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Sample records for sweat electrolyte concentrations

  1. 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

  2. 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...

  3. 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 ...

  4. 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.

  5. 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 ...

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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 ...

  11. 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...

  12. 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...

  13. 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 ...

  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. 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.

  16. 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.

  17. 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.

  18. 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 ...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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 ...

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. Colloidal Electrolytes and the Critical Micelle Concentration

    Science.gov (United States)

    Knowlton, L. G.

    1970-01-01

    Describes methods for determining the Critical Micelle Concentration of Colloidal Electrolytes; methods described are: (1) methods based on Colligative Properties, (2) methods based on the Electrical Conductivity of Colloidal Electrolytic Solutions, (3) Dye Method, (4) Dye Solubilization Method, and (5) Surface Tension Method. (BR)

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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).

  19. 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.

  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.

  1. 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.

  2. Electrochemical behaviour of brass in chloride solution concentrations found in eccrine fingerprint sweat

    Energy Technology Data Exchange (ETDEWEB)

    Bond, John W., E-mail: jwb13@le.ac.uk [Department of Chemistry, George Porter Building, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Lieu, Elaine [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

    2014-09-15

    Highlights: • Corrosion of brass in NaCl concentrations found in eccrine sweat was investigated. • Concentrations < 0.2 M produce a layer of mainly zinc oxide after 24 h. • A concentration of 0.2 M enables active corrosion of brass at room temperature. • 0.2 M NaCl gives both zinc and copper dissolution. • 24-h immersion of brass in 0.2 M NaCl gives an oxide film thickness of 1.3 nm. - Abstract: In this work, the corrosion properties of α phase brass immersed in concentrations of aqueous NaCl solutions that are typically found in eccrine fingerprint sweat and range between 0.01 M and 0.2 M have been analysed. Analysis methods employed were electrochemical techniques, X-ray photoelectron spectroscopy and optical profiling. For NaCl concentrations <0.2 M, active corrosion did not occur although, after a period of 24 h, a passivating layer of mainly zinc oxide formed. At a concentration of 0.2 M active corrosion did occur, with measured corrosion potentials consistent with both brass and copper dissolution. A 1 h contact time at this concentration (0.2 M) resulted in the formation of a zinc oxide passivating layer with the surface ratio of zinc oxide to copper oxide increasing with time. Film thickness was calculated to be of the order of 1.3 nm after 24 h contact. Formation of oxide layers on brass by fingerprint sweat as observed here may well have implications for the successful investigation of crime by the visualisation of corrosion fingerprint ridge patterns or the reduction of hospital environmental contamination by hand contact with brass objects such as door handles or taps.

  3. Measurement of sodium concentration in sweat samples: comparison of 5 analytical techniques.

    Science.gov (United States)

    Goulet, Eric D B; Asselin, Audrey; Gosselin, Jonathan; Baker, Lindsay B

    2017-08-01

    Sweat sodium concentration (SSC) can be determined using different analytical techniques (ATs), which may have implications for athletes and scientists. This study compared the SSC measured with 5 ATs: ion chromatography (IChr), flame photometry (FP), direct (DISE) and indirect (IISE) ion-selective electrode, and ion conductivity (IC). Seventy sweat samples collected from 14 athletes were analyzed with 5 instruments: the 883 Basic IC Plus (IChr, reference instrument), AAnalyst 200 (FP), Cobas 6000 (IISE), Sweat-Chek (IC), and B-722 Laqua Twin (DISE). Instruments showed excellent relative (intraclass correlation coefficient (ICC) ≥ 0.999) and absolute (coefficient of variation (CV) ≤ 2.6%) reliability. Relative validity was also excellent between ATs (ICC ≥ 0.961). In regards to the inter-AT absolute validity, compared with IChr, standard error of the estimates were similar among ATs (2.8-3.8 mmol/L), but CV was lowest with DISE (3.9%), intermediate with IISE (7.6%), and FP (6.9%) and highest with IC (12.3%). In conclusion, SSC varies depending on the AT used to analyze samples. Therefore, results obtained from different ATs are scarcely comparable and should not be used interchangeably. Nevertheless, taking into account the normal variability in SSC (∼±12%), the imprecision of the recommendations deriving from FP, IISE, IC, and DISE should have trivial health and physiological consequences under most exercise circumstances.

  4. Electrolytes concentration patterns in the three trimesters of pregnancy

    African Journals Online (AJOL)

    The physiologic adaptations of the pregnant woman involve the renal, cardiovascular and other systems of the body. This study aimed at evaluating electrolyte concentrations in the three trimesters of pregnancy. Blood samples were collected by aseptic techniques and the concentrations of electrolytes were determined ...

  5. Monitoring electrolyte concentrations in redox flow battery systems

    Energy Technology Data Exchange (ETDEWEB)

    Chang, On Kok; Sopchak, David Andrew; Pham, Ai Quoc; Kinoshita, Kimio

    2015-03-17

    Methods, systems and structures for monitoring, managing electrolyte concentrations in redox flow batteries are provided by introducing a first quantity of a liquid electrolyte into a first chamber of a test cell and introducing a second quantity of the liquid electrolyte into a second chamber of the test cell. The method further provides for measuring a voltage of the test cell, measuring an elapsed time from the test cell reaching a first voltage until the test cell reaches a second voltage; and determining a degree of imbalance of the liquid electrolyte based on the elapsed time.

  6. 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...

  7. 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...

  8. 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 ...

  9. 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

  10. Temperature and concentration dependences of the activity coefficients of electrolytes

    Science.gov (United States)

    Tikhonov, N. A.; Sidel'nikov, G. B.

    2017-10-01

    A model has been suggested that describes the interaction of hydrated ions in electrolytes and allows the calculation of the main physical effects. The model explains the character of the curves of the activity coefficients. Binary solutions of uni-univalent electrolytes at concentrations from zero to several moles per liter and at temperatures from zero to a few dozens of degrees were studied. The results of simulation were verified by comparing them with many literature data.

  11. 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.

  12. 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 ...

  13. 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.

  14. Scaling Analysis of the Screening Length in Concentrated Electrolytes

    Science.gov (United States)

    Lee, Alpha A.; Perez-Martinez, Carla S.; Smith, Alexander M.; Perkin, Susan

    2017-07-01

    The interaction between charged objects in an electrolyte solution is a fundamental question in soft matter physics. It is well known that the electrostatic contribution to the interaction energy decays exponentially with object separation. Recent measurements reveal that, contrary to the conventional wisdom given by the classic Poisson-Boltzmann theory, the decay length increases with the ion concentration for concentrated electrolytes and can be an order of magnitude larger than the ion diameter in ionic liquids. We derive a simple scaling theory that explains this anomalous dependence of the decay length on the ion concentration. Our theory successfully collapses the decay lengths of a wide class of salts onto a single curve. A novel prediction of our theory is that the decay length increases linearly with the Bjerrum length, which we experimentally verify by surface force measurements. Moreover, we quantitatively relate the measured decay length to classic measurements of the activity coefficient in concentrated electrolytes, thus showing that the measured decay length is indeed a bulk property of the concentrated electrolyte as well as contributing a mechanistic insight into empirical activity coefficients.

  15. 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.

  16. Common Student Misconceptions in Electrochemistry: Galvanic, Electrolytic, and Concentration Cells.

    Science.gov (United States)

    Sanger, Michael J.; Greenbowe, Thomas J.

    1997-01-01

    Investigates student (N=16) misconceptions concerning electrochemistry related to galvanic, electrolytic, and concentration cells. Findings indicate that most students demonstrating misconceptions were still able to calculate cell potentials correctly. Discusses common misconceptions and possible sources of these. Contains 33 references.…

  17. Loss of carbonic anhydrase XII function in individuals with elevated sweat chloride concentration and pulmonary airway disease.

    Science.gov (United States)

    Lee, Melissa; Vecchio-Pagán, Briana; Sharma, Neeraj; Waheed, Abdul; Li, Xiaopeng; Raraigh, Karen S; Robbins, Sarah; Han, Sangwoo T; Franca, Arianna L; Pellicore, Matthew J; Evans, Taylor A; Arcara, Kristin M; Nguyen, Hien; Luan, Shan; Belchis, Deborah; Hertecant, Jozef; Zabner, Joseph; Sly, William S; Cutting, Garry R

    2016-05-15

    Elevated sweat chloride levels, failure to thrive (FTT), and lung disease are characteristic features of cystic fibrosis (CF, OMIM #219700). Here we describe variants in CA12 encoding carbonic anhydrase XII in two pedigrees exhibiting CF-like phenotypes. Exome sequencing of a white American adult diagnosed with CF due to elevated sweat chloride, recurrent hyponatremia, infantile FTT and lung disease identified deleterious variants in each CA12 gene: c.908-1 G>A in a splice acceptor and a novel frameshift insertion c.859_860insACCT. In an unrelated consanguineous Omani family, two children with elevated sweat chloride, infantile FTT, and recurrent hyponatremia were homozygous for a novel missense variant (p.His121Gln). Deleterious CFTR variants were absent in both pedigrees. CA XII protein was localized apically in human bronchiolar epithelia and basolaterally in the reabsorptive duct of human sweat glands. Respiratory epithelial cell RNA from the adult proband revealed only aberrant CA12 transcripts and in vitro analysis showed greatly reduced CA XII protein. Studies of ion transport across respiratory epithelial cells in vivo and in culture revealed intact CFTR-mediated chloride transport in the adult proband. CA XII protein bearing either p.His121Gln or a previously identified p.Glu143Lys missense variant localized to the basolateral membranes of polarized Madin-Darby canine kidney (MDCK) cells, but enzyme activity was severely diminished when assayed at physiologic concentrations of extracellular chloride. Our findings indicate that loss of CA XII function should be considered in individuals without CFTR mutations who exhibit CF-like features in the sweat gland and lung. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. 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...

