thigh and calf exhibited greater correlation coefficients than area-weighted means derived from four and eight skin regions. Therefore, in this particular protocol the whole-body sweat [Na+] and [Cl-] could be predicted from regional sweat collections. Relationships between sweat constituents were evident for sweat [Na+] and pH, and sweat [K+] and [lactate] when data were pooled between skin regions and subjects. To our knowledge this is the first investigation to report a positive relationship between sweat [K+] and [lactate]. The exact mechanism responsible for the positive relationship between sweat [K+] and [lactate] is uncertain although it is speculated to occur at the secretory coil.

  17. Sweating Rate and Sweat Sodium Concentration in Athletes: A Review of Methodology and Intra/Interindividual Variability

    OpenAIRE

    Baker, Lindsay B.

    2017-01-01

    Athletes lose water and electrolytes as a consequence of thermoregulatory sweating during exercise and it is well known that the rate and composition of sweat loss can vary considerably within and among individuals. Many scientists and practitioners conduct sweat tests to determine sweat water and electrolyte losses of athletes during practice and competition. The information gleaned from sweat testing is often used to guide personalized fluid and electrolyte replacement recommendations for a...

  18. Influence of digoxin and diuretic therapy on sweat fluid composition.

    Science.gov (United States)

    Mor, A; Benzon, L; Aladjem, M

    1985-01-01

    The effect of digitalis and diuretic therapy on sweat fluid composition was investigated. Patients treated for congestive heart failure with a combination of digoxin and diuretics demonstrated a higher concentration of sodium and chloride in their sweat fluid when compared to age-matched controls. The administration of diuretics alone did not affect sweat fluid composition. The digoxin-induced increase in sodium concentration was significantly higher than that observed for chloride. These data suggest that digoxin markedly inhibits sodium reabsorption along the sweat gland tubule, whereas chloride transport is affected to a lesser degree. A significant correlation between sweat fluid sodium and serum digoxin concentrations was observed. We conclude that the increased digoxin-induced sweat sodium and chloride losses may affect sodium homeostasis in patients with congestive heart failure.

  19. Sweat composition in Arabian horses performing endurance exercise on forage-based, low Na rations.

    Science.gov (United States)

    Spooner, H S; Nielsen, B D; Schott, H C; Harris, P A

    2010-11-01

    Excessive sweat loss during endurance exercise may lead to electrolyte disturbances and previous research suggests dietary factors may affect hydration status. While investigating the effect of dietary fibre type on hydration status, sweat samples were collected which allowed for the evaluation of sweat composition in horses consuming forage-based, low sodium (Na) rations. To investigate sweat composition in Arabian horses performing endurance type exercise while fed forage-based, rations low in Na. Six 2-year-old Arabian horses were fed, according to a replicated 3 × 3 Latin square, either grass hay (G), 50:50 grass hay:alfalfa hay (GA), or 50:50 grass hay: chopped fibres (GM) without any additional electrolyte supplementation. After 14 days on each diet, horses performed a 60 km treadmill exercise test. Sweat was collected from sealed pouches on the dorsal thorax after each of four 15 km exercise bouts. Intake (g/day) of Na (2.5 ± 0.4), Cl (72 ± 16), and Mg (18 ± 3) were not different between diets but K and Ca intakes (g/day) were greater (P sweat pH (7.65 ± 0.04) or concentrations (mmol/l) of K (46 ± 3), Cl (133 ± 7), Ca (8.5 ± 1.1), or Mg (2.3 ± 0.3); yet diet did influence sweat Na concentration (P sweat constituents due to diet were observed, but more importantly both Na and Cl concentration are lower than those previously reported perhaps due to low dietary Na intake or breed of animal. © 2010 EVJ Ltd.

  20. Adhesive RFID Sensor Patch for Monitoring of Sweat Electrolytes.

    Science.gov (United States)

    Rose, Daniel P; Ratterman, Michael E; Griffin, Daniel K; Hou, Linlin; Kelley-Loughnane, Nancy; Naik, Rajesh R; Hagen, Joshua A; Papautsky, Ian; Heikenfeld, Jason C

    2015-06-01

    Wearable digital health devices are dominantly found in rigid form factors such as bracelets and pucks. An adhesive radio-frequency identification (RFID) sensor bandage (patch) is reported, which can be made completely intimate with human skin, a distinct advantage for chronological monitoring of biomarkers in sweat. In this demonstration, a commercial RFID chip is adapted with minimum components to allow potentiometric sensing of solutes in sweat, and surface temperature, as read by an Android smartphone app with 96% accuracy at 50 mM Na(+) (in vitro tests). All circuitry is solder-reflow integrated on a standard Cu/polyimide flexible-electronic layer including an antenna, but while also allowing electroplating for simple integration of exotic metals for sensing electrodes. Optional paper microfluidics wick sweat from a sweat porous adhesive allowing flow to the sensor, or the sensor can be directly contacted to the skin. The wearability of the patch has been demonstrated for up to seven days, and includes a protective textile which provides a feel and appearance similar to a standard Band-Aid. Applications include hydration monitoring, but the basic capability is extendable to other mM ionic solutes in sweat (Cl(-), K(+), Mg(2+), NH4(+), and Zn(2+)). The design and fabrication of the patch are provided in full detail, as the basic components could be useful in the design of other wearable sensors.

  1. [Estimation of the sweat composition of fatty acids].

    Science.gov (United States)

    Solovskaia, S S; Varus, V I; Briuzgina, T S; Belov, A A; Ivanov, D A

    2007-05-01

    Changes in the fatty acid composition of sweat lipid were studied in persons whose activity was associated with military service. There were significant changes in essential fatty acids of sweat lipids, which made it possible to use this noninvasive biological object as a criterion for rating dysadaptive processes in armed forces personnel.

  2. Sweating

    Science.gov (United States)

    ... treat mental disorders Menopause Spicy foods (known as "gustatory sweating") Warm temperatures Withdrawal from alcohol or narcotic ... D, Chelimsky G. Disorders of the autonomic nervous system. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta ...

  3. Sweating rate and sweat composition during exercise and recovery in ambient heat and humidity.

    Science.gov (United States)

    McCutcheon, L J; Geor, R J; Hare, M J; Ecker, G L; Lindinger, M I

    1995-11-01

    The objective of this study was to determine the composition and extent of sweat losses during submaximal exercise under hot and humid conditions and to compare these findings with the same exercise protocol conducted under cool, dry and hot, dry conditions. Five Thoroughbred horses (age 3 to 6) completed exercise tests under each of 3 environmental conditions in random order: cool, dry (CD), room temperature (T) = 20 degrees C, relative humidity (RH) = 45-55%; hot, dry (HD), T = 32-34 degrees C, RH = 45-55%; and hot, humid (HH), T = 32-34 degrees C, RH = 80-85%. Horses exercised at 50% of their predetermined VO2max on a treadmill set at a 10% slope until attainment of a pulmonary artery blood temperature of 41.5 degrees C followed by a 60 min recovery. Sweat was collected from a sealed polyethylene pouch enclosing a 150 cm2 area on the lateral thorax. During exercise and the first 30 min of recovery, sweat fluid losses were 7.9 +/- 0.7 litres, 9.9 +/- 0.5 litres and 6.6 +/- 1.2 litres (mean +/- s.e.m.) for CD, HD and HH, respectively. Sweating rate (SR), calculated from sweat volume per unit area of enclosed skin, was lowest in CD and similar in HD and HH during exercise such that at end of exercise in HH (16.5 min) calculated sweat losses were approximately 5% and 32% higher than in HD and CD, respectively. In recovery, SR declined in all conditions but was significantly lower in CD (P Sweating was detectable until 30 min recovery in CD, 45 min recovery in HD and 60 min recovery in HH. Sweat composition and osmolality was different under the 3 environmental conditions and changed gradually during exercise and recovery in all conditions. Osmolality and [Na] was highest in HD and lowest in CD. During exercise, [Na] increased with increasing SR. Although exercise duration was significantly decreased in HH (16.5 +/- 1 min) when compared to HD (28 +/- 2 min) and CD (37 +/- 2 min), fluid and ion losses in HH were comparable to those in HD as a result of a high SR and

  4. Effect of plasma prolactin on sweat rate and sweat composition during exercise in men.

    Science.gov (United States)

    Boisvert, P; Brisson, G R; Péronnet, F

    1993-05-01

    We investigated the role of the exercise-induced elevation of plasma prolactin (PRL) concentration on sweat rate and composition during prolonged exercise in men. Two groups of healthy young males (20-26 yr old) showing a high (high responders; n = 8) or a low (low responders; n = 7) response of plasma PRL concentration to exercise were studied during a 60-min period of exercise on a cycle ergometer (65% maximum O2 consumption) in warm conditions (26.2 +/- 0.1 degrees C; 57 +/- 1% relative humidity), 1 h after receiving 1.25 mg bromocriptine (BRC) per os or a placebo. In high responders, administration of BRC totally abolished the threefold increase in plasma PRL observed in response to exercise with placebo [placebo, 10 +/- 2 (rest) and 30 +/- 2 micrograms/l (exercise); BRC, 9 +/- 1 (rest) and 8 +/- 1 microgram/l (exercise)]. The latter was associated with a significant decrease in sweat rate (2.7 +/- 0.5 to 1.9 +/- 0.3 microliter.cm-2.min-1) and a significant increase in sweat Na+ concentration (57 +/- 7 to 68 +/- 5 mmol/l). BRC also reduced the small response in plasma PRL concentration observed in low responders [placebo, 10 +/- 1 (rest) and 15 +/- 1 microgram/l (exercise); BRC, 9 +/- 1 (rest) and 7 +/- 1 microgram/l (exercise)], but this was not associated with any change in sweat rate (2.2 +/- 0.2 to 1.9 +/- 0.3 microliter.cm-2.min-1) or in sweat Na+ concentration (63 +/- 10 to 64 +/- 9 mmol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Composition of the secretion from the eccrine sweat glands of the cat's foot pad.

    Science.gov (United States)

    Foster, K G

    1966-05-01

    1. The sweat composition from the cat's foot pad was examined at various rates of secretion. Sodium pentobarbitone or chloralose anaesthesia were used.2. Cat's pad sweat contains lactate, glucose is almost absent, and the sodium and chloride concentrations increased with increasing sweat rate. In these respects the secretion resembles human eccrine sweat.3. The sodium, chloride, and potassium concentrations are much higher than in human sweat; also the potassium level decreased with increasing rate. Consequently, whereas human sweat is hypotonic with respect to the plasma, cat's pad sweat is slightly hypertonic with respect to the plasma even at low rates of secretion. In contrast to human sweat glands, which produce a slightly acidic secretion containing ammonia, cat's pad sweat glands produce an alkaline secretion containing bicarbonate. Also in contrast to human sweat, lactate levels decreased with increasing sweat rate.

  6. Artificial sweat composition to grow and sustain a mixed human axillary microbiome.

    Science.gov (United States)

    Callewaert, Chris; Buysschaert, Benjamin; Vossen, Els; Fievez, Veerle; Van de Wiele, Tom; Boon, Nico

    2014-08-01

    A novel artificial sweat composition, Skin Community Interaction simulation, designed to mimic the human axillary sweat, was compared to other artificial sweat compositions. Axillary microbiota grown in the novel composition closely resembled the original community. Volatile organic compound analysis showed good correlations with in vivo axillary (mal)odor components. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Composite solid polymer electrolyte membranes

    Science.gov (United States)

    Formato, Richard M.; Kovar, Robert F.; Osenar, Paul; Landrau, Nelson; Rubin, Leslie S.

    2006-05-30

    The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.

  8. Composite solid polymer electrolyte membranes

    Science.gov (United States)

    Formato, Richard M.; Kovar, Robert F.; Osenar, Paul; Landrau, Nelson; Rubin, Leslie S.

    2001-06-19

    The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.

  9. Effect of induced metabolic alkalosis on sweat composition in men.

    Science.gov (United States)

    Patterson, M J; Galloway, Stuart D R; Nimmo, M A

    2002-01-01

    To determine whether induced metabolic alkalosis affects sweat composition, 10 males cycled for 90 min at 62.5 +/- 1.3% peak oxygen uptake, on two separate occasions. Subjects ingested either empty capsules (placebo) or capsules containing NaHCO3- (0.3 g kg-1 body mass; six equal doses) over a 2-h period, which commenced 3 h prior to exercise. Arterialized-venous blood samples were drawn prior to and after 15, 30, 60 and 90 min of exercise. Sweat was aspirated at the end of exercise from a patch located on the right scapula region. NaHCO3- ingestion elevated blood pH, [HCO3-] and serum [Na+], whereas serum [Cl-] and [K+] were reduced, both at rest and during exercise (P Sweat pH was greater in the NaHCO3- trial (6.24 +/- 0.18 vs. 6.38 +/- 0.18; P sweat [Na+] (49.5 +/- 4.8 vs. 50.2 +/- 4.3 mEq L-1), [Cl-] (37.5 +/- 5.1 vs. 39.3 +/- 4.2 mEq L-1) and [K+] (4.66 +/- 0.19 vs. 4.64 +/- 0.34 mEq L-1) did not differ between trials (P > 0.05). Sweat [HCO3-] (2.49 +/- 0.58 vs. 3.73 +/- 1.10 mEq L-1) and [lactate] (8.92 +/- 0.79 vs. 10.51 +/- 0.32 mmol L-1) tended to be greater after NaHCO3- ingestion, although significance was not reached (P=0.07 and P=0.08, respectively). These data indicate that induced metabolic alkalosis can modify sweat composition, although it is unclear whether the secretory coil, reabsorptive duct, or both are responsible for this alteration.

  10. [Analysis of fatty acid composition of sweat lipids in children and adults with skin disease].

    Science.gov (United States)

    Andrashko, Iu V; Koliadenko, V G; Briuzgina, T S; Prokhorova, M P

    2002-01-01

    Gas-chromatographic analysis of fatty acid composition of sweat lipids in children and adults with neurodermatitis, atopic dermatitis, and eczema showed that sweat can be used as a new noninvasive biological object for evaluation of lipid metabolism disorders.

  11. Indirect measurements of sweat electrolyte concentration in the laboratory diagnosis of cystic fibrosis

    Science.gov (United States)

    Heeley, M.; Woolf, D.; Heeley, A.

    2000-01-01

    AIM—To investigate whether analytical methods based on the colligative physical chemical properties of ions or solutes in sweat are less effective than the specific measurement of electrolytes in the diagnosis of cystic fibrosis (CF).
METHODS—A single sweat sample was collected (Macroduct) from each of 211 infants and children, of whom 57 had CF, for the measurment of sodium, chloride, osmolality, and conductivity.
RESULTS—The ranges within which CF and non-CF individual values overlapped (equivocal ranges), were wider for sodium and osmolality measurement than for chloride or conductivity. Neither of the latter two measurements provided a discriminatory advantage over the other. The utilisation of broadly based age related ranges for non-CF control subjects served to improve the discriminatory power of all four measurements to an extent that, in this cohort, both chloride and conductivity provided complete discrimination.
CONCLUSION—Sweat conductivity is as effective as chloride measurement in the laboratory diagnosis of CF.

 PMID:10799439

  12. Effects of short-term exercise in the heat on thermoregulation, blood parameters, sweat secretion and sweat composition of tropic-dwelling subjects.

    Science.gov (United States)

    Saat, Mohamed; Sirisinghe, Roland Gamini; Singh, Rabindarjeet; Tochihara, Yutaka

    2005-09-01

    This study investigates the effects of a short-term aerobic training program in a hot environment on thermoregulation, blood parameters, sweat secretion and composition in tropic-dwellers who have been exposed to passive heat. Sixteen healthy Malaysian-Malay male volunteers underwent heat acclimation (HA) by exercising on a bicycle ergometer at 60% of VO2max for 60 min each day in a hot environment (Ta: 31.1+/-0.1 degrees C, rh: 70.0+/-4.4%) for 14 days. All parameters mentioned above were recorded on Day 1 and at the end of HA (Day 16). On these two days, subjects rested for 10 min, then cycled at 60% of VO2max for 60 min and rested again for 20 min (recovery) in an improvised heat chamber. Rectal temperature (Tre), mean skin temperature (Tsk) heart rate (HR), ratings of perceived exertion (RPE), thermal sensation (TS), local sweat rate and percent dehydration were recorded during the test. Sweat concentration was analysed for sodium [Na+]sweat and potassium. Blood samples were analysed for biochemical changes, electrolytes and hematologic indices. Urine samples were collected before and after each test and analysed for electrolytes.After the period of acclimation the percent dehydration during exercise significantly increased from 1.77+/-0.09% (Day 1) to 2.14+/-0.07% (Day 16). Resting levels of hemoglobin, hematocrit and red blood cells decreased significantly while [Na+]sweat increased significantly. For Tre and Tsk there were no differences at rest. Tre, HR, RPE, TS, plasma lactate concentration, hemoglobin and hematocrit at the 40th min of exercise were significantly lower after the period of acclimation but mean corpuscular hemoglobin and serum osmolality were significantly higher while no difference was seen in [Na+]sweat and Tsk. It can be concluded that tropic-dwelling subjects, although exposed to prolonged passive heat exposure, were not fully heat acclimatized. To achieve further HA, they should gradually expose themselves to exercise-heat stress in a

  13. Ionic mechanisms of Ca(2+)-dependent electrolyte transport across equine sweat gland epithelium.

    Science.gov (United States)

    Ko, W H; Chan, H C; Chew, S B; Wong, P Y

    1996-01-01

    1. The ionic mechanism involved in Ca(2+)-stimulated electrolyte transport in cultured equine sweat gland epithelial cells was studied using the short-circuit current (ISC) technique. 2. Microscopy revealed that the cultured cells grown on Millipore filters formed polarized monolayers with tight junctions. Monolayers exhibited a mean transepithelial resistance of 333.9 +/- 40.4 omega cm2. 3. Ca(2+)-mobilizing agents, A23187 (1 microM) or thapsigargin (0.01-1 microM), stimulated ISC while forskolin exerted little effect on the ISC. 4. Replacement of external Cl- by gluconate significantly reduced the ISC by 63% when stimulated by 0.1 microM thapsigargin. Residual ISC could be abolished (> 99%) by elimination of HCO3- from the bathing solution. 5. Basolateral addition of bumetanide (0.1 mM), ouabain (0.01 mM) and acetazolamide (45 microM) and apical addition of methyl isobutyl amiloride (MIA, 1-100 microM) all had inhibitory effects on the thapsigargin-stimulated ISC to various extents. 6. Substantial current inhibition could be obtained using 4, 4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) and diphenylamine-2-carboxylate (DPC) in a concentration-dependent manner. 7. The K+ channel blocker barium (5 mM) was effective on both sides of the epithelium with a much larger effect on the basolateral side. 8. The inhibitory effects of acetazolamide, amiloride, MIA, DIDS and DPC on the thapsigargin-stimulated ISC were also observed when a Cl(-)-free solution was used. 9. The results provide evidence for Ca(2+)-stimulated HCO3- as well as Cl- secretion by equine sweat gland epithelium. Images Figure 1 PMID:8799908

  14. Sweating Rate and Sweat Sodium Concentration in Athletes: A Review of Methodology and Intra/Interindividual Variability.

    Science.gov (United States)

    Baker, Lindsay B

    2017-03-01

    Athletes lose water and electrolytes as a consequence of thermoregulatory sweating during exercise and it is well known that the rate and composition of sweat loss can vary considerably within and among individuals. Many scientists and practitioners conduct sweat tests to determine sweat water and electrolyte losses of athletes during practice and competition. The information gleaned from sweat testing is often used to guide personalized fluid and electrolyte replacement recommendations for athletes; however, unstandardized methodological practices and challenging field conditions can produce inconsistent/inaccurate results. The primary objective of this paper is to provide a review of the literature regarding the effect of laboratory and field sweat-testing methodological variations on sweating rate (SR) and sweat composition (primarily sodium concentration [Na + ]). The simplest and most accurate method to assess whole-body SR is via changes in body mass during exercise; however, potential confounding factors to consider are non-sweat sources of mass change and trapped sweat in clothing. In addition, variability in sweat [Na + ] can result from differences in the type of collection system used (whole body or localized), the timing/duration of sweat collection, skin cleaning procedure, sample storage/handling, and analytical technique. Another aim of this paper is to briefly review factors that may impact intra/interindividual variability in SR and sweat [Na + ] during exercise, including exercise intensity, environmental conditions, heat acclimation, aerobic capacity, body size/composition, wearing of protective equipment, sex, maturation, aging, diet, and/or hydration status. In summary, sweat testing can be a useful tool to estimate athletes' SR and sweat Na + loss to help guide fluid/electrolyte replacement strategies, provided that data are collected, analyzed, and interpreted appropriately.

  15. Acute effects of dehydration on sweat composition in men during prolonged exercise in the heat.

    Science.gov (United States)

    Morgan, R M; Patterson, M J; Nimmo, M A

    2004-09-01

    To determine whether acute exercise-heat-induced dehydration affects sweat composition, eight males cycled for 2 h at 39.5 +/- 1.6% VO2peak on two separate occasions in a hot-humid environment (38.0 +/- 0.0 degrees C, 60.0 +/- 0.1% relative humidity). During exercise, subjects ingested either no fluid (dehydration) or a 20 mmol L(-1) sodium chloride solution (euhydration). The volume of solution, calculated from whole-body sweat loss and determined in a familiarization trial, was ingested at 0 min and every 15 min thereafter. Venous blood was collected at 0, 60 and 120 min of exercise and sweat was aspirated from a patch located on the dominant forearm at 120 min. Following the 2-h cycling exercise, sweat [Na+] and [Cl-] was greater (P sweat [Na+] and [Cl-] which was potentially related to greater extracellular fluid [Na+], plasma aldosterone or sympathetic nervous activity.

  16. System-level design of an RFID sweat electrolyte sensor patch.

    Science.gov (United States)

    Rose, Daniel P; Ratterman, M; Griffin, Daniel K; Hou, Linlin; Kelley-Loughnane, Nancy; Naik, Rajesh K; Hagen, Joshua A; Papautsky, I; Heikenfeld, Jason

    2014-01-01

    Wearable digital health devices are dominantly found in rigid form factors such as bracelets and pucks. An adhesive RFID sensor bandage (patch) is reported, which can be made completely intimate with human skin, a distinct advantage for chronological monitoring of biomarkers in sweat. In this demonstration, a commercial RFID chip is adapted with minimum components to allow potentiometric sensing of mM ionic solutes in sweat, and surface temperature, as read by an Android smart-phone app (in-vitro tests).

  17. Rate and composition of sweat fluid losses are unaltered by hypohydration during prolonged exercise in horses.

    Science.gov (United States)

    Kingston, J K; Geor, R J; McCutcheon, L J

    1997-10-01

    Rate and ionic composition of sweat fluid losses and partitioning of evaporative heat loss into respiratory and cutaneous components were determined in six horses during three 15-km phases of exercise at approximately 40% of maximal O2 uptake. Pattern of change in sweat rate (SR) and composition was similar during each phase. SR increased rapidly for the first 20 min of exercise but remained at approximately 24-28 ml . m-2 . min-1 during the remainder of each phase. Similarly, the concentrations of Na and Cl in sweat increased until 30 min of exercise but were unchanged thereafter. Sweat osmolality and concentrations of Na and Cl were positively correlated with SR. Sweat K concentration decreased during exercise but was not correlated with SR. Fluid losses were 33.8 +/- 1.5 liters, resulting in decreases of approximately 21% in plasma volume and approximately 11% in total body water. The approximately 6% hypohydration was not associated with an alteration in SR, sweat composition, or heat storage. Respiratory and cutaneous evaporative heat loss represented approximately 23 and 70%, respectively, of the total heat dissipated, and the partitioning of heat loss was similar in each exercise phase. We conclude that SR and the relative proportions of respiratory and cutaneous evaporative heat loss are unchanged in horses during prolonged low-intensity exercise despite moderate hypohydration.

  18. Amino acid composition, including key derivatives of eccrine sweat: potential biomarkers of certain atopic skin conditions.

    Science.gov (United States)

    Mark, Harker; Harding, Clive R

    2013-04-01

    The free amino acid (AA) composition of eccrine sweat is different from other biological fluids, for reasons which are not properly understood. We undertook the detailed analysis of the AA composition of freshly isolated pure human eccrine sweat, including some of the key derivatives of AA metabolism, to better understand the key biological mechanisms governing its composition. Eccrine sweat was collected from the axillae of 12 healthy subjects immediately upon formation. Free AA analysis was performed using an automatic AA analyser after ninhydrin derivatization. Pyrrolidine-5-carboxylic acid (PCA) and urocanic acid (UCA) levels were determined using GC/MS. The free AA composition of sweat was dominated by the presence of serine accounting for just over one-fifth of the total free AA composition. Glycine was the next most abundant followed by PCA, alanine, citrulline and threonine, respectively. The data obtained indicate that the AA content of sweat bears a remarkable similarity to the AA composition of the epidermal protein profilaggrin. This protein is the key source of free AAs and their derivatives that form a major part of the natural moisturizing factor (NMF) within the stratum corneum (SC) and plays a major role in maintaining the barrier integrity of human skin. As perturbations in the production of NMF can lead to abnormal barrier function and can arise as a consequence of filaggrin genotype, we propose the quantification of AAs in sweat may serve as a non-invasive diagnostic biomarker for certain atopic skin conditions, that is, atopic dermatitis (AD). © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  19. Anti-perovskite solid electrolyte compositions

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yusheng; Daemen, Luc Louis

    2015-12-26

    Solid electrolyte antiperovskite compositions for batteries, capacitors, and other electrochemical devices have chemical formula Li.sub.3OA, Li.sub.(3-x)M.sub.x/2OA, Li.sub.(3-x)N.sub.x/3OA, or LiCOX.sub.zY.sub.(1-z), wherein M and N are divalent and trivalent metals respectively and wherein A is a halide or mixture of halides, and X and Y are halides.

  20. On-ice sweat rate, voluntary fluid intake, and sodium balance during practice in male junior ice hockey players drinking water or a carbohydrate-electrolyte solution.

    Science.gov (United States)

    Palmer, Matthew S; Logan, Heather M; Spriet, Lawrence L

    2010-06-01

    This study evaluated the repeatability of hydration and sweat measurements taken during on-ice hockey practices with players drinking only water, and determined whether having only a carbohydrate-electrolyte solution (CES) to drink during practices decreased fluid intake or affected other hydration and (or) sweat measures. All testing was conducted on elite players of an Ontario Hockey League team (+/-SE; mean age, 17.6 +/- 0.3 years; mean height, 182.9 +/- 1.4 cm; mean body mass, 83.0 +/- 1.7 kg). Players were studied 3 times over the course of 6 weekly on-ice practices (+/-SE; mean playing time, 1.58 +/- 0.07 h; mean temperature, 11.4 +/- 0.8 degrees C; mean relative humidity, 52% +/- 3%). There was strong repeatability of the measured hydration and sweat parameters between 2 similar on-ice practices when players drank only water. Limiting the players to drinking only a CES (as opposed to water) did not decrease fluid intake during practice (+/-SE; mean CES intake, 0.72 +/- 0.07 L.h-1 vs. mean water intake, 0.82 +/- 0.08 L.h-1) or affect sweat rate (1.5 +/- 0.1 L.h-1 vs. 1.5 +/- 0.1 L.h-1), sweat sodium concentration (72.4 +/- 5.6 mmol.L-1 vs. 73.0 +/- 4.4 mmol.L-1), or percent body mass loss (1.1% +/- 0.2% vs. 0.9% +/- 0.2%). Drinking a CES also improved sodium balance (-2.1 +/- 0.2 g.h-1 vs. -2.6 +/- 0.3 g.h-1) and provided the players with a significant carbohydrate (43 +/- 4 g.h-1 vs. 0 +/- 0 g.h-1) during practice. In summary, a single field sweat test during similar on-ice hockey practices in male junior hockey players is sufficient to evaluate fluid and electrolyte balance. Also, a CES does not affect voluntary fluid intake during practice, compared with water, in these players. The CES provided some salt to offset the salt lost in sweat, and carbohydrate, which may help maintain physical and mental performance in the later stages of practice.

  1. What's Sweat?

    Science.gov (United States)

    ... Weight for Me? Your Teeth Heart Murmurs What's Sweat? KidsHealth > For Kids > What's Sweat? Print A A ... dehydrated (say: dee-HI-drayt-ed). Why Does Sweat Smell? Sweat isn't just wet — it can ...

  2. Nanoduct Sweat Conductivity Measurements in 2664 Patients: Relationship to Age, Arterial Blood Gas, Serum Electrolyte Profiles and Clinical Diagnosis

    Science.gov (United States)

    Sezer, Rabia Gonul; Aydemir, Gokhan; Akcan, Abdullah Baris; Paketci, Cem; Karaoglu, Abdulbaki; Aydinoz, Secil; Bozaykut, Abdulkadir

    2013-01-01

    Background The Nanoduct® device has acceptable diagnostic accuracy, but there is not enough systematic data supporting its usage in the diagnosis of cystic fibrosis (CF). Methods A retrospective review of patients with an indication for the sweat test was conducted. The conductivity test was repeated in patients who had values higher than 60 mmol/L, and they were referred for sweat chloride measurements. Associations between sweat conductivity measurements and age, gender, (pH, HCO3, pCO2, Na, K, Cl), family history, consanguinity, indications for the test and number of hospitalization were studied. Results Among 2,664 patients, 16 children had sweat conductivity values higher than 80. The median age of patients diagnosed with CF was 4 months old. Age, pH, HCO3, Na, Cl, K and the sweat conductivity test were statistically related (P conductivity test and the sweat test. Conclusions Patients suspected to have CF can be screened using the Nanoduct® conductivity device in non-qualified centers. PMID:23390474

  3. Night Sweats

    Science.gov (United States)

    Symptoms Night sweats By Mayo Clinic Staff Night sweats are repeated episodes of extreme perspiration that may soak your nightclothes or ... these episodes are usually not labeled as night sweats and typically aren't a sign of a ...

  4. Solid polymer electrolyte composite membrane comprising laser micromachined porous support

    Science.gov (United States)

    Liu, Han [Waltham, MA; LaConti, Anthony B [Lynnfield, MA; Mittelsteadt, Cortney K [Natick, MA; McCallum, Thomas J [Ashland, MA

    2011-01-11

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 5 microns, are made by laser micromachining and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  5. Composition and particle size of electrolytic copper powders prepared in water-containing dimethyl sulfoxide electrolytes

    Science.gov (United States)

    Mamyrbekova, Aigul'; Abzhalov, B. S.; Mamyrbekova, Aizhan

    2017-07-01

    The possibility of the electroprecipitation of copper powder via the cathodic reduction of an electrolyte solution containing copper(II) nitrate trihydrate and dimethyl sulfoxide (DMSO) is shown. The effect electrolysis conditions (current density, concentration and temperature of electrolyte) have on the dimensional characteristics of copper powder is studied. The size and shape of the particles of the powders were determined by means of electron microscopy; the qualitative composition of the powders, with X-ray diffraction.

  6. Volume and composition of hand sweat of White and Black men and women in desert walks.

    Science.gov (United States)

    Dill, D B; Yousef, M K; Goldman, A; Hillyard, S D; Davis, T P

    1983-05-01

    Many investigators have sought, but failed to find, ethnic differences in the number and regional distribution of active sweat glands. In this study measurements have been made of sweat secreted on one hand and also on the whole body of Whites and Blacks walking in desert heat. Whites numbered 31 men and 27 women, ages 30 to 88 years; there were 21 Black men and 31 Black women, ages 16 to 61 years. Each walked on three occasions for 1 hour at a rate that required an oxygen consumption of about 40% of aerobic capacity. Ambient temperature ranged from 32 to 44 degrees C in 1979 and 1980; means were 38.4 degrees C in 1979 and 36.7 degrees C in 1980. There was no sweat in the gloves of many Blacks; this was true of only a few Whites. Volume of body sweat increased in both races with rate of walking; volume of hand sweat increased more in Whites than in Blacks. The Mann-Whitney test revealed that volumes of hand sweat were significantly greater for Whites than for Blacks. It was concluded that in desert walks most Whites and few Blacks sweat freely on their hands. In samples of hand sweat, Na+, K+, and Cl- were determined. Concentrations of each ion varied widely in both races, and were unrelated to race. Concentrations of Na+ and Cl- generally are somewhat higher in hand sweat than in body sweat; concentrations of K+ are much higher. It follows that the values for concentration of Na+ and Cl- reported in Table 3 probably are somewhat higher than would have been found in body sweat, and concentrations of K+ are probably much higher.

  7. Human Water and Electrolyte Balance

    National Research Council Canada - National Science Library

    Montain, S. J; Cheuvront, S. N; Carter, R; Sawka, M. N

    2006-01-01

    .... Sweat losses, if not replaced, reduce body water volume and electrolyte content. Excessive body water or electrolyte losses can disrupt physiological homeostasis and threaten both health and performance...

  8. EFFECT OF MULTIPARITY ON ELECTROLYTE COMPOSITION ...

    African Journals Online (AJOL)

    Daniel Owu

    Summary: Pregnancy affects the physiology of the pregnant woman particularly the endocrine, cardiovascular and the renal systems. This work was therefore set to ascertain the state of electrolytes in pregnancy and how it affects blood pressure using multiparity as a factor. One hundred and twenty (120) women were used ...

  9. Sweat Therapy.

    Science.gov (United States)

    Colmant, Stephen A.; Merta, Rod J.

    2000-01-01

    A study combined group sweating and group counseling. Four adolescent boys with disruptive behavior disorders participated in 12 sweat therapy sessions. They reported the sessions useful for sharing personal concerns and receiving assistance with problem solving. Three boys showed improvement in self-esteem. Advantages of sweat therapy over other…

  10. Sweat mechanisms and dysfunctions in atopic dermatitis.

    Science.gov (United States)

    Hendricks, Aleksi J; Vaughn, Alexandra R; Clark, Ashley K; Yosipovitch, Gil; Shi, Vivian Y

    2018-02-01

    Skin barrier dysfunction is inherent to atopic dermatitis (AD), causing dryness, irritation, and increased permeability to irritants, allergens and pathogens. Eccrine sweat functions as part of the skin's protective barrier. Variations in sweat responses have been observed in patients with AD, and altered sweat composition and dynamics are under-recognized as important factors in the disease cycle. This review discusses the role that sweat plays in the pathogenesis of AD, examines evidence on abnormal sweat composition, secretion, and neuro-immune responses to sweat in atopic skin, and highlights the value of sweat management. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

  11. Solid polymer electrolyte composite membrane comprising plasma etched porous support

    Science.gov (United States)

    Liu, Han; LaConti, Anthony B.

    2010-10-05

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  12. Alkoxide-based magnesium electrolyte compositions for magnesium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Sheng; Sun, Xiao-Guang; Liao, Chen; Guo, Bingkun

    2018-01-30

    Alkoxide magnesium halide compounds having the formula: RO--Mg--X (1) wherein R is a saturated or unsaturated hydrocarbon group that is unsubstituted, or alternatively, substituted with one or more heteroatom linkers and/or one or more heteroatom-containing groups comprising at least one heteroatom selected from fluorine, nitrogen, oxygen, sulfur, and silicon; and X is a halide atom. Also described are electrolyte compositions containing a compound of Formula (1) in a suitable polar aprotic or ionic solvent, as well as magnesium batteries in which such electrolytes are incorporated.

  13. [The fatty acid composition of the lipids in the sweat of patients with complications in the acute period of a myocardial infarct].

    Science.gov (United States)

    Gichka, S G; Briuzgina, T S; Reva, S N

    1998-06-01

    Sweat lipids fatty acid (FA) composition was determined in patients presenting with uncomplicated course of acute myocardial infarction and in the development of pulmonary edema and pneumonia with the aid of a gas-chromatographic technique. The development in the patients of pulmonary complications was found out to be accompanied by a substantial elevation of sweat lipids content of polyunsaturated FA, linoleic and arachidonic FA in particular, which fact can be taken as a diagnostic and prognostic criterion.

  14. Rice-based electrolyte drinks more effective than water in replacing sweat losses during hot weather training and operations.

    Science.gov (United States)

    Gerold, Kevin B; Greenough, William B

    2013-01-01

    Heat-related injury presents significant threats to the health and operational effectiveness of Soldiers and military operations. In 2012, active component, U.S. Armed Forces experienced 365 incident cases of heat stroke and 2,257 incident cases of ?other heat injury.? Most of these occurred among recruit and enlisted personnel and most were under the age of 30. In conditioned military personnel, a rice-based oral rehydration solution was superior to water alone at maintaining body weight and, by inference, enabled Soldiers to better maintain their the state of hydration during prolonged exercise in high ambient temperatures. In view of the health risks associated with dehydration and their effects on training and operations, this study suggests that the consumption of beverages containing electrolytes and a rice-based carbohydrate is superior to the consumption of water alone in preventing dehydration and heat related illness. 2013.

  15. Phase composition of perlite steel modified by electrolyte plasma nitriding

    Science.gov (United States)

    Popova, Natalya; Erygina, Lyudmila; Nikonenko, Elena; Skakov, Mazhin

    2017-11-01

    The paper presents the transmission electron microscopy (TEM) investigations of phase composition of the type 0.34C-1Cr-1Ni-1Mo-Fe steel after the modification by electrolyte plasma nitriding performed in a nitrogen aqueous solution for 5 min and under voltage of 600 V. Two states of the steel specimens are investigated: 1) before nitriding (original state) and 2) after nitriding the specimen surface layer. TEM investigations show that electrolyte plasma nitriding results in substantial structural modifications such as phase composition and the number of phases involved. In the original state, the specimen structure represents lamellar perlite, ferritic-carbide mix, and fragmented ferrite. After electrolyte plasma nitriding, the structure is lamellar non-fragmented perlite and fragmented ferrite. The former is present in three states, namely: ideal lamellar perlite, lamellar perlite with fractured cementite laminae, and defect lamellar perlite. The particles of alloyed cementite M3C and nitride Fe3Mo3N are observed in each state. The structure of fragmented ferrite contains the particles of nitride Fe3Mo3N, carbonitride Cr2C0.61N0.39 and alloyed cementite M3C. The investigation also determines that electrolyte plasma nitriding leads to the increase in scalar density of dislocations in α-matrix and long-range (internal) plastic stresses.

  16. Sweat Facilitated Amino Acid Losses in Male Athletes during Exercise at 32-34°C.

    Science.gov (United States)

    Dunstan, R Hugh; Sparkes, Diane L; Dascombe, Benjamin J; Macdonald, Margaret M; Evans, Craig A; Stevens, Christopher J; Crompton, Marcus J; Gottfries, Johan; Franks, Jesse; Murphy, Grace; Wood, Ryan; Roberts, Timothy K

    2016-01-01

    Sweat contains amino acids and electrolytes derived from plasma and athletes can lose 1-2L of sweat per hour during exercise. Sweat may also contain contributions of amino acids as well as urea, sodium and potassium from the natural moisturizing factors (NMF) produced in the stratum corneum. In preliminary experiments, one participant was tested on three separate occasions to compare sweat composition with surface water washings from the same area of skin to assess contributions from NMF. Two participants performed a 40 minute self-paced cycle session with sweat collected from cleansed skin at regular intervals to assess the contributions to the sweat load from NMF over the period of exercise. The main study investigated sweat amino acid composition collected from nineteen male athletes following standardised endurance exercise regimes at 32-34°C and 20-30% RH. Plasma was also collected from ten of the athletes to compare sweat and plasma composition of amino acids. The amino acid profiles of the skin washings were similar to the sweat, suggesting that the NMF could contribute certain amino acids into sweat. Since the sweat collected from athletes contained some amino acid contributions from the skin, this fluid was subsequently referred to as "faux" sweat. Samples taken over 40 minutes of exercise showed that these contributions diminished over time and were minimal at 35 minutes. In the main study, the faux sweat samples collected from the athletes with minimal NMF contributions, were characterised by relatively high levels of serine, histidine, ornithine, glycine and alanine compared with the corresponding levels measured in the plasma. Aspartic acid was detected in faux sweat but not in the plasma. Glutamine and proline were lower in the faux sweat than plasma in all the athletes. Three phenotypic groups of athletes were defined based on faux sweat volumes and composition profiles of amino acids with varying relative abundances of histidine, serine, glycine

  17. Sweat Facilitated Amino Acid Losses in Male Athletes during Exercise at 32-34°C.

    Directory of Open Access Journals (Sweden)

    R Hugh Dunstan

    Full Text Available Sweat contains amino acids and electrolytes derived from plasma and athletes can lose 1-2L of sweat per hour during exercise. Sweat may also contain contributions of amino acids as well as urea, sodium and potassium from the natural moisturizing factors (NMF produced in the stratum corneum. In preliminary experiments, one participant was tested on three separate occasions to compare sweat composition with surface water washings from the same area of skin to assess contributions from NMF. Two participants performed a 40 minute self-paced cycle session with sweat collected from cleansed skin at regular intervals to assess the contributions to the sweat load from NMF over the period of exercise. The main study investigated sweat amino acid composition collected from nineteen male athletes following standardised endurance exercise regimes at 32-34°C and 20-30% RH. Plasma was also collected from ten of the athletes to compare sweat and plasma composition of amino acids. The amino acid profiles of the skin washings were similar to the sweat, suggesting that the NMF could contribute certain amino acids into sweat. Since the sweat collected from athletes contained some amino acid contributions from the skin, this fluid was subsequently referred to as "faux" sweat. Samples taken over 40 minutes of exercise showed that these contributions diminished over time and were minimal at 35 minutes. In the main study, the faux sweat samples collected from the athletes with minimal NMF contributions, were characterised by relatively high levels of serine, histidine, ornithine, glycine and alanine compared with the corresponding levels measured in the plasma. Aspartic acid was detected in faux sweat but not in the plasma. Glutamine and proline were lower in the faux sweat than plasma in all the athletes. Three phenotypic groups of athletes were defined based on faux sweat volumes and composition profiles of amino acids with varying relative abundances of histidine

  18. Nanoporous Polymer-Ceramic Composite Electrolytes for Lithium Metal Batteries

    KAUST Repository

    Tu, Zhengyuan

    2013-09-16

    A nanoporous composite material that offers the unique combination of high room-temperature ionic conductivity and high mechanical modulus is reported. When used as the separator/electrolyte in lithium batteries employing metallic lithium as anode, the material displays unprecedented cycling stability and excellent ability to prevent premature cell failure by dendrite-induced short circuits © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Composite Polymer Electrolytes: Nanoparticles Affect Structure and Properties

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2016-11-01

    Full Text Available Composite polymer electrolytes (CPEs can significantly improve the performance in electrochemical devices such as lithium-ion batteries. This review summarizes property/performance relationships in the case where nanoparticles are introduced to polymer electrolytes. It is the aim of this review to provide a knowledge network that elucidates the role of nano-additives in the CPEs. Central to the discussion is the impact on the CPE performance of properties such as crystalline/amorphous structure, dielectric behavior, and interactions within the CPE. The amorphous domains of semi-crystalline polymer facilitate the ion transport, while an enhanced mobility of polymer chains contributes to high ionic conductivity. Dielectric properties reflect the relaxation behavior of polymer chains as an important factor in ion conduction. Further, the dielectric constant (ε determines the capability of the polymer to dissolve salt. The atom/ion/nanoparticle interactions within CPEs suggest ways to enhance the CPE conductivity by generating more free lithium ions. Certain properties can be improved simultaneously by nanoparticle addition in order to optimize the overall performance of the electrolyte. The effects of nano-additives on thermal and mechanical properties of CPEs are also presented in order to evaluate the electrolyte competence for lithium-ion battery applications.

  20. Geometry and Composition of Interstitial Fluids in Frozen Electrolyte Solutions

    Science.gov (United States)

    Cheng, J.; Colussi, A. J.; Hoffmann, M. R.

    2009-12-01

    The composition and morphology of the fluid microchannels threading polycrystaline ice affects the integrity of ice core records and the strength of ice-atmosphere interactions. These fluids owe their existence to impurities and curvature depression. Electrolyte impurities induce bulk colligative effects, but also charge ice surfaces, while screening the resulting electrostatic repulsion. A non-monotonic rather than positive dependence of channel width δ on electrolyte concentration has thus been predicted. Herein we report the first time-resolved, confocal microscopy study of freezing water and electrolyte solutions doped with 10 μM of C-SNARF-1, a fluorescent pH probe. The freezing of doped water concentrates the probe into discrete δ = (12 ± 2) μm channels embedded in pristine ice, whereas ice fronts advancing (at < 5 μm/s) into 1 mM electrolytes destabilize and engulf them into < 1 μm fluid occlusions distributed over the sample. These findings are consistent with a non-monotonic dependence of δ on ion concentration. pH increases by less than 0.4 unit within the occlusions formed in freezing NaCl solutions, and by over 1 unit upon subsequent thawing, revealing that hydroxide ion slowly produced via the dissociation of water molecule in ice seeps from ice to relieve the excess charge generated by chloride inclusion. In contrast, the preferential incorporation of the ammonium ions over the acetate anions into ice leads to the acidification of partially frozen ammonium acetate solutions.

  1. Sweat Allergy.

    Science.gov (United States)

    Hiragun, Takaaki; Hide, Michihiro

    2016-01-01

    For many years, sweat has been recognized as an exacerbation factor in all age groups of atopic dermatitis (AD) and a trigger of cholinergic urticaria (CholU). Recently, we reported the improvement of AD symptoms by spray with tannic acid, which suppresses basophil histamine release by semipurified sweat antigens in vitro, and showering that removes antigens in sweat from the skin surface. We finally identified MGL_1304 secreted by Malassezia globosa as a major histamine-releasing antigen in human sweat. MGL_1304 is detected as a 17-kDa protein in sweat and exhibits almost the highest histamine-release ability from basophils of patients with AD and CholU among antigens derived from Malassezia species. Moreover, serum levels of anti-MGL_1304 IgE of patients with AD and CholU were significantly higher than those of normal controls. Desensitization therapy using autologous sweat or MGL_1304 purified from culture of M. globosa or its cognates might be beneficial for patients with intractable CholU due to sweat allergy. © 2016 S. Karger AG, Basel.

  2. Working Up a Good Sweat - The Challenges of Standardising Sweat Collection for Metabolomics Analysis.

    Science.gov (United States)

    Hussain, Joy N; Mantri, Nitin; Cohen, Marc M

    2017-02-01

    Human sweat is a complex biofluid of interest to diverse scientific fields. Metabolomics analysis of sweat promises to improve screening, diagnosis and self-monitoring of numerous conditions through new applications and greater personalisation of medical interventions. Before these applications can be fully developed, existing methods for the collection, handling, processing and storage of human sweat need to be revised. This review presents a cross-disciplinary overview of the origins, composition, physical characteristics and functional roles of human sweat, and explores the factors involved in standardising sweat collection for metabolomics analysis. A literature review of human sweat analysis over the past 10 years (2006-2016) was performed to identify studies with metabolomics or similarly applicable 'omics' analysis. These studies were reviewed with attention to sweat induction and sampling techniques, timing of sweat collection, sweat storage conditions, laboratory derivation, processing and analytical platforms. Comparative analysis of 20 studies revealed numerous factors that can significantly impact the validity, reliability and reproducibility of sweat analysis including: anatomical site of sweat sampling, skin integrity and preparation; temperature and humidity at the sweat collection sites; timing and nature of sweat collection; metabolic quenching; transport and storage; qualitative and quantitative measurements of the skin microbiota at sweat collection sites; and individual variables such as diet, emotional state, metabolic conditions, pharmaceutical, recreational drug and supplement use. Further development of standard operating protocols for human sweat collection can open the way for sweat metabolomics to significantly add to our understanding of human physiology in health and disease.

  3. [The dynamic changes in the fatty acid composition of the sweat from patients in the acute period of a myocardial infarct].

    Science.gov (United States)

    Gichka, S G; Briuzgina, T S; Reva, S N

    1998-01-01

    Sweat lipids higher fatty acid composition was measured in patients in the time course of myocardial infarction development using a gas-chromatography technique. Within 2-4 days of the onset of myocardial infarction running a complicated course sweat lipids total polyunsaturated fatty acids have gotten strikingly increased (by 700% versus control) at the expense of linoleic acid (a rise by 300%) and arachidonic acid (an increase by 400%), which fact can be relied upon in prognostication and early diagnosis of pulmonary edema and pneumonia.

  4. Metal ion release and surface composition of the Cu 18Ni 20Zn nickel silver during 30 days immersion in artificial sweat

    Science.gov (United States)

    Milošev, Ingrid; Kosec, Tadeja

    2007-11-01

    In order to study nickel ion release associated with nickel allergy, Cu-18Ni-20Zn nickel-silver alloy was immersed in artificial sweat and Ringer physiological solution for 30 days. Dissolution of metal ions was measured as a function of time, and the characteristics of the solid surface layer formed after 30 days were studied by SEM/EDS and XPS. The dissolution of nickel prevails over dissolution of copper and zinc. Nickel release in artificial sweat is approximately 10 times higher than in Ringer physiological solution and in both solutions the nickel release exceeds 0.5 μg cm -2 week -1, the threshold above which the allergy is triggered. Evidence of selective nickel dissolution is reported. The composition of the surface layer formed in artificial sweat and in Ringer physiological solution differs in the content of nickel and chlorine. In artificial sweat, the major constituents of the surface layer are dominantly oxides, Cu 2O and ZnO, with traces of chlorine. In Ringer physiological solution, the composition of the surface layer changes to a mixture of oxides, chlorides and/or oxychlorides. Two components peaks were detected in the Cl 2p 3/2 peak; however, it was not possible to distinguish the exact nature of the chloride compound formed. The mechanism of nickel release is discussed as a function of the composition of the solution.

  5. The Effect of Varying the Composition of Fingerprint Sweat Deposits on the Corrosion of Brass and Fingerprint Visibility.

    Science.gov (United States)

    Cooper-Dunn, Alice; Jones, Owen; Bond, John W

    2017-09-01

    Corrosion of α-phase brass by sebaceous sweat fingerprint deposits produced identifiable impressions in a majority of samples (n = 40) 4 days after deposition. Combining sebaceous with eccrine sweat yielded a greater percentage of identifiable fingerprint deposits, although this increase was not statistically significant. Production of identifiable fingerprints from eccrine sweat deposits was dependent on the sampling time of year with deposits taken during summer months giving similar percentages of identifiable fingerprints to sebaceous deposits. A statistically significant positive correlation was found between elapsed days after deposition and identifiable eccrine (ρ = 0.787, p sweat deposits was statistically significant compared to winter eccrine deposits (p sweat. © 2017 American Academy of Forensic Sciences.

  6. Sweat osmolarity shows intra-animal regional variation in the horse.

    Science.gov (United States)

    Potts, Samantha; Thatcher, Rhys; Jones, Arwel W; Warren, Lori K; Tenbroeck, Saundra H; Nottage, Florence; McEwan, Neil R

    2015-10-01

    Sweating is important in regulating body temperature but can be a source of loss of both fluids and electrolytes. Although the process has been studied in horses, the variation in sweat osmolarity across the body has not. This work describes an investigation to determine if there is regional variation in the osmolarity of sweat across different anatomical regions of the horse. Ten horses were used in the study and were animals either stabled for riding lessons or had livery on-site. Sweat samples were collected from five regions on each horse following exercise and the osmolarity measurements were made using an Osmomat 030 (Gonotec, Berlin, Germany). Values were analysed by paired t-tests and analysis of variance. Samples from the back and ears had statistically (P sweat collected from the horse's back. The current work demonstrates that these values are probably an underestimation of electrolyte loss, which may have implications for the composition and administration of rehydration compounds. © 2015 ESVD and ACVD.

  7. Jewellery: alloy composition and release of nickel, cobalt and lead assessed with the EU synthetic sweat method.

    Science.gov (United States)

    Hamann, Dathan; Thyssen, Jacob P; Hamann, Carsten R; Hamann, Curtis; Menné, Torkil; Johansen, Jeanne D; Spiewak, Radoslaw; Maibach, Howard; Lundgren, Lennart; Lidén, Carola

    2015-10-01

    Several studies have shown nickel and cobalt release from jewellery by using spot tests, but the metal composition of jewellery is largely unknown. To evaluate the metal composition of a large worldwide sample of mainly inexpensive jewellery items, and investigate the release of nickel, cobalt and lead from a subsample by using EN 1811:1998-required methods. A total of 956 metallic jewellery components were examined with X-ray fluorescence spectroscopy. A subsample of 96 jewellery items purchased in the United States were investigated for nickel, cobalt and lead release by the use of artificial sweat immersion and plasma optical emission spectroscopy. Eighteen elements were detected. The 10 most frequently occurring were, in order of frequency, copper, iron, zinc, nickel, silver, chromium, tin, manganese, lead, and cobalt. Release of nickel was noted from 79 of the 96 US samples (0.01-98 µg/cm(2) /week), release of cobalt from 35 samples (0.02-0.5 µg/cm(2) /week), and release of lead from 37 samples (0.03-2718 µg/cm(2) /week). We present here a comprehensive list of the most frequently encountered metals in jewellery and fashion accessories. Different allergenic and non-allergenic metals are utilized. We also report the frequent release of nickel, cobalt and lead from these objects, despite legislative restrictions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Effect of periglandular ionic composition and transport inhibitors on rhesus monkey eccrine sweat gland function in vitro.

    Science.gov (United States)

    Sato, F; Sato, K

    1987-12-01

    1. The effects of peritubular ions and transport inhibitors were studied on methacholine (MCH)-induced sweat secretion by the isolated, cannulated monkey palm sweat glands in vitro and on the transepithelial and basolateral membrane potential (p.d.). 2. Sweat secretory rate was a curvilinear function of peritubular Na+ and Cl- concentration. Among the anion substitutes only Br- was able to totally substitute for Cl-. Presence of HCO3- or H2PO4- in the bath was not essential. 3. Both bumetanide and furosemide inhibited sweat secretion in a dose-dependent manner with the median effective concentration (EC50) of 3 X 10(-6) and 3 X 10(-5) M, respectively. 4. Bumetanide (10(-4) M) had no significant effect on basolateral membrane p.d. but nearly abolished the transepithelial p.d. 5. Hydrochlorothiazide (HCTZ, 3 X 10(-4) M) inhibited sweat secretion by only 35%. Inhibitors of ion exchangers amiloride (10(-4) M) and DIDS (4,4'-diisothiocyanostilbene-2,2'-disulphonic acid, 10(-4) M) lowered sweat secretion by less than 20%. 6. Removal of peritubular K+ as well as addition of 5 mM-Ba2+ also inhibited sweat rate. 5 mM-Ba2+ abolished the transepithelial p.d. and depolarized the basolateral p.d. by 26 mV, although the effects of Ba2+ on sweating and the transepithelial p.d. were only transient. 7. The data raise a possibility that either the NaCl or Na+-K+-2Cl- co-transport system or both may be involved in MCH-induced sweat secretion, whereas the role of parallel ion exchangers, if any, may be rather minor.

  9. High efficiency solid state dye sensitized solar cells with graphene-polyethylene oxide composite electrolytes.

    Science.gov (United States)

    Akhtar, M Shaheer; Kwon, Soonji; Stadler, Florian J; Yang, O Bong

    2013-06-21

    Novel and highly effective composite electrolytes were prepared by combining the two dimensional graphene (Gra) and polyethylene oxide (PEO) for the solid electrolyte of dye sensitized solar cells (DSSCs). Gra sheets were uniformly coated by the polymer layer through the ester carboxylate bonding between oxygenated species on Gra sheets and PEO. The Gra-PEO composite electrolyte showed the large scale generation of iodide ions in a redox couple. From rheological analysis, the decrease in viscosity after the addition of LiI and I2 in the Gra-PEO electrolyte might be explained by the dipolar interactions being severely disrupted by the ionic interactions of Li(+), I(-), and I3(-) ions. A composite electrolyte with 0.5 wt% Gra presented a higher ionic conductivity (3.32 mS cm(-1)) than those of PEO and other composite electrolytes at room temperature. A high overall conversion efficiency (∼5.23%) with a very high short circuit current (JSC) of 18.32 mA cm(-2), open circuit voltage (VOC) of 0.592 V and fill factor (FF) of 0.48 was achieved in DSSCs fabricated with the 0.5 wt% Gra-PEO composite electrolyte. This enhanced photovoltaic performance might be attributed to the large scale formation of iodide ions in the redox electrolyte and the relatively high ionic conductivity.

  10. Zinc-based electrolyte compositions, and related electrochemical processes and articles

    Energy Technology Data Exchange (ETDEWEB)

    Kniajanski, Sergei; Soloveichik, Grigorii Lev

    2018-02-20

    An aqueous electrolyte composition is described, including a zinc salt based on zinc acetate or zinc glocolate. The saturation concentration of zinc in the electrolyte composition is in the range of about 2.5M to about 3.5M. The composition also contains at least one salt of a monovalent cation. The molar ratio of zinc to the monovalent cation is about 1:2. An aqueous zinc electroplating bath, containing the aqueous electrolyte composition, is also disclosed, along with a method for the electrochemical deposition of zinc onto a substrate surface, using the electroplating bath. Related flow batteries are also described, including a catholyte, as well as an anolyte based on the aqueous electrolyte composition, with a membrane between the catholyte and the anolyte.

  11. Working Up a Good Sweat – The Challenges of Standardising Sweat Collection for Metabolomics Analysis

    Science.gov (United States)

    Hussain, Joy N; Mantri, Nitin; Cohen, Marc M

    2017-01-01

    Introduction Human sweat is a complex biofluid of interest to diverse scientific fields. Metabolomics analysis of sweat promises to improve screening, diagnosis and self-monitoring of numerous conditions through new applications and greater personalisation of medical interventions. Before these applications can be fully developed, existing methods for the collection, handling, processing and storage of human sweat need to be revised. This review presents a cross-disciplinary overview of the origins, composition, physical characteristics and functional roles of human sweat, and explores the factors involved in standardising sweat collection for metabolomics analysis. Methods A literature review of human sweat analysis over the past 10 years (2006–2016) was performed to identify studies with metabolomics or similarly applicable ‘omics’ analysis. These studies were reviewed with attention to sweat induction and sampling techniques, timing of sweat collection, sweat storage conditions, laboratory derivation, processing and analytical platforms. Results Comparative analysis of 20 studies revealed numerous factors that can significantly impact the validity, reliability and reproducibility of sweat analysis including: anatomical site of sweat sampling, skin integrity and preparation; temperature and humidity at the sweat collection sites; timing and nature of sweat collection; metabolic quenching; transport and storage; qualitative and quantitative measurements of the skin microbiota at sweat collection sites; and individual variables such as diet, emotional state, metabolic conditions, pharmaceutical, recreational drug and supplement use. Conclusion Further development of standard operating protocols for human sweat collection can open the way for sweat metabolomics to significantly add to our understanding of human physiology in health and disease. PMID:28798503

  12. Sweat sensor for sports physiological monitoring

    OpenAIRE

    Benito-Lopez, Fernando; Coyle, Shirley; Diamond, Dermot

    2011-01-01

    The fabrication and the performance of a novel, wearable, robust, flexible and disposable micro-fluidic device which incorporates miniature optical components as a detection system, for wireless monitoring in real time mode of sweat pH during an exercise session is presented. This micro-fluidic platform is completely non-invasive, providing a continuous flow of fresh sweat for continuous real time analysis, ensuring immediate feedback regarding sweat composition to an athlete and/or coach.

  13. Doped ceria-chloride composite electrolyte for intermediate temperature ceramic membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Q.X.; Zhang, W.; Peng, R.R.; Peng, D.K.; Meng, G.Y.; Zhu, B. [Department of Materials Science and Engineering, University of Science and Technology of China, 230026 Hefei (China)

    2002-03-01

    A kind of oxide-salt composite electrolyte, gadolinium-doped ceria (GDC)-LiCl-SrCl{sub 2}, prepared with hot-press technique, shows superior ionic conductivity, which is 2-10 times higher than that of GDC itself at the temperature range of 400-600C. More interestingly, not like the GDC electrolyte, which has some extent of electronic conduction under reducing atmosphere, the composite electrolyte is almost a pure ionic conductor, evidenced by the fuel cell's (FC) open circuit voltage (OCV) close to the theoretical one. The fuel cells based on this composite electrolyte show excellent power density output even at temperature as low as 500C (240 mW cm{sup -2} ) in spite of the relatively thick electrolyte (0.4 mm). Such high performance, in combination with its low cost in both raw materials and fabrication process, make this kind of composite electrolyte a good candidate electrolyte material for future ultra-low-cost intermediate temperature ceramic membrane fuel cells (IT-CMFCs)

  14. Electrolyte concentration in sweat, urine, blood and feces of horses undergone to different temperatures Concentração de eletrólitos em eqüinos submetidos a diferentes temperaturas

    Directory of Open Access Journals (Sweden)

    Alexandre Augusto de Oliveira Gobesso

    2009-03-01

    Full Text Available This study aimed to quantify sweat, urine and fecal losses of sodium, potassium and chloride and its variations in blood concentration of equine ones in rest subjected to the climatic predominant conditions in Brazil. Eight 13-mo-old Arabian-crossbred filies were used, four accommodated ones in cages for metabolic individual studies in open shed, covered with roof and exposed to a maximum temperature of 28.33 ± 0.81°C, and four in climatic chamber with environment heated to the maximum temperature of 35.33 ± 0.81°C. Electrolyte concentration in sweat, urine, blood and feces were measured. After 25 days of adaptation to cages, six days for sampling were performed. Individual and daily feed and water intake, sweating rate, respiratory rate, rectal temperature, urine and fecal excretion were recorded. Significantly higher urinary and sweat electrolyte loss in those animals exposed to hotter conditions indicate the need of an increase in mineral supplementation in equine nutrition in Brazil.Objetivou-se com este projeto quantificar as perdas sudativas, urinárias e fecais e a variação da concentração sangüínea de cloreto, sódio e potássio de eqüinos em repouso submetidos às condições climáticas predominantes no Brasil. Foram utilizadas oito fêmeas mestiças da raça Árabe, de 13 meses de idade em média, quatro alojadas em gaiolas para estudos metabólicos individuais em galpão aberto, com cobertura em telha cerâmica, em ambiente natural, e temperatura média máxima de 28,33 ± 0,81°C, e quatro em câmara climática com ambiente aquecido à temperatura máxima de 35,33 ± 0,81°C. Foram analisadas as concentrações dos eletrólitos no suor, no sangue, nas fezes e na urina. Após 25 dias de adaptação às gaiolas, procedeu-se à coleta das amostras durante seis dias. Foram registrados o consumo individual diário de volumoso, concentrado e água, a taxa de sudação, a freqüência respiratória, a temperatura retal e a excre

  15. Hydration, sweat and thermoregulatory responses to professional football training in the heat.

    Science.gov (United States)

    Duffield, Rob; McCall, Allan; Coutts, Aaron James; Peiffer, Jeremiah John

    2012-01-01

    AbstThis study examined the relationship between intensity of training and changes in hydration status, core temperature, sweat rate and composition and fluid balance in professional football players training in the heat. Thirteen professional football players completed three training sessions; "higher-intensity" (140 min; HI140), "lower-intensity" (120 min; LI120) and "game-simulation" (100 min; GS100). Movement demands were measured by Global Positioning System, sweat rate and concentration were determined from dermal patches and body mass change. Despite similar environmental conditions (26.9 ± 0.1 °C and 65.0 ± 7.0% relative humidity [Rh]), higher relative speeds (m · min(-1)) and increased perceptions of effort and thermal strain were observed in HI140 and GS100 compared with LI120 (P sweat rate (L · h(-1)) and electrolyte losses (g) were observed in HI140 and GS100 compared with LI120. Rate of rise in core temperature was correlated with mean speed (r = 0.85), session rating of perceived exertion (sRPE) (r = 0.61), loss of potassium (K+) (r = 0.51) sweat rate (r = 0.49), and total sweat loss (r = 0.53), with mean speed the strongest predictor. Sodium (Na+) (r = 0.39) and K+ (r = 0.50) losses were associated with total distance covered. In hot conditions, individualised rehydration practices should be adopted following football training to account for differences in sweat rate and electrolyte losses in response to intensity and overall activity within a session.

  16. Lithium sulfide compositions for battery electrolyte and battery electrode coatings

    Science.gov (United States)

    Liang, Chengdu; Liu, Zengcai; Fu, Wunjun; Lin, Zhan; Dudney, Nancy J; Howe, Jane Y; Rondinone, Adam J

    2013-12-03

    Methods of forming lithium-containing electrolytes are provided using wet chemical synthesis. In some examples, the lithium containing electroytes are composed of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7. The solid electrolyte may be a core shell material. In one embodiment, the core shell material includes a core of lithium sulfide (Li.sub.2S), a first shell of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7, and a second shell including one or .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7 and carbon. The lithium containing electrolytes may be incorporated into wet cell batteries or solid state batteries.

  17. Carbon nanotubes-polyethylene oxide composite electrolyte for solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shaheer Akhtar, M. [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, Dukjin dong, Dukjin Gu, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Department of Semiconductor Science and Technology, SPRC, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Park, Jung-Geun; Lee, Hyun-Cheol [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, Dukjin dong, Dukjin Gu, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Lee, S.-K. [Department of Semiconductor Science and Technology, SPRC, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Yang, O-Bong, E-mail: obyang@chonbuk.ac.k [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, Dukjin dong, Dukjin Gu, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

    2010-02-28

    Novel carbon nanotubes (CNTs)-polyethylene oxide (PEO) composite electrolyte for dye-sensitized solar cell (DSSC) was prepared and characterized for the first time. The strong bonding and interaction between CNTs and PEO in CNTs-PEO composites was observed by the characterization of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Raman spectra. The introduction of CNTs into PEO matrix significantly improved the electrolyte properties of DSSC such as roughness, amorphicity and ionic conductivity. The solid-state DSSC fabricated with the optimum composite electrolyte (added 1% CNTs in PEO matrix, 1%CNT-PEO) achieved maximum conversion efficiency of 3.5%, an open circuit voltage (V{sub OC}) of 0.589 V, short circuit current density (J{sub SC}) of 10.64 mA/cm{sup 2} and fill factor (FF) of 56%. The highest IPCE in the DSSC fabricated with 1%CNT-PEO electrolyte is ascribed to the improved ionic conductivity of composite electrolytes and enhanced interfacial contact between electrode and electrolyte.

  18. Jet Electrochemical Machining of Particle Reinforced Aluminum Matrix Composites with Different Neutral Electrolytes

    Science.gov (United States)

    Hackert-Oschätzchen, M.; Lehnert, N.; Martin, A.; Schubert, A.

    2016-03-01

    Conventional mechanical machining of particle reinforced aluminum matrix composites (AMCs) is challenging because the hard ceramic particles in the soft aluminum matrix lead to an increased tool wear. Furthermore, the mechanical and thermal impact during conventional machining affects the microstructure of the AMCs. Electrochemical machining (ECM) is an alternative method to machine AMCs. Based on anodic dissolution, ECM has a slight influence on the work piece material structure and is independent of material strength and hardness. So the microstructure of the work piece remains unaffected. One method of ECM is electrochemical machining with continuous electrolytic free jet (Jet-ECM). Hereby the electrochemical removal is localized by the geometry of the electrolyte jet. By moving the electrolyte jet micro-structures and microgeometries can be generated quickly and flexibly in metallic parts [1]. Another advantage of Jet-ECM is the low consumption of electrolyte which allows an easy and inexpensive change of electrolyte for investigations with different types of electrolyte. In this study AMCs reinforced with different amounts of SiC-particles are machined with two pH-neutral electrolytes using Jet-ECM. The results provide information about the suitability of the selected electrolytes for the machining of AMCs. In addition, the influence of the particle content on the electrochemical removal result will be evaluated.

  19. Proton-conductive nano zeolite-PVA composite film as a new water-absorbing electrolyte for water electrolysis

    Directory of Open Access Journals (Sweden)

    M. Nishihara

    2018-03-01

    Full Text Available In this study, organic-inorganic composite electrolyte membranes are developed for a novel water-absorbing porous electrolyte water electrolysis cell. As the materials of the composite electrolyte membrane, 80 wt% of a proton-conducting nano zeolite (H-MFI as an electrolyte and 20 wt% of poly(vinyl alcohol (PVA as a cross-linkable matrix are used. The nano zeolite is prepared by a milling process. The nano zeolite-PVA composite membrane precursors are prepared by spraying onto a substrate, followed by cross-linking. The resulting nano zeolite-cross-linked PVA composite films are then evaluated for their properties such as proton conductivity as electrolyte membranes for the water-absorbing porous electrolyte water electrolysis cell. It is confirmed that conventional materials such as zeolites and PVA can be used for the water electrolysis as an electrolyte.

  20. Enhancing ionic conductivity in composite polymer electrolytes with well-aligned ceramic nanowires

    Science.gov (United States)

    Liu, Wei; Lee, Seok Woo; Lin, Dingchang; Shi, Feifei; Wang, Shuang; Sendek, Austin D.; Cui, Yi

    2017-04-01

    In contrast to conventional organic liquid electrolytes that have leakage, flammability and chemical stability issues, solid electrolytes are widely considered as a promising candidate for the development of next-generation safe lithium-ion batteries. In solid polymer electrolytes that contain polymers and lithium salts, inorganic nanoparticles are often used as fillers to improve electrochemical performance, structure stability, and mechanical strength. However, such composite polymer electrolytes generally have low ionic conductivity. Here we report that a composite polymer electrolyte with well-aligned inorganic Li+-conductive nanowires exhibits an ionic conductivity of 6.05 × 10-5 S cm-1 at 30 ∘C, which is one order of magnitude higher than previous polymer electrolytes with randomly aligned nanowires. The large conductivity enhancement is ascribed to a fast ion-conducting pathway without crossing junctions on the surfaces of the aligned nanowires. Moreover, the long-term structural stability of the polymer electrolyte is also improved by the use of nanowires.