  19. 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.

  20. 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…

  1. Electrolytes supramolecular interactions and non-equilibrium phenomena in concentrated solutions

    CERN Document Server

    Aseyev, Georgii Georgievich

    2014-01-01

    Electrolyte solutions play a key role in traditional chemical industry processes as well as other sciences such as hydrometallurgy, geochemistry, and crystal chemistry. Knowledge of electrolyte solutions is also key in oil and gas exploration and production, as well as many other environmental engineering endeavors. Until recently, a gap existed between the electrolyte solution theory dedicated to diluted solutions, and the theory, practice, and technology involving concentrated solutions.Electrolytes: Supramolecular Interactions and Non-Equilibrium Phenomena in Concentrated Solutions addresse

  2. 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.

  3. 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.

  4. 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.

  5. Ion-dipole interactions in concentrated organic electrolytes.

    Science.gov (United States)

    Chagnes, Alexandre; Nicolis, Stamatios; Carré, Bernard; Willmann, Patrick; Lemordant, Daniel

    2003-06-16

    An algorithm is proposed for calculating the energy of ion-dipole interactions in concentrated organic electrolytes. The ion-dipole interactions increase with increasing salt concentration and must be taken into account when the activation energy for the conductivity is calculated. In this case, the contribution of ion-dipole interactions to the activation energy for this transport process is of the same order of magnitude as the contribution of ion-ion interactions. The ion-dipole interaction energy was calculated for a cell of eight ions, alternatingly anions and cations, placed on the vertices of an expanded cubic lattice whose parameter is related to the mean interionic distance (pseudolattice theory). The solvent dipoles were introduced randomly into the cell by assuming a randomness compacity of 0.58. The energy of the dipole assembly in the cell was minimized by using a Newton-Raphson numerical method. The dielectric field gradient around ions was taken into account by a distance parameter and a dielectric constant of epsilon = 3 at the surfaces of the ions. A fair agreement between experimental and calculated activation energy has been found for systems composed of gamma-butyrolactone (BL) as solvent and lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluorophosphate (LiPF6), lithium hexafluoroarsenate (LiAsF6), and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) as salts.

  6. Leaching from the stratum corneum does not explain the previously reported elevated potassium ion concentration in sweat.

    Science.gov (United States)

    Buono, Michael J; Stone, Michael; Cannon, Daniel T

    2016-03-01

    The purpose of this study was to determine if K+ is leached from the stratum corneum when sweat is present on the skin's surface. The results will help address whether sweat [K+] previously reported in the literature are artifactually elevated as a result of K+ leaching. Twelve (six female, six male) healthy volunteers participated in this study. After thorough skin cleansing and preparation with isopropyl alcohol and high-performance liquid chromatography-grade distilled water, three sites were chosen and a 50 μL drop of artificial sweat was pipetted directly onto the skin. The artificial sweat had a [K+] of 4 mEq·L-1, an osmolality of 120 mosm·L-1, and a pH of 6.0. Immediately following, a clear plastic cover slip (~6 cm2) with a shallow 0.8 cm2 convex impression in the center was applied over each drop, preventing evaporation. Each sample was allowed to sit on the forearm, under the plastic cover slip, for 10 min. The mean (±SD) [K+] in 'artificial' sweat not exposed to the skin was measured to be 4.2±0.4 mEq·L-1. After 10 min of exposure to the stratum corneum of the forearm, the artificial sweat had a mean (±SD) [K+] of 3.9±0.3 mEq·L-1. There was no significant difference (p>0.05) in the [K+] between the control artificial sweat and the samples collected after 10 min of exposure to forearm skin. These results do not support the hypothesis that significant K+ leaching from the stratum corneum into standing sweat is the cause for the previously reported elevated sweat [K+].

  7. 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.

  8. Formation of Reversible Solid Electrolyte Interface on Graphite Surface from Concentrated Electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Dongping; Tao, Jinhui; Yan, Pengfei; Henderson, Wesley A.; Li, Qiuyan; Shao, Yuyan; Helm, Monte L.; Borodin, Oleg; Graff, Gordon L.; Polzin, Bryant; Wang, Chong-Min; Engelhard, Mark; Zhang, Ji-Guang; De Yoreo, James J.; Liu, Jun; Xiao, Jie

    2017-02-10

    Interfacial phenomena have always been key determinants for the performance of energy storage technologies. The solid electrolyte interfacial (SEI) layer, pervasive on the surfaces of battery electrodes for numerous chemical couples, directly affects the ion transport, charge transfer and lifespan of the entire energy system. Almost all SEI layers, however, are unstable resulting in the continuous consumption of the electrolyte. Typically, this leads to the accumulation of degradation products on/restructuring of the electrode surface and thus increased cell impedance, which largely limits the long-term operation of the electrochemical reactions. Herein, a completely new SEI formation mechanism has been discovered, in which the electrolyte components reversibly self-assemble into a protective surface coating on a graphite electrode upon changing the potential. In contrast to the established wisdom regarding the necessity of employing the solvent ethylene carbonate (EC) to form a protective SEI layer on graphite, a wide range of EC-free electrolytes are demonstrated for the reversible intercalation/deintercalation of Li+ cations within a graphite lattice, thereby providing tremendous flexibility in electrolyte tailoring for battery couples. This novel finding is broadly applicable and provides guidance for how to control interfacial reactions through the relationship between ion aggregation and solvent decomposition at polarized interfaces.

  9. A study on the electrochemical behaviour of polypyrrole films in concentrated aqueous alkali halide electrolytes

    DEFF Research Database (Denmark)

    Jafeen, M. J. M.; Careem, M.A.; Skaarup, Steen

    2014-01-01

    The electrochemical behaviour of polypyrrole films doped with dodecyl benzene sulfonate (PPy/DBS) in LiCl aqueous electrolytes has been investigated in order to find the electrolyte concentration suitable for the operation of PPy/DBS-based soft actuators. For this investigation, PPy/DBS films...

  10. 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.

  11. Evaluation of plasma electrolyte concentration in pregnant Nigerian ...

    African Journals Online (AJOL)

    The renal function status in relation to electrolyte homeostasis was evaluated in a total of one hundred pregnant Nigerian women (volunteers) and thirty ... Nutrition, environmental condition and child's spacing may have influenced the parameters and their implications with respect to proper fetal development are discussed.

  12. Enhanced Cycling Stability of Rechargeable Li-O2 Batteries Using High Concentration Electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bin; Xu, Wu; Yan, Pengfei; Sun, Xiuliang; Bowden, Mark E.; Read, Jeffrey; Qian, Jiangfeng; Mei, Donghai; Wang, Chong M.; Zhang, Jiguang

    2016-01-26

    The electrolyte stability against reactive reduced-oxygen species is crucial for the development of rechargeable Li-O2 batteries. In this work, we systematically investigated the effect of lithium salt concentration in 1,2-dimethoxyethane (DME)-based electrolytes on the cycling stability of Li-O2 batteries. Cells with high concentration electrolyte illustrate largely enhanced cycling stability under both the full discharge/charge (2.0-4.5 V vs. Li/Li+) and the capacity limited (at 1,000 mAh g-1) conditions. These cells also exhibit much less reaction-residual on the charged air electrode surface, and much less corrosion to the Li metal anode. The density functional theory calculations are conducted on the molecular orbital energies of the electrolyte components and the Gibbs activation barriers for superoxide radical anion to attack DME solvent and Li+-(DME)n solvates. In a highly concentrated electrolyte, all DME molecules have been coordinated with salt and the C-H bond scission of a DME molecule becomes more difficult. Therefore, the decomposition of highly concentrated electrolyte in a Li-O2 battery can be mitigated and both air-cathodes and Li-metal anodes exhibits much better reversibility. As a results, the cyclability of Li-O2 can be largely improved.

  13. Effects of duty cycle and electrolyte concentration on the microstructure and biocompatibility of plasma electrolytic oxidation treatment on zirconium metal

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Shao-Fu [Department of Materials and Mineral Resources Engineering, Institute of Materials Science and Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China); Lou, Bih-Show [Chemistry Division, Center for General Education, Chang Gung University, Taoyuan 333, Taiwan (China); Yang, Yung-Chin [Department of Materials and Mineral Resources Engineering, Institute of Materials Science and Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China); Wu, Pei-Shan [Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan (China); Chung, Ren-Jei [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 10608, Taiwan (China); Lee, Jyh-Wei, E-mail: jefflee@mail.mcut.edu.tw [Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan (China); Center for Thin Film Technologies and Applications, Ming Chi University of Technology, New Taipei City 24301, Taiwan (China); Department of Electronic Engineering, Chang Gung University, Taoyuan 333, Taiwan (China)

    2015-12-01

    Recently, the plasma electrolytic oxidation (PEO) process has been widely studied and applied in the industrial setting due to its ability to create functional oxide layers on Al, Ti, Mg, and Zr alloys. In this work, a pulsed direct current (DC) power supply was adopted to grow the zirconia coating on pure Zr metal by PEO treatment. A fixed frequency of 1000 Hz and constant current of 2 A were used to fabricate all zirconia coatings. Duty cycle values of 25%, 75%, and 100% were used and 0.1 M K{sub 3}PO{sub 4} aqueous solution containing three different concentrations of KOH, 0.01, 0.05 and 0.1 M, was also used in fabrication. The plasma breakdown voltage decreased with increasing KOH concentration due to its higher electrolyte conductivity. The PEO oxide coating consisted of a thin continuous barrier layer and a thick porous outermost layer, which consisted of mainly monoclinic and minor tetragonal ZrO{sub 2} phases. The PEO treatment of Zr metal provided excellent corrosion resistance in Hank's solution and good biocompatibility for 3T3 and MG63 cells. These results suggest that PEO coatings having potential applications in the biomedical field were confirmed in this study. - Highlights: • Plasma electrolytic oxidation (PEO) treated coating consists of a continuous thin layer and a thick porous outermost layer. • The PEO coating thickness decreases with increasing content of KOH in electrolyte at duty cycles of 75% and 100%. • All PEO coatings provide good biocompatibility and no toxicity to both 3T3 and MG63 cells. • The PEO process greatly enhances the corrosion resistance of Zr metal to Hank's solution.