  1. Corrosion behavior of Mg/graphene composite in aqueous electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Selvam, M. [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India); Saminathan, K., E-mail: ksaminath@gmail.com [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India); Siva, P. [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India); Saha, P. [Department of Ceramic Engineering, National Institute of Technology, Rourkela, India-769008 (India); Rajendran, V. [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India)

    2016-04-01

    In the present work, the electrochemical corrosion behavior of magnesium (Mg) and thin layer graphene coated Mg (Mg/graphene) are studied in different salt electrolyte such as NaCl, KCl and Na{sub 2}SO{sub 4}. The phase structure, crystallinity, and surface morphology of the samples are investigated using X-ray diffraction (XRD) analysis, scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDAX), and Raman spectroscopy techniques. The electrochemical corrosion behavior of the Mg and graphene coated Mg are also investigated using Electrochemical Impedance Spectroscopy (EIS) analysis. The tafel plot reveals that the corrosion of Mg drastically drops when coated with thin layer graphene (Mg/graphene) compared to Mg in KCl electrolyte. Moreover, the EIS confirms that Mg/graphene sample shows improve corrosion resistance and lower corrosion rate in KCl solution compare to all other electrolytes studied in the present system. - Highlights: • The corrosion behavior of magnesium alloy (AZ91) was investigated in three different electrolyte solution. • To study the anti-corrosion behavior of graphene coated with magnesium alloy. • To improve the corrosion resistance for magnesium alloy. • Nyquist plots confirms that MgG shows better corrosion resistance and lower corrosion rate in KCl solution.

  2. Effect of multiparity on electrolyte composition and blood pressure ...

    African Journals Online (AJOL)

    Pregnancy affects the physiology of the pregnant woman particularly the endocrine, cardiovascular and the renal systems. This work was therefore set to ascertain the state of electrolytes in pregnancy and how it affects blood pressure using multiparity as a factor. One hundred and twenty (120) women were used in this ...

  3. Electrolyte Composition for Distinguishing Corrosion Mechanisms in Steel Alloy Screening

    Directory of Open Access Journals (Sweden)

    Ingmar Bösing

    2017-01-01

    Full Text Available The formation and breakdown of passive layers due to pitting corrosion are a major cause of failure of metal structures. The investigation of passivation and pitting corrosion requires two different electrochemical measurements and is therefore a time consuming process. To reduce time in material characterization and to study the interactions of both mechanisms, here, a combined experiment addressing both phenomena is introduced. In the presented electrolyte the different corrosion mechanisms are distinguished and investigated by cyclic voltammograms and polarization scans. The measurements show a passive area, metastable pit growth, and pitting corrosion as well as repassivation. The pitting corrosion is separated from additional dissolution processes and the standard deviation of the corrosion potential is smaller than in other electrolytes. Both passivation and pitting corrosion can be observed in one measurement without additional corrosion attacks. The deviation between different measurements of the same steel is small; this is helpful for the screening of similar materials.

  4. Luminescent Polymer Electrolyte Composites Using Silica Coated-Y2O3:Eu as Fillers

    Directory of Open Access Journals (Sweden)

    Mikrajuddin Abdullah

    2003-05-01

    Full Text Available Luminescent polymer electrolyte composites composed of silica coated Y2O3:Eu in polyethylene glycol (PEG matrix has been produced by initially synthesizing silica coated Y2O3:Eu and mixing with polyethylene glycol in a lithium salt solution. High luminescence intensity at round 600 nm contributed by electron transitions in Eu3+ (5D0 -> 7F0, 5D0 -> 7F1, and 5D0 -> 7F3 transitions were observed. The measured electrical conductivity was comparable to that reported for polymer electrolyte composites prepared using passive fillers (non luminescent. This approach is therefore promising for production of high intensity luminescent polymer electrolyte composites for use in development of hybrid battery/display.

  5. The conductivity and stability of polymer composite solid electrolyte upon addition of graphene

    Science.gov (United States)

    Hamid, Farzana Abd.; Salleh, Fauzani Md.; Mohamed, Nor Sabirin

    2017-12-01

    The effect of graphene composition on the conductivity and stability of polymer composite solid electrolyte was studied. These polymer composite solid electrolytes were synthesized by sol gel method and prepared via the solution-casting technique. The compositions of graphene were varied between 10 wt% to 70 wt%. The changes in the functional group of polymer composite after the addition of graphene were characterized by Fourier Transform InfraRed spectroscopy. Electrochemical impedance spectroscopy was conducted at ambient temperature in the frequency range of 10 Hz to 1 MHz to study the conductivity of the polymer composite. The highest conductivity was obtained at 60 wt% graphene with the value of 2.85×10-4 Scm-1. Sample without the addition of graphene showed the lowest conductivity value of 1.77×10-7 Scm-1 and acts as an insulator. The high conductivity at 60 wt% graphene loading is related to dehydration of cellulose. This is supported by the FTIR spectrum where the absorption peaks of C-O stretching vibrations of polymer composite is weakened and the hydroxyl group is slightly shifted compared to the FTIR spectrum without the addition of graphene. Linear sweep voltammetry results demonstrated that the polymer composite solid electrolyte exhibited electrochemical stability up to 3.2 V.

  6. Solid polymer electrolyte composite membrane comprising a porous support and a solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide

    Science.gov (United States)

    Liu, Han; Mittelsteadt, Cortney K; Norman, Timothy J; Griffith, Arthur E; LaConti, Anthony B

    2015-02-24

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a thin, rigid, dimensionally-stable, non-electrically-conducting support, the support having a plurality of cylindrical, straight-through pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores are unevenly distributed, with some or no pores located along the periphery and more pores located centrally. The pores are completely filled with a solid polymer electrolyte, the solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide. The solid polymer electrolyte may also be deposited over the top and/or bottom surfaces of the support.

  7. Polybenzimidazole and sulfonated polyhedral oligosilsesquioxane composite membranes for high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Aili, David; Allward, Todd; Alfaro, Silvia Martinez

    2014-01-01

    Composite membranes based on poly(2,2′(m-phenylene)-5,5́bibenzimidazole) (PBI) and sulfonated polyhedral oligosilsesquioxane (S-POSS) with S-POSS contents of 5 and 10wt.% were prepared by solution casting as base materials for high temperature polymer electrolyte membrane fuel cells. With membranes...

  8. Random-network simulation of an ultracapacitor based on metal-solid-electrolyte composite

    Science.gov (United States)

    Abel, J.; Kornyshev, A. A.

    1996-09-01

    A random-network model of a dense (pore-free) metal-solid-electrolyte composite is developed. Real and imaginary parts of admittance are simulated as a function of frequency and composition by means of the transfer matrix algorithm on a cubic lattice. For a composite without a solid-electrolyte membrane in the middle (insulating with respect to electronic current) the results predict the capacity maximum at the percolation threshold in three dimensions and two maxima in two dimensions as a function of composition; they are compared with the predictions of the effective medium theory. For a composite with an insulating membrane in the middle, typical for ultracapacitors, the maximum of capacitance in three dimensions is at equal portion of metal and solid-electrolyte particles. In contrast to metal dielectric mixtures there are no giant enhancement effects in static capacitance as a function of composition: the upper estimates of the enhancement factor are proportional to the ratio of the size of the sample to the size of the grains.

  9. The choice of the conditions to receive the electrolytic zinc powders for metal-rich compositions

    Directory of Open Access Journals (Sweden)

    A. V. Patrushev

    2015-03-01

    Full Text Available In the work a method of obtaining highly dispersed zinc powders by electrolysis and comparison of the properties of zinc-rich compositions prepared using as a pigment zinc powders obtained by different methods is provided. Conducted measurements have shown that the electrical conductivity of zinc-rich coatings comprising electrolytic zinc powder does not inferior to the conductivity of the film with PZHD-0 powder obtained by the  evaporation-condensation method, despite the significant difference in the amount of zinc pigment. On the basis of the received data one can conclude that the use of electrolytic zinc powder as a pigment will significantly save zinc.

  10. Electrolytes and thermoregulation

    Science.gov (United States)

    Nielsen, B.; Greenleaf, J. E.

    1977-01-01

    The influence of ions on temperature is studied for cases where the changes in ionic concentrations are induced by direct infusion or injection of electrolyte solutions into the cerebral ventricles or into specific areas of brain tissue; intravenous infusion or injection; eating food or drinking solutions of different ionic composition; and heat or exercise dehydration. It is shown that introduction of Na(+) and Ca(++) into the cerebral ventricles or into the venous system affects temperature regulation. It appears that the specific action of these ions is different from their osmotic effects. It is unlikely that their action is localized to the thermoregulatory centers in the brain. The infusion experiments demonstrate that the changes in sodium balance occurring during exercise and heat stress are large enough to affect sweat gland function and vasomotor activity.

  11. Composite electrolyte with proton conductivity for low-temperature solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Raza, Rizwan, E-mail: razahussaini786@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Energy Technology, Royal Institute of Technology, KTH, Stockholm 10044 (Sweden); Ahmed, Akhlaq; Akram, Nadeem; Saleem, Muhammad; Niaz Akhtar, Majid; Ajmal Khan, M.; Abbas, Ghazanfar; Alvi, Farah; Yasir Rafique, M. [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Sherazi, Tauqir A. [Department of Chemistry, COMSATS Institute of Information Technology, Abbotabad 22060 (Pakistan); Shakir, Imran [Sustainable Energy Technologies (SET) center, College of Engineering, King Saud University, PO-BOX 800, Riyadh 11421 (Saudi Arabia); Mohsin, Munazza [Department of Physics, Lahore College for Women University, Lahore, 54000 (Pakistan); Javed, Muhammad Sufyan [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Applied Physics, Chongqing University, Chongqing 400044 (China); Zhu, Bin, E-mail: binzhu@kth.se, E-mail: zhubin@hubu.edu.cn [Department of Energy Technology, Royal Institute of Technology, KTH, Stockholm 10044 (Sweden); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Physics and Electronic Science/Faculty of Computer and Information, Hubei University, Wuhan, Hubei 430062 (China)

    2015-11-02

    In the present work, cost-effective nanocomposite electrolyte (Ba-SDC) oxide is developed for efficient low-temperature solid oxide fuel cells (LTSOFCs). Analysis has shown that dual phase conduction of O{sup −2} (oxygen ions) and H{sup +} (protons) plays a significant role in the development of advanced LTSOFCs. Comparatively high proton ion conductivity (0.19 s/cm) for LTSOFCs was achieved at low temperature (460 °C). In this article, the ionic conduction behaviour of LTSOFCs is explained by carrying out electrochemical impedance spectroscopy measurements. Further, the phase and structure analysis are investigated by X-ray diffraction and scanning electron microscopy techniques. Finally, we achieved an ionic transport number of the composite electrolyte for LTSOFCs as high as 0.95 and energy and power density of 90% and 550 mW/cm{sup 2}, respectively, after sintering the composite electrolyte at 800 °C for 4 h, which is promising. Our current effort toward the development of an efficient, green, low-temperature solid oxide fuel cell with the incorporation of high proton conductivity composite electrolyte may open frontiers in the fields of energy and fuel cell technology.

  12. Composite materials for polymer electrolyte membrane microbial fuel cells.

    Science.gov (United States)

    Antolini, Ermete

    2015-07-15

    Recently, the feasibility of using composite metal-carbon, metal-polymer, polymer-carbon, polymer-polymer and carbon-carbon materials in microbial fuel cells (MFCs) has been investigated. These materials have been tested as MFC anode catalyst (microorganism) supports, cathode catalysts and membranes. These hybrid materials, possessing the properties of each component, or even with a synergistic effect, would present improved characteristics with respect to the bare components. In this paper we present an overview of the use of these composite materials in microbial fuel cells. The characteristics of the composite materials as well as their effect on MFC performance were compared with those of the individual component and/or the conventionally used materials. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. An anion-immobilized composite electrolyte for dendrite-free lithium metal anodes.

    Science.gov (United States)

    Zhao, Chen-Zi; Zhang, Xue-Qiang; Cheng, Xin-Bing; Zhang, Rui; Xu, Rui; Chen, Peng-Yu; Peng, Hong-Jie; Huang, Jia-Qi; Zhang, Qiang

    2017-10-17

    Lithium metal is strongly regarded as a promising electrode material in next-generation rechargeable batteries due to its extremely high theoretical specific capacity and lowest reduction potential. However, the safety issue and short lifespan induced by uncontrolled dendrite growth have hindered the practical applications of lithium metal anodes. Hence, we propose a flexible anion-immobilized ceramic-polymer composite electrolyte to inhibit lithium dendrites and construct safe batteries. Anions in the composite electrolyte are tethered by a polymer matrix and ceramic fillers, inducing a uniform distribution of space charges and lithium ions that contributes to a dendrite-free lithium deposition. The dissociation of anions and lithium ions also helps to reduce the polymer crystallinity, rendering stable and fast transportation of lithium ions. Ceramic fillers in the electrolyte extend the electrochemically stable window to as wide as 5.5 V and provide a barrier to short circuiting for realizing safe batteries at elevated temperature. The anion-immobilized electrolyte can be applied in all-solid-state batteries and exhibits a small polarization of 15 mV. Cooperated with LiFePO 4 and LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathodes, the all-solid-state lithium metal batteries render excellent specific capacities of above 150 mAh⋅g -1 and well withstand mechanical bending. These results reveal a promising opportunity for safe and flexible next-generation lithium metal batteries.

  14. Sex differences in amino acids lost via sweating could lead to differential susceptibilities to disturbances in nitrogen balance and collagen turnover

    OpenAIRE

    Dunstan, R. H.; Sparkes, D. L.; Dascombe, B. J.; Stevens, C. J.; Murphy, G. R.; Macdonald, M. M.; Gottfries, J.; Gottfries, C.-G.; Roberts, T. K.

    2017-01-01

    Fluid collected during sweating is enriched with amino acids derived from the skin?s natural moisturising factors and has been termed ?faux? sweat. Little is known about sex differences in sweat amino acid composition or whether faux sweat amino acid losses affect nitrogen balance. Faux sweat collected by healthy adults (n?=?47) after exercise, and at rest by chronic fatigue patients, was analysed for amino acid composition. Healthy females had higher total amino acid concentrations in sweat ...

  15. Magnetoelectric effect of polymer electrolyte composites with Terfenol-D and lead zirconate titanate inclusions

    Science.gov (United States)

    Chau, K. H.; Wong, Y. W.; Shin, F. G.

    2009-05-01

    The magnetoelectric effects of three-phase composites in 0-0-3 connectivity were investigated. The composites consist of particulate Terfenol-D and lead zirconate titanate blended in different polymer matrices. The magnetoelectric coefficient αq, which is the charge density change in response to a change in the applied magnetic field, of the samples was measured under short circuit condition. The results show that the αq of the samples with an electrolytic polymer matrix is larger than that of the samples with an insulating matrix, while samples with an ion-doped electrolytic polymer matrix exhibit the largest αq. These results conform with the expectation that higher matrix conductivity has an effect of enhancing the magnetoelectric signals.

  16. Eccrine sweat gland development and sweat secretion.

    Science.gov (United States)

    Cui, Chang-Yi; Schlessinger, David

    2015-09-01

    Eccrine sweat glands help to maintain homoeostasis, primarily by stabilizing body temperature. Derived from embryonic ectoderm, millions of eccrine glands are distributed across human skin and secrete litres of sweat per day. Their easy accessibility has facilitated the start of analyses of their development and function. Mouse genetic models find sweat gland development regulated sequentially by Wnt, Eda and Shh pathways, although precise subpathways and additional regulators require further elucidation. Mature glands have two secretory cell types, clear and dark cells, whose comparative development and functional interactions remain largely unknown. Clear cells have long been known as the major secretory cells, but recent studies suggest that dark cells are also indispensable for sweat secretion. Dark cell-specific Foxa1 expression was shown to regulate a Ca(2+) -dependent Best2 anion channel that is the candidate driver for the required ion currents. Overall, it was shown that cholinergic impulses trigger sweat secretion in mature glands through second messengers - for example InsP3 and Ca(2+) - and downstream ion channels/transporters in the framework of a Na(+) -K(+) -Cl(-) cotransporter model. Notably, the microenvironment surrounding secretory cells, including acid-base balance, was implicated to be important for proper sweat secretion, which requires further clarification. Furthermore, multiple ion channels have been shown to be expressed in clear and dark cells, but the degree to which various ion channels function redundantly or indispensably also remains to be determined. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  17. Testing in artificial sweat - Is less more? Comparison of metal release in two different artificial sweat solutions.

    Science.gov (United States)

    Midander, Klara; Julander, Anneli; Kettelarij, Jolinde; Lidén, Carola

    2016-11-01

    Metal release from materials immersed in artificial sweat can function as a measure of potential skin exposure. Several artificial sweat models exist that, to various degree, mimic realistic conditions. Study objective was to evaluate metal release from previously examined and well characterized materials in two different artificial sweat solutions; a comprehensive sweat model intended for use within research, based on the composition of human sweat; and the artificial sweat, EN1811, intended for testing compliance with the nickel restriction in REACH. The aim was to better understand whether there are advantages using either of the sweat solutions in bio-elution testing of materials. Metal release in two different artificial sweat solutions was compared for discs of a white gold alloy and two hard metals, and a rock drilling insert of tungsten carbide at 1 h, 24 h, 1 week and 1 month. The released amount of metal was analysed by means of inductively coupled plasma mass spectrometry. Similar levels of released metals were measured from test materials in the two different artificial sweat solutions. For purposes in relation to legislations, it was concluded that a metal release test using a simple artificial sweat composition may provide results that sufficiently indicate the degree of metal release at skin contact. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Effects of stimulation technique, anatomical region and time on human sweat lipid mediator profiles.

    Science.gov (United States)

    Few studies compare sampling protocol effect on sweat composition. Here we evaluate the impact of sweat stimulation mode and site of collection on lipid mediator composition. Sweat from healthy males (n = 7) was collected weekly for three weeks from the volar forearm following either pilocarpine ion...

  19. Structural, Thermal, and Electrical Properties of PVA-Sodium Salicylate Solid Composite Polymer Electrolyte

    Directory of Open Access Journals (Sweden)

    Noorhanim Ahad

    2012-01-01

    Full Text Available Structural, thermal, and electrical properties of solid composite polymer electrolytes based on poly (vinyl alcohol complexed with sodium salicylate were studied. The polymer electrolytes at different weight percent ratios were prepared by solution casting technique. The changes in the structures of the electrolytes were characterized by XRD, which revealed the amorphous domains of the polymer which increased with increase of sodium salicylate concentration. The complexion of the polymer electrolytes were confirmed by FTIR studies. Thermal gravimetric analysis (TGA was used to study the thermal stability of the polymer below 523 K. The decomposition decreases with increasing sodium salicylate concentration. The conductivity and dielectric properties were measured using an impedance analyzer in frequency range of 20 Hz to 1 MHz and narrow temperature range of 303 to 343 K. The conductivity increased with increase of sodium salicylate concentration and temperature. The dielectric constant and dielectric loss increased with the increase in temperature and decreased with the increase in sodium salicylate concentration.

  20. 'My sweat my health': Real time sweat analysis using wearable micro-fluidic devices

    OpenAIRE

    Curto, Vincenzo F.; Angelov, Nikolay; Coyle, Shirley; Byrne, Robert; Hughes, Sarah; Moyna, Niall; Diamond, Dermot; Benito-Lopez, Fernando

    2011-01-01

    In this work a robust, non-invasive and wearable micro-fluidic system was developed and employed to analyse pH of sweat in real time during exercise. The device is incorporated in an optical detection platform designed to provide real-time information on sweat composition. The device has been tested by monitoring the pH of sweat during 55 minutes of cycling activity. During these trials, the data obtained by the micro-fluidic system was compared to pH measurements obtained in parallel studies...

  1. Immunohistochemical sweat gland profiles.

    Science.gov (United States)

    Noël, Fanchon; Piérard, Gérald E; Delvenne, Philippe; Quatresooz, Pascale; Humbert, Philippe; Piérard-Franchimont, Claudine

    2013-09-01

    Human sweat glands are heterogeneous in their structures and functions. Accordingly, eccrine, apocrine, and apoeccrine glands are distinguished. Some immunohistochemical markers are expected to distinguish the sweat gland types in their secretory and excretory parts. This study used two sets of antibodies. The first panel was composed of antibodies directed to well-defined sweat gland structures. The molecular targets included the low-molecular-weight cytokeratins CAM 5.2, the S100-B protein, the epithelial membrane antigen (EMA), the carcinoembryonic antigen (CEA), and the lectin Ulex europaeus agglutinin-1 (UEA-1). A second exploratory panel of antibodies targeted syndecan-1 (CD138), NKI-C3 (CD63), and CD68. They were used to disclose some undescribed antigen expressions in human sweat glands. The first set of antibodies confirmed previous findings. The immunoreactivities of the three sweat gland types were similar in the excretory ducts. By contrast, they were distinguished in the deeper coiled secretory portions of the glands. Clues supporting their distinction and probably their functional activity were obtained by immunohistochemistry using the S100-B protein, CEA and CD63 antibodies. The immunoreactivity to the S100-B protein, CEA and CD63 possibly help identifying apoeccrine sweat glands or a peculiar functional activity of eccrine sweat glands. © 2013 Wiley Periodicals, Inc.

  2. Composite polymer electrolyte based on PEO/Pvdf-HFP with MWCNT for lithium battery applications

    Energy Technology Data Exchange (ETDEWEB)

    Pradeepa, P.; Edwinraj, S.; Sowmya, G.; Kalaiselvimary, J.; Selvakumar, K.; Prabhu, M. Ramesh, E-mail: email-mkram83@gmail.com [Department of Physics, Alagappa University, Karaikudi – 630 004 (India)

    2016-05-06

    In the present study PEO and PVdF-HFP blend based composite polymer electrolytes (CPEs) has been prepared by using Multi Walled Carbon Nanotube (MWCNT), in order to examine the filler addition effect on the electrochemical properties. The complexed nanocomposite polymer electrolytes were obtained in the form of dimensionally stable and free standing films by using solution casting technique. The electrochemical properties of CPEs were measured by the AC impedance method. From the ionic conductivity results, the CPE containing MWCNT 2wt% showed the highest ionic conductivity with an excellent thermal stability at room temperature. The dielectric loss curve s for the sample 6.25wt% PEO: 18.75 wt% PVdF-HFP: 2wt% MWCNT reveal the low frequency β relaxation peak pronounced at high temperature, and it may caused by side group dipoles.

  3. Producing Gas-selective Electrochemical Microsensors by Tuning Solid Electrolyte Composition

    Directory of Open Access Journals (Sweden)

    1Erika SHOEMAKER ELLIS

    2008-10-01

    Full Text Available Abstract: Monolithic gas sensors, developed at Argonne National Laboratory, employed cyclic voltammetry measurement techniques, YSZ solid electrolyte electrochemical cells and K-nearest neighbor (neural chemometrics techniques to sense multiple components in a gas mixture. These voltammetry-based devices detected most hydrocarbons, displayed no saturation effects and were functional from < 1 ppm to 100 % oxygen concentrations, but were not sensitive to carbon dioxide due to the lack of reactivity within the Pt electrodes. Investigations revealed that specific CO2 sensitivity could be introduced by adding tungsten stabilized bismuth oxide (WBO to the solid electrolyte composition while maintaining the same basic sensor geometry and electrode configuration. The YSZ/WBO sensors are functional in a range of CO2 concentrations from low ppm to 100 %.

  4. Sixty-five years since the New York heat wave: advances in sweat testing for cystic fibrosis.

    Science.gov (United States)

    Collie, Jake T B; Massie, R John; Jones, Oliver A H; LeGrys, Vicky A; Greaves, Ronda F

    2014-02-01

    The sweat test remains important as a diagnostic test for cystic fibrosis (CF) and has contributed greatly to our understanding of CF as a disease of epithelial electrolyte transport. The standardization of the sweat test, by Gibson and Cooke [Gibson and Cooke (1959) Pediatrics 1959;23:5], followed observations of excessive dehydration amongst patients with CF and confirmed the utility as a diagnostic test. Quantitative pilocarpine iontophoresis remains the gold standard for sweat induction, but there are a number of collection and analytical methods. The pathophysiology of electrolyte transport in sweat was described by Quinton [Quinton (1983) Nature 1983;301:421-422], and this complemented the developments in genetics that discovered the cystic fibrosis transmembrane conductance regulator (CFTR), an epithelial-based electrolyte transport protein. Knowledge of CF has since increased rapidly and further developments in sweat testing include: new collection methods, further standardization of the technique with international recommendations and age related reference intervals. More recently, sweat chloride values have been used as proof of effect for the new drugs that activate CFTR. However, there remain issues with adherence to sweat test guidelines in many countries and there are gaps in our knowledge, including reference intervals for some age groups and stability of sweat samples in transport. Furthermore, modern methods of elemental quantification need to be explored as alternatives to the original analytical methods for sweat electrolyte measurement. The purpose of this review is therefore to describe the development of the sweat test and consider future directions. © 2013 Wiley Periodicals, Inc.

  5. Sweat collection capsule

    Science.gov (United States)

    Greenleaf, J. E.; Delaplaine, R. W. (Inventor)

    1980-01-01

    A sweat collection capsule permitting quantitative collection of sweat is described. The device consists of a frame held immobile on the skin, a closure secured to the frame and absorbent material located next to the skin in a cavity formed by the frame and the closure. The absorbent material may be removed from the device by removing the closure from the frame while the frame is held immobile on the skin.

  6. [Amounts of sweat and salt loss due to sweating during a three-hour badminton practice in summer].

    Science.gov (United States)

    Hashimoto, Yoshiaki; Watanabe, Nobuko; Futamura, Azusa

    2007-11-01

    In 7 men and 5 women, we measured the amounts of sweat and fluid intake, and the ionic composition of sweat during a 3-hour badminton practice in summer. The amount of sweat was calculated as follows; body weight before practice (g)--body weight after practice (g)--urine volume (ml) +fluid intake (ml). We collected sweat by covering the non-dominant forearm with a plastic bag. The amounts of sweat and fluid intake during the 3-hour practice were 1809 +/- 715ml (mean +/- SD) and 658 +/- 344ml, respectively. Weight loss after the practice was 2.0 +/- 0.9% of their weight before the practice. The Na(+) and Cl(-) levels of the sweat about 30 min after the start of practice were 66 +/- 34 mEq/l and 54 +/- 32mEq/l, respectively. There was no significant difference between those ionic levels of the sweat about 30 min after the start of practice and those about 30 min before the end of practice. The sum of Na(+) and Cl(-) loss into sweat during a 3-hour practice session was supposed to be 6.9 +/- 5.3g, and to be above 10 g in 4 of 7 men, assuming that there were no regional differences in the ionic composition of sweat. The findings suggested that most of the participants should take more fluid and some of them might need salt intake during the practice.

  7. Elemental composition of muscle at rest and potassium levels in muscle, plasma and sweat of horses exercising at 20 degrees C and 35 degrees C.

    Science.gov (United States)

    Gottlieb-Vedi, M; Dahlborn, K; Jansson, A; Wroblewski, R

    1996-07-01

    In this study, 4 Standardbred geldings were exercised at 20 and 35 degrees C. The exercise test (ET) consisted of 2 exercise bouts separated by 2 h of rest in their boxes. Blood samples were taken before, during and after the second exercise bout and muscle (m. gluteus medius) biopsies were taken before the first exercise bout and after an intensive trot over 2600 m in the second exercise bout. The blood samples were analysed for plasma potassium and total plasma protein concentration (TPP) and the muscle fibres were analysed for elemental composition by x-ray microanalysis. The intracellular content was as follows: sodium (Na) = 40 +/- 7; magnesium (Mg) = 32 +/- 4; phosphorus (P) = 282 +/- 15; sulphur (S) = 222 +/- 13; chloride (Cl) = 119 +/- 31; potassium (K) = 304 +/- 21 and calcium (Ca) = 8 +/- 2 mmol/kg dry weight under resting conditions. Intracellular potassium content increased after exercise compared to resting values. There was a good correlation between exercise intensity, plasma potassium concentration and shifts in plasma volume, indicated by alterations in TPP. This probably reflects the very fast shift of potassium and fluid between muscle and plasma. Plasma potassium concentrations decreased below resting values post exercise. The higher dehydration degree and potassium sweat loss after exercise at 35 degrees C was not reflected in lower muscular potassium content, but by a lower plasma potassium/total plasma protein ratio after exercise, indicating less circulating potassium.

  8. Fluid and electrolyte intake and loss in elite soccer players during training.

    Science.gov (United States)

    Maughan, Ronald J; Merson, Stuart J; Broad, Nick P; Shirreffs, Susan M

    2004-06-01

    This study measured fluid balance during a 90-min preseason training session in the first team squad (24 players) of an English Premier League football team. Sweat loss was assessed from changes in body mass after correction for ingested fluids and urine passed. Sweat composition was measured by collection from patches attached to the skin at 4 sites. The weather was warm (24-29 degrees C), with moderate humidity (46-64%). The mean +/- SD body mass loss over the training session was 1.10+/- 0.43 kg, equivalent to a level of dehydration of 1.37 +/- 0.54% of the pre-training body mass. Mean fluid intake was 971 +/- 303 ml. Estimated total mean sweat loss was 2033 +/- 413 ml. Mean sweat electrolyte concentrations (mmol/L) were: sodium, 49 +/- 12; potassium, 6.0 +/- 1.3; chloride, 43 +/- 10. Total sweat sodium loss of 99+/- 24 mmol corresponds to a salt (sodium chloride) loss of 5.8 +/- 1.4 g. Mean urine osmolality measured on pre-training samples provided by the players was 666 +/- 311 mosmol/kg (n = 21). These data indicate that sweat losses of water and solute in football players in training can be substantial but vary greatly between players even with the same exercise and environmental conditions. Voluntary fluid intake also shows wide inter-individual variability and is generally insufficient to match fluid losses.

  9. Wearable Sensor System Powered by a Biofuel Cell for Detection of Lactate Levels in Sweat (Postprint)

    Science.gov (United States)

    2016-05-04

    lactate dehydrogenase; energy harvester (EH); micropotentiostat (MP) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT: SAR 18. NUMBER OF...Band-Aid like RFID sensor patches and temporary tattoo-based sensors have been developed for electrolyte and lactate sensing in sweat as part of on...2008. ISABEL’08. First International Symposium on. 2008. IEEE. 27. D. P. Rose et al., “Adhesive RFID sensor patch for monitoring of sweat electrolytes

  10. Sweat mineral-element responses during 7 h of exercise-heat stress.

    Science.gov (United States)

    Montain, Scott J; Cheuvront, Samuel N; Lukaski, Henry C

    2007-12-01

    Uncertainty exists regarding the effect of sustained sweating on sweat mineral-element composition. To determine the effect of multiple hours of exercise-heat stress on sweat mineral concentrations. Seven heat-acclimated subjects (6 males, 1 female) completed 5 x 60 min of treadmill exercise (1.56 m/s, 2% grade) with 20 min rest between exercise periods in 2 weather conditions (27 degrees C, 40% relative humidity, 1 m/s and 35 degrees C, 30%, 1 m/s). Sweat was collected from a sweat-collection pouch attached to the upper back during exercise bouts 1, 3, and 5. Mineral elements were determined by using inductively coupled plasma-emission spectrography. At 27 degrees C, sweat sodium (863 [563] microg/mL; mean [SD]), potassium (222 [48] microg/mL), calcium (16 [7]) microg/mL), magnesium (1265 [566] ng/mL), and copper (80 [56] ng/mL) remained similar to baseline over 7 h of exercise-heat stress, whereas sweat zinc declined 42-45% after the initial hour of exercise-heat stress (Ex1 = 655 [362], Ex3 = 382 [168], Ex5 = 355 [288] microg/mL, P sweat zinc at 35 degrees C when sweat rates were higher. Sweat rate had no effect on sweat trace-element composition. Sweat sodium, potassium, and calcium losses during multiple hours of sustained sweating can be predicted from initial sweat composition. Estimates of sweat zinc losses, however, will be overestimated if sweat zinc conservation is not accounted for in sweat zinc-loss estimates.

  11. A new percolation model for composite solid electrolytes and dispersed ionic conductors

    Science.gov (United States)

    Risyad Hasyim, Muhammad; Lanagan, Michael T.

    2018-02-01

    Composite solid electrolytes (CSEs) including conductor/insulator composites known as dispersed ionic conductors (DICs) have motivated the development of novel percolation models that describe their conductivity. Despite the long history, existing models lack in one or more key areas: (1) rigorous foundation for their physical theory, (2) explanation for non-universal conductor–insulator transition, (3) classification of DICs, and (4) extension to frequency-domain. This work describes a frequency-domain effective medium approximation (EMA) of a bond percolation model for CSEs. The EMA is derived entirely from Maxwell’s equations and contains basic microstructure parameters. The model was applied successfully to several composite systems from literature. Simulations and fitting of literature data address these key areas and illustrate the interplay between space charge layer properties and bulk microstructure.

  12. The effect of salt on the morphologies of compositionally asymmetric block copolymer electrolytes

    Science.gov (United States)

    Loo, Whitney; Maslyn, Jacqueline; Oh, Hee Jeung; Balsara, Nitash

    Block copolymer electrolytes are promising for applications in lithium metal solid-state batteries. Due to their ability to microphase separate into distinct morphologies, their ion transport and mechanical properties can be decoupled. The addition of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt to poly(styrene)-block-poly(ethylene oxide) (SEO) has been shown to increase microphase separation in symmetric block copolymer systems due to an increase in the effective interaction parameter (χeff) ; however the effect of block copolymer compositional asymmetry is not well-understood. The effect of compositional asymmetry on polymer morphology was investigated through small and wide angle X-ray scattering (SAXS/WAXS). The effective Flory-Huggins interaction parameter was extracted from the scattering profiles in order to construct a phase diagram to demonstrate the effect of salt and compositional asymmetry on block copolymer morphology.

  13. Polyvinylpyrrolidone/polyvinyl butyral composite as a stable binder for castable supercapacitor electrodes in aqueous electrolytes

    Science.gov (United States)

    Aslan, M.; Weingarth, D.; Herbeck-Engel, P.; Grobelsek, I.; Presser, V.

    2015-04-01

    Mixtures of polyvinylpyrrolidone/polyvinyl butyral (PVP/PVB) are attractive binders for the preparation of carbon electrodes for aqueous electrolyte supercapacitors. The use of PVP/PVB offers several key advantages: They are soluble in ethanol and can be used to spray coat or drain cast activated carbon (AC) electrodes directly on a current collector. Infrared spectroscopy and contact angle measurements show that the PVP-to-PVB ratio determines the degree of binder hydrophilicity. Within our study, the most favorable performance was obtained for AC electrodes with a composition of AC + 1.5 mass% PVP + 6.0 mass% PVB; such electrodes were mechanically stabile and water resistant with a PVP release of less than 5% of total PVP while PVB itself is water insoluble. Compared to when using PVDF, the specific surface area (SSA) of the assembled electrodes was 10% higher, indicating a reduced pore blocking tendency. A good electrochemical performance was observed in different aqueous electrolytes for composite electrodes with the optimized binder composition: 160 F g-1 at 1 A g-1 for 1 M H2SO4 and 6 M KOH and 120 F g-1 for 1 M NaCl. The capacitance was slightly reduced by 2.5% after cycling to 1.2 V with 1.28 A g-1 in 1 M NaCl for 10,000 times.

  14. Simple barcode system based on ionogels for real time pH-sweat monitoring

    OpenAIRE

    Benito-Lopez, Fernando; Coyle, Shirley; Byrne, Robert; O’Toole, Corinne; Barry, Caroline; Diamond, Dermot

    2010-01-01

    This paper presents the fabrication, characterization and the performance of a wearable, robust, flexible and disposable barcode system based on novel ionic liquid polymer gels (ionogels) for monitoring in real time mode the pH of the sweat generated during an exercise period. Up to now sweat analysis has been carried out using awkward methods of collecting sweat followed by laboratory analysis. The approach presented here can provide immediate feedback regarding sweat composition. The great ...

  15. Electrochemical energy storage in montmorillonite K10 clay based composite as supercapacitor using ionic liquid electrolyte.

    Science.gov (United States)

    Maiti, Sandipan; Pramanik, Atin; Chattopadhyay, Shreyasi; De, Goutam; Mahanty, Sourindra

    2016-02-15

    Exploring new electrode materials is the key to realize high performance energy storage devices for effective utilization of renewable energy. Natural clays with layered structure and high surface area are prospective materials for electrical double layer capacitors (EDLC). In this work, a novel hybrid composite based on acid-leached montmorillonite (K10), multi-walled carbon nanotube (MWCNT) and manganese dioxide (MnO2) was prepared and its electrochemical properties were investigated by fabricating two-electrode asymmetric supercapacitor cells against activated carbon (AC) using 1.0M tetraethylammonium tetrafluroborate (Et4NBF4) in acetonitrile (AN) as electrolyte. The asymmetric supercapacitors, capable of operating in a wide potential window of 0.0-2.7V, showed a high energy density of 171Whkg(-1) at a power density of ∼1.98kWkg(-1). Such high EDLC performance could possibly be linked to the acid-base interaction of K10 through its surface hydroxyl groups with the tetraethylammonium cation [(C2H5)4N(+) or TEA(+)] of the ionic liquid electrolyte. Even at a very high power density of 96.4kWkg(-1), the cells could still deliver an energy density of 91.1Whkg(-1) exhibiting an outstanding rate capability. The present study demonstrates for the first time, the excellent potential of clay-based composites for high power energy storage device applications. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Polystyrene-Al2O3 composite solid polymer electrolyte for lithium secondary battery.

    Science.gov (United States)

    Lim, Yu-Jeong; An, Yu-Ha; Jo, Nam-Ju

    2012-01-05

    In a common salt-in-polymer electrolyte, a polymer which has polar groups in the molecular chain is necessary because the polar groups dissolve lithium salt and coordinate cations. Based on the above point of view, polystyrene [PS] that has nonpolar groups is not suitable for the polymer matrix. However, in this PS-based composite polymer-in-salt system, the transport of cations is not by segmental motion but by ion-hopping through a lithium percolation path made of high content lithium salt. Moreover, Al2O3 can dissolve salt, instead of polar groups of polymer matrix, by the Lewis acid-base interactions between the surface group of Al2O3 and salt. Notably, the maximum enhancement of ionic conductivity is found in acidic Al2O3 compared with neutral and basic Al2O3 arising from the increase of free ion fraction by dissociation of salt. It was revealed that PS-Al2O3 composite solid polymer electrolyte containing 70 wt.% salt and 10 wt.% acidic Al2O3 showed the highest ionic conductivity of 9.78 × 10-5 Scm-1 at room temperature.

  17. Dielectric and electrical behaviours of polymeric (PEO/PVP):NaIO4 composite for solid electrolytes

    Science.gov (United States)

    Marinov, Y. G.; Hadjichristov, G. B.; Petrov, A. G.; Koduru, H. K.; Marino, L.; Scaramuzza, N.

    2017-01-01

    Composite material prepared from polyethylene oxide (PEO) and polyvinylpyrrolidone (PVP) doped with Sodium (meta)periodate (NaIO4) salt was studied by complex impedance spectroscopy at room temperature. The polymers PEO and PVP were mixed in a weight ratio 70:30 %, and the concentration of the embedded NaIO4 compound was 7.5 wt.%. The effect from NaIO4 filler on the dielectric permittivity of the three-component mixed system was analyzed in the frequency range 0.1 Hz - 1 MHz. As compared with the two-component polymer host PEO/PVP, a distinctly enhanced electrical and dielectrical response and an increase of the value of dielectric constant of the polymeric (PEO/PVP):NaIO4 composite were present. This suggests the potential of this material for soft electronics and applications such as solid electrolytes.

  18. Mixed solid device based on conducting polymer composite and polymer electrolyte

    Directory of Open Access Journals (Sweden)

    Neves Silmara

    2004-01-01

    Full Text Available Tetraethyl orthosilicate (TEOS derived sol-gel porous films have been utilized as template for the electrochemical polymerization of aniline. Polyaniline-silica composites were obtained and the redox behavior and charge/discharge capacities of a lithium polymeric battery using poly (dimethylsiloxane- co-ethylene oxide as gel polymeric electrolyte, were investigated. The composite presented a high initial capacity (140 mA h g-1 and a reversible capacity of 75 mA h g-1 after 100 charge/discharge cycles. The decrease in the specific capacity was attributed to an increase in charge transfer resistance and a decrease in the diffusion coefficient measured by electrochemical impedance spectroscopy.

  19. Compositional effect investigation by addition PEG, PEO plasticiser of LiBOB based solid polymer electrolyte for lithium ion batteries

    Science.gov (United States)

    Sabrina, Qolby; Ratri, Christin Rina

    2017-08-01

    Development polymer electrolyte with high ionic conductivity is main of object in solid state electrolyte will be potential application as electrolyte batteries. Casting method have been used to prepared solid polymer electrolyte. Adding polyethylene(glycol) PEG and Poly(ethylene oxide) PEO as polymer matrix be made of poly(vinylidene fluoride) (PVdF) and lithium bis(oxalato) borate (LiBOB) to improve structure morphology and impedance characterization of solid electrolyte. The ratio of PEG and PEO is varied to study effect on the conductivity. Electro impedance spectroscopy (EIS) studies are carried out on the prepared samples. The impedance measurement show that the conductivity with composition PVdF- PEG- LiBOB 10% better than the other varieties to applied as solid electrolyte batteries. SEM morphology PVdF- PEG- LiBOB 10% sample showed the low crystallinity was caused by interaction between lithium salt and polymer. With their properties the solid polymer electrolyte are considered as promising candidates of applications for lithium ion batteries.

  20. Synthesis and characterization of polyvinyl alcohol copolymer/phosphomolybdic acid-based crosslinked composite polymer electrolyte membranes

    Science.gov (United States)

    Anis, Arfat; Banthia, A. K.; Bandyopadhyay, S.

    Polymer electrolyte membrane fuel cells (PEMFCs) are very promising as future energy source due to their high-energy conversion efficiency and will help to solve the environmental concerns of energy production. Polymer electrolyte membrane (PEM) is recognised as the key element for an efficient PEMFC. Chemically crosslinked composite membranes consisting of a poly(vinyl alcohol-co-vinyl acetate-co-itaconic acid) (PVACO) and phosphomolybdic acid (PMA) have been prepared by solution casting and evaluated as proton conducting polymer electrolytes. The proton conductivity of the membranes is investigated as a function of PMA composition, crosslinking density and temperature. The membranes have also been characterized by FTIR spectroscopy, TGA, AFM and TEM. The proton conductivity of the composite membranes is of the order of 10 -3 S cm -1 and shows better resistance to methanol permeability than Nafion 117 under similar measurement conditions.

  1. Sweat sodium loss influences serum sodium concentration in a marathon.

    Science.gov (United States)

    Lara, B; Salinero, J J; Areces, F; Ruiz-Vicente, D; Gallo-Salazar, C; Abián-Vicén, J; Del Coso, J

    2017-02-01

    The aim of this investigation was to determine the influence of sweat electrolyte concentration on body water and electrolyte homeostasis during a marathon. Fifty-one runners completed a marathon race in a warm and dry environment (24.4 ± 3.6 °C). Runners were classified as low-salt sweaters (n = 21; sweat Na + concentration), typical sweaters (n = 20; ≥30 and sweat Na + concentration), and salty sweaters (n = 10; ≥60 mmol/L of sweat Na + concentration). Before and after the race, body mass and a sample of venous blood were obtained. During the race, sweat samples were collected by using sweat patches, and fluid and electrolyte intake were recorded by using self-reported questionnaires. Low-salt, typical and salty sweaters presented similar sweat rates (0.93 ± 0.2, 0.92 ± 0.29, 0.99 ± 0.21 L/h, respectively), body mass changes (-3.0 ± 1.0, -3.3 ± 1.0, -3.2 ± 0.8%), total Na + intake (12.7 ± 8.1, 11.5 ± 9.7, 14.5 ± 16.6 mmol), and fluid intake (1.3 ± 0.8, 1.2 ± 0.8, 1.2 ± 0.6 L) during the race. However, salty sweaters presented lower post-race serum Na + concentration (140.8 ± 1.3 vs 142.5 ± 1.1, 142.4 ± 1.4 mmol/L; P Sweat electrolyte concentration could influence post-race serum electrolyte concentration in the marathon. However, even the saltiest sweaters did not develop exercise-associated hyponatremia or associated symptoms. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Effect of ethnicity, gender and age on the amount and composition of residual skin surface components derived from sebum, sweat and epidermal lipids.

    Science.gov (United States)

    Shetage, Satyajit S; Traynor, Matthew J; Brown, Marc B; Raji, Mahad; Graham-Kalio, Diepiriye; Chilcott, Robert P

    2014-02-01

    The superficial layer on the skin surface, known as the acid mantle, comprises a mixture of sebum, sweat, corneocyte debris and constituents of natural moisturizing factor. Thus, the phrase 'residual skin surface components' (RSSC) is an appropriate term for the mixture of substances recovered from the skin surface. There is no general agreement about the effects of ethnicity, gender and age on RSSC. The aim of this human volunteer study was to evaluate RSSC in relation to ethnicity, gender and age. A suitable acquisition medium for RSSC collection was identified and samples of RSSC were subsequently analysed using gas chromatography-mass spectrometry (GC-MS) and gravimetry. A total of 315 volunteers participated in the study from a range of self-declared ethnic backgrounds. Six acquisition media were compared to determine the most suitable media for RSSC collection. The effect of age, gender and ethnicity on RSSC collection was evaluated by gravimetric analysis while GC-MS was used to determine the composition of RSSC. Of the six candidate materials assessed, cigarette paper provided the most practical and reproducible sample acquisition medium. There was no significant difference in the amount of RSSC collected when based on gender and ethnicity and no significant correlation between RSSC recovery and age. Up to 49 compounds were detected from human RSSC when analysed by GC-MS. The results of the present study suggest that RSSC can be effectively collected using cigarette paper and analysed by GC-MS. Ethnicity, gender and age had no significant impact on the quantity of RSSC recovered from the skin surface. © 2013 The Authors. Skin Research and Technology published by John Wiley & Sons Ltd.

  3. A graphite-coated carbon fiber epoxy composite bipolar plate for polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Yu, Ha Na; Lim, Jun Woo; Suh, Jung Do; Lee, Dai Gil

    A PEMFC (polymer electrolyte membrane fuel cell or proton exchange membrane fuel cell) stack is composed of GDLs (gas diffusion layers), MEAs (membrane electrode assemblies), and bipolar plates. One of the important functions of bipolar plates is to collect and conduct the current from cell to cell, which requires low electrical bulk and interfacial resistances. For a carbon fiber epoxy composite bipolar plate, the interfacial resistance is usually much larger than the bulk resistance due to the resin-rich layer on the composite surface. In this study, a thin graphite layer is coated on the carbon/epoxy composite bipolar plate to decrease the interfacial contact resistance between the bipolar plate and the GDL. The total electrical resistance in the through-thickness direction of the bipolar plate is measured with respect to the thickness of the graphite coating layer, and the ratio of the bulk resistance to the interfacial contact resistance is estimated using the measured data. From the experiment, it is found that the graphite coating on the carbon/epoxy composite bipolar plate has 10% and 4% of the total electrical and interfacial contact resistances of the conventional carbon/epoxy composite bipolar plate, respectively, when the graphite coating thickness is 50 μm.

  4. Aluminium in human sweat.

    Science.gov (United States)

    Minshall, Clare; Nadal, Jodie; Exley, Christopher

    2014-01-01

    It is of burgeoning importance that the human body burden of aluminium is understood and is measured. There are surprisingly few data to describe human excretion of systemic aluminium and almost no reliable data which relate to aluminium in sweat. We have measured the aluminium content of sweat in 20 healthy volunteers following mild exercise. The concentration of aluminium ranged from 329 to 5329μg/L. These data equate to a daily excretion of between 234 and 7192μg aluminium and they strongly suggest that perspiration is the major route of excretion of systemic aluminium in humans. Copyright © 2013 Elsevier GmbH. All rights reserved.

  5. On sweat analysis for quantitative estimation of dehydration during physical exercise.

    Science.gov (United States)

    Ring, Matthias; Lohmueller, Clemens; Rauh, Manfred; Eskofier, Bjoern M

    2015-08-01

    Quantitative estimation of water loss during physical exercise is of importance because dehydration can impair both muscular strength and aerobic endurance. A physiological indicator for deficit of total body water (TBW) might be the concentration of electrolytes in sweat. It has been shown that concentrations differ after physical exercise depending on whether water loss was replaced by fluid intake or not. However, to the best of our knowledge, this fact has not been examined for its potential to quantitatively estimate TBW loss. Therefore, we conducted a study in which sweat samples were collected continuously during two hours of physical exercise without fluid intake. A statistical analysis of these sweat samples revealed significant correlations between chloride concentration in sweat and TBW loss (r = 0.41, p sweat osmolality and TBW loss (r = 0.43, p sweat samples.

  6. Synthesis and characterization of ion transport behavior in Cu2+-conducting nano composite polymer electrolyte membranes

    Science.gov (United States)

    Bala Sahu, Tripti; Sahu, Manju; Karan, Shrabani; Mahipal, Y. K.; Sahu, D. K.; Agrawal, R. C.

    2017-07-01

    Synthesis and characterization of ion transport behavior in Cu2+-conducting nano composite polymer electrolyte (NCPE) films: [90PEO: 10Cu(CF3SO3)2]  +  x CuO have been reported. NCPE films have been formed by hot-press casting technique using solid polymer electrolyte (SPE) film composition: [90PEO: 10Cu(CF3SO3)2] as 1st-phase host and nanoparticles of CuO in varying wt.(%) as 2nd-phase active filler. SPE: [90PEO: 10Cu(CF3SO3)2] was identified earlier as highest conducting film with room temperature conductivity (σ rt) ~ 3.0 x 10-6 S cm-1, which is three orders of magnitude higher than that of pure polymer host PEO with σ rt ~ 3.2  ×  10-9 S cm-1. Filler particle concentration dependent conductivity study revealed NCPE film: [90PEO: 10Cu(CF3SO3)2]  +  3%CuO as optimum conducting composition (OCC) exhibiting σ rt ~ 1.14  ×  10-5 S cm-1. Hence, by the fractional dispersal of 2nd-phase active filler into 1st-phase SPE host, σ-enhancement of approximately an order of magnitude has further been obtained. Ion transport behavior in NCPE OCC film has been characterized in terms of basic ionic parameters viz. ionic conductivity (σ), total ionic transference (t ion)/cationic (t +) numbers. Temperature dependent conductivity measurement has also been done to explain the mechanism of ion transport and to compute activation energy (E a). Materials characterization and hence, confirmation of complexation of salt in polymeric host and/or dispersal of filler particles in SPE host have been done by scanning electron microscopy (SEM), energy dispersive x-ray spectrometer (EDS), x-ray diffraction (XRD), Fourier transform infra-red (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). All-solid-state battery in the cell configuration: Cu (Anode) || SPE host/NCPE OCC film || C  +  I2  +  Electrolyte) (Cathode) has been fabricated and cell performance has been studied under two load resistances viz

  7. All-solid-state lithium organic battery with composite polymer electrolyte and pillar[5]quinone cathode.

    Science.gov (United States)

    Zhu, Zhiqiang; Hong, Meiling; Guo, Dongsheng; Shi, Jifu; Tao, Zhanliang; Chen, Jun

    2014-11-26

    The cathode capacity of common lithium ion batteries (LIBs) using inorganic electrodes and liquid electrolytes must be further improved. Alternatively, all-solid-state lithium batteries comprising the electrode of organic compounds can offer much higher capacity. Herein, we successfully fabricated an all-solid-state lithium battery based on organic pillar[5]quinone (C35H20O10) cathode and composite polymer electrolyte (CPE). The poly(methacrylate) (PMA)/poly(ethylene glycol) (PEG)-LiClO4-3 wt % SiO2 CPE has an optimum ionic conductivity of 0.26 mS cm(-1) at room temperature. Furthermore, pillar[5]quinine cathode in all-solid-state battery rendered an average operation voltage of ∼2.6 V and a high initial capacity of 418 mAh g(-1) with a stable cyclability (94.7% capacity retention after 50 cycles at 0.2C rate) through the reversible redox reactions of enolate/quinonid carbonyl groups, showing favorable prospect for the device application with high capacity.

  8. Composite Gel Polymer Electrolyte for Improved Cyclability in Lithium-Oxygen Batteries.

    Science.gov (United States)

    Chamaani, Amir; Safa, Meer; Chawla, Neha; El-Zahab, Bilal

    2017-10-04

    Gel polymer electrolytes (GPE) and composite GPE (cGPE) using one-dimensional glass microfillers have been developed for their use in lithium-oxygen batteries. Using glass microfillers, tetraglyme solvent, UV-curable polymer, and lithium salt at various concentrations, the preparation of cGPE yielded free-standing films. These cGPEs, with 1 wt % of microfillers, demonstrated increased ionic conductivity and lithium transference number over GPEs at various concentrations of lithium salt. Improvements as high as 50% and 28% in lithium transference number were observed for 0.1 and 1.0 mol kg-1 salt concentrations, respectively. Lithium-oxygen batteries containing cGPE similarly showed superior charge/discharge cycling for 500 mAh g-1 cycle capacity with as high as 86% and 400% increase in cycles for cGPE with 1.0 and 0.1 mol kg-1 over GPE. Results using electrochemical impedance spectroscopy, Raman spectroscopy, and scanning electron microscopy revealed that the source of the improvement was the reduction of the rate of lithium carbonates formation on the surface of the cathode. This reduction in formation rate afforded by cGPE-containing batteries was possible due to the reduction of the rate of electrolyte decomposition. The increase in solvated to paired Li+ ratio at the cathode, afforded by increased lithium transference number, helped reduce the probability of superoxide radicals reacting with the tetraglyme solvent. This stabilization during cycling helped prolong the cycling life of the batteries.

  9. [What causes English sweats?].

    Science.gov (United States)

    Rimar, Yossi

    2004-09-01

    English sweating disease also known as Sudor Anglicus is one of the least familiar epidemics of the Middle Ages, striking England 5 times during the 15th and 16th centuries before fading. This article will discuss the knowledge available to us about this fascinating epidemic, its characteristics and causes.

  10. Hyperhidrosis (Excessive Sweating)

    Science.gov (United States)

    ... medicines also can cause this type of hyperhidrosis. Anxiety and embarrassment Both types of hyperhidrosis can cause people to feel extremely anxious and embarrassed. Students often avoid raising their hand during class. Many teens never date. Adults may hide the sweat stains ...

  11. Electrolyte for batteries with regenerative solid electrolyte interface

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jie; Lu, Dongping; Shao, Yuyan; Bennett, Wendy D.; Graff, Gordon L.; Liu, Jun; Zhang, Ji-Guang

    2017-08-01

    An energy storage device comprising: an anode; and a solute-containing electrolyte composition wherein the solute concentration in the electrolyte composition is sufficiently high to form a regenerative solid electrolyte interface layer on a surface of the anode only during charging of the energy storage device, wherein the regenerative layer comprises at least one solute or solvated solute from the electrolyte composition.

  12. 3D modeling and characterization of a calorimetric flow rate sensor for sweat rate sensing applications

    Science.gov (United States)

    Iftekhar, Ahmed Tashfin; Ho, Jenny Che-Ting; Mellinger, Axel; Kaya, Tolga

    2017-03-01

    Sweat-based physiological monitoring has been intensively explored in the last decade with the hopes of developing real-time hydration monitoring devices. Although the content of sweat (electrolytes, lactate, urea, etc.) provides significant information about the physiology, it is also very important to know the rate of sweat at the time of sweat content measurements because the sweat rate is known to alter the concentrations of sweat compounds. We developed a calorimetric based flow rate sensor using PolydimethylSiloxane that is suitable for sweat rate applications. Our simple approach on using temperature-based flow rate detection can easily be adapted to multiple sweat collection and analysis devices. Moreover, we have developed a 3D finite element analysis model of the device using COMSOL Multiphysics™ and verified the flow rate measurements. The experiment investigated flow rate values from 0.3 μl/min up to 2.1 ml/min, which covers the human sweat rate range (0.5 μl/min-10 μl/min). The 3D model simulations and analytical model calculations covered an even wider range in order to understand the main physical mechanisms of the device. With a verified 3D model, different environmental heat conditions could be further studied to shed light on the physiology of the sweat rate.

  13. Robust High-performance Dye-sensitized Solar Cells Based on Ionic Liquid-sulfolane Composite Electrolytes

    Science.gov (United States)

    Lau, Genevieve P. S.; Décoppet, Jean-David; Moehl, Thomas; Zakeeruddin, Shaik M.; Grätzel, Michael; Dyson, Paul J.

    2015-01-01

    Novel ionic liquid-sulfolane composite electrolytes based on the 1,2,3-triazolium family of ionic liquids were developed for dye-sensitized solar cells. The best performing device exhibited a short-circuit current density of 13.4 mA cm−2, an open-circuit voltage of 713 mV and a fill factor of 0.65, corresponding to an overall power conversion efficiency (PCE) of 6.3%. In addition, these devices are highly stable, retaining more than 95% of the initial device PCE after 1000 hours of light- and heat-stress. These composite electrolytes show great promise for industrial application as they allow for a 14.5% improvement in PCE, compared to the solvent-free eutectic ionic liquid electrolyte system, without compromising device stability. PMID:26670595

  14. Fe-doped 8YSZ at different composition for solid electrolyte in solid oxide fuel cell

    Directory of Open Access Journals (Sweden)

    Johar B.

    2016-01-01

    Full Text Available Pure 8 mol% yttria stabilized zirconia (YSZ and Fe-doped (1 mol%, 2 mol% and 3 mol% YSZ electrolyte were prepared and sintered at 1550°C. Transition metal oxide is added into YSZ as sintering aided has a function to reduce the sintering temperature. The microstructure, crystal structure and ionic conductivity of pure YSZ and Fe-doped YSZ at different composition were investigated. The amount of cubic phase decreased as the amount of Fe increased. Fe-doped 8YSZ had higher conductivity than pure 8YSZ. The ionic conductivity of 3FeYSZ is 9.35×10−8 S/cm higher than 1FeYSZ which is 4.72×10−9 S/cm when operated at 300°C.

  15. Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

    OpenAIRE

    Meyer,F.; Laitano,O.; Bar-Or,O.; McDougall,D.; Heigenhauser,G.J.F.

    2007-01-01

    The dependence of sweat composition and acidity on sweating rate (SR) suggests that the lower SR in children compared to adults may be accompanied by a higher level of sweat lactate (Lac-) and ammonia (NH3) and a lower sweat pH. Four groups (15 girls, 18 boys, 8 women, 8 men) cycled in the heat (42ºC, 20% relative humidity) at 50% VO2max for two 20-min bouts with a 10-min rest before bout 1 and between bouts. Sweat was collected into plastic bags attached to the subject's lower back. During b...

  16. Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

    OpenAIRE

    Meyer, Flavia; Lionello Neto, Orlando Laitano

    2007-01-01

    The dependence of sweat composition and acidity on sweating rate (SR) suggests that the lower SR in children compared to adults may be accompanied by a higher level of sweat lactate (Lac-) and ammonia (NH3) and a lower sweat pH. Four groups (15 girls, 18 boys, 8 women, 8 men) cycled in the heat (42ºC, 20% relative humidity) at 50% VO2max for two 20-min bouts with a 10-min rest before bout 1 and between bouts. Sweat was collected into plastic bags attached to the subject’s lower back. During b...

  17. THE INVESTIGATION OF INFLUENCE OF LASER RADIATION ON THE STRUCTURE AND MECHANICAL PROPERTIES OF COMPOSITE ELECTROLYTIC NICKEL COATING

    Directory of Open Access Journals (Sweden)

    V. A. Zabludovsky

    2013-09-01

    Full Text Available Purpose. Investigation of laser radiation effect on the structure and mechanical properties of electrodeposited nickel composite coatings containing ultrafine diamonds. Methodology. Electrodeposition of nickel films was carried out with the addition of a standard solution of ultrafine diamonds (UFD on laser-electrolytic installation, built on the basis of the gas-discharge CO2 laser. Mechanical testing the durability of coatings were performed on a machine with reciprocating samples in conditions of dry friction against steel. The spectral microanalysis of the elemental composition of the film - substrate was performed on REMMA-102-02. Findings. Research of nickel coatings and modified ultrafine diamond electrodeposited under external stimulation laser demonstrated the dependence of the structure and mechanical properties of composite electrolytic coating (CEC, and the qualitative and quantitative distribution of nanodiamond coprecipitated from an electrodeposition method. Originality. The effect of laser light on the process of co-precipitation of the UFD, which increases the micro-hardness and wear resistance of electrolytic nickel coatings was determined. Practical value. The test method of laser-stimulated composite electrolytic nickel electrodeposition coating is an effective method of local increase in wear resistance of metal coatings, which provides durability save performance (functional properties of the surface.

  18. New Class of LAGP-Based Solid Polymer Composite Electrolyte for Efficient and Safe Solid-State Lithium Batteries.

    Science.gov (United States)

    Guo, Qingpeng; Han, Yu; Wang, Hui; Xiong, Shizhao; Li, Yujie; Liu, Shuangke; Xie, Kai

    2017-12-06

    Inorganic solid electrolytes (SEs) possess substantial safety and electrochemical stability, which make them as key components of safe rechargeable solid-state Li batteries with high energy density. However, complicated integrally molding process and poor wettability between SEs and active materials are the most challenging barriers for the application of SEs. In this regard, we explore composite SEs of the active ceramic Li1+xAlxGe2-x(PO4)3 (LAGP) as the main medium for ion conduction and the polymer P(VDF-HFP) as a matrix. Meanwhile, for the first time, we choice high chemical, thermal, and electrochemical stability of ionic liquid swelled in polymer, which significantly ameliorate the interface in the cell. In addition, a reduced crystallinity degree of the polymer in the electrolyte can also be achieved. All of these lead to good ionic conductivity of the composite electrolyte (LPELCE), at the same time, good compatibility with the lithium electrode. Especially, high mechanical strength and stable solid electrolyte interphase which suppressed the growth of lithium dendrites and high thermal safety stability can also be observed. For further illustration, the solid-state lithium battery of LiFePO4/LPELCE/Li shows relatively satisfactory performance, indicating the promising potentials of using this type of electrolyte to develop high safety and high energy density solid-state lithium batteries.

  19. High temperature operation of a composite membrane-based solid polymer electrolyte water electrolyser

    Energy Technology Data Exchange (ETDEWEB)

    Antonucci, V.; Di Blasi, A.; Baglio, V.; Arico, A.S. [CNR-ITAE, Via Salita S. Lucia sopra Contesse 5, 98126 Messina (Italy); Ornelas, R.; Matteucci, F. [Tozzi Apparecchiature Elettriche SpA, Via Zuccherificio, 10-48010 Mezzano (RA) (Italy); Ledesma-Garcia, J.; Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Parque Tecnologico Queretaro, Sanfandila, Pedro Escobedo, C.P. 76703 Queretaro (Mexico)

    2008-10-15

    The high temperature behaviour of a solid polymer electrolyte (SPE) water electrolyser based on a composite Nafion-SiO{sub 2} membrane was investigated and compared to that of a commercial Nafion membrane. The SPE water electrolyser performance was studied from 80 to 120{sup o}C with an operating pressure varying between 1 and 3 bar abs. IrO{sub 2} and Pt were used as oxygen and hydrogen evolution catalysts, respectively. The assemblies were manufactured by using a catalyst-coated membrane (CCM) technique. The performance was significantly better for the composite Nafion-SiO{sub 2} membrane than commercial Nafion 115. Furthermore, the composite membrane allowed suitable water electrolysis at high temperature under atmospheric pressure. The current densities were 2 and 1.2 A cm{sup -2} at a terminal voltage of 1.9 V for Nafion-SiO{sub 2} and Nafion 115, respectively, at 100{sup o}C and atmospheric pressure. By increasing the temperature up to 120{sup o}C, the performance of Nafion 115 drastically decreased; whereas, the cell based on Nafion-SiO{sub 2} membrane showed a further increase of performance, especially when the pressure was increased to 3 bar abs (2.1 A cm{sup -2} at 1.9 V). (author)

  20. Hydrochromic Approaches to Mapping Human Sweat Pores.

    Science.gov (United States)

    Park, Dong-Hoon; Park, Bum Jun; Kim, Jong-Man

    2016-06-21

    colorimetric change near body temperature. This feature enables the use of this technique to generate high-quality images of sweat pores. This Account also focuses on the results of the most recent phase of this investigation, which led to the development of a simple yet efficient and reliable technique for sweat pore mapping. The method utilizes a hydrophilic polymer composite film containing fluorescein, a commercially available dye that undergoes a fluorometric response as a result of water-dependent interconversion between its ring-closed spirolactone (nonfluorescent) and ring-opened fluorone (fluorescent) forms. Surface-modified carbon nanodots (CDs) have also been found to be efficient for hydrochromic mapping of human sweat pores. The results discovered by Lou et al. [ Adv. Mater. 2015 , 27 , 1389 ] are also included in this Account. Sweat pore maps obtained from fingertips using these materials were found to be useful for fingerprint analysis. In addition, this hydrochromism-based approach is sufficiently sensitive to enable differentiation between sweat-secreting active pores and inactive pores. As a result, the techniques can be applied to clinical diagnosis of malfunctioning sweat pores. The directions that future research in this area will follow are also discussed.

  1. Impact resistant electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Veith, Gabriel M.; Armstrong, Beth L.; Tenhaeff, Wyatt E.; Dudney, Nancy J.

    2017-03-07

    A passively impact resistant composite electrolyte composition includes an electrolyte solvent, up to 2M of an electrolyte salt, and shear thickening ceramic particles having a polydispersity index of no greater than 0.1, an average particle size of in a range of 50 nm to 1 .mu.m, and an absolute zeta potential of greater than .+-.40 mV.

  2. Improved Composite Gel Electrolyte by Layered Vermiculite for Quasi-Solid-State Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Hongcai He

    2014-01-01

    Full Text Available A composite quasisolid electrolyte is prepared by adding a layered vermiculite (VMT into the iodide/triiodide electrolyte including 4-tert-butylpyridine, which obviously improves the photovoltaic properties of quasisolid dye-sensitized solar cells (DSSCs. When adding 6 wt% VMT, the maximum photovoltaic conversion efficiency of 3.89% is obtained, which reaches more than two times greater than that without VMT. This enhancement effect is primarily explained by studying the Nyquist spectra, dark currents, and photovoltaic conversion efficiency.

  3. Composite plasma electrolytic oxidation to improve the thermal radiation performance and corrosion resistance on an Al substrate

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Donghyun [Department of Materials Science and Engineering, Pusan National University, Busan 46241 (Korea, Republic of); Sung, Dahye [Department of Materials Science and Engineering, Pusan National University, Busan 46241 (Korea, Republic of); Korea Institute of Industrial Technology (KITECH), Busan 46742 (Korea, Republic of); Lee, Junghoon [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Kim, Yonghwan [Korea Institute of Industrial Technology (KITECH), Busan 46742 (Korea, Republic of); Chung, Wonsub, E-mail: wschung1@pusan.ac.kr [Department of Materials Science and Engineering, Pusan National University, Busan 46241 (Korea, Republic of)

    2015-12-01

    Highlights: • Composite plasma electrolytic oxidation was performed using dispersed CuO particles in convectional PEO electrolyte. • Thermal radiation performance and corrosion resistance were examined by FT-IR spectroscopy and electrochemical methods, respectively. • Deposited copper oxide on the surface of the Al substrate was enhanced the corrosion resistance and the emissivity compared with the conventional PEO. - Abstract: A composite plasma electrolytic oxidation (PEO) was performed for enhancing the thermal radiation performance and corrosion resistance on an Al alloy by dispersing cupric oxide (CuO) particles in a conventional PEO electrolyte. Cu-based oxides (CuO and Cu{sub 2}O) formed by composite PEO increased the emissivity of the substrate to 0.892, and made the surface being dark color, similar to a black body, i.e., an ideal radiator. In addition, the corrosion resistance was analyzed using potentio-dynamic polarization and electrochemical impedance spectroscopy tests in 3.5 wt.% NaCl aqueous solution. An optimum condition of 10 ampere per square decimeter (ASD) current density and 30 min processing time produced appropriate surface morphologies and coating thicknesses, as well as dense Cu- and Al-based oxides that constituted the coating layers.

  4. Semi-Interpenetrating Polymer Network Composite Gel Electrolytes Employing Vinyl-Functionalized Silica for Lithium-Oxygen Batteries with Enhanced Cycling Stability.

    Science.gov (United States)

    Woo, Hyun-Sik; Moon, Yong-Bok; Seo, Samuel; Lee, Ho-Taek; Kim, Dong-Won

    2018-01-10

    A major challenge of lithium-oxygen batteries is to develop a stable electrolyte not only to suppress solvent evaporation and lithium dendrite growth, but also to resist the attack by superoxide anion radical formed at the positive electrode. The present study demonstrates the enhancement of cycling stability by addressing the above challenges through the use of three-dimensional semi-interpenetrating polymer network (semi-IPN) composite gel polymer electrolyte when fabricating the lithium-oxygen cell. The semi-IPN composite gel electrolyte synthesized from poly(methyl methacrylate), divinylbenzene, and vinyl-functionalized silica effectively encapsulated electrolyte solution and exhibited stable interfacial characteristics toward lithium electrodes. Matrix polymers in the semi-IPN composite gel electrolyte also retained high stability without any decomposition by superoxide anion radicals during cycling. The lithium-oxygen cell employing semi-IPN composite gel polymer electrolyte was shown to cycle with good capacity retention at 0.25 mAh cm-2. The semi-IPN composite gel electrolyte is one of the promising electrolytes for the stable lithium-oxygen battery with high energy density.

  5. Ninhydrin sweat test in leprosy.

    Science.gov (United States)

    Markendeya, N; Srinivas, C R

    2004-01-01

    Loss of sensation is an important feature of leprosy. Loss of sweating over the affected site due to loss of autonomic function occurs in leprosy. We have studied a simple, non-invasive, rapid method, using 1% ninhydrin in acetone, to detect loss of sweat function. The test was effective in detecting and grading the sweat function in 84 cases of different types of leprosy. We were able to detect normal sweating in 16 patients with hypopigmented lesion due to causes other than Hansen's disease.

  6. Electrolytic Production of Ti5Si3/TiC Composites by Solid Oxide Membrane Technology

    Science.gov (United States)

    Zheng, Kai; Zou, Xingli; Xie, Xueliang; Lu, Changyuan; Chen, Chaoyi; Xu, Qian; Lu, Xionggang

    2018-02-01

    This paper investigated the electrolytic production of Ti5Si3/TiC composites from TiO2/SiO2/C in molten CaCl2. The solid-oxide oxygen-ion-conducting membrane tube filled with carbon-saturated liquid tin was served as the anode, and the pressed spherical TiO2/SiO2/C pellet was used as the cathode. The electrochemical reduction process was carried out at 1273 K and 3.8 V. The characteristics of the obtained cathode products and the reaction mechanism of the electroreduction process were studied by a series of time-dependent electroreduction experiments. It was found that the electroreduction process generally proceeds through the following steps: TiO2/SiO2/C → Ti2O3, CaTiO3, Ca2SiO4, SiC → Ti5Si3, TiC. The morphology observation and the elemental distribution analysis indicate that the reaction routes for Ti5Si3 and TiC products are independent during the electroreduction process.

  7. [Morphological characteristics and intracellular electrolytic composition of blood cells at surgeries on lower extremities arteries].

    Science.gov (United States)

    Katel'nitskiĭ, I I; Dudarev, I V; Matsionis, A E; Povilaĭtite, P E; Kvitko, I A

    2007-01-01

    Morphological characteristics and trace and macroelement composition of blood cells flowing out of ischemic lower limb before, during and after reconstructive surgeries under different type of anesthesia. A total of 102 male patients aged 45 to 60 years with atherosclerotic occlusions of the arteries of the femoral-popliteal zone were included into the study. According to anesthesia type all the patients were divided into 3 groups: group 1 consisted of 34 patients operated under spinal anesthesia, 37 patients of group 2 underwent surgery under combined anesthesia (spinal anesthesia with intravenous sedation), 31 patients of group 3 - under total intravenous anesthesia with myoplegia and artificial pulmonary ventilation. All the blood examinations were carried out with scanning electron microscope XL-30 ("Philips") and X-ray spectrum microanalyzer Edax ( "Edax International", USA). It is demonstrated that in spinal and combined anesthesia morphological characteristics of blood cells normalized due to optimization of intraerythrocytic and intrathrombocytic electrolytic homeostasis unlike total intravenous anesthesia, when intracellular imbalance of trace and macroelements progresses and ultrastructural cellular alterations persist.

  8. Polybenzimidazole/Mxene composite membranes for intermediate temperature polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Fei, Mingming; Lin, Ruizhi; Deng, Yuming; Xian, Hongxi; Bian, Renji; Zhang, Xiaole; Cheng, Jigui; Xu, Chenxi; Cai, Dongyu

    2018-01-01

    This report demonstrated the first study on the use of a new 2D nanomaterial (Mxene) for enhancing membrane performance of intermediate temperature (>100 °C) polymer electrolyte membrane fuel cells (ITPEMFCs). In this study, a typical Ti3C2T x -MXene was synthesized and incorporated into polybenzimidazole (PBI)-based membranes by using a solution blending method. The composite membrane with 3 wt% Ti3C2T x -MXene showed the proton conductivity more than 2 times higher than that of pristine PBI membrane at the temperature range of 100 °C–170 °C, and led to substantial increase in maximum power density of fuel cells by ∼30% tested at 150 °C. The addition of Ti3C2T x -MXene also improved the mechanical properties and thermal stability of PBI membranes. At 3 wt% Ti3C2T x -MXene, the elongation at break of phosphoric acid doped PBI remained unaffected at 150 °C, and the tensile strength and Young’s modulus was increased by ∼150% and ∼160%, respectively. This study pointed out promising application of MXene in ITPEMFCs.

  9. Electrochemical behavior of nanostructured MnO2/C (Vulcan® composite in aqueous electrolyte LiNO3

    Directory of Open Access Journals (Sweden)

    Vujković Milica

    2011-01-01

    Full Text Available The electrolytic solutions of contemporary Li-ion batteries are made exclusively with the organic solvents since anodic materials of these batteries have potentials with greater negativity than the potential of the water reduction, thus the organic electrolytes can withstand the voltages of 3-5 V that are characteristic for these batteries. Ever since it was discovered that some materials can electrochemically intercalate and deintercalate Li+ ions in aqueous solutions, numerous studies have been conducted with the aim of extending operational time of the aqueous Li-ion batteries. Manganese oxide has been studied as the electrode material in rechargeable lithium-ion batteries with organic electrolytes. In this paper its electrochemical behavior as an anode material in aqueous electrolyte solutions was examined. MnO2 as a component of nanodispersed MnO2/C (Vulcan® composite was successfully synthesized hydrothermally. Electrochemical properties of this material were investigated in aqueous saturated LiNO3 solution by both cyclic voltammetry and galvanostatic charging/discharging (LiMn2O4 as cathode material techniques. The obtained composite shows a relatively good initial discharge capacity of 96.5 mAh/g which, after 50th charging/discharging cycles, drops to the value of 57mAh/g. MnO2/C (Vulcan® composite, in combination with LiMn2O4 as a cathode material, shows better discharge capacity compared to other anodic materials used in aqueous Li-ion batteries according to certain studies that have been conducted. Its good reversibility and cyclability, and the fact that hydrothermal method is simple and effective, makes MnO2/C(Vulcan® composite a promising anodic material for aqueous Li-ion batteries.

  10. Sweating dysfunction in Parkinson's disease

    NARCIS (Netherlands)

    Swinn, L; Schrag, A; Viswanathan, R; Lees, A; Quinn, N; Bloem, Bastiaan R.

    2003-01-01

    We sought to determine the prevalence and nature of sweating disturbances in patients with Parkinson's disease (PD), and investigated their correlation with other clinical features and with Quality of Life (QoL) measures. A questionnaire on symptoms and consequences of sweating dysfunction was

  11. Metabolomics analysis of human sweat collected after moderate exercise.

    Science.gov (United States)

    Delgado-Povedano, M M; Calderón-Santiago, M; Luque de Castro, M D; Priego-Capote, F

    2018-01-15

    Sweat is a promising biofluid scarcely used in clinical analysis despite its non-invasive sampling. A more frequent clinical use of sweat requires to know its whole composition, especially concerning to non-polar compounds, and the development of analytical strategies for its characterization. The aim of the present study was to compare different sample preparation strategies to maximize the detection of metabolites in sweat from humans collected after practicing moderate exercise. Special emphasis was put on non-polar compounds as they have received scant attention in previous studies dealing with this biofluid. Sample preparation by liquid-liquid extraction (LLE) using extractants with different polarity index was compared to deproteination. Then, derivatization by methoxymation with subsequent silylation was compared to direct analysis of sweat extracts to check the influence of derivatization on the subsequent determination of volatile organic compounds (VOCs). 135 compounds were tentatively identified by combining spectral and retention time information after analysis by gas chromatography coupled to mass spectrometry in high resolution mode (GC-TOF/MS). Lipids, VOCs, benzenoids and other interesting metabolites such as alkaloids and ethanolamines were identified. Among the tested protocols, methyoxiamination plus silylation after LLE with dichloromethane was the best option to obtain a representative snapshot of sweat metabolome collected from different body parts after moderate exercise. Passive and active sweat pools from a cohort of volunteers (n = 6) were compared to detect compositional differences which can be explained by the sampling process and sweating induction. As most of the identified compounds are metabolites involved in key biochemical pathways, this study opens new opportunities to extend the applicability of human sweat as a source of metabolite biomarkers of pathologies or specific processes such as dehydration or nutritional unbalance

  12. Relationship between sweat chloride, sodium, and age in clinically obtained samples.

    Science.gov (United States)

    Traeger, Nadav; Shi, Qiuhu; Dozor, Allen J

    2014-01-01

    The relationship between sweat electrolytes and age is uncertain, as is the value of measuring sodium or the chloride:sodium ratio. 13,785 sweat tests performed over 23 years at one center through the Macroduct collection in clinically obtained samples were analyzed. Sweat chloride tended to decrease over the first year of life, slowly increase until the fourth decade, then either level off or slightly decrease. In children, sweat sodium overlapped between those with positive and negative sweat tests, but not in adults. If the sweat test was positive, there was a higher likelihood of having a chloride:sodium ratio >1, but most subjects with a ratio >1 did not have CF. Sweat chloride and sodium vary with age. Measurement of sweat sodium did not add discriminatory value. The proportion of subjects with a chloride:sodium ratio >1, with or without CF, varied greatly between age ranges. © 2013. Published by Elsevier B.V. on behalf of European Cystic Fibrosis Society. All rights reserved.

  13. Thin, Soft, Skin-Mounted Microfluidic Networks with Capillary Bursting Valves for Chrono-Sampling of Sweat.

    Science.gov (United States)

    Choi, Jungil; Kang, Daeshik; Han, Seungyong; Kim, Sung Bong; Rogers, John A

    2017-03-01

    Systems for time sequential capture of microliter volumes of sweat released from targeted regions of the skin offer the potential to enable analysis of temporal variations in electrolyte balance and biomarker concentration throughout a period of interest. Current methods that rely on absorbent pads taped to the skin do not offer the ease of use in sweat capture needed for quantitative tracking; emerging classes of electronic wearable sweat analysis systems do not directly manage sweat-induced fluid flows for sample isolation. Here, a thin, soft, "skin-like" microfluidic platform is introduced that bonds to the skin to allow for collection and storage of sweat in an interconnected set of microreservoirs. Pressure induced by the sweat glands drives flow through a network of microchannels that incorporates capillary bursting valves designed to open at different pressures, for the purpose of passively guiding sweat through the system in sequential fashion. A representative device recovers 1.8 µL volumes of sweat each from 0.8 min of sweating into a set of separate microreservoirs, collected from 0.03 cm 2 area of skin with approximately five glands, corresponding to a sweat rate of 0.60 µL min -1 per gland. Human studies demonstrate applications in the accurate chemical analysis of lactate, sodium, and potassium concentrations and their temporal variations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Nano-sponge ionic liquid-polymer composite electrolytes for solid-state lithium power sources

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Kang-Shyang; Andreoli, Enrico; Curran, Seamus A. [Department of Physics, University of Houston, Houston, TX 77004 (United States); Sutto, Thomas E. [Naval Research Labs-DC, Materials Science and Technology Division, Washington, DC 20375 (United States); Ajayan, Pulickel [Department of Materials Engineering, Rice University, Houston, TX 77005 (United States); McGrady, Karen A. [Marine Corps System Command, 50 Tech Parkway, Garrisonville, VA 22463 (United States)

    2010-02-01

    Solid polymer gel electrolytes composed of 75 wt.% of the ionic liquid, 1-n-butyl-2,3-dimethylimidazolium bis-trifluoromethanesulfonylimide with 1.0 M lithium bis-trifluoromethanesulfonylimide and 25 wt.% poly(vinylidenedifluoro-hexafluoropropene) are characterized as the electrolyte/separator in solid-state lithium batteries. The ionic conductivity of these gels ranges from 1.5 to 2.0 mS cm{sup -1}, which is several orders of magnitude more conductive than any of the more commonly used solid polymers, and comparable to the best solid gel electrolytes currently used in industry. TGA indicates that these polymer gel electrolytes are thermally stable to over 280 C, and do not begin to thermally decompose until over 300 C; exhibiting a significant advancement in the safety of lithium batteries. Atomic force microscopy images of these solid thin films indicate that these polymer gel electrolytes have the structure of nano-sponges, with a sub-micron pore size. For these thin film batteries, 150 charge-discharge cycles are run for Li{sub x}CoO{sub 2} where x is cycled between 0.95 down to 0.55. Minimal internal resistance effects are observed over the charging cycles, indicating the high ionic conductivity of the ionic liquid solid polymer gel electrolyte. The overall cell efficiency is approximately 98%, and no significant loss in battery efficiency is observed over the 150 cycles. (author)

  15. Effect of electrolyte composition and deposition current for Fe/Fe-P electroformed bilayers for biodegradable metallic medical applications.

    Science.gov (United States)

    Mostavan, Afghany; Paternoster, Carlo; Tolouei, Ranna; Ghali, Edward; Dubé, Dominique; Mantovani, Diego

    2017-01-01

    With its proven biocompatibility and excellent mechanical properties, iron is an excellent source material for clinical cardiac and vascular applications. However, its relatively low degradation rate limits its use for the healing and remodeling of diseased blood vessels. To address these issues, a multi-purpose fabrication process to develop a bilayer alloy composed of electroformed iron (E-Fe) and iron-phosphorus (Fe-P) was employed. Bilayers of Fe/Fe-P were produced in an electrolytic bath. The effects of electrolyte chemical composition and deposition current density (idep) on layer structure and chemical composition were assessed by scanning electron microscopy, electron probe microanalysis, X-ray diffraction and X-ray photoelectron spectroscopy. The corrosion rate was determined by potentiodynamic polarization tests. The bilayers showed an increasing amount of P with increasing NaH2PO4·H2O in the electrolyte. Fe-P structure became finer for higher P amounts. Potentiodynamic polarization tests revealed that the corrosion rate was strongly influenced by deposition conditions. For a P amount of ~2 wt.%, the corrosion rate was 1.46mm/year, which confirms the potential of this material to demonstrate high mechanical properties and a suitable corrosion rate for biomedical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. [The mineral composition of the carbohydrate-electrolyte drinks, vitamin-mineral complexes and dietary supplements for athletes].

    Science.gov (United States)

    Nikitiuk, D B; Novokshanova, A L; Abrosimova, S V; Gapparova, K M; Pozdniakov, A L

    2012-01-01

    In the article analyzes the macro- and trace element composition of sports drinks, vitamin-mineral complexes and biologically active additives (BAA). The estimation of the mineral collection of these products compared with the recommended standards. Established mineral composition many of the carbohydrate-electrolyte solutions, vitamin-mineral complexes and biologically active additives corresponds the physiology standards. However in some vitamin-mineral complexes and especially biologically active additives a number of minerals can be either unreasonably low or unreasonably high. Furthermore during labeling, mainly in the category D, a number of errors were revealed. Particularly there were lack of instructions about the number of declared ingredients, inaccuracies in the calculations of the daily requirement of mineral elements etc. Providing of an athlete organism with minerals should be carried out not only by carbohydrate-electrolyte solutions, vitamin-mineral complexes and specialized BAA, but mainly through basal ration. Utilising of carbohydrate-electrolyte solutions, vitamin-mineral complexes and biologically active additives can be justified only by the recommendations of experts. This is true not only in pro sports, but for the mass sports, as well as for individual physical training, in order to maintain physically fit.

  17. Sweat secretion rates in growth hormone disorders

    DEFF Research Database (Denmark)

    Sneppen, S B; Main, K M; Juul, A

    2000-01-01

    While increased sweating is a prominent symptom in patients with active acromegaly, reduced sweating is gaining status as part of the growth hormone deficiency (GHD) syndrome.......While increased sweating is a prominent symptom in patients with active acromegaly, reduced sweating is gaining status as part of the growth hormone deficiency (GHD) syndrome....

  18. Why Do I Sweat So Much?

    Science.gov (United States)

    ... Your Parents - or Other Adults Why Do I Sweat So Much? KidsHealth > For Teens > Why Do I Sweat So Much? Print A A A en español ¿Por qué sudo tanto? It's perfectly normal to sweat. Sweating plays an important health role because it ...

  19. A Newly Designed Composite Gel Polymer Electrolyte Based on Poly(Vinylidene Fluoride-Hexafluoropropylene) (PVDF-HFP) for Enhanced Solid-State Lithium-Sulfur Batteries.

    Science.gov (United States)

    Xia, Yan; Wang, Xiuli; Xia, Xinhui; Xu, Ruochen; Zhang, Shengzhao; Wu, Jianbo; Liang, Yanfei; Gu, Changdong; Tu, Jiangping

    2017-10-26

    Developing high-performance solid-state electrolytes is crucial for the innovation of next-generation lithium-sulfur batteries. Herein, a facile method for preparation of a novel gel polymer electrolyte (GPE) based on poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) is reported. Furthermore, Li1.5 Al0.5 Ti1.5 (PO4 )3 (LATP) nanoparticles as the active fillers are uniformly embedded into the GPE to form the final PVDF-HFP/LATP composite gel polymer electrolyte (CPE). Impressively, the obtained CPE demonstrates a high lithium ion transference number of 0.51 and improved electrochemical stability as compared to commercial liquid electrolyte. In addition, the assembled solid-sate Li-S battery with the composite gel polymer electrolyte membrane presents a high initial capacity of 918 mAh g-1 at 0.05 C, and better cycle performance than the counterparts with liquid electrolyte. Our designed PVDF-HFP/LATP composite can be a promising electrolyte for next-generation solid-state batteries with high cycling stability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Cross-linked Composite Gel Polymer Electrolyte using Mesoporous Methacrylate-Functionalized SiO2 Nanoparticles for Lithium-Ion Polymer Batteries.

    Science.gov (United States)

    Shin, Won-Kyung; Cho, Jinhyun; Kannan, Aravindaraj G; Lee, Yoon-Sung; Kim, Dong-Won

    2016-05-18

    Liquid electrolytes composed of lithium salt in a mixture of organic solvents have been widely used for lithium-ion batteries. However, the high flammability of the organic solvents can lead to thermal runaway and explosions if the system is accidentally subjected to a short circuit or experiences local overheating. In this work, a cross-linked composite gel polymer electrolyte was prepared and applied to lithium-ion polymer cells as a safer and more reliable electrolyte. Mesoporous SiO2 nanoparticles containing reactive methacrylate groups as cross-linking sites were synthesized and dispersed into the fibrous polyacrylonitrile membrane. They directly reacted with gel electrolyte precursors containing tri(ethylene glycol) diacrylate, resulting in the formation of a cross-linked composite gel polymer electrolyte with high ionic conductivity and favorable interfacial characteristics. The mesoporous SiO2 particles also served as HF scavengers to reduce the HF content in the electrolyte at high temperature. As a result, the cycling performance of the lithium-ion polymer cells with cross-linked composite gel polymer electrolytes employing methacrylate-functionalized mesoporous SiO2 nanoparticles was remarkably improved at elevated temperatures.

  1. Multidimensional Raman spectroscopic signature of sweat and its potential application to forensic body fluid identification.

    Science.gov (United States)

    Sikirzhytski, Vitali; Sikirzhytskaya, Aliaksandra; Lednev, Igor K

    2012-03-09

    This proof-of-concept study demonstrated the potential of Raman microspectroscopy for nondestructive identification of traces of sweat for forensic purposes. Advanced statistical analysis of Raman spectra revealed that dry sweat was intrinsically heterogeneous, and its biochemical composition varies significantly with the donor. As a result, no single Raman spectrum could adequately represent sweat traces. Instead, a multidimensional spectroscopic signature of sweat was built that allowed for the presentation of any single experimental spectrum as a linear combination of two fluorescent backgrounds and three Raman spectral components dominated by the contribution from lactate, lactic acid, urea and single amino acids. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Claudin-3 loss causes leakage of sweat from the sweat gland to contribute to the pathogenesis of atopic dermatitis.

    Science.gov (United States)

    Yamaga, Kosuke; Murota, Hiroyuki; Tamura, Atsushi; Miyata, Hirofumi; Ohmi, Masato; Kikuta, Junichi; Ishii, Masaru; Tsukita, Sachiko; Katayama, Ichiro

    2017-12-22

    The transfer of sweat to the skin surface without leakage is important for the homeostatic regulation of skin and is impaired in atopic dermatitis (AD). Although the precise composition of the leakage barrier remains obscure, there is a large contribution from claudins, the major components of tight junctions. In humans, claudin-1, -3, and -15 are expressed on sweat ducts, and claudin-3 and -10 are expressed on secretory coils. Although only two claudins are expressed in murine sweat glands, we found that the expression of claudin-3 is conserved. AD lesional skin had decreased claudin-3 expression in sweat glands, which was accompanied by sweat leakage. This critical role in water barrier function was confirmed in Cldn3 -/- and Cldn3 +/- mice and those with experimentally decreased claudin-3. Our results reveal the crucial role of claudin-3 in preventing sweat gland leakage and suggest that the pathogenesis of dermatoses accompanied by hypohidrosis involves abnormally decreased claudin-3. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Characterization of sweat induced with pilocarpine, physical exercise, and collected passively by metabolomic analysis.

    Science.gov (United States)

    Souza, S L; Graça, G; Oliva, A

    2017-11-12

    The elimination of the pain associated with needle picking is a strong motivation for the development of clinical non-invasive diagnostic methods. Sweat has been described as an alternative biological sample that may have a direct relation to the plasma composition. In this study, analysis of sweat of human volunteers obtained by induction with pilocarpine is compared with sweat samples obtained by physical exercise and by passive collection along 7 hours. The sweat samples have been analyzed by 1H nuclear magnetic resonance spectroscopy. A range of 34 different metabolites has been detected in sweat samples, including lactate, several amino acids, pyroglutamate, and urocanate. Most of the metabolites identified were quantified. The majority of the amino acids detected in sweat seem to have origin in the epidermis surface. No significant differences in sweat samples from female and male were observed by 1H NMR metabolomic analysis. Principal component analysis (PCA) shows that both physical exercise and pilocarpine methods seem to be equally reproducible methods in terms of sweat metabolite composition presenting better repeatability than natural sweat collection. Nevertheless, this difference is mainly originated from amino acids with origin from the skin surface. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Estradiol rapidly induces the translocation and activation of the intermediate conductance calcium activated potassium channel in human eccrine sweat gland cells.

    LENUS (Irish Health Repository)

    Muchekehu, Ruth W

    2009-02-01

    Steroid hormones target K+ channels as a means of regulating electrolyte and fluid transport. In this study, ion transporter targets of Estradiol (E2) were investigated in the human eccrine sweat gland cell line NCL-SG3.

  5. The reproducibility of closed-pouch sweat collection and thermoregulatory responses to exercise-heat stress.

    Science.gov (United States)

    Hayden, Gavin; Milne, Helen C; Patterson, Mark J; Nimmo, Myra A

    2004-05-01

    Seven active male subjects cycled for 60 min at 29.5 (0.8)% peak work rate on three separate occasions in a hot environmental condition [36.0 (0.1) degrees C, 60 (1)% relative humidity] in order to determine the reproducibility of a closed-pouch sweat collection technique for sweat composition at the scapula, forearm and thigh. To confirm that sweat composition was not influenced by between-trial variations in sudomotor drive, local sweat rate, whole-body sweat rate, heart rate (HR), rectal temperature (T(re)) and mean skin temperature (T(sk)) responses were also measured, consequently reproducibility was also established for these variables. Sweat composition did not differ among trials, with the mean coefficients of variation (CVs) for sweat [Na(+)], [K(+)] and pH being 10.4 (7.4)%, 8.1 (6.5)% and 1.3 (1.1)%, respectively. Local sweat rates did not differ among the three trials (P>0.05) although whole-body sweat rate was reduced in the third trial (Psweat rates, respectively. Between-trial differences were not evident for T(re), T(sk) or HR with mean CVs of 0.3 (0.2)%, 0.7 (0.6)% and 3.9 (1.7)%, respectively, although HR tended to be greater in the first trial ( P=0.08). It is proposed that moderate variations in sweat composition were influenced by variations in the local sweat rate, which were induced by application of the pouch.

  6. Micromold methods for fabricating perforated substrates and for preparing solid polymer electrolyte composite membranes

    Energy Technology Data Exchange (ETDEWEB)

    Mittelsteadt, Cortney; Argun, Avni; Laicer, Castro; Willey, Jason

    2017-08-08

    In polymer electrolyte membrane (PEM) fuel cells and electrolyzes, attaining and maintaining high membrane conductivity and durability is crucial for performance and efficiency. The use of low equivalent weight (EW) perfluorinated ionomers is one of the few options available to improve membrane conductivity. However, excessive dimensional changes of low EW ionomers upon application of wet/dry or freeze/thaw cycles yield catastrophic losses in membrane integrity. Incorporation of ionomers within porous, dimensionally-stable perforated polymer electrolyte membrane substrates provides improved PEM performance and longevity. The present invention provides novel methods using micromolds to fabricate the perforated polymer electrolyte membrane substrates. These novel methods using micromolds create uniform and well-defined pore structures. In addition, these novel methods using micromolds described herein may be used in batch or continuous processing.

  7. Composite Electrolytes for Lithium Batteries: Ionic Liquids in APTES Crosslinked Polymers

    Science.gov (United States)

    Tigelaar, Dean M.; Meador, Mary Ann B.; Bennett, William R.

    2007-01-01

    Solvent free polymer electrolytes were made consisting of Li(+) and pyrrolidinium salts of trifluoromethanesulfonimide added to a series of hyperbranched poly(ethylene oxide)s (PEO). The polymers were connected by triazine linkages and crosslinked by a sol-gel process to provide mechanical strength. The connecting PEO groups were varied to help understand the effects of polymer structure on electrolyte conductivity in the presence of ionic liquids. Polymers were also made that contain poly(dimethylsiloxane) groups, which provide increased flexibility without interacting with lithium ions. When large amounts of ionic liquid are added, there is little dependence of conductivity on the polymer structure. However, when smaller amounts of ionic liquid are added, the inherent conductivity of the polymer becomes a factor. These electrolytes are more conductive than those made with high molecular weight PEO imbibed with ionic liquids at ambient temperatures, due to the amorphous nature of the polymer.

  8. In situ Poly(methyl methacrylate)/Graphene Composite Gel Electrolytes for Highly Stable Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Kang, Yu-il; Moon, Jun Hyuk

    2015-11-01

    Dye-sensitized solar cells (DSCs) with long-term stability are produced using polymer-gel electrolytes (PGEs). In this study, we introduce the formation of PGEs using in situ gelation with poly(methyl methacrylate) (PMMA) particles and graphene fillers that are pre-deposited on the counter electrodes. We obtain a high concentration PMMA-based PGEs (i.e., over 10 wt%). A DSC composed of a PMMA/graphene composite PGEs exhibits an 8.49% photon-to-electric conversion efficiency, which is comparable to conventional liquid electrolyte DSCs. This finding is attributed to increased ion diffusivity and conductivity of the PMMA-based PGEs resulting from the incorporation of graphene nanofillers. The PMMA-based PGE DSCs exhibit highly stable long-term efficiencies, maintaining up to 90% of their initial efficiency during thermal soaking, whereas the efficiencies of liquid electrolyte cells decrease significantly, by up to 60%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Enhancing long-term photostability of BiVO4 photoanodes for solar water splitting by tuning electrolyte composition

    Science.gov (United States)

    Lee, Dong Ki; Choi, Kyoung-Shin

    2018-01-01

    As the performance of photoelectrodes used for solar water splitting continues to improve, enhancing the long-term stability of the photoelectrodes becomes an increasingly crucial issue. In this study, we report that tuning the composition of the electrolyte can be used as a strategy to suppress photocorrosion during solar water splitting. Anodic photocorrosion of BiVO4 photoanodes involves the loss of V5+ from the BiVO4 lattice by dissolution. We demonstrate that the use of a V5+-saturated electrolyte, which inhibits the photooxidation-coupled dissolution of BiVO4, can serve as a simple yet effective method to suppress anodic photocorrosion of BiVO4. The V5+ species in the solution can also incorporate into the FeOOH/NiOOH oxygen-evolution catalyst layer present on the BiVO4 surface during water oxidation, further enhancing water-oxidation kinetics. The effect of the V5+ species in the electrolyte on both the long-term photostability of BiVO4 and the performance of the FeOOH/NiOOH oxygen-evolution catalyst layer is systematically elucidated.

  10. Interfacial Characteristics and Fracture Toughness of Electrolytically Ni-Plated Carbon Fiber-Reinforced Phenolic Resin Matrix Composites.

    Science.gov (United States)

    Park, Soo-Jin; Jang, Yu-Sin

    2001-05-01

    The electrolytic plating of metallic nickel on a carbon fiber surface has been carried out in order to improve the interfacial adhesion and the mechanical properties in carbon fiber/phenolic matrix composite systems. The surface and the mechanical interfacial properties of composites are characterized by X-ray photoelectron spectrometry (XPS), surface free energy, and the critical stress intensity factor (K(IC)). From the experimental results, it is clearly revealed that the oxygen functional groups and the metallic nickel on fibers largely affect the mechanical interfacial behavior of the composites, resulting in increased surface polarity, whereas the nitrogen functional groups have no effect. Also, a good correlation between surface oxygen functional groups and mechanical interfacial properties and between wettability and K(IC) is established and it is found that a 10 A m(-2) current density is the optimum condition for this system. Copyright 2001 Academic Press.

  11. Highly conductive quasi-coaxial electrospun quaternized polyvinyl alcohol nanofibers and composite as high-performance solid electrolytes

    Science.gov (United States)

    Liao, Guan-Ming; Li, Pin-Chieh; Lin, Jia-Shiun; Ma, Wei-Ting; Yu, Bor-Chern; Li, Hsieh-Yu; Liu, Ying-Ling; Yang, Chun-Chen; Shih, Chao-Ming; Lue, Shingjiang Jessie

    2016-02-01

    Electrospun quaternized polyvinyl alcohol (Q-PVA) nanofibers are prepared, and a potassium hydroxide (KOH)-doped nanofiber mat demonstrates enhanced ionic conductivity compared with a dense Q-PVA film with KOH doping. The Q-PVA composite containing 5.98% electrospun Q-PVA nanofibers exhibits suppressed methanol permeability. Both the high conductivity and suppressed methanol permeability are attributed to the quasi-coaxial structure of the electrospun nanofibers. The core of the fibers exhibits a more amorphous region that forms highly conductive paths, while the outer shell of the nanofibers contains more polymer crystals that serve as a hard sheath surrounding the soft core. This shell induces mass transfer resistance and creates a tortuous fuel pathway that suppresses methanol permeation. Such a Q-PVA composite is an effective solid electrolyte that makes the use of alkaline fuel cells viable. In a direct methanol alkaline fuel cell operated at 60 °C, a peak power density of 54 mW cm-2 is obtained using the electrospun Q-PVA composite, a 36.4% increase compared with a cell employing a pristine Q-PVA film. These results demonstrate that highly conductive coaxial electrospun nanofibers can be prepared through a single-opening spinneret and provide a possible approach for high-performance electrolyte fabrication.

  12. Enabling electrolyte compositions for columnar silicon anodes in high energy secondary batteries

    Science.gov (United States)

    Piwko, Markus; Thieme, Sören; Weller, Christine; Althues, Holger; Kaskel, Stefan

    2017-09-01

    Columnar silicon structures are proven as high performance anodes for high energy batteries paired with low (sulfur) or high (nickel-cobalt-aluminum oxide, NCA) voltage cathodes. The introduction of a fluorinated ether/sulfolane solvent mixture drastically improves the capacity retention for both battery types due to an improved solid electrolyte interface (SEI) on the surface of the silicon electrode which reduces irreversible reactions normally causing lithium loss and rapid capacity fading. For the lithium silicide/sulfur battery cycling stability is significantly improved as compared to a frequently used reference electrolyte (DME/DOL) reaching a constant coulombic efficiency (CE) as high as 98%. For the silicon/NCA battery with higher voltage, the addition of only small amounts of fluoroethylene carbonate (FEC) to the novel electrolyte leads to a stable capacity over at least 50 cycles and a CE as high as 99.9%. A high volumetric energy density close to 1000 Wh l-1 was achieved with the new electrolyte taking all inactive components of the stack into account for the estimation.

  13. Sweat: a sample with limited present applications and promising future in metabolomics.

    Science.gov (United States)

    Mena-Bravo, A; Luque de Castro, M D

    2014-03-01

    Sweat is a biofluid with present scant use as clinical sample. This review tries to demonstrate the advantages of sweat over other biofluids such as blood or urine for routine clinical analyses and the potential when related to metabolomics. With this aim, critical discussion of sweat samplers and equipment for analysis of target compounds in this sample is made. Well established routine analyses in sweat as is that to diagnose cystic fibrosis, and the advantages and disadvantages of sweat versus urine or blood for doping control have also been discussed. Methods for analytes such as essential metals and xenometals, ethanol and electrolytes in sweat in fact constitute target metabolomics approaches or belong to any metabolomics subdiscipline such as metallomics, ionomics or xenometabolomics. The higher development of biomarkers based on genomics or proteomics as omics older than metabolomics is discussed and also the potential role of metabolomics in systems biology taking into account its emergent implementation. Normalization of the volume of sampled sweat constitutes a present unsolved shortcoming that deserves investigation. Foreseeable trends in this area are outlined. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Synthesis and Characterization of La, Sc, Yb and Nd co-doped Gadolinium doped Cerium (GDC) Composite Electrolyte for IT-SOFC

    Science.gov (United States)

    Damisih; Raharjo, Jarot; Masmui; Setya Aninda, Raffty; Ami Lestari, Novita

    2017-07-01

    Composite based on gadolinium doped cerium (GDC) co-doped Lanthanum (La), Scandium (Sc), Ytterbium (Yb) were investigated as electrolyte for solid oxide fuel cell (SOFC), namely GDC-La, GDC-Sc, GDC-Yb and GDC-Nd, respectively. The second co-doped La, Sc, Yb and Nd ensured the stability and high ionic conductivity of the GDC ceria-based electrolyte materials for SOFC. The GDC powder was synthesized via sol-gel technique. Then the La-GDC, Sc-GDC, Yb-GDC and GDC-Nd were subsequently prepared by mixing the GDC with La, Sc, Yb, and Nd respectively, through solid-state reaction in ballmill at 200rpm alumina balls. The composite electrolytes were then characterized in terms of its morphology, phase and thermal properties of the powders. Among the composite electrolytes investigated, GDC-Yb powder show higher purity and better dispersion than the others co-doped GDC. TGA analysis present that the addition of co-dopant led to improve thermal resistance and stability of solid electrolyte powders. The results confirm that GDC with co-dopant is promising alternative electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFC).

  15. Composite electrolytes of polyethylene glycol methyl ether and TiO{sub 2} for dye-sensitized solar cells-Effect of heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, M. Shaheer, E-mail: shaheerakhtar@jbnu.ac.kr [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); New and Renewable Energy Material Development Center (NewREC), Chonbuk National University (Korea, Republic of); Park, Jung-Guen; Kim, Ui-Yeon [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Yang, O-Bong, E-mail: obyang@jbnu.ac.kr [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); New and Renewable Energy Material Development Center (NewREC), Chonbuk National University (Korea, Republic of)

    2011-06-15

    Highlights: {yields} The heat treatment (80 deg. C) on prepared PEGME-TiO{sub 2} composite was essential step to improve the morphological and electrochemical properties. {yields} Raman spectra of PEGME-acid, PEGME-TiO{sub 2} and PEGME-TiO{sub 2}/80 deg. C composite electrolytes. {yields} PEGME-TiO{sub 2}/80 deg. C shows drastically increased strong peak (I{sub 3}{sup -} species) with a slight shifting at 113.1 cm{sup -1}. {yields} Indicates the significant increase of I{sub 3}{sup -} species in redox electrolytes upon heat treatment. - Abstract: For solid-state dye-sensitized solar cells (DSSCs), a composite electrolyte of polyethylene glycol methyl ether (PEGME) and titania (TiO{sub 2}) nanoparticles was prepared and characterized by Fourier transform-infra red (FT-IR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Raman spectroscopy. The heat treatment on PEGME and TiO{sub 2} composite was found to be an essential step to improve morphology, amorphicity and ionic conductivity of PEGME-TiO{sub 2} composite electrolytes. It was attributed to the increased bond strength of OC-O-Ti between PEGME and TiO{sub 2} and increased surface roughness of composite materials, which may help to absorb a large amount of iodide couple and effective generation of I{sub 3}{sup -} ions. A DSSC fabricated with heat treated PEGME-TiO{sub 2} composite electrolyte showed significantly enhanced overall conversion efficiency of 3.1%, which was 20% higher than that of the DSSC fabricated with bare PEGME-TiO{sub 2} composite electrolyte.

  16. Comparison of three methods for estimation of exercise-related ion losses in sweat of horses.

    Science.gov (United States)

    Kingston, J K; McCutcheon, L J; Geor, R J

    1999-10-01

    To quantify total fluid loss in sweat of Thoroughbreds during >3 hours of low-intensity exercise in controlled conditions and to calculate and compare estimated ion losses in sweat, according to 3 methods. 6 exercise-trained Thoroughbreds. Fluid and ion losses in sweat were measured in 6 horses exercising at 40% of the speed that elicited maximum oxygen consumption for 45 km. Horses were given a 15-minute rest period at the end of three 15-km exercise phases. Horses completed 2 exercise trials. Ion losses in sweat were calculated, using measurements of local sweating rate and sweat ion composition (SWT), change in net exchangeable cation content (CAT), and change in extracellular ion content (PLAS) derived from plasma total solids and ion concentrations. Measurement of SWT revealed a mean (+/- SEM) fluid loss in sweat during 45 km of exercise of 27.5 +/- 1.6 L. Total ion loss in sweat was approximately 241 g or 7.8 mol with higher sodium losses in the second and third phases of exercise compared with the first phase. Losses of sodium and potassium calculated by SWT or CAT were not significantly different from each other, whereas losses of these ions as determined by PLAS were significantly lower. Calculation of ion losses from a mean whole body sweating rate extrapolated from either local sweating rate and sweat ion composition or from change in net exchangeable cation content provide similar results, whereas ion losses determined by changes in extracellular ion content derived from plasma total solids and ion concentration results in underestimation of actual losses.

  17. Final Report for Project DE-FG02-05ER15718 Fluoropolymers, Electrolytes, Composites and Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Creager, Stephen [Clemson Univ., SC (United States)

    2017-05-24

    This report is for a project that was initiated under the title “New Proton-Conducting Fluoropolymer Electrolytes for PEM Fuel Cells”, as part of the DOE program titled “Basic Research for the Hydrogen Fuel Cell Initiative”, Program Notice DE-FG01-04ER04-20. The project received 750,000 dollars in initial funding for a three-year term with a start date of August 15, 2005. Creager was PI and co-PIs were DesMarteau and Smith, all from Clemson. The project was renewed for a second three-year term with a start date of June 15 2008, again for 750,000 dollars, with the new title, “Fluoropolymers, Electrolytes, Composites and Electrodes”. Shortly after the renewal was put in place, co-PI Smith left Clemson to accept a position at the University of Texas at Dallas. After a period of no-cost extension the project was renewed on January 1 2013 for another three-year term, this time for a smaller amount ($525,000) and with Thrasher, a new senior hire at Clemson, as co-PI in place of Smith. DesMarteau had retired from Clemson by this time but was retained as a project advisor. After a final one-year no-cost extension for calendar year 2016, the project ended on December 31, 2016, giving it an active period of eleven and one-half years, from August 15 2005 to December 31 2016. The overall objective of this research project has been to create and understand the behavior of new fluoropolymer-based electrolytes and electrodes suitable for use in electrochemical energy storage and conversion devices. The objective was pursued via research on new fluorinated monomers, new polymers and polyelectrolytes (also known as ionomers), and new electrocatalyst supports that in some cases include chemically grafted electrolytes to promote rapid ion transport to electrocatalytically active sites (usually platinum nanoparticles) on the support. The research involved synthesis and characterization of new materials, and creation and use of new measurement techniques that address key

  18. Composite polymer electrolytes for fuel cell applications: filler-induced effect on water sorption and transport properties.

    Science.gov (United States)

    Mecheri, Barbara; Felice, Valeria; D'Epifanio, Alessandra; Tavares, Ana C; Licoccia, Silvia

    2013-11-11

    Nafion- and sulfonated polysulfone (SPS)- based composite membranes were prepared by incorporation of SnO2 nanoparticles in a wide range of loading (0${ \\div }$35 wt. %). The composites were investigated by differential scanning calorimetry, dynamic vapor sorption and electrochemical impedance spectroscopy to study the filler effect on water sorption, water mobility, and proton conductivity. A detrimental effect of the filler was observed on water mobility and proton conductivity of Nafion-based membranes. An increase in water mobility and proton conductivity was instead observed in SPS-based samples, particularly at low hydration degree. Analysis of the water sorption isotherms and states of water revealed that the presence of SnO2 in SPS enhances interconnectivity of hydrophilic domains, while not affecting the Nafion microstructure. These results enable the design of suitable electrolyte materials that operate in proton exchange membrane fuel cell conditions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Behavioural responses of Anopheles gambiae sensu stricto to components of human breath, sweat and urine depend on mixture composition and concentration.

    Science.gov (United States)

    Qiu, Y T; Smallegange, R C; VAN Loon, J J A; Takken, W

    2011-09-01

    Host-seeking behaviour of the anthropophilic malaria vector Anopheles gambiae sensu stricto (Diptera: Culicidae) is mediated predominantly by olfactory cues. Several hundreds of odour components have been identified from human emanations, but only a few have been proven to act as attractants or synergists in the host-seeking behaviour of female An. gambiae. In previous work, aromatics, alcohols and ketones in human odours were found to elicit electrophysiological activity in antennal olfactory neurons of female An. gambiae. However, the behavioural effects of these compounds have not been investigated. In this study, behavioural responses of female An. gambiae to components of human breath, urine and sweat at a series of concentrations, or a single concentration in the case of acetone, were examined in combination with ammonia and L-lactic acid in a dual-choice olfactometer. The results showed that at specific concentrations 4-ethylphenol, indole, 3-methyl-1-butanol and two ketones inhibited the attractive effect of a mixture of ammonia and lactic acid. Acetone on its own was not attractive; however, when combined with lactic acid, the binary mixture was attractive. When combined with ammonia, acetone inhibited the attractiveness exerted by ammonia alone. Dodecanol and dimethyldisulphide did not affect the attraction exerted by ammonia and lactic acid at any of the concentrations tested. By contrast, a human-specific armpit odour, 7-octenoic acid, augmented the attraction exerted by the combination of ammonia and lactic acid at a specific dosage. © 2010 The Authors. Medical and Veterinary Entomology © 2010 The Royal Entomological Society.

  20. The role of cathodic current in PEO of aluminum: Influence of cationic electrolyte composition on the transient current-voltage curves and the discharges optical emission spectra

    Science.gov (United States)

    Rogov, A. B.; Shayapov, V. R.

    2017-02-01

    In this paper, the influence of cationic electrolytes composition on electrical and optical responses of plasma electrolytic oxidation process of A1050 aluminum alloy under alternating polarization is considered. The electrolytes consist of 0.1 M boric acid with addition of one of the following hydroxides: LiOH, NaOH, KOH, tetraethylammonium hydroxide, Ca(OH)2 up to pH value 9.2. Coatings microstructure, elemental and phase compositions were studied by SEM, EDS and XRD. It was shown that the hysteresis of anodic current-voltage curve (specific feature of "Soft sparking" PEO) was clear observed in the presence of sodium and potassium cations. It was found that composition of microdischarges plasma is also affected by the nature of the cations. It was shown that there are a number of reciprocal processes, which take place under anodic and cathodic polarization.

  1. Hydration and sweating responses to hot-weather football competition.

    Science.gov (United States)

    Kurdak, S S; Shirreffs, S M; Maughan, R J; Ozgünen, K T; Zeren, C; Korkmaz, S; Yazici, Z; Ersöz, G; Binnet, M S; Dvorak, J

    2010-10-01

    During a football match played in warm (34.3 ± 0.6 °C), humid (64 ± 2% rh) conditions, 22 male players had their pre-match hydration status, body mass change, sweat loss and drinking behavior assessed. Pre-match urine specific gravity (1.012 ± 0.006) suggested that all but three players commenced the match euhydrated. Players lost 3.1 ± 0.6 L of sweat and 45 ± 9 mmol of sodium during the 90-min match and replaced 55 ± 19% of their sweat losses and hence by the end of the game were 2.2 ± 0.9% lighter. The water volume consumed during the game was highly variable (1653 ± 487 mL; 741-2387 mL) but there was a stronger relationship between the estimated pre-game hydration status and water volume consumed, than between sweat rate and water volume consumed. In a second match, with the same players 2 weeks later in 34.4 ± 0.6 °C, 65 ± 3% rh, 11 players had a sports drink available to them before and during the match in addition to water. Total drink volume consumed during the match was the same, but approximately half the volume was consumed as sports drink. The results indicate that substantial sweat water and electrolyte losses can occur during match play in hot conditions and a substantial water and sodium deficit can occur in many players even when water or sports drink is freely available. © 2010 John Wiley & Sons A/S.

  2. High Specific Capacitance of Polyaniline/Mesoporous Manganese Dioxide Composite Using KI-H2SO4 Electrolyte

    Directory of Open Access Journals (Sweden)

    Zhongkai Hu

    2015-09-01

    Full Text Available The PANI/Mesoporous MnO2 composites were prepared through a simple one step method and we introduced the KI-H2SO4 solution as the electrolyte of PANI/MnO2 composites creatively. The characterization of structure, morphology, and composition are obtained by X-ray diffraction, Fourier transform infrared spectroscopy, thermal gravity analysis, Raman spectra, and scanning electron microscope. The electrochemical performances were investigated by constant-current charge–discharge, the voltammetry curve, and alternating current (AC impedance technique. The specific capacitance of composites is 1405 F/g, which is almost 10 times larger than MnO2 (158 F/g. We also find that the iodide concentration is closely related to the specific capacitance. Therefore, we explored the specific capacitance at different iodide concentration (0.05, 0.1, 0.2, 0.5, and 1 M, the results indicated that the specific capacitance reached a maximum value (1580 F/g at 0.5 mol/L. Additionally, the PANI/Mesoporous MnO2 composites not only exhibited a good ratio discharge property (857 F/g at high current density, but also revealed an excellent cycling stability after 500 cycles, which retained 90% of the original specific capacitance.

  3. Charge-discharge characteristics of LiCoO 2/mesocarbon microbeads battery with poly(vinyl chloride)-based composite polymer electrolyte

    Science.gov (United States)

    Subban, R. H. Y.; Arof, A. K.

    Polyvinyl chloride (PVC)-based composite polymer electrolyte films consisting of PVC-LiCF 3SO 3-SiO 2 are prepared by the solution-casting method. The electrical properties of the electrolyte are investigated for ionic conductivity and its dependence on temperature. The electrolyte with the highest ionic conductivity is used to fabricate a LiCoO 2/PVC-LiCF 3SO 3-SiO 2/mesocarbon microbeads (MCMB) battery. The charge-discharge characteristics and performance of the battery at room temperature are evaluated to ascertain the effective viability, of these solid electrolytes in lithium-polymer batteries. Battery performances is also investigated at 313, 323 and 333 K.

  4. Bioanalytical devices: Technological leap for sweat sensing

    Science.gov (United States)

    Heikenfeld, Jason

    2016-01-01

    Sweat analysis is an ideal method for continuously tracking a person's physiological state, but developing devices for this is difficult. A wearable sweat monitor that measures several biomarkers is a breakthrough. See Letter p.509

  5. Proteomic and peptidomic analysis of human sweat with emphasis on proteolysis.

    Science.gov (United States)

    Yu, Yijing; Prassas, Ioannis; Muytjens, Carla M J; Diamandis, Eleftherios P

    2017-02-23

    Sweat is produced by eccrine and apocrine glands and represents a biological fluid with established roles in thermo-regulation and host infection defense. The composition of sweat is highly dynamic and alters significantly in various skin and other disorders. Therefore, in-depth profiling of sweat protein composition is expected to augment our understanding of the pathobiology of several skin diseases and may lead to the identification of useful sweat-based disease biomarkers. We here reported an in-depth analysis of the human sweat proteome and peptidome. Sweat was collected from healthy males and healthy females of ages 20-60years, following strenuous exercise. Two sweat pools were prepared (1 for males and 1 for females) and were subjected to sample preparation for mass spectrometric analysis. We identified a total of 861 unique proteins during our proteomic analysis and 32,818 endogenous peptides (corresponding to additional 1067 proteins) from our peptidomics workflow. As expected, the human skin was identified as the most abundant source of sweat proteins and peptides. Several skin proteases and protease inhibitors were identified in human sweat, highlighting the intense proteolytic activity of human skin. The presence of several antimicrobial peptides supports the functional roles of sweat in host defense and innate immunity. Sweat is a skin-associated biological fluid, secreted by eccrine and apocrine glands, with essential function in body thermo-regulation and host infection defense. In the present study, we performed in-depth profiling of both sweat proteome and peptidome composition. Our data provide the most in-depth characterization of the skin's catalytic network present in sweat. For the first time, we brought to light novel peptides in human sweat that potentially have antimicrobial activity, which highlight the important role of this fluid in innate immunity. All these findings allow us to have a better understanding of the complex web of

  6. Sweat Therapy Theory, Practice, and Efficacy

    Science.gov (United States)

    Eason, Allen; Colmant, Stephen; Winterowd, Carrie

    2009-01-01

    The purpose of this article is to examine the potential application of sweat rituals to group counseling, adventure therapy, and other forms of group work by describing a theoretical model for how sweat rituals work and presenting the results of a randomized comparative outcome study on the efficacy of sweat therapy. The theoretical model proposes…

  7. A direct borohydride fuel cell based on poly(vinyl alcohol)/hydroxyapatite composite polymer electrolyte membrane

    Science.gov (United States)

    Yang, Chun-Chen; Li, Yingjeng James; Chiu, Shwu-Jer; Lee, Kuo-Tong; Chien, Wen-Chen; Huang, Ching-An

    A new poly(vinyl alcohol)/hydroxyapatite (PVA/HAP) composite polymer membrane was synthesized using a solution casting method. Alkaline direct borohydride fuel cells (DBFCs), consisting of an air cathode based on MnO 2/C inks on Ni-foam, anodes based on PtRu black and Au catalysts on Ni-foam, and the PVA/HAP composite polymer membrane, were assembled and investigated for the first time. It was demonstrated that the alkaline direct borohydride fuel cell comprised of this low-cost PVA/HAP composite polymer membrane showed good electrochemical performance. As a result, the maximum power density of the alkaline DBFC based on the PtRu anode (45 mW cm -2) proved higher than that of the DBFC based on the Au anode (33 mW cm -2) in a 4 M KOH + 1 M KBH 4 solution at ambient conditions. This novel PVA/HAP composite polymer electrolyte membrane with high ionic conductivity at the order of 10 -2 S cm -1 has great potential for alkaline DBFC applications.

  8. ZnTe Semiconductor-Polymer Gel Composited Electrolyte for Conversion of Solar Energy

    Directory of Open Access Journals (Sweden)

    Wonchai Promnopas

    2014-01-01

    Full Text Available Nanostructured cubic p-type ZnTe for dye sensitized solar cells (DSSCs was synthesized from 1 : 1 molar ratio of Zn : Te by 600 W and 900 W microwave plasma for 30 min. In this research, their green emissions were detected at the same wavelengths of 563 nm, the energy gap (Eg at 2.24 eV, and three Raman shifts at 205, 410, and 620 cm−1. The nanocomposited electrolyte of quasisolid state ZnO-DSSCs was in correlation with the increase in the JSC, VOC, fill factor (ff, and efficiency (η by increasing the wt% of ZnTe-GPE (gel polymer electrolyte to an optimum value and decreased afterwards. The optimal ZnO-DSSC performance was achieved for 0.20 wt% ZnTe-GPE with the highest photoelectronic energy conversion efficiency at 174.7% with respect to that of the GPE without doping of p-type ZnTe.

  9. Water and Electrolyte Needs for Football Training and Match-Play

    Science.gov (United States)

    2006-07-01

    The high metabolic rates sustained by soccer players during training and match- play cause sweat to be produced in both warm and temperate...sweat and electrolyte losses of players in the same training session or match dictates that individual monitoring to determine individual water and

  10. Do elephants need to sweat?

    African Journals Online (AJOL)

    higher increase (Clifford, Kerslake & Waddell 1959). Thus a number of factors studied under laboratory condi- tions in non-sweating human skin are pertinenl to this con- sideration of evaporative waler loss froro elephant skin and we have shown that the evaporative loss could provide the heat transfer necessary for thermal ...

  11. Normative data on regional sweat-sodium concentrations of professional male team-sport athletes.

    Science.gov (United States)

    Ranchordas, Mayur K; Tiller, Nicholas B; Ramchandani, Girish; Jutley, Raj; Blow, Andrew; Tye, Jonny; Drury, Ben

    2017-01-01

    The purpose of this paper was to report normative data on regional sweat sweat-sodium concentrations of various professional male team-sport athletes, and to compare sweat-sodium concentrations among sports. Data to this effect would inform our understanding of athlete sodium requirements, thus allowing for the individualisation of sodium replacement strategies. Accordingly, data from 696 athletes (Soccer, n = 270; Rugby, n = 181; Baseball, n = 133; American Football, n = 60; Basketball, n = 52) were compiled for a retrospective analysis. Regional sweat-sodium concentrations were collected using the pilocarpine iontophoresis method, and compared to self-reported measures collected via questionnaire. Sweat-sodium concentrations were significantly higher (p sports. There were strong positive correlations between sweat-sodium concentrations and self-reported sodium losses in American football (rs = 0.962, p sports science/medicine practitioners in generating bespoke hydration and electrolyte-replacement strategies to meet the sodium demands of professional team-sport athletes. Moreover, these novel data suggest that self-reported measures of sodium loss might serve as an effective surrogate in the absence of direct measures; i.e., those which are more expensive or non-readily available.

  12. Branched Rod-Coil Polyimide-Poly(Alkylene Oxide) Copolymers and Electrolyte Compositions

    Science.gov (United States)

    Meador, Maryann B. (Inventor); Tigelaar, Dean M. (Inventor)

    2014-01-01

    Crosslinked polyimide-poly(alkylene oxide) copolymers capable of holding large volumes of liquid while maintaining good dimensional stability. Copolymers are derived at ambient temperatures from amine endcapped amic-acid oligomers subsequently imidized in solution at increased temperatures, followed by reaction with trifunctional compounds in the presence of various additives. Films of these copolymers hold over four times their weight at room temperature of liquids such as ionic liquids (RTIL) and/or carbonate solvents. These rod-coil polyimide copolymers are used to prepare polymeric electrolytes by adding to the copolymers various amounts of compounds such as ionic liquids (RTIL), lithium trifluoromethane-sulfonimide (LiTFSi) or other lithium salts, and alumina.

  13. Rehydration and catabolic preventive effects depend on the composition of oral electrolyte solutions for diarrheic calves.

    Science.gov (United States)

    Tsukano, Kenji; Ajito, Tadaharu; Abe, Izumi; Sarashina, Shinya; Suzuki, Kazuyuki

    2017-11-10

    In this study, two commercially available oral electrolyte solutions (OES) with high sodium (CF) or with high glucose and glycine (SL), and two prototype OES were evaluated in terms of rehydration and preventing catabolism. Prototype OES based on CF were prepared by doubling the glucose amount (CFG) or by doubling both glucose and glycine (CFGG). Thirty-two diarrheic calves were randomly assigned four groups with eight calves in each group. Blood volume increased with CF and CFGG compared with that of other OES. The catabolic preventive effect was excellent in CFGG and SL. Our results suggest that both the amount of sodium, glucose, and glycine, and ratio of these factors aid dehydration and provide energy.

  14. Computer optimization of background electrolyte composition in the separation of metal ions by capillary electrophoresis.

    Science.gov (United States)

    Billiet, H A; Andersson, P E; Haddad, P R

    1996-08-01

    The iterative regression design developed earlier for high performance liquid chromatography (HPLC) has been applied successfully to the optimization of the separation of 11 metal ions by capillary electrophoresis. The parameters used for optimization were pH (over the range 3.5-5.0) and the concentration of 2-hydroxyisobutyric acid (HIBA) (2-20 mM) used as the complex-forming ligand added to the background electrolyte. Five initial experiments were performed and the response surface was calculated using the relative resolution product as criterion. Three additional experiments were sufficient to establish a stable optimum, with which all 11 metal ions were separated and well spread in the electropherogram. The total analysis time was less than 5 min.

  15. Electrolyte Composition of Mink (Mustela vison Erythrocytes and Active Cation Transporters of the Cell Membrane

    Directory of Open Access Journals (Sweden)

    Clausen TN

    2001-06-01

    Full Text Available Red blood cells from mink (Mustela vison were characterized with respect to their electrolyte content and their cell membranes with respect to enzymatic activity for cation transport. The intra- and extracellular concentrations of Na+, K+, Cl-, Ca2+ and Mg2+ were determined in erythrocytes and plasma, respectively. Plasma and red cell water content was determined, and molal electrolyte concentrations were calculated. Red cells from male adult mink appeared to be of the low-K+, high-Na+ type as seen in other carnivorous species. The intracellular K+ concentration is slightly higher than the extracellular one and the plasma-to-cell chemical gradient for Na+ is weak, though even the molal concentrations may differ significantly. Consistent with the high intracellular Na+ and low K+ concentrations, a very low or no ouabain-sensitive Na+,K+-ATPase activity and no K+-activated pNPPase activity were found in the plasma membrane fraction from red cells. The Cl- and Mg2+ concentrations expressed per liter cell water were significantly higher in red cells than in plasma whereas the opposite was the case with Ca2+. The distribution of Cl- thus does not seem compatible with an inside-negative membrane potential in mink erythrocytes. In spite of a steep calcium gradient across the red cell membrane, neither a calmodulin-activated Ca2+-ATPase activity nor an ATP-activated Ca2+-pNPPase activity were detectable in the plasma membrane fraction. The origin of a supposed primary Ca2+ gradient for sustaining of osmotic balance thus seems uncertain.

  16. A novel lithium/sulfur battery based on sulfur/graphene nanosheet composite cathode and gel polymer electrolyte.

    Science.gov (United States)

    Zhang, Yongguang; Zhao, Yan; Bakenov, Zhumabay

    2014-03-21

    A novel sulfur/graphene nanosheet (S/GNS) composite was prepared via a simple ball milling of sulfur with commercial multi-layer graphene nanosheet, followed by a heat treatment. High-resolution transmission and scanning electronic microscopy observations showed the formation of irregularly interlaced nanosheet-like structure consisting of graphene with uniform sulfur coating on its surface. The electrochemical properties of the resulting composite cathode were investigated in a lithium cell with a gel polymer electrolyte (GPE) prepared by trapping 1 mol dm-3 solution of lithium bistrifluoromethanesulfonamide in tetraethylene glycol dimethyl ether in a polymer matrix composed of poly(vinylidene fluoride-co-hexafluoropropylene)/poly(methylmethacrylate)/silicon dioxide (PVDF-HFP/PMMA/SiO2). The GPE battery delivered reversible discharge capacities of 809 and 413 mAh g-1 at the 1st and 50th cycles at 0.2C, respectively, along with a high coulombic efficiency over 50 cycles. This performance enhancement of the cell was attributed to the suppression of the polysulfide shuttle effect by a collective effect of S/GNS composite cathode and GPE, providing a higher sulfur utilization.

  17. Electrolytic Synthesis of Ni-W-MWCNT Composite Coating for Alkaline Hydrogen Evolution Reaction

    Science.gov (United States)

    Elias, Liju; Hegde, A. Chitharanjan

    2018-01-01

    Nickel-tungsten multi-walled carbon nanotube (Ni-W-MWCNT) composite films were fabricated by an electrodeposition technique, and their electrocatalytic activity toward hydrogen evolution reaction (HER) was studied. Ni-W-MWCNT composite films with a homogeneous dispersion of MWCNTs were deposited from an optimal Ni-W plating bath containing functionalized MWCNTs, under galvanostatic condition. The presence of functionalized MWCNT was found to enhance the induced codeposition of the reluctant metal W and resulted in a W-rich composite coating with improved properties. The electrocatalytic behaviors of Ni-W-MWCNT composite coating toward HER were studied by cyclic voltammetry (CV) and chronopotentiometry techniques in 1.0 M KOH medium. Further, Tafel polarization and electrochemical impedance spectroscopy (EIS) studies were carried out to establish the kinetics of HER on the alloy and composite electrodes. The experimental results revealed that the addition of MWCNTs (having a diameter of around 10-15 nm) into the alloy plating bath has a significant effect on the electrocatalytic behavior of Ni-W alloy deposit. The Ni-W-MWCNT composite coating was found to show better HER activity than the conventional Ni-W alloy coating. The enhanced electrocatalytic activity of Ni-W-MWCNT composite coating is attributed to the MWCNT intersticed in the deposit matrix, evidenced by surface morphology, composition and phase structure of the coating through SEM, EDS and XRD analyses, respectively.

  18. Effects of stimulation technique, anatomical region, and time on human sweat lipid mediator profiles.

    Science.gov (United States)

    Agrawal, Karan; Waller, Justin D; Pedersen, Theresa L; Newman, John W

    2018-01-01

    Few studies compare sampling protocol effect on sweat composition. Here we evaluate the impact of sweat stimulation mode and site of collection on lipid mediator composition. Sweat from healthy males (n=7) was collected weekly for three weeks from the volar forearm following either pilocarpine iontophoresis or exercise, and from the forearm, back and thigh following pilocarpine iontophoresis only. Sweat content of over 150 lipid mediators were measured by liquid chromatography-tandem mass spectrometry. Seventy lipid mediators were routinely detected, including prostanoids, alcohols, diols, epoxides, ketones, nitrolipids, N-acylethanolamides, monoacylglycerols, and ceramides. Detected lipid mediators appeared unaffected by sampling site, though the forearm was the most consistent source of sweat. Pilocarpine-induced sweat showed increased concentrations of most detected compounds. Moreover, lipid mediator concentrations and profiles were temporally stable over the study duration. Sweat therefore appears to be a consistent and anatomically-stable source of lipid mediators, but care must be taken in comparing results obtained from different stimulation techniques. Published by Elsevier Inc.

  19. A wearable multisensing patch for continuous sweat monitoring.

    Science.gov (United States)

    Anastasova, Salzitsa; Crewther, Blair; Bembnowicz, Pawel; Curto, Vincenzo; Ip, Henry Md; Rosa, Bruno; Yang, Guang-Zhong

    2017-07-15

    In sport, exercise and healthcare settings, there is a need for continuous, non-invasive monitoring of biomarkers to assess human performance, health and wellbeing. Here we report the development of a flexible microfluidic platform with fully integrated sensing for on-body testing of human sweat. The system can simultaneously and selectively measure metabolite (e.g. lactate) and electrolytes (e.g. pH, sodium) together with temperature sensing for internal calibration. The construction of the platform is designed such that continuous flow of sweat can pass through an array of flexible microneedle type of sensors (50µm diameter) incorporated in a microfluidic channel. Potentiometric sodium ion sensors were developed using a polyvinyl chloride (PVC) functional membrane deposited on an electrochemically deposited internal layer of Poly(3,4-ethylenedioxythiophene) (PEDOT) polymer. The pH sensing layer is based on a highly sensitive membrane of iridium oxide (IrOx). The amperometric-based lactate sensor consists of doped enzymes deposited on top of a semipermeable copolymer membrane and outer polyurethane layers. Real-time data were collected from human subjects during cycle ergometry and treadmill running. A detailed comparison of sodium, lactate and cortisol from saliva is reported, demonstrating the potential of the multi-sensing platform for tracking these outcomes. In summary, a fully integrated sensor for continuous, simultaneous and selective measurement of sweat metabolites, electrolytes and temperature was achieved using a flexible microfluidic platform. This system can also transmit information wirelessly for ease of collection and storage, with the potential for real-time data analytics. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  20. A convenient electrolytic assembly of graphene-MOF composite thin film and its photoanodic application

    Science.gov (United States)

    Kaur, Rajnish; Kim, Ki-Hyun; Deep, Akash

    2017-02-01

    In the recent past, the metal organic frameworks (MOFs) have been recognized as attractive photosensitizer materials due to their hierarchically ordered structures and attractive light-harvesting characteristics. In this work, we report the application of a graphene-MOF composite as a potential photosensitizer material in dye-sensitized solar cells (DSSCs). A thin film of graphene-MOF hybrid composite was electrochemically assembled on a TiO2/FTO substrate and the different characteristics of the prepared film were investigated. This novel photoanode material hybrid structure demonstrated the potency of an alternative solid-state DSSC configuration. The 2.2% observed power conversion efficiency of the above graphene-MOF composite is a good basis for the further development of graphene-MOF composite-based photoanodes.

  1. PIXE analysis of cystic fibrosis sweat samples with an external proton beam

    Science.gov (United States)

    Sommer, F.; Massonnet, B.

    1987-03-01

    PIXE analysis with an external proton beam is used to study, in four control and five cystic fibrosis children, the elemental composition of sweat samples collected from different parts of the body during entire body hyperthermia. We observe no significant difference of sweat rates and of temperature variations between the two groups during sweat test. The statistical study of results obtained by PIXE analysis allows us to pick out amongst 8 elements studied, 6 elements (Na, Cl, Ca, Mn, Cu, Br) significatively different between the two groups of subjects. Using regression analysis, Na, Cl and Br concentrations could be used in a predictive equation of the state of health.

  2. Sweat as an Efficient Natural Moisturizer.

    Science.gov (United States)

    Shiohara, Tetsuo; Sato, Yohei; Komatsu, Yurie; Ushigome, Yukiko; Mizukawa, Yoshiko

    2016-01-01

    Although recent research on the pathogenesis of allergic skin diseases such as atopic dermatitis has focused on defects in skin genes important for maintaining skin barrier function, the fact that excreted sweat has an overwhelmingly great capacity to increase skin surface hydration and contains moisturizing factors has long been ignored: the increase in water loss induced by these gene defects could theoretically be compensated fully by a significant increase in sweating. In this review, the dogma postulating the detrimental role of sweat in these diseases has been challenged on the basis of recent findings on the physiological functions of sweat, newly recognized sweat gland-/duct-related skin diseases, and therapeutic approaches to the management of these diseases. We are now beginning to appreciate that sweat glands/ducts are a sophisticated regulatory system. Furthermore, depending on their anatomical location and the degree of the impairment, this system might have a different function: sweating responses in sweat glands/ducts located at the folds in hairy skin such as on the trunk and extremities could function as natural regulators that maintain skin hydration under quiescent basal conditions, in addition to the better-studied thermoregulatory functions, which can be mainly mediated by those at the ridges. The normal functioning of sweat could be disturbed in various inflammatory skin diseases. Thus, we should recognize sweating disturbance as an etiologic factor in the development of these diseases. © 2016 S. Karger AG, Basel.

  3. Urea transporters and sweat response to uremia.

    Science.gov (United States)

    Keller, Raymond W; Bailey, James L; Wang, Yanhua; Klein, Janet D; Sands, Jeff M

    2016-06-01

    In humans, urea is excreted in sweat, largely through the eccrine sweat gland. The urea concentration in human sweat is elevated when compared to blood urea nitrogen. The sweat urea nitrogen (UN) of patients with end-stage kidney disease (ESRD) is increased when compared with healthy humans. The ability to produce sweat is maintained in the overwhelming majority of ESRD patients. A comprehensive literature review found no reports of sweat UN neither in healthy rodents nor in rodent models of chronic kidney disease (CKD). Therefore, this study measured sweat UN concentrations in healthy and uremic rats. Uninephrectomy followed by renal artery ligation was used to remove 5/6 of renal function. Rats were then fed a high-protein diet to induce uremia. Pilocarpine was used to induce sweating. Sweat droplets were collected under oil. Sweat UN was measured with a urease assay. Serum UN was measured using a fluorescent ortho-pthalaldehyde reaction. Immunohistochemistry (IHC) was accomplished with a horseradish peroxidase and diaminobenzidine technique. Sweat UN in uremic rats was elevated greater than two times compared to healthy pair-fed controls (220 ± 17 and 91 ± 15 mmol/L, respectively). Post hoc analysis showed a significant difference between male and female uremic sweat UN (279 ± 38 and 177 ± 11 mmol/L, respectively.) IHC shows, for the first time, the presence of the urea transporters UT-B and UT-A2 in both healthy and uremic rat cutaneous structures. Future studies will use this model to elucidate how rat sweat UN and other solute excretion is altered by commonly prescribed diuretics. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  4. Thermal influence on palmar sweating and mental influence on generalized sweating in man.