  14. 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.

  15. Effects of electrolyte concentration and current density on the ...

    Indian Academy of Sciences (India)

    2017-05-13

    May 13, 2017 ... HV with the increase of FeCl2 concentration in the plat- ing bath. The microhardness decreases rapidly when the concentration of FeCl2 is very low. The ionic strength of. Fe2+ increases with the increasing of FeCl2 concentration in the solution, and the concentration of Fe2+ in the cathode increases ...

  16. Comparison of interionic/intermolecular vibrational dynamics between ionic liquids and concentrated electrolyte solutions.

    Science.gov (United States)

    Fujisawa, Tomotsumi; Nishikawa, Keiko; Shirota, Hideaki

    2009-12-28

    In this study, we have compared the interionic/intermolecular vibrational dynamics of ionic liquids (ILs) and concentrated electrolyte solutions measured by femtosecond optically heterodyne-detected Raman-induced Kerr effect spectroscopy. A typical anion in ILs, bis(trifluoromethanesulfonyl)amide ([NTf(2)](-)), has been chosen as the anion for the sample ILs and concentrated electrolyte solutions. ILs used in this study are 1-butyl-3-methylimidazolium, 1-butylpyridinium, N-butyl-N,N,N-triethylammonium, and 1-butyl-1-methylpyrrolidinium with [NTf(2)](-). Li[NTf(2)] solutions (approximately 3.3 M) of water, methanol, propylene carbonate, and poly(ethylene glycol) have been selected as control samples. Kerr transients of the ILs and electrolyte solutions show intra- and interionic/intermolecular vibrational dynamics followed by slow picosecond overdamped relaxation. Fourier transform Kerr spectra have shown a difference in the relative intensities of intraionic vibrational bands of [NTf(2)](-) (280-350 cm(-1)) between the ILs and electrolyte solutions. The origin of the difference is attributed to the change in the conformational equilibrium between cisoid and transoid forms of [NTf(2)](-), which is caused by a favorable stabilization of dipolar cisoid form due to Li(+) and dipolar solvent molecules in the electrolyte solutions. Low-frequency Kerr spectra (0-200 cm(-1)) exhibit unique features with the variation of cation and solvent species. The aromatic ILs have a prominent high-frequency librational motion at about 100 cm(-1) in contrast to the case for the nonaromatic ones. The common structure of the spectra observed at about 20 cm(-1) likely comes from an interionic motion of [NTf(2)](-). The nonaromatic ILs allow a fair comparison with the electrolyte solutions of propylene carbonate and poly(ethylene glycol) because of the structural similarities. The comparison based on the first moment of the interionic/intermolecular vibrational spectrum suggests the

  17. Long term stability of Li-S batteries using high concentration lithium nitrate electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Brian DG; Carino, Emily V.; Connell, Justin G.; Han, Kee Sung; Cao, Ruiguo; Chen, Junzheng; Zheng, Jianming; Li, Qiuyan; Mueller, Karl T.; Henderson, Wesley A.; Zhang, Jiguang

    2017-10-01

    Lithium-sulfur (Li-S) battery is a very promising candidate for the next generation of energy storage systems required for electrical vehicles and grid energy storage applications due to its very high theoretical specific energy (2500 W h kg-1). However, the low coulombic efficiency (CE) during repeated Li plating/stripping of these processes have limited practical application of rechargeable Li-S batteries. In this work, a new electrolyte system based on high concentration of LiNO3 in diglyme solvent is developed which enables high CE of Li metal plating/stripping and high stability of Li anode in the sulfur containing electrolyte. Tailoring of electrolyte properties for the Li negative electrode has proven to be a successful strategy for improving the capacity retention and cycle life of Li-S batteries. This electrolyte provides a CE for Li plating/stripping of greater than 99% for over 200 cycles. In contrast, Li metal cycles for only less than 35 cycles at high CE in the standard 1 M LiTFSI + 2wt% LiNO3 in DOL:DME electrolyte under the same conditions. The stable Li metal anode enabled by the new electrolyte may accelerate the applications of high energy density Li-S batteries in both electrical vehicles and large-scale grid energy storage markets.

  18. Long term stability of Li-S batteries using high concentration lithium nitrate electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Brian D.; Carino, Emily V.; Connell, Justin G.; Han, Kee Sung; Cao, Ruiguo; Chen, Junzheng; Zheng, Jianming; Li, Qiuyan; Mueller, Karl T.; Henderson, Wesley A.; Zhang, Ji-Guang

    2017-10-01

    The lithium-sulfur (Li-S) battery is a very promising candidate for the next generation of energy storage systems required for electrical vehicles and grid energy storage applications due to its very high theoretical specific energy (2500 W h kg(-1)). However, low Coulombic efficiency (CE) during repeated Li metal plating/stripping has severely limited the practical application of rechargeable Li-S batteries. In this work, a new electrolyte system based on a high concentration of LiNO3 in diglyme (G2) solvent is developed which enables an exceptionally high CE for Li metal plating/stripping and thus high stability of the Li anode in the sulfur-containing electrolyte. The tailoring of electrolyte properties for the Li anode has proven to be a highly successful strategy for improving the capacity retention and cycle life of Li-S batteries. This electrolyte provides a CE of greater than 99% for over 200 cycles of Li plating/stripping. In contrast, the Li anode cycles for less than 35 cycles (with a high CE) in the state-of-the-art 1 M LiTFSI + 0.3 M LiNO3 in 1,3-dioxolane: 1,2-dimethoxyethane (DOL:DME) electrolyte under the same conditions. The stable Li anode enabled by the new electrolyte may accelerate the applications of high energy density Li-S batteries in both electrical vehicles and large-scale grid energy storage markets.

  19. Effects of electrolyte concentration and current density on the ...

    Indian Academy of Sciences (India)

    ... that upon increasing the concentration of FeCl 2 , initially the Fe content of the coating increased and then tended to be stable; the deposition rate and microhardness of coating decreased when the cathodic current efficiency ( η ) initially increased and then decreased; and for a FeCl 2 concentration of 3.6 gl − 1 , t h e c a t ...

  20. 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.

  1. Estimating Of Etchant Copper Concentration In The Electrolytic Cell Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Muzher M. Ibrahem

    2015-02-01

    Full Text Available In  this paper, Artificial Neural Networks (ANN, which are known for their ability to model nonlinear systems, provide accurate approximations of system behavior and are typically much more computationally efficient than phenomenological models  are used to predict the etchant copper concentration in the electrolytic cell in terms of electric potential, operating time, temperature of the electrolytic cell , ratio of surface area of poles per unit volume of solution  and the distance between poles. In this paper 350 sets of data are used to trained and test the network.. The best results were achieved using a model based on a feedforword Artificial Neural Network (ANN with one hidden layer and fifteen neurons in the hidden layer gives a very close prediction of the copper concentration in the electrolytic cell.

  2. THE EFFECT OF ELECTROLYTE CONCENTRATION AND PH ON THE FLOCCULATION AND RHEOLOGICAL BEHAVIOUR OF KAOLINITE SUSPENSIONS

    Directory of Open Access Journals (Sweden)

    M. S. NASSER

    2009-12-01

    Full Text Available The effects of the electrolyte concentration and pH on the settling behaviour, floc sizes and rheological behaviour of kaolinite suspensions were investigated. The results show that the settling behaviour of kaolinite changes with the ionic strength and pH of the suspension. In the acidic pH range, (pH 2 particles settle in flocculated form regardless of electrolyte concentration, however, in the basic pH range, the particles settle both, in dispersed form (at lower electrolyte concentrations and in flocculated form (at higher electrolyte concentrations. The Bingham yield stress and time-dependent behaviour for these flocculated and deflocculated suspensions was investigated. In this study, the fundamental of structural kinetic model (SKM was used to investigate the time-dependent viscosity behaviour of flocculated and deflocculated kaolinite suspensions. It was found that the kaolinite suspensions in the deflocculated form show viscosity time-independent behaviour with negligible Bingham yield stress. While, the flocculated suspensions show marked non-Newtonian time-dependent behaviour. This work has been very successful in establishing the link among particle-particle interactions, floc size, Bingham yield stress, breakdown rate constant, and extent of thixotropy.

  3. Optimization of an electrolyte conductivity detector for measuring low ion concentrations

    NARCIS (Netherlands)

    Timmer, B.H.; Sparreboom, Wouter; Olthuis, Wouter; Bergveld, Piet; van den Berg, Albert

    2002-01-01

    The optimization process of a planar interdigitated conductivity detector for measuring very low electrolyte concentrations for use in a lab-on-chip gas detection system is described. An electrical equivalent of the sensor is given, which includes the double layer capacitance dependency on the

  4. Evaluating Transport Properties and Ionic Dissociation of LiPF6 in Concentrated Electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhange; Higa, Kenneth; Han, Kee Sung; Srinivasan, Venkat

    2017-08-17

    The presence of lithium hexafluorophosphate (LiPF6) ion pairs in carbonate-based electrolyte solutions is widely accepted in the field of battery electrolyte research and is expected to affect solution transport properties. No existing techniques are capable of directly quantifying salt dissociation in these solutions. Previous publications by others have provided estimates of dissociation degrees using dilute solution theory and pulsed field gradient nuclear magnetic resonance spectroscopy (PFG-NMR) measurements of self-diffusivity. However, the behavior of a concentrated electrolyte solution can deviate significantly from dilute solution theory predictions. This work, for the first time, instead uses Onsager–Stefan–Maxwell concentrated solution theory and the generalized. Darken relation with PFG-NMR measurements to quantify the degrees of dissociation in electrolyte solutions (LiPF6 in ethylene carbonate/diethyl carbonate, 1:1 by weight). At LiPF6 concentrations ranging from 0.1 M to 1.5 M, the salt dissociation degree is found to range from 61% to 37%. Transport properties are then calculated through concentrated solution theory with corrections for these significant levels of ion pairing.