    Science.gov (United States)

    Ogawa, T

    1975-01-01

    Sweat rates on the forearm and on the palm were simultaneously recorded by resistance hygrometry and the mode of sweating in these areas in response to thermal and non-thermal stimuli were compared with each other. In Series A, periodic infrared irradiation (1 min on, 1 min off) was done to the back of the trunk, and reflex responses in sweat rate were recorded on both test areas. A high correlation was noted between the mean changes in the palmar sweat rate and those in the forearm one during the irradiation cycle in a majority of cases. However the magnitude of the sweat response was much less on the palm than on the forearm. These observations reveal that the central mechanism of palmar sweating may be affected to some extent by the thermoregulatory mechanism. Series B was concerned with the pattern of response in forearm sweating to various non-thermal stimuli. Careful observations showed that the forearm sweating responded diversely to various mental stimuli, unlike the palmar sweating whose response was always an increase. Mental arithmetic, mental testing and physical exercise caused an immediate increase in the palmar sweating but often elicited a transient decrease in the forearm sweating, whereas pain, noise, and emotional stimuli consistently provoked an increase of sweating on the forearm as well as on the palm. These observations suggest that the activities of higher centers, presumably involving neocortex and limbic cortex, exert various influences on the central mechanisms of palmar and generalized sweating.

  5. Polymer Electrolytes

    Science.gov (United States)

    Hallinan, Daniel T.; Balsara, Nitash P.

    2013-07-01

    This review article covers applications in which polymer electrolytes are used: lithium batteries, fuel cells, and water desalination. The ideas of electrochemical potential, salt activity, and ion transport are presented in the context of these applications. Potential is defined, and we show how a cell potential measurement can be used to ascertain salt activity. The transport parameters needed to fully specify a binary electrolyte (salt + solvent) are presented. We define five fundamentally different types of homogeneous electrolytes: type I (classical liquid electrolytes), type II (gel electrolytes), type III (dry polymer electrolytes), type IV (dry single-ion-conducting polymer electrolytes), and type V (solvated single-ion-conducting polymer electrolytes). Typical values of transport parameters are provided for all types of electrolytes. Comparison among the values provides insight into the transport mechanisms occurring in polymer electrolytes. It is desirable to decouple the mechanical properties of polymer electrolyte membranes from the ionic conductivity. One way to accomplish this is through the development of microphase-separated polymers, wherein one of the microphases conducts ions while the other enhances the mechanical rigidity of the heterogeneous polymer electrolyte. We cover all three types of conducting polymer electrolyte phases (types III, IV, and V). We present a simple framework that relates the transport parameters of heterogeneous electrolytes to homogeneous analogs. We conclude by discussing electrochemical stability of electrolytes and the effects of water contamination because of their relevance to applications such as lithium ion batteries.

  6. A Cross-Linking Succinonitrile-Based Composite Polymer Electrolyte with Uniformly Dispersed Vinyl-Functionalized SiO2 Particles for Li-Ion Batteries.

    Science.gov (United States)

    Liu, Kai; Ding, Fei; Liu, Jiaquan; Zhang, Qingqing; Liu, Xingjiang; Zhang, Jinli; Xu, Qiang

    2016-09-14

    A cross-linking succinonitrile (SN)-based composite polymer electrolyte (referred to as "CLPC-CPE"), in which vinyl-functionalized SiO2 particles connect with trimethylolpropane propoxylate triacrylate (TPPTA) monomers by covalent bonds, was prepared by an ultraviolet irradiation (UV-curing) process successfully. Vinyl-functionalized SiO2 particles may react with TPPTA monomers to form a cross-linking network within the SN-based composite polymer electrolyte under ultraviolet irradiation. Vinyl-functionalized SiO2 particles as the fillers of polymer electrolyte may improve both the thermal stability of CLPC-CPE and interfacial compatibility between CLPC-CPE and electrodes effectively. There is no weight loss for CLPC-CPE until above 230 °C. The ionic conductivity of CLPC-CPE may reach 7.02 × 10(-4) S cm(-1) at 25 °C. CLPC-CPE has no significant oxidation current until up to 4.6 V (vs Li/Li(+)). The cell of LiFePO4/CLPC-CPE/Li has presented superior cycle performance and rate capability. The cell of LiFePO4/CLPC-CPE/Li may deliver a high discharge capacity of 154.4 mAh g(-1) at a rate of 0.1 C after 100 charge-discharge cycles, which is similar than that of the control cell of LiFePO4/liquid electrolyte/Li. Furthermore, the cell of LiFePO4/CLPC-CPE/Li can display a high discharge capacity of 112.7 mAh g(-1) at a rate of 2 C, which is higher than that of the cells assembled with other plastic crystal polymer electrolyte reported before obviously.

  7. A new paradigm in sweat based wearable diagnostics biosensors using Room Temperature Ionic Liquids (RTILs)

    OpenAIRE

    Munje, Rujuta D.; Muthukumar, Sriram; Jagannath, Badrinath; Prasad, Shalini

    2017-01-01

    Successful commercialization of wearable diagnostic sensors necessitates stability in detection of analytes over prolonged and continuous exposure to sweat. Challenges are primarily in ensuring target disease specific small analytes (i.e. metabolites, proteins, etc.) stability in complex sweat buffer with varying pH levels and composition over time. We present a facile approach to address these challenges using RTILs with antibody functionalized sensors on nanoporous, flexible polymer membran...

  8. A Nafion-Ceria Composite Membrane Electrolyte for Reduced Methanol Crossover in Direct Methanol Fuel Cells

    Directory of Open Access Journals (Sweden)

    Parthiban Velayutham

    2017-02-01

    Full Text Available An alternative Nafion composite membrane was prepared by incorporating various loadings of CeO2 nanoparticles into the Nafion matrix and evaluated its potential application in direct methanol fuel cells (DMFCs. The effects of CeO2 in the Nafion matrix were systematically studied in terms of surface morphology, thermal and mechanical stability, proton conductivity and methanol permeability. The composite membrane with optimum filler content (1 wt. % CeO2 exhibits a proton conductivity of 176 mS·cm−1 at 70 °C, which is about 30% higher than that of the unmodified membrane. Moreover, all the composite membranes possess a much lower methanol crossover compared to pristine Nafion membrane. In a single cell DMFC test, MEA fabricated with the optimized composite membrane delivered a peak power density of 120 mW·cm−2 at 70 °C, which is about two times higher in comparison with the pristine Nafion membrane under identical operating conditions.

  9. Distinguishing hyperhidrosis and normal physiological sweat production

    DEFF Research Database (Denmark)

    Thorlacius, Linnea; Gyldenløve, Mette; Zachariae, Claus

    2015-01-01

    of this study was to establish reference intervals for normal physiological axillary and palmar sweat production. METHODS: Gravimetric testing was performed in 75 healthy control subjects. Subsequently, these results were compared with findings in a cohort of patients with hyperhidrosis and with the results...... 100 mg/5 min. CONCLUSIONS: A sweat production rate of 100 mg/5 min as measured by gravimetric testing may be a reasonable cut-off value for distinguishing axillary and palmar hyperhidrosis from normal physiological sweat production....

  10. Sweating the small stuff: adequacy and accuracy in sweat chloride determination.

    Science.gov (United States)

    DeMarco, Mari L; Dietzen, Dennis J; Brown, Sarah M

    2015-04-01

    Sweat chloride testing is the gold standard for diagnosis of cystic fibrosis (CF). Our objectives were to: 1) describe variables that determine sweat rate; 2) determine the analytic and diagnostic capacity of sweat chloride analysis across the range of observed sweat rates; and 3) determine the biologic variability of sweat chloride concentration. A retrospective analysis was performed using data from all sweat chloride tests performed at St. Louis Children's Hospital over a 21-month period. A total of 1397 sweat chloride tests (1155 sufficient [≥75 mg], 242 insufficient [sweat weight collected from forearms was statistically greater than that collected from legs. There was a negligible correlation between sweat weight and chloride concentration (r=-0.06). The mean individual biologic CV calculated from individuals with two or more sweat collections ≥75 mg was 13.1% (95% CI: 11.3-14.9%; range 0-88%) yielding a reference change value of 36%. Using 60 mmol/L as the diagnostic chloride cutoff, 100% of CF cases were detected whether a minimum sweat weight of 75, 40, or 20 mg was required. 1) Collection of sweat from forearms is preferable to upper legs, particularly in very young infants; 2) sweat chloride concentrations are not highly dependent upon sweat rate; 3) a change in sweat chloride concentration exceeding 36% may be considered a clinically significant response to cystic fibrosis transmembrane receptor targeted therapy, and 4) sweat collections of less than 75 mg provide clinically accurate information. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  11. The mechanism of eccrine sweat pore plugging by aluminium salts using microfluidics combined with small angle X-ray scattering.

    Science.gov (United States)

    Bretagne, Alice; Cotot, Franck; Arnaud-Roux, Mireille; Sztucki, Michael; Cabane, Bernard; Galey, Jean-Baptiste

    2017-05-24

    Aluminium salts are widely used to control sweating for personal hygiene purposes. Their mechanism of action as antiperspirants was previously thought to be a superficial plugging of eccrine sweat pores by the aluminium hydroxide gel. Here we present a microfluidic T junction device that mimics sweat ducts, and is designed for the real time study of interactions between sweat and ACH (Aluminium Chloro Hydrate) under conditions that lead to plug formation. We used this device to image and measure the diffusion of aluminium polycationic species in sweat counter flow. We report the results of small angle X-ray scattering experiments performed to determine the structure and composition of the plug, using BSA (Bovine Serum Albumin) as a model of sweat proteins. Our results show that pore occlusion occurs as a result of the aggregation of sweat proteins by aluminium polycations. Mapping of the device shows that this aggregation is initiated in the T junction at the location where the flow of aluminium polycations joins the flow of BSA. The mechanism involves two stages: (1) a nucleation stage in which aggregates of protein and polycations bind to the wall of the sweat duct and form a tenuous membrane, which extends across the junction; (2) a growth stage in which this membrane collects proteins that are carried by hydrodynamic flow in the sweat channel and polycations that diffuse into this channel. These results could open up perspectives to find new antiperspirant agents with an improved efficacy.

  12. Sweat function in the diabetic foot

    Directory of Open Access Journals (Sweden)

    Markendeya Nirmala

    2004-01-01

    Full Text Available Background: Autonomic dysfunction, an early manifestation of diabetic neuropathy, presents with altered sweating patterns, leading to dryness and fissuring. We conducted a study to assess the sweat function in the diabetic foot and to determine the interrelation between the duration of diabetes, sensation, fissuring, and sweating. Methods: The sweat function was assessed in 30 diabetic patients, 28 of whom had fissuring of the feet, using Ninhydrin impregnated discs. Results: There was a significant association between fissuring and sensation, but not between the duration of diabetes and fissuring and between loss of sweating and fissuring. In 18 patients (60% there was impairment or absence of sweating in the presence of normal sensation. Conclusion: Although fissuring increases with long-standing diabetes and sweating is reduced in diabetic patients with fissures on the foot, the correlation between these entities was not statistically significant. Since 60% patients had altered sweating in the presence of normal sensations, the sweat test can be used as an early indicator of diabetic neuropathy.

  13. Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat.

    Science.gov (United States)

    Meyer, F; Laitano, O; Bar-Or, O; McDougall, D; Heigenhauser, G J F; Heingenhauser, G J F

    2007-01-01

    The dependence of sweat composition and acidity on sweating rate (SR) suggests that the lower SR in children compared to adults may be accompanied by a higher level of sweat lactate (Lac-) and ammonia (NH3) and a lower sweat pH. Four groups (15 girls, 18 boys, 8 women, 8 men) cycled in the heat (42 degrees C, 20% relative humidity) at 50% VO2max for two 20-min bouts with a 10-min rest before bout 1 and between bouts. Sweat was collected into plastic bags attached to the subject's lower back. During bout 1, sweat from girls and boys had higher Lac- concentrations (23.6 +/- 1.2 and 21.2 +/- 1.7 mM; P sweat from women and men (18.2 +/- 1.9 and 14.8 +/- 1.6 mM, respectively), but Lac- was weakly associated with SR (P > 0.05; r = -0.27). Sweat Lac- concentration dropped during exercise bout 2, reaching similar levels among all groups (overall mean = 13.7 +/- 0.4 mM). Children had a higher sweat NH3 than adults during bout 1 (girls = 4.2 +/- 0.4, boys = 4.6 +/- 0.6, women = 2.7 +/- 0.2, and men = 3.0 +/- 0.2 mM; P sweat pH was lower than that of adults (mean +/- SEM, girls = 5.4 +/- 0.2, boys = 5.0 +/- 0.1, women = 6.2 +/- 0.5, and men = 6.2 +/- 0.4 for bout 1, and girls = 5.4 +/- 0.2, boys = 6.5 +/- 0.5, women = 5.2 +/- 0.2, and men = 6.9 +/- 0.4 for bout 2). This may have favored NH3 transport from plasma to sweat as accounted for by a significant correlation between sweat NH3 and H+ (r = 0.56). Blood pH increased from rest (mean +/- SEM; 7.3 +/- 0.02) to the end of exercise (7.4 +/- 0.01) without differences among groups. These results, however, are representative of sweat induced by moderate exercise in the absence of acidosis.

  14. Blood, sweat and plaster casts: Reviewing the history, composition, and scientific value of the Raymond A. Dart Collection of African Life and Death Masks.

    Science.gov (United States)

    Houlton, T M R; Billings, B K

    2017-10-01

    This paper addresses the history, composition and scientific value of one of the most comprehensive facemask collections in Africa, the Raymond A. Dart Collection of African Life and Death Masks. Housed within the School of Anatomical Sciences at the University of the Witwatersrand (South Africa), it comprises 1110 masks (397 life, 487 death, 226 unknown). Life masks represent populations throughout Africa; death masks predominately southern Africa. Males preponderate by 75%. Recorded ages are error prone, but suggest most life masks are those of <35 year-olds, death masks of 36+ year-olds. A total of 241 masks have associated skeletons, 209 presenting a complete skull. Life masks date between 1927 and c.1980s, death masks 1933 and 1963. This historical collection presents uncanny associations with outmoded typological and evolutionary theories. Once perceived an essential scientific resource, performed craniofacial superimpositions identify the nose as the only stable feature maintained, with the remaining face best preserved in young individuals with minimal body fat. The facemask collection is most viable for teaching and research within the history of science, specifically physical anthropology, and presents some value to craniofacial identification. Future research will have to be conducted with appropriate ethical considerations to science and medicine. Copyright © 2017 Elsevier GmbH. All rights reserved.

  15. Effects of TiO{sub 2} addition on ionic conductivity of PVC/PEMA blend based composite polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Subban, R. H. Y. [Institute of Science Universiti Teknologi MARA 40450 Shah Alam Selangor Malaysia (Malaysia); Facultyof Applied Sciences Universiti Teknologi MARA40450 Shah Alam Selangor Malaysia (Malaysia); Sukri, Nursyazwani [Facultyof Applied Sciences Universiti Teknologi MARA40450 Shah Alam Selangor Malaysia (Malaysia)

    2015-08-28

    PVC/PEMA blend based polymer electrolytes with lithium bistrifluoromethane sulfonimide (LiN(CF{sub 3}SO{sub 2}){sub 2}) and PVC/PEMA/(LiN(CF{sub 3}SO{sub 2}){sub 2}-TiO{sub 2} films were prepared by solution cast technique. The sample containing 35 wt. % LiN(CF{sub 3}SO{sub 2}){sub 2} exhibited the highest conductivity of 1.75 × 10{sup −5} Scm{sup −1}. The conductivity of the sample increased to 2.12 × 10{sup −5} Scm{sup −1} and 4.61 × 10{sup −5} Scm{sup −1} when 4 wt. % and 10 wt. % of titanium dioxide (TiO{sub 2}) was added to the sample at 65 wt. % PVC/PEMA-35 wt. % LiN(CF{sub 3}SO{sub 2}){sub 2} composition respectively. The low increase in conductivity is attributed to two competing factors: increase in crystallinity as accounted by X-Ray diffraction (XRD) and decrease in glass transition temperature as accounted by differential scanning calorimetry (DSC)

  16. Stabilizing the Performance of High-Capacity Sulfur Composite Electrodes by a New Gel Polymer Electrolyte Configuration.

    Science.gov (United States)

    Agostini, Marco; Lim, Du Hyun; Sadd, Matthew; Fasciani, Chiara; Navarra, Maria Assunta; Panero, Stefania; Brutti, Sergio; Matic, Aleksandar; Scrosati, Bruno

    2017-09-11

    Increased pollution and the resulting increase in global warming are drawing attention to boosting the use of renewable energy sources such as solar or wind. However, the production of energy from most renewable sources is intermittent and thus relies on the availability of electrical energy-storage systems with high capacity and at competitive cost. Lithium-sulfur batteries are among the most promising technologies in this respect due to a very high theoretical energy density (1675 mAh g(-1) ) and that the active material, sulfur, is abundant and inexpensive. However, a so far limited practical energy density, life time, and the scaleup of materials and production processes prevent their introduction into commercial applications. In this work, we report on a simple strategy to address these issues by using a new gel polymer electrolyte (GPE) that enables stable performance close to the theoretical capacity of a low cost sulfur-carbon composite with high loading of active material, that is, 70 % sulfur. We show that the GPE prevents sulfur dissolution and reduces migration of polysulfide species to the anode. This functional mechanism of the GPE membranes is revealed by investigating both its morphology and the Li-anode/GPE interface at various states of discharge/charge using Raman spectroscopy. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Composite electrolytes of polyethylene oxides/garnets interfacially wetted by ionic liquid for room-temperature solid-state lithium battery

    Science.gov (United States)

    Huo, Hanyu; Zhao, Ning; Sun, Jiyang; Du, Fuming; Li, Yiqiu; Guo, Xiangxin

    2017-12-01

    Paramount attention has been paid on solid polymer electrolytes due to their potential in enhancement of energy density as well as improvement of safety. Herein, the composite electrolytes consisting of Li-salt-free polyethylene oxides and 200 nm-sized Li6.4La3Zr1.4Ta0.6O12 particles interfacially wetted by [BMIM]TF2N of 1.8 μL cm-2 have been prepared. Such wetted ionic liquid remains the solid state of membrane electrolytes and decreases the interface impedance between the electrodes and the electrolytes. There is no release of the liquid phase from the PEO matrix when the pressure of 5.0 × 104 Pa being applied for 24 h. The interfacially wetted membrane electrolytes show the conductivity of 2.2 × 10-4 S cm-1 at 20 °C, which is one order of magnitude greater than that of the membranes without the wetted ionic liquids. The conduction mechanism is related to a large number of lithium ions releasing from Li6.4La3Zr1.4Ta0.6O12 particles and the improved conductive paths along the ion-liquid-wetted interfaces between the polymer matrix and ceramic grains. When the membranes being used in the solid-state LiFePO4/Li and LiFe0.15Mn0.85PO4/Li cells at 25 °C, the excellent rate capability and superior cycle stability has been shown. The results provide a new prospect for solid polymer electrolytes used for room-temperature solid-state lithium batteries.

  18. Surface composition effect of nitriding Ni-free stainless steel as bipolar plate of polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yang; Shironita, Sayoko [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Nakatsuyama, Kunio [Nakatsuyama Heat Treatment Co., Ltd., 1-1089-10, Nanyou, Nagaoka, Niigata 940-1164 (Japan); Souma, Kenichi [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Hitachi Industrial Equipment Systems Co., Ltd., 3 Kanda Neribei, Chiyoda, Tokyo 101-0022 (Japan); Umeda, Minoru, E-mail: mumeda@vos.nagaokaut.ac.jp [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan)

    2016-12-01

    Graphical abstract: The anodic current densities in the passive region of nitrided SUS445-N stainless steel are lower than those of a non heat-treated SUS445 stainless steel and heat-treated SUS445-Ar stainless steel under an Ar atmosphere. It shows a better corrosion resistance for the SUS445 stainless steel after the nitriding heat treatment. - Highlights: • The nitriding heat treatment was carried out using Ni-free SUS445 stainless steel. • The corrosion resistance of the nitrided SUS445-N stainless steel was improved. • The structure of the nitrided SUS445-N stainless steel changed from α-Fe to γ-Fe. • The surface elemental components present in the steels affect the corrosion resistance. - Abstract: In order to increase the corrosion resistance of low cost Ni-free SUS445 stainless steel as the bipolar plate of a polymer electrolyte fuel cell, a nitriding surface treatment experiment was carried out in a nitrogen atmosphere under vacuum conditions, while an Ar atmosphere was used for comparison. The electrochemical performance, microstructure, surface chemical composition and morphology of the sample before and after the electrochemical measurements were investigated using linear sweep voltammetry (LSV), X-ray diffraction (XRD), glow discharge optical emission spectroscopy (GDS) and laser scanning microscopy (LSM) measurements. The results confirmed that the nitriding heat treatment not only increased the corrosion resistance, but also improved the surface conductivity of the Ni-free SUS445 stainless steel. In contrast, the corrosion resistance of the SUS445 stainless steel decreased after heat treatment in an Ar atmosphere. These results could be explained by the different surface compositions between these samples.

  19. Numerical investigation of the effect of cathode catalyst layer structure and composition on polymer electrolyte membrane fuel cell performance

    Science.gov (United States)

    Kamarajugadda, Sai; Mazumder, Sandip

    The effect of the cathode catalyst layer's structure and composition on the overall performance of a polymer electrolyte membrane fuel cell (PEMFC) is investigated numerically. The starting point of the sub-grid scale catalyst layer model is the well-known flooded agglomerate concept. The proposed model addresses the effects of ionomer (Nafion) loading, catalyst (platinum) loading, platinum/carbon ratio, agglomerate size and cathode layer thickness. The sub-grid scale model is first validated against experimental data and previously published results, and then embedded within a two-dimensional validated computational fluid dynamics code that can predict the overall performance of the fuel cell. The integrated model is then used to explore a wide range of the compositional and structural parameter space, mentioned earlier. In each case, the model is able to correctly predict the trends observed by past experimental studies. It is found that the performance trends are often different at intermediate versus high current densities-the former being governed by agglomerate-scale (or local) losses, while the latter is governed by catalyst layer thickness-scale (or global) losses. The presence of an optimal performance with varying Nafion content in the cathode is more due to the local agglomerate-scale mass transport and conductivity losses in the polymer coating around the agglomerates than due to the amount of Nafion within the agglomerate. It is also found that platinum mass loading needs to be at a moderate level in order to optimize fuel cell performance, even if cost is to be disregarded.

  20. Highly abundant defense proteins in human sweat as revealed by targeted proteomics and label free quantification mass spectrometry

    Science.gov (United States)

    Csősz, Éva; Emri, Gabriella; Kalló, Gergő; Tsaprailis, George; Tőzsér, József

    2015-01-01

    BACKGROUND The healthy human skin with its effective antimicrobial defense system forms an efficient barrier against invading pathogens. There is evidence suggesting that the composition of this chemical barrier varies between diseases, making the easily-collected sweat an ideal candidate for biomarker discoveries. OBJECTIVE Our aim was to provide information about the normal composition of the sweat, and to study the chemical barrier found at the surface of skin. METHODS Sweat samples from healthy individuals were collected during sauna bathing, and the global protein panel was analyzed by label-free mass spectrometry. SRM-based targeted proteomic methods were designed and stable isotope labeled reference peptides were used for method validation. RESULTS 95 sweat proteins were identified, 20 of them were novel proteins. It was shown that dermcidin is the most abundant sweat protein, and along with apolipoprotein D, clusterin, prolactin inducible protein and serum albumin, they make up 91% of secreted sweat proteins. The roles of these highly abundant proteins were reviewed; all of which have protective functions, highlighting the importance of sweat glands in composing the first line of innate immune defense system, and maintaining the epidermal barrier integrity. CONCLUSION Our findings in regards to the proteins forming the chemical barrier of the skin as determined by label free quantification and targeted proteomics methods are in accordance with previous studies, and can be further used as a starting point for non-invasive sweat biomarker research. PMID:26307449

  1. Water and electrolyte replenishment in the exercising child.

    Science.gov (United States)

    Bar-Or, O; Wilk, B

    1996-06-01

    This article reviews studies, mostly from the authors' laboratory, on children's sweating rates and composition, voluntary drinking patterns during prolonged exercise in the heat, taste perception of beverages, and the importance of fluid flavor and composition in preventing voluntary dehydration. Subjects were children, exposed for 90 to 180 min to intermittent bouts of cycling (45-50% maximal O2 uptake) in a climatic chamber (mostly at 35 degrees C, 40-50% relative humidity). There were five main findings: When given unflavored water ad libitum, children dehydrated progressively and their core temperature increased faster than in adults. When offered drinks with various flavors, children preferred grape to other flavors. When given grape-flavored water during intermittent exercise in the heat, children voluntarily drank 44.5% more than with unflavored water. When given grape-flavored carbohydrate-electrolyte solution, they voluntarily drank 91% more than with unflavored water. Finally, such consumption of carbohydrate-electrolyte solution was sufficient to prevent voluntary dehydration during 180-min intermittent exercise in the heat.

  2. A Dendrite-Free Lithium Metal Battery Model Based on Nanoporous Polymer/Ceramic Composite Electrolytes and High-Energy Electrodes.

    Science.gov (United States)

    Tu, Zhengyuan; Lu, Yingying; Archer, Lynden

    2015-06-10

    Nanoporous polymer/ceramic composite electrolytes that suppress dendrite growth in full-cell, high-energy secondary lithium metal batteries are reported. The battery cathode design used in the study is energetically balanced with the metallic lithium anode. The results reported show that such batteries can stably operate for over 1000 h without signs of short circuit. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Precise measurement of instantaneous volume of eccrine sweat gland in mental sweating by optical coherence tomography

    Science.gov (United States)

    Sugawa, Yoshihiko; Fukuda, Akihiro; Ohmi, Masato

    2015-03-01

    We have demonstrated dynamic analysis of the physiological function of eccrine sweat glands underneath skin surface by optical coherence tomography (OCT). We propose a method for extraction of the target eccrine sweat gland by use of the connected component extraction process and the adaptive threshold method, where the en-face OCT images are constructed by the SS-OCT. Furthermore, we demonstrate precise measurement of instantaneous volume of the sweat gland in response to the external stimulus. The dynamic change of instantaneous volume of eccrine sweat gland in mental sweating is performed by this method during the period of 300 sec with the frame intervals of 3.23 sec.

  4. Study on ion conductivity and crystallinity of composite polymer electrolytes based on poly(ethylene oxide)/poly(acrylonitrile) containing nano-sized Al2O3 fillers.

    Science.gov (United States)

    Kim, Mingyeong; Lee, Lyungyu; Jung, Yongju; Kim, Seok

    2013-12-01

    In this paper, composite polymer electrolytes were prepared by a blend of poly(ethylene oxide) (PEO) and poly(acrylonitrile) (PAN) as a polymer matrix, ethylene carbonate as a plasticizer, LiClO4 as a salt, and by containing a different content of nano-sized Al2O3. The composite films were prepared by using the solution casting method. The crystallinity and ionic conductivity of the polymer electrolytes was investigated using X-ray diffraction (XRD) and AC impedance method, respectively. The morphology of composite polymer electrolyte film was analyzed by SEM method. From the experimental results, by increasing the Al2O3 content, the crystallinity of PEO was reduced, and the ionic conductivity was increased. In particular, by a doping of 15 wt.% Al2O3 in PEO/PAN polymer blend, the CPEs showed the superior ionic conductivity. However, when Al2O3 content exceeds 15 wt.%, the ionic conductivity was decreased. From the surface morphology, it was concluded that the ionic conductivity was decreased because the CPEs showed a heterogenous morphology due to immiscibility or aggregation of the ceramic filler within the polymer matrix.

  5. Sweating Like a Pig: Physics or Irony?

    Science.gov (United States)

    Bohren, Craig F.

    2016-01-01

    In his interesting and informative book "Is That a Fact?," Joe Schwarcz avers that pigs do not sweat and the saying "sweating like a pig" originates in iron smelting. Oblong pieces of hot iron, with a fancied resemblance to a sow with piglets, cool in sand to the dew point of the surrounding air, and hence water condenses on…

  6. Usefulness of Sweat Management for Patients with Adult Atopic Dermatitis, regardless of Sweat Allergy: A Pilot Study

    OpenAIRE

    Kaneko, Sakae; Murota, Hiroyuki; Murata, Susumu; Katayama, Ichiro; Morita, Eishin

    2017-01-01

    Background. Sweat is an aggravating factor in atopic dermatitis (AD), regardless of age. Sweat allergy may be involved in AD aggravated by sweating. Objective. We investigated whether sweat exacerbates adult AD symptoms and examined the extent of sweat allergy’s involvement. Method. We asked 34 AD patients (17 men, 17 women; mean age: 27.8 years) to record the extent to which sweat aggravated their symptoms on a 10-point numerical scale. Participant responses were compared with histamine rele...

  7. Photoelectrochemical properties of ZnO nanocrystals/MEH-PPV composite: The effects of nanocrystals synthetic route, film deposition and electrolyte composition

    Energy Technology Data Exchange (ETDEWEB)

    Petrella, A. [Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e Chimica, Politecnico di Bari, Via Orabona 4, 70125 Bari (Italy); Curri, M.L.; Striccoli, M. [CNR IPCF Sez. Bari c/o Dip. Chimica, Università di Bari, Via Orabona 4, 70126 Bari (Italy); Agostiano, A. [Dipartimento di Chimica, Università di Bari, via Orabona 4, 70126 Bari (Italy); CNR IPCF Sez. Bari c/o Dip. Chimica, Università di Bari, Via Orabona 4, 70126 Bari (Italy); Cosma, P., E-mail: pinalysa.cosma@uniba.it [Dipartimento di Chimica, Università di Bari, via Orabona 4, 70126 Bari (Italy); CNR IPCF Sez. Bari c/o Dip. Chimica, Università di Bari, Via Orabona 4, 70126 Bari (Italy)

    2015-11-30

    This paper reports a study on the photoelectrochemical processes occurring at the interface of ZnO nanocrystals/MEH-PPV composites. Colloidal chemical routes were used to obtain size controlled non-hydrolytic ZnO nanocrystals (NCs) dispersible in organic solvents, while a low molecular weight poly[2-methoxy-5-(2′-ethyl-hexyloxy)phenylene vinylene] (MEH-PPV), characterized by high degree of structural order, was synthesized via an organometallic method. The optical properties of the nanocomposite material were comprehensively investigated on solution and on films deposited by spin coating. Remarkably, a significant fluorescence quenching of the polymer at the MEH-PPV/ZnO junction was observed. Photoelectrochemical measurements demonstrated that the photoactivity of the composite material was significantly improved in the case of non-hydrolytic NCs with respect to hydrolytic route prepared ZnO. Moreover, the effective role of the organic/inorganic blend to improve the charge transfer with respect to the double layer hetero-junction was confirmed, thanks to the extended interfaces which enable an effective electron transfer between the hetero-junction components. The system was also studied at different film thicknesses and electrolyte compositions. The results indicated that film photoactivity increased with film thickness up to 300 nm due to the presence of a large number of interfaces, while the change of cation size influenced the ionic conductivity through the nanocomposite film. It was shown that efficient photoconductivity requires not only efficient charge separation, but also efficient transport of the carriers to the electrodes without recombination. - Highlights: • The photoelectrochemical processes at ZnO nanocrystals/MEH-PPV hetero-junction were studied. • Fluorescence quenching of the polymer at the MEH-PPV/ZnO interface was observed. • Non-hydrolytic ZnO junction showed higher photocurrents than hydrolytic equivalent. • The blends showed

  8. Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

    Directory of Open Access Journals (Sweden)

    F. Meyer

    Full Text Available The dependence of sweat composition and acidity on sweating rate (SR suggests that the lower SR in children compared to adults may be accompanied by a higher level of sweat lactate (Lac- and ammonia (NH3 and a lower sweat pH. Four groups (15 girls, 18 boys, 8 women, 8 men cycled in the heat (42ºC, 20% relative humidity at 50% VO2max for two 20-min bouts with a 10-min rest before bout 1 and between bouts. Sweat was collected into plastic bags attached to the subject's lower back. During bout 1, sweat from girls and boys had higher Lac- concentrations (23.6 ± 1.2 and 21.2 ± 1.7 mM; P 0.05; r = -0.27. Sweat Lac- concentration dropped during exercise bout 2, reaching similar levels among all groups (overall mean = 13.7 ± 0.4 mM. Children had a higher sweat NH3 than adults during bout 1 (girls = 4.2 ± 0.4, boys = 4.6 ± 0.6, women = 2.7 ± 0.2, and men = 3.0 ± 0.2 mM; P < 0.05. This difference persisted through bout 2 only in females. On average, children's sweat pH was lower than that of adults (mean ± SEM, girls = 5.4 ± 0.2, boys = 5.0 ± 0.1, women = 6.2 ± 0.5, and men = 6.2 ± 0.4 for bout 1, and girls = 5.4 ± 0.2, boys = 6.5 ± 0.5, women = 5.2 ± 0.2, and men = 6.9 ± 0.4 for bout 2. This may have favored NH3 transport from plasma to sweat as accounted for by a significant correlation between sweat NH3 and H+ (r = 0.56. Blood pH increased from rest (mean ± SEM; 7.3 ± 0.02 to the end of exercise (7.4 ± 0.01 without differences among groups. These results, however, are representative of sweat induced by moderate exercise in the absence of acidosis.

  9. Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

    Directory of Open Access Journals (Sweden)

    F. Meyer

    2007-01-01

    Full Text Available The dependence of sweat composition and acidity on sweating rate (SR suggests that the lower SR in children compared to adults may be accompanied by a higher level of sweat lactate (Lac- and ammonia (NH3 and a lower sweat pH. Four groups (15 girls, 18 boys, 8 women, 8 men cycled in the heat (42ºC, 20% relative humidity at 50% VO2max for two 20-min bouts with a 10-min rest before bout 1 and between bouts. Sweat was collected into plastic bags attached to the subject's lower back. During bout 1, sweat from girls and boys had higher Lac- concentrations (23.6 ± 1.2 and 21.2 ± 1.7 mM; P 0.05; r = -0.27. Sweat Lac- concentration dropped during exercise bout 2, reaching similar levels among all groups (overall mean = 13.7 ± 0.4 mM. Children had a higher sweat NH3 than adults during bout 1 (girls = 4.2 ± 0.4, boys = 4.6 ± 0.6, women = 2.7 ± 0.2, and men = 3.0 ± 0.2 mM; P < 0.05. This difference persisted through bout 2 only in females. On average, children's sweat pH was lower than that of adults (mean ± SEM, girls = 5.4 ± 0.2, boys = 5.0 ± 0.1, women = 6.2 ± 0.5, and men = 6.2 ± 0.4 for bout 1, and girls = 5.4 ± 0.2, boys = 6.5 ± 0.5, women = 5.2 ± 0.2, and men = 6.9 ± 0.4 for bout 2. This may have favored NH3 transport from plasma to sweat as accounted for by a significant correlation between sweat NH3 and H+ (r = 0.56. Blood pH increased from rest (mean ± SEM; 7.3 ± 0.02 to the end of exercise (7.4 ± 0.01 without differences among groups. These results, however, are representative of sweat induced by moderate exercise in the absence of acidosis.

  10. Exercise-induced trace mineral element concentration in regional versus whole-body wash-down sweat.

    Science.gov (United States)

    Baker, Lindsay B; Stofan, John R; Lukaski, Henry C; Horswill, Craig A

    2011-06-01

    Simultaneous whole-body wash-down (WBW) and regional skin surface sweat collections were completed to compare regional patch and WBW sweat calcium (Ca), magnesium (Mg), copper (Cu), manganese (Mn), iron (Fe), and zinc (Zn) concentrations. Athletes (4 men, 4 women) cycled in a plastic open-air chamber for 90 min in the heat. Before exercise, the subjects and cycle ergometer (covered in plastic) were washed with deionized water. After the onset of sweating, sterile patches were attached to the forearm, back, chest, forehead, and thigh and removed on saturation. After exercise, the subjects and cycle ergometer were washed with 5 L of 15-mM ammonium sulfate solution to collect all sweat minerals and determine the volume of unevaporated sweat. Control trials were performed to measure mineral contamination in regional and WBW methods. Because background contamination in the collection system was high for WBW Mn, Fe, and Zn, method comparisons were not made for these minerals. After correction for minimal background contamination, WBW sweat [Ca], [Mg], and [Cu] were 44.6 ± 20.0, 9.8 ± 4.8, and 0.125 ± 0.069 mg/L, respectively, and 5-site regional (weighted for local sweat rate and body surface area) sweat [Ca], [Mg], and [Cu] were 59.0 ± 15.9, 14.5 ± 4.8, and 0.166 ± 0.031 mg/L, respectively. Five-site regional [Ca], [Mg], and [Cu] overestimated WBW by 32%, 48%, and 33%, respectively. No individual regional patch site or 5-site regional was significantly correlated with WBW sweat [Ca] (r = -.21, p = .65), [Mg] (r = .49, p = .33), or [Cu] (r = .17, p = .74). In conclusion, regional sweat [Ca], [Mg], and [Cu] are not accurate surrogates for or significantly correlated with WBW sweat composition.

  11. Enhanced electrochemical stability and charge storage of MnO{sub 2}/carbon nanotubes composite modified by polyaniline coating layer in acidic electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Changzhou; Su, Linghao; Gao, Bo; Zhang, Xiaogang [College of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, Yudao Street 29, Nanjing 210016 (China)

    2008-10-15

    Manganese dioxide/multiwalled carbon nanotubes (MnO{sub 2}/MWCNTs) were synthesized by chemically depositing MnO{sub 2} onto the surface of MWCNTs wrapped with poly(sodium-p-styrenesulfonate). Then, polyaniline (PANI) with good supercapacitive performance was further coated onto the MnO{sub 2}/MWCNTs composite to form PANI/MnO{sub 2}/MWCNTs organic-inorganic hybrid nanoarchitecture. Electrochemical performance of the hybrid in Na{sub 2}SO{sub 4}-H{sub 2}SO{sub 4} mixed acidic electrolytes was evaluated by cyclic voltammetry (CV) and chronopotentiometry (CP) in detail. Comparative electrochemical tests revealed that the hybrid nanoarchitecture could operate in the acidic medium due to the protective modification of PANI coating layer onto the MnO{sub 2}/MWCNTs composite, and that its electrochemical behavior was greatly dependent upon the concentration of protons in the acidic electrolytes. Here, PANI not only served as a physical barrier to restrain the underlying MnO{sub 2}/MWCNTs composite from reductive-dissolution process so as to make the novel ternary hybrid material work in acidic medium to enhance the utilization of manganese oxide as much as possible, but also was another electroactive material for energy storage in the acidic mixed electrolytes. It was due to the existence of PNAI layer that an even larger specific capacitance (SC) of 384 F g{sup -1} and a much better SC retention of 79.9% over 1000 continuous charge/discharge cycles than those for the MnO{sub 2}/MWCNTs nanocomposite were delivered for the hybrid in the optimum 0.5 M Na{sub 2}SO{sub 4}-0.5 M H{sub 2}SO{sub 4} mixed acidic electrolyte. (author)

  12. Enhanced electrochemical stability and charge storage of MnO{sub 2}/carbon nanotubes composite modified by polyaniline coating layer in acidic electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Changzhou; Su Linghao; Gao Bo [College of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, Yudao Street 29, Nanjing 210016 (China); Zhang Xiaogang [College of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, Yudao Street 29, Nanjing 210016 (China)], E-mail: azhangxg@163.com

    2008-10-15

    Manganese dioxide/multiwalled carbon nanotubes (MnO{sub 2}/MWCNTs) were synthesized by chemically depositing MnO{sub 2} onto the surface of MWCNTs wrapped with poly(sodium-p-styrenesulfonate). Then, polyaniline (PANI) with good supercapacitive performance was further coated onto the MnO{sub 2}/MWCNTs composite to form PANI/MnO{sub 2}/MWCNTs organic-inorganic hybrid nanoarchitecture. Electrochemical performance of the hybrid in Na{sub 2}SO{sub 4}-H{sub 2}SO{sub 4} mixed acidic electrolytes was evaluated by cyclic voltammetry (CV) and chronopotentiometry (CP) in detail. Comparative electrochemical tests revealed that the hybrid nanoarchitecture could operate in the acidic medium due to the protective modification of PANI coating layer onto the MnO{sub 2}/MWCNTs composite, and that its electrochemical behavior was greatly dependent upon the concentration of protons in the acidic electrolytes. Here, PANI not only served as a physical barrier to restrain the underlying MnO{sub 2}/MWCNTs composite from reductive-dissolution process so as to make the novel ternary hybrid material work in acidic medium to enhance the utilization of manganese oxide as much as possible, but also was another electroactive material for energy storage in the acidic mixed electrolytes. It was due to the existence of PNAI layer that an even larger specific capacitance (SC) of 384 F g{sup -1} and a much better SC retention of 79.9% over 1000 continuous charge/discharge cycles than those for the MnO{sub 2}/MWCNTs nanocomposite were delivered for the hybrid in the optimum 0.5 M Na{sub 2}SO{sub 4}-0.5 M H{sub 2}SO{sub 4} mixed acidic electrolyte.

  13. Impact of sport drinks on sweat composition

    OpenAIRE

    Muraro, Marcela; Zuliani, Claudio; Nesterenko, Ekaterina; Coyle, Shirley; Fitzpatrick, Paula; Warrington, Giles; Matzeu, Giusy; Costa, Ernane; Diamond, Dermot

    2013-01-01

    Introduction: In sport science it is well known that individual diet has an important role in affecting a person’s performance [1]. In this regard, in the last 10-20 years energy and sport drinks have become increasingly popular among elite and amateur athletes. The worldwide consumption of energy drinks increased in 2006 to 906 million gallons [2]. Just in Brazil, from 2008 to 2010, the production of energy drinks doubled [3]. A possible reason for their popularity is that they claim to help...

  14. High Lithium Transference Number Electrolytes via Creation of 3-Dimensional, Charged, Nanoporous Networks from Dense Functionalized Nanoparticle Composites

    KAUST Repository

    Schaefer, Jennifer L.

    2013-03-26

    High lithium transference number, tLi+, electrolytes are desired for use in both lithium-ion and lithium metal rechargeable battery technologies. Historically, low tLi+ electrolytes have hindered device performance by allowing ion concentration gradients within the cell, leading to high internal resistances that ultimately limit cell lifetime, charging rates, and energy density. Herein, we report on the synthesis and electrochemical features of electrolytes based on nanoparticle salts designed to provide high tLi+. The salts are created by cofunctionalization of metal oxide nanoparticles with neutral organic ligands and tethered lithium salts. When dispersed in a conducting fluid such as tetraglyme, they spontaneously form a charged, nanoporous network of particles at moderate nanoparticle loadings. Modification of the tethered anion chemistry from -SO3 - to -SO3BF3 - is shown to enhance ionic conductivity of the electrolytes by facilitating ion pair dissociation. At a particle volume fraction of 0.15, the electrolyte exists as a self-supported, nanoporous gel with an optimum ionic conductivity of 10 -4 S/cm at room temperature. Galvanostatic polarization measurements on symmetric lithium metal cells containing the electrolyte show that the cell short circuit time, tSC, is inversely proportional to the square of the applied current density tSC ∼ J-2, consistent with previously predicted results for traditional polymer-in-salt electrolytes with low tLi+. Our findings suggest that electrolytes with tLi+ ≈ 1 and good ion-pair dissociation delay lithium dendrite nucleation and may lead to improved lithium plating in rechargeable batteries with metallic lithium anodes. © 2013 American Chemical Society.

  15. Bi2O3 and La10Si6O27 composite electrolyte for enhanced performance in solid oxide fuel cells

    Science.gov (United States)

    Hairul Absah, H. Q. Hj; Abu Bakar, M. S.; Zaini, J. Hj; Azad, A.; Ming, L. C.

    2016-03-01

    Adding suitable metal oxide into lanthanum silicate apatite can produce a composite with a good oxygen ion-conducting electrolyte that enhances the performance of solid oxide fuel cells (SOFCs). In this paper we present the synthesis and characterisation of Bi2O3 and La10Si6O27 composite prepared by a solid state reaction. The sintering temperature of the composite was 1500°C for 10 hours with the heating and cooling rates of 10°C per minute. The properties of the resulting composite have been characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), and ionic conductivity measured by an a.c. impedance spectroscopy (IS). Rietveld refinement of XRD data shows that the composition is purely the mixture of Bi2O3 and La10Si6O27 with the unit cell parameters of the main phase as a = 9.9810 (8) and c = 7.3239 (6) Å. The room temperature crystal structure was hexagonal with space group P63/m. The highest ionic conductivity of 1.76 × 10-2 Scm-1 with a corresponding activation energy of 0.39 eV was obtained at 750°C. SEM images show the material is densed enough to use as an electrolyte for SOFCs.

  16. Study on characteristics of PVDF/nano-clay composite polymer electrolyte using PVP as pore-forming agent

    Energy Technology Data Exchange (ETDEWEB)

    Dyartanti, Endah R., E-mail: heru.susanto@undip.ac.id, E-mail: endah-rd@uns.ac.id [Departement of Chemical Engineering, Sebelas Maret University, Surakarta (Indonesia); Department of Chemical Engineering, Diponegoro University, Semarang (Indonesia); Purwanto, Agus [Departement of Chemical Engineering, Sebelas Maret University, Surakarta (Indonesia); Widiasa, I. Nyoman; Susanto, Heru, E-mail: heru.susanto@undip.ac.id, E-mail: endah-rd@uns.ac.id [Department of Chemical Engineering, Diponegoro University, Semarang (Indonesia)

    2016-02-08

    Polyvinylidene fluoride (PVDF) based polymer electrolytes have a high dielectric constant, which can assist in greater ionization of lithium salts. The main advantages of PVDF are its durability in long battery operation and its ability to be a good ion conductor. However, the limitation of this polymer is its crystalline molecular structure. Dispersing nano-particles in the polymer matrix may improve the characteristics of the PVDF polymer. This paper aims to investigate the impact of nano-clay addition on the characteristics of PVDF polymer to be used as a polymer electrolyte membrane. In addition, the effect of poly(vinyl pyrrolidone) (PVP) is also investigated. The membrane was prepared by phase separation method whereas the polymer electrolyte membranes was prepared by immersing into 1 M lithium hexafluorophosphate (LiPF{sub 6}) in ethylene carbonate/dimethyl carbonate (EC/DMC) electrolytes for 1 h. The membranes were characterized by scanning electron microscope (SEM), porosity and electrolyte uptake and performance in battery cell. The results showed that both nano-clay and PVP have significant impacts on the improvement of PVDF membranes to be used as polymer electrolyte.

  17. A new paradigm in sweat based wearable diagnostics biosensors using Room Temperature Ionic Liquids (RTILs).

    Science.gov (United States)

    Munje, Rujuta D; Muthukumar, Sriram; Jagannath, Badrinath; Prasad, Shalini

    2017-05-16

    Successful commercialization of wearable diagnostic sensors necessitates stability in detection of analytes over prolonged and continuous exposure to sweat. Challenges are primarily in ensuring target disease specific small analytes (i.e. metabolites, proteins, etc.) stability in complex sweat buffer with varying pH levels and composition over time. We present a facile approach to address these challenges using RTILs with antibody functionalized sensors on nanoporous, flexible polymer membranes. Temporal studies were performed using both infrared spectroscopic, dynamic light scattering, and impedimetric spectroscopy to demonstrate stability in detection of analytes, Interleukin-6 (IL-6) and Cortisol, from human sweat in RTILs. Temporal stability in sensor performance was performed as follows: (a) detection of target analytes after 0, 24, 48, 96, and 168 hours post-antibody sensor functionalization; and (b) continuous detection of target analytes post-antibody sensor functionalization. Limit of detection of IL-6 in human sweat was 0.2 pg/mL for 0-24 hours and 2 pg/mL for 24-48 hours post-antibody sensor functionalization. Continuous detection of IL-6 over 0.2-200 pg/mL in human sweat was demonstrated for a period of 10 hours post-antibody sensor functionalization. Furthermore, combinatorial detection of IL-6 and Cortisol in human sweat was established with minimal cross-talk for 0-48 hours post-antibody sensor functionalization.

  18. High performance of SDC and GDC core shell type composite electrolytes using methane as a fuel for low temperature SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Irshad, Muneeb; Siraj, Khurram, E-mail: razahussaini786@gmail.com, E-mail: khurram.uet@gmail.com; Javed, Fayyaz; Ahsan, Muhammad; Rafique, Muhammad Shahid [Department of Physics, University of Engineering and Technology, Lahore (Pakistan); Raza, Rizwan, E-mail: razahussaini786@gmail.com, E-mail: khurram.uet@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore (Pakistan); Shakir, Imran [Deanship of scientific research, College of Engineering, PO Box 800, King Saud University, Riyadh 11421 (Saudi Arabia)

    2016-02-15

    Nanocomposites Samarium doped Ceria (SDC), Gadolinium doped Ceria (GDC), core shell SDC amorphous Na{sub 2}CO{sub 3} (SDCC) and GDC amorphous Na{sub 2}CO{sub 3} (GDCC) were synthesized using co-precipitation method and then compared to obtain better solid oxide electrolytes materials for low temperature Solid Oxide Fuel Cell (SOFCs). The comparison is done in terms of structure, crystallanity, thermal stability, conductivity and cell performance. In present work, XRD analysis confirmed proper doping of Sm and Gd in both single phase (SDC, GDC) and dual phase core shell (SDCC, GDCC) electrolyte materials. EDX analysis validated the presence of Sm and Gd in both single and dual phase electrolyte materials; also confirming the presence of amorphous Na{sub 2}CO{sub 3} in SDCC and GDCC. From TGA analysis a steep weight loss is observed in case of SDCC and GDCC when temperature rises above 725 °C while SDC and GDC do not show any loss. The ionic conductivity and cell performance of single phase SDC and GDC nanocomposite were compared with core shell GDC/amorphous Na{sub 2}CO{sub 3} and SDC/ amorphous Na{sub 2}CO{sub 3} nanocomposites using methane fuel. It is observed that dual phase core shell electrolytes materials (SDCC, GDCC) show better performance in low temperature range than their corresponding single phase electrolyte materials (SDC, GDC) with methane fuel.

  19. High performance of SDC and GDC core shell type composite electrolytes using methane as a fuel for low temperature SOFC

    Science.gov (United States)

    Irshad, Muneeb; Siraj, Khurram; Raza, Rizwan; Javed, Fayyaz; Ahsan, Muhammad; Shakir, Imran; Rafique, Muhammad Shahid

    2016-02-01

    Nanocomposites Samarium doped Ceria (SDC), Gadolinium doped Ceria (GDC), core shell SDC amorphous Na2CO3 (SDCC) and GDC amorphous Na2CO3 (GDCC) were synthesized using co-precipitation method and then compared to obtain better solid oxide electrolytes materials for low temperature Solid Oxide Fuel Cell (SOFCs). The comparison is done in terms of structure, crystallanity, thermal stability, conductivity and cell performance. In present work, XRD analysis confirmed proper doping of Sm and Gd in both single phase (SDC, GDC) and dual phase core shell (SDCC, GDCC) electrolyte materials. EDX analysis validated the presence of Sm and Gd in both single and dual phase electrolyte materials; also confirming the presence of amorphous Na2CO3 in SDCC and GDCC. From TGA analysis a steep weight loss is observed in case of SDCC and GDCC when temperature rises above 725 °C while SDC and GDC do not show any loss. The ionic conductivity and cell performance of single phase SDC and GDC nanocomposite were compared with core shell GDC/amorphous Na2CO3 and SDC/ amorphous Na2CO3 nanocomposites using methane fuel. It is observed that dual phase core shell electrolytes materials (SDCC, GDCC) show better performance in low temperature range than their corresponding single phase electrolyte materials (SDC, GDC) with methane fuel.

  20. High performance of SDC and GDC core shell type composite electrolytes using methane as a fuel for low temperature SOFC

    Directory of Open Access Journals (Sweden)

    Muneeb Irshad

    2016-02-01

    Full Text Available Nanocomposites Samarium doped Ceria (SDC, Gadolinium doped Ceria (GDC, core shell SDC amorphous Na2CO3 (SDCC and GDC amorphous Na2CO3 (GDCC were synthesized using co-precipitation method and then compared to obtain better solid oxide electrolytes materials for low temperature Solid Oxide Fuel Cell (SOFCs. The comparison is done in terms of structure, crystallanity, thermal stability, conductivity and cell performance. In present work, XRD analysis confirmed proper doping of Sm and Gd in both single phase (SDC, GDC and dual phase core shell (SDCC, GDCC electrolyte materials. EDX analysis validated the presence of Sm and Gd in both single and dual phase electrolyte materials; also confirming the presence of amorphous Na2CO3 in SDCC and GDCC. From TGA analysis a steep weight loss is observed in case of SDCC and GDCC when temperature rises above 725 °C while SDC and GDC do not show any loss. The ionic conductivity and cell performance of single phase SDC and GDC nanocomposite were compared with core shell GDC/amorphous Na2CO3 and SDC/ amorphous Na2CO3 nanocomposites using methane fuel. It is observed that dual phase core shell electrolytes materials (SDCC, GDCC show better performance in low temperature range than their corresponding single phase electrolyte materials (SDC, GDC with methane fuel.

  1. Precise measurement of volume of eccrine sweat gland in mental sweating by optical coherence tomography

    Science.gov (United States)

    Sugawa, Yoshihiko; Fukuda, Akihiro; Ohmi, Masato

    2015-04-01

    We have demonstrated dynamic analysis of the physiological function of eccrine sweat glands underneath skin surface by optical coherence tomography (OCT). In this paper, we propose a method for extraction of the specific eccrine sweat gland by means of the connected component extraction process and the adaptive threshold method, where the en face OCT images are constructed by the swept-source OCT. In the experiment, we demonstrate precise measurement of the volume of the sweat gland in response to the external stimulus.

  2. Topics in histopathology of sweat gland and sebaceous neoplasms.

    Science.gov (United States)

    Ansai, Shin-Ichi

    2017-03-01

    This article reviews several topics regarding sweat gland and sebaceous neoplasms. First, the clinicopathological characteristics of poroid neoplasms are summarized. It was recently reported that one-fourth of poroid neoplasms are composite tumors and one-fourth are apocrine type lesions. Recent progress in the immunohistochemical diagnosis of sweat gland neoplasms is also reviewed. CD117 can help to distinguish sweat gland or sebaceous tumors from other non-Merkel cell epithelial tumors of the skin. For immunohistochemical differential diagnosis between sweat gland carcinoma (SGC) other than primary cutanesous apocrine carcinoma and skin metastasis of breast carcinoma (SMBC), a panel of antibodies may be useful, including p63 (SGC+ , SMBC- ), CK5/6 (SGC+ , SMBC- ), podoplanin (SGC+ , SMBC- ) and mammaglobin (SGC- , SMBC+ ). Comparison of antibodies used for immunohistochemical diagnosis of sebaceous carcinoma (SC) suggests that adipophilin has the highest sensitivity and specificity. Some authors have found that immunostaining for survivin, androgen receptor and ZEB2/SIP1 has prognostic value for ocular SC, but not extraocular SC. In situ SC is rare, especially extraocular SC, but there have been several recent reports that actinic keratosis and Bowen's disease are the source of invasive SC. Finally, based on recent reports, classification of sebaceous neoplasms into three categories is proposed, which are sebaceoma (a benign neoplasm with well-defined architecture and no atypia), borderline sebaceous neoplasm (low-grade SC; an intermediate tumor with well-defined architecture and nuclear atypia) and SC (a malignant tumor with invasive growth and evident nuclear atypia). © 2017 Japanese Dermatological Association.

  3. Usefulness of Sweat Management for Patients with Adult Atopic Dermatitis, regardless of Sweat Allergy: A Pilot Study.

    Science.gov (United States)

    Kaneko, Sakae; Murota, Hiroyuki; Murata, Susumu; Katayama, Ichiro; Morita, Eishin

    2017-01-01

    Background . Sweat is an aggravating factor in atopic dermatitis (AD), regardless of age. Sweat allergy may be involved in AD aggravated by sweating. Objective. We investigated whether sweat exacerbates adult AD symptoms and examined the extent of sweat allergy's involvement. Method. We asked 34 AD patients (17 men, 17 women; mean age: 27.8 years) to record the extent to which sweat aggravated their symptoms on a 10-point numerical scale. Participant responses were compared with histamine release tests (HRT). Furthermore, 24 of the patients received instructions on methods of sweat management, and their outcomes were evaluated on a 10-point scale. Results. Sweat HRT results were class ≥ 2 in 13 patients, but HRT results were not correlated with the patients' self-assessments of symptom aggravation by sweat. One month after receiving sweat management instructions, a low mean score of 4.6 was obtained regarding whether active sweating was good, but a high mean score of 7.0 was obtained in response to whether the sweat management instructions had been helpful. Conclusion . Our investigation showed that patients' negative impressions of sweat might derive from crude personal experiences that are typically linked to sweating. Sweat management for patients with adult atopic dermatitis was extremely useful regardless of sweat allergy.

  4. Usefulness of Sweat Management for Patients with Adult Atopic Dermatitis, regardless of Sweat Allergy: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Sakae Kaneko

    2017-01-01

    Full Text Available Background. Sweat is an aggravating factor in atopic dermatitis (AD, regardless of age. Sweat allergy may be involved in AD aggravated by sweating. Objective. We investigated whether sweat exacerbates adult AD symptoms and examined the extent of sweat allergy’s involvement. Method. We asked 34 AD patients (17 men, 17 women; mean age: 27.8 years to record the extent to which sweat aggravated their symptoms on a 10-point numerical scale. Participant responses were compared with histamine release tests (HRT. Furthermore, 24 of the patients received instructions on methods of sweat management, and their outcomes were evaluated on a 10-point scale. Results. Sweat HRT results were class ≥ 2 in 13 patients, but HRT results were not correlated with the patients’ self-assessments of symptom aggravation by sweat. One month after receiving sweat management instructions, a low mean score of 4.6 was obtained regarding whether active sweating was good, but a high mean score of 7.0 was obtained in response to whether the sweat management instructions had been helpful. Conclusion. Our investigation showed that patients’ negative impressions of sweat might derive from crude personal experiences that are typically linked to sweating. Sweat management for patients with adult atopic dermatitis was extremely useful regardless of sweat allergy.

  5. Recent Developments in Sweat Analysis and Its Applications

    Directory of Open Access Journals (Sweden)

    Saima Jadoon

    2015-01-01

    Full Text Available Currently, the clinical use of sweat as biofluid is limited. The collection of sweat and its analysis for determining ethanol, drugs, ions, and metals have been encompassed in this review article to assess the merits of sweat compared to other biofluids, for example, blood or urine. Moreover, sweat comprises various biomarkers of different diseases including cystic fibrosis and diabetes. Additionally, the normalization of sampled volume of sweat is also necessary for getting efficient and useful results.

  6. Sex differences in amino acids lost via sweating could lead to differential susceptibilities to disturbances in nitrogen balance and collagen turnover.

    Science.gov (United States)

    Dunstan, R H; Sparkes, D L; Dascombe, B J; Stevens, C J; Murphy, G R; Macdonald, M M; Gottfries, J; Gottfries, C-G; Roberts, T K

    2017-08-01

    Fluid collected during sweating is enriched with amino acids derived from the skin's natural moisturising factors and has been termed "faux" sweat. Little is known about sex differences in sweat amino acid composition or whether faux sweat amino acid losses affect nitrogen balance. Faux sweat collected by healthy adults (n = 47) after exercise, and at rest by chronic fatigue patients, was analysed for amino acid composition. Healthy females had higher total amino acid concentrations in sweat (10.5 ± 1.2 mM) compared with healthy males (6.9 ± 0.9 mM). Females had higher levels of 13 amino acids in sweat including serine, alanine and glycine. Higher hydroxyproline and proline levels suggested greater collagen turnover in females. Modelling indicated that with conservative levels of exercise, amino acid losses in females via faux sweat were triple than those predicted for urine, whereas in males they were double. It was concluded that females were more susceptible to key amino acid loss during exercise and/or hot conditions. Females reporting chronic fatigue had higher levels of methionine in faux sweat than healthy females. Males reporting chronic fatigue had higher levels of numerous amino acids in faux sweat compared to healthy males. Higher amino acid loss in faux sweat associated with chronic fatigue could contribute to a hypometabolic state. Depending on activity levels, climatic conditions and gender, amino acid losses in sweat and skin leachate could influence daily protein turnover where periods of continuously high turnover could lead to a negative net nitrogen balance.

  7. Evolution: plastic sociality in a sweat bee.

    Science.gov (United States)

    Chapuisat, Michel

    2010-11-23

    How and why do bees become social? A transplant experiment shows that sweat bees can adopt a solitary or social lifestyle in response to their environment. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. 7 CFR 29.3554 - Sweating.

    Science.gov (United States)

    2010-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3554 Sweating. The condition of tobacco in the process of fermentation. [30 FR 9207, July...

  9. 7 CFR 29.3553 - Sweated.

    Science.gov (United States)

    2010-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3553 Sweated. The condition of tobacco which has passed through one or more fermentations...

  10. Electrolytically exfoliated graphene-loaded flame-made Ni-doped SnO2 composite film for acetone sensing.

    Science.gov (United States)

    Singkammo, Suparat; Wisitsoraat, Anurat; Sriprachuabwong, Chakrit; Tuantranont, Adisorn; Phanichphant, Sukon; Liewhiran, Chaikarn

    2015-02-11

    In this work, flame-spray-made SnO2 nanoparticles are systematically studied by doping with 0.1-2 wt % nickel (Ni) and loading with 0.1-5 wt % electrolytically exfoliated graphene for acetone-sensing applications. The sensing films (∼12-18 μm in thickness) were prepared by a spin-coating technique on Au/Al2O3 substrates and evaluated for acetone-sensing performances at operating temperatures ranging from 150 to 350 °C in dry air. Characterizations by X-ray diffraction, transmission/scanning electron microscopy, Brunauer-Emmett-Teller analysis, X-ray photoelectron spectroscopy and Raman spectroscopy demonstrated that Ni-doped SnO2 nanostructures had a spheriodal morphology with a polycrystalline tetragonal SnO2 phase, and Ni was confirmed to form a solid solution with SnO2 lattice while graphene in the sensing film after annealing and testing still retained its high-quality nonoxidized form. Gas-sensing results showed that SnO2 sensing film with 0.1 wt % Ni-doping concentration exhibited an optimal response of 54.2 and a short response time of ∼13 s toward 200 ppm acetone at an optimal operating temperature of 350 °C. The additional loading of graphene at 5 wt % into 0.1 wt % Ni-doped SnO2 led to a drastic response enhancement to 169.7 with a very short response time of ∼5.4 s at 200 ppm acetone and 350 °C. The superior gas sensing performances of Ni-doped SnO2 nanoparticles loaded with graphene may be attributed to the large specific surface area of the composite structure, specifically the high interaction rate between acetone vapor and graphene-Ni-doped SnO2 nanoparticles interfaces and high electronic conductivity of graphene. Therefore, the 5 wt % graphene loaded 0.1 wt % Ni-doped SnO2 sensor is a promising candidate for fast, sensitive and selective detection of acetone.

  11. High-energy-density, all-solid-state microsupercapacitors with three-dimensional interdigital electrodes of carbon/polymer electrolyte composite

    Science.gov (United States)

    Pu, Juan; Wang, Xiaohong; Zhang, Tianyi; Li, Siwei; Liu, Jinghe; Komvopoulos, Kyriakos

    2016-01-01

    Novel all-solid-state microsupercapacitors (MSCs) with three-dimensional (3D) electrodes consisting of active materials (i.e., graphene or activated carbon (AC) particles) and polymer electrolyte (PE) designed for high-energy-density storage applications were fabricated and tested in this work. The incorporation of PE in the electrode material enhances the accessibility of electrolyte ions to the surface of active materials and decreases the ion diffusion path during electrochemical charge/discharge. For a scan rate of 5 mV s-1, the MSCs with graphene/PE and AC/PE composite electrodes demonstrate a very high areal capacitance of 95 and 134 mF cm-2, respectively, comparable to that of 3D MSCs with liquid electrolyte. In addition, the graphene/PE MSCs show a ˜70% increase in specific capacitance after 10 000 charge/discharge cycles, attributed to an electro-activation process resulting from ion intercalation between the graphene nanosheets. The AC/PE MSCs also demonstrate excellent stability. The results of this study illustrate the potential of the present 3D MSCs for various high-density solid-state energy storage applications.

  12. Materials space of solid-state electrolytes: unraveling chemical composition-structure-ionic conductivity relationships in garnet-type metal oxides using cheminformatics virtual screening approaches.

    Science.gov (United States)

    Kireeva, Natalia; Pervov, Vladislav S

    2017-08-09

    The organic electrolytes of most current commercial rechargeable Li-ion batteries (LiBs) are flammable, toxic, and have limited electrochemical energy windows. All-solid-state battery technology promises improved safety, cycling performance, electrochemical stability, and possibility of device miniaturization and enables a number of breakthrough technologies towards the development of new high power and energy density microbatteries for electronics with low processing cost, solid oxide fuel cells, electrochromic devices, etc. Currently, rational materials design is attracting significant attention, which has resulted in a strong demand for methodologies that can accelerate the design of materials with tailored properties; cheminformatics can be considered as an efficient tool in this respect. This study was focused on several aspects: (i) identification of the parameters responsible for high Li-ion conductivity in garnet structured oxides; (ii) development of quantitative models to elucidate composition-structure-Li ionic conductivity relationships, taking into account the experimental details of sample preparation; (iii) circumscription of the materials space of solid garnet-type electrolytes, which is attractive for virtual screening. Several candidate compounds have been recommended for synthesis as potential solid state electrolyte materials.

  13. Sweating Like a Pig: Physics or Irony?

    Science.gov (United States)

    Bohren, Craig F.

    2016-03-01

    In his interesting and informative book Is That a Fact?, Joe Schwarcz avers that pigs do not sweat and the saying "sweating like a pig" originates in iron smelting. Oblong pieces of hot iron, with a fancied resemblance to a sow with piglets, cool in sand to the dew point of the surrounding air, and hence water condenses on the "pig." But this explanation, which I have seen on the Internet, lacks a few caveats. It implies that molten iron, solidifying and cooling, anywhere, anytime, accretes liquid water, as if this were a special property of cooling iron. Set aside that real pigs sweat perceptibly from their snouts; kiss a pig and verify for yourself. Pigs also sweat imperceptibly. Imperceptible (insensible) perspiration is water vapor from the skin and lungs exuded without sensible condensation. That from humans is about 1 liter/day. Sweat is 99% liquid water, NaCl the dominant solute, secreted quickly, sometimes profusely, by subcutaneous sweat glands in response to thermal stress, in contrast to the slow, continuous diffusion of water vapor through skin.

  14. Changes in the index of sweat ion concentration with increasing sweat during passive heat stress in humans.

    Science.gov (United States)

    Shamsuddin, A K M; Yanagimoto, S; Kuwahara, T; Zhang, Y; Nomura, C; Kondo, N

    2005-06-01

    To investigate the pattern changes in the index of sweat ion concentration at skin surface with increasing sweat during passive heat stress in humans, we measured conductivity of the perfused water with sweat as the index of sweat ion concentration and sweat rate, continuously at the chest skin surface. Eight healthy subjects (22.4 +/-1.0 years) were passively heated by lower-leg immersion in a hot water bath of 42 degrees C for 50 min in an ambient temperature of 28 degrees C and relative humidity of 50%. The internal temperature (Tor) thresholds of sweat rate and index of sweat ion concentration were almost similar. Concomitant onset for the index of sweat ion concentration and sweat rate occurred but two types of linear regression lines were identified in the relationship between the index of sweat ion concentration and sweat rate at a boundary sweat rate value of 0.30 +/- 0.08 mg cm(-2) min(-1). The slope of the regression line at low levels of sweat (slope 0.02 +/- 0.01 V mg(-1) cm(-2) min(-1)) was significantly gradual compared with that at moderate levels of sweat (slope 0.30 +/- 0.08 V mg(-1) cm(-2) min(-1)) (P<0.05). These results suggest that at low levels of sweat the index of sweat ion concentration responds gradually with respect to sweat rate, which may be due to the ion reabsorption capacity of the sweat duct, and then the index of sweat ion concentration increased steeply with sweat rate.

  15. A new method of sweat testing: the CF Quantum®sweat test.

    Science.gov (United States)

    Rock, Michael J; Makholm, Linda; Eickhoff, Jens

    2014-09-01

    Conventional methods of sweat testing are time consuming and have many steps that can and do lead to errors. This study compares conventional sweat testing to a new quantitative method, the CF Quantum® (CFQT) sweat test. This study tests the diagnostic accuracy and analytic validity of the CFQT. Previously diagnosed CF patients and patients who required a sweat test for clinical indications were invited to have the CFQT test performed. Both conventional sweat testing and the CFQT were performed bilaterally on the same day. Pairs of data from each test are plotted as a correlation graph and Bland-Altman plot. Sensitivity and specificity were calculated as well as the means and coefficient of variation by test and by extremity. After completing the study, subjects or their parents were asked for their preference of the CFQT and conventional sweat testing. The correlation coefficient between the CFQT and conventional sweat testing was 0.98 (95% confidence interval: 0.97-0.99). The sensitivity and specificity of the CFQT in diagnosing CF was 100% (95% confidence interval: 94-100%) and 96% (95% confidence interval: 89-99%), respectively. In one center in this three center multicenter study, there were higher sweat chloride values in patients with CF and also more tests that were invalid due to discrepant values between the two extremities. The percentage of invalid tests was higher in the CFQT method (16.5%) compared to conventional sweat testing (3.8%) (p sweat chloride determination. This technology requires further refinement to improve the analytic accuracy at higher sweat chloride values and to decrease the number of invalid tests. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  16. The counterintuitive impact of separator-electrolyte combinations on the cycle life of graphite-silicon composite electrodes

    Science.gov (United States)

    Schott, Tiphaine; Gómez-Cámer, Juan Luis; Bünzli, Christa; Novák, Petr; Trabesinger, Sigita

    2017-03-01

    Thin polymeric membranes such as Celgard are commonly used as separators in Li-ion batteries to ensure high volumetric energy density. Independently, for silicon-based electrodes fluoroethylene carbonate (FEC) is often added to the electrolyte to improve the cycling stability of the cell. Here we demonstrate that, counterintuitively, this separator-electrolyte combination negatively affects the performance of graphite-Si electrodes in half-cells. In a statistical evaluation of the cycling behavior of C-Si electrode cells with various separators and either with or without FEC addition, we show that by improving the solid electrolyte interphase on the silicon particles, FEC addition leads to inhomogeneous current distribution in the electrodes, therefore favoring lithium dendrite growth and leading to irreversible failure with Celgard. In contrast, self-recovery is observed with simple glass-fiber separators. Without FEC, neither dendrites nor failure are observed, but cells with Celgard suffer from poorer electrochemical performance, due to clogging by the thick polymeric layer formed using standard electrolytes, than cells with thicker and hydrophilic separators.

  17. Sweating the small stuff: Glycoproteins in human sweat and their unexplored potential for microbial adhesion.

    Science.gov (United States)

    Peterson, Robyn A; Gueniche, Audrey; Adam de Beaumais, Ségolène; Breton, Lionel; Dalko-Csiba, Maria; Packer, Nicolle H

    2016-03-01

    There is increasing evidence that secretory fluids such as tears, saliva and milk play an important role in protecting the human body from infection via a washing mechanism involving glycan-mediated adhesion of potential pathogens to secretory glycoproteins. Interaction of sweat with bacteria is well established as the cause of sweat-associated malodor. However, the role of sweat glycoproteins in microbial attachment has received little, if any, research interest in the past. In this review, we demonstrate how recent published studies involving high-throughput proteomic analysis have inadvertently, and fortuitously, exposed an abundance of glycoproteins in sweat, many of which have also been identified in other secretory fluids. We bring together research demonstrating microbial adhesion to these secretory glycoproteins in tears, saliva and milk and suggest a similar role of the sweat glycoproteins in mediating microbial attachment to sweat and/or skin. The contribution of glycan-mediated microbial adhesion to sweat glycoproteins, and the associated impact on sweat derived malodor and pathogenic skin infections are unchartered new research areas that we are beginning to explore. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Normative data for regional sweat sodium concentration and whole-body sweating rate in athletes.

    Science.gov (United States)

    Baker, Lindsay B; Barnes, Kelly A; Anderson, Melissa L; Passe, Dennis H; Stofan, John R

    2016-01-01

    The purpose of this study was to establish normative data for regional sweat sodium concentration ([Na+]) and whole-body sweating rate in athletes. Data from 506 athletes (367 adults, 139 youth; 404 male, 102 female) were compiled from observational athlete testing for a retrospective analysis. The participants were skill/team-sport (including American football, baseball, basketball, soccer and tennis) and endurance (including cycling, running and triathlon) athletes exercising in cool to hot environmental conditions (15-50 °C) during training or competition in the laboratory or field. A standardised regional absorbent patch technique was used to determine sweat [Na+] on the dorsal mid-forearm. Whole-body sweat [Na+] was predicted using a published regression equation (y = 0.57x+11.05). Whole-body sweating rate was calculated from pre- to post-exercise change in body mass, corrected for fluid/food intake (ad libitum) and urine output. Data are expressed as mean ± SD (range). Forearm sweat [Na+] and predicted whole-body sweat [Na+] were 43.6 ± 18.2 (12.6-104.8) mmol · L(-1) and 35.9 ± 10.4 (18.2-70.8) mmol · L(-1), respectively. Absolute and relative whole-body sweating rates were 1.21 ± 0.68 (0.26-5.73) L · h(-1) and 15.3 ± 6.8 (3.3-69.7) ml · kg(-1) · h(-1), respectively. This retrospective analysis provides normative data for athletes' forearm and predicted whole-body sweat [Na+] as well as absolute and relative whole-body sweating rate across a range of sports and environmental conditions.

  19. Ionic Liquid-Sulfolane Composite Electrolytes for High-Performance and Stable Dye-Sensitized Solar Cells

    OpenAIRE

    Marsalek Magdalena; Duriaux Arendse Francine; Decoppet Jean-David; Babkair Saeed Salem; Ansari Azhar Ahmad; Habib Sami S.; Wang Mingkui; Zakeeruddin Shaik M.; Graätzel Michael

    2014-01-01

    Ionic liquid electrolytes are prepared using sulfolane as a plasticizer for eutectic melts to realize highly stable and effi ciently performing dye sensi tized solar cells (DSCs) in hot climate conditions. Variations in the viscosity of the formulations with sulfolane content are measured and performance in DSCs is investigated using the ruthenium dye C106 as a sensitizer. A power conversion effi ciency (PCE) of 8.2 is achieved under standard reporting con ditions. Apart from lowering the vis...

  20. Development of a method for enhancing metabolomics coverage of human sweat by gas chromatography-mass spectrometry in high resolution mode.

    Science.gov (United States)

    Delgado-Povedano, M M; Calderón-Santiago, M; Priego-Capote, F; Luque de Castro, M D

    2016-01-28

    Sweat has recently gained popularity as clinical sample in metabolomics analysis as it is a non-invasive biofluid the composition of which could be modified by certain pathologies, as is the case with cystic fibrosis that increases chloride levels in sweat. However, the whole composition of sweat is still unknown and there is a lack of analytical strategies for sweat analysis. The aim of the present study was to develop and validate a method for metabolomic analysis of human sweat by gas chromatography-time of flight/mass spectrometry (GC-TOF/MS) in high resolution mode. Thus, different sample preparation strategies were compared to check their effect on the profile of sweat metabolites. Sixty-six compounds were tentatively identified by the obtained MS information. Amino acids, dicarboxylic acids and other interesting metabolites such as myo-inositol and urocanic acid were identified. Among the tested protocols, methyoxiamination plus silylation after deproteinization was the most suited option to obtain a representative snapshot of sweat metabolome. The intra-day repeatability of the method ranged from 0.60 to 16.99% and the inter-day repeatability from 2.75 to 31.25%. As most of the identified metabolites are involved in key biochemical pathways, this study opens new possibilities to the use of sweat as a source of metabolite biomarkers of specific disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Highly abundant defense proteins in human sweat as revealed by targeted proteomics and label-free quantification mass spectrometry.

    Science.gov (United States)

    Csősz, É; Emri, G; Kalló, G; Tsaprailis, G; Tőzsér, J

    2015-10-01

    The healthy human skin with its effective antimicrobial defense system forms an efficient barrier against invading pathogens. There is evidence suggesting that the composition of this chemical barrier varies between diseases, making the easily collected sweat an ideal candidate for biomarker discoveries. Our aim was to provide information about the normal composition of the sweat, and to study the chemical barrier found at the surface of skin. Sweat samples from healthy individuals were collected during sauna bathing, and the global protein panel was analysed by label-free mass spectrometry. SRM-based targeted proteomic methods were designed and stable isotope labelled reference peptides were used for method validation. Ninety-five sweat proteins were identified, 20 of them were novel proteins. It was shown that dermcidin is the most abundant sweat protein, and along with apolipoprotein D, clusterin, prolactin-inducible protein and serum albumin, they make up 91% of secreted sweat proteins. The roles of these highly abundant proteins were reviewed; all of which have protective functions, highlighting the importance of sweat glands in composing the first line of innate immune defense system, and maintaining the epidermal barrier integrity. Our findings with regard to the proteins forming the chemical barrier of the skin as determined by label-free quantification and targeted proteomics methods are in accordance with previous studies, and can be further used as a starting point for non-invasive sweat biomarker research. © 2015 European Academy of Dermatology and Venereology.

  2. Real-time sweat analysis via alternating current conductivity of artificial and human sweat

    Science.gov (United States)

    Liu, Gengchen; Alomari, Mahmoud; Sahin, Bunyamin; Snelgrove, Samuel E.; Edwards, Jeffrey; Mellinger, Axel; Kaya, Tolga

    2015-03-01

    Dehydration is one of the most profound physiological challenges that significantly affects athletes and soldiers if not detected early. Recently, a few groups have focused on dehydration detection using sweat as the main biomarker. Although there are some proposed devices, the electrical and chemical characteristics of sweat have yet to be incorporated into the validations. In this work, we have developed a simple test setup to analyze artificial sweat that is comprised the main components of human sweat. We provide theoretical and experimental details on the electrical and chemical behavior of the artificial sweat for various concentration values within a temperature range of 5 °C to 50 °C. We have also developed an efficient sweat collecting and detection system based on 3D printing. Human studies were conducted and this particular protocol has shown that dehydration starts to take effect as early as 40 min into the physical activity if there is no fluid intake during the exercise. We believe that our device will lead to developing viable real-time sweat analysis systems.

  3. Biological variability of the sweat chloride in diagnostic sweat tests: A retrospective analysis.

    Science.gov (United States)

    Vermeulen, F; Lebecque, P; De Boeck, K; Leal, T

    2017-01-01

    The sweat test is the current gold standard for the diagnosis of cystic fibrosis (CF). CF is unlikely when sweat chloride (Cl sw ) is lower than 30mmol/L, Cl sw >60 is suggestive of CF, with intermediate values between 30 and 60mmol/L. To correctly interpret a sweat chloride value, the biological variability of the sweat chloride has to be known. Sweat tests performed in two centers using the classic Gibson and Cooke method were retrospectively reviewed (n=5904). Within test variability of Cl sw was measured by comparing results from right and left arm collected on the same day. Between test variability was calculated from subjects with sweat tests performed on more than one occasion. Within test variability of Cl sw calculated in 1022 subjects was low with differences between -3.2 (p5) and +3.6mmol/L (p95). Results from left and right arm were classified differently in only 3 subjects. Between test variability of Cl sw in 197 subjects was larger, with differences between -18.2mmol/L (p5) and +14.1mmol/L (p95) between repeat tests. Changes in diagnostic conclusion were seen in 55/197 subjects, the most frequent being changing from indeterminate to 'CF unlikely' range (48/102). Variability of sweat chloride is substantial, with frequent changes in diagnostic conclusion, especially in the intermediate range. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  4. Efficient sweat reduction of three different antiperspirant application forms during stress-induced sweating.

    Science.gov (United States)

    Schmidt-Rose, T; Lehmbeck, F; Bürger, A; Windisch, B; Keyhani, R; Max, H

    2013-12-01

    Stress sweating can occur in everyday situations independently of thermally-induced perspiration. It is triggered by emotionally challenging situations and leads to underarm wetness and a characteristic unpleasant malodor. In this study, we aimed to determine the long-term efficacy of three unperfumed antiperspirant (AP) formulas for different application forms (roll-on, stick, aerosol) against stress-induced sweating and malodor formation. We utilized the widely accepted Trier Social Stress Test (TSST) to induce psychosocial stress in female and male volunteers (18 - 40 years) and determined physiological stress parameters. To additionally assess the efficacy of the test AP roll-on against thermally-induced sweating, a hot room study was performed. Increasing heart rates and an augmentation of saliva cortisol levels during the TSST indicated a substantial stress reaction which was paralleled by a pronounced sweat production in the untreated axillae of both males and females. Forty-eight hours after application, all three test APs significantly decreased the amount of sweat in the treated axillae independent of gender. With respect to AP effects on malodor production, trained sniffers assessed sweat samples collected during the TSST from the untreated axillae as significantly more malodorous than comparable samples from the AP-treated axillae. Also, independent of gender the test AP roll-on significantly decreased the thermally-induced sweat in the AP-treated axilla. We show for the first time a highly effective reduction of emotionally-induced axillary sweating and malodor production for three different application forms 48 h after the last product use. The specially developed roll-on, stick, and aerosol AP provide long-term protection against stress-induced sweat which is of high relevance in everyday life. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  5. Excretion of Δ9-Tetrahydrocannabinol in Sweat

    Science.gov (United States)

    Huestis, Marilyn A.; Scheidweiler, Karl B.; Saito, Takeshi; Fortner, Neil; Abraham, Tsadik; Gustafson, Richard A.; Smith, Michael L.

    2008-01-01

    Sweat testing is a noninvasive technique for monitoring drug exposure over a 7-day period in treatment, criminal justice, and employment settings. We evaluated Δ9-tetrahydrocannabinol (THC) excretion in 11 daily cannabis users after cessation of drug use. PharmChek® sweat patches worn for 7 days were analyzed for THC by gas chromatography-mass spectrometry (GC/MS). The limit of quantification (LOQ) for the method was 0.4 ng THC/patch. Sweat patches worn the first week of continuously monitored abstinence had THC above the United States Substance Abuse Mental Health Services Administration’s proposed cutoff concentration for federal workplace testing of 1 ng THC/patch. Mean ± S.E.M. THC concentrations were 3.85 ± 0.86 ng THC/patch. Eight of 11 subjects had negative patches the second week and one produced THC positive patches for four weeks of monitored abstinence. We also tested daily and weekly sweat patches from 7 subjects who were administered oral doses of up to 14.8 mg THC/day for five consecutive days. In this oral THC administration study, no daily or weekly patches had THC above the LOQ; concurrent plasma THC concentrations were all less than 6.1 μg/L. In conclusion, using proposed federal cutoff concentrations, most daily cannabis users will have a positive sweat patch in the first week after ceasing drug use and a negative patch after subsequent weeks, although patches may remain positive for four weeks or more. Oral ingestion of up to 14.8 mg THC daily does not produce a THC positive sweat patch test. PMID:17481836

  6. Surface contamination artificially elevates initial sweat mineral concentrations

    Science.gov (United States)

    During exercise in the heat, sweat is initially concentrated in minerals, but serial sweat samples appear more dilute. Possible causes include reduced dermal mineral concentrations or flushing of surface contamination. PURPOSE: To simultaneously sample mineral concentrations in transdermal fluid (T...

  7. Cannabis Use Surveillance by Sweat Analysis.

    Science.gov (United States)

    Gambelunghe, Cristiana; Fucci, Nadia; Aroni, Kyriaki; Bacci, Mauro; Marcelli, Antonio; Rossi, Riccardo

    2016-10-01

    Sweat testing, an alternative matrix for establishing drug abuse, offers additional benefits to the more common biological samples. The authors developed a procedure using gas chromatography-mass spectrometry to test for Δ9-tetrahydrocannabinol, 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid, cannabinol (CBN), and cannabidiol (CBD) in a sweat patch. The results were compared with urine and hair sample results. Urine, hair, and sweat samples were simultaneously collected from 12 patients who were involved, respectively, in forensic case and monitoring abuse. Selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), recovery, intraday and interday imprecision, and inaccuracy of the quantification procedure were validated. LODs in hair were 0.05 ng/mg for Δ9-tetrahydrocannabinol, CBN, and CBD, and 0.005 ng/mg for 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid. The LOD for sweat was 0.30 ng/patch for all substances. The LOQ in hair was 0.1 ng/mg for Δ9-tetrahydrocannabinol, CBN, and CBD, and 0.01 ng/mg for 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid. The LOQ was 0.4 ng/patch in sweat for each analyte. Cannabinoid in urine was determined by means of immunochemical screening (cutoff 11-nor-Δ-tetrahydrocannabinol-9-carboxylic acid 50 ng/mL). All subjects tested positive for 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid and Δ9-tetrahydrocannabinol in urine and hair. In sweat samples, Δ9-tetrahydrocannabinol was found in all patches (0.4-2.0 ng/patch); 6 cases were positive for CBN (0.4-0.5 ng/patch) and 3 for CBD (0.4-0.6 ng/patch); 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid was never detected in patches. Present sweat analysis results integrated the information from hair and urine and showed that sweat analysis is a suitable, noninvasive method for monitoring compliance with rehabilitation therapy and for detecting recent cumulative use of cannabinoids.

  8. Prediction of Water Requirements to Replace Sweat Losses

    Science.gov (United States)

    2010-10-01

    RTO-MP-HFM-202 P6 - 1 Prediction of Water Requirements to Replace Sweat Losses Samuel N. Cheuvront, Ph.D., Richard R. Gonzalez, Ph.D...3. DATES COVERED - 4. TITLE AND SUBTITLE Prediction of Water Requirements to Replace Sweat Losses 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...Prediction of Water Requirements to Replace Sweat Losses P6 - 2 RTO-MP-HFM-202 Conclusion OSEC and PW provide for more accurate sweat

  9. Polymer composite electrolytes having core-shell silica fillers with anion-trapping boron moiety in the shell layer for all-solid-state lithium-ion batteries.

    Science.gov (United States)

    Shim, Jimin; Kim, Dong-Gyun; Kim, Hee Joong; Lee, Jin Hong; Lee, Jong-Chan

    2015-04-15

    Core-shell silica particles with ion-conducting poly(ethylene glycol) and anion-trapping boron moiety in the shell layer were prepared to be used as fillers for polymer composite electrolytes based on organic/inorganic hybrid branched copolymer as polymer matrix for all-solid-state lithium-ion battery applications. The core-shell silica particles were found to improve mechanical strength and thermal stability of the polymer matrix and poly(ethylene glycol) and boron moiety in the shell layer increase compatibility between filler and polymer matrix. Furthermore, boron moiety in the shell layer increases both ionic conductivity and lithium transference number of the polymer matrix because lithium salt can be more easily dissociated by the anion-trapping boron. Interfacial compatibility with lithium metal anode is also improved because well-dispersed silica particles serve as protective layer against interfacial side reactions. As a result, all-solid-state battery performance was found to be enhanced when the copolymer having core-shell silica particles with the boron moiety was used as solid polymer electrolyte.

  10. In situ electrochemical polymerization of a nanorod-PANI-Graphene composite in a reverse micelle electrolyte and its application in a supercapacitor.

    Science.gov (United States)

    Hu, Liwen; Tu, Jiguo; Jiao, Shuqiang; Hou, Jungang; Zhu, Hongmin; Fray, Derek J

    2012-12-05

    Highly porous nanorod-PANI-Graphene composite films were prepared by in situ electrochemical polymerization onto an ITO substrate in a reverse micelle electrolyte. The morphology and microstructure of the composite films were analyzed by using a field emission scanning electron microscope. It was observed that the films were highly porous and the nanorod PANI films were inserted by graphene nanosheets. This indicated that a good conductive network between PANI nanorods and graphene sheets was formed. Further electrochemical tests involved cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) in 1 mol L(-1) HClO(4) solution. The results showed that the composite film had a favorable capacitance with a high electron transfer rate and low resistance. The highest specific capacitance that could be achieved was as high as 878.57 F g(-1) with the charge loading of 500 mC at a current density of 1 A g(-1). The GCD at different charge loadings showed good cycle stability with a low fading rate of specific capacitance after 1000 cycles. The results demonstrated that the nanorod-PANI-Graphene composite was proved to be of great potential as an electrode material for supercapacitors.

  11. Electrophoretic deposition of 9-YSZ solid electrolyte on Ni- YSZ composite; Estudos de deposicao eletroforetica de ceramicas de 9-YSZ sobre Ni-YSZ

    Energy Technology Data Exchange (ETDEWEB)

    Santos, F.S.; Yoshito, W.K.; Lazar, D.R.R.; Ussui, V., E-mail: vussui@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais

    2010-07-01

    9-YSZ ceramic and Ni-YSZ metal/ceramic composite are the more commonly used materials for the fabrication of solid oxide fuel cell electrolyte and anode, respectively. The main challenges for these applications are the forming of both materials as superposed double thin layers. In the present work ceramic powder of 9- YSZ was synthesized by a coprecipitation technique and the Ni O-YSZ composite by a combustion technique. The later was formed by uniaxial pressing as cylindrical pellets of 15 mm diameter. Thin ceramic layers of 9-YSZ were deposited on composite pellets from a suspension with 10% solid content by an Electrophoretic Deposition technique. Applied voltage varied in the range of 30 to 200 V and deposition time from 15 to 90 seconds, evaluating the deposited mass, porosity on the interface and adhesion of layers. Resulted ceramics were characterized by X-ray diffraction and were observed in a scanning electron microscope. Results showed that deposited layers are thin ({approx}20{mu}m), dense and have good adhesion on the surface of composite substrate. (author)

  12. A portable optical human sweat sensor

    Science.gov (United States)

    Al-omari, Mahmoud; Liu, Gengchen; Mueller, Anja; Mock, Adam; Ghosh, Ruby N.; Smith, Kyle; Kaya, Tolga

    2014-11-01

    We describe the use of HNQ (2-hydroxy-1,4-naphthoquinone or Lawsone) as a potential sweat sensor material to detect the hydration levels of human beings. We have conducted optical measurements using both artificial and human sweat to validate our approach. We have determined that the dominant compound that affects HNQ absorbance in artificial sweat is sodium. The presence of lactate decreases the reactivity of HNQ while urea promotes more interactions of sodium and potassium ions with HNQ. The interactions between the hydroxyl group of HNQ and the artificial sweat components (salts, lactic acid, and urea) were investigated comprehensively. We have also proposed and developed a portable diode laser absorption sensor system that converts the absorbance at a particular wavelength range (at 455 ± 5 nm, where HNQ has an absorbance peak) into light intensity measurements via a photocell. The absorbance intensity values obtained from our portable sensor system agrees within 10.4% with measurements from a laboratory based ultraviolet-visible spectrometer. Findings of this research will provide significant information for researchers who are focusing on real-time, in-situ hydration level detection.

  13. Effects of dietary protein and energy levels on digestive enzyme activities and electrolyte composition in the small intestinal fluid of geese.

    Science.gov (United States)

    Yang, Jing; Yang, Lin; Wang, Yongchang; Zhai, Shuangshuang; Wang, Shenshen; Yang, Zhipeng; Wang, Wence

    2017-02-01

    The present study was conducted to evaluate the effects of dietary protein and energy levels on digestive enzymes and electrolyte composition in jejunum of geese. A 3×3 factorial and completely randomized design was adopted with three protein levels and three energy levels. The experiment included four replicates for each treatment, and three geese for each replicate. Isovolumetric supernate from centrifugal jejuna fluid were mixed in each replicate. Activities of digestive enzymes and ions were analyzed. The results showed trypsin and chymotrypsin activities were significantly increased with increasing of dietary protein and energy levels (Pelectrolytes in the small intestine adapted to the protein and energy levels. The activities of protease, rather than amylase and cellulase were induced with increasing of protein and energy levels. The imbalance of positive and negative ions was possibly adjusted by the fluctuant concentrations of K(+) , Cl(-) and Ca(2+) for maintaining normal physiological function. © 2016 Japanese Society of Animal Science.

  14. Electrolyte Racers

    Science.gov (United States)

    Kellie, Shawn; Kellie, Tonya; Corbin-Tipton, Elizabeth

    2006-01-01

    A fast way to teach investigative skills in science is to tie them to NASCAR using Hot Wheels Formula Fuelers Race Cars. These inexpensive toy cars travel different distances based on the strength of the "electrolyte" (a substance that conducts electricity when dissolved in water) in their "fuel" tanks. Advertisements for these race cars urge kids…

  15. Lead-Free Sn-Ce-O Composite Coating on Cu Produced by Pulse Electrodeposition from an Aqueous Acidic Sulfate Electrolyte

    Science.gov (United States)

    Sharma, Ashutosh; Das, Karabi; Das, Siddhartha

    2017-10-01

    Pulse-electrodeposited Sn-Ce-O composite solder coatings were synthesized on a Cu substrate from an aqueous acidic solution containing stannous sulfate (SnSO4·3H2O), sulfuric acid (H2SO4), and Triton X-100 as an additive. The codeposition was achieved by adding nano-cerium oxide powder in varying concentrations from 5 g/L to 20 g/L into the electrolytic bath. Microstructural characterization was carried out using x-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy. The XRD analysis showed that the deposits consist mainly of tetragonal β (Sn) with reduced cerium oxide species. The composite coatings thus obtained exhibit a smaller grain size, possess higher microhardness, and a lower melting point than the monolithic Sn coating. The electrical resistivity of the developed composites increases, however, but lies within the permissible limits for current lead-free solder applications. Also, an optimum balance of properties in terms of microhardness, adhesion, melting point and resistivity can be obtained with 0.9 wt.% cerium oxide in the Sn matrix, which enables potential applications in solder joints and packaging.

  16. Optimization study for metabolomics analysis of human sweat by liquid chromatography-tandem mass spectrometry in high resolution mode.

    Science.gov (United States)

    Calderón-Santiago, M; Priego-Capote, F; Jurado-Gámez, B; Luque de Castro, M D

    2014-03-14

    Sweat has recently gained popularity as a potential tool for diagnostics and biomarker monitoring as it is a non-invasive biofluid the composition of which could be modified by certain pathologies, as is the case with cystic fibrosis, which increases chloride levels in sweat. The aim of the present study was to develop an analytical method for analysis of human sweat by liquid chromatography-mass spectrometry (LC-Q-TOF MS/MS) in high resolution mode. Thus, different sample preparation strategies and different chromatographic modes (HILIC and C18 reverse modes) were compared to check their effect on the profile of sweat metabolites. Forty-one compounds were identified by the MS/MS information obtained with a mass tolerance window below 4 ppm. Amino acids, dicarboxylic acids and other interesting metabolites such as inosine, choline, uric acid and tyramine were identified. Among the tested protocols, direct analysis after dilution was a suited option to obtain a representative snapshot of sweat metabolome. In addition, sample clean up by C18 SpinColumn SPE cartridges improved the sensitivity of most identified compounds and reduced the number of interferents. As most of the identified metabolites are involved in key biochemical pathways, this study opens new possibilities to the use of sweat as a source of metabolite biomarkers of specific disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Skin Tattoos Alter Sweat Rate and Na+ Concentration.

    Science.gov (United States)

    Luetkemeier, Maurie Joe; Hanisko, Joseph Michael; Aho, Kyle Mathiew

    2017-07-01

    The popularity of tattoos has increased tremendously in the last 10 yr particularly among athletes and military personnel. The tattooing process involves permanently depositing ink under the skin at a similar depth as eccrine sweat glands (3-5 mm). The purpose of this study was to compare the sweat rate and sweat Na concentration of tattooed versus nontattooed skin. The participants were 10 healthy men (age = 21 ± 1 yr), all with a unilateral tattoo covering a circular area at least 5.2 cm. Sweat was stimulated by iontophoresis using agar gel disks impregnated with 0.5% pilocarpine nitrate. The nontattooed skin was located contralateral to the position of the tattooed skin. The disks used to collect sweat were composed of Tygon® tubing wound into a spiral so that the sweat was pulled into the tubing by capillary action. The sweat rate was determined by weighing the disk before and after sweat collection. The sweat Na concentration was determined by flame photometry. The mean sweat rate from tattooed skin was significantly less than nontattooed skin (0.18 ± 0.15 vs 0.35 ± 0.25 mg·cm·min; P = 0.001). All 10 participants generated less sweat from tattooed skin than nontattooed skin and the effect size was -0.79. The mean sweat Na concentration from tattooed skin was significantly higher than nontattooed skin (69.1 ± 28.9 vs 42.6 ± 15.2 mmol·L; P = 0.02). Nine of 10 participants had higher sweat Na concentration from tattooed skin than nontattooed skin, and the effect size was 1.01. Tattooed skin generated less sweat and a higher Na concentration than nontattooed skin when stimulated by pilocarpine iontophoresis.

  18. Suppression of Lithium Dendrite Formation by Using LAGP-PEO (LiTFSI) Composite Solid Electrolyte and Lithium Metal Anode Modified by PEO (LiTFSI) in All-Solid-State Lithium Batteries.

    Science.gov (United States)

    Wang, Chunhua; Yang, Yifu; Liu, Xingjiang; Zhong, Hai; Xu, Han; Xu, Zhibin; Shao, Huixia; Ding, Fei

    2017-04-19

    The formation of lithium dendrites is suppressed using a Li1.5Al0.5Ge1.5(PO4)3-poly(ethylene oxide) (LAGP-PEO) composite solid electrolyte and a PEO (lithium bis(trifluoromethane)sulfonimide) [PEO (LiTFSI)]-modified lithium metal anode in all-solid-state lithium batteries. The effects on the anode performance based on the PEO content in the composite solid electrolyte and the molecular weight of PEO used to modify the Li anode are studied. The structure, surface morphology, and stability of the composite solid electrolyte are examined by X-ray diffraction spectroscopy, scanning electron microscopy, and electrochemical tests. Results show that the presence of a PEO-500000(LiTFSI) film on a Li anode results in good mechanical properties and satisfactory interface contact features. The film can also prevent Li from reacting with LAGP. Furthermore, the formation of lithium dendrites can be effectively inhibited as the composite solid electrolyte is combined with the PEO film on the Li anode. The ratio of PEO in the composite solid electrolyte can be reduced to a low level of 1 wt %. PEO remains stable even at a high potential of 5.12 V (vs Li/Li(+)). The assembled Li-PEO (LiTFSI)/LAGP-PEO/LiMn0.8Fe0.2PO4 all-solid-state cell can deliver an initial discharge capacity of 160.8 mAh g(-1) and exhibit good cycling stability and rate performance at 50 °C.

  19. 3D bioprinted extracellular matrix mimics facilitate directed differentiation of epithelial progenitors for sweat gland regeneration.

    Science.gov (United States)

    Huang, Sha; Yao, Bin; Xie, Jiangfan; Fu, Xiaobing

    2016-03-01

    Sweat glands perform a vital thermoregulatory function in mammals. Like other skin appendages, they originate from epidermal progenitors. However, they have low regenerative potential in response to injury, and whether adult epidermal progenitors could be specified to differentiate to a sweat gland cell lineage remains largely unexplored. We used bioprinting technology to create a functional in vitro cell-laden 3D extracellular matrix mimics (3D-ECM) with composite hydrogels based on gelatin and sodium alginate because of chemical and structural similarity to ECM components. To achieve specific cell differentiation, mouse plantar dermis and epidermal growth factor were synchronously incorporated into the 3D-ECM mimics to create an inductive niche for epidermal progenitor cells obtained from mice. The biological 3D construct could maintain cell viability, thereby facilitating cell spreading and matrix formation. In vitro data by immunofluorescence and gene expression assay of key cell-surface markers demonstrated that the bioprinted 3D-ECM could effectively create a restrictive niche for epidermal progenitors that ensures unilateral differentiation into sweat gland cells. Furthermore, direct delivery of bioprinted 3D-ECM into burned paws of mice resulted in functional restoration of sweat glands. This study represents the rational design to enhance the specific differentiation of epidermal lineages using 3D bioprinting and may have clinical and translational implications in regenerating sweat glands. Sweat gland regeneration after injury is of clinical importance but remains largely unsolved because of low regenerative potential and lack of a definite niche. Some studies have shown sweat gland regeneration with gene-based interventions or cell-based induction via embryonic components, but translation to clinic is challenging. The novelty and significance of the work lies in the fact that we design a 3D bioprinted extracellular matrix that provides the spatial

  20. Electrolyte Additives for Phosphoric Acid Fuel Cells

    DEFF Research Database (Denmark)

    Gang, Xiao; Hjuler, H.A.; Olsen, C.A.

    1993-01-01

    Electrochemical characteristics of a series of modified phosphoric acid electrolytes containing fluorinated car on compounds and silicone fluids as additives are presented. When used in phosphoric acid fuel cells, the modified electrolytes improve the performance due to the enhanced oxygen......, as a fuel-cell performance with the modified electrolytes. Specific conductivity measurements of some of the modified phosphoric acid electrolytes are reported. At a given temperature, the conductivity of the C4F9SO3K-modified electrolyte decreases with an increasing amount of the additive; the conductivity...... of the remains at the same value as the conductivity of the pure phosphoric acid. At a given composition, the conductivity of any modified electrolyte increases with temperature. We conclude that the improved cell performance for modified electrolytes is not due to any increase in conductivity....

  1. Construction of All-Solid-State Batteries based on a Sulfur-Graphene Composite and Li9.54 Si1.74 P1.44 S11.7 Cl0.3 Solid Electrolyte.

    Science.gov (United States)

    Xu, Ruochen; Wu, Zhang; Zhang, Shenzhao; Wang, Xiuli; Xia, Yan; Xia, Xinhui; Huang, Xiaohua; Tu, Jiangping

    2017-10-09

    Herein an effective way for construction of all-solid-state lithium-sulfur batteries (LSBs) with sulfur/reduced graphene oxide (rGO) and Li9.54 Si1.74 P1.44 S11.7 Cl0.3 solid electrolyte is reported. In the composite cathode, the Li9.54 Si1.74 P1.44 S11.7 Cl0.3 powder is homogeneously mixed with the S/rGO composite to enhance the ionic conductivity. Coupled with a metallic Li anode and solid electrolyte, the designed S/rGO-Li9.54 Si1.74 P1.44 S11.7 Cl0.3 composite cathode exhibits a high specific capacity and good cycling stability. A high initial discharge capacity of 969 mAh g(-1) is achieved at a current density of 80 mA g(-1) at room temperature and the cell retains a reversible capacity of over 827 mAh g(-1) after 60 cycles. The enhanced performance is attributed to the intimate contact between the S/rGO and Li9.54 Si1.74 P1.44 S11.7 Cl0.3 electrolyte, and high electrical conductivity of rGO and high ionic conductivity of the solid electrolyte. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Solid electrolytes

    Science.gov (United States)

    Abraham, Kuzhikalail M.; Alamgir, Mohamed

    1993-06-15

    This invention pertains to Li ion (Li.sup.+) conductive solid polymer electrolytes composed of solvates of Li salts immobilized (encapsulated) in a solid organic polymer matrix. In particular, this invention relates to solid polymer electrolytes derived by immobilizing complexes (solvates) formed between a Li salt such as LiAsF.sub.6, LiCF.sub.3 SO.sub.3 or LiClO.sub.4 and a mixture of aprotic organic solvents having high dielectric constants such as ethylene carbonate (EC) (dielectric constant=89.6) and propylene carbonate (PC) (dielectric constant=64.4) in a polymer matrix such as polyacrylonitrile, poly(tetraethylene glycol diacrylate), or poly(vinyl pyrrolidinone).

  3. Synthesis of 8YSZ-LSGM Composite Thick Film Ceramics for Solid Electrolyte From Nanopowder Utilizing Local Zircon Prepared Using Sol Gel Process

    Science.gov (United States)

    Syarif, Dani Gustaman; Soepriyanto, Syoni; Ismunandar, Korda, Akhmad

    2010-10-01

    Thick film ceramics of 8% mol Y2O3 doped-ZrO2 (8YSZ)-La0.8Sr0.2Ga0.2Mg0.8O3 (LSGM) composite for solid electrolyte have been synthesized from nanopowder. Concentration of LSGM was 0 and 10% weight. A paste for the thick films was made from 8YSZ nanopowder prepared using sol gel method and LSGM powder prepared by solid state reaction. Precursors for the 8YSZ nanopowder preparation were ZrOCl2ṡ8H2O derived from local zircon as byproduct of Tin processing at Bangka Island using caustic fussion method, and Y(NO3)3. The thick films were produced by screen printing technique on alumina substrates. The films were sintered at 1500° C for 2 hours in air. X-ray diffraction (XRD) data showed that the nanopowder of 8YSZ was well produced with broad peaks. The particle size of the 8YSZ powder was about 12 nm as calculated using Debye Scherrer method. The thick films of 8YSZ and 8YSZ-LSGM (90:10 in weight %) composite could be produced, however, the films still contain voids. The ionic conductance of the YSZ-10LSGM films was smaller than that of the YSZ films.

  4. Vitamin B12 deficiency causing night sweats.

    Science.gov (United States)

    Rehman, H U

    2014-11-01

    Vitamin B12 deficiency is common. It is known to cause a wide spectrum of neurological syndromes, including autonomic dysfunction. Three cases are discussed here in which drenching night sweats were thought to be caused by vitamin B12 deficiency. All three responded dramatically to vitamin B12 therapy. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  5. Genotoxicological assessment of two reactive dyes extracted from cotton fibres using artificial sweat.

    Science.gov (United States)

    Leme, Daniela Morais; de Oliveira, Gisele Augusto Rodrigues; Meireles, Gabriela; dos Santos, Tuane Cristina; Zanoni, Maria Valnice Boldrin; de Oliveira, Danielle Palma

    2014-02-01

    Human eyes have a remarkable ability to recognize hundreds of colour shades, which has stimulated the use of colorants, especially for clothing, but toxicological studies have shown that some textile dyes can be hazardous to human health. Under conditions of intense perspiration, dyes can migrate from coloured clothes and penetrate into human skin. Garments made from cotton fabrics are the most common clothing in tropical countries, due to their high temperatures. Aiming to identify safe textile dyes for dyeing cotton fabrics, the genotoxicity [in vitro Comet assay with normal human dermal fibroblasts (NHDF), Tail Intensity] and mutagenicity [Salmonella/microsome preincubation assay (30min), tester strains TA98, TA100, YG1041 and YG1042] of Reactive Blue 2 (RB2, CAS No. 12236-82-7, C.I. 61211) and Reactive Green 19 (RG19, CAS No. 61931-49-5, C.I. 205075) were evaluated both in the formulated form and as extracted from cotton fibres using different artificial sweats. Both the dyes could migrate from cotton fibres to sweat solutions, the sweat composition and pH being important factors during this extraction. However, the dye sweat solutions showed no genotoxic/mutagenic effects, whereas a weak mutagenic potential was detected by the Ames test for both dyes in their formulated form. These findings emphasize the relevance of textile dyes assessment under conditions that more closely resemble human exposure, in order to recognize any hazard. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Electrolyte salts for nonaqueous electrolytes

    Science.gov (United States)

    Amine, Khalil; Zhang, Zhengcheng; Chen, Zonghai

    2012-10-09

    Metal complex salts may be used in lithium ion batteries. Such metal complex salts not only perform as an electrolyte salt in a lithium ion batteries with high solubility and conductivity, but also can act as redox shuttles that provide overcharge protection of individual cells in a battery pack and/or as electrolyte additives to provide other mechanisms to provide overcharge protection to lithium ion batteries. The metal complex salts have at least one aromatic ring. The aromatic moiety may be reversibly oxidized/reduced at a potential slightly higher than the working potential of the positive electrode in the lithium ion battery. The metal complex salts may also be known as overcharge protection salts.

  7. Solid polymer electrolyte water electrolyser based on Nafion-TiO{sub 2} composite membrane for high temperature operation

    Energy Technology Data Exchange (ETDEWEB)

    Baglio, V.; Antonucci, V.; Arico, A.S. [CNR-ITAE, Messina (Italy); Matteucci, F.; Martina, F.; Zama, I. [Tozzi Renewable Energy SpA, Mezzano (Italy); Ciccarella, G. [National Nanotechnology Laboratory (NNL) of INFM-CNR, Distretto Tecnologico ISUFI, Innovazione, Universita del Salento, Lecce (Italy); Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Queretaro Sanfandila (Mexico); Ornelas, R.

    2009-06-15

    A composite Nafion-TiO{sub 2} membrane was manufactured by a recast procedure, using an in-house prepared TiO{sub 2}. This membrane has shown promising properties for high temperature operation in an SPE electrolyser allowing to achieve higher performance with respect to a commercial Nafion 115 membrane. This effect is mainly due to the water retention properties of the TiO{sub 2} filler. A promising increase in electrical efficiency was recorded at low current densities for the composite membrane-based SPE electrolyser at high temperature compared to conventional membrane-based devices. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  8. Perda de eletrólitos durante uma competição de duatlo terrestre no calor Electrolyte losses during a land based duatlhon competition in the heat

    Directory of Open Access Journals (Sweden)

    Geórgia Franco Becker

    2011-06-01

    Full Text Available Eventos esportivos prolongados, como o duatlo (6 km corrida, 26 km ciclismo e 4 km corrida podem levar o atleta a um desequilíbrio hidroeletrolítico, devido a perdas elevadas de suor, em especial se realizados no calor. O presente estudo avaliou as perdas de sódio (Na+, potássio (K+ e cloreto (Cl- durante uma competição de duatlo realizada no calor (31,2 °C e 51% de umidade relativa do ar, analisando a composição do suor e os níveis sanguíneos destes eletrólitos. Doze atletas fizeram parte deste estudo. Coletas de sangue foram realizadas antes e após a competição, e o suor foi coletado utilizando-se adesivos específicos. O tempo médio para completar a competição foi de 85,0 ± 6,57 min. O percentual de desidratação foi 3,0 ± 0,92%. A reposição de líquidos perdidos durante a competição foi 31 ± 18,7%. A taxa de sudorese foi 1,86 ± 0,56 L•h-1. A concentração de Na+, K+ e Cl- no suor foi 71 ± 26,05 mmol•L-1, 5,43 ± 1,98 mmol•L-1 e 58,93 ± 25,99 mmol•L¹, respectivamente. A perda total de Na+, K+ e Cl- no suor foi 132,11 ± 62,82 mmol, 10,09 ± 5,01 mmol e 109,75 ± 58,49 mmol, respectivamente. Em conclusão, os atletas não ingeriram líquido suficiente para repor o volume de fluidos perdido. Além disto, os participantes apresentaram elevada taxa de sudorese acompanhada de perdas de Na+, K+ e Cl-. Apesar disso, não ocorreram alterações nas concentrações de eletrólitos séricos.Prolonged sports events such as duathlon (6 km running, 26 km cycling and 4 km running, may lead the athlete to a fluid and electrolyte imbalance, due to high sweat rates, especially in a hot environment. The present study evaluated sodium (Na+, potassium (K+ and chloride (Cl- losses during a duathlon competition performed in the heat (31,2 ºC and 51% relative humidity, analyzing the sweat composition and blood levels of these electrolytes. Twelve athletes took part in this study. Blood samples were obtained pre- and post

  9. Quantification of sweat gland volume and innervation in neuropathy: Correlation with thermoregulatory sweat testing.

    Science.gov (United States)

    Loavenbruck, Adam; Wendelschaefer-Crabbe, Gwen; Sandroni, Paola; Kennedy, William R

    2014-10-01

    No study has correlated thermoregulatory sweat testing (TST) with histopathologic study of sweat glands (SGs) and SG nerve fibers (SGNFs). We studied 10 neuropathy patients in whom anhidrosis was found by TST and 10 matched controls. Skin biopsies were taken from both anhidrotic and sweating skin and immunohistochemical staining was done for nerves and basement membrane. For each biopsy, total tissue volume, total SG volume, and total SGNF length were measured. SGNF length per biopsy volume, SG volume per biopsy volume (SG%), and SGNF length per SG volume were calculated. SGNF length per biopsy volume was reduced in anhidrotic site biopsies of patients compared with controls. SG% was decreased and SGNF length per SG volume increased in patients compared with controls. The results suggest a concomitant loss of SG volume and SGNF length in neuropathy, with greater loss of SGNFs in anhidrotic skin, possibly exceeding collateral reinnervation. Copyright © 2014 Wiley Periodicals, Inc.

  10. Surfactant-Assisted Perovskite Nanofillers Incorporated in Quaternized Poly (Vinyl Alcohol Composite Membrane as an Effective Hydroxide-Conducting Electrolyte

    Directory of Open Access Journals (Sweden)

    Selvaraj Rajesh Kumar

    2017-05-01

    Full Text Available Perovskite LaFeO3 nanofillers (0.1% are incorporated into a quaternized poly(vinyl alcohol (QPVA matrix for use as hydroxide-conducting membranes in direct alkaline methanol fuel cells (DAMFCs. The as-synthesized LaFeO3 nanofillers are amorphous and functionalized with cetyltrimethylammonium bromide (CTAB surfactant. The annealed LaFeO3 nanofillers are crystalline without CTAB. The QPVA/CTAB-coated LaFeO3 composite membrane shows a defect-free structure while the QPVA/annealed LaFeO3 film has voids at the interfaces between the soft polymer and rigid nanofillers. The QPVA/CTAB-coated LaFeO3 composite has lower methanol permeability and higher ionic conductivity than the pure QPVA and QPVA/annealed LaFeO3 films. We suggest that the CTAB-coated LaFeO3 provides three functions to the polymeric composite: increasing polymer free volume, ammonium group contributor, and plasticizer to enhance the interfacial compatibility. The composite containing CTAB-coated LaFeO3 results in superior cell performance. A maximum power density of 272 mW cm−2 is achieved, which is among the highest power outputs reported for DAMFCs in the literature.

  11. Quality of sweat test (ST) based on the proportion of sweat sodium (Na) and sweat chloride (Cl) as diagnostic parameter of cystic fibrosis: are we on the right way?

    Science.gov (United States)

    Faria, Alethéa Guimarães; Marson, Fernando Augusto Lima; Gomez, Carla Cristina de Souza; Ribeiro, Maria Ângela Gonçalves de Oliveira; Morais, Lucas Brioschi; Servidoni, Maria de Fátima; Bertuzzo, Carmen Sílvia; Sakano, Eulália; Goto, Maura; Paschoal, Ilma Aparecida; Pereira, Mônica Corso; Hessel, Gabriel; Levy, Carlos Emílio; Toro, Adyléia Aparecida Dalbo Contrera; Peixoto, Andressa Oliveira; Simões, Maria Cristina Ribeiro; Lomazi, Elizete Aparecida; Nogueira, Roberto José Negrão; Ribeiro, Antônio Fernando; Ribeiro, José Dirceu

    2016-10-26

    To assess the quality of sweat test (ST) based on the proportion of sweat sodium and sweat chloride as diagnostic parameter of cystic fibrosis (CF). A retrospective study of 5,721 sweat samples and subsequent descriptive analysis were carried out. The test was considered "of good quality" (correct) when: (i) sweat chloride was lower than 60 mEq/L, and sweat sodium was higher than sweat chloride; (ii) sweat chloride was higher than 60 mEq/L, and sweat sodium was lower than sweat chloride. The study included 5,692/5,721 sweat samples of ST which had been requested due to clinical presentations compatible with CF and/or neonatal screenings with altered immunoreactive trypsinogen values. Considering the proportion of sweat sodium and sweat chloride as ST quality parameter, the test was performed correctly in 5,023/5,692 (88.2 %) sweat samples. The sweat chloride test results were grouped into four reference ranges for chloride (i) chloride sweat weight (p = 0.416). However, there was a positive association with: (i) gender, (ii) results of ST (p sweat chloride/sodium ratio (p sweat chloride values (p = 0.047), (iii) subject's age at the time of the ST grouped by numerical order (p = 0.001). Considering that the quality of ST can be assessed by levels of sweat sodium and sweat chloride, an increasing number of low-quality tests could be observed in our sweat samples. The quality of the test was associated with important factors, such as gender, CF diagnosis, and subjects' age.

  12. CsH2PO4/NdPO4 Composites as Proton Conducting Electrolytes for Intermediate Temperature Fuel Cells

    DEFF Research Database (Denmark)

    Anfimova, Tatiana; Jensen, Annemette Hindhede; Christensen, Erik

    2015-01-01

    Composite proton conducting materials based on cesium dihydrogen phosphate and neodymium phosphate hydrate were prepared and investigated in terms of X-ray diffraction, thermogravimetry, conductivity, stability and fuel cell performance. At 150°C the conductivity was 1.8 × 10−6 S cm−1 for the pri......Composite proton conducting materials based on cesium dihydrogen phosphate and neodymium phosphate hydrate were prepared and investigated in terms of X-ray diffraction, thermogravimetry, conductivity, stability and fuel cell performance. At 150°C the conductivity was 1.8 × 10−6 S cm−1...... of the solid acid. The electromotive force, open circuit voltage and fuel cell performance were measured as demonstration of the material application....

  13. Morphological, mechanical and thermo-kinetic characterization of coal ash incorporated high performance PEO/PMMA thin film electrolyte composites

    Science.gov (United States)

    Sultana, Sabiha; Saleem Khan, Mohammad; Rehan, Imran; Rehan, Kamran; Amin, Noor-ul-; Humayun, Muhammad; Tabassum, Safia; Minhaz, Aaliya

    2017-11-01

    In the present work indigenous coal ash of Pakistan was used to prepare polymeric nanocomposites with Poly (ethylene oxide) (PEO)/Poly (methyl methacrylate) (PMMA)/lithium perchlorate (LiClO4). The coal ash was first characterized by various advanced spectroscopic techniques. The coal ash loading into the polymeric blend composites was considered by Thermo gravimetric/differential thermal analysis (TG/DTA), universal testing machine (UTM) and scanning electron microscopy (SEM)/energy dispersive x-rays (EDX) analysis. From TG/DTA data detailed kinetic analysis was performed. By applying various kinetic models, a range of kinetic parameters like ▵E, ▵G, ▵H, ▵S and A were successfully calculated for the first time for the studied system. Based upon aforementioned characterization it was established that coal ash incorporation into the polymeric blend composites improves its thermal and mechanical performance.

  14. The charge transport in polymeric gel electrolytes

    CERN Document Server

    Reiche, A

    2001-01-01

    The aim of the present thesis consisted in the study of the charge transport in gel electrolytes, which were obtained by photopolymerization of oligo(ethylene glycol) sub n -dimethacrylates with n=3, 9, and 23, and the survey of structure and property relations for the optimization of the electrolyte composition. The pressure dependence of the electric conductivity was measured. (HSI)

  15. Sweat conductivity: an accurate diagnostic test for cystic fibrosis?

    Science.gov (United States)

    Mattar, Ana Claudia Veras; Leone, Claudio; Rodrigues, Joaquim Carlos; Adde, Fabíola Villac

    2014-09-01

    Sweat chloride test is the gold standard test for cystic fibrosis (CF) diagnosis. Sweat conductivity is widely used although still considered a screening test. This was a prospective, cross-sectional, diagnostic research conducted at the laboratory of the Instituto da Criança of the Hospital das Clínicas, São Paulo, Brazil. Sweat chloride (quantitative pilocarpine iontophoresis) and sweat conductivity tests were simultaneously performed in patients referred for a sweat test between March 2007 and October 2008. Conductivity and chloride cut-off values used to rule out or diagnose CF were sweat chloride and conductivity values were 11 and 25 mmol/L in these populations, respectively. Twenty-four patients who had received a diagnosis of CF presented median sweat chloride and conductivity values of 87 and 103 mmol/L, respectively. Conductivity values above 90 mmol/L had 83.3% sensitivity, 99.7% specificity, 90.9% PPV and 99.4% NPV to diagnose CF. The best conductivity cut-off value to exclude CF was sweat conductivity test yielded a high degree of diagnostic accuracy and it showed good agreement with sweat chloride. We suggest that it should play a role as a diagnostic test for CF in the near future. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  16. Decreased sweating in seven patients with Laron syndrome

    DEFF Research Database (Denmark)

    Main, K M; Price, D A; Savage, M O

    1993-01-01

    Previous studies have shown that sweat secretion was reduced in patients with GH deficiency and increased during GH treatment, indicating an influence of GH on sweat gland function. Thus, patients with GH deficiency have impaired thermoregulation. We report on sweat secretion rates (SSRs) in seven......). These observations further supported the hypothesis that sweat gland function in humans is under the influence of the GH-insulin-like growth factor-I axis. It remains to be seen whether the decrease in SSR also leads to altered thermoregulation in patients with Laron syndrome....

  17. Optimal composition of fluid-replacement beverages.

    Science.gov (United States)

    Baker, Lindsay B; Jeukendrup, Asker E

    2014-04-01

    The objective of this article is to provide a review of the fundamental aspects of body fluid balance and the physiological consequences of water imbalances, as well as discuss considerations for the optimal composition of a fluid replacement beverage across a broad range of applications. Early pioneering research involving fluid replacement in persons suffering from diarrheal disease and in military, occupational, and athlete populations incurring exercise- and/or heat-induced sweat losses has provided much of the insight regarding basic principles on beverage palatability, voluntary fluid intake, fluid absorption, and fluid retention. We review this work and also discuss more recent advances in the understanding of fluid replacement as it applies to various populations (military, athletes, occupational, men, women, children, and older adults) and situations (pathophysiological factors, spaceflight, bed rest, long plane flights, heat stress, altitude/cold exposure, and recreational exercise). We discuss how beverage carbohydrate and electrolytes impact fluid replacement. We also discuss nutrients and compounds that are often included in fluid-replacement beverages to augment physiological functions unrelated to hydration, such as the provision of energy. The optimal composition of a fluid-replacement beverage depends upon the source of the fluid loss, whether from sweat, urine, respiration, or diarrhea/vomiting. It is also apparent that the optimal fluid-replacement beverage is one that is customized according to specific physiological needs, environmental conditions, desired benefits, and individual characteristics and taste preferences.

  18. Control of morphology and composition of self-organized zirconium titanate nanotubes formed in (NH{sub 4}){sub 2}SO{sub 4}/NH{sub 4}F electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Kouji [Department of Materials Science, Institute for Surface Science and Corrosion (LKO), University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen (Germany); Schmuki, Patrik [Department of Materials Science, Institute for Surface Science and Corrosion (LKO), University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen (Germany)]. E-mail: schmuki@ww.uni-erlangen.de

    2007-03-10

    We investigated the formation of self-organized zirconium titanate nanotubes by anodizing a Ti-35Zr alloy in 1 M (NH{sub 4}){sub 2}SO{sub 4} + 0.1-2.0 wt.% NH{sub 4}F electrolytes. The morphology and composition of the zirconium titanate nanotube are controlled by the applied electrochemical conditions. The outer diameter of nanotubes is controlled by the anodization potential in the range between 1 and 100 V (versus Ag/AgCl). Tubes with diameters from 14 to 470 nm can be grown. The nanotube length correlates with the anodic charge up to a length where significant dissolution of the nanotube layer is observed. The wall thickness, composition of the nanotubes and porosity of the nanotube layer are significantly affected by the fluoride ion concentration. The length limiting factor of the nanotube growth is found to be the diffusion of ionic species in the electrolyte.

  19. Electrolytes for Wide Operating Temperature Lithium-Ion Cells

    Science.gov (United States)

    Smart, Marshall C. (Inventor); Bugga, Ratnakumar V. (Inventor)

    2016-01-01

    Provided herein are electrolytes for lithium-ion electrochemical cells, electrochemical cells employing the electrolytes, methods of making the electrochemical cells and methods of using the electrochemical cells over a wide temperature range. Included are electrolyte compositions comprising a lithium salt, a cyclic carbonate, a non-cyclic carbonate, and a linear ester and optionally comprising one or more additives.

  20. Characteristics of sweating responses and peripheral sweat gland function during passive heating in sprinters.

    Science.gov (United States)

    Amano, Tatsuro; Koga, Shunsaku; Inoue, Yoshimitsu; Nishiyasu, Takeshi; Kondo, Narihiko

    2013-08-01

    The purpose of this study was to compare sweating function in sprinters who have trained for several years with untrained subjects and trained endurance runners. Two separate experiments were conducted. Nine sprinters, eight untrained men, and nine distance runners (VO2 max 50.9 ± 1.4, 38.2 ± 1.8, and 59.1 ± 1.2 mL/kg/min, respectively; P sprinters, 11 untrained men and nine distance runners (similar VO2 max levels compared with Experiment 1 in each group) had their sweat gland capacity assessed based on acetylcholine-induced sweating rate (SR) (Experiment 2). The slope of the mean non-glabrous SR plotted against change in mean body temperature during passive heating did not differ significantly between sprinters and untrained men (1.21 ± 0.10 and 0.97 ± 0.12 mg cm(-2)/min/°C, respectively); in contrast, compared with untrained men, distance runners exhibited a significantly greater slope (1.42 ± 0.11 mg cm(-2)/min/°C, P sprinters and untrained men, whereas distance runners showed a significantly higher induced SR compared with untrained men. The sweating function was not improved in sprinters who have trained 2-3 h/day, 5 days/week, for at least 3 years compared with untrained men, although the VO2 max was markedly greater in sprinters. Thus, there is a case that daily training was not sufficient to improve sweating function in sprinters relative to those in distance runners.

  1. Chloride and potassium conductances of cultured human sweat ducts

    DEFF Research Database (Denmark)

    Novak, I; Pedersen, P S; Larsen, Erik Hviid

    1992-01-01

    The purpose of this study was to characterize the ion conductances, in particular those for Cl- and K+, of human sweat duct cells grown in primary culture. Sweat duct cells from healthy individuals were grown to confluence on a dialysis membrane, which was then mounted in a mini-Ussing chamber...

  2. Sweat chloride concentrations in children with Idiopathic Nephrotic Syndrome.

    Science.gov (United States)

    Guglani, Lokesh; Moir, Devin; Jain, Amrish

    2016-01-01

    Idiopathic Nephrotic Syndrome (INS) has been believed to cause a false positive elevation of sweat chloride concentrations, as measured by the sweat test. Sweat tests were done for 11 children with acute onset INS at admission and again while they were in remission, with results being compared to normal historical controls. The initial sweat chloride concentration for 10 patients was normal (mean16.7 ± 11.02 mmol/L) and 1 patient had inadequate collection. This latter patient and two others were excluded during follow-up because of diagnoses other than INS. Sweat test results for the eight INS patients during follow up remained unchanged when they were in remission (16.94 ± 7.88 mmol/L; P = 0.98; Wilcoxon Matched-Pairs Signed Rank Test). In comparing sweat chloride concentrations from INS patients to those from 20 historical control subjects, we found no significant differences (Mann-Whitney Test; initial vs. control P = 0.643; follow up vs. control P = 0.806). INS does not cause a false positive sweat test. Further studies should be done to objectively assess the conditions that have been reported to affect sweat chloride concentrations. © 2015 Wiley Periodicals, Inc.

  3. Sweat rate and fluid intake in young elite basketball players on the FIBA Europe U20 Championship

    Directory of Open Access Journals (Sweden)

    Vukašinović-Vesić Milica

    2015-01-01

    Full Text Available Background/Aim. Previous investigations in many sports indicated that continued exercise, especially in hot environments, can cause high sweat rate and huge water and electrolyte losses, thus impairing the performance of athletes. Most these studies were conducted during training sessions, but rarely during an official competition. Therefore, the aim of our study was to determine pre- and post-competition hydration, fluid intake and sweat loss of young elite basketball players during the FIBA Europe U20 Championship. Methods. The study included 96 basketball male players, (19 ± 0.79 years of eight national teams. Ambient temperature was 30 ± 2ºC, humidity 55 ± 4% and the mean playing time in game 18.8 ± 10.5 min. The following parameters related to hydration status were measured: fluid intake, urine output, sweat rate, percent of dehydration, urine parameters (specific gravity, color and osmolarity, body mass and body surface area. Results. We found that the mean fluid intake was 1.79 ± 0.8 L/h, sweat rate 2.7 ± 0.9 L/h, urine output 55 ± 61 mL and the percentage of dehydration 0.99 ± 0.7%. According to urine osmolarity more than 75% of players were dehydrated before the game and the process continued during the game. The difference in body mass (0.9 ± 0.7 kg before and after the game was statistically significant. There were statistically significant correlations between the sweat rate and fluid intake, urine osmolarity, body mass loss, body surface area and percentage of dehydration. Fluid intake correlated with the percentage of dehydration, body mass loss, urine specific gravity and urine color. The sweat rate, which varied between the teams, was the highest for centers when this parameter was calculated on the effective time in game. Conclusion. Most of the athletes start competition dehydrated, fail to compensate sweat loss during the game and continue to be dehydrated, regardless what kind of drink was used. These results

  4. Textile Functionalization and Its Effects on the Release of Silver Nanoparticles into Artificial Sweat.

    Science.gov (United States)

    Wagener, Sandra; Dommershausen, Nils; Jungnickel, Harald; Laux, Peter; Mitrano, Denise; Nowack, Bernd; Schneider, Gregor; Luch, Andreas

    2016-06-07

    This study addresses the release of total silver (Ag) and silver nanoparticles (Ag-NPs) from textiles into artificial sweat, particularly considering the functionalization technology used in textile finishing. Migration experiments were conducted for four commercially available textiles and for six laboratory-prepared textiles. Two among these lab-prepared textiles represent materials in which Ag-NPs were embedded within the textile fibers (composites), whereas the other lab-prepared textiles contain Ag particles on the respective fiber surfaces (coatings). The results indicate a smaller release of total Ag from composites in comparison to surface-coated textiles. The particulate fraction determined within the artificial sweat was negligible for most textiles, meaning that the majority of the released Ag is present as dissolved Ag. It is also relevant to note that nanotextiles do not release more particulate Ag than conventional Ag textiles. The results rather indicate that the functionalization type is the most important parameter affecting the migration. Furthermore, after measuring different Ag-NP types in their pristine form with inductively coupled plasma mass spectrometry in the single particle mode, there is evidence that particle modifications, like surface coating, may also influence the dissolution behavior of the Ag-NPs in the sweat solutions. These factors are important when discussing the likelihood of consumer exposure.

  5. A comparison of fingerprint sweat corrosion of different alloys of brass.

    Science.gov (United States)

    Sykes, Stephanie; Bond, John W

    2013-01-01

    Fingerprint sweat from 40 donors was deposited onto samples of five α and α + β phase brasses, comprising five alloys with different copper and zinc concentrations, two of which also had the addition of small concentrations of lead. Visual grading of the visibility of the corrosion revealed that brasses with the least amount of zinc produced the most visible and fully formed fingerprints from the most donors. Consideration of previously reported mechanisms for the corrosion of brass suggests red copper (I) oxide as a likely corrosion product for low zinc brasses, and a consideration of the color, composition, and solubility of fingerprint sweat corrosion products suggests that copper (I) oxide produces good contrast and visibility with the brass substrate. Scanning electron microscope images of the corrosion of all five alloys confirmed the enhanced contrast between corroded and uncorroded areas for low zinc alloys. © 2012 American Academy of Forensic Sciences.

  6. Glass Frit Dissolution Influenced by Material Composition and the Water Content in Iodide/Triiodide Electrolyte of Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Katrine Flarup Jensen

    2013-01-01

    Full Text Available To ensure long-term stable dye-sensitized solar cells (DSCs and modules, a hermetic sealing is required. This research investigates the chemical stability of I-/I3- redox electrolyte and four different glass frits (GFs. Sintered GF layers were openly exposed to nonaqueous redox electrolyte and redox electrolyte with 1, 5, and 10 wt% H2O in thin, encapsulated cells. The change in I3− absorbance was assigned to a reaction between the GF and I-/I3- electrolyte and was used to evaluate the chemical stability of the different GFs. The I3− absorbance change was monitored over 100 days. Two out of the four GFs were unstable when H2O was added to the redox electrolyte. The H2O caused metal ion leaching which was determined from EDX analysis of the inorganic remains of electrolyte samples. A GF based on Bi2O3–SiO2–B2O3 with low bond strength leached bismuth into electrolyte and formed the BiI3- complex. A ZnO–SiO2–Al2O3-based GF also became unstable when H2O was added to the redox electrolyte. Leaching of zinc ions due to exchange with H+ resulted in the formation of a zinc-iodine compound which caused I3− depletion. By applying the test design to different types of GFs, the material suitability in the DSC working environment was investigated.

  7. Effects of Solvent Composition on Liquid Range, Glass Transition, and Conductivity of Electrolytes of a (Li, Cs)PF6 Salt in EC-PC-EMC Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Michael S.; Li, Qiuyan; Li, Xing; Xu, Wu; Xu, Kang

    2017-05-10

    Electrolytes of 1 M LiPF6 (lithium hexafluorophosphate) and 0.05 M CsPF6 (cesium hexafluorophosphate) in EC-PC-EMC (ethylene carbonate-propylene carbonate-ethyl methyl carbonate) solvents of varying solvent compositions were studied for the effects of solvent composition on the lower limit of liquid range, viscosity (as reflected by the glass transition temperature), and electrolytic conductivity. In addition, a ternary phase diagram of EC-PC-EMC was constructed and crystallization temperatures of EC and EMC were calculated to assist the interpretation and understanding of the change of liquid range with solvent composition. A function based on Vogel-Fulcher-Tammann equation was fitted to the conductivity data in their entirety and plotted as conductivity surfaces in solvent composition space for more direct and clear comparisons and discussions. Changes of viscosity and dielectric constant of the solvents with their composition, in relation to those of the solvent components, were found to be underlying many of the processes studied.

  8. Improved Devices for Collecting Sweat for Chemical Analysis

    Science.gov (United States)

    Feeback, Daniel L.; Clarke, Mark S. F.

    2011-01-01

    Improved devices have been proposed for collecting sweat for biochemical analysis especially for determination of the concentration of Ca2+ ions in sweat as a measure of loss of Ca from bones. Unlike commercially available sweat-collection patches used previously in monitoring osteoporosis and in qualitative screening for some drugs, the proposed devices would not allow evaporation of the volatile chemical components (mostly water) of sweat. Moreover, the proposed devices would be designed to enable determination of the volumes of collected sweat. From these volumes and the quantities of Ca2+ and/or other analytes as determined by other means summarized below, one could determine the concentrations of the analytes in sweat. A device according to the proposal would be flexible and would be worn like a commercial sweat-collection patch. It would be made of molded polydimethylsiloxane (silicone rubber) or other suitable material having properties that, for the purpose of analyzing sweat, are similar to those of glass. The die for molding the silicone rubber would be fabricated by a combination of lithography and electroplating. The die would reproducibly form, in the silicone rubber, a precisely defined number of capillary channels per unit area, each channel having a precisely defined volume. Optionally, electrodes for measuring the Ca2+ content of the sweat could be incorporated into the device. The volume of sweat collected in the capillary channels of the device would be determined from (1) the amount of light or radio waves of a given wavelength absorbed by the device and (2) the known geometry of the array of capillary channels. Then, in one of two options, centrifugation would be performed to move the sweat from the capillary tubes to the region containing the electrodes, which would be used to measure the Ca2+ content by a standard technique. In the other option, centrifugation would be performed to remove the sweat from the device to make the sweat available

  9. Effect of salt supplementation on the rate of inadequate sweat collection for infants less than 3 months of age referred for the sweat test.

    Science.gov (United States)

    Guglani, Lokesh; Abdulhamid, Ibrahim

    2015-01-01

    Sweat testing in young infants (≤ 3 months) with a positive newborn screen for Cystic Fibrosis (CF) can yield higher rates of inadequate sweat collection. The role of salt supplements in improving sweat collection has not been studied before. All young infants referred to our CF center for sweat testing were randomized to either receive salt supplements {1/8th teaspoon salt (750 mg)} mixed in formula feeds 1 day prior to sweat testing (study group) or no salt supplement (controls). Of the 151 young infants that underwent sweat testing over 18 months, 75 received salt supplements, while 76 did not. A total of 9 (11.8%) infants in the salt supplement group had inadequate sweat collection, as compared to 4 (5.2%) infants in the control group (p = 0.16, Fisher's Exact Test). Oral salt supplementation for young infants prior to sweat testing does not help to reduce the rates of inadequate sweat collection.

  10. Flexible nanoporous tunable electrical double layer biosensors for sweat diagnostics

    Science.gov (United States)

    Munje, Rujuta D.; Muthukumar, Sriram; Panneer Selvam, Anjan; Prasad, Shalini

    2015-09-01

    An ultra-sensitive and highly specific electrical double layer (EDL) modulated biosensor, using nanoporous flexible substrates for wearable diagnostics is demonstrated with the detection of the stress biomarker cortisol in synthetic and human sweat. Zinc oxide thin film was used as active region in contact with the liquid i.e. synthetic and human sweat containing the biomolecules. Cortisol detection in sweat was accomplished by measuring and quantifying impedance changes due to modulation of the double layer capacitance within the electrical double layer through the application of a low orthogonally directed alternating current (AC) electric field. The EDL formed at the liquid-semiconductor interface was amplified in the presence of the nanoporous flexible substrate allowing for measuring the changes in the alternating current impedance signal due to the antibody-hormone interactions at diagnostically relevant concentrations. High sensitivity of detection of 1 pg/mL or 2.75 pmol cortisol in synthetic sweat and 1 ng/mL in human sweat is demonstrated with these novel biosensors. Specificity in synthetic sweat was demonstrated using a cytokine IL-1β. Cortisol detection in human sweat was demonstrated over a concentration range from 10-200 ng/mL.

  11. Solid state electrolyte systems

    Energy Technology Data Exchange (ETDEWEB)

    Pederson, L.R.; Armstrong, B.L.; Armstrong, T.R. [Pacific Northwest Lab., Richland, WA (United States)] [and others

    1997-12-01

    Lanthanum gallates are a new family of solid electrolytes that exhibit high ionic conductivity and are stable to high temperatures. Compositions have been developed that are as much as a factor of two more conductive than yttria-stabilized zirconia at a given temperature, through partial replacement of lanthanum by calcium, strontium, and/or barium and through partial replacement of gallium by magnesium. Oxide powders were prepared using combustion synthesis techniques developed in this laboratory; these were sintered to >95% of theoretical density and consisted of a single crystalline phase. Electrical conductivities, electron and ion transference numbers, thermal expansion, and phase behavior were evaluated as a function of temperature and oxygen partial pressure. A key advantage of the use of lanthanum gallate electrolytes in solid oxide fuel cells is that the temperature of operation may be lowered to perhaps 800 C, yet provide approximately the same power density as zirconia-based cells operating at 1000 C. Ceramic electrolytes that conduct both oxygen ions and electrons are potentially useful to passively separate pure oxygen from an air source at low cost. In such materials, an oxygen ion flux in one direction is charge-compensated by an opposing electron flux. The authors have examined a wide range of mixed ion and electron conducting perovskite ceramics in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, where M = Sr, Ca, and Ba, and N = Pr, Mn, Ni, Cu, Ti, and Al, as well as mixed conducting brownmillerite ceramics, and have characterized oxygen permeation behavior, defect chemistry, structural and phase stability, and performance as cathodes.

  12. The effect of heat acclimation on sweat microminerals: Artifact of surface contamination

    Science.gov (United States)

    Heat acclimation (HA) reportedly conveys conservation in sweat micromineral concentrations when sampled from arm sweat, but time course is unknown. The observation that comprehensive cleaning of the skin surface negates sweat micromineral reductions during prolonged sweating raises the question of w...