  5. Influence of ion sterics on diffusiophoresis and electrophoresis in concentrated electrolytes

    Science.gov (United States)

    Stout, Robert F.; Khair, Aditya S.

    2017-01-01

    We quantify the diffusiophoresis and electrophoresis of a uniformly charged, spherical colloid in a binary electrolyte using modified Poisson-Nernst-Planck equations that account for steric repulsion between finite sized ions. Specifically, we utilize the Bikerman (Bik) lattice gas model and the Carnahan-Starling (CS) and Boublik-Mansoori-Carnahan-Starling-Leland (BMCSL) equations of state for monodisperse and polydisperse, respectively, hard spheres. We compute the phoretic mobility for weak applied fields using an asymptotic approach for thin diffuse layers, where ion steric effects are expected to be most prevalent. The thin diffuse layer limit requires λD/R →0 , where λD is the Debye screening length and R is the particle radius; this limit is readily attained for micron-sized colloids in concentrated electrolytic solutions. It is well known that the classic Poisson-Boltzmann (PB) model for pointlike, noninteracting ions leads to a prediction of a maximum in both the diffusiophoretic and electrophoretic mobilities with increasing particle zeta potential (at fixed λD/R ). In contrast, we find that ion sterics essentially eliminate this maximum (for reasonably attainable zeta potentials) and increase the mobility relative to PB. Next, we consider the more experimentally relevant case of a particle with a constant surface charge density and vary the electrolyte concentration, neglecting charge regulation on surface active sites. Rather surprisingly, there is little difference between the predictions of the four models (PB, Bik, CS, and BMCSL) for electrophoretic mobility in concentrated solutions, at reasonable surface charge densities (˜1 -10 μ C /cm2 ). This is because as the concentration increases, the zeta potential is reduced (to below the thermal voltage for concentrations above about 1 M) and therefore the diffuse layer structure is largely unaffected by ion sterics. For gradients of symmetric electrolytes (equal diffusivities, charge, and size

  6. A molecular dynamic model for analyzing concentrations of electrolytes: Fractional molar dependences of microstructure properties

    Science.gov (United States)

    Khalansky, D.; Popova, E.; Gladyshev, P.; Dushanov, E.; Kholmurodov, Kh.

    2014-12-01

    electrolyte concentration: 16, 8, and 1 mol/kg. Energies of diffusion activation are calculated using the Arrhenius equation, thereby constructing temperature dependence graphs of diffusion coefficients for all four electrolyte systems. The observed diffusion properties of the electrolyte systems are found to correlate well with the energy and structural radial distribution data.

  7. 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.

  8. Experimental Study of Hydroxy Gas (HHO) Production with Variation in Current, Voltage and Electrolyte Concentration

    Science.gov (United States)

    Alam, Noor; Pandey, K. M.

    2017-08-01

    In this paper, work has been carried out experimentally for the investigation of the effects of variation incurrent, voltage, temperature, chemical concentration and reaction time on the amount of hydroxy gas produced. Further effects on the overall electrolysis efficiency of advance alkaline water is also studied. The hydroxy gas (HHO) has been produced experimentally by the electrolysis of alkaline water with parallel plate electrode of 316L-grade stainless steel. The electrode has been selected on the basis of corrosion resistance and inertness with respect to electrolyte (KOH). The process used for the production of HHO is conventional as compared to the other production processes because of reduced energy consumption, less maintenance and low setup cost. From the experimental results, it has been observed that with increase in voltage, temperature and electrolyte concentration of alkaline solution, the production of hydroxy gas has increased about 30 to 40% with reduction in electrical energy consumption.

  9. 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.

  10. Effects of surfactant and electrolyte concentrations on bubble formation and stabilization.

    Science.gov (United States)

    Xu, Qingyi; Nakajima, Mitsutoshi; Ichikawa, Sosaku; Nakamura, Nobutaka; Roy, Poritosh; Okadome, Hiroshi; Shiina, Takeo

    2009-04-01

    As interest in the application of microbubbles grows, it is becoming increasingly important to understand the factors affecting their formation and properties in order to effectively generate microbubbles. This paper investigates the effect of surfactant concentration and electrolyte addition on the size distribution and stability of microbubbles. The anionic surfactant sodium dodecyl sulfate (SDS) was used as the surfactant. Minimum bubble diameter and maximum stability were achieved at surfactant concentrations above the CMC. The effect of the electrolyte addition was studied by adding sodium chloride (NaCl) at an SDS concentration below the critical micelle concentration (CMC). Addition of NaCl decreased bubble size and improved bubble preparation to a certain extent. The addition of salt at low concentrations did not affect the surface tension; however, the surface tension was reduced as salt concentration was increased and reached a constant value for NaCl concentrations above 0.25%. The presence of NaCl resulted in a significant decrease in zeta-potential, implying a reduction in the surface charge of SDS micelles. This result suggests that the presence of NaCl may improve the generation and stability of bubbles by enhancing the structures of the adsorption monolayer and interfacial film.

  11. Liquid Structure with Nano-Heterogeneity Promotes Cationic Transport in Concentrated Electrolytes.

    Science.gov (United States)

    Borodin, Oleg; Suo, Liumin; Gobet, Mallory; Ren, Xiaoming; Wang, Fei; Faraone, Antonio; Peng, Jing; Olguin, Marco; Schroeder, Marshall; Ding, Michael S; Gobrogge, Eric; von Wald Cresce, Arthur; Munoz, Stephen; Dura, Joseph A; Greenbaum, Steve; Wang, Chunsheng; Xu, Kang

    2017-10-24

    Using molecular dynamics simulations, small-angle neutron scattering, and a variety of spectroscopic techniques, we evaluated the ion solvation and transport behaviors in aqueous electrolytes containing bis(trifluoromethanesulfonyl)imide. We discovered that, at high salt concentrations (from 10 to 21 mol/kg), a disproportion of cation solvation occurs, leading to a liquid structure of heterogeneous domains with a characteristic length scale of 1 to 2 nm. This unusual nano-heterogeneity effectively decouples cations from the Coulombic traps of anions and provides a 3D percolating lithium-water network, via which 40% of the lithium cations are liberated for fast ion transport even in concentration ranges traditionally considered too viscous. Due to such percolation networks, superconcentrated aqueous electrolytes are characterized by a high lithium-transference number (0.73), which is key to supporting an assortment of battery chemistries at high rate. The in-depth understanding of this transport mechanism establishes guiding principles to the tailored design of future superconcentrated electrolyte systems.

  12. Diurnal variation of plasma concentrations of cortisol, aldosterone and electrolytes in the ram.

    Science.gov (United States)

    Mesbah, S; Brudieux, R

    1982-06-01

    The peripheral plasma concentrations of cortisol, aldosterone and electrolytes were measured simultaneously in 2 groups of 20 + 8 rams sampled respectively every 3 hours in June 1974 and hourly in June 1975 over a 24-hr period, in the Algiers area. In spite of large individual variations, the mean plasma concentrations of cortisol and aldosterone exhibited synchronous diurnal changes: they were highest in the morning, decreased during the afternoon until 18.00 h, and remained lowest during the first part of the night.

  13. 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...

  14. The assessment of early glycosaminoglycan concentration changes in the kidney of diabetic rats by critical electrolyte concentration staining.

    Science.gov (United States)

    Pourghasem, Mohsen; Nasiri, Ebrahim; Sum, Shima; Shafi, Hamid

    2013-01-01

    Glycosaminoglycan (GAG) has a pivot role in renal function and homeostasis. Analysis of GAG amount generally serves to determine GAG alteration due to diabetes mellitus. Critical Electrolyte Concentration (CEC) staining can be an efficacy method to study GAG amount changes. Based on an experimental study, 20 male rats were randomly divided equally into two experimental and control groups. Diabetes mellitus was induced by a single sub cutaneous injection (120 mg/kg) of alloxan monohydrate. After 8 weeks, diabetic kidneys were paraffin embedded and sectioned at 5μm on a microtome. Slides were prepared and studied after staining by Critical Electrolyte Concentration (CEC 1 -4). In this study, we succeeded to show a decrease of hyaluronic acid and chondroitin sulfate concentration in diabetic kidney at 8 weeks diabetic rats which are earlier signs compared to those reported previously. In contrary, no significant changes in heparin sulfate and keratin sulfate have been seen. Diabetic nephropathy is a progressive disease and earlier diagnosis makes a better treatment design to reduce its development. CEC staining is able to determine degradation of hyaluronic acid and chondroitin sulfate synthesis in diabetic kidney of rats in an earlier time.