  13. Dissolution of cemented carbide powders in artificial sweat: implications for cobalt sensitization and contact dermatitis.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Harvey, Christopher J; Virji, M Abbas; Day, Gregory A

    2010-10-06

    Skin exposure to cobalt-containing materials can cause systemic immune sensitization and upon repeat contact, elicitation of allergic contact dermatitis (ACD). Data on cobalt dissolution rates are needed to calculate uptake through skin and for development of models to understand risk of sensitization or dermatitis. The purpose of this research was to measure the dissolution kinetics of feedstock and process-sampled powders encountered in the production of hard metal alloys using artificial sweat. The physicochemical properties of each material were characterized prior to evaluation of dissolution behavior. Variations in artificial sweat solvent pH and chemistry were used to understand critical factors in dissolution. Dissolution of cobalt, tungsten, and tungsten carbide was often biphasic with the initial rapid phase being up to three orders of magnitude faster than the latter long-term phase. Artificial sweat pH did not influence dissolution of cobalt or tungsten carbide. Solvent composition had little influence on observed dissolution rates; however, vitamin E suppressed the dissolution of cobalt and tungsten carbide from sintered particles obtained from a chamfer grinder. There was no effect of particle size on dissolution of feedstock cobalt, tungsten, tungsten carbide, and admixture powders. Particle physicochemical properties influenced observed dissolution rates with more cobalt and tungsten carbide dissolving from chamfer grinder particles compared to the feedstock powders or admixture powder. Calculations using the observed dissolution rates revealed that skin exposure concentrations were similar to concentrations known to induce cobalt sensitization and elicit ACD. Observed dissolution rates for cobalt in artificial sweat indicate that dermal uptake may be sufficient to induce cobalt sensitization and allergic dermatitis.

  14. Corrosion Performance of Cu-Based Coins in Artificial Sweat

    Directory of Open Access Journals (Sweden)

    J. Porcayo-Calderon

    2016-01-01

    Full Text Available The performance of different Cu-based coins in artificial sweat was evaluated. The electrochemical behavior of the coins was determined by potentiodynamic polarization curves, linear polarization resistance, and electrochemical impedance spectroscopy. Regardless of the chemical composition of the Cu-based coins, they showed similar polarization curves; particularly, the observed similarity in the anodic zone suggests that the corrosion mechanism is the same in all cases. The presence of Ni and Zn does not appreciably affect the corrosion resistance of Cu. However, the presence of both elements affects the corrosion resistance of Cu. Electrochemical impedance spectroscopy measurements showed the presence of three time constants with very similar characteristics, again indicating that the main corrosion mechanism is the same in all cases. Equivalent circuits confirmed that the corrosion performance of the Ni-Zn-Cu coins depends on the Zn/Ni ratio, such that decreasing this value decreases the corrosion resistance of the alloy. In general, nickel has a detrimental effect due to the formation of highly soluble Ni-based corrosion products.

  15. Studies on the effect of acid treated TiO2 on the electrical and tensile properties of hexanoyl chitosan-polystyrene-LiCF3SO3 composite polymer electrolytes

    Science.gov (United States)

    Hanif, Nur Shazlinda Muhammad; Shahril, Nur Syuhada Mohd; Azmar, Amisha; Winie, Tan

    2015-08-01

    Composite polymer electrolytes (CPEs) comprised of hexanoyl chitosan:polystyrene (90:10) blend, lithium triflouromethanesulfonate (LiCF3SO3) salt and titanium oxide (TiO2) filler were prepared by solution casting technique. The TiO2 fillers were treated with 2% sulphuric acid (H2SO4) aqueous solution. The effect of acid treated TiO2 on the electrical and tensile properties of the electrolytes were investigated. Acid treated TiO2 decreased the electrolyte conductivity. Both the dielectric constant and dielectric loss decrease with increasing frequency and increases with increasing temperature. Relaxation times for ionic carriers were extracted from the loss tangent maximum peak at various temperatures. A distribution of relaxation time implied the non-Debye response. At all frequencies, ac conductivity increases with increasing temperature. An enhancement in the Young's modulus was observed with the addition of TiO2. The Young's modulus increases with increasing TiO2 content. This is discussed using the percolation concept.

  16. Studies on the effect of acid treated TiO{sub 2} on the electrical and tensile properties of hexanoyl chitosan-polystyrene-LiCF{sub 3}SO{sub 3} composite polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Hanif, Nur Shazlinda Muhammad; Shahril, Nur Syuhada Mohd; Azmar, Amisha; Winie, Tan [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia)

    2015-08-28

    Composite polymer electrolytes (CPEs) comprised of hexanoyl chitosan:polystyrene (90:10) blend, lithium triflouromethanesulfonate (LiCF{sub 3}SO{sub 3}) salt and titanium oxide (TiO{sub 2}) filler were prepared by solution casting technique. The TiO{sub 2} fillers were treated with 2% sulphuric acid (H{sub 2}SO{sub 4}) aqueous solution. The effect of acid treated TiO{sub 2} on the electrical and tensile properties of the electrolytes were investigated. Acid treated TiO{sub 2} decreased the electrolyte conductivity. Both the dielectric constant and dielectric loss decrease with increasing frequency and increases with increasing temperature. Relaxation times for ionic carriers were extracted from the loss tangent maximum peak at various temperatures. A distribution of relaxation time implied the non-Debye response. At all frequencies, ac conductivity increases with increasing temperature. An enhancement in the Young’s modulus was observed with the addition of TiO{sub 2}. The Young’s modulus increases with increasing TiO{sub 2} content. This is discussed using the percolation concept.

  17. Composite Gel Polymer Electrolyte Based on Poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) with Modified Aluminum-Doped Lithium Lanthanum Titanate (A-LLTO) for High-Performance Lithium Rechargeable Batteries.

    Science.gov (United States)

    Le, Hang T T; Ngo, Duc Tung; Kalubarme, Ramchandra S; Cao, Guozhong; Park, Choong-Nyeon; Park, Chan-Jin

    2016-08-17

    A composite gel polymer electrolyte (CGPE) based on poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) polymer that includes Al-doped Li0.33La0.56TiO3 (A-LLTO) particles covered with a modified SiO2 (m-SiO2) layer was fabricated through a simple solution-casting method followed by activation in a liquid electrolyte. The obtained CGPE possessed high ionic conductivity, a large electrochemical stability window, and interfacial stability-all superior to that of the pure gel polymer electrolyte (GPE). In addition, under a highly polarized condition, the CGPE effectively suppressed the growth of Li dendrites due to the improved hardness of the GPE by the addition of inorganic A-LLTO/m-SiO2 particles. Accordingly, the Li-ion polymer and Li-O2 cells employing the CGPE exhibited remarkably improved cyclability compared to cells without CGPE. In particular, the CGPE as a protection layer for the Li metal electrode in a Li-O2 cell was effective in blocking the contamination of the Li electrode by oxygen gas or impurities diffused from the cathode side while suppressing the Li dendrites.

  18. Genetics Home Reference: cold-induced sweating syndrome

    Science.gov (United States)

    ... my area? Other Names for This Condition CISS CNTF receptor-related disorders Crisponi syndrome Sohar-Crisponi syndrome ... of cardiotrophin-like cytokine, a second ligand for ciliary neurotrophic factor receptor, leads to cold-induced sweating syndrome in ...

  19. Cystic fibrosis with normal sweat chloride concentration: case report

    Directory of Open Access Journals (Sweden)

    Silva Filho Luiz Vicente Ferreira da

    2003-01-01

    Full Text Available Cystic fibrosis is a genetic disease usually diagnosed by abnormal sweat testing. We report a case of an 18-year-old female with bronchiectasis, chronic P. aeruginosa infection, and normal sweat chloride concentrations who experienced rapid decrease of lung function and clinical deterioration despite treatment. Given the high suspicion ofcystic fibrosis, broad genotyping testing was performed, showing a compound heterozygous with deltaF508 and 3849+10kb C->T mutations, therefore confirming cystic fibrosis diagnosis. Although the sweat chloride test remains the gold standard for the diagnosis of cystic fibrosis, alternative diagnostic tests such as genotyping and electrophysiologic measurements must be performed if there is suspicion of cystic fibrosis, despite normal or borderline sweat chloride levels.

  20. Sweat Gland Progenitors in Development, Homeostasis, and Wound Repair

    Science.gov (United States)

    Lu, Catherine; Fuchs, Elaine

    2014-01-01

    The human body is covered with several million sweat glands. These tiny coiled tubular skin appendages produce the sweat that is our primary source of cooling and hydration of the skin. Numerous studies have been published on their morphology and physiology. Until recently, however, little was known about how glandular skin maintains homeostasis and repairs itself after tissue injury. Here, we provide a brief overview of sweat gland biology, including newly identified reservoirs of stem cells in glandular skin and their activation in response to different types of injuries. Finally, we discuss how the genetics and biology of glandular skin has advanced our knowledge of human disorders associated with altered sweat gland activity. PMID:24492848

  1. \\'Sweat Equity\\': Women\\'s Participation in Subsidised Housing in ...

    African Journals Online (AJOL)

    Abstract. The notion of \\"sweat equity\\" has been promoted as an integral part of subsidised housing in South African Housing policy. It\\'s tougher for females, though. Africa Insight Vol.34(2/3) 2004: 58-64 ...

  2. Influence of sex and growth hormone deficiency on sweating

    DEFF Research Database (Denmark)

    Main, K; Nilsson, K O; Skakkebaek, N E

    1991-01-01

    Sweat secretion rate (SSR) was measured by the pilocarpine iontophoresis test in (a) 254 healthy children and adolescents (aged 6.0 to 19.2 years, mean age 11.2 years); in (b) 58 healthy adults (aged 20.4 to 75.2 years, mean age 37.6 years); and in (c) eight prepubertal patients with growth hormone...... in sweat excretion rate from childhood to adulthood showed a difference between the sexes. Both pre-pubertal and pubertal boys had a lower secretion value than adult men (p less than 0.001 and 0.01, respectively), whereas girls showed higher secretion values than adult women (p less than 0.01 and p less...... min-1). We conclude that (a) sweat secretion pattern in children shows a significant sex difference and (b) sweating in children is dependent on growth hormone....

  3. Cancer treatment: dealing with hot flashes and night sweats

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000826.htm Cancer treatment: dealing with hot flashes and night sweats To use ... stress reduction. Learning how to decrease stress and anxiety may help relieve hot flashes in some people. ...

  4. Lack of harmonization in sweat testing for cystic fibrosis

    DEFF Research Database (Denmark)

    Lindegaard Christiansen, Anne; Nybo, Mads

    2014-01-01

    Abstract Introduction. Sweat testing is used in the diagnosis of cystic fibrosis. Interpretation of the sweat test depends, however, on the method performed since conductivity, osmolality and chloride concentration all can be measured as part of a sweat test. The aim of this study...... fibrosis. Because diagnosing cystic fibrosis is a combined effort between local pediatric departments, biochemical and genetic departments and cystic fibrosis centers, a national harmonization is necessary to assure correct clinical use....... a normal and grey zone or a pathological value. Cut-off values for normal, grey and pathological areas were like the reference intervals inconsistent. Conclusion. There is inconsistent use of NPU codes, reference intervals and interpretation of sweat conductivity used in the process of diagnosing cystic...

  5. Observation of the sweating in lipstick by scanning electron microscopy.

    Science.gov (United States)

    Seo, S Y; Lee, I S; Shin, H Y; Choi, K Y; Kang, S H; Ahn, H J

    1999-06-01

    The relationship between the wax matrix in lipstick and sweating has been investigated by observing the change of size and shape of the wax matrix due to sweating by Scanning Electron Microscopy (SEM). For observation by SEM, a lipstick sample was frozen in liquid nitrogen. The oil in the lipstick was then extracted in cold isopropanol (-70 degrees C) for 1-3 days. After the isopropanol was evaporated, the sample was sputtered with gold and examined by SEM. The change of wax matrix underneath the surface from fine, uniform structure to coarse, nonuniform structure resulted from the caking of surrounding wax matrix. The oil underneath the surface migrated to the surface of lipstick with sweating; consequently the wax matrix in that region was rearranged into the coarse matrix. In case of flamed lipstick, sweating was delayed and the wax matrix was much coarser than that of the unflamed one. The larger wax matrix at the surface region was good for including oil. The effect of molding temperature on sweating was also studied. As the molding temperature rose, sweating was greatly reduced and the size of the wax matrix increased. It was found that sweating was influenced by the compatibility of wax and oil. A formula consisting of wax and oil that have good compatibility has a tendency to reduce sweating and increase the size of the wax matrix. When pigments were added to wax and oil, the size of the wax matrix was changed, but in all cases sweating was increased due to the weakening of the binding force between wax and oil. On observing the thick membrane of wax at the surface of lipstick a month after molding it was also found that sweating was influenced by ageing. In conclusion, the structure of the wax matrix at the surface region of lipstick was changed with the process of flaming, molding temperature, compatibility of wax and oil, addition of pigment, and ageing. In most cases, as the size of the wax matrix was increased, sweating was reduced and delayed.

  6. Sweat lipid mediator profiling: a noninvasive approach for cutaneous research.

    Science.gov (United States)

    Agrawal, Karan; Hassoun, Lauren A; Foolad, Negar; Pedersen, Theresa L; Sivamani, Raja K; Newman, John W

    2017-01-01

    Recent advances in analytical and sweat collection techniques provide new opportunities to identify noninvasive biomarkers for the study of skin inflammation and repair. This study aims to characterize the lipid mediator profile including oxygenated lipids, endocannabinoids, and ceramides/sphingoid bases in sweat and identify differences in these profiles between sweat collected from nonlesional sites on the unflared volar forearm of subjects with and without atopic dermatitis (AD). Adapting routine procedures developed for plasma analysis, over 100 lipid mediators were profiled using LC-MS/MS and 58 lipid mediators were detected in sweat. Lipid mediator concentrations were not affected by sampling or storage conditions. Increases in concentrations of C30-C40 [NS] and [NdS] ceramides, and C18:1 sphingosine, were observed in the sweat of study participants with AD despite no differences being observed in transepidermal water loss between study groups, and this effect was strongest in men (P Sweat mediator profiling may therefore provide a noninvasive diagnostic for AD prior to the presentation of clinical signs.

  7. Wearable Sweat Rate Sensors for Human Thermal Comfort Monitoring.

    Science.gov (United States)

    Sim, Jai Kyoung; Yoon, Sunghyun; Cho, Young-Ho

    2018-01-19

    We propose watch-type sweat rate sensors capable of automatic natural ventilation by integrating miniaturized thermo-pneumatic actuators, and experimentally verify their performances and applicability. Previous sensors using natural ventilation require manual ventilation process or high-power bulky thermo-pneumatic actuators to lift sweat rate detection chambers above skin for continuous measurement. The proposed watch-type sweat rate sensors reduce operation power by minimizing expansion fluid volume to 0.4 ml through heat circuit modeling. The proposed sensors reduce operation power to 12.8% and weight to 47.6% compared to previous portable sensors, operating for 4 hours at 6 V batteries. Human experiment for thermal comfort monitoring is performed by using the proposed sensors having sensitivity of 0.039 (pF/s)/(g/m 2 h) and linearity of 97.9% in human sweat rate range. Average sweat rate difference for each thermal status measured in three subjects shows (32.06 ± 27.19) g/m 2 h in thermal statuses including 'comfortable', 'slightly warm', 'warm', and 'hot'. The proposed sensors thereby can discriminate and compare four stages of thermal status. Sweat rate measurement error of the proposed sensors is less than 10% under air velocity of 1.5 m/s corresponding to human walking speed. The proposed sensors are applicable for wearable and portable use, having potentials for daily thermal comfort monitoring applications.

  8. Trapped sweat in basketball uniforms and the effect on sweat loss estimates.

    Science.gov (United States)

    Baker, Lindsay B; Reimel, Adam J; Sopeña, Bridget C; Barnes, Kelly A; Nuccio, Ryan P; De Chavez, Peter John D; Stofan, John R; Carter, James M

    2017-09-01

    The aims of this study were to determine: (1) trapped sweat (TS) in basketball uniforms and the effect on sweat loss (SL) estimates during a laboratory-based basketball simulation protocol; (2) the impact of exercise intensity, body mass, age, and SL on TS; and (3) TS during on-court training to assess the ecological validity of the laboratory-based results. Twenty-four recreational/competitive male basketball players (23 ± 10 years, 77.0 ± 16.7 kg) completed three randomized laboratory-based trials (Low, Moderate, and High intensity) consisting of 150-min intermittent exercise. Eighteen elite male players (23 ± 4 years, 92.0 ± 20.6 kg) were observed during coach-led, on-court training. Nude and clothed body mass were measured pre and postexercise to determine TS. Data are mean ± SD. There was a significant effect of intensity on SL and TS ( P  < 0.001, Lowsweat and TS was 0.11 ± 0.15 kg (8.0 ± 5.1% SL). During Moderate, subjects lost 1.60 ± 0.56 kg sweat and TS was 0.21 ± 0.21 kg (11.6 ± 6.3% SL). During High, subjects lost 2.12 ± 0.66 kg sweat and TS was 0.38 ± 0.28 kg (16.0 ± 7.4% SL). Multiple regression and partial correlation analysis suggested TS was significantly related to SL ( P  < 0.0001; partial r  = 0.81-0.89), whereas the contributions of body mass ( P  = 0.22-0.92) and age ( P  = 0.29-0.44) were not significant. TS during on-court training was 0.35 ± 0.36 kg, which was associated with a 14.1 ± 11.5% underestimation in SL, and was not statistically different than laboratory-based results ( P  = 0.59). Clothed body mass measurements should be used with caution, as TS is highly variable and can cause a significant underestimation in SL in athletes with high sweating rates. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological

  9. Lithium ion conducting electrolytes

    Science.gov (United States)

    Angell, Charles Austen; Liu, Changle; Xu, Kang; Skotheim, Terje A.

    1999-01-01

    The present invention relates generally to highly conductive alkali-metal ion non-crystalline electrolyte systems, and more particularly to novel and unique molten (liquid), rubbery, and solid electrolyte systems which are especially well suited for use with high current density electrolytic cells such as primary and secondary batteries.

  10. Lithium ion conducting electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Angell, C.A.; Liu, C.; Xu, K.; Skotheim, T.A.

    1999-10-05

    The present invention relates generally to highly conductive alkali-metal ion non-crystalline electrolyte systems, and more particularly to novel and unique molten (liquid), rubbery, and solid electrolyte systems which are especially well suited for use with high current density electrolytic cells such as primary and secondary batteries.

  11. Matrigel basement membrane matrix induces eccrine sweat gland cells to reconstitute sweat gland-like structures in nude mice.

    Science.gov (United States)

    Li, Haihong; Chen, Lu; Zeng, Shaopeng; Li, Xuexue; Zhang, Xiang; Lin, Changmin; Zhang, Mingjun; Xie, Sitian; He, Yunpu; Shu, Shenyou; Yang, Lvjun; Tang, Shijie; Fu, Xiaobing

    2015-03-01

    Severe burn results in irreversible damage to eccrine sweat glands, for which no effective treatment is available. Interaction between the extracellular matrix and epithelial cells is critical for proper three-dimensional organization and function of the epithelium. Matrigel-embedded eccrine sweat gland cells were subcutaneously implanted into the inguinal regions of nude mice. Two weeks later, the Matrigel plugs were removed and evaluated for series of detection items. Sweat gland cells developed into sweat gland-like structures in the Matrigel plugs based on: (1) de novo formation of tubular-like structures with one or more hollow lumens, (2) expression of epithelial and sweat gland markers (pancytokeratin, CK5/7/14/19, α-SMA and CEA), (3) basement membrane formation, (4) myoepithelial cells presenting in and encompassing the tubular-like structures, (5) cellular polarization, evident by the expression of tight junction proteins (claudin-1 and ZO-2), anchoring junctions (desmoglein-1 and -2 and E-cadherin) and CEA in the luminal membrane, (6) expression of proteins related to sweat secretion and absorption (Na(+)-K(+)-ATPase α/β, Na(+)-K(+)-2Cl-cotranspoter 1, Na(+)/H(+) exchanger 1, aquaporin-5, epithelial sodium channel, cystic fibrosis transmembrane conductance regulator, potassium channel and vacuolar-type H+-ATPase), and (7) about 20% of the tubular-like structures are de novo coils and 80% are de novo ducts. This study provides not only an excellent model to study eccrine sweat gland development, cytodifferentiation and reconstitution, but also an in vivo model for regeneration of eccrine sweat glands. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Sweat Farm Road Fire in Georgia

    Science.gov (United States)

    2007-01-01

    Dense plumes of blue-white smoke billowed from the Sweat Farm Road Fire in southern Georgia on April 19, 2007, when the Landsat 5 satellite captured this detailed image. The fire started on April 16, when a tree fell on a power line and, fanned by strong winds, quickly exploded into a major fire. By April 19, the fire had forced officials to close several roads, including U.S. Highway 1, and to evacuate hundreds of people from the perimeter of the city of Waycross, the silver cluster along the top edge of the image. The nearness of the fire is evident in the dark brown, charred land just south of the city. The active fire front is along the south edge of the burned area, where the flames are eating into the dark green hardwood forests, pine plantations, and shrubs in Okefenokee Swamp. Because of the difficult terrain, the fire and the adjoining Big Turnaround Complex fire are expected to burn until significant rain falls, said the morning report issued by the Southern Area Coordination Center on May 4. 'In the long term, the burning of the swamp will ultimately benefit the swamp wilderness habitat, which is a fire-dependent ecosystem,' said a press release issued from the Okefenokee National Wildlife Refuge on May 4. Such ecosystems require fire to remain healthy. In the case of southern pine forests, many pine species need fire to remove litter from the ground and release soil nutrients so that new seedlings can grow.

  13. Nanoporous polymer electrolyte

    Science.gov (United States)

    Elliott, Brian [Wheat Ridge, CO; Nguyen, Vinh [Wheat Ridge, CO

    2012-04-24

    A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at 25.degree. C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

  14. Solid polymer electrolyte from phosphorylated chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Fauzi, Iqbal, E-mail: arcana@chem.itb.ac.id; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Groups, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24

    Recently, the need of secondary battery application continues to increase. The secondary battery which using a liquid electrolyte was indicated had some weakness. A solid polymer electrolyte is an alternative electrolytes membrane which developed in order to replace the liquid electrolyte type. In the present study, the effect of phosphorylation on to polymer electrolyte membrane which synthesized from chitosan and lithium perchlorate salts was investigated. The effect of the component’s composition respectively on the properties of polymer electrolyte, was carried out by analyzed of it’s characterization such as functional groups, ion conductivity, and thermal properties. The mechanical properties i.e tensile resistance and the morphology structure of membrane surface were determined. The phosphorylation processing of polymer electrolyte membrane of chitosan and lithium perchlorate was conducted by immersing with phosphoric acid for 2 hours, and then irradiated on a microwave for 60 seconds. The degree of deacetylation of chitosan derived from shrimp shells was obtained around 75.4%. Relative molecular mass of chitosan was obtained by viscometry method is 796,792 g/mol. The ionic conductivity of chitosan membrane was increase from 6.33 × 10{sup −6} S/cm up to 6.01 × 10{sup −4} S/cm after adding by 15 % solution of lithium perchlorate. After phosphorylation, the ionic conductivity of phosphorylated lithium chitosan membrane was observed 1.37 × 10{sup −3} S/cm, while the tensile resistance of 40.2 MPa with a better thermal resistance. On the strength of electrolyte membrane properties, this polymer electrolyte membrane was suggested had one potential used for polymer electrolyte in field of lithium battery applications.

  15. Solid polymer electrolyte from phosphorylated chitosan

    Science.gov (United States)

    Fauzi, Iqbal; Arcana, I. Made

    2014-03-01

    Recently, the need of secondary battery application continues to increase. The secondary battery which using a liquid electrolyte was indicated had some weakness. A solid polymer electrolyte is an alternative electrolytes membrane which developed in order to replace the liquid electrolyte type. In the present study, the effect of phosphorylation on to polymer electrolyte membrane which synthesized from chitosan and lithium perchlorate salts was investigated. The effect of the component's composition respectively on the properties of polymer electrolyte, was carried out by analyzed of it's characterization such as functional groups, ion conductivity, and thermal properties. The mechanical properties i.e tensile resistance and the morphology structure of membrane surface were determined. The phosphorylation processing of polymer electrolyte membrane of chitosan and lithium perchlorate was conducted by immersing with phosphoric acid for 2 hours, and then irradiated on a microwave for 60 seconds. The degree of deacetylation of chitosan derived from shrimp shells was obtained around 75.4%. Relative molecular mass of chitosan was obtained by viscometry method is 796,792 g/mol. The ionic conductivity of chitosan membrane was increase from 6.33 × 10-6 S/cm up to 6.01 × 10-4 S/cm after adding by 15 % solution of lithium perchlorate. After phosphorylation, the ionic conductivity of phosphorylated lithium chitosan membrane was observed 1.37 × 10-3 S/cm, while the tensile resistance of 40.2 MPa with a better thermal resistance. On the strength of electrolyte membrane properties, this polymer electrolyte membrane was suggested had one potential used for polymer electrolyte in field of lithium battery applications.

  16. Preparation and characterization of Nafion - TiO{sub 2} composite electrolytes for application in proton exchange membrane fuel cells; Preparacao e caracterizacao de eletrolitos compositos Nafion - TiO{sub 2} para aplicacao em celulas a combustivel de membrana de troca protonica

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Bruno Ribeiro de

    2008-11-06

    The fabrication and characterization of Nafion - TiO{sub 2} composites, and the use of such electrolytes in PEM (Proton Exchange Membrane) fuel cell operating at high temperature (130 deg C) were studied. The operation of a PEM fuel cell at such high temperature is considered as an effective way to promote fast electrode reaction kinetics, high diffusional transport, and high tolerance to the carbon monoxide fuel contaminant. The polymer Nafion{sup R} is the most used electrolyte in PEM fuel cells due to its high proton conductivity. However, the proton transport in Nafion is dependent on the water content in the polymeric membrane. The need of absorbed water in the polymer structure limits the operation of the fuel cell to temperatures close to 100 deg C, above which Nafion exhibits a fast decrease of the ionic conductivity. In order to increase the performance of the electrolyte operating at high temperatures, Nafion-TiO{sub 2} composites have been prepared by casting. The addition of titania hygroscopic particles to the polymeric matrix aims at the enhancement of the humidification of the electrolyte at temperatures above 100 deg C. Three types of titania particles with different specific surface area and morphology have been investigated. Nafion-based composites with the addition of titania nanoparticles, in the 2.5-15 wt.% range, with nearly spherical shape and specific surface area up to approx. 115 m{sup 2}g{sup -1} were found to have higher glass transition temperature than the polymer. Such an increase improves the stability of the electrolyte during the fuel cell operation at high temperatures. The addition of titania-derived nanotubes results in a pronounced increase of the performance of PEM fuel cell operating at 130 deg C. In this composite, the high specific surface area and the tubular shape of the inorganic phase are responsible for the measured increase of both the absorption and retention of water of the composite electrolyte. Nonetheless, the

  17. A Real-Time Wireless Sweat Rate Measurement System for Physical Activity Monitoring.

    Science.gov (United States)

    Brueck, Andrew; Iftekhar, Tashfin; Stannard, Alicja B; Yelamarthi, Kumar; Kaya, Tolga

    2018-02-10

    There has been significant research on the physiology of sweat in the past decade, with one of the main interests being the development of a real-time hydration monitor that utilizes sweat. The contents of sweat have been known for decades; sweat provides significant information on the physiological condition of the human body. However, it is important to know the sweat rate as well, as sweat rate alters the concentration of the sweat constituents, and ultimately affects the accuracy of hydration detection. Towards this goal, a calorimetric based flow-rate detection system was built and tested to determine sweat rate in real time. The proposed sweat rate monitoring system has been validated through both controlled lab experiments (syringe pump) and human trials. An Internet of Things (IoT) platform was embedded, with the sensor using a Simblee board and Raspberry Pi. The overall prototype is capable of sending sweat rate information in real time to either a smartphone or directly to the cloud. Based on a proven theoretical concept, our overall system implementation features a pioneer device that can truly measure the rate of sweat in real time, which was tested and validated on human subjects. Our realization of the real-time sweat rate watch is capable of detecting sweat rates as low as 0.15 µL/min/cm², with an average error in accuracy of 18% compared to manual sweat rate readings.

  18. Systematic review focusing on the excretion and protection roles of sweat in the skin.

    Science.gov (United States)

    Peng, Yan; Cui, Xiao; Liu, Yanhua; Li, Yaoyin; Liu, Jian; Cheng, Biao

    2014-01-01

    The skin excretes substances primarily through sweat glands. Several conditions have been demonstrated to be associated with diminished sweating. However, few studies have concentrated on the metabolism and excretion of sweat. This review focuses on the relationship between temperature and the thermoregulatory efficacy of sweat, and then discusses the excretion of sweat, which includes the metabolism of water, minerals, proteins, vitamins as well as toxic substances. The potential role of sweat secretion in hormone homeostasis and the effects on the defense system of the skin are also clarified. © 2014 S. Karger AG, Basel.

  19. Lithium carbon batteries with solid polymer electrolyte; Accumulateur lithium carbone a electrolyte solide polymere

    Energy Technology Data Exchange (ETDEWEB)

    Andrieu, X.; Boudin, F. [Alcatel Alsthom Recherche, 91 - Marcoussis (France)

    1996-12-31

    The lithium carbon batteries studied in this paper use plasticized polymer electrolytes made with passive polymer matrix swollen by a liquid electrolyte with a high ionic conductivity (> 10{sup -3} S/cm at 25 deg. C). The polymers used to prepare the gels are polyacrylonitrile (PAN) and vinylidene poly-fluoride (PVdF). The electrochemical and physical properties of these materials are analyzed according to their composition. The behaviour of solid electrolytes with different materials of lithium ion insertion (graphite and LiNiO{sub 2}) are studied and compared to liquid electrolytes. The parameters taken into account are the reversible and irreversible capacities, the cycling performance and the admissible current densities. Finally, complete lithium ion batteries with gelled electrolytes were manufactured and tested. (J.S.) 2 refs.

  20. Study of sample preparation for quantitative analysis of amino acids in human sweat by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Delgado-Povedano, M M; Calderón-Santiago, M; Priego-Capote, F; Luque de Castro, M D

    2016-01-01

    The determination of physiological levels of amino acids is important to aid in the diagnosis and treatment of several diseases and nutritional status of individuals. Amino acids are frequently determined in biofluids such as blood (serum or plasma) and urine; however, there are less common biofluids with different concentration profiles of amino acids that could be of interest. One of these biofluids is sweat that can be obtained in a non-invasive manner and is characterized by low complex composition. The analysis of amino acids in human sweat requires the development of sample preparation strategies according to the sample matrix and small collected volume. The influence of sample preparation on the quantitative analysis of amino acids in sweat by LC-MS/MS has been assessed through a comparison between two strategies: dilution of sweat and centrifugal microsolid-phase extraction (c-μSPE). In both cases, several dilution factors were assayed for in-depth knowledge of the matrix effects, and the use of c-μSPE provided the best results in terms of accuracy. The behavior of the target analytes was a function of the dilution factor, thus providing a pattern for sample preparation that depended on the amino acid to be determined. The concentration of amino acids in sweat ranges between 6.20 ng mL(-1) (for homocysteine) and 259.77 µg mL(-1) (for serine) with precision, expressed as relative standard deviation, within 1.1-21.4%. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Human Elimination of Organochlorine Pesticides: Blood, Urine, and Sweat Study.

    Science.gov (United States)

    Genuis, Stephen J; Lane, Kevin; Birkholz, Detlef

    2016-01-01

    Background . Many individuals have been exposed to organochlorinated pesticides (OCPs) through food, water, air, dermal exposure, and/or vertical transmission. Due to enterohepatic reabsorption and affinity to adipose tissue, OCPs are not efficiently eliminated from the human body and may accrue in tissues. Many epidemiological studies demonstrate significant exposure-disease relationships suggesting OCPs can alter metabolic function and potentially lead to illness. There is limited study of interventions to facilitate OCP elimination from the human body. This study explored the efficacy of induced perspiration as a means to eliminate OCPs. Methods . Blood, urine, and sweat (BUS) were collected from 20 individuals. Analysis of 23 OCPs was performed using dual-column gas chromatography with electron-capture detectors. Results . Various OCPs and metabolites, including DDT, DDE, methoxychlor, endrin, and endosulfan sulfate, were excreted into perspiration. Generally, sweat samples showed more frequent OCP detection than serum or urine analysis. Many OCPs were not readily detected in blood testing while still being excreted and identified in sweat. No direct correlation was found among OCP concentrations in the blood, urine, or sweat compartments. Conclusions . Sweat analysis may be useful in detecting some accrued OCPs not found in regular serum testing. Induced perspiration may be a viable clinical tool for eliminating some OCPs.

  2. Early-stage mucinous sweat gland adenocarcinoma of eyelid

    Directory of Open Access Journals (Sweden)

    Nizawa T

    2011-05-01

    Full Text Available Tomohiro Nizawa1, Toshiyuki Oshitari1, Ryuta Kimoto1, Fusae Kajita1, Jiro Yotsukura1, Kaoru Asanagi1, Takayuki Baba1, Yoko Takahashi2, Takashi Oide2, Takako Kiyokawa2, Takashi Kishimoto2, Shuichi Yamamoto11Department of Ophthalmology and Visual Science, 2Department of Molecular Pathology, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, JapanAbstract: We present the findings of an early-stage primary mucinous sweat gland adenocarcinoma in the lower eyelid of a Japanese patient. The patient was a 73-year-old man who had had a nodule on the left lower eyelid for two years. He was referred to our hospital with a diagnosis of a swollen chalazion. The clinical and histopathological records were reviewed and the mass was excised. Histopathological examination revealed a mucinous sweat gland adenocarcinoma. Postoperative magnetic resonance imaging and positron emission tomography excluded systemic metastases. After the histopathological findings, a complete surgical excision of the margins of the adenocarcinoma was performed, with histopathological confirmation of negative margins. After the final histopathological examination, the patient was diagnosed with a primary mucinous sweat gland adenocarcinoma of the left eyelid. Six months after the surgery, no recurrence has been observed. Because the appearance of mucinous sweat gland adenocarcinoma of the eyelid is quite variable, the final diagnosis can only be made by histopathological examination. A complete surgical excision is recommended.Keywords: complete surgical excision, eyelid, initial stage, mucinous sweat gland adenocarcinoma

  3. Sweat, the driving force behind normal skin: an emerging perspective on functional biology and regulatory mechanisms.

    Science.gov (United States)

    Murota, Hiroyuki; Matsui, Saki; Ono, Emi; Kijima, Akiko; Kikuta, Junichi; Ishii, Masaru; Katayama, Ichiro

    2015-01-01

    The various symptoms associated with excessive or insufficient perspiration can significantly reduce a patient's quality of life. If a versatile and minimally invasive method could be established for returning sweat activity to normalcy, there is no question that it could be used in the treatment of many diseases that are believed to involve perspiration. For this reason, based on an understanding of the sweat-gland control function and sweat activity, it was necessary to conduct a comprehensive search for the factors that control sweating, such as the central and peripheral nerves that control sweat-gland function, the microenvironment surrounding the sweat glands, and lifestyle. We focused on the mechanism by which atopic dermatitis leads to hypohidrosis and confirmed that histamine inhibits acetylcholinergic sweating. Acetylcholine promotes the phosphorylation of glycogen synthesis kinase 3β (GSK3β) in the sweat-gland secretory cells and leads to sensible perspiration. By suppressing the phosphorylation of GSK3β, histamine inhibits the movement of sweat from the sweat-gland secretory cells through the sweat ducts, which could presumably be demonstrated by dynamic observations of the sweat glands using two-photon microscopy. It is expected that the discovery of new factors that control sweat-gland function can contribute to the treatment of diseases associated with dyshidrosis. Copyright © 2014 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Acquired defects in CFTR-dependent β-adrenergic sweat secretion in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Courville, Clifford A; Tidwell, Sherry; Liu, Bo; Accurso, Frank J; Dransfield, Mark T; Rowe, Steven M

    2014-02-25

    Smoking-induced chronic obstructive pulmonary disease (COPD) is associated with acquired systemic cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction. Recently, sweat evaporimetry has been shown to efficiently measure β-adrenergic sweat rate and specifically quantify CFTR function in the secretory coil of the sweat gland. To evaluate the presence and severity of systemic CFTR dysfunction in smoking-related lung disease using sweat evaporimetry to determine CFTR-dependent sweat rate. We recruited a cohort of patients consisting of healthy never smokers (N = 18), healthy smokers (12), COPD smokers (25), and COPD former smokers (12) and measured β-adrenergic sweat secretion rate with evaporative water loss, sweat chloride, and clinical data (spirometry and symptom questionnaires). β-adrenergic sweat rate was reduced in COPD smokers (41.9 ± 3.4, P sweat chloride was significantly greater in COPD smokers (32.8 ± 3.3, P sweat rate and female gender (β = 0.26), age (-0.28), FEV1% (0.35), dyspnea (-0.3), and history of smoking (-0.27; each P sweat rate was significantly reduced in COPD patients, regardless of smoking status, reflecting acquired CFTR dysfunction and abnormal gland secretion in the skin that can persist despite smoking cessation. β-adrenergic sweat rate and sweat chloride are associated with COPD severity and clinical symptoms, supporting the hypothesis that CFTR decrements have a causative role in COPD pathogenesis.

  5. Excretion of ciprofloxacin in sweat and multiresistant Staphylococcus epidermidis

    DEFF Research Database (Denmark)

    Høiby, N; Jarløv, J O; Kemp, M

    1997-01-01

    BACKGROUND: Staphylococcus epidermidis develops resistance to ciprofloxacin rapidly. That this antibiotic is excreted in apocrine and eccrine sweat of healthy individuals might be the reason for the development of such resistance. We assessed whether S epidermidis isolated from the axilla and nasal...... flora of healthy people could develop resistance to ciprofloxacin after a 1-week course of this antibiotic. METHODS: The concentration of ciprofloxacin in sweat was measured in seven volunteers after oral administration of 750 mg ciprofloxacin twice daily for 7 days, and the development of resistance...... in S epidermidis from axilla and nostrils was monitored during and 2 months after the treatment. Genotyping of S epidermidis was done by restriction fragment length polymorphism. FINDINGS: The mean concentration of ciprofloxacin in sweat increased during the 7 days of treatment-from 2.2 micrograms/mL 2...

  6. Normal sweat chloride test does not rule out cystic fibrosis.

    Science.gov (United States)

    Başaran, Abdurrahman Erdem; Karataş-Torun, Nimet; Maslak, İbrahim Cemal; Bingöl, Ayşen; Alper, Özgül M

    2017-01-01

    Başaran AE, Karataş-Torun N, Maslak İC, Bingöl A, Alper ÖM. Normal sweat chloride test does not rule out cystic fibrosis. Turk J Pediatr 2017; 59: 68-70. A 5-month-old patient presented with complaints of fever and cough. He was hospitalized with the diagnosis of bronchopneumonia and pseudo-Bartter's syndrome. Patient was further investigated for diagnosis of cystic fibrosis. The chloride (Cl) level in sweat was determined within the normal range (25.1 mmol/L, 20.3 mmol/L). CFTR (Cystic Fibrosis Transmembrane Regulator gene; NM_000492.2) genotyping results were positive for p.E92K; p.F1052V mutations. The patient was diagnosed with cystic fibrosis. In our patient, with features of CF and normal sweat test, mutation analysis was helpful for the diagnosis of cystic fibrosis.

  7. Impact of blanching, sweating and drying operations on pungency, aroma and color of Piper borbonense.

    Science.gov (United States)

    Weil, M; Shum Cheong Sing, A; Méot, J M; Boulanger, R; Bohuon, P

    2017-03-15

    Low pungency, high aromatic potential and red color, give to Piper borbonense its originality when compared to Piper nigrum. Effects of blanching, sweating and drying on these characteristics were assessed. The three operations had no impact on the concentration of piperine and essential oil but affected the composition of essential oil slightly and considerably affected the color of the pepper. The "wet process", including blanching, sweating and drying, had the largest impact on the composition of aroma, increasing para-cymene content by 89% and reducing safrole content by 33% in dried pepper compared to fresh. Blanching increased the drying rate thus reducing drying time. Drying had a major impact on color, which changed from red to brown. The biggest differences observed led to reductions of 2.2, 7.9 and 8.4units in L∗, a∗ and b∗ values, when chromatic values measured in fresh pepper were compared to those of dried pepper. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Sweat chloride as a biomarker of CFTR activity: proof of concept and ivacaftor clinical trial data.

    Science.gov (United States)

    Accurso, Frank J; Van Goor, Fredrick; Zha, Jiuhong; Stone, Anne J; Dong, Qunming; Ordonez, Claudia L; Rowe, Steven M; Clancy, John Paul; Konstan, Michael W; Hoch, Heather E; Heltshe, Sonya L; Ramsey, Bonnie W; Campbell, Preston W; Ashlock, Melissa A

    2014-03-01

    We examined data from a Phase 2 trial {NCT00457821} of ivacaftor, a CFTR potentiator, in cystic fibrosis (CF) patients with aG551D mutation to evaluate standardized approaches to sweat chloride measurement and to explore the use of sweat chloride and nasal potential difference (NPD) to estimate CFTR activity. Sweat chloride and NPD were secondary endpoints in this placebo-controlled, multicenter trial. Standardization of sweat collection, processing,and analysis was employed for the first time. Sweat chloride and chloride ion transport (NPD) were integrated into a model of CFTR activity. Within-patient sweat chloride determinations showed sufficient precision to detect differences between dose-groups and assess ivacaftor treatment effects. Analysis of changes in sweat chloride and NPD demonstrated that patients treated with ivacaftor achieved CFTR activity equivalent to approximately 35%–40% of normal. Sweat chloride is useful in multicenter trials as a biomarker of CFTR activity and to test the effect of CFTR potentiators.

  9. Study on new BaCe{sub 0.7}In{sub 0.3}O{sub 3−δ}–Gd{sub 0.1}Ce{sub 0.9}O{sub 2−δ} composite electrolytes for intermediate-temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fengguang; Dang, Junjie; Hou, Jie; Qian, Jing; Zhu, Zhiwen; Wang, Zhongtao [CAS Key Laboratory of Materials for Energy Conversion, Department of Material Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Liu, Wei, E-mail: wliu@ustc.edu.cn [CAS Key Laboratory of Materials for Energy Conversion, Department of Material Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-08-05

    Highlights: • New BCI–GDC composite electrolytes were synthesized using a one-step method for SOFCs. • The sintering temperature decreases as the BCI content increases. • The conductivity and OCV values enhanced as the GDC content increases. • The possible interface effects between BCI and GDC were analyzed. - Abstract: New mixed ionic conductors, BaCe{sub 0.7}In{sub 0.3}O{sub 3−δ}–Gd{sub 0.1}Ce{sub 0.9}O{sub 2−δ} (BCI–GDC, weight ratio, 3:7, 5:5 and 7:3), were synthesized via a one-step citric acid–nitrate gel combustion method as electrolyte materials for solid oxide fuel cells (SOFCs). X-ray diffraction patterns of BCI–GDC indicated that there was no impurity phase formed after sintering at high temperature up to 1400 °C. Scanning electron microscopic study of BCI–GDC depicted dense grain morphology. Single fuel cells were prepared and the corresponding electrochemical performances were tested. The sintering temperature of the dense composite electrolyte membranes decrease as the BCI content increases because of the sintering aids of In element. All samples with the composite electrolyte showed higher open circuit voltage (OCV) values than the single phase GDC. In addition, Electrical conductivity of the composite electrolyte under different atmospheres at different temperatures confirmed that the BCI–GDC exhibited high mixed oxygen ionic and protonic conduction. The test results indicated that the conductivity and OCV values of the composite electrolyte enhanced as the GDC content increases, and the optimum performance was found to be BCI3–GDC7 compared with the pure BCI and GDC electrolyte. The possible interface effects were suggested to explain this phenomenon. Our results not only provide one new promising composite electrolyte material for intermediate-temperature SOFCs but the composition dependence can actually provide a guide for the material design, optimization.

  10. Bullous lesions, sweat gland necrosis and rhabdomyolysis in alcoholic coma

    Directory of Open Access Journals (Sweden)

    Neelakandhan Asokan

    2014-01-01

    Full Text Available A 42-year-old male developed hemorrhagic bullae and erosions while in alcohol induced coma. The lesions were limited to areas of the body in prolonged contact with the ground in the comatose state. He developed rhabdomyolysis, progressing to acute renal failure (ARF. Histopathological examination of the skin showed spongiosis, intraepidermal vesicles, and necrosis of eccrine sweat glands with denudation of secretory epithelial lining cells. With supportive treatment and hemodialysis, the patient recovered in 3 weeks time. This is the first reported case of bullous lesions and sweat gland necrosis occurring in alcohol-induced coma complicated by rhabdomyolysis and ARF.

  11. Sources of Variation in Sweat Chloride Measurements in Cystic Fibrosis

    Science.gov (United States)

    Blackman, Scott M.; Raraigh, Karen S.; Corvol, Harriet; Rommens, Johanna M.; Pace, Rhonda G.; Boelle, Pierre-Yves; McGready, John; Sosnay, Patrick R.; Strug, Lisa J.; Knowles, Michael R.; Cutting, Garry R.

    2016-01-01

    Rationale: Expanding the use of cystic fibrosis transmembrane conductance regulator (CFTR) potentiators and correctors for the treatment of cystic fibrosis (CF) requires precise and accurate biomarkers. Sweat chloride concentration provides an in vivo assessment of CFTR function, but it is unknown the degree to which CFTR mutations account for sweat chloride variation. Objectives: To estimate potential sources of variation for sweat chloride measurements, including demographic factors, testing variability, recording biases, and CFTR genotype itself. Methods: A total of 2,639 sweat chloride measurements were obtained in 1,761 twins/siblings from the CF Twin-Sibling Study, French CF Modifier Gene Study, and Canadian Consortium for Genetic Studies. Variance component estimation was performed by nested mixed modeling. Measurements and Main Results: Across the tested CF population as a whole, CFTR gene mutations were found to be the primary determinant of sweat chloride variability (56.1% of variation) with contributions from variation over time (e.g., factors related to testing on different days; 13.8%), environmental factors (e.g., climate, family diet; 13.5%), other residual factors (e.g., test variability; 9.9%), and unique individual factors (e.g., modifier genes, unique exposures; 6.8%) (likelihood ratio test, P < 0.001). Twin analysis suggested that modifier genes did not play a significant role because the heritability estimate was negligible (H2 = 0; 95% confidence interval, 0.0–0.35). For an individual with CF, variation in sweat chloride was primarily caused by variation over time (58.1%) with the remainder attributable to residual/random factors (41.9%). Conclusions: Variation in the CFTR gene is the predominant cause of sweat chloride variation; most of the non-CFTR variation is caused by testing variability and unique environmental factors. If test precision and accuracy can be improved, sweat chloride measurement could be a valuable biomarker

  12. Wearable technologies for sweat rate and conductivity sensors

    CERN Document Server

    Salvo, Pietro

    2012-01-01

    Hauptbeschreibung Wearable sensors present a new frontier in the development of monitoring techniques. They are of great importance in sectors such as sports and healthcare, as they permit the continuous monitoring of physiological and biological elements, such as ECG and human sweat. Until recently, this could only be carried out in specialized laboratories in the presence of cumbersome, and usually, expensive devices. Sweat monitoring sensors integrated onto textile substrates are not only part of a new field of work but, they also represent the first attempt to implement such an

  13. Immediate Wheal Reactivity to Autologous Sweat in Atopic Dermatitis Is Associated with Clinical Severity, Serum Total and Specific IgE and Sweat Tryptase Activity.

    Science.gov (United States)

    Ilves, Tiina; Virolainen, Anu; Harvima, Ilkka Tapani

    2016-01-01

    Sweating can worsen atopic dermatitis (AD). The purpose of this work was to study the associations between reactivity to autologous sweat and the clinical severity of AD as well as investigate the possible wheal-inducing factors of sweat. Intracutaneous skin tests with autologous sweat were performed on 50 AD patients and 24 control subjects. In skin biopsies, tryptase and PAR-2 were enzyme and immunohistochemically stained. The associations between skin test reactivity and sweat histamine concentration, tryptase or chymase activity levels, tryptase or PAR-2 expression and AD clinical severity or IgE levels were investigated. The wheal reactions in the intracutaneous tests with autologous sweat were positive, weakly positive and negative in 38, 34 and 28% of the AD patients, respectively, and in 4, 46 and 50% of the healthy controls, respectively (p = 0.008). In AD, the wheal reaction was associated significantly with clinical severity, serum total and specific IgE levels and sweat tryptase activity, but not with sweat histamine and chymase. In nonlesional AD skin, the percentage of PAR-2+ mast cells (MCs) or the number of tryptase+ MCs did not differ significantly between the intracutaneous test reactivity groups. Reactivity to autologous sweat correlates with the clinical severity of AD, and tryptase may be one of the factors involved in the sweat-induced wheal. © 2016 S. Karger AG, Basel.

  14. Transient elevation of sweat chloride concentration in a malnourished girl with the Mauriac syndrome.

    Science.gov (United States)

    Polack, F P; Transue, D J; Belknap, W M; Freij, B J; Aughton, D J

    1995-02-01

    Elevated sweat chloride concentration in a patient with Mauriac syndrome has been reported only once. The authors of that report regarded their patient's underlying malnutrition, and not Mauriac syndrome per se, as the cause of the elevated sweat chloride concentration. We describe a second example of transient elevation of sweat chloride concentration, which confirms that the malnutrition intrinsic to Mauriac syndrome, rather than the syndrome itself, was the probable cause of elevated sweat chloride values.

  15. PEO nanocomposite polymer electrolyte for solid state symmetric ...

    Indian Academy of Sciences (India)

    Physical and electrochemical properties of polyethylene oxide (PEO)-based nanocomposite solid polymer electrolytes (NPEs) were investigated for symmetric capacitor applications. Nanosize fillers, i.e., Al2O3 and SiO2 incorporated polymer electrolyte exhibited higher ionic conductivity than those with filler-free composites ...

  16. Improved protocols for the study of urinary electrolyte excretion and blood pressure in rodents: use of gel food and stepwise changes in diet composition.

    Science.gov (United States)

    Nizar, Jonathan M; Bouby, Nadine; Bankir, Lise; Bhalla, Vivek

    2018-01-10

    Many experimental protocols in rodents require the comparison of groups that are fed different diets. Changes in dietary electrolyte and/or fat content can influence food intake, which can potentially introduce bias or confound the results. Unpalatable diets slow growth or cause weight loss, which is exacerbated by housing the animals in individual metabolic cages or by surgery. For balance studies in mice, small body weight and food intake, and low urinary flow can amplify these challenges. Powder food can be administered as a gel with the addition of a desired amount of water, electrolytes, drugs (if any), and a small amount of agar. We describe here how the use of gel food, to vary water, Na, K, and fat content can reduce weight loss and improve reproducibility of intake, urinary excretion, and blood pressure in rodents. In addition, mild food restriction reduces the inter-individual variability and inter-group differences in food intake and associated variables, thus, improving the statistical power of the experiment. Finally, we also demonstrate the advantages of using gel food for weight-based drug dosing. These protocols can improve the accuracy and reproducibility of experimental data where dietary manipulations are needed, and are especially advisable in rodent studies related to water balance, obesity and blood pressure.

  17. A new method of artificial latent fingerprint creation using artificial sweat and inkjet printer.

    Science.gov (United States)

    Hong, Sungwook; Hong, Ingi; Han, Aleum; Seo, Jin Yi; Namgung, Juyoung

    2015-12-01

    In order to study fingerprinting in the field of forensic science, it is very important to have two or more latent fingerprints with identical chemical composition and intensity. However, it is impossible to obtain identical fingerprints, in reality, because fingerprinting comes out slightly differently every time. A previous research study had proposed an artificial fingerprint creation method in which inkjet ink was replaced with amino acids and sodium chloride solution: the components of human sweat. But, this method had some drawbacks: divalent cations were not added while formulating the artificial sweat solution, and diluted solutions were used for creating weakly deposited latent fingerprint. In this study, a method was developed for overcoming the drawbacks of the methods used in the previous study. Several divalent cations were added in this study because the amino acid-ninhydrin (or some of its analogues) complex is known to react with divalent cations to produce a photoluminescent product; and, similarly, the amino acid-1,2-indanedione complex is known to be catalyzed by a small amount of zinc ions to produce a highly photoluminescent product. Also, in this study, a new technique was developed which enables to adjust the intensity when printing the latent fingerprint patterns. In this method, image processing software is used to control the intensity of the master fingerprint patterns, which adjusts the printing intensity of the latent fingerprints. This new method opened the way to produce a more realistic artificial fingerprint in various strengths with one artificial sweat working solution. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Sweat lipid mediator profiling: a non-invasive approach for cutaneous research

    Science.gov (United States)

    Sweat is a complex biological fluid with potential diagnostic value for the investigation of skin disorders. Previous efforts in sweat testing focused on analysis of small molecules and ions for forensic and diagnostic testing, but with advances in analytical and sweat collection techniques, there h...

  19. Sweat it Out : Johannes de Gorter and Sudorifics in the Dutch Republic

    NARCIS (Netherlands)

    Verwaal, Ruben

    2017-01-01

    Today, many go for a run, cover themselves under blankets, or sit in the sauna believing that they can ‘sweat out’ the common cold. Whereas modern medicine has falsified the efficacy of sweating as treatment, this paper considers the development of medical research about sweating in the early modern

  20. Crying for a Vision: The Native American Sweat Lodge Ceremony as Therapeutic Intervention

    Science.gov (United States)

    Garrett, Michael Tlanusta; Torres-Rivera, Edil; Brubaker, Michael; Portman, Tarrell Awe Agahe; Brotherton, Dale; West-Olatunji, Cirecie; Conwill, William; Grayshield, Lisa

    2011-01-01

    The Native American sweat lodge ceremony or sweat therapy is being used increasingly in various medical, mental health, correctional, and substance abuse treatment centers serving both Native and non-Native clients. This article explores the sweat lodge ceremony's background, elements of Native American spirituality, origin story, cultural…

  1. Pituitary adenylate cyclase-activating polypeptide promotes eccrine gland sweat secretion

    DEFF Research Database (Denmark)

    Sasaki, S; Watanabe, J; Ohtaki, H

    2017-01-01

    BACKGROUND: Sweat secretion is the major function of eccrine sweat glands; when this process is disturbed (paridrosis), serious skin problems can arise. To elucidate the causes of paridrosis, an improved understanding of the regulation, mechanisms and factors underlying sweat production is requir...

  2. Novel Nonflammable Electrolytes for Secondary Magnesium Batteries and High Voltage Electrolytes for Electrochemcial Supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Brian

    2008-12-30

    Magnesium has been used successfully in primary batteries, but its use in rechargeable cells has been stymied by the lack of suitable non-aqueous electrolyte that can conduct Mg+2 species, combined with poor stripping and plating properties. The development of a suitable cathode material for rechargeable magnesium batteries has also been a roadblock, but a nonflammable electrolyte is key. Likewise, the development of safe high voltage electrochemical supercapaitors has been stymied by the use of flammable solvents in the liquid electrolyte; to wit, acetonitrile. The purpose of the research conducted in this effort was to identify useful compositions of magnesium salts and polyphosphate solvents that would enable magnesium ions to be cycled within a secondary battery design. The polyphosphate solvents would provide the solvent for the magnesium salts while preventing the electrolyte from being flammable. This would enable these novel electrolytes to be considered as an alternative to THF-based electrolytes. In addition, we explored several of these solvents together with lithium slats for use as high voltage electrolytes for carbon-based electrochemical supercapacitors. The research was successful in that: 1) Magnesium imide dissolved in a phosphate ester solvent that contains a halogented phosphate ester appears to be the preferred electrolyte for a rechargeable Mg cell. 2) A combination of B-doped CNTs and vanadium phosphate appear to be the cathode of choice for a rechargeable Mg cell by virtue of higher voltage and better reversibility. 3) Magnesium alloys appear to perform better than pure magnesium when used in combination with the novel polyphosphate electrolytes. Also, this effort has established that Phoenix Innovation's family of phosphonate/phosphate electrolytes together with specific lithium slats can be used in supercapacitor systems at voltages of greater than 10V.

  3. based gel polymer electrolytes

    Indian Academy of Sciences (India)

    vity at ambient temperature (Wright 1975; Martuscelli et al 1984). Generally solid polymer electrolytes have many advantages, viz. high ionic conductivity, high specific energy, wide electrochemical stability windows, light and easy processibility. Apart from this, polymer electrolyte studies have been carried out in poly(vinyl ...

  4. Towards Prognostics of Electrolytic Capacitors

    Data.gov (United States)

    National Aeronautics and Space Administration — A remaining useful life prediction algorithm and degradation model for electrolytic capacitors is presented. Electrolytic capacitors are used in several applications...

  5. Synthesis and ceramic processing of zirconia alumina composites for application as solid oxide fuel cell electrolytes; Sintese e processamento de compositos de zirconia-alumina para aplicacao como eletrolito em celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Rafael Henrique Lazzari

    2007-07-01

    The global warmness and the necessity to obtain clean energy from alternative methods than petroleum raises the importance of developing cleaner and more efficient systems of energy generation, among then, the solid oxide fuel cell (SOFC). Cubic stabilized zirconia (CSZ) has been the most studied material as electrolyte in SOFC, due to its ionic conductivity and great stability at operation conditions. However, its low fracture toughness difficulties its application as a thin layer, what could lead to an improvement of cell efficiency. In this sense, the alumina addition in CSZ forms a composite, which can shift its mechanical properties, without compromising its electrical properties. In this work, coprecipitation synthesis route and ceramic processing of zirconia-alumina composites were studied, in order to establish optimum conditions to attain high density, homogeneous microstructure, and better mechanical properties than CSZ, without compromising ionic conductivity. For this purpose, composites containing up to 40 wt % of alumina, in a 9 mol % yttria-stabilized zirconia (9Y-CSZ) matrix were evaluated. In order to optimize the synthesis of the composites, a preliminary study of powder obtaining and processing were carried out, at compositions containing 20 wt % of alumina, in 9Y-CSZ. The ceramic powders were characterized by helium picnometry, X-ray diffraction, scanning electronic microscopy, transmission electronic microscopy, thermogravimetry, differential scanning calorimetry, granulometry by laser diffraction and gas adsorption (BET). The characterization of sinterized compacts were performed by X-ray diffraction, scanning electron microscopy, optical microscopy, density measurements, Vickers indentation and impedance spectroscopy. The obtained results show that the alumina addition, in the 9Y-CSZ matrix powders, raises the specific surface area, promotes deagglomeration of powders and elevates the oxides crystallization temperature, requiring higher

  6. Plasma electrolytic oxidation of tantalum

    Directory of Open Access Journals (Sweden)

    Petković Marija

    2012-01-01

    Full Text Available This paper is a review of our research on the plasma electrolytic oxidation (PEO process of tantalum in 12-tungstosilicic acid. For the characterization of microdischarges during PEO, real-time imaging and optical emission spectroscopy (OES were used. The surface morphology, chemical and phase composition of oxide coatings were investigated by AFM, SEM-EDS and XRD. Oxide coating morphology is strongly dependent on PEO time. The elemental components of PEO coatings are Ta, O, Si and W. The oxide coatings are partly crystallized and mainly composed of WO3, Ta2O5 and SiO2.

  7. The Sweat Lodge Ceremony in Challenge/Adventure Programming.

    Science.gov (United States)

    Quinn, William J.; Smith, Thomas E.

    This paper advocates the potentials of "sweat lodge" rituals for adventure education programs. Historically, rituals and ceremonies have been instrumental in passing major philosophical and sociological paradigms from one generation to the next. However, there is little theory and research about how ritual and ceremony results in the…

  8. Do elephants need to sweat? | Wright | African Zoology

    African Journals Online (AJOL)

    An adequate rate of evaporative water loss is considered essential for the maintenance of thermal balance in the elephant in warm climatic conditions. Histological studies have failed to reveal the existence of sweat glands in elephant skin. Transepidermal water-loss rate has been measured and shown to be sufficiently ...

  9. the comfort, measured by means of a sweating manikin (waltertm)

    African Journals Online (AJOL)

    user

    Anton F Botha*, Marguerite E Stoffberg & Lawrance Hunter. ABSTRACT. With the growing importance of clothing comfort in South African and overseas markets for locally produced clothing, the Council for. Scientific Industrial Research (CSIR) acquired an advanced sweating fabric manikin for measuring clothing comfort.

  10. Pituitary adenylate cyclase-activating polypeptide promotes eccrine gland sweat secretion.

    Science.gov (United States)

    Sasaki, S; Watanabe, J; Ohtaki, H; Matsumoto, M; Murai, N; Nakamachi, T; Hannibal, J; Fahrenkrug, J; Hashimoto, H; Watanabe, H; Sueki, H; Honda, K; Miyazaki, A; Shioda, S

    2017-02-01

    Sweat secretion is the major function of eccrine sweat glands; when this process is disturbed (paridrosis), serious skin problems can arise. To elucidate the causes of paridrosis, an improved understanding of the regulation, mechanisms and factors underlying sweat production is required. Pituitary adenylate cyclase-activating polypeptide (PACAP) exhibits pleiotropic functions that are mediated via its receptors [PACAP-specific receptor (PAC1R), vasoactive intestinal peptide (VIP) receptor type 1 (VPAC1R) and VPAC2R]. Although some studies have suggested a role for PACAP in the skin and several exocrine glands, the effects of PACAP on the process of eccrine sweat secretion have not been examined. To investigate the effect of PACAP on eccrine sweat secretion. Reverse transcriptase-polymerase chain reaction and immunostaining were used to determine the expression and localization of PACAP and its receptors in mouse and human eccrine sweat glands. We injected PACAP subcutaneously into the footpads of mice and used the starch-iodine test to visualize sweat-secreting glands. Immunostaining showed PACAP and PAC1R expression by secretory cells from mouse and human sweat glands. PACAP immunoreactivity was also localized in nerve fibres around eccrine sweat glands. PACAP significantly promoted sweat secretion at the injection site, and this could be blocked by the PAC1R-antagonist PACAP6-38. VIP, an agonist of VPAC1R and VPAC2R, failed to induce sweat secretion. This is the first report demonstrating that PACAP may play a crucial role in sweat secretion via its action on PAC1R located in eccrine sweat glands. The mechanisms underlying the role of PACAP in sweat secretion may provide new therapeutic options to combat sweating disorders. © 2016 British Association of Dermatologists.

  11. Development and demonstration of process and components for the control of aluminum-air-battery electrolyte composition through the precipitation of aluminum trihydroxide. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Swansiger, T. G.; Misra, C.

    1982-05-11

    Physical property data on density, viscosity, and electrical conductivity were developed and reduced to correlation form for synthetic electrolytes containing nominally 7 g/L Sn and 0.20 g/L Ga in 3,4,5,6 M NaOH. Concentrations of Al(OH)/sub 4/ were selected at six levels for each NaOH concentration and ranged from 0 to as high as 4 M Al(OH)/sub 4/ at 6 M NaOH. Measurements of each property were made at 25, 40, 60, and 80 C. The effect of the Sn and Ga impurities was to increase density by a relatively small percentage, increase viscosity by a significant percentage, and decrease electrical conductance by a significant percentage. Isothermal, batch precipitation experiments at 40, 60, and 80 C were utilized to develop data from which kinetic and solubility correlations were derived as functions of electrolyte and system parameters. Precipitation rate was negatively affected by tin in solution, with a 40% reduction in the rate constant being attributed to 0.06 M Sn. Both Sn and Ga co-precipitated with the Al(OH)/sub 3/ to an extent strongly dependent on temperature. Very high precipitation rates resulted in Na levels in product exceeding the target level of 0.24% Na on the hydrate basis. The incorporation of Na in product was also a strong function of temperature. A total of 108 computer simulations were performed and documented to delineate the region of feasible operation with respect to meeting the aluminate production specification. A full-scale precipitator was operated in a continuous mode to assess production rate, population changes with time, and hardware aspects. A digester was used to perform the function of an Al-Air battery, that is to drive Al(OH)/sub 4//sup -/ into solution. Results are presented in detail. (WHK)

  12. Interrelationships among Grain Size, Surface Composition, Air Stability, and Interfacial Resistance of Al-Substituted Li7La3Zr2O12 Solid Electrolytes.

    Science.gov (United States)

    Cheng, Lei; Wu, Cheng Hao; Jarry, Angelique; Chen, Wei; Ye, Yifan; Zhu, Junfa; Kostecki, Robert; Persson, Kristin; Guo, Jinghua; Salmeron, Miquel; Chen, Guoying; Doeff, Marca

    2015-08-19

    The interfacial resistances of symmetrical lithium cells containing Al-substituted Li7La3Zr2O12 (LLZO) solid electrolytes are sensitive to their microstructures and histories of exposure to air. Air exposure of LLZO samples with large grain sizes (∼150 μm) results in dramatically increased interfacial impedances in cells containing them, compared to those with pristine large-grained samples. In contrast, a much smaller difference is seen between cells with small-grained (∼20 μm) pristine and air-exposed LLZO samples. A combination of soft X-ray absorption (sXAS) and Raman spectroscopy, with probing depths ranging from nanometer to micrometer scales, revealed that the small-grained LLZO pellets are more air-stable than large-grained ones, forming far less surface Li2CO3 under both short- and long-term exposure conditions. Surface sensitive X-ray photoelectron spectroscopy (XPS) indicates that the better chemical stability of the small-grained LLZO is related to differences in the distribution of Al and Li at sample surfaces. Density functional theory calculations show that LLZO can react via two different pathways to form Li2CO3. The first, more rapid, pathway involves a reaction with moisture in air to form LiOH, which subsequently absorbs CO2 to form Li2CO3. The second, slower, pathway involves direct reaction with CO2 and is favored when surface lithium contents are lower, as with the small-grained samples. These observations have important implications for the operation of solid-state lithium batteries containing LLZO because the results suggest that the interfacial impedances of these devices is critically dependent upon specific characteristics of the solid electrolyte and how it is prepared.

  13. PVC-PBMA nanocomposite polymer electrolytes for lithium battery applications

    Science.gov (United States)

    Arunkumar, R.; Rani, M. Usha; Babu, Ravishanker

    2017-05-01

    Polyvinyl chloride (PVC)-Poly (butyl methacrylate) (PBMA) composite polymer electrolytes with incorporation of different ratio of ZrO2 doped was prepared by solution casting technique. The ionic conductivity, dielectric behavior, ionic transference number and surface morphology of the composite polymer electrolytes were characterized by using ac impedance, dielectric, DC polarization method and SEM studies respectively. The best room temperature ionic conductivity (0.520mScm-1 at 303 K), high dielectric constant (27340 ± 10 at 50 Hz) and high pore size obtained for 10 wt% of ZrO2 doped composite polymer electrolytes. DC polarization method confirms the occurrences of conduction in composite PVC-PBMA blend polymer electrolytes predominantly due to ions.

  14. Sweat output measurement of the post-ganglion sudomotor response by Q-Sweat Test: a normative database of Chinese individuals

    Directory of Open Access Journals (Sweden)

    Chen Shu-Fang

    2012-06-01

    Full Text Available Abstract Background Q-Sweat is a model used for evaluating the post-ganglionic sudomotor function by assessing sweat response. This study aimed to establish the normative database of Q-Sweat test among Chinese individuals since this type of information is currently lacking. Results One hundred and fifty (150 healthy volunteers, 76 men and 74 women with age range of 22–76 years were included. Skin temperature and sweat onset latency measured at the four sites (i.e., the forearm, proximal leg, distal leg, and the foot did not significantly correlate with age, gender, body height (BH, body weight (BW, and body mass index (BMI but the total sweat volume measured in all four sites significantly correlated with sex, BH, and BW. Except for the distal leg, the total sweat volume measured at the other three sites had a significant correlation with BMI. In terms of gender, men had larger total sweat volume, with median differences at the forearm, proximal leg, distal leg, and foot of 0.591 μl, 0.693 μl, 0.696 μl, and 0.358 μl, respectively. Regarding BW difference (≥62 and  Conclusion This is the first report to show the normative database of sweat response in Chinese participants evaluated using Q-Sweat device. This normative database can help guide further research on post-ganglionic sudomotor or related clinical practice involving a Chinese population.

  15. Hydration status, fluid intake, and electrolyte losses in youth soccer players.

    Science.gov (United States)

    Williams, Craig A; Blackwell, Jamie

    2012-12-01

    The purpose of the study was to determine the hydration status, fluid intake, and electrolyte losses of 21 male professional youth soccer players (age 17.1 ± 0.7 y) training in a cool environment. Pretraining and posttraining measurements of body mass, urine (freezing-point osmolality method), and sweat concentration (flame-emission spectroscopy) were collected. Fourteen players were found to be hypohydrated before training. The amount of fluid lost due to exercise equated to a 1.7% loss in body mass, which equated to a gross dehydration loss of 0.5%. Overall, the soccer players replaced 46% ± 88% of sweat loss during training, and only 4 remained hypohydrated after training. No significant correlations between sweat loss and sweat concentrations of Na+ (r = -.11, P = .67) or K+ (r = .14, P = .58) were found, but there was a significant correlation with Mg2+ (r = -.58, P hydration status that the players were able to rehydrate during the training sessions. However, given the numbers starting training in a hypohydrated state, adequate hydration status before training should be considered by youth players, coaches, and sports-science support staff.

  16. Evaluation and review of body fluids saliva, sweat and tear compared to biochemical hydration assessment markers within blood and urine.

    Science.gov (United States)

    Villiger, M; Stoop, R; Vetsch, T; Hohenauer, E; Pini, M; Clarys, P; Pereira, F; Clijsen, R

    2018-01-01

    Evaluating and testing hydration status is increasingly requested by rehabilitation, sport, military and performance-related activities. Besides commonly used biochemical hydration assessment markers within blood and urine, which have their advantages and limitations in collection and evaluating hydration status, there are other potential markers present within saliva, sweat or tear. This literature review focuses on body fluids saliva, sweat and tear compared to blood and urine regarding practicality and hydration status influenced by fluid restriction and/or physical activity. The selected articles included healthy subjects, biochemical hydration assessment markers and a well-described (de)hydration procedure. The included studies (n=16) revealed that the setting and the method of collecting respectively accessing body fluids are particularly important aspects to choose the optimal hydration marker. To obtain a sample of saliva is one of the simplest ways to collect body fluids. During exercise and heat exposures, saliva composition might be an effective index but seems to be highly variable. The collection of sweat is a more extensive and time-consuming technique making it more difficult to evaluate dehydration and to make a statement about the hydration status at a particular time. The collection procedure of tear fluid is easy to access and causes very little discomfort to the subject. Tear osmolarity increases with dehydration in parallel to alterations in plasma osmolality and urine-specific gravity. But at the individual level, its sensitivity has to be further determined.

  17. Human Water and Electrolyte Balance

    National Research Council Canada - National Science Library

    Montain, S. J; Cheuvront, S. N; Carter, R; Sawka, M. N

    2006-01-01

    .... The imposition of exercise and environmental stress can, however, challenge this ability. Most circumstances involving physical exercise require the formation and vaporization of sweat as the principle means of heat removal in man...

  18. A novel organotypic 3D sweat gland model with physiological functionality.

    Directory of Open Access Journals (Sweden)

    Patricia Klaka

    Full Text Available Dysregulated human eccrine sweat glands can negatively impact the quality-of-life of people suffering from disorders like hyperhidrosis. Inability of sweating can even result in serious health effects in humans affected by anhidrosis. The underlying mechanisms must be elucidated and a reliable in vitro test system for drug screening must be developed. Here we describe a novel organotypic three-dimensional (3D sweat gland model made of primary human eccrine sweat gland cells. Initial experiments revealed that eccrine sweat gland cells in a two-dimensional (2D culture lose typical physiological markers. To resemble the in vivo situation as close as possible, we applied the hanging drop cultivation technology regaining most of the markers when cultured in its natural spherical environment. To compare the organotypic 3D sweat gland model versus human sweat glands in vivo, we compared markers relevant for the eccrine sweat gland using transcriptomic and proteomic analysis. Comparing the marker profile, a high in vitro-in vivo correlation was shown. Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5, muscarinic acetylcholine receptor M3 (CHRM3, Na+-K+-Cl- cotransporter 1 (NKCC1, calcium-activated chloride channel anoctamin-1 (ANO1/TMEM16A, and aquaporin-5 (AQP5 are found at significant expression levels in the 3D model. Moreover, cholinergic stimulation with acetylcholine or pilocarpine leads to calcium influx monitored in a calcium flux assay. Cholinergic stimulation cannot be achieved with the sweat gland cell line NCL-SG3 used as a sweat gland model system. Our results show clear benefits of the organotypic 3D sweat gland model versus 2D cultures in terms of the expression of essential eccrine sweat gland key regulators and in the physiological response to stimulation. Taken together, this novel organotypic 3D sweat gland model shows a good in vitro-in vivo correlation and is an appropriate alternative for screening of potential

  19. Sweat fluid and ion losses in horses during training and competition in cool vs. hot ambient conditions: implications for ion supplementation.

    Science.gov (United States)

    McCutcheon, L J; Geor, R J

    1996-07-01

    The objectives of this study were to: 1) determine incremental and total sweat fluid and ion losses during and following (a) exercise training and (b) a treadmill Speed and Endurance exercise test (SEET) which simulated running speeds and distances required for each phase of an Olympic level (CCI****) 3-day-event in cool and hot ambient conditions and 2) determine the requirement for ion supplementation based on the calculated ion losses associated with these activities. Six exercise-trained Thoroughbred horses completed 2 weeks of exercise training in each of 2 ambient conditions: cool, dry (CD, room temperature [T] = 20-22 degrees C, relative humidity [RH] = 45-55%), or hot and humid (HH, T = 33-35 degrees C, RH = 80-85%). Following the 2 week period of training in either CD or HH conditions, horses completed a SEET under similar conditions (either CD, or hot and dry (HD, T = 33-35 degrees C, RH = 45-55%). Sweating rate and sweat ion composition for each 5 min interval was determined from sweat samples collected from a sealed pouch attached to the lateral thorax. Total sweat fluid losses during training in the heat were 2- or 3-fold greater when compared to CD. Similarly, sweat fluid losses associated with the SEET in HD were almost double (19.2 litres) the losses in CD (11.7 litres). Total calculated ion losses associated with 2 h of training in HH (3724 mmol; 115.2 g) were significantly greater when compared to CD (1413 mmol; 43.5 g). Following the SEET and a 30 min recovery period, total ion losses in CD were 3636 mmol (112.2 g) compared with 6519 mmol (200.6 g) in HD. The differences in ion losses represent the increased sweating rates stimulated by higher core temperatures during moderate to high intensity exercise in warmer ambient conditions and increases in sweat ion concentrations associated with higher sweating rates. Extracellular fluid (ECF) ion losses during daily exercise training and the SEET were also calculated from changes in plasma ion

  20. Sweat output measurement of the post-ganglion sudomotor response by Q-Sweat Test: a normative database of Chinese individuals

    Science.gov (United States)

    2012-01-01

    Background Q-Sweat is a model used for evaluating the post-ganglionic sudomotor function by assessing sweat response. This study aimed to establish the normative database of Q-Sweat test among Chinese individuals since this type of information is currently lacking. Results One hundred and fifty (150) healthy volunteers, 76 men and 74 women with age range of 22–76 years were included. Skin temperature and sweat onset latency measured at the four sites (i.e., the forearm, proximal leg, distal leg, and the foot) did not significantly correlate with age, gender, body height (BH), body weight (BW), and body mass index (BMI) but the total sweat volume measured in all four sites significantly correlated with sex, BH, and BW. Except for the distal leg, the total sweat volume measured at the other three sites had a significant correlation with BMI. In terms of gender, men had larger total sweat volume, with median differences at the forearm, proximal leg, distal leg, and foot of 0.591 μl, 0.693 μl, 0.696 μl, and 0.358 μl, respectively. Regarding BW difference (≥62 and sweat volume. Median differences at the forearm, proximal leg, distal leg, and foot were 0.538 μl, 0.744 μl, 0.695 μl, and 0.338 μl, respectively. There was an uneven distribution of male and female participants in the two BW groups. In all conditions, the total sweat volume recorded at the foot site was the smallest. Conclusion This is the first report to show the normative database of sweat response in Chinese participants evaluated using Q-Sweat device. This normative database can help guide further research on post-ganglionic sudomotor or related clinical practice involving a Chinese population. PMID:22682097

  1. Electrolytic refining of gold

    OpenAIRE

    Wohlwill, Emil

    2008-01-01

    At the request of the editor of ELECTROCHEMICAL INDUSTRY, I herewith give some notes on the electrolytic method of gold refining, to supplement the article of Dr. Tuttle (Vol. I, page 157, January, 1903).

  2. Anion exchange polymer electrolytes

    Science.gov (United States)

    Kim, Yu Seung; Kim, Dae Sik

    2015-06-02

    Anion exchange polymer electrolytes that include guanidinium functionalized polymers may be used as membranes and binders for electrocatalysts in preparation of anodes for electrochemical cells such as solid alkaline fuel cells.

  3. Endoscopic lumbar sympathectomy for women: effect on compensatory sweat

    Directory of Open Access Journals (Sweden)

    Marcelo de Paula Loureiro

    2008-01-01

    Full Text Available INTRODUCTION: Plantar hyperhidrosis is present in 50% of patients with hyperhidrosis. Thoracic sympathectomy is an important tool for the treatment of this condition, which is successful in about 60% of patients. For the remaining patients, lumbar sympathectomy is the procedure of choice. As new minimally invasive techniques have been developed, a significant demand for this type of access has led to its adaptation to the lumbar sympathectomy. The objective of this study was to evaluate the effectiveness of endoscopic retroperitoneal lumbar sympathectomy in controlling plantar hyperhidrosis and its effects on compensatory sweat. MATERIALS AND METHODS: Thirty female patients with persistent plantar hyperhidrosis after thoracic sympathectomy were enrolled. They were randomly assigned to laparoscopic retroperitoneal lumbar sympathectomy (Group A or no surgical intervention (Group B - control groups. Quality-of-life modifications were assessed by specific questionnaires before and after surgery. In the same manner, direct sweat measurements were also performed pre- and post-intervention by evaluating trans-epidermal water loss. Despite the lack of intervention, the control group was evaluated at similar timepoints. RESULTS: In Group A, no major complications occurred in the peri-operative period. During the immediate post-operative period, three patients (20% experienced prolonged pain (more than ten days. Eight patients suffered from worsened compensatory sweating (53.3%. In Group A, after lumbar sympathectomy, the quality of life significantly improved (p<0.05, intra-group comparison beyond that of the control group (p<0.05, inter-group comparison. Also, lumbar sympathectomy resulted in significantly lower values of foot sweat (pre- vs. post-operative periods, p<0.05; Group A vs. Group B, p<0.05. These patients also developed higher values of sweat measurements on specific points of their dorsal and abdominal regions after the procedure (p<0

  4. Thermoregulation, Fluid Balance, and Sweat Losses in American Football Players.

    Science.gov (United States)

    Davis, Jon K; Baker, Lindsay B; Barnes, Kelly; Ungaro, Corey; Stofan, John

    2016-10-01

    Numerous studies have reported on the thermoregulation and hydration challenges athletes face in team and individual sports during exercise in the heat. Comparatively less research, however, has been conducted on the American Football player. Therefore, the purpose of this article is to review data collected in laboratory and field studies and discuss the thermoregulation, fluid balance, and sweat losses of American Football players. American Football presents a unique challenge to thermoregulation compared with other sports because of the encapsulating nature of the required protective equipment, large body size of players, and preseason practice occurring during the hottest time of year. Epidemiological studies report disproportionately higher rates of exertional heat illness and heat stroke in American Football compared with other sports. Specifically, larger players (e.g., linemen) are at increased risk for heat ailments compared with smaller players (e.g., backs) because of greater body mass index, increased body fat, lower surface area to body mass ratio, lower aerobic capacity, and the stationary nature of the position, which can reduce heat dissipation. A consistent finding across studies is that larger players exhibit higher sweating rates than smaller players. Mean sweating rates from 1.0 to 2.9 L/h have been reported for college and professional American Football players, with several studies reporting 3.0 L/h or more in some larger players. Sweat sodium concentration of American Football players does not seem to differ from that of athletes in other sports; however, given the high volume of sweat loss, the potential for sodium loss is higher in American Football than in other sports. Despite high sweating rates with American Football players, the observed disturbances in fluid balance have generally been mild (mean body mass loss ≤2 %). The majority of field-based studies have been conducted in the northeastern part of the United States, with limited

  5. Nanoscale Organic Hybrid Electrolytes

    KAUST Repository

    Nugent, Jennifer L.

    2010-08-20

    Nanoscale organic hybrid electrolytes are composed of organic-inorganic hybrid nanostructures, each with a metal oxide or metallic nanoparticle core densely grafted with an ion-conducting polyethylene glycol corona - doped with lithium salt. These materials form novel solvent-free hybrid electrolytes that are particle-rich, soft glasses at room temperature; yet manifest high ionic conductivity and good electrochemical stability above 5V. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Phase composition and fine structure of 0.18C-1Cr-3Ni-1Mo-Fe steel after plasma-electrolytic treatment

    Science.gov (United States)

    Popova, Natalya; Bayatanova, Lyayla; Nikonenko, Elena; Skakov, Mazhyn; Kozlov, Eduard

    2017-01-01

    The paper presents the transmission electron microscopy (TEM) investigation of 0.18C-1Cr-3Mn-1Mo- Fe steel specimens to study phase transitions and modification of fine structure after plasma-electrolytic treatment (carbonitriding at 850°C during 5 min). TEM investigations involve two points: on the specimen surface and at ˜40 µm distance from it. The experiments show that the structure in the original state is a mixture consisting of ferrite and perlite grains. Carbonitriding results in a considerable modification of the quality and quantity of steel structure. Thus, on the surface, α-phase is represented by lamellar martensite, while at ˜40 µm depth - by massive and lamellar martensite tempered at low and high temperatures. Moreover, on the subsurface of the martensite plates' boundaries retained austenite layers are observed, while inside plates the particles of alloyed cementite, carbonitrides of M23(C,N)6, M2C0.61N0.39, M6,2C3,5N0,3, M(C,N)2, Cr12Fe32Mo7Ni7 types, and β-graphite are present. In the specimen at the depth of ˜40 µm, retained austenite layers are observed on the boundaries of martensite laths and plates, while inside plates only the particles of alloyed cementite and M23(C,N)6 carbonitride are formed.

  7. Low temperature solid oxide electrolytes (LT-SOE): A review

    Science.gov (United States)

    Singh, B.; Ghosh, S.; Aich, S.; Roy, B.

    2017-01-01

    Low temperature solid oxide fuel cell (LT-SOFC) can be a source of power for vehicles, online grid, and at the same time reduce system cost, offer high reliability, and fast start-up. A huge amount of research work, as evident from the literature has been conducted for the enhancement of the ionic conductivity of LT electrolytes in the last few years. The basic conduction mechanisms, advantages and disadvantages of different LT oxide ion conducting electrolytes {BIMEVOX systems, bilayer systems including doped cerium oxide/stabilised bismuth oxide and YSZ/DCO}, mixed ion conducting electrolytes {doped cerium oxides/alkali metal carbonate composites}, and proton conducting electrolytes {doped and undoped BaCeO3, BaZrO3, etc.} are discussed here based on the recent research articles. Effect of various material aspects (composition, doping, layer thickness, etc.), fabrication methods (to achieve different microstructures and particle size), design related strategies (interlayer, sintering aid etc.), characterization temperature & environment on the conductivity of the electrolytes and performance of the fuel cells made from these electrolytes are shown in tabular form and discussed. The conductivity of the electrolytes and performance of the corresponding fuel cells are compared. Other applications of the electrolytes are mentioned. A few considerations regarding the future prospects are pointed.

  8. Ionic liquid-nanoparticle hybrid electrolytes

    KAUST Repository

    Lu, Yingying

    2012-01-01

    We investigate physical and electrochemical properties of a family of organic-inorganic hybrid electrolytes based on the ionic liquid 1-methyl-3-propylimidazolium bis(trifluoromethanesulfone) imide covalently tethered to silica nanoparticles (SiO 2-IL-TFSI). The ionic conductivity exhibits a pronounced maximum versus LiTFSI composition, and in mixtures containing 13.4 wt% LiTFSI, the room-temperature ionic conductivity is enhanced by over 3 orders of magnitude relative to either of the mixture components, without compromising lithium transference number. The SiO 2-IL-TFSI/LiTFSI hybrid electrolytes are thermally stable up to 400°C and exhibit tunable mechanical properties and attractive (4.25V) electrochemical stability in the presence of metallic lithium. We explain these observations in terms of ionic coupling between counterion species in the mobile and immobile (particle-tethered) phases of the electrolytes. © 2012 The Royal Society of Chemistry.

  9. Effect of filler content on the properties of expanded- graphite-based composite bipolar plates for application in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Masand, Aakash; Borah, Munu; Pathak, Abhishek K.; Dhakate, Sanjay R.

    2017-09-01

    Minimization of the weight and volume of a hydrogen-based PEM fuel cell stack is an essential area of research for the development and commercialization of PEMFCs for various applications. Graphite-based composite bipolar plates have significant advantages over conventional metallic bipolar plates due to their corrosion resistivity and low cost. On the other hand, expanded graphite is seen to be a potential candidate for facilitating the required electrical, thermal and mechanical properties of bipolar plates with a low density. Therefore, in the present study, the focus is on minimization of the high loading of graphite and optimizes its composition to meet the target properties of bipolar plates as per the USDOE target. Three types of expanded graphite (EG)-phenolic-resin-based composite bipolar plates were developed by partially replacing the expanded graphite content with natural graphite (NG) and carbon black as an additional filler. The three types of composite plate with the reinforcing constituent ratio EG:NG:R (25:25:50) give a bending strength of 49 MPa, a modulus of ~6 GPa, electrical conductivity  >100 S cm-1, a shore hardness of 55 and a bulk density of 1.55 g/cc. The 50 wt% loading of resin is sufficient to wet the 50 wt% filler content in the composite plate. This study gives an insight into using hybrid reinforcements in order to achieve the desired properties of bipolar plates.

  10. Body Odor Trait Disgust Sensitivity Predicts Perception of Sweat Biosamples.

    Science.gov (United States)

    Liuzza, Marco Tullio; Olofsson, Jonas K; Sabiniewicz, Agnieszka; Sorokowska, Agnieszka

    2017-07-01

    Body odors are potent triggers of disgust and regulate social behaviors in many species. The role of olfaction in disgust-associated behaviors has received scant attention in the research literature, in part because olfactory disgust assessments have required laboratory testing with odors. We have devised the "Body Odor Disgust Scale" (BODS) to facilitate research on olfactory disgust. In this study, we evaluated whether individual differences in BODS scores would be associated with the perception of disgust for sweat samples in a laboratory setting. Results show that BODS was a strong predictor of disgust ratings of sweat samples even when controlling for general disgust sensitivity. In contrast, odor intensity ratings were unrelated to BODS scores. Our findings suggest that the BODS scores reflect body odor disgust perception. The BODS scale might facilitate research on olfactory disgust responses and associated behaviors. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Laboratory performance of sweat conductivity for the screening of cystic fibrosis.

    Science.gov (United States)

    Greaves, Ronda F; Jolly, Lisa; Massie, John; Scott, Sue; Wiley, Veronica C; Metz, Michael P; Mackay, Richard J

    2017-10-09

    There are several complementary English-language guidelines for the performance of the sweat chloride test. These guidelines also incorporate information for the collection of conductivity samples. However, recommendations for the measurement and reporting of sweat conductivity are less clear than for sweat chloride. The aim of the study was to develop an understanding of the testing and reporting practices of sweat conductivity in Australasian laboratories. A survey specifically directed at conductivity testing was sent to the 12 laboratories registered with the Royal College of Pathologists of Australasia Quality Assurance Programs. Nine (75%) laboratories participated in the survey, seven of whom used Wescor Macroduct® for collecting sweat and the Wescor SWEAT·CHEK™ for conductivity testing, and the remaining two used the Wescor Nanoduct®. There was considerable variation in frequency and staffing for this test. Likewise, criteria about which patients it was inappropriate to test, definitions of adequate collection sweat rate, cutoffs and actions recommended on the basis of the result showed variations between laboratories. Variations in sweat conductivity testing and reporting reflect many of the same issues that were revealed in sweat chloride test audits and have the potential to lead to uncertainty about the result and the proper action in response to the result. We recommend that sweat testing guidelines should include clearer statements about the use of sweat conductivity.

  12. Coloured sweat in two brothers: First report of familial chromhidrosis.

    Science.gov (United States)

    Gaffney, Daniel C; Cooper, Hywel L

    2016-02-01

    The uncommon diagnosis of chromhidrosis is most frequently made in young adults. This sweat gland disease, although benign, may impact significantly on the patient's quality of life. We describe the first report of familial chromhidrosis of pseudo-eccrine type (pseudochromhidrosis) occurring in two brothers aged 9 and 12 years. The classification and causality of chromhidrosis is described and approaches to assessment and management are outlined. © 2015 The Australasian College of Dermatologists.

  13. Effects of current generation and electrolyte pH on reverse salt flux across thin film composite membrane in osmotic microbial fuel cells.

    Science.gov (United States)

    Qin, Mohan; Abu-Reesh, Ibrahim M; He, Zhen

    2016-11-15

    Osmotic microbial fuel cells (OsMFCs) take advantages of synergy between forward osmosis (FO) and microbial fuel cells (MFCs) to accomplish wastewater treatment, current generation, and high-quality water extraction. As an FO based technology, OsMFCs also encounter reverse salt flux (RSF) that is the backward transport of salt ions across the FO membrane into the treated wastewater. This RSF can reduce water flux, contaminate the treated wastewater, and increase the operational expense, and thus must be properly addressed before any possible applications. In this study, we aimed to understand the effects of current generation and electrolyte pH on RSF in an OsMFC. It was found that electricity generation could greatly inhibit RSF, which decreased from 16.3 ± 2.8 to 3.9 ± 0.7 gMH when the total Coulomb production increased from 0 to 311 C. The OsMFC exhibited 45.9 ± 28.4% lower RSF at the catholyte pH of 3 than that at pH 11 when 40 Ω external resistance was connected. The amount of sodium ions transported across the FO membrane was 18.3-40.7% more than that of chloride ions. Ion transport was accomplished via diffusion and electrically-driven migration, and the theoretical analysis showed that the inhibited electrically-driven migration should be responsible for the reduced RSF. These findings are potentially important to control and reduce RSF in OsMFCs or other osmotic-driven processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Chemical Visualization of Sweat Pores in Fingerprints Using GO-Enhanced TOF-SIMS.

    Science.gov (United States)

    Cai, Lesi; Xia, Meng-Chan; Wang, Zhaoying; Zhao, Ya-Bin; Li, Zhanping; Zhang, Sichun; Zhang, Xinrong

    2017-08-15

    Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been used in imaging of small molecules (600 Da) and controlled drugs, and antibiotics (>700 Da) in fingerprints. Detail features of fingerprints such as the number and distribution of sweat pores in a ridge and even the delicate morphology of one pore were clearly revealed in SIMS images of relatively high mass molecules. The detail features combining with identified chemical composition were sufficient to establish a human identity and link the suspect to a crime scene. The wide detectable mass range and high spatial resolution make GO-enhanced TOF-SIMS a promising tool in accurate and fast analysis of fingerprints, especially in fragmental fingerprint analysis.

  15. The English 'sweate' (Sudor Anglicus) and Hantavirus pulmonary syndrome.

    Science.gov (United States)

    Bridson, E

    2001-01-01

    A rapidly fatal viral infectious disease appeared in England in 1485, persisted for the summer months and disappeared as winter approached. This pattern of infection re-appeared in 1508, 1517, 1528, and finally 1551. The epidemic never returned. It had no respect for wealth or rank, and predominantly attacked males between the ages of 15 and 45 years. The incubation period was frighteningly short and the outcome normally fatal. The symptoms of acute respiratory disease and copious sweating were characteristic, providing the name 'the English sweating disease'. It was never in the big league of killer epidemics, such as plague and influenza, but its pockets of instant lethality in communities gave it a special ranking of horror. The infective cause of this disease remained a total mystery until it was compared with Hantavirus pulmonary syndrome (HPS) in 1994. The strength of this theory is examined in this paper, and it is concluded that, although there is a close resemblance, HPS does not match the English sweating disease completely and positive identification of a possible rodent carrier for the latter was not established.

  16. Anthropometric profile and sweat rate in young soccer players

    Directory of Open Access Journals (Sweden)

    Luciana Rossi

    2009-04-01

    Full Text Available Soccer is a sport whose worldwide acceptance has been growing year after year, and is one of the most important events in the sports world. A growing number of children and teenagers are engaged in this activity, but studies regarding risk factors such as adiposity and negative impacts such as dehydration and hyperthermia are scarce. The aim of this study was to evaluate the anthropometric profile, sweat rate and risk of dehydration among young soccer players. For anthropometric assessment, weight, height, circumference measures and skinfold thickness were collected and used for the determination of body mass index and percent body fat of each player. For determination of the sweat rate, players were weighed before and after pre-competition training. Analysis of fat percentage (14.4 ± 3.6% and the sum of skinfolds showed that the players presented an optimal percentage and activity pattern, probably related to their role in the game. Although low (8.8 ± 6.6 mL/min, the sweat rate varied widely among players, wit the observation of a significant reduction (p<0.05 in final weight. The risk of dehydration was low, but the same cannot be stated for the risk of hyperthermia. Further studies involving this population are necessary to establish an adequate hydration strategy, with emphasis on the monitoring of signs of hyperthermia.

  17. Anthropometric profile and sweat rate in young soccer players

    Directory of Open Access Journals (Sweden)

    Vanessa Aparecida de Brito Reis

    2009-01-01

    Full Text Available http://dx.doi.org/10.5007/1980-0037.2009v11n2p134   Soccer is a sport whose worldwide acceptance has been growing year after year, and is one of the most important events in the sports world. A growing number of children and teenagers are engaged in this activity, but studies regarding risk factors such as adiposity and negative impacts such as dehydration and hyperthermia are scarce. The aim of this study was to evaluate the anthropometric profile, sweat rate and risk of dehydration among young soccer players. For anthropometric assessment, weight, height, circumference measures and skinfold thickness were collected and used for the determination of body mass index and percent body fat of each player. For determination of the sweat rate, players were weighed before and after pre-competition training. Analysis of fat percentage (14.4 ± 3.6% and the sum of skinfolds showed that the players presented an optimal percentage and activity pattern, probably related to their role in the game. Although low (8.8 ± 6.6 mL/min, the sweat rate varied widely among players, wit the observation of a significant reduction (p < 0.05 in final weight. The risk of dehydration was low, but the same cannot be stated for the risk of hyperthermia. Further studies involving this population are necessary to establish an adequate hydration strategy, with emphasis on the monitoring of signs of hyperthermia.

  18. Metastatic apocrine sweat gland adenocarcinoma in a terrier dog.

    Science.gov (United States)

    Baharak, Akhtardanesh; Reza, Kheirandish; Shahriar, Dabiri; Omid, Azari; Daruoosh, Vosoogh; Nasrin, Askari

    2012-08-01

    This report describes the clinical and pathological aspects of an apocrine sweat gland carcinoma with distant metastasis in an aged dog. A 7-year-old male terrier dog was referred to small animal hospital of Shahid Bahonar University of Kerman with a 5.5×3.5 centimeter pedunculated mass on its head near left auricular region which had been progressively growing since three months ago. The radiography showed no local and distant metastasis. Surgical excision and histological evaluation was done. Histologically, the mass was composed of epithelial cells arranged in glandular and solid patterns. The morphologic findings suggested either a primary or metastatic apocrine-gland carcinoma. Immunohistochemically, the tumor cells were intensely positive for cytokeratin 7 and 20 and negative for S100 protein. On the basis of histopathological and clinical findings, the tumor was diagnosed as a malignant apocrine gland tumor, arising from apocrine sweat glands of the skin. Local tumor recurrence with anorexia and weight loss was reported by the owner nine month later. Severe submandibular and prescapular lymphadenomegaly was noted in clinical examination. Several large pulmonary nodules were noted in chest radiographs resembling mediastinal lymph node metastasis. Second surgery and chemotherapy was rejected by the owner due to grave prognosis of the patient. The animal was died 45 days later due to respiratory complications. Tumors of apocrine sweat glands are relatively uncommon in dogs whereas apocrine gland adenocarcinoma with distant metastasis is extremely rare.

  19. Physical properties of molten carbonate electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, T.; Yanagida, M.; Tanimoto, K. [Osaka National Research Institute (Japan)] [and others

    1996-12-31

    Recently many kinds of compositions of molten carbonate electrolyte have been applied to molten carbonate fuel cell in order to avoid the several problems such as corrosion of separator plate and NiO cathode dissolution. Many researchers recognize that the addition of alkaline earth (Ca, Sr, and Ba) carbonate to Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3} and Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} eutectic electrolytes is effective to avoid these problems. On the other hand, one of the corrosion products, CrO{sub 4}{sup 2-} ion is found to dissolve into electrolyte and accumulated during the long-term MCFC operations. This would affect the performance of MCFC. There, however, are little known data of physical properties of molten carbonate containing alkaline earth carbonates and CrO{sub 4}{sup 2-}. We report the measured and accumulated data for these molten carbonate of electrical conductivity and surface tension to select favorable composition of molten carbonate electrolytes.

  20. Electrolytes in the cornea: a therapeutic challenge.

    Science.gov (United States)

    Schrage, N F; Flick, S; Redbrake, C; Reim, M

    1996-12-01

    Reported here are the results of electrolyte measurements in different layers of 70 apparently normal human corneas. Samples were examined by energy-dispersive X-ray analysis under calibrated conditions in a scanning electron microscope. The method allows the simultaneous quantitative analysis of, among others, sodium (Na), chloride (Cl), phosphorus (P) and potassium (K). The results are related to the dry weight of the analyzed samples. Four distinct layers, subepithelium, middle stroma, posterior stroma and Descemet's membrane, were analysed in each cornea. In the middle stroma we found concentrations of: sodium 0.609 +/- 0.13, chloride 0.557 +/- 0.115, potassium 0.058 +/- 0.02 and phosphorus 0.038 +/- 0.01 (mol/kg dry weight) [corrected]. The collation of normal electrolyte concentrations provides reference values for future studies on changes of the corneal electrolyte composition in diseased or injured eyes. The electrolyte composition of rinsing fluids or eye drops should be adjusted to that of the corneal stroma. Phosphate buffer, for example, is not a good vehicle for topical eye treatments and should be replaced by organic buffering systems.

  1. MultiLayer solid electrolyte for lithium thin film batteries

    Science.gov (United States)

    Lee, Se -Hee; Tracy, C. Edwin; Pitts, John Roland; Liu, Ping

    2015-07-28

    A lithium metal thin-film battery composite structure is provided that includes a combination of a thin, stable, solid electrolyte layer [18] such as Lipon, designed in use to be in contact with a lithium metal anode layer; and a rapid-deposit solid electrolyte layer [16] such as LiAlF.sub.4 in contact with the thin, stable, solid electrolyte layer [18]. Batteries made up of or containing these structures are more efficient to produce than other lithium metal batteries that use only a single solid electrolyte. They are also more resistant to stress and strain than batteries made using layers of only the stable, solid electrolyte materials. Furthermore, lithium anode batteries as disclosed herein are useful as rechargeable batteries.

  2. サウスウェル"Christs bloody sweat"におけるSacramental Body(1)

    OpenAIRE

    森, ゆかり

    2000-01-01

    As C.A. Schten pointed out earlier, the Roman Catholic Sacrifice of the Mass is at the center of the poem, "Christs bloody sweat" by Robert Southwell, S.J. (1561-1595). During his formation as a Jesuit, Southwell meditated much on the pains of martyrdom by using the Ignatian composition of place. In Part I of this essay, I will explore how his contemporary Roman Catholic martyrologies shaped his persecutory imagination in preparing his own mission to Protestant England, after explaining some ...

  3. Comfort, measured by means of a sweating manikin (Walter (TM)), of clothing containing different fibre combinations : A preliminary investigation

    CSIR Research Space (South Africa)

    Botha, Anton F

    2016-11-01

    Full Text Available and thickness, wool fabrics were better thermal insulators than the fabrics composed of the other fibres which they tested, whereas, Baxter and Cassie (1943) showed that, for a range of fabrics differing widely in fibre composition and ING MANIKIN (SOURCE... on the sweating fabric manikin WalterTM. REFERENCES ANON, N.D. Walter-Perspiring fabric manikin measurement system Version 3.0: User licence and manual. Polymer Technology & Consulting Company Ltd. BAXTER, S. & CASSIE, A.B.D. 1943. Thermal insulation...

  4. Imaging calcium carbonate distribution in human sweat pore in vivo using nonlinear microscopy

    Science.gov (United States)

    Chen, Xueqin; Gasecka, Alicja; Formanek, Florian; Galey, Jean-Baptiste; Rigneault, Hervé

    2015-03-01

    Nonlinear microscopies, including two-photon excited autofluorescence (TPEF) and coherent anti-Stokes Raman scattering (CARS), were used to study individual human sweat pore morphology and topically applied antiperspirant salt penetration inside sweat pore, in vivo on human palms. Sweat pore inner morphology in vivo was imaged up to the depth of 100 μm by TPEF microscopy. The 3D penetration and distribution of "in situ calcium carbonate" (isCC), an antiperspirant salt model, was investigated using CARS microscopy.

  5. The effect of heat acclimation on sweat microminerals: artifact of surface contamination.

    Science.gov (United States)

    Ely, Matthew R; Kenefick, Robert W; Cheuvront, Samuel N; Chinevere, Troy; Lacher, Craig P; Lukaski, Henry C; Montain, Scott J

    2013-10-01

    Heat acclimation (HA) reportedly conveys conservation in sweat micromineral concentrations when sampled from arm sweat, but time course is unknown. The observation that comprehensive cleaning of the skin surface negates sweat micromineral reductions during prolonged sweating raises the question of whether the reported HA effect is real or artifact of surface contamination. To measure sweat mineral concentrations serially during HA and determine if surface contamination plays a role in the reported mineral reductions. Calcium (Ca), copper (Cu), magnesium (Mg), and zinc (Zn) were measured in sweat obtained from 17 male volunteers using an arm bag on Day 1, 5, and 10 of a HA protocol. To study the role of contamination, sweat was simultaneously (n = 10 subjects) sampled twice daily from a cleaned site (WASH) and unclean site (NO WASH) on the scapular surface. Sweat Ca, Cu, and Mg from Arm Bag trended progressively downward from Day 1 to Day 10 of HA (p = .10-0.25). Micromineral concentrations from the WASH site did not change between Day 1, 5, or 10 (Ca = 0.30 ± 0.12 mmol/L, Cu 0.41 ± 0.53 μmol/L; Zn 1.11 ± 0.80 μmol/L). Surface contamination can confound sweat mineral estimates, as sweat Ca and Cu from NO WASH site were initially higher than WASH (p Heat acclimation does not confer reductions in sweat Ca, Cu, Mg, or Zn. When the skin surface is not cleaned, mineral residue inflates initial sweat mineral concentrations. Earlier reports of micromineral reductions during HA may have been confounded by interday cleaning variability.

  6. Gel electrolytes and electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmann, Sven; Bunte, Christine; Mikhaylik, Yuriy V.; Viner, Veronika G.

    2017-09-05

    Gel electrolytes, especially gel electrolytes for electrochemical cells, are generally described. In some embodiments, the gel electrolyte layers comprise components a) to c). Component a) may be at least one layer of at least one polymer comprising polymerized units of: a1) at least one monomer containing an ethylenically unsaturated unit and an amido group and a2) at least one crosslinker. Component b) may be at least one conducting salt and component c) may be at least one solvent. Electrodes may comprise the components a), d) and e), wherein component a) may be at least one layer of at least one polymer as described herein. Component d) may be at least one electroactive layer and component e) may be at least one ceramic layer. Furthermore, electrochemical cells comprising component a) which may be at least one layer of at least one polymer as described herein, are also provided.

  7. Seebeck effect in electrolytes.

    Science.gov (United States)

    Chikina, I; Shikin, V; Varlamov, A A

    2012-07-01

    We study Seebeck effect in liquid electrolytes, starting from its simple neutral analog--thermodiffusion (so-called Ludwig-Soret or Soret effect). It is observed that when two or more subsystems of mobile particles are subjected to the temperature gradient, various types of them respond to it differently. In the case when these fractions, with different mobility parameters (Soret coefficients), are oppositely charged (a case typical for electrolytes), the nonhomogeneous internal electric field is generated. The latter field prevents these fractions from space separation and determines the intensity of the appearing Seebeck effect.

  8. [Study on sweat gland regeneration induced by microenvironment of three-dimensional bioprinting].

    Science.gov (United States)

    Yao, B; Xie, J F; Huang, S; Fu, X B

    2017-01-20

    Sweat glands are abundant in the body surface and essential for thermoregulation. Sweat glands fail to conduct self-repair in patients with large area of burn and trauma, and the body temperature of patients increases in hot climate, which may cause shock or even death. Now, co-culture system, reprogramming, and tissue engineering have made progresses in inducing sweat gland regeneration, but the inductive efficiency and duration need to be improved. Cellular microenvironment can regulate cell biological behavior, including cell migration and cell differentiation. This article reviews the studies of establishment of microenvironment in vitro by three-dimensional bioprinting technology to induce sweat gland regeneration.

  9. Comparison of fabric skins for the simulation of sweating on thermal manikins

    Science.gov (United States)

    Koelblen, Barbara; Psikuta, Agnes; Bogdan, Anna; Annaheim, Simon; Rossi, René M.

    2017-09-01

    Sweating is an important thermoregulatory process helping to dissipate heat and, thus, to prevent overheating of the human body. Simulations of human thermo-physiological responses in hot conditions or during exercising are helpful for assessing heat stress; however, realistic sweating simulation and evaporative cooling is needed. To this end, thermal manikins dressed with a tight fabric skin can be used, and the properties of this skin should help human-like sweat evaporation simulation. Four fabrics, i.e., cotton with elastane, polyester, polyamide with elastane, and a skin provided by a manikin manufacturer (Thermetrics) were compared in this study. The moisture management properties of the fabrics have been investigated in basic tests with regard to all phases of sweating relevant for simulating human thermo-physiological responses, namely, onset of sweating, fully developed sweating, and drying. The suitability of the fabrics for standard tests, such as clothing evaporative resistance measurements, was evaluated based on tests corresponding to the middle phase of sweating. Simulations with a head manikin coupled to a thermo-physiological model were performed to evaluate the overall performance of the skins. The results of the study showed that three out of four evaluated fabrics have adequate moisture management properties with regard to the simulation of sweating, which was confirmed in the coupled simulation with the head manikin. The presented tests are helpful for comparing the efficiency of different fabrics to simulate sweat-induced evaporative cooling on thermal manikins.

  10. In vivo sweat film layer thickness measured with Fourier-domain optical coherence tomography

    CSIR Research Space (South Africa)

    Jonathan, E

    2008-01-01

    Full Text Available the added advantage of supporting near-real time or video rate imaging speed. Consequently, FD-OCT supports assessment of tissue structure as well as near-real time imaging of functioning small organs in tissue [16–19]. The focus of this paper is direct... accurate measurement of SFL thickness as a diagnostic parameter of sweat intensity while near-real time imaging of the responsible small organs, namely sweat glands, sweat ducts and sweat pores is also of interest. 2. Experimental 2.1. Apparatus OCT...

  11. Low abundance of sweat duct Cl− channel CFTR in both healthy and cystic fibrosis athletes with exceptionally salty sweat during exercise

    Science.gov (United States)

    Haack, Karla K. V.; Pollack, Brian P.; Millard-Stafford, Mindy; McCarty, Nael A.

    2011-01-01

    To understand potential mechanisms explaining interindividual variability observed in human sweat sodium concentration ([Na+]), we investigated the relationship among [Na+] of thermoregulatory sweat, plasma membrane expression of Na+ and Cl− transport proteins in biopsied human eccrine sweat ducts, and basal levels of vasopressin (AVP) and aldosterone. Lower ductal luminal membrane expression of the Cl− channel cystic fibrosis transmembrane conductance regulator (CFTR) was observed in immunofluorescent staining of sweat glands from healthy young adults identified as exceptionally “salty sweaters” (SS) (n = 6, P sweat [Na+] (control, n = 6). Genetic testing of healthy subjects did not reveal any heterozygotes (“carriers”) for any of the 39 most common disease-causing CFTR mutations in the United States. SS had higher baseline plasma [AVP] compared with control (P = 0.029). Immunostaining to investigate a potential relationship between higher plasma [AVP] (and sweat [Na+]) and ductal membrane aquaporin-5 revealed for all groups a relatively sparse and location-dependent ductal expression of the water channel with localization primarily to the secretory coil. Availability of CFTR for NaCl transport across the ductal membrane appears related to the significant physiological variability observed in sweat salt concentration in apparently healthy humans. At present, a heritable link between healthy salty sweaters and the most prevalent disease-causing CFTR mutations cannot be established. PMID:21228336

  12. Determination of the maximum rate of eccrine sweat glands’ ion reabsorption using the galvanic skin conductance to local sweat rate relationship.

    Science.gov (United States)

    Amano, Tatsuro; Gerrett, Nicola; Inoue, Yoshimitsu; Nishiyasu, Takeshi; Havenith, George; Kondo, Narihiko

    2016-02-01

    The purpose of the present study was to develop and describe a simple method to evaluate the rate of ion reabsorption of eccrine sweat glands in human using the measurement of galvanic skin conductance (GSC) and local sweating rate (SR). This purpose was investigated by comparing the SR threshold for increasing GSC with following two criteria of sweat ion reabsorption in earlier studies such as (1) the SR threshold for increasing sweat ion was at approximately 0.2–0.5 mg/cm2/min and (2) exercise heat acclimation improved the sweat ion reabsorption ability and would increase the criteria 1. Seven healthy non-heat-acclimated male subjects received passive heat treatment both before and after 7 days of cycling in hot conditions (50% maximum oxygen uptake, 60 min/day, ambient temperature 32 °C, and 50% relative humidity). Subjects became partially heat-acclimated, as evidenced by the decreased end-exercise heart rate (p rate of perceived exhaustion (p maximum rate of sweat ion reabsorption of eccrine sweat glands in humans.

  13. Electrode-Electrolyte Interfaces in Lithium-Sulfur Batteries with Liquid or Inorganic Solid Electrolytes.

    Science.gov (United States)

    Yu, Xingwen; Manthiram, Arumugam

    2017-11-21

    Electrode-electrolyte interfacial properties play a vital role in the cycling performance of lithium-sulfur (Li-S) batteries. The issues at an electrode-electrolyte interface include electrochemical and chemical reactions occurring at the interface, formation mechanism of interfacial layers, compositional/structural characteristics of the interfacial layers, ionic transport across the interface, and thermodynamic and kinetic behaviors at the interface. Understanding the above critical issues is paramount for the development of strategies to enhance the overall performance of Li-S batteries. Liquid electrolytes commonly used in Li-S batteries bear resemblance to those employed in traditional lithium-ion batteries, which are generally composed of a lithium salt dissolved in a solvent matrix. However, due to a series of unique features associated with sulfur or polysulfides, ether-based solvents are generally employed in Li-S batteries rather than simply adopting the carbonate-type solvents that are generally used in the traditional Li+-ion batteries. In addition, the electrolytes of Li-S batteries usually comprise an important additive, LiNO3. The unique electrolyte components of Li-S batteries do not allow us to directly take the interfacial theories of the traditional Li+-ion batteries and apply them to Li-S batteries. On the other hand, during charging/discharging a Li-S battery, the dissolved polysulfide species migrate through the battery separator and react with the Li anode, which magnifies the complexity of the interfacial problems of Li-S batteries. However, current Li-S battery development paths have primarily been energized by advances in sulfur cathodes. Insight into the electrode-electrolyte interfacial behaviors has relatively been overshadowed. In this Account, we first examine the state-of-the-art contributions in understanding the solid-electrolyte interphase (SEI) formed on the Li-metal anode and sulfur cathode in conventional liquid-electrolyte Li

  14. The electrolytic plating of compositionally modulated alloys and laminated metal nano-structures based on an automated computer-controlled dual-bath system

    DEFF Research Database (Denmark)

    NabiRahni, D.M.A.; Tang, Peter Torben; Leisner, Peter

    1996-01-01

    applications reported in the literature. Until recently, however, producing such multilayered coatings has been difficult at best, especially for larger samples of irregular configuration and in mass production. We will explain the design, objective and the use of our newly developed automated computer....... Employing the automated dual-bath technique, multilayered composite materials of copper-nickel and copper-cobalt with more than 1000 alternating layers of varying dimensions, if desired, have been investigated and manufactured. The thickness of each sub-layer ranges from 25 nm to several micrometres (mu m...

  15. Electrolyte Volume Effects on Electrochemical Performance and Solid Electrolyte Interphase in Si-Graphite/NMC Lithium-Ion Pouch Cells.

    Science.gov (United States)

    An, Seong Jin; Li, Jianlin; Daniel, Claus; Meyer, Harry M; Trask, Stephen E; Polzin, Bryant J; Wood, David L

    2017-06-07

    This study aims to explore the correlations between electrolyte volume, electrochemical performance, and properties of the solid electrolyte interphase in pouch cells with Si-graphite composite anodes. The electrolyte is 1.2 M LiPF6 in ethylene carbonate:ethylmethyl carbonate with 10 wt % fluoroethylene carbonate. Single layer pouch cells (100 mA h) were constructed with 15 wt % Si-graphite/LiNi0.5Mn0.3CO0.2O2 electrodes. It is found that a minimum electrolyte volume factor of 3.1 times to the total pore volume of cell components (cathode, anode, and separator) is needed for better cycling stability. Less electrolyte causes increases in ohmic and charge transfer resistances. Lithium dendrites are observed when the electrolyte volume factor is low. The resistances from the anodes become significant as the cells are discharged. Solid electrolyte interphase thickness grows as the electrolyte volume factor increases and is nonuniform after cycling.

  16. Ion-Chain Dynamics in Polymer Electrolytes

    OpenAIRE

    Carlos, L. D.; Videira, A. L. L.

    1996-01-01

    Representing polyether-salt systems by chains of interacting coordination shells, defined by the cation and by its nearest ligands, we derive the interaction potential between closest shells -- the inter-shells potential -- in terms of two-electron polarization effects. Values are presented for monovalent-based crystalline poly(ethylene oxide), PEO, electrolytes. For the eutectic composition $\\text{PEO}_{12} \\text{EuBr}_3$, the inter-shells energy is evaluated also by relating the empirical v...

  17. Plasma electrolytic oxidation of Titanium Aluminides

    Science.gov (United States)

    Morgenstern, R.; Sieber, M.; Grund, T.; Lampke, T.; Wielage, B.

    2016-03-01

    Due to their outstanding specific mechanical and high-temperature properties, titanium aluminides exhibit a high potential for lightweight components exposed to high temperatures. However, their application is limited through their low wear resistance and the increasing high-temperature oxidation starting from about 750 °C. By the use of oxide ceramic coatings, these constraints can be set aside and the possible applications of titanium aluminides can be extended. The plasma electrolytic oxidation (PEO) represents a process for the generation of oxide ceramic conversion coatings with high thickness. The current work aims at the clarification of different electrolyte components’ influences on the oxide layer evolution on alloy TNM-B1 (Ti43.5Al4Nb1Mo0.1B) and the creation of compact and wear resistant coatings. Model experiments were applied using a ramp-wise increase of the anodic potential in order to show the influence of electrolyte components on the discharge initiation and the early stage of the oxide layer growth. The production of PEO layers with technically relevant thicknesses close to 100 μm was conducted in alkaline electrolytes with varying amounts of Na2SiO3·5H2O and K4P2O7 under symmetrically pulsed current conditions. Coating properties were evaluated with regard to morphology, chemical composition, hardness and wear resistance. The addition of phosphates and silicates leads to an increasing substrate passivation and the growth of compact oxide layers with higher thicknesses. Optimal electrolyte compositions for maximum coating hardness and thickness were identified by statistical analysis. Under these conditions, a homogeneous inner layer with low porosity can be achieved. The frictional wear behavior of the compact coating layer is superior to a hard anodized layer on aluminum.

  18. Halogen acid electrolysis in solid polymer electrolyte cells

    Energy Technology Data Exchange (ETDEWEB)

    Balko, E.N.; McElroy, J.F.; LaConti, A.B.

    1981-01-01

    The use of solid polymer electrolyte systems has been extended to the electrolysis of aqueous HCl and HBr. The reduced internal losses in these cells permits the production of hydrogen and the halogen at an energy consumption considerably less than that reported previously. Data are presented for the operational characteristics of the solid polymer electrolyte acid electrolysers operating over a range of current densities, pressures, feedstock compositions, and temperatures.

  19. Spin coating of electrolytes

    Science.gov (United States)

    Stetter, Joseph R.; Maclay, G. Jordan

    1989-01-01

    Methods for spin coating electrolytic materials onto substrates are disclosed. More particularly, methods for depositing solid coatings of ion-conducting material onto planar substrates and onto electrodes are disclosed. These spin coating methods are employed to fabricate electrochemical sensors for use in measuring, detecting and quantifying gases and liquids.

  20. Sweat patterns differ between tilt-induced reflex syncope and tilt-induced anxiety among youth.

    Science.gov (United States)

    Heyer, Geoffrey L; Harvey, Rebecca A; Islam, Monica P

    2016-08-01

    Profound sweating can occur with reflex-syncope and with emotional distress, but little is known about the similarities and differences between these sweat responses when they occur during orthostatic challenge. We sought to characterize and compare the sweat patterns related to tilt-induced syncope, presyncope, anxiety, and normal tilt testing. In a prospective observational study, quantitative sweat rate was measured from the abdomen, forearm, ankle, and thigh during head-upright tilt. Sweat characteristics were compared across tilt diagnoses of syncope, presyncope, anxiety, and normal testing. When anxiety and syncope/presyncope occurred during the same study (separated by ≥6 min), both were diagnosed. Our cohort comprised150 patients (15.1 ± 2.3 years; 82.9 % female) with 156 diagnoses: 76 with reflex-syncope, 31 with presyncope, 23 with anxiety, and 26 with normal results. All syncope/presyncope patients and 20 (87 %) of the anxiety patients had corresponding sweat responses. Minimal or negligible sweating occurred among patients with normal tests. Neither basal sweat (19.4 ± 4.7 versus 18.3 ± 3.7 versus 18.5 ± 3.7 nL/min/cm(2)) nor peak sweat (171 ± 47.4 versus 149.4 ± 64.4 versus 154.4 ± 59.2 nL/min/cm(2)) differed between patients with syncope, presyncope, or anxiety, p = .32 and p = .12, respectively. However, the qualitative sweat patterns related to syncope/presyncope (diffuse, smoothly contoured, symmetrical, single peaks) differed considerably from the sweat patterns related to anxiety (heterogeneous, asymmetrical, roughly contoured single-peak, multi-peak, or progressive sweat changes). The sweat patterns related to syncope/presyncope are distinguishable from the sweat patterns related to anxiety. Recognition of the different sweat patterns can inform how signs and symptoms are interpreted during clinical orthostatic challenge.

  1. Fungal protein MGL_1304 in sweat is an allergen for atopic dermatitis patients.

    Science.gov (United States)

    Hiragun, Takaaki; Ishii, Kaori; Hiragun, Makiko; Suzuki, Hidenori; Kan, Takanobu; Mihara, Shoji; Yanase, Yuhki; Bartels, Joachim; Schröder, Jens-M; Hide, Michihiro

    2013-09-01

    Sweat is a major aggravating factor of atopic dermatitis (AD) and approximately 80% of patients with AD show type I hypersensitivity against sweat. To identify and characterize an antigen in sweat that induces histamine release from basophils of patients with AD. Basophil histamine-releasing activity in sweat was purified by a combination of chromatographies, and proteins were analyzed with mass spectrometry. Recombinant proteins of the sweat antigen were generated, and their biological characteristics were studied by immunoblots, histamine release tests, and neutralization assays. We identified a fungal protein, MGL_1304, derived from Malassezia globosa (M globosa) in the purified sweat antigen. Recombinant MGL_1304 induced histamine release from basophils of most of the patients with AD, in accordance with the semi-purified sweat antigen. Moreover, recombinant MGL_1304 abolished the binding of serum IgE of patients with AD to the semi-purified sweat antigen, or vice versa in immunoblot analysis, and attenuated the sensitization of RBL-48 mast cells expressing human FcɛRI by serum IgE. Studies of truncated mutants of MGL_1304 indicated that IgE of patients with AD recognized the conformational structure of MGL_1304 rather than short peptide sequences. Western blot analysis of the whole lysate, the culture supernatant of M globosa, and the semi-purified sweat antigen showed that MGL_1304 was produced as a minor immunological antigen of M globosa with posttranslational modification, cleaved, and secreted as a 17-kDa major histamine-releasing sweat antigen. MGL_1304 is a major allergen in human sweat and could cause type I allergy in patients with AD. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  2. Evaluating performance in sweat testing in medical biochemistry laboratories in Croatia.

    Science.gov (United States)

    Aralica, Merica; Krleza, Jasna Lenicek

    2017-02-15

    Sweat test has a diagnostic role in evaluation of cystic fibrosis. Its performance includes sweat stimulation, collection and analysis. All listed may be sources of inconsistencies in everyday practice. The aim of this study was an evaluation of external quality assessment (EQA) of sweat chloride measurement including sweat test performance in medical biochemistry laboratories in Croatia. EQA for sweat chloride measurement was provided by Croatian Centre for Quality Assessment in Laboratory Medicine (CROQALM) in five consecutive exercises to medical biochemistry laboratories (MBL) that offered sweat testing. A questionnaire regarding all phases of testing was mailed to involved MBL (N = 10). Survey results were compared to current guidelines for sweat test performance. Reported results of EQA in 2015 exercises showed coefficients of variation (CV) from 28.9%, 29.0% to 35.3%, respectively. An introduction of uniform sweat chloride measurement protocol resulted in CV of 15.5% and 14.7% reported in following two exercises in 2016. All MBL included in this study replied to the questionnaire. Results reported by MBL indicated: lack of patient information policy (7/10), use of unacceptable electrodes (6/9), misuse of minimum of acceptable sweat weight (6/9), lack of internal quality assessment (5/9) and recommended reference ranges (5/9 and 4/9). Agreements to guidelines were found in approach to unsuitable patients (9/10) and sweat collection (8/9). Presented results indicate major weak points of current practice in sweat test performance in Croatian MBL and stress the need for its standardization on a national level.

  3. Metastatic apocrine sweat gland adenocarcinoma in a terrier dog

    OpenAIRE

    Baharak, Akhtardanesh; Reza, Kheirandish; Shahriar, Dabiri; Omid, Azari; Daruoosh, Vosoogh; Nasrin, Askari

    2012-01-01

    This report describes the clinical and pathological aspects of an apocrine sweat gland carcinoma with distant metastasis in an aged dog. A 7-year-old male terrier dog was referred to small animal hospital of Shahid Bahonar University of Kerman with a 5.5×3.5 centimeter pedunculated mass on its head near left auricular region which had been progressively growing since three months ago. The radiography showed no local and distant metastasis. Surgical excision and histological evaluation was don...

  4. Gel polymer electrolytes for batteries

    Science.gov (United States)

    Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William

    2014-11-18

    Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at 25.degree. C.

  5. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

    DEFF Research Database (Denmark)

    2001-01-01

    A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes...... electrolyte membrane by hot-press. The fuel cell can operate at temperatures up to at least 200 °C with hydrogen-rich fuel containing high ratios of carbon monoxide such as 3 vol% carbon monoxide or more, compared to the carbon monoxide tolerance of 10-20 ppm level for Nafion$m(3)-based polymer electrolyte...

  6. Comparison of Quantitative Sweat Chloride Methods after Positive Newborn Screen for Cystic Fibrosis

    Science.gov (United States)

    Laguna, Theresa A.; Lin, Nan; Wang, Qi; Holme, Bonnie; McNamara, John; Regelmann, Warren E.

    2013-01-01

    Summary Objectives Rapid and reliable confirmatory sweat testing following a positive newborn screen (NBS) for cystic fibrosis (CF) is preferred to allow for early diagnosis and to decrease parental anxiety. The Cystic Fibrosis Foundation (CFF) recently recommended a quantity not sufficient (QNS) rate of ≤ 10% in infants sweat chloride analysis. Two CFF-approved methods are available by which to quantitatively measure chloride concentration in sweat. Our objective was to compare the performance of the Macroduct® sweat collection system (MSCS) with the Gibson and Cooke technique (GCT) in the acquisition of samples for the determination of sweat chloride concentration in infants with a positive Minnesota State NBS for cystic fibrosis. Methods A retrospective database review of infants referred to the core Minnesota CF Center or its affiliate site for confirmatory sweat testing was performed to compare the QNS rates for the two techniques. Associations between birthweight, age at test, race and QNS rates were examined. Results 568 infants were referred for 616 sweat tests from March 2006–January 2010. The mean age was 32.8 days at the initial sweat test. The GCT had a significantly higher QNS rate compared to the MSCS (15.4% vs. 2.1%, psweat testing in infants following a positive state NBS. PMID:22786625

  7. Sweat : Materiality and Fluidity of Perspiration in in Eighteenth-Century Medicine

    NARCIS (Netherlands)

    Verwaal, Ruben

    2015-01-01

    How can a bodily excretion like sweat, often accompanied with a stench or associated with anxiety and distress, enrich our view of the history of science? This paper argues that following the fluid and flow of sweat has in fact particular advantages, because it provides a unique perspective by

  8. Lactate and ammonia concentration in blood and sweat during incremental cycle ergometer exercise

    NARCIS (Netherlands)

    Ament, W; Huizenga, [No Value; Mook, GA; Gips, CH; Verkerke, GJ

    It is known that the concentrations of ammonia and lactate in blood increase during incremental exercise. Sweat also contains lactate and ammonia. The aim of the present study was to investigate the physiological response of lactate and ammonia in plasma and sweat during a stepwise incremental cycle

  9. The microfluidics of the eccrine sweat gland, including biomarker partitioning, transport, and biosensing implications

    Science.gov (United States)

    Sonner, Z.; Wilder, E.; Heikenfeld, J.; Kasting, G.; Beyette, F.; Swaile, D.; Sherman, F.; Joyce, J.; Hagen, J.; Kelley-Loughnane, N.; Naik, R.

    2015-01-01

    Non-invasive and accurate access of biomarkers remains a holy grail of the biomedical community. Human eccrine sweat is a surprisingly biomarker-rich fluid which is gaining increasing attention. This is especially true in applications of continuous bio-monitoring where other biofluids prove more challenging, if not impossible. However, much confusion on the topic exists as the microfluidics of the eccrine sweat gland has never been comprehensively presented and models of biomarker partitioning into sweat are either underdeveloped and/or highly scattered across literature. Reported here are microfluidic models for eccrine sweat generation and flow which are coupled with review of blood-to-sweat biomarker partition pathways, therefore providing insights such as how biomarker concentration changes with sweat flow rate. Additionally, it is shown that both flow rate and biomarker diffusion determine the effective sampling rate of biomarkers at the skin surface (chronological resolution). The discussion covers a broad class of biomarkers including ions (Na+, Cl−, K+, NH4+), small molecules (ethanol, cortisol, urea, and lactate), and even peptides or small proteins (neuropeptides and cytokines). The models are not meant to be exhaustive for all biomarkers, yet collectively serve as a foundational guide for further development of sweat-based diagnostics and for those beginning exploration of new biomarker opportunities in sweat. PMID:26045728

  10. The detection of cortisol in human sweat: implications for measurement of cortisol in hair.

    Science.gov (United States)

    Russell, Evan; Koren, Gideon; Rieder, Michael; Van Uum, Stan H M

    2014-02-01

    Hair cortisol analysis has been shown to be an effective measure of chronic stress. Cortisol is assumed to incorporate into hair via serum, sebum, and sweat sources; however, the extent to which sweat contributes to hair cortisol content is unknown. Sweat and saliva samples were collected from 17 subjects after a period of intensive exercise and analyzed by salivary enzyme-linked immunosorbent assay (ELISA). Subsequently, an in vitro test on exposure of hair to hydrocortisone was conducted. Residual hair samples were immersed in a 50-ng/mL hydrocortisone solution for periods lasting 15 minutes to 24 hours, followed by a wash or no-wash condition. Hair cortisol content was determined using our modified protocol for a salivary ELISA. Postexercise control sweat cortisol concentrations ranged from 8.16 to 141.7 ng/mL and correlated significantly with the log-transformed time of day. Sweat cortisol levels significantly correlated with salivary cortisol concentrations. In vitro hair exposure to a 50-ng/mL hydrocortisone solution (mimicking sweat) for 60 minutes or more resulted in significantly increased hair cortisol concentrations. Washing with isopropanol did not affect immersion-increased hair cortisol concentrations. Human sweat contains cortisol in concentrations comparable with salivary cortisol levels. This study suggests that perfuse sweating after intense exercise may increase cortisol concentrations detected in hair. This increase likely cannot be effectively decreased with conventional washing procedures and should be considered carefully in studies using hair cortisol as a biomarker of chronic stress.

  11. A Simple and Valid Method to Determine Thermoregulatory Sweating Threshold and Sensitivity

    Science.gov (United States)

    2009-01-01

    therefore, preferred for sweating threshold temperature and sensitivity analysis (32). Volunteers spit into a cup during data collection to avoid spurious...MA, Stephenson LA. Control of sweating during the human menstrual cycle. Eur J Appl Physiol 58: 890–895, 1989. 21. Kondo N, Shibasaki M, Aoki K, Koga

  12. Biological Variation of Chloride and Sodium in Sweat Obtained by Pilocarpine Iontophoresis in Adults: How Sure are You About Sweat Test Results?

    Science.gov (United States)

    Willems, Philippe; Weekx, Steven; Meskal, Anissa; Schouwers, Sofie

    2017-04-01

    The measurement of chloride and sodium concentrations in sweat is an important test for the diagnosis of cystic fibrosis (CF). The aim of this study was to assess the analytical variation (CV A ) and within-subject (CV I ) and between-subject (CV G ) biological variation of chloride and sodium concentrations in sweat, collected by pilocarpine iontophoresis and to determine their effect on the clinical interpretation of sweat test results. Twelve Caucasian adults (six male and six female) without symptoms suggestive for CF and with a mean age of 41 years (range 28-59) were included in the study. At least eight samples of sweat were collected from each individual by pilocarpine iontophoresis. Chloride and sodium concentrations were measured in duplicate for each sample using ion selective electrodes. After the removal of outliers, the CV A , CV I , and CV G of chloride and sodium were determined, and their impact on measurement uncertainty and reference change value were calculated. The CV A , CV I , and CV G of chloride in sweat samples were 6.5, 17.7, and 47.2%, respectively. The CV A , CV I , and CV G of sodium sweat samples were 6.0, 17.5, and 42.6%, respectively. Our study indicates that sweat chloride and sodium concentration results must be interpreted with great care. Different components of variation, particularly the biological variations, have a considerable impact on the interpretation of these results. If no pre-analytical, analytical, or post-analytical errors are suspected, repeated sweat testing to confirm first-measurement results might not be desirable.

  13. Immunological multimetal deposition for rapid visualization of sweat fingerprints.

    Science.gov (United States)

    He, Yayun; Xu, Linru; Zhu, Yu; Wei, Qianhui; Zhang, Meiqin; Su, Bin

    2014-11-10

    A simple method termed immunological multimetal deposition (iMMD) was developed for rapid visualization of sweat fingerprints with bare eyes, by combining the conventional MMD with the immunoassay technique. In this approach, antibody-conjugated gold nanoparticles (AuNPs) were used to specifically interact with the corresponding antigens in the fingerprint residue. The AuNPs serve as the nucleation sites for autometallographic deposition of silver particles from the silver staining solution, generating a dark ridge pattern for visual detection. Using fingerprints inked with human immunoglobulin G (hIgG), we obtained the optimal formulation of iMMD, which was then successfully applied to visualize sweat fingerprints through the detection of two secreted polypeptides, epidermal growth factor and lysozyme. In comparison with the conventional MMD, iMMD is faster and can provide additional information than just identification. Moreover, iMMD is facile and does not need expensive instruments. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Corrosion behavior of nickel-containing alloys in artificial sweat.

    Science.gov (United States)

    Randin, J P

    1988-07-01

    The corrosion resistance of various nickel-containing alloys was measured in artificial sweat (perspiration) using the Tafel extrapolation method. It was found that Ni, CuNi 25 (coin alloy), NiAl (colored intermetallic compounds), WC + Ni (hard metal), white gold (jewelry alloy), FN42 and Nilo Alby K (controlled expansion alloys), and NiP (electroless nickel coating) are in an active state and dissolve readily in oxygenated artificial sweat. By contrast, austenitic stainless steels, TiC + Mo2C + Ni (hard metal), NiTi (shape-memory alloy), Hastelloy X (superalloy), Phydur (precipitation hardening alloy), PdNi and SnNi (nickel-containing coatings) are in a passive state but may pit under certain conditions. Cobalt, Cr, Ti, and some of their alloys were also investigated for the purpose of comparison. Cobalt and its alloys have poor corrosion resistance except for Stellite 20. Chromium and high-chromium ferritic stainless steels have a high pitting potential but the latter are susceptible to crevice corrosion. Ti has a pitting potential greater than 3 V. Comparison between the in vitro measurements of the corrosion rate of nickel-based alloys and the clinical observation of the occurrence of contact dermatitis is discussed.

  15. Nanoporous hybrid electrolytes

    KAUST Repository

    Schaefer, Jennifer L.

    2011-01-01

    Oligomer-suspended SiO2-polyethylene glycol nanoparticles are studied as porous media electrolytes. At SiO2 volume fractions, , bracketing a critical value y ≈ 0.29, the suspensions jam and their mechanical modulus increase by more than seven orders. For >y, the mean pore diameter is close to the anion size, yet the ionic conductivity remains surprisingly high and can be understood, at all , using a simple effective medium model proposed by Maxwell. SiO 2-polyethylene glycol hybrid electrolytes are also reported to manifest attractive electrochemical stability windows (0.3-6.3 V) and to reach a steady-state interfacial impedance when in contact with metallic lithium. © 2010 The Royal Society of Chemistry.

  16. LOW TEMPERATURE CATHODE SUPPORTED ELECTROLYTES

    Energy Technology Data Exchange (ETDEWEB)

    Harlan U. Anderson

    2000-03-31

    This project has three main goals: Thin Films Studies, Preparation of Graded Porous Substrates and Basic Electrical Characterization and Testing of Planar Single Cells. During this time period substantial progress has been made in developing low temperature deposition techniques to produce dense, nanocrystalline yttrium-stabilized zirconia films on both dense oxide and polymer substrates. Progress has been made in the preparation and characterization of thin electrolytes and porous LSM substrates. Both of these tasks are essentially on or ahead of schedule. In our proposal, we suggested that the ZrO{sub 2}/Sc system needed to be considered as a candidate as a thin electrolyte. This was because microcrystalline ZrO{sub 2}/Sc has a significantly higher ionic conductivity than YSZ, particularly at the lower temperatures. As a result, some 0.5 micron thick film of ZrO{sub 2}/16% Sc on an alumina substrate (grain size 20nm) was prepared and the electrical conductivity measured as a function of temperature and oxygen activity. The Sc doped ZrO{sub 2} certainly has a higher conductivity that either 20nm or 2400nm YSZ, however, electronic conductivity dominates the conductivity for oxygen activities below 10{sup -15}. Whereas for YSZ, electronic conductivity is not a problem until the oxygen activity decreases below 10{sup -25}. These initial results show that the ionic conductivity of 20nm YSZ and 20nm ZrO{sub 2}/16% Sc are essentially the same and the enhanced conductivity which is observed for Sc doping in microcrystalline specimens is not observed for the same composition when it is nanocrystalline. In addition they show that the electronic conductivity of Sc doped ZrO{sub 2} is at least two orders of magnitude higher than that observed for YSZ. The conclusion one reaches is that for 0.5 to 1 micron thick nanocrystalline films, Sc doping of ZrO{sub 2} has no benefits compared to YSZ. As a result, electrolyte films of ZrO{sub 2}/Sc should not be considered as candidates

  17. Solid polymer electrolytes

    Science.gov (United States)

    Abraham, Kuzhikalail M.; Alamgir, Mohamed; Choe, Hyoun S.

    1995-01-01

    This invention relates to Li ion (Li.sup.+) conductive solid polymer electrolytes composed of poly(vinyl sulfone) and lithium salts, and their use in all-solid-state rechargeable lithium ion batteries. The lithium salts comprise low lattice energy lithium salts such as LiN(CF.sub.3 SO.sub.2).sub.2, LiAsF.sub.6, and LiClO.sub.4.

  18. Ice electrode electrolytic cell

    Science.gov (United States)

    Glenn, D.F.; Suciu, D.F.; Harris, T.L.; Ingram, J.C.

    1993-04-06

    This invention relates to a method and apparatus for removing heavy metals from waste water, soils, or process streams by electrolytic cell means. The method includes cooling a cell cathode to form an ice layer over the cathode and then applying an electric current to deposit a layer of the heavy metal over the ice. The metal is then easily removed after melting the ice. In a second embodiment, the same ice-covered electrode can be employed to form powdered metals.

  19. Non-electrolytic microelectroporation.

    Science.gov (United States)

    Lyu, Chenang; Wang, Jianping; Rubinsky, Boris

    2017-09-01

    Micro and nano technologies are of increasing importance in microfluidics devices used for electroporation (electroporation - the permeabilization of the cell membrane with brief high electric field pulses). Electrochemical reactions of electrolysis occur whenever an electric current flows between an electrode and an ionic solution. It can have substantial detrimental effects, both on the cells and solutions during the electroporation. As electrolysis is a surface phenomenon, between electrodes and solution, the extent of electrolysis is increased in micro and nano electroporation over macro-electroporation, because the surface area of the electrodes in micro and nano electroporation is much larger. A possible way to eliminate the electrolytic effect is to develop non-electrolytic microelectroporation by coating the microelectroporation devices with a dielectric insulating layer. In this study, we examine the effect of a dielectric insulating layer on the performance of a singularity microelectroporation device that we have recently designed. Using numerical analysis, we study the effects of various design parameters including, input sinusoidal voltage amplitude and frequency, geometrical configuration and material electrical properties on the electroporation performance of the non-electrolytic microelectroporation device. In the simulation, we used properties of four real dielectric materials and four solutions of interest for microelectroporation. We characterized the effect of various design parameters of relevance to singularity based microelectroporation, on non-electrolytic microelectroporation. Interestingly, we found that the system behaves in some aspects as a filter and in many circumstances saturation of performance is reached. After saturation is reached, changes in parameters will not affect the performance of the device.