  15. Electrodeposited NiCoFe films from electrolytes with different Fe ion concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Kockar, Hakan, E-mail: hkockar@balikesir.edu.tr [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey); Demirbas, Ozen, E-mail: ozendemirbas@hotmail.com [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey); Kuru, Hilal, E-mail: htopcu@balikesir.edu.tr [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey); Alper, Mursel, E-mail: malper@uludag.edu.tr [Uludag Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, 16059 Gorukle, Bursa (Turkey); Karaagac, Oznur, E-mail: karaagac@balikesir.edu.tr [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey); Haciismailoglu, Murside, E-mail: msafak@uludag.edu.tr [Uludag Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, 16059 Gorukle, Bursa (Turkey); Ozergin, Ercument, E-mail: ercumentz@yahoo.com [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey)

    2014-06-01

    Ternary NiCoFe films, relating their magnetic and magnetoresistance properties with film composition, and the corresponding crystal structure were investigated in terms of different Fe ion concentrations in the electrolyte. The current–time transients were recorded to control the growth of proper films. The film composition by energy dispersive X-ray spectroscopy revealed that as the Fe ion concentration in the electrolyte was increased, the Fe and Co contents in the films increased and Ni content decreased. From the structural analysis by X-ray diffraction, all films had a face-centred cubic structure and, no reflection from body-centred cubic (bcc) Fe was existed in all samples due to <12 at% Fe. The saturation magnetisation increased from 865 emu/cm{sup 3} to 1080 emu/cm{sup 3} and the coercivities decreased from 60 Oe to 13 Oe with increasing Fe and Co contents and decreasing Ni content in the films. All NiCoFe films showed anisotropic magnetoresistance. The longitudinal magnetoresistance magnitudes decreased from 6.3% to 2.2% with increasing Fe and Co contents and decreasing Ni in the films while the magnitudes of transverse magnetoresistance stayed almost constant at ∼5.0%. The variations in magnetic and magnetoresistive properties related to the crystal structure were attributed to the compositional changes caused by the variation of the Fe ion concentration in the electrolyte. - Highlights: • Structural and magnetic properties of electrodeposited NiCoFe films were studied. • The Fe and Co increased and Ni decreased with increasing Fe concentration. • All films had a face-centred cubic structure irrespective of the film content. • The M{sub s} increased and H{sub c} decreased with the change of film content. • All films showed AMR.

  16. The effects of surfactant and electrolyte concentrations on the size of nanochitosan during storage

    Science.gov (United States)

    Primaningtyas, Annisa; Budhijanto, Wiratni; Fahrurrozi, Mohammad; Kusumastuti, Yuni

    2017-05-01

    The nano-sized particle of chitosan (nanochitosan) is a potential natural preservative agent for fresh fish and fish product preservation. Theoretically, nano-sized particles exert strong van der Waals force to each other so that the problem associated with nanochitosan is agglomeration that leads to size instability during storage. Size stability is of importance in the application of nanochitosan as an antimicrobial agent because it considerably affects the antimicrobial activity of chitosan. In this study, the formulation of nanochitosan was optimized with respect to the two major factors in colloid dispersion theory, which were the presence of surfactant and electrolyte. Polysorbate-80 was chosen as the representative of food grade surfactant while NaCl was used as the electrolyte. The purposes of this study were to evaluate the effect of polysorbate-80 concentration and to determine the effect of NaCl ions on the particle size of nanochitosan for at least one month storage period. Data were analyzed using Analysis of Variance (ANOVA) to identify the factors significantly affect the size stability. The dynamics of particle size distribution during storage was measured by Particle Size Analyzer (PSA). The result showed that surfactant did not significantly affect the particle size stability. On the other hand, the addition of electrolyte into the colloidal dispersion of nanochitosan consistently stabilized and also narrowed the particle size distribution during storage in the range of 175-391 nm.

  17. Effects of electrolyte concentration and counterion valence on the microstructural flow regimes in dilute cetyltrimethylammonium tosylate micellar solutions.

    Science.gov (United States)

    Tepale, N; Macías, E R; Bautista, F; Puig, J E; Manero, O; Gradzielski, M; Escalante, J I

    2011-11-15

    The shear thickening behavior and the transition to shear thinning are examined in dilute cetyltrimethylammonium tosylate (CTAT) micellar solutions as a function of surfactant concentration and ionic strength using electrolytes with different counterion valence. Newtonian behavior at low shear rates, followed by shear thickening and shear thinning at higher shear rates, are observed at low and intermediate surfactant and electrolyte concentrations. Shear thickening diminishes with increasing surfactant concentration and ionic strength. At higher surfactant or electrolyte concentration, only a Newtonian region followed by shear thinning is detected. A generalized flow diagram indicates two controlling regimes: one in which electrostatic screening dominates and induces micellar growth, and another, at higher electrolyte and surfactant concentrations, where chemical equilibrium among electrolyte and surfactant counterions controls the rheological behavior by modifying micellar breaking and reforming. Analysis of the shear thickening behavior reveals that not only a critical shear rate is required for shear thickening, but also a critical deformation, which appears to be unique for all systems examined, within experimental error. Moreover, a superposition of the critical shear rate for shear thickening with surfactant and electrolyte concentration is reported. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. 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.

  19. 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.

  20. A Preliminary Study on the Measurement of Sediment Concentration in Hill-Slope Runoff with an Electrolyte Tracer

    Directory of Open Access Journals (Sweden)

    Xiaonan Shi Fan Zhang

    2012-01-01

    Full Text Available Sediment concentration in hill-slope runoff is an important index for soil erosion. Developing a reliable and portable measuring system of sediment concentration is a core issue for soil and water conservation study, especially for the Tibetan Plateau under unfavorable climate and terrain conditions for field investigation. Challenges include uneven distribution of sediment across a runoff section as well as difficulty in detecting a wide range of particle sizes. An electrolyte tracer, with the advantage of uniform distribution and its widely used electric-conductivity sensor, can avoid the problems of direct measurement of sediment. A new measurement method of sediment concentration in runoff with an electrolyte tracer is proposed based on a premise that sediment concentration is closely correlated with hydrodynamic dispersion coefficient of solute in runoff. In this study, an experiment system of hill-slope runoff with an electrolyte tracer and sediments is first designed. Second, two model parameters in the advective-dispersive equation of solute transport, flow velocity and diffusion coefficient, are inversely estimated by calibrating the observed concentrations of an electrolyte tracer. And third, the relationship between sediment concentrations and hydrodynamic dispersion coefficients are defined through specified regression. As a result, a measurement system of sediment concentration in hill-slope runoff with an electrolyte tracer is primarily established by integrating the relationship of variables, experiment system, and model theory.

  1. 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.

  2. 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

  3. Analysis of the electrolyte convection inside the concentration boundary layer during structured electrodeposition of copper in high magnetic gradient fields.

    Science.gov (United States)

    König, Jörg; Tschulik, Kristina; Büttner, Lars; Uhlemann, Margitta; Czarske, Jürgen

    2013-03-19

    To experimentally reveal the correlation between electrodeposited structure and electrolyte convection induced inside the concentration boundary layer, a highly inhomogeneous magnetic field, generated by a magnetized Fe-wire, has been applied to an electrochemical system. The influence of Lorentz and magnetic field gradient force to the local transport phenomena of copper ions has been studied using a novel two-component laser Doppler velocity profile sensor. With this sensor, the electrolyte convection within 500 μm of a horizontally aligned cathode is presented. The electrode-normal two-component velocity profiles below the electrodeposited structure show that electrolyte convection is induced and directed toward the rim of the Fe-wire. The measured deposited structure directly correlates to the observed boundary layer flow. As the local concentration of Cu(2+) ions is enhanced due to the induced convection, maximum deposit thicknesses can be found at the rim of the Fe-wire. Furthermore, a complex boundary layer flow structure was determined, indicating that electrolyte convection of second order is induced. Moreover, the Lorentz force-driven convection rapidly vanishes, while the electrolyte convection induced by the magnetic field gradient force is preserved much longer. The progress for research is the first direct experimental proof of the electrolyte convection inside the concentration boundary layer that correlates to the deposited structure and reveals that the magnetic field gradient force is responsible for the observed structuring effect.

  4. 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.

  5. Optimization of hybrid polymer electrolytes with the effect of lithium salt concentration in PEO/PVdF-HFP blends

    Energy Technology Data Exchange (ETDEWEB)

    Pradeepa, P.; Edwin raj, S.; Sowmya, G.; Kalaiselvimary, J.; Ramesh Prabhu, M., E-mail: mkram83@gmail.com

    2016-03-15

    Highlights: • Polymer blends based on PVdF-HFP/PEO were prepared for Li-ion battery applications. • Structural and electrochemical studies were carried out on prepared electrolytes. • The electrolytes can be used as electrolyte in the possible device fabrications. - Abstract: Poly(ethylene oxide) (PEO) 6.25 wt%/poly(vinylidene fluoride-co-hexafluoropropylene) [P(VdF-HFP)] 18.75 wt% blend based electrolyte films containing different concentrations (2–10) wt% of lithium salt were prepared. The miscibility studies have been performed by using X-ray diffraction and Fourier transform infrared spectroscopy. The role of interaction between polymer hosts on conductivity is discussed using the results of a.c. impedance studies. A room temperature conductivity of 2.3912 × 10{sup −4} S cm{sup −1} has been obtained for PEO (6.25)–PVdF-HFP (18.75)–LiClO{sub 4} (8)–PC (67) polymer complex. The temperature dependence of the conductivity of polymer electrolyte seems to obey VTF relation. Electrochemical stability (3.3 V) was observed in the prepared polymer electrolyte. Reduction process and oxidation process of the prepared electrolyte system have also been evaluated by means of cyclic voltammetry. Thermogravimetric analysis results indicate thermal stability of PEO/PVdF-HFP lithium salt complexes. Roughness parameter of the sample having maximum ionic conductivity was studied by AFM. The morphology of the polymer complex is investigated by using SEM.

  6. 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.