  20. Electrochemical polymer electrolyte membranes

    CERN Document Server

    Fang, Jianhua; Wilkinson, David P

    2015-01-01

    Electrochemical Polymer Electrolyte Membranes covers PEMs from fundamentals to applications, describing their structure, properties, characterization, synthesis, and use in electrochemical energy storage and solar energy conversion technologies. Featuring chapters authored by leading experts from academia and industry, this authoritative text: Discusses cutting-edge methodologies in PEM material selection and fabricationPoints out important challenges in developing PEMs and recommends mitigation strategies to improve PEM performanceAnalyzes the cur

  1. Electrolyte Concentrates Treat Dehydration

    Science.gov (United States)

    2009-01-01

    Wellness Brands Inc. of Boulder, Colorado, exclusively licensed a unique electrolyte concentrate formula developed by Ames Research Center to treat and prevent dehydration in astronauts returning to Earth. Marketed as The Right Stuff, the company's NASA-derived formula is an ideal measure for athletes looking to combat dehydration and boost performance. Wellness Brands also plans to expand with products that make use of the formula's effective hydration properties to help treat conditions including heat stroke, altitude sickness, jet lag, and disease.

  2. Sweat-inducing physiological challenges do not result in acute changes in hair cortisol concentrations.

    Science.gov (United States)

    Grass, Juliane; Kirschbaum, Clemens; Miller, Robert; Gao, Wei; Steudte-Schmiedgen, Susann; Stalder, Tobias

    2015-03-01

    Hair cortisol concentrations (HCC) are assumed to provide a stable, integrative marker of long-term systemic cortisol secretion. However, contrary to this assumption, some recent observations have raised the possibility that HCC may be subject to acute influences, potentially related to cortisol incorporation from sweat. Here, we provide a first detailed in vivo investigation of this possibility comprising two independent experimental studies: study I (N=42) used a treadmill challenge to induce sweating together with systemic cortisol reactivity while in study II (N=52) a sauna bathing challenge induced sweating without systemic cortisol changes. In both studies, repeated assessments of HCC, salivary cortisol, cortisol in sweat and individuals' sweating rate (single assessment) were conducted on the experimental day and at a next-day follow-up. Results across the two studies consistently revealed that HCC were not altered by the acute interventions. Further, HCC were found to be unrelated to acute salivary cortisol reactivity, sweat cortisol levels, sweating rate or the time of examination. In line with previous data, cortisol levels in sweat were strongly related to total salivary cortisol output across the examined periods. The present results oppose recent case report data by showing that single sweat-inducing interventions do not result in acute changes in HCC. Our data also tentatively speak against the notion that cortisol in sweat may be a dominant source of HCC. Further, our findings also indicate that HCC are not subject to diurnal variation. This research provides further support for hair cortisol analysis as a marker of integrated long-term systemic cortisol secretion. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Attitudes about Advances in Sweat Patch Testing in Drug Courts: Insights from a Case Study in Southern California

    Science.gov (United States)

    Polzer, Katherine

    2010-01-01

    Drug courts are reinventing the drug testing framework by experimenting with new methods, including use of the sweat patch. The sweat patch is a band-aid like strip used to monitor drug court participants. The validity and reliability of the sweat patch as an effective testing method was examined, as well as the effectiveness, meaning how likely…

  4. High performance MCFC using Li/Na electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Donado, R.A.; Ong, E.T.; Sishtla, C.I.

    1995-08-01

    The substitution of a lithium/ sodium carbonate (Li/Na) mixture for the lithium/potassium carbonate (Li/K) electrolyte used in MCFCs holds the promise of higher ionic conductivity, higher exchange current density at both electrodes, lower vapor pressure, and lower cathode dissolution rates. However, when the substitution is made in cells optimized for use with the Li/K electrolyte, the promised increase in performance is not realized. As a consequence the literature contains conflicting data with regard to the performance, compositional stability, and chemical reactivity of the Li/Na electrolyte. Experiments conducted at the Institute of Gas Technology (IGT) concluded that the source of the problem is the different wetting characteristics of the two electrolytes. Electrode pore structures optimized for use with Li/K do not work well with Li/Na. Using proprietary methods and materials, IGT was able to optimize a set of electrodes for the Li/Na electrolyte. Experiments conducted in bench-scale cells have confirmed the superior performance of the Li/Na electrolyte compared to the Li/K electrolyte. The Li/Na cells exhibited a 5 to 8 percent improvement in overall performance, a substantial decrease in the rate of cathode dissolution, and a decreased decay rate. The longest running cell has logged over 13,000 hours of operation with a decay rate of less than 2 mV/1000 hours.

  5. Wetting of Nano-Confined Electrodes By Lithium-Ion Battery Electrolytes Using Multiple Beam Interferometry

    OpenAIRE

    Moeremans, Boaz; Cheng, Hsiu-Wei; Garces, Hector; Padture, Nitin; Hardy, An; Renner, Frank Uwe; Valtiner, Markus

    2015-01-01

    The interface with the electrolyte is a decisive feature in the design of composite battery electrodes, which typically contain active material particles, conductive material, and polymer binder. A detailed understanding of the electrolyte layering and wetting of materials such as graphene, graphites, metals such as aluminum or even gold, silicon, and metal oxides are ultimately important for improving crucial lithium-ion battery mechanisms. In particular the solid electrolyte interphase (SEI...

  6. Eccrine Sweat Contains IL-1α, IL-1β and IL-31 and Activates Epidermal Keratinocytes as a Danger Signal

    Science.gov (United States)

    Dai, Xiuju; Okazaki, Hidenori; Hanakawa, Yasushi; Murakami, Masamoto; Tohyama, Mikiko; Shirakata, Yuji; Sayama, Koji

    2013-01-01

    Eccrine sweat is secreted onto the skin's surface and is not harmful to normal skin, but can exacerbate eczematous lesions in atopic dermatitis. Although eccrine sweat contains a number of minerals, proteins, and proteolytic enzymes, how it causes skin inflammation is not clear. We hypothesized that it stimulates keratinocytes directly, as a danger signal. Eccrine sweat was collected from the arms of healthy volunteers after exercise, and levels of proinflammatory cytokines in the sweat were quantified by ELISA. We detected the presence of IL-1α, IL-1β, and high levels of IL-31 in sweat samples. To investigate whether sweat activates keratinocytes, normal human keratinocytes were stimulated with concentrated sweat. Western blot analysis demonstrated the activation of NF-κB, ERK, and JNK signaling in sweat-stimulated keratinocytes. Real-time PCR using total RNA and ELISA analysis of supernatants showed the upregulation of IL-8 and IL-1β by sweat. Furthermore, pretreatment with IL-1R antagonist blocked sweat-stimulated cytokine production and signal activation, indicating that bioactive IL-1 is a major factor in the activation of keratinocytes by sweat. Moreover, IL-31 seems to be another sweat stimulator that activates keratinocytes to produce inflammatory cytokine, CCL2. Sweat is secreted onto the skin's surface and does not come into contact with keratinocytes in normal skin. However, in skin with a defective cutaneous barrier, such as atopic dermatitis-affected skin, sweat cytokines can directly act on epidermal keratinocytes, resulting in their activation. In conclusion, eccrine sweat contains proinflammatory cytokines, IL-1 and IL-31, and activates epidermal keratinocytes as a danger signal. PMID:23874436

  7. Eccrine sweat contains IL-1α, IL-1β and IL-31 and activates epidermal keratinocytes as a danger signal.

    Directory of Open Access Journals (Sweden)

    Xiuju Dai

    Full Text Available Eccrine sweat is secreted onto the skin's surface and is not harmful to normal skin, but can exacerbate eczematous lesions in atopic dermatitis. Although eccrine sweat contains a number of minerals, proteins, and proteolytic enzymes, how it causes skin inflammation is not clear. We hypothesized that it stimulates keratinocytes directly, as a danger signal. Eccrine sweat was collected from the arms of healthy volunteers after exercise, and levels of proinflammatory cytokines in the sweat were quantified by ELISA. We detected the presence of IL-1α, IL-1β, and high levels of IL-31 in sweat samples. To investigate whether sweat activates keratinocytes, normal human keratinocytes were stimulated with concentrated sweat. Western blot analysis demonstrated the activation of NF-κB, ERK, and JNK signaling in sweat-stimulated keratinocytes. Real-time PCR using total RNA and ELISA analysis of supernatants showed the upregulation of IL-8 and IL-1β by sweat. Furthermore, pretreatment with IL-1R antagonist blocked sweat-stimulated cytokine production and signal activation, indicating that bioactive IL-1 is a major factor in the activation of keratinocytes by sweat. Moreover, IL-31 seems to be another sweat stimulator that activates keratinocytes to produce inflammatory cytokine, CCL2. Sweat is secreted onto the skin's surface and does not come into contact with keratinocytes in normal skin. However, in skin with a defective cutaneous barrier, such as atopic dermatitis-affected skin, sweat cytokines can directly act on epidermal keratinocytes, resulting in their activation. In conclusion, eccrine sweat contains proinflammatory cytokines, IL-1 and IL-31, and activates epidermal keratinocytes as a danger signal.

  8. PREDICTING WATER ACTIVITY IN ELECTROLYTE SOLUTIONS WITH THE CISTERNAS-LAM MODEL

    Energy Technology Data Exchange (ETDEWEB)

    REYNOLDS JG; GREER DA; DISSELKAMP RL

    2011-03-01

    Water activity is an important parameter needed to predict the solubility of hydrated salts in Hanford nuclear waste supernatants. A number of models available in the scientific literature predict water activity from electrolyte solution composition. The Cisternas-Lam model is one of those models and has several advantages for nuclear waste application. One advantage is that it has a single electrolyte specific parameter that is temperature independent. Thus, this parameter can be determined from very limited data and extrapolated widely. The Cisternas-Lam model has five coefficients that are used for all aqueous electrolytes. The present study aims to determine if there is a substantial improvement in making all six coefficients electrolyte specific. The Cisternas-Lam model was fit to data for six major electrolytes in Hanford nuclear waste supernatants. The model was first fit to all data to determine the five global coefficients, when they were held constant for all electrolytes it yielded a substantially better fit. Subsequently, the model was fit to each electrolyte dataset separately, where all six coefficients were allowed to be electrolyte specific. Treating all six coefficients as electrolyte specific did not make sufficient difference, given the complexity of applying the electrolyte specific parameters to multi-solute systems. Revised water specific parameters, optimized to the electrolytes relevant to Hanford waste, are also reported.

  9. Sweat gland tumor (Eccrine Porocarcinoma of scalp: A rare tumor

    Directory of Open Access Journals (Sweden)

    Rana Roshani

    2005-01-01

    Full Text Available Eccrine Porocarcinoma is a rare neoplasm arising from sweat glands. It was first described by Pinkus and Mehregan as ′Epidermotropic eccrine carcinoma′. It may occur de novo or as a malignant transformation of an eccrine poroma. It is commonly found in older age group and in the lower extremities. Clinically, it may present as a verrucous plaque, polypoid growth or an ulcerative lesion of long duration. Local recurrence and metastasis to skin, lymphnodes, viscera, and bone may occur. Treatment is wide local excision. Metastatic lesions can be treated with chemotherapy. We report a case of eccrine porocarcinoma of the scalp in a 50 years old female who presented to us with a bosselated, firm, painless, non-tender, freely mobile swelling over left fronto-parietal region of 12 years duration. It was excised and histopathological diagnosis was Eccrine Porocarcinoma. In literature, scalp porocarcinoma is a very rare tumor.

  10. A Proteomic Analysis of Eccrine Sweat: Implications for the Discovery of Schizophrenia Biomarker Proteins

    Science.gov (United States)

    Raiszadeh, Michelle M.; Ross, Mark M.; Russo, Paul S.; Schaepper, Mary Ann H.; Zhou, Weidong; Deng, Jianghong; Ng, Daniel; Dickson, April; Dickson, Cindy; Strom, Monica; Osorio, Carolina; Soeprono, Thomas; Wulfkuhle, Julia D.; Kabbani, Nadine; Petricoin, Emanuel F.; Liotta, Lance A.; Kirsch, Wolff M.

    2012-01-01

    Liquid chromatography tandem mass spectrometry (LC-MS/MS) and multiple reaction monitoring mass spectrometry (MRM-MS) proteomics analyses were performed on eccrine sweat of healthy controls, and the results were compared with those from individuals diagnosed with schizophrenia (SZ). This is the first large scale study of the sweat proteome. First, we performed LC-MS/MS on pooled SZ samples and pooled control samples for global proteomics analysis. Results revealed a high abundance of diverse proteins and peptides in eccrine sweat. Most of the proteins identified from sweat samples were found to be different than the most abundant proteins from serum, which indicates that eccrine sweat is not simply a plasma transudate, and may thereby be a source of unique disease-associated biomolecules. A second independent set of patient and control sweat samples were analyzed by LC-MS/MS and spectral counting to determine qualitative protein differential abundances between the control and disease groups. Differential abundances of selected proteins, initially determined by spectral counting, were verified by MRM-MS analyses. Seventeen proteins showed a differential abundance of approximately two-fold or greater between the SZ pooled sample and the control pooled sample. This study demonstrates the utility of LC-MS/MS and MRM-MS as a viable strategy for the discovery and verification of potential sweat protein disease biomarkers. PMID:22256890

  11. [Cholinergic urticaria successfully treated by immunotherapy with partially purified sweat antigen].

    Science.gov (United States)

    Tanaka, Toshihiko; Ishii, Kaori; Suzuki, Hidenori; Kameyoshi, Yoshikazu; Hide, Michihiro

    2007-01-01

    A 24-years-old man was referred to our University Hospital because of one and a half-year history of disabling symptoms related to physical exertion. Multiple small round-shaped wheals with severe itch were induced by exercise, warmth and psychological stress. These symptoms were resistant to histamine H1-receptor antagonists. Similar eruptions were induced by sauna-bathing, and skin test with autologous sweat showed a flare and wheal reaction. Incubation of his peripheral-blood leukocytes with partially purified sweat antigen evoked marked histamine release, indicating that he has been IgE-sensitized to an antigen(s) in human sweat. Specific immunotherapy using partially purified sweat antigen was performed every other week. Both pruritus and wheals improved gradually, and the reactivity of his peripheral blood leukocytes against sweat antigen decreased as immunotherapy was proceeded. Specific immunotherapy using sweat antigen may be valuable for patients with cholinergic urticaria with type I hypersensitivity to sweat antigen(s).

  12. SWEAT: Snow Water Equivalent with AlTimetry

    Science.gov (United States)

    Agten, Dries; Benninga, Harm-Jan; Diaz Schümmer, Carlos; Donnerer, Julia; Fischer, Georg; Henriksen, Marie; Hippert Ferrer, Alexandre; Jamali, Maryam; Marinaci, Stefano; Mould, Toby JD; Phelan, Liam; Rosker, Stephanie; Schrenker, Caroline; Schulze, Kerstin; Emanuel Telo Bordalo Monteiro, Jorge

    2017-04-01

    To study how the water cycle changes over time, satellite and airborne remote sensing missions are typically employed. Over the last 40 years of satellite missions, the measurement of true water inventories stored in sea and land ice within the cryosphere have been significantly hindered by uncertainties introduced by snow cover. Being able to determine the thickness of this snow cover would act to reduce such error, improving current estimations of hydrological and climate models, Earth's energy balance (albedo) calculations and flood predictions. Therefore, the target of the SWEAT (Snow Water Equivalent with AlTimetry) mission is to directly measure the surface Snow Water Equivalent (SWE) on sea and land ice within the polar regions above 60°and below -60° latitude. There are no other satellite missions currently capable of directly measuring SWE. In order to achieve this, the proposed mission will implement a novel combination of Ka- and Ku-band radioaltimeters (active microwave sensors), capable of penetrating into the snow microstructure. The Ka-band altimeter (λ ≈ 0.8 cm) provides a low maximum snow pack penetration depth of up to 20 cm for dry snow at 37 GHz, since the volume scattering of snow dominates over the scattering caused by the underlying ice surface. In contrast, the Ku-band altimeter (λ ≈ 2 cm) provides a high maximum snowpack penetration depth of up to 15 m in high latitudes regions with dry snow, as volume scattering is decreased by a factor of 55. The combined difference in Ka- and Ku-band signal penetration results will provide more accurate and direct determination of SWE. Therefore, the SWEAT mission aims to improve estimations of global SWE interpreted from passive microwave products, and improve the reliability of numerical snow and climate models.

  13. Extraction of Carbon Dioxide and Hydrogen from Seawater By an Electrolytic Cation Exchange Module (E-CEM) Part 5: E-CEM Effluent Discharge Composition as a Function of Electrode Water Composition

    Science.gov (United States)

    2017-08-01

    composition and flowrate. These evaluations have identified additional software and hardware capabilities that will be included in in the prototype skid to...ensure E-CEM performance and operational safety while maintaining effluent water quality . 01-08-2017 Memorandum Report Unclassified Unlimited iii...additional software and hardware capabilities that will be included in the prototype skid to ensure E-CEM performance and operational safety while

  14. A Preliminary Study of Biomonitoring for Bisphenol-A in Human Sweat.

    Science.gov (United States)

    Porucznik, Christina A; Cox, Kyley J; Wilkins, Diana G; Anderson, David J; Bailey, Nicole M; Szczotka, Kathryn M; Stanford, Joseph B

    2015-09-01

    Measurement of human exposure to the endocrine disruptor bisphenol-A (BPA) is hampered by the ubiquitous but transient exposure for most individuals, coupled with a short metabolic half-life which leads to high inter- and intra-individual variability. We investigated the possibility of measuring multiday exposure to BPA in human sweat among volunteer participants with the goal of identifying an exposure assessment method less affected by temporal variability. We recruited 50 participants to wear a sweat collection patch (PharmChek(®)) for 7 days with concurrent collection of daily first-morning urine. Urines and sweat patch extracts were analyzed with quantitative LC-MS-MS using a method we previously validated. In addition, a human volunteer consumed one can of commercially available soup (16 oz, 473 cm(3)) daily for 3 days and collected urine. Sweat patches (n = 2, 1 per arm) were worn for the 3 days of the study. BPA was detected in quality control specimens prepared by fortification of BPA to sweat patches, but was only detected at 5× above average background on three participant patches. Although the highest measured urine BPA concentration was 195 ng/mL for an individual with deliberate exposure, no BPA was detected above background in the corresponding sweat patches. In this preliminary investigation, the use of sweat patches primarily worn on the upper-outer arm did not detect BPA exposures that were documented by urine monitoring. The absence of BPA in sweat patches may be due to several factors, including insufficient quantity of specimen per patch, or extremely low concentrations of BPA in naturally occurring sweat, among others. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Transition duration of ingested deuterium oxide to eccrine sweat during exercise in the heat.

    Science.gov (United States)

    Church, Adam; Lee, Fanny; Buono, Michael J

    2017-01-01

    The time necessary for the initial appearance of ingested water as sweat during exercise in the heat remains unknown. Based on the current literature, we estimated fluid transition through the body, from ingestion to appearance as sweat, to have a minimum time duration of approximately three minutes. The purpose of this study was to test this prediction and identify the time necessary for the initial enrichment of deuterium oxide (D2O) in sweat following ingestion during exercise in the heat. Eight participants performed moderate intensity (40% of maximal oxygen uptake) treadmill exercise in an environmental chamber (40°C, 40% rH) to induce active sweating. After fifteen minutes, while continuing to walk, participants consumed D2O (0.15mlkg-1) in a final volume of 50ml water. Scapular sweat samples were collected one minute prior to and ten minutes post-ingestion. Samples were analyzed for sweat D2O concentration using isotope ratio mass spectrometry and compared to baseline. Mean±SD ∆ sweat D2O concentration at minutes one and two post-ingestion were not significantly higher than baseline (0min). Minutes three (9±3ppm) through ten (23±11ppm) post-ingestion had ∆ sweat D2O concentrations significantly (P<0.05) higher than baseline. Such results suggest that ingested water rapidly transports across the mucosal membrane of the alimentary canal into the vasculature space, enters the extravascular fluid, and is actively secreted by the eccrine sweat glands onto the surface of the skin for potential evaporation in as little as three minutes during exercise in the heat. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Accumulation of 2H2O in plasma and eccrine sweat during exercise-heat stress.

    Science.gov (United States)

    Armstrong, Lawrence E; Klau, Jennifer F; Ganio, Matthew S; McDermott, Brendon P; Yeargin, Susan W; Lee, Elaine C; Maresh, Carl M

    2010-02-01

    The purpose of this research was to characterize the movement of ingested water through body fluids, during exercise-heat stress. Deuterium oxide ((2)H(2)O) accumulation in plasma and eccrine sweat was measured at two sites (back and forehead). The exercise of 14 males was controlled via cycle ergometry in a warm environment (60 min; 28.7 degrees C, 51%rh). Subjects consumed (2)H(2)O (0.15 mg kg(-1), 99.9% purity) mixed in flavored, non-caloric, colored water before exercise, then consumed 3.0 ml kg(-1) containing no (2)H(2)O every 15 min during exercise. We hypothesized that water transit from mouth to skin would occur before 15 min. (2)H(2)O appeared rapidly in both plasma and sweat (P deuterium accumulation (DeltaD:H min(-1)) in plasma was 14.9 and 23.7 times greater than in forehead and back sweat samples, respectively. Mean (+/-SE) whole-body sweat rate was 1.04 +/- 0.05 L h(-1) and subjects with the greatest whole-body sweat rate exhibited the greatest peak deuterium enrichment in sweat (r(2) = 0.87, exponential function); the peak (2)H(2)O enrichment in sweat was not proportional (P > 0.05) to body mass, volume of the deuterium dose, or total volume of fluid consumed. These findings clarify the time course of fluid movement from mouth to eccrine sweat glands, and demonstrate considerable differences of (2)H(2)O enrichment in plasma versus sweat.

  17. Evaluation of apatite silicates as solid oxide fuel cell electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Marrero-Lopez, D. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain); Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Martin-Sedeno, M.C.; Aranda, M.A.G. [Dpto. de Quimica Inorganica, Universidad Malaga, 29071 Malaga (Spain); Pena-Martinez, J. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Instituto de Energias Renovables, Parque Tecnologico, Universidad de Castilla La Mancha, 02006 Albacete (Spain); Ruiz-Morales, J.C.; Nunez, P. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Ramos-Barrado, J.R. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain)

    2010-05-01

    Apatite-type silicates have been considered as promising electrolytes for Solid Oxide Fuel Cells (SOFC); however studies on the potential use of these materials in SOFC devices have received relatively little attention. The lanthanum silicate with composition La{sub 10}Si{sub 5.5}Al{sub 0.5}O{sub 26.75} has been evaluated as electrolyte with the electrode materials commonly used in SOFC, i.e. manganite, ferrite and cobaltite as cathode materials and NiO-CGO composite, chromium-manganite and Sr{sub 2}MgMoO{sub 6} as anode materials. Chemical compatibility, area-specific resistance and fuel cell studies have been performed. X-ray powder diffraction (XRPD) analysis did not reveal any trace of reaction products between the apatite electrolyte and most of the aforementioned electrode materials. However, the area-specific polarisation resistance (ASR) of these electrodes in contact with apatite electrolyte increased significantly with the sintering temperature, indicating reactivity at the electrolyte/electrode interface. On the other hand, the ASR values are significantly improved using a ceria buffer layer between the electrolyte and electrode materials to prevent reactivity. Maximum power densities of 195 and 65 mWcm{sup -2} were obtained at 850 and 700 C, respectively in H{sub 2} fuel, using an 1 mm-thick electrolyte, a NiO-Ce{sub 0.8}Gd{sub 0.2}O{sub 1.9} composite as anode and La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} as cathode materials. This fuel cell was tested for 100 h in 5%H{sub 2}-Ar atmosphere showing stable performance. (author)

  18. [Sweat chloride measurement using direct potentiometry: Spotchem(®) (Elitech-Arkray) evaluation and comparison with coulometry and conductivity].

    Science.gov (United States)

    Nguyen-Khoa, Thao; Borgard, Jean-Pierre; Miled, Ryad; Rota, Michèle

    2013-01-01

    Sweat chloride (Cl(-)) measurement is a key step for the diagnosis of cystic fibrosis. The coulometric technique is validated in this context by international guidelines. The aim of our study was to evaluate the assay for sweat Cl(-) ions using direct potentiometry on disposable cassette (Spotchem™ SE EL-1520, Elitech-Arkray) by comparing results to those obtained on the same sample, by coulometry (Chloride analyser Sherwood 926S, Dutscher). To complete our table of correspondence between the results of Cl(-) ions and sweat conductivity (Sweat Check™ 3100), conductivity has been also achieved for 99 of the 139 sweat samples studied. Linearity of each technique performed extends from 10 to 120 mmol/L. The coefficients of variation within and between runs are Sweat Cl(-) determinations using Spotchem™ analyser meet the criteria required by analytical recommendations. The technique is standardized, easy to perform and fast. Its good practicability makes the sweat test independent to operator and allows point-of care use.

  19. The response of the malaria mosquito, Anopheles gambiae, to two components of human sweat, ammonia and L-lactic acid, in an olfactometer

    NARCIS (Netherlands)

    Braks, M.A.H.; Meijerink, J.; Takken, W.

    2001-01-01

    In an olfactometer study on the response of the anthropophilic malaria mosquito Anopheles gambiae s.s. (Diptera, Culicidae) to human sweat it was found that freshly collected sweat, mostly of eccrine origin, was attractive, but that incubated sweat was significantly more attractive than fresh sweat.

  20. Pulsed direct and constant direct currents in the pilocarpine iontophoresis sweat chloride test.

    Science.gov (United States)

    Gomez, Carla Cristina Souza; Servidoni, Maria de Fatima; Marson, Fernando Augusto de Lima; Canavezi, Paulo Jose Coelho; Vinagre, Adriana Mendes; Costa, Eduardo Tavares; Ribeiro, Antonio Fernando; Ribeiro, Maria Angela Gonçalves de Oliveira; Toro, Adyleia Aparecida Dalbo Contrera; Pavan, Celia Regina; Rondon, Michelle Vivine Sá Dos Santos; Lorena, Sonia Leticia Silva; Vieria, Francisco Ubaldi; Ribeiro, Jose Dirceu

    2014-12-13

    The classic sweat test (CST) is the golden standard for cystic fibrosis (CF) diagnosis. Then, our aim was compare the production and volume of sweat, and side effects caused by pulsed direct current (PDC) and constant direct current (CDC). To determine the optimal stimulation time (ST) for the sweat collection. To verify the PDC as CF diagnosis option. Prospective study with cross-sectional experimental intervention. Experiment 1 (right arm): PDC and CDC. ST at 10 min and sweat collected at 30 min. Currents of 0.5; 0.75; 1.0 and 1.5 mA and frequencies of 0, 200, 1,000 and 5,000 Hz applied. Experiment 2 (left arm): current of 1.0 mA, ST at 5 and 10 min and sweat collected at 15 and 30 min with frequencies of 0; 200; 1,000 and 5,000 Hz applied Experiments 1 and 2 were performed with current density (CD) from 0.07 to 0.21 mA/cm2. Experiment 3: PDC was used in typical CF patients with two CFTR mutations screened and or with CF diagnosis by rectal biopsy and patients with atypical CF. 48 subjects (79.16% female) with average of 29.54 ± 8.87 years old were enrolled. There was no statistical difference between the interaction of frequency and current in the sweat weight (p = 0.7488). Individually, positive association was achieved between weight sweat and stimulation frequency (p = 0.0088); and current (p = 0.0025). The sweat production was higher for 10 min of stimulation (p = 0.0023). The sweat collection was better for 30 min (p = 0.0019). The skin impedance was not influenced by ST and sweat collection (p > 0.05). The current frequency was inversely associated with the skin impedance (p sweat, without side effects. The optimal stimulation time and sweat collection were, respectively, 10 and 30 min.

  1. Wearable sweat detector device design for health monitoring and clinical diagnosis

    Science.gov (United States)

    Wu, Qiuchen; Zhang, Xiaodong; Tian, Bihao; Zhang, Hongyan; Yu, Yang; Wang, Ming

    2017-06-01

    Miniaturized sensor is necessary part for wearable detector for biomedical applications. Wearable detector device is indispensable for online health care. This paper presents a concept of an wearable digital health monitoring device design for sweat analysis. The flexible sensor is developed to quantify the amount of hydrogen ions in sweat and skin temperature in real time. The detection system includes pH sensor, temperature sensor, signal processing module, power source, microprocessor, display module and so on. The sweat monitoring device is designed for sport monitoring or clinical diagnosis.

  2. Analysis of methamphetamine in hair, nail, sweat, and saliva by mass fragmentography.

    Science.gov (United States)

    Suzuki, S; Inoue, T; Hori, H; Inayama, S

    1989-01-01

    A method for the detection and quantitation of methamphetamine and its major metabolite in hair, nails, sweat, and saliva from habitual users of methamphetamine by mass fragmentography has been developed. Hair and nail samples were washed with water and methanol to remove the external contamination, processed with 0.6M HCl, alkalinized, and extracted with CHCl3/isopropanol (3:1 v/v). Sweat and saliva samples were extracted with methanol. After trifluoroacetyl derivatization, the samples were analyzed by mass fragmentography. Methamphetamine and its major metabolite, amphetamine, were detected in hair, nail, and sweat samples, but methamphetamine alone was detected in saliva samples.

  3. The fluid and electrolyte balance of New Zealand European and Māori/Pacific Island athletes: An observational study.

    Science.gov (United States)

    McLean, Andrew; Brown, Rachel Clare; Black, Katherine Elizabeth

    2016-01-01

    Observational research on professional athletes from the USA suggests differences may exist in sweat sodium loss based on ethnic differences. The New Zealand (NZ) sporting population is mainly of European or Māori/Pacific Island origin. Therefore, this study aimed to describe the fluid-electrolyte balance of athletes by ethnicity. A total of 20 Māori/Pacific Islanders (MP; body mass 100.97 ± 13.05 kg) and 29 NZ European (NZE; body mass 89.11 ± 11.56 kg) elite male athletes were recruited. Sweat rates were determined by body mass change during a 1-h spin cycle exercise session, during which fluid intakes and heart rate were recorded. Sweat samples were analysed for sodium concentration. Mean ± SD sweat sodium concentrations were 73.4 ± 27.2 mmol·L(-1) and 55.5 ± 26.8 mmol·L(-1) for the MP and NZE groups, respectively (p = 0.070). Sweat rate was 0.93 ± 0.26 L·h(-1) for the MP group and 0.89 ± 0.33 L·h(-1) for the NZE group (p = 0.357). Fluid intake was 1.05 ± 0.48 L and 0.93 ± 0.49 L for MP and NZE, respectively (p = 0.395). Half of the MP group gained weight during the exercise session compared to 37% of the NZE group. Pre-exercise urine specific gravity was significantly lower amongst the NZE group (1.016 ± 0.009 g mL(-1)) than the MP group (1.024 ± 0.008 g mL(-1)) p = 0.001. There was no significant difference in heart rate between the groups, p = 0.082. Hydration practices of athletes in NZ may differ by ethnicity, and this may highlight the need for more targeted education by ethnicity.

  4. Conductivity study of PEO–LiClO4 polymer electrolyte doped with ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. The preparation and characterization of composite polymer electrolytes comprising PEO and. LiClO4 with different concentrations of ZnO nanoparticles are studied. Conductivity measurements were carried out and discussed. In order to ascertain the thermal stability of the polymer electrolyte with maximum.

  5. Conductivity study of PEO–LiClO4 polymer electrolyte doped with ...

    Indian Academy of Sciences (India)

    The preparation and characterization of composite polymer electrolytes comprising PEO and LiClO4 with different concentrations of ZnO nanoparticles are studied. Conductivity measurements were carried out and discussed. In order to ascertain the thermal stability of the polymer electrolyte with maximum conductivity, films ...

  6. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound/video files will in some cases only provide a few minutes' sample, or the visuals will not appear at all...

  7. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2011-01-01

    Strategies are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full...

  8. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2010-01-01

    New Year is an open composition to be realised by improvising musicians. It is included in "From the Danish Seasons" (see under this title). See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You...

  9. Composition

    DEFF Research Database (Denmark)

    2014-01-01

    Memory Pieces are open compositions to be realised solo by an improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them...

  10. Self-Passivating Lithium/Solid Electrolyte/Iodine Cells

    Science.gov (United States)

    Bugga, Ratnakumar; Whitcare, Jay; Narayanan, Sekharipuram; West, William

    2006-01-01

    Robust lithium/solid electrolyte/iodine electrochemical cells that offer significant advantages over commercial lithium/ iodine cells have been developed. At room temperature, these cells can be discharged at current densities 10 to 30 times those of commercial lithium/iodine cells. Moreover, from room temperature up to 80 C, the maximum discharge-current densities of these cells exceed those of all other solid-electrolyte-based cells. A cell of this type includes a metallic lithium anode in contact with a commercial flexible solid electrolyte film that, in turn, is in contact with an iodine/ graphite cathode. The solid electrolyte (the chemical composition of which has not been reported) offers the high ionic conductivity needed for high cell performance. However, the solid electrolyte exhibits an undesirable chemical reactivity to lithium that, if not mitigated, would render the solid electrolyte unsuitable for use in a lithium cell. In this cell, such mitigation is affected by the formation of a thin passivating layer of lithium iodide at the anode/electrolyte interface. Test cells of this type were fabricated from iodine/graphite cathode pellets, free-standing solid-electrolyte films, and lithium-foil anodes. The cathode mixtures were made by grinding together blends of nominally 10 weight percent graphite and 90 weight percent iodine. The cathode mixtures were then pressed into pellets at 36 kpsi (248 MPa) and inserted into coin-shaped stainless-steel cell cases that were coated with graphite paste to minimize corrosion. The solid-electrolyte film material was stamped to form circular pieces to fit in the coin cell cases, inserted in the cases, and pressed against the cathode pellets with polyethylene gaskets. Lithium-foil anodes were placed directly onto the electrolyte films. The layers described thus far were pressed and held together by stainless- steel shims, wave springs, and coin cell caps. The assembled cells were then crimped to form hermetic seals

  11. Hindered Glymes for Graphite-Compatible Electrolytes.

    Science.gov (United States)

    Shanmukaraj, Devaraj; Grugeon, Sylvie; Laruelle, Stephane; Armand, Michel

    2015-08-24

    Organic carbonate mixtures are used almost exclusively as lithium battery electrolyte solvents. The linear compounds (dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate) act mainly as thinner for the more viscous and high-melting ethylene carbonate but are the least stable component and have low flash points; these are serious handicaps for lifetime and safety. Polyethers (glymes) are useful co-solvents, but all formerly known representatives solvate Li(+) strongly enough to co-intercalate in the graphite negative electrode and exfoliate it. We have put forward a new electrolyte composition comprising a polyether to which a bulky tert-butyl group is attached ("hindered glyme"), thus completely preventing co-intercalation while maintaining good conductivity. This alkyl-carbonate-free electrolyte shows remarkable cycle efficiency of the graphite electrode, not only at room temperature, but also at 50 and 70 °C in the presence of lithium bis(fluorosulfonimide). The two-ethylene-bridge hindered glyme has a high boiling point and a flash point of 80 °C, a considerable advantage for safety. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Structure analysis of the membrane-bound dermcidin-derived peptide SSL-25 from human sweat.

    Science.gov (United States)

    Mühlhäuser, Philipp; Wadhwani, Parvesh; Strandberg, Erik; Bürck, Jochen; Ulrich, Anne S

    2017-12-01

    SSL-25 (SSLLEKGLDGAKKAVGGLGKLGKDA) is one of the shortest peptides present in human sweat and is produced after the proteolytic processing of the parent peptide dermcidin. Both peptides are reported to have antimicrobial function. To determine the structure of SSL-25 in lipid bilayers, a series of 19 F-labeled SSL-25 analogs were synthesized. Circular dichroism (CD) analysis showed that SSL-25 and all of its analogs formed α-helices in the presence of lipid vesicles, thus allowing a detailed analysis via oriented CD and solid-state NMR. The results suggest that SSL-25 resides on the membrane surface with a slight helix tilt angle. A detailed 19 F NMR analysis revealed that SSL-25 does not form a continuous helix. The α-helical structure of the N-terminal part of the peptide was preserved in membranes of different lipid compositions and at various peptide-to-lipid molar ratios, but the C-terminus was disordered and did not fold into a well-defined α-helical conformation. Furthermore, the NMR results showed that SSL-25 resides on the membrane surface and does not re-orient into the membrane in response to changes in either peptide concentration or membrane composition. SSL-25 does not aggregate and remains fully mobile within the membrane bilayer, as shown by 19 F NMR. SSL-25 has a high binding affinity toward bilayers mimicking bacterial lipid compositions, but does not bind to mammalian model membranes containing cholesterol. These observations may explain the selectivity of this peptide for bacterial membranes, and they are also in line with basic biophysical considerations on spontaneous lipid curvature and the general effect of cholesterol on peptide/lipid interactions. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. High Energy Density Electrolytic Capacitor

    Science.gov (United States)

    Evans, David A.

    1996-01-01

    A new type of electrolytic capacitor which combines an electrolytic capacitor anode with an electrochemical capacitor cathode was developed. The resulting capacitor has a four time higher energy density than standard electrolytic capacitors, with comparable electric performance. The prototype, a 480 microFarad, 200 V device, has an energy density exceeding 4 J/cc. Now a 680 microFarad 50 V, MIL-style all tantalum device has been constructed and is undergoing qualification testing. Pending a favorable outcome, work will begin on other ratings. The potential for commercially significant development exists in applying this technology to aluminum-based electrolytic capacitors. It is possible to at least double the energy density of aluminum electrolytics, while using existing manufacturing methods, and without adding material expense. Data presented include electrical characteristics and performance measurements of the 200 V and 50 V hybrid capacitors and results from ongoing qualification testing of the MIL-style tantalum capacitors.

  14. A case of localized adrenergic urticaria mimicking an allergic reaction to a sweat chloride test.

    Science.gov (United States)

    Klebanova, Y; LeGrys, V; Cooper, D; Levy, D; Santora, D; Schwindt, C

    2009-09-01

    Adrenergic urticaria (AU) is a rare type of physical urticaria triggered by stress. It is frequently confused with IgE-mediated urticaria or other physical urticarias. This report describes a case of localized adrenergic urticaria triggered by a sweat chloride test in an adolescent male with multiple atopic disorders. A pruritic papular rash at the site of a sweat chloride test prompted an evaluation for allergic and physical urticarias using multiple skin test methods. A positive intradermal skin test to noradrenaline, which reproduced the rash observed during the sweat test, lead to the diagnosis of adrenergic urticaria. This is the first case report describing an immediate adrenergic urticarial reaction to sweat chloride testing in a patient with other atopic disorders. Copyright 2009 Wiley-Liss, Inc.

  15. Abnormal Axon Reflex-Mediated Sweating Correlates with High State of Anxiety in Atopic Dermatitis

    Directory of Open Access Journals (Sweden)

    Akiko Kijima

    2012-01-01

    Conclusions: Although the number of study subjects was little, abnormal AXR sweating in patients with AD was observed. Correlative analysis suggests possible involvement of continuous anxiety and the immune system in such abnormal sudomotor function.

  16. Sweat Rate Prediction Equations for Outdoor Exercise with Transient Solar Radiation

    Science.gov (United States)

    2012-01-01

    clothing, aerobic fitness, and progressive dehydration . J Therm Biol 22: 331–342, 1997. 25. Matthew WT, Santee WR, Berglund LG. Solar Load Inputs for...code) Sweat rate prediction equations for outdoor exercise with transient solar radiation Richard R. Gonzalez,1 Samuel N. Cheuvront,2 Brett R. Ely,2...Moran DS, Hadid A, Endrusick TL, Sawka MN. Sweat rate prediction equations for outdoor exercise with transient solar radiation. J Appl Phys- iol 112

  17. Hydration profile and sweat loss perception of male and female division II basketball players during practice.

    Science.gov (United States)

    Thigpen, Lauren K; Green, James M; OʼNeal, Eric K

    2014-12-01

    Hydration affects multiple aspects of basketball performance, but few investigations have examined the hydration profiles of collegiate basketball players. We examined multiday prepractice hydration status of 11 male and 11 female NCAA (National Collegiate Athletic Association) Division II basketball players' sweat losses, fluid intake, and how accurately players estimated their sweat losses. Urine-specific gravity (USG) was spontaneously assessed before 2 practices. Sweat losses and fluid intakes were measured during a conditioning practice (CP) and sport-specific practice (SP). After practices, players filled 1,030 ml practice bottles to estimate their sweat losses. Urine-specific gravity between practices exhibited a moderate correlation (r = 0.54; p = 0.012) and were consistently high (17% of samples = USG >1.030) with no difference in mean USG between men (1.026 ± 0.004) and women (1.022 ± 0.008). Athletes' estimations of their sweat loss volumes between CP and the longer SP were strongly correlated (r = 0.88; p < 0.001). Estimation error was high (absolute error for both practices = 71 ± 52%) and error direction varied greatly within men. Women consistently underestimated sweat losses by 63 ± 28% and 65 ± 20% during CP and SP. Sweat losses during SP equaled 2,471 ± 495 ml and 1,910 ± 441 ml for men and women, respectively, but high practice fluid intake limited body mass losses to 1.1 ± 0.6% by the end of practice. It is plausible that hypohydration is related to poor conceptualization of sweat losses. Simulating the methodology of this study could help identify chronically hypohydrated athletes and be used to educate on between-practice fluid needs.

  18. A COMPARATIVE HISTOLOGICAL STUDY ON THE SWEAT GLAND OF CATTLE (B. INDICUS AND YAK (P. POEPHAGUS

    Directory of Open Access Journals (Sweden)

    Partha Das

    2014-12-01

    Full Text Available Yak and cattle are the species of different habitats, but are of the same genus Bos. In order to adapt to different habitats some changes may occur in cellular organizations, sweat gland morphology being one of the part of this cellular organization. The skin samples were collected from six adult nondescript male cattle and yak from five different anatomical regions viz., neck, dewlap, abdomen, back and prepuce. Sweat glands appeared tubular consisting of a secretary coil which was embedded in the dermis in cattle. In yak, the glands were saccular in the neck and dewlap regions and tubular in other regions. The sweat gland number (1729±3.44 in cattle was almost three times higher (P<0.01 than yak (615.82±3.44.Highest number of sweat gland population was found in back (1563.24±5.44 and lowest in abdomen (900.26±5.44 in both the species. Descending order of sweat gland number was detected in dewlap, neck and prepuce respectively in both the species. In cattle the sweat gland diameter was significantly (32.78±0.38 µm higher as compared to yak (27.68±0.38 ìm. The sweat gland number and nuclear diameter in cattle was more than yak. Acidophilic secretory granules of the glands were numerous in the supra-nuclear cytoplasm in case of cattle. These results suggest the hyper activity of sweat gland in controlling the thermo dynamics in cattle as compared to yak.

  19. Does Replacing Sodium Excreted in Sweat Attenuate the Health Benefits of Physical Activity?

    Science.gov (United States)

    Turner, Martin J; Avolio, Alberto P

    2016-08-01

    International guidelines suggest limiting sodium intake to 86-100 mmol/day, but average intake exceeds 150 mmol/day. Participants in physical activities are, however, advised to increase sodium intake before, during and after exercise to ensure euhydration, replace sodium lost in sweat, speed rehydration and maintain performance. A similar range of health benefits is attributable to exercise and to reduction in sodium intake, including reductions in blood pressure (BP) and the increase of BP with age, reduced risk of stroke and other cardiovascular diseases, and reduced risk of osteoporosis and dementia. Sweat typically contains 40-60 mmol/L of sodium, leading to approximately 20-90 mmol of sodium lost in one exercise session with sweat rates of 0.5-1.5 L/h. Reductions in sodium intake of 20-90 mmol/day have been associated with substantial health benefits. Homeostatic systems reduce sweat sodium as low as 3-10 mmol/L to prevent excessive sodium loss. "Salty sweaters" may be individuals with high sodium intake who perpetuate their "salty sweat" condition by continual replacement of sodium excreted in sweat. Studies of prolonged high intensity exercise in hot environments suggest that sodium supplementation is not necessary to prevent hyponatremia during exercise lasting up to 6 hr. We examine the novel hypothesis that sodium excreted in sweat during physical activity offsets a significant fraction of excess dietary sodium, and hence may contribute part of the health benefits of exercise. Replacing sodium lost in sweat during exercise may improve physical performance, but may attenuate the long-term health benefits of exercise.

  20. Plasma electrolytic oxidation of titanium in a phosphate/silicate electrolyte and tribological performance of the coatings

    Energy Technology Data Exchange (ETDEWEB)

    Aliasghari, S.; Skeldon, P., E-mail: p.skeldon@manchester.ac.uk; Thompson, G.E.

    2014-10-15

    Highlights: • Plasma electrolytic oxidation performed of titanium in silicate/phosphate electrolyte. • Range of duty cycle, current density, positive-to-negative current ratio studied. • Coatings contain anatase, rutile, Ti{sub 3}O{sub 5}, and amorphous silica. • Ptfe incorporated into coatings by addition of ptfe emulsion to the electrolyte. • Fiction reduced but wear life relatively short due to porosity of coatings. - Abstract: Plasma electrolytic oxidation of titanium has been investigated using a phosphate/silicate electrolyte with a square waveform and a frequency of 50 Hz. A range of constant rms current densities, duty cycles and negative-to-positive current ratios was employed. The resultant coatings were examined by analytical scanning and transmission electron microscopies and X-ray diffraction. The coatings, which were limited in thickness to ∼40 to 50 μm, contained anatase, rutile, Ti{sub 2}O{sub 5} and silicon-rich, amorphous material. The tribological behaviour was investigated using a ball-on-disc test, revealing a coefficient of friction against steel of ∼0.8, which reduced to ∼0.4 by incorporation of ptfe particles from the electrolyte. However, due to the composition and morphology of the coatings, their wear life was relatively short.

  1. Association between pulse wave velocity and hot flashes/sweats in middle-aged women.

    Science.gov (United States)

    Yang, Ruwei; Zhou, Yang; Li, Changbin; Tao, Minfang

    2017-10-23

    As women age and go through menopause, they suffer a higher incidence of cardiovascular morbidity and mortality. Previous studies have shown that a relationship exists between hot flashes/sweats and an increased risk of cardiovascular disease. However, the association between hot flashes/sweats and arterial stiffness is unclear. We aim to explore the relationship between hot flashes/sweats and arterial stiffness using the modified Kupperman index (KMI) questionnaire and measure the brachial-ankle pulse wave velocity (baPWV). The prevalence of hot flashes in our research was reported to be 41.77%. There was a statistically significant difference between the mean baPWV among groups that experienced different severities of hot flashes/sweats according to one-way ANOVA test (p hot flashes/sweats based on linear regression after adjusting for established cardiovascular confounders (95% CI: (5.86, 43.23), p = 0.01). To the best of our knowledge, this study is the first investigation to propose that baPWV may serve both as an objective index for evaluating the severity of hot flashes/sweats and as a predictor of arterial stiffness beyond Cardiac Vascular Disease (CVD) risk factors in middle-aged women.

  2. A soft, wearable microfluidic device for the capture, storage, and colorimetric sensing of sweat.

    Science.gov (United States)

    Koh, Ahyeon; Kang, Daeshik; Xue, Yeguang; Lee, Seungmin; Pielak, Rafal M; Kim, Jeonghyun; Hwang, Taehwan; Min, Seunghwan; Banks, Anthony; Bastien, Philippe; Manco, Megan C; Wang, Liang; Ammann, Kaitlyn R; Jang, Kyung-In; Won, Phillip; Han, Seungyong; Ghaffari, Roozbeh; Paik, Ungyu; Slepian, Marvin J; Balooch, Guive; Huang, Yonggang; Rogers, John A

    2016-11-23

    Capabilities in health monitoring enabled by capture and quantitative chemical analysis of sweat could complement, or potentially obviate the need for, approaches based on sporadic assessment of blood samples. Established sweat monitoring technologies use simple fabric swatches and are limited to basic analysis in controlled laboratory or hospital settings. We present a collection of materials and device designs for soft, flexible, and stretchable microfluidic systems, including embodiments that integrate wireless communication electronics, which can intimately and robustly bond to the surface of the skin without chemical and mechanical irritation. This integration defines access points for a small set of sweat glands such that perspiration spontaneously initiates routing of sweat through a microfluidic network and set of reservoirs. Embedded chemical analyses respond in colorimetric fashion to markers such as chloride and hydronium ions, glucose, and lactate. Wireless interfaces to digital image capture hardware serve as a means for quantitation. Human studies demonstrated the functionality of this microfluidic device during fitness cycling in a controlled environment and during long-distance bicycle racing in arid, outdoor conditions. The results include quantitative values for sweat rate, total sweat loss, pH, and concentration of chloride and lactate. Copyright © 2016, American Association for the Advancement of Science.

  3. Estimation of sweat rates during cycling exercise by means of the closed chamber condenser technology.

    Science.gov (United States)

    Clarys, P; Clijsen, R; Barel, A O; Schouteden, R; van Olst, B; Aerenhouts, D

    2017-02-01

    Knowledge of local sweating patterns is of importance in occupational and exercise physiology settings. The recently developed closed chamber condenser technology (Biox Aquaflux ® ) allows the measurement of evaporative skin water loss with a greater measurement capacity (up to 1325 g/h/m 2 ) compared to traditional evaporimeters. The aim of this study was to evaluate the applicability of the Biox Aquaflux ® to estimate sweat production during exercise. Fourteen healthy subjects performed a 20-min cycle ergometer trial at respectively 55% heart rate (HR reserve and 75% HR reserve . Sweat production was estimated by measuring body weight before and after exercise, by calculating the amount of sweat collected in a patch, and by measuring the water flux (in g/h/m 2 ) with the Biox Aquaflux ® instrument. The Biox Aquaflux ® instrument allowed the follow up of sweat kinetics at both intensities. Correlations between the measurement methods were all significant for the 75% HR reserve trial (with r ranging from 0.68 to 0.76) whilst for the 55% HR reserve a significant relation was detected between the patch method and the Biox Aquaflux ® only (with r ranging from 0.41 to 0.79). The Biox Aquaflux ® instrument is a practical and direct method for the estimation of local sweat rates under field conditions. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Noninvasive monitoring of plasma L-dopa concentrations using sweat samples in Parkinson's disease.

    Science.gov (United States)

    Tsunoda, Makoto; Hirayama, Masaaki; Tsuda, Takao; Ohno, Kinji

    2015-03-10

    L-dopa (l-3,4-dihydroxyphenylalanine) is commonly used for treating Parkinson's disease (PD). However, regardless of its prominent effect, therapeutic range of L-dopa narrows down with disease progression, which leads to development of motor complications including wearing off and dyskinesias. In addition, intestinal absorption of L-dopa is inversely correlated with the amount of oral protein intake, and shows intra- and inter-day variability. Hence, frequent monitoring of plasma L-dopa concentrations is beneficial, but frequent venipuncture imposes physical and psychological burdens on patients with PD. We investigated the usefulness of sweat samples instead of plasma samples for monitoring L-dopa concentrations. With a monolithic silica disk-packed spin column and the high-performance liquid chromatography-electrochemical detection system, L-dopa in sweat samples was successfully quantified and analyzed in 23 PD patients. We found that the Pearson's correlation coefficient of the plasma and sweat l-dopa concentrations was 0.678. Although the disease durations and severities were not correlated with the deviation of the actual sweat L-dopa concentrations from the fitted line, acquisition of the sweat samples under a stable condition was technically difficult in severely affected patients. The deviations may also be partly accounted for by skin permeability of L-dopa. Measuring L-dopa concentrations in sweat is suitable to get further insights into the L-dopa metabolism. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Wearable/disposable sweat-based glucose monitoring device with multistage transdermal drug delivery module

    Science.gov (United States)

    Lee, Hyunjae; Song, Changyeong; Hong, Yong Seok; Kim, Min Sung; Cho, Hye Rim; Kang, Taegyu; Shin, Kwangsoo; Choi, Seung Hong; Hyeon, Taeghwan; Kim, Dae-Hyeong

    2017-01-01

    Electrochemical analysis of sweat using soft bioelectronics on human skin provides a new route for noninvasive glucose monitoring without painful blood collection. However, sweat-based glucose sensing still faces many challenges, such as difficulty in sweat collection, activity variation of glucose oxidase due to lactic acid secretion and ambient temperature changes, and delamination of the enzyme when exposed to mechanical friction and skin deformation. Precise point-of-care therapy in response to the measured glucose levels is still very challenging. We present a wearable/disposable sweat-based glucose monitoring device integrated with a feedback transdermal drug delivery module. Careful multilayer patch design and miniaturization of sensors increase the efficiency of the sweat collection and sensing process. Multimodal glucose sensing, as well as its real-time correction based on pH, temperature, and humidity measurements, maximizes the accuracy of the sensing. The minimal layout design of the same sensors also enables a strip-type disposable device. Drugs for the feedback transdermal therapy are loaded on two different temperature-responsive phase change nanoparticles. These nanoparticles are embedded in hyaluronic acid hydrogel microneedles, which are additionally coated with phase change materials. This enables multistage, spatially patterned, and precisely controlled drug release in response to the patient’s glucose level. The system provides a novel closed-loop solution for the noninvasive sweat-based management of diabetes mellitus. PMID:28345030

  6. Sweat lipid mediator profiling: a noninvasive approach for cutaneous research[S

    Science.gov (United States)

    Hassoun, Lauren A.; Foolad, Negar; Pedersen, Theresa L.; Sivamani, Raja K.; Newman, John W.

    2017-01-01

    Recent advances in analytical and sweat collection techniques provide new opportunities to identify noninvasive biomarkers for the study of skin inflammation and repair. This study aims to characterize the lipid mediator profile including oxygenated lipids, endocannabinoids, and ceramides/sphingoid bases in sweat and identify differences in these profiles between sweat collected from nonlesional sites on the unflared volar forearm of subjects with and without atopic dermatitis (AD). Adapting routine procedures developed for plasma analysis, over 100 lipid mediators were profiled using LC-MS/MS and 58 lipid mediators were detected in sweat. Lipid mediator concentrations were not affected by sampling or storage conditions. Increases in concentrations of C30–C40 [NS] and [NdS] ceramides, and C18:1 sphingosine, were observed in the sweat of study participants with AD despite no differences being observed in transepidermal water loss between study groups, and this effect was strongest in men (P Sweat mediator profiling may therefore provide a noninvasive diagnostic for AD prior to the presentation of clinical signs. PMID:27875258

  7. Lack of harmonization in sweat testing for cystic fibrosis - a national survey.

    Science.gov (United States)

    Christiansen, Anne Lindegaard; Nybo, Mads

    2014-11-01

    Sweat testing is used in the diagnosis of cystic fibrosis. Interpretation of the sweat test depends, however, on the method performed since conductivity, osmolality and chloride concentration all can be measured as part of a sweat test. The aim of this study was to investigate how performance of the test is organized in Denmark. Departments conducting the sweat test were contacted and interviewed following a premade questionnaire. They were asked about methods performed, applied NPU (Nomenclature for Properties and Units) code, reference interval, recommended interpretation and referred literature. 14 departments performed the sweat test. One department measured chloride and sodium concentration, while 13 departments measured conductivity. One department used a non-existing NPU code, two departments applied NPU codes inconsistent with the method performed, four departments applied no NPU code and seven applied a correct NPU code. Ten of the departments measuring conductivity applied reference intervals. Nine departments measuring conductivity had recommendations of a normal area, a grey zone and a pathological value, while four departments only applied a normal and grey zone or a pathological value. Cut-off values for normal, grey and pathological areas were like the reference intervals inconsistent. There is inconsistent use of NPU codes, reference intervals and interpretation of sweat conductivity used in the process of diagnosing cystic fibrosis. Because diagnosing cystic fibrosis is a combined effort between local pediatric departments, biochemical and genetic departments and cystic fibrosis centers, a national harmonization is necessary to assure correct clinical use.

  8. Stretchable, wireless sensors and functional substrates for epidermal characterization of sweat.

    Science.gov (United States)

    Huang, Xian; Liu, Yuhao; Chen, Kaile; Shin, Woo-Jung; Lu, Ching-Jui; Kong, Gil-Woo; Patnaik, Dwipayan; Lee, Sang-Heon; Cortes, Jonathan Fajardo; Rogers, John A

    2014-08-13

    This paper introduces materials and architectures for ultrathin, stretchable wireless sensors that mount on functional elastomeric substrates for epidermal analysis of biofluids. Measurement of the volume and chemical properties of sweat via dielectric detection and colorimetry demonstrates some capabilities. Here, inductively coupled sensors consisting of LC resonators with capacitive electrodes show systematic responses to sweat collected in microporous substrates. Interrogation occurs through external coils placed in physical proximity to the devices. The substrates allow spontaneous sweat collection through capillary forces, without the need for complex microfluidic handling systems. Furthermore, colorimetric measurement modes are possible in the same system by introducing indicator compounds into the depths of the substrates, for sensing specific components (OH(-) , H(+) , Cu(+) , and Fe(2+) ) in the sweat. The complete devices offer Young's moduli that are similar to skin, thus allowing highly effective and reliable skin integration without external fixtures. Experimental results demonstrate volumetric measurement of sweat with an accuracy of 0.06 μL/mm(2) with good stability and low drift. Colorimetric responses to pH and concentrations of various ions provide capabilities relevant to analysis of sweat. Similar materials and device designs can be used in monitoring other body fluids. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Higher sweat chloride levels in patients with asthma: a case-control study.

    Science.gov (United States)

    Awasthi, Shally; Dixit, Pratibha; Maurya, Nutan

    2015-02-01

    To screen asthmatic patients by sweat chloride test to identify proportion with Cystic Fibrosis (CF); (Sweat chloride level >60 mmol/L). Also, to compare sweat chloride levels between cases of bronchial asthma and age and sex matched healthy children aged 5 mo-15 y. The present case-control study was conducted in a tertiary care hospital in India. Cases of bronchial asthma, diagnosed by GINA guideline 2008, and age matched healthy controls were included. Case to control ratio was 2:1. Sweat Chloride test was done by Pilocarpine Iontophoresis method. From April 2010 through May 2012, 216 asthmatics and 112 controls were recruited. Among asthmatics, there was no case of Cystic Fibrosis. Mean sweat chloride levels in asthmatics was 22.39 ± 8.45 mmol/L (inter-quartile range - 15-28 mmol/L) and in controls 19.55 ± 7.04 mmol/L (inter-quartile range - 15-23.5 mmol/L) (p value = 0.048). No Cystic Fibrosis case was identified among asthmatics. Mean sweat chloride levels were higher in asthmatics as compared to controls.

  10. Higher sweating rate and skin blood flow during the luteal phase of the menstrual cycle.

    Science.gov (United States)

    Lee, Haneul; Petrofsky, Jerrold; Shah, Nirali; Awali, Abdulaziz; Shah, Karan; Alotaibi, Mohammed; Yim, JongEun

    2014-10-01

    Evaporation by sweating is the most effective way to remove heat from the body. Sweat rates increase under both local and whole-body heat stress. Men and women differ in how they respond to heat, because sexual steroids alter resting body core temperature and the threshold for sweating and skin blood flow (SBF) during heating. The purpose of the present study was to compare local sweat rates and cutaneous vasodilatation during heat exposure in women with a regular menstrual cycle. The cutaneous vasodilatation was judged by measuring the SBF. Eight female and nine male subjects participated in this study, and their age range was 24-29 years. Female subjects were tested twice throughout one full menstrual cycle: once during the middle follicular phases and once during the luteal phase. Subjects remained in a temperature-regulated room at 41°C and 21% of relative humidity for 40 minutes. Sweat rate was recorded from the forehead, forearm, and thigh, and skin temperature and SBF were measured on the thigh and forehead. We found that the sweating rate and SBF were greater in the luteal phase compared to follicular phase (p0.05). We propose the enhanced sympathetic activity in the luteal phase with a regular menstrual cycle.

  11. Control of sweating in man after work-induced thermal load and symmetrically applied cooling.

    Science.gov (United States)

    Heising, M; Werner, J

    1987-01-01

    To examine the compensatory effects of work-induced thermal load and symmetrically applied local cooling on local sweat rates, two kinds of experiment were carried out on eight male subjects in a climatic chamber: 1) Experiments at 36 degrees C ambient temperature with a work load of about 25 W by the right leg. 2) Experiments at 36 degrees C ambient temperature with a work load of about 25 W by the right leg as in 1., but with additional compensatory cooling of the left leg controlled throughout by heat balance calculations at 75-85 W, equal to the heat produced in the working leg, the necessary air temperature being dependent on local sweat rate. Work load without cooling brought about a significant increase in core temperatures, metabolism, heart rate and local sweat rates. With unchanged local skin temperatures local sweat rate increase was higher in the working leg. Therefore the existence of muscle thermoreceptors should be assumed, the afferent information from which is processed and weighted in a different way to that provided by skin receptors. Work load combined with additional cooling reduced local and mean skin temperatures and heart rate, but had no significant influence on core temperature or metabolism. However, local sweat rate was generally lower in both thighs, with a major reduction in the cooled leg confirming control of local sweat rate by local temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Maximum rate of sweat ions reabsorption during exercise with regional differences, sex, and exercise training.

    Science.gov (United States)

    Amano, Tatsuro; Hirose, Megumi; Konishi, Kana; Gerrett, Nicola; Ueda, Hiroyuki; Kondo, Narihiko; Inoue, Yoshimitsu

    2017-07-01

    It is recently reported that determining sweat rate (SR) threshold for increasing galvanic skin conductance (GSC) would represent a maximum rate of sweat ion reabsorption in sweat glands. We evaluate the maximum rate of sweat ion reabsorption over skin regions, sex, and long-term exercise training by using the threshold analysis in the present study. Ten males (2 untrained, 4 sprinters, and 4 distance runners) and 12 females (5 untrained, 4 sprinters, and 3 distance runners) conducted graded cycling exercise for 45 min at low, middle, and high exercise intensities (heart rate 100-110, 120-130, and 140-150 beats/min, respectively) for 10, 15, and 20 min, respectively, at 30 °C and 50% relative humidity. Comparisons were made between males and females and among untrained individuals, distance runners, and sprinters on the back and forearm. SR threshold for increasing GSC on back was significantly higher than that of forearm (P sprinters showed higher SR threshold for increasing GSC than that of untrained subjects on back (P sprinters, respectively). These results suggest that the maximum sweat ion reabsorption rate on the back is higher than that of forearm without sex differences. Furthermore, exercise training in distance runners and sprinters improves the maximum sweat ion reabsorption rate on the back.

  13. A solid-polymer-electrolyte direct methanol fuel cell (DMFC) with Pt ...

    Indian Academy of Sciences (India)

    polymer-electrolyte direct methanol fuel cell (DMFC) with Pt-Ru nanoparticles supported onto poly(3,4-ethylenedioxythiophene) and polystyrene sulphonic acid polymer composite as anode. K K Tintula S Pitchumani P Sridhar A K Shukla.

  14. COMPOSITE

    African Journals Online (AJOL)

    An effective medium theory of ferroelectric ceramic-polymer composite materials which treats both components symmetrically has been investigated to demonstrate the role played by the microgeometry of inclusions on dielectric, mechanical and piezoelectric properties of 0-3 composites. The limits of the various theoretical ...

  15. New functions and applications of walter, the sweating fabric manikin.

    Science.gov (United States)

    Fan, Jintu; Qian, Xiaoming

    2004-09-01

    In this paper, latest developments on Walter, a sweating fabric manikin, are reported. These include the improved simulation of "walking motion", the design and construction of an automated water supply, and real-time measurement of evaporative water loss and regulation of "skin" temperature through the regulation of the pumps inside the manikin body. Testing of commercial garment ensembles showed that the measurement of thermal insulation and moisture-vapour resistance of clothing is very reproducible with the coefficient of variation being generally less than 5%. It was also shown that, in addition to the thermal insulation and moisture-vapour resistance, the percentage of moisture accumulation within clothing is a very useful parameter of clothing comfort. The improved manikin has been used to investigate the effects of walking motion on thermal insulation and evaporative resistance of clothing. The trend of the effects of walking speed up to 1.13 m s(-1) for the nude manikin and when it was wearing garments of different sizes are reported.

  16. Lithium ion conducting ionic electrolytes

    Science.gov (United States)

    Angell, C. Austen; Xu, Kang; Liu, Changle

    1996-01-01

    A liquid, predominantly lithium-conducting, ionic electrolyte is described which has exceptionally high conductivity at temperatures of 100.degree. C. or lower, including room temperature. It comprises molten lithium salts or salt mixtures in which a small amount of an anionic polymer lithium salt is dissolved to stabilize the liquid against recrystallization. Further, a liquid ionic electrolyte which has been rubberized by addition of an extra proportion of anionic polymer, and which has good chemical and electrochemical stability, is described. This presents an attractive alternative to conventional salt-in-polymer electrolytes which are not cationic conductors.

  17. Lithium ion conducting ionic electrolytes

    Science.gov (United States)

    Angell, C.A.; Xu, K.; Liu, C.

    1996-01-16

    A liquid, predominantly lithium-conducting, ionic electrolyte is described which has exceptionally high conductivity at temperatures of 100 C or lower, including room temperature. It comprises molten lithium salts or salt mixtures in which a small amount of an anionic polymer lithium salt is dissolved to stabilize the liquid against recrystallization. Further, a liquid ionic electrolyte which has been rubberized by addition of an extra proportion of anionic polymer, and which has good chemical and electrochemical stability, is described. This presents an attractive alternative to conventional salt-in-polymer electrolytes which are not cationic conductors. 4 figs.

  18. Variability of sweat chloride concentration in subjects with cystic fibrosis and G551D mutations.

    Science.gov (United States)

    Vermeulen, F; Le Camus, C; Davies, J C; Bilton, D; Milenković, D; De Boeck, K

    2017-01-01

    Sweat chloride concentration, a biomarker of CFTR function, is an appropriate outcome parameter in clinical trials aimed at correcting the basic CF defect. Although there is consensus on a cut-off value to diagnose CF, we have only limited information on the within subject variability of sweat chloride over time. Such information would be useful for sample size calculations in clinical trials. Therefore, we retrospectively analyzed repeated sweat chloride values obtained in patients with G551D mutation(s) assigned to placebo in an ivacaftor interventional trial. In subjects with G551D at least 12years of age, a pilocarpine sweat test using Macroduct collector was taken on both arms at 8 time points over 48weeks. We explored 1062 pilocarpine sweat test values obtained in 78 placebo patients of the VX08-770-102 trial. Mean overall sweat chloride value (all patients, all tests, n=1062) was 100.8mmol/L (SD 12.7mmol/L). Using a multilevel mixed model, the between-subject standard deviation (SD) for sweat chloride was 8.9mmol/L (95% CI 7.4-10.6) and within-subject SD was 8.1mmol/L (95% CI 7.5-8.7). Limits of repeatability for repeat measurements were -19.7 to +21.6mmol/L using values from one arm, and -13.3 to 11.8mmol/L using mean of values obtained at 4 test occasions. Sample size calculations showed that the minimal treatment effect on sweat chloride concentration that can be demonstrated for a group of 5 patients is around 15mmol/L, using a cross-over design and combinations of 4 tests for each phase of the trial. Although the sweat test is considered a robust measure, sweat chloride measurements in patients with CF and a G551D mutation had an inherent biological variability that is higher than commonly considered. Further analyses of placebo group data are crucial to learn more about the natural variability of this outcome parameter. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  19. Normal sweat secretion despite impaired growth hormone-insulin-like growth factor-I axis in obese subjects

    DEFF Research Database (Denmark)

    Rasmussen, Michael Højby; Juul, Anders; Main, Katharina M

    2011-01-01

    Adults with GH deficiency are known to exhibit reduced sweating. Whether sweating capacity is impacted in obese subjects with impaired GH secretion have not previously been investigated. The main objective was to investigate sweat secretion rate and the GH-IGF-I axis in obese subjects before......, and impaired insulin sensitivity, which all were normalised after diet-induced weight loss of 30 ± 5 kg. Sweat secretion rates were similar comparing obese and nonobese subjects (78 ± 10 versus 82 ± 9 mg/30 minutes) and sweat secretion did not change after a diet-induced weight loss in obese subjects. We...... conclude that although obese subjects have markedly reduced GH release and impaired IGF-I levels, sweat secretion rate is found to be normal....

  20. Association of sweat chloride concentration at time of diagnosis and CFTR genotype with mortality and cystic fibrosis phenotype.

    Science.gov (United States)

    McKone, Edward F; Velentgas, Priscilla; Swenson, Anna J; Goss, Christopher H

    2015-09-01

    The extent to which sweat chloride concentration predicts survival and clinical phenotype independently of CFTR genotype in cystic fibrosis is not well understood. We analyzed the US Cystic Fibrosis Foundation Patient Registry data using Cox regression to examine the relationship between sweat chloride concentration (sweat chloride, CFTR genotype, and measures of lung function and growth. When included in the same model, CFTR genotype, but not sweat chloride, was independently associated with survival and with lung function, height, and BMI. Among patients with unclassified CFTR genotype, sweat chloride was an independent predictor of survival (Sweat chloride concentration may be a useful predictor of mortality and clinical phenotype when CFTR genotype functional class is unclassified. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.