  7. Effects of freshwater housing and fluid types on aquatic bird serum electrolyte concentrations.

    Science.gov (United States)

    Frankfurter, Greg; Ziccardi, Michael H; Massey, J Gregory

    2012-12-01

    Recent seabird mass morbidity events have highlighted the need to elucidate the effects of freshwater and hypertonic saline use for fluid therapy and housing in captive aquatic birds. Serum electrolyte concentrations of northern fulmars (Fulmarus glacialis; n = 9), western grebes (Aechmophorus occidentalis; n = 6), and common murres (Uria aalge; n = 25) housed on freshwater while undergoing rehabilitation at the San Francisco Bay Oiled Wildlife Care and Education Center in Fairfield, California, were compared to reference intervals from free-ranging populations. Additionally, northern fulmars were given intermittent oral boluses of hypertonic saline. In birds housed on freshwater, there were significant decreases in serum sodium and chloride, with 44% of northern fulmars and 72% of common murres falling below the established reference interval. All of the western grebes were able to maintain serum sodium and chloride within the reference intervals. The significance of these findings reflect the behavior and natural history of the species studied. The physiologic regulation of salt by the salt glands, gastrointestinal tract, and renal systems of seabirds, along with their behavior and natural history, should be considered when working with these birds in a rehabilitation or captive setting. Salt supplementation is necessary for some species of seabirds. Monitoring of serum electrolytes should be used for individual animals or salt supplementation should be considered in holopelagic species.

  8. 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.

  9. Adsorption behavior of low concentration carbon monoxide on polymer electrolyte fuel cell anodes for automotive applications

    Science.gov (United States)

    Matsuda, Yoshiyuki; Shimizu, Takahiro; Mitsushima, Shigenori

    2016-06-01

    The adsorption behavior of CO on the anode around the concentration of 0.2 ppm allowed by ISO 14687-2 is investigated in polymer electrolyte fuel cells (PEFCs). CO and CO2 concentrations in the anode exhaust are measured during the operation of a JARI standard single cell at 60 °C cell temperature and 1000 mA cm-2 current density. CO coverage is estimated from the gas analysis and CO stripping voltammetry. The cell voltage decrease as a result of 0.2 ppm CO is 29 mV and the CO coverage is 0.6 at the steady state with 0.11 mg cm-2 of anode platinum loading. The CO coverage as a function of CO concentration approximately follows a Temkin-type isotherm. Oxygen permeated to the anode through a membrane is also measured during fuel cell operation. The exhaust velocity of oxygen from the anode was shown to be much higher than the CO supply velocity. Permeated oxygen should play an important role in CO oxidation under low CO concentration conditions.

  10. 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.

  11. Effects of Hypoxia on the Behaviour, Mortality and Plasma Electrolyte Concentrations of Goldlined Seabream, Rhabdosargus sarba

    Directory of Open Access Journals (Sweden)

    Hamed M. Al-Gheilani

    2008-01-01

    Full Text Available The behaviour, mortality rates and plasma electrolyte concentrations of goldlined seabream Rhabdosargus sarba challenged with low dissolved oxygen (DO conditions was studied in an experimental setup, comprising a control (7.9 ml/l DO and two hypoxic (2 ml/l and 1 ml/l DO treatments. Increased ventilation rates and decreased swimming activity were observed in hypoxic treatments, but some fish exhibited strenuous avoidance actions. No mortalities were observed after 3 h, 6 h, or 24 h, but 50% of males and 18% of females died in the 48 h treatment at 1 ml/l DO. The mean size of surviving fish (305± 32.1 g total weight was significantly smaller than those that died (425 ± 33.1 g. The plasma concentrations of Na+, Cl- and Mg2+ did not vary significantly relative to treatment, exposure time, fish size and gender, or interactions among treatment, time and gender. Ca2+ concentrations increased significantly after 48 h at 1 ml/l, but this result may be artificial because of the small sample size. The results suggest that R. sarba is comparatively tolerant of the low oxygen or hypoxic conditions that often occur in the coastal waters of Oman, where seasonal upwellings and  high primary productivity have in the past caused mass mortalities of demersal fishes.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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 ...

  18. 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.

  19. Quantitative Visualization of Salt Concentration Distributions in Lithium-Ion Battery Electrolytes during Battery Operation Using X-ray Phase Imaging.

    Science.gov (United States)

    Takamatsu, Daiko; Yoneyama, Akio; Asari, Yusuke; Hirano, Tatsumi

    2018-02-07

    A fundamental understanding of concentrations of salts in lithium-ion battery electrolytes during battery operation is important for optimal operation and design of lithium-ion batteries. However, there are few techniques that can be used to quantitatively characterize salt concentration distributions in the electrolytes during battery operation. In this paper, we demonstrate that in operando X-ray phase imaging can quantitatively visualize the salt concentration distributions that arise in electrolytes during battery operation. From quantitative evaluation of the concentration distributions at steady states, we obtained the salt diffusivities in electrolytes with different initial salt concentrations. Because of no restriction on samples and high temporal and spatial resolutions, X-ray phase imaging will be a versatile technique for evaluating electrolytes, both aqueous and nonaqueous, of many electrochemical systems.

  20. 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

  1. Stabilization of Silicon Carbide (SiC) micro- and nanoparticle dispersions in the presence of concentrated electrolyte.

    Science.gov (United States)

    Vilinska, Annamaria; Ponnurangam, Sathish; Chernyshova, Irina; Somasundaran, Ponisseril; Eroglu, Damla; Martinez, Jose; West, Alan C

    2014-06-01

    Achieving a stable and robust dispersion of ultrafine particles in concentrated electrolytes is challenging due to the shielding of electrostatic repulsion. Stable dispersion of ultrafine particles in concentrated electrolytes is critical for several applications, including electro-codeposition of ceramic particles in protective metal coatings. We achieved the steric stabilization of SiC micro- and nano-particles in highly concentrated electroplating Watts solutions using their controlled coating with linear and branched polyethyleneimines (PEI) as dispersants. Branched polyethyleneimine of 60,000 MW effectively disperses both microparticles and nanoparticles at a concentration of 1000 ppm. However, lower polymer dosages and smaller polymers fail to disperse, presumably due to insufficient coverage and bridging flocculation. Dispersion stability correlates well with the adsorption density of PEI on microparticles. We discuss the results in the framework of DLVO theory and suggest possible dispersion mechanisms. However, though the dispersion is enhanced with extended adsorption time, the residual PEI in solution adversely affects electroplating. We overcome this drawback by precoating the particles with the polymer and resuspending them in Watts solution. With this novel approach, we obtained robust dispersions. These results offer new possibilities to control dispersion at high electrolyte concentration, as well as bring new insights into the dispersion phenomenon. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Concurrent aggregation and transport of graphene oxide in saturated porous media: Roles of temperature, cation type, and electrolyte concentration.

    Science.gov (United States)

    Wang, Mei; Gao, Bin; Tang, Deshan; Yu, Congrong

    2018-01-02

    Simultaneous aggregation and retention of nanoparticles can occur during their transport in porous media. In this work, the concurrent aggregation and transport of GO in saturated porous media were investigated under the conditions of different combinations of temperature, cation type (valence), and electrolyte concentration. Increasing temperature (6-24 °C) at a relatively high electrolyte concentration (i.e., 50 mM for Na + , 1 mM for Ca 2+ , 1.75 mM for Mg 2+ , and 0.03 and 0.05 mM for Al 3+ ) resulted in enhanced GO retention in the porous media. For instance, when the temperature increased from 6 to 24 °C, GO recovery rate decreased from 31.08% to 6.53% for 0.03 mM Al 3+ and from 27.11% to 0 for 0.05 mM Al 3+ . At the same temperature, increasing cation valence and electrolyte concentration also promoted GO retention. Although GO aggregation occurred in the electrolytes during the transport, the deposition mechanisms of GO retention in the media depended on cation type (valence). For 50 mM Na + , surface deposition via secondary minima was the dominant GO retention mechanism. For multivalent cation electrolytes, GO aggregation was rapid and thus other mechanisms such as physical straining and sedimentation also played important roles in controlling GO retention in the media. After passing through the columns, the GO particles in the effluents showed better stability with lower initial aggregation rates. This was probably because less stable GO particles with lower surface charge densities in the porewater were filtered by the porous media, resulting in more stable GO particle with higher surface charge densities in the effluents. An advection-dispersion-reaction model was applied to simulate GO breakthrough curves and the simulations matched all the experimental data well. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The black and white coatings on Ti-6Al-4V alloy or pure titanium by plasma electrolytic oxidation in concentrated silicate electrolyte

    Science.gov (United States)

    Han, Jun-xiang; Cheng, Yu-lin; Tu, Wen-bin; Zhan, Ting-Yan; Cheng, Ying-liang

    2018-01-01

    Black TiO2 has triggered scientific interest due to its unique properties such as enhanced solar-driven photocatalytic activity. In this paper, plasma electrolytic oxidation (PEO) treatment of Ti-6Al-4V alloy has been carried out in concentrated sodium silicate electrolyte. Silica-based black and white TiO2 coatings respectively have been obtained by controlling the oxidation time. The black coating, which was formed with a short treatment time, shows good corrosion resistance and the black appearance can be attributed to the presence of Ti2+ and Ti3+ in the coating. The lower valence titanium ions are absent in the white coatings and they also contain relatively higher Na content compared to the black coatings. The white coatings have great surface roughnesses and super hydrophilicity. The bonding strengths of the black and white coatings on the Ti-6Al-4V alloy are ∼14.4 and 4.3 MPa, respectively. The vanadium contributes little to the black appearance of the coating on Ti6Al4V alloy, since the same phenomena occur for the PEO of a pure titanium substrate.

  4. Evaluation of physical stability of all in one parenteral admixtures for pediatric home care with high electrolytes concentrations.

    Science.gov (United States)

    Watrobska-Swietlikowska, Dorota; Szlagatys-Sidorkiewicz, Agnieszka; Łuszkiewicz, Katarzyna

    2014-01-01

    The aim of the study was to evaluate stability of 48 total parenteral admixtures for pediatric patients who require home parenteral nutrition. Admixtures contain high amounts of electrolytes. In a clinical practice electrolytes-enrichment of the parenteral nutrition admixtures is a usual demand, especially on the neonatal/pediatric wards. The supplementation of parenteral nutrition with high concentration of electrolytes is a living problem due to decreased stability of lipid emulsions in nutrition admixtures caused by bivalent cations. Preliminary admixtures were prepared in two-chamber ethylene vinyl acetate bags: amino acids, glucose and electrolytes were combined in one chamber and 20% (w/w) lipid emulsions (SMOFlipid®, Intralipid ® or ClinOleic®) were placed separately in the second chamber. Organic salts of calcium and phosphates were used. Pre-admixtures were stored at +4ºC for up to 21 days after preparation. Each composition of admixtures was prepared twice, because contents of the two chambers were combined at t=0 or after 21 days of storage at +4ºC. Visual observations, globule size distribution (using optical microscopy, laser diffraction and photon correlation spectroscopy methods), pH analyses, zeta potential and surface tension were performed after combining all components together with vitamins. Among 48 of investigated admixtures only two were problematic and other may be stored for at least 21 days at 4°C and completed admixtures demonstrated stability for at least 24 h at room temperature. It was possible to obtain stable admixtures despite of the high concentration of electrolytes. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  5. [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.

  6. 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 ...

  7. 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.

  8. The Influence of Electrolytic Concentration on the Electrochemical Deposition of Calcium Phosphate Coating on a Direct Laser Metal Forming Surface

    Directory of Open Access Journals (Sweden)

    Qianyue Sun

    2017-01-01

    Full Text Available A calcium phosphate (CaP coating on titanium surface enhances its biocompatibility, thus facilitating osteoconduction and osteoinduction with the inorganic phase of the human bone. Electrochemical deposition has been suggested as an effective means of fabricating CaP coatings on porous surface. The purpose of this study was to develop CaP coatings on a direct laser metal forming implant using electrochemical deposition and to investigate the effect of electrolytic concentration on the coating’s morphology and structure by X-ray diffraction, scanning electron microscopy, water contact angle analysis, and Fourier transform infrared spectroscopy. In group 10−2, coatings were rich in dicalcium phosphate, characterized to be thick, layered, and disordered plates. In contrast, in groups 10−3 and 10−4, the relatively thin and well-ordered coatings predominantly consisted of granular hydroxyapatite. Further, the hydrophilicity and cell affinity were improved as electrolytic concentration increased. In particular, the cells cultured in group 10−3 appeared to have spindle morphology with thick pseudopodia on CaP coatings; these spindles and pseudopodia strongly adhered to the rough and porous surface. By analyzing and evaluating the surface properties, we provided further knowledge on the electrolytic concentration effect, which will be critical for improving CaP coated Ti implants in the future.

  9. Application of Electro-Oxidation Method for Treatment of Dye Textile Wastewater Using Stainless Steel Electrode: Study of Electrolyte Concentration Effect to Color Removal

    Directory of Open Access Journals (Sweden)

    Jumardin Rua

    2017-09-01

    Full Text Available The increasing number of textile industries has created a new problem of environmental pollution from waste produced. Entering of concentrated wastewater that containing of complex organic compounds to agricultural land and rivers has caused loss to humans or the environment. Treatment of dye textile wastewater by electro-oxidation method using stainless steel electrode has been done. This research consists of several stages: analysis of electrode composition with SEM-EDX, electrolysis of wastewater at variation of electrolyte concentration and analysis of electrolyte concentration effect to color removal percentage of wastewater. The result shows that the electrode composition consisted of iron, chromium, nickel and silica with the main composition of iron in the amount of 72.2%. After electrolysis on variations of electrolyte concentration and analysis of color removal percentage of wastewater, obtained that the largest of color removal percentage on the use of electrolyte concentration of 3% in the amount of 98.81%

  10. Hydronium-dominated ion transport in carbon-dioxide-saturated electrolytes at low salt concentrations in nanochannels

    DEFF Research Database (Denmark)

    Lund Jensen, Kristian; Kristensen, Jesper Toft; Crumrine, Andrew Michael

    2011-01-01

    the nanochannel conductance at low salt concentrations and identify a conductance minimum before saturation at a value independent of salt concentration in the dilute limit. Via the Poisson-Boltzmann equation, our model self-consistently couples chemical-equilibrium dissociation models of the silica wall...... and of the electrolyte bulk, parametrized by the dissociation reaction constants. Experimental data with aqueous KCl solutions in 165-nm-high silica nanochannels are described well by our model, both with and without extra hydronium from added HCl....

  11. 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

  12. Critical electrolyte concentration of chromatin in polytene chromosomes of Trichosia pubescens (Diptera, Sciaridae

    Directory of Open Access Journals (Sweden)

    Ana Lúcia P. Monteiro

    1998-06-01

    Full Text Available The binding of toluidine blue molecules to nucleic acid phosphates under conditions of competition with Mg2+ ions was studied in Trichosia pubescens polytene chromosome regions differing in composition and organization (RNA-rich areas and puffs, DNA puffs, heterochromatin. The aim was to find variability in the Mg2+ concentration at which metachromasy was completely prevented (= critical electrolyte concentration; CEC and that could reflect differences at the level of nucleoprotein complexes in particular chromosome regions and developmental phases. Although high CEC values have been found in tightly packed chromatin such as that of heterochromatin zones, the CEC values for the other regions have proven to be affected not only by availability and proximity of DNA phosphates but also by RNA richness and other factors. Among these, changes in DNA geometry and packing state have been assumed for explaining increased values after RNA removal in DNA puffs and RNA-rich zones. Based on CEC values it has been suggested that alterations at the level of nucleoprotein complexes may occur in puffs before they are morphologically detectable. CEC results for polytene chromosomes were thus revealed to vary considerably with slight variations in nucleoprotein composition and organization. However, since a complex and apparently contradictory rationale has to be used for explaining part of the results, CEC is not recommended as a useful tool for extensive and comparative studies of this particular model.A ligação de moléculas de azul de toluidina a grupamentos fosfatos de ácido nucléico em condições de competição com íons Mg2+ foi estudada em regiões de cromossomos politênicos de Trichosia pubescens que diferem em composição e organização (áreas ricas em RNA, pufes de RNA e DNA, heterocromatina. O objetivo foi encontrar variabilidade na concentração de Mg2+ na qual a metacromasia fosse completamente abolida (= concentração crítica de eletr

  13. Sodium Aluminate Concentration Effects on Microstructure and Corrosion Behavior of the Plasma Electrolytic Oxidation Coatings on Pure Titanium

    Science.gov (United States)

    Molaei, Maryam; Fattah-Alhosseini, Arash; Gashti, Seyed Omid

    2017-11-01

    Sodium aluminate (NaAlO2) concentration was varied in order to understand the influence of the chemical composition of electrolyte on the spark characteristics, microstructure, and corrosion behavior of plasma electrolytic oxidation (PEO) coatings. For this purpose, PEO coatings were formed on the pure titanium substrate surface using solutions of four diverse sodium aluminate concentrations (6, 8, 10, and 12 g/L). The PEO process was carried out at constant time and voltage (180 seconds and 420 V). Studying the microstructures of samples by scanning electron microscope (SEM) and their corrosion behavior in 3.5 wt pct NaCl solutions indicated that the increase in NaAlO2 concentration (up to 10 g/L) led to an increase in uniformity and compactness, thus decreasing the size of micro-pores and increment of corrosion resistance. However, at a certain level of NaAlO2 concentration (12 g/L), large and severe sparks were created on the surface of the sample during the process, worsening the corrosion resistance and microstructure of coating.

  14. Sodium Aluminate Concentration Effects on Microstructure and Corrosion Behavior of the Plasma Electrolytic Oxidation Coatings on Pure Titanium

    Science.gov (United States)

    Molaei, Maryam; Fattah-Alhosseini, Arash; Gashti, Seyed Omid

    2018-01-01

    Sodium aluminate (NaAlO2) concentration was varied in order to understand the influence of the chemical composition of electrolyte on the spark characteristics, microstructure, and corrosion behavior of plasma electrolytic oxidation (PEO) coatings. For this purpose, PEO coatings were formed on the pure titanium substrate surface using solutions of four diverse sodium aluminate concentrations (6, 8, 10, and 12 g/L). The PEO process was carried out at constant time and voltage (180 seconds and 420 V). Studying the microstructures of samples by scanning electron microscope (SEM) and their corrosion behavior in 3.5 wt pct NaCl solutions indicated that the increase in NaAlO2 concentration (up to 10 g/L) led to an increase in uniformity and compactness, thus decreasing the size of micro-pores and increment of corrosion resistance. However, at a certain level of NaAlO2 concentration (12 g/L), large and severe sparks were created on the surface of the sample during the process, worsening the corrosion resistance and microstructure of coating.

  15. 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.

  16. 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.

  17. Tungsten oxide thin films obtained by anodisation in low electrolyte concentration

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Nadja B.D. da [Centro de Ciências Químicas, Farmacêuticas e de Alimentos, Universidade Federal de Pelotas, Campus Capão do Leão, s/n, Pelotas, RS (Brazil); Pazinato, Julia C.O. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500 Porto Alegre, RS (Brazil); Sombrio, Guilherme; Pereira, Marcelo B.; Boudinov, Henri [Instituto de Física, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500 Porto Alegre, RS (Brazil); Gündel, André; Moreira, Eduardo C. [Universidade Federal do Pampa, Travessa 45, 1650 Bagé, RS (Brazil); Garcia, Irene T.S., E-mail: irene.garcia@ufrgs.br [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500 Porto Alegre, RS (Brazil)

    2015-03-02

    Tungsten oxide nanostructured films were grown on tungsten substrates by anodisation under a fixed voltage and with sodium fluoride as electrolyte. The effect of the anion chloride and the influence of the modifying agent disodium hydrogen phosphate in the tungsten oxide films were also investigated. The structural characterisation of the films was performed by scanning electron microscopy, atomic force microscopy and Raman spectroscopy. The band gap was determined through diffuse reflectance spectroscopy. The thin films were photoluminescent and emitted in the range of 300 to 630 nm when irradiated at 266 nm. The synthesised films efficiently degraded of methyl orange dye in the presence of hydrogen peroxide and 250 nm radiation. The modifying agent was responsible for the improvement of the photocatalytic activity. Films with similar photocatalytic performance were obtained when the system sodium fluoride and disodium hydrogen phosphate were replaced by sodium chloride. The porous structure and low band gap values were responsible for the photocatalytic behaviour. - Highlights: • Tungsten oxide thin films were obtained by anodisation of tungsten in aqueous media. • The performance of the NaCl, NaF and NaF/Na{sub 2}HPO{sub 4} as electrolytes was investigated. • The relation between structure and optical behaviour has been discussed. • Films obtained with NaCl and NaF/Na{sub 2}HPO{sub 4} present similar photocatalytic activity.

  18. 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.

  19. 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

  20. 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)

  1. Effect of Porosity and Concentration Polarization on Electrolyte Diffusive Transport Parameters through Ceramic Membranes with Similar Nanopore Size

    Directory of Open Access Journals (Sweden)

    Virginia Romero

    2014-08-01

    Full Text Available Diffusive transport through nanoporous alumina membranes (NPAMs produced by the two-step anodization method, with similar pore size but different porosity, is studied by analyzing membrane potential measured with NaCl solutions at different concentrations. Donnan exclusion of co-ions at the solution/membrane interface seem to exert a certain control on the diffusive transport of ions through NPAMs with low porosity, which might be reduced by coating the membrane surface with appropriated materials, as it is the case of SiO2. Our results also show the effect of concentration polarization at the membrane surface on ionic transport numbers (or diffusion coefficients for low-porosity and high electrolyte affinity membranes, which could mask values of those characteristic electrochemical parameters.

  2. 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.

  3. 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...

  4. Effect of electrolyte concentration on performance of supercapacitor carbon electrode from fibers of oil palm empty fruit bunches

    Energy Technology Data Exchange (ETDEWEB)

    Farma, R.; Awitdrus,; Taer, E. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Departement of Physics, Faculty of Mathematics and Natural Sciences, University of Riau, 28293 Pekanbaru, Riau (Indonesia); Deraman, M., E-mail: madra@ukm.my; Talib, I. A.; Omar, R.; Ishak, M. M.; Basri, N. H.; Dolah, B. N. M. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-04-16

    Fibers of oil palm empty fruit bunches were used to produce self-adhesive carbon grains (SACG). The SACG green monoliths were carbonized in N{sub 2} environment at 800°C to produce carbon monoliths (CM) and the CM was CO{sub 2} activated at 800°C for 4 hour to produce activated carbon monolith electrodes (ACM). The physical properties of the CMs and ACMs were investigated using X-ray diffraction, field emission scanning electron microscopy and nitrogen adsorption-desorption. ACMs were used as electrode to fabricate symmetry supercapacitor cells and the cells which used H{sub 2}SO{sub 4} electrolyte at 0.5, 1.0 and 1.5 M were investigated using electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charge-discharge standard techniques. In this paper we report the physical properties of the ACM electrodes and the effect of electrolyte concentration on the electrochemical properties the ACM electrodes.

  5. 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.

  6. General electrokinetic model for concentrated suspensions in aqueous electrolyte solutions: Electrophoretic mobility and electrical conductivity in static electric fields.

    Science.gov (United States)

    Carrique, Félix; Ruiz-Reina, Emilio; Roa, Rafael; Arroyo, Francisco J; Delgado, Ángel V

    2015-10-01

    In recent years different electrokinetic cell models for concentrated colloidal suspensions in aqueous electrolyte solutions have been developed. They share some of its premises with the standard electrokinetic model for dilute colloidal suspensions, in particular, neglecting both the specific role of the so-called added counterions (i.e., those released by the particles to the solution as they get charged), and the realistic chemistry of the aqueous solution on such electrokinetic phenomena as electrophoresis and electrical conductivity. These assumptions, while having been accepted for dilute conditions (volume fractions of solids well below 1%, say), are now questioned when dealing with concentrated suspensions. In this work, we present a general electrokinetic cell model for such kind of systems, including the mentioned effects, and we also carry out a comparative study with the standard treatment (the standard solution only contains the ions that one purposely adds, without ionic contributions from particle charging or water chemistry). We also consider an intermediate model that neglects the realistic aqueous chemistry of the solution but accounts for the correct contribution of the added counterions. The results show the limits of applicability of the classical assumptions and allow one to better understand the relative role of the added counterions and ions stemming from the electrolyte in a realistic aqueous solution, on electrokinetic properties. For example, at low salt concentrations the realistic effects of the aqueous solution are the dominant ones, while as salt concentration is increased, it is this that progressively takes the control of the electrokinetic response for low to moderate volume fractions. As expected, if the solids concentration is high enough the added counterions will play the dominant role (more important the higher the particle surface charge), no matter the salt concentration if it is not too high. We hope this work can help in

  7. A Liquid Inorganic Electrolyte Showing an Unusually High Lithium Ion Transference Number: A Concentrated Solution of LiAlCl4 in Sulfur Dioxide

    Directory of Open Access Journals (Sweden)

    Martin Winter

    2013-08-01

    Full Text Available We report on studies of an inorganic electrolyte: LiAlCl4 in liquid sulfur dioxide. Concentrated solutions show a very high conductivity when compared with typical electrolytes for lithium ion batteries that are based on organic solvents. Our investigations include conductivity measurements and measurements of transference numbers via nuclear magnetic resonance (NMR and by a classical direct method, Hittorf’s method. For the use of Hittorf’s method, it is necessary to measure the concentration of the electrolyte in a selected cell compartment before and after electrochemical polarization very precisely. This task was finally performed by potentiometric titration after hydrolysis of the salt. The Haven ratio was determined to estimate the association behavior of this very concentrated electrolyte solution. The measured unusually high transference number of the lithium cation of the studied most concentrated solution, a molten solvate LiAlCl4 × 1.6SO2, makes this electrolyte a promising alternative for lithium ion cells with high power ability.

  8. 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....

  9. 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 ...

  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. INFLUENCE OF SELENIUM CONTENT AND OIL SOURCES IN FEED ON CONCENTRATION OF THYROID GLAND HORMONES AND ELECTROLYTE IN BROILER BLOOD

    Directory of Open Access Journals (Sweden)

    Zlata Kralik

    2014-12-01

    Full Text Available The research aimed to elaborate the influence of designed mixtures used in broilers fattening on the concentration of electrolytes and thyroid gland hormones in the blood.. The research was carried out on 120 male Ross 308 hybrid broilers. The fattening lasted for 42 days. During the first three weeks of fattening broilers were fed standard starter diet containing 22% crude protein and 13.90 MJ/kg ME. During the last three weeks of fattening, broilers were divided into 6 experimental groups, each fed specially prepared finisher diets (P1=6% sunflower oil+0.0 mg Se/kg of feed, P2=6% linseed oil+0.0 mg Se/kg of feed, P3=6% sunflower oil+0.3 mg Se/kg of feed, P4=6% linseed oil+0.3 mg Se/kg of feed, P5=6% sunflower oil+0.5 mg Se/kg of feed, P6=6% linseed oil+0.5 mg Se/kg of feed. Finisher diet was balanced at 18.02% crude protein and 14.40 MJ/kg ME. It was found out that the type of oil in chicken feed influenced to blood pH (P <0.001, whereas selenium level (P=0.014 in the feed, as well as the oil type and selenium level interaction (P<0.001 influenced the concentration of potassium in the blood. Oil type (P=0.037 influenced the concentration of fT3, which was lower in chickens fed mixtures with addition of linseed oil than in the chickens fed sunflower oil added mixtures. Interaction of selenium content and oil type had influence on differences in concentration of fT4 as well as on the ratio of fT3/fT4, (P<0.001, i.e. P=0.021. The research results indicated that oils supplemented to broiler diets and combined with different organic selenium concentrations affected pH, concentration of some electrolytes and thyroid gland hormones in broiler blood, however, all obtained values were within reference range for poultry.

  12. 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.

  13. 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.

  14. Effects of pored separator films at the anode and cathode sides on concentration changes of electrolyte salt in lithium ion batteries

    Science.gov (United States)

    Yamanaka, Toshiro; Nakagawa, Hiroe; Tsubouchi, Shigetaka; Domi, Yasuhiro; Doi, Takayuki; Abe, Takeshi; Ogumi, Zempachi

    2017-12-01

    The concentration change of ions in the electrolyte solution in deep narrow spaces between electrodes in batteries was studied by in situ multi-probe Raman spectroscopy. When two separator films were placed at the anode and cathode sides, the concentration change became greater, suggesting that the resistance for ion migration at the anode side increased more than that at the cathode side. Thus, there seems to be a concerted effect of the surface film at the anode [solid electrolyte interphase (SEI)] and the adjacent separator film to form an effective diffusion barrier for Li+.

  15. 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.

  16. Influence of the Electrolyte Concentration on the Smooth TiO2 Anodic Coatings on Ti-6Al-4V

    Directory of Open Access Journals (Sweden)

    María Laura Vera

    2017-03-01

    Full Text Available To obtain smooth TiO2 coatings for building a new design of Ti-6Al-4V heart valve, the anodic oxidation technique in pre-spark conditions was evaluated. TiO2 coating is necessary for its recognized biocompatibility and corrosion resistance. A required feature on surfaces in contact with blood is a low level of roughness (Ra ≤ 50 nm that does not favor the formation of blood clots. The present paper compares the coatings obtained by anodic oxidation of the Ti-6Al-4V alloy using H2SO4 at different concentrations (0.1–4 M as electrolyte and applying different voltages (from 20 to 70 V. Color and morphological analysis of coatings are performed using optical and scanning microscopy. The crystalline phases were analyzed by glancing X-ray diffraction. By varying the applied voltage, different interference colors coatings were obtained. The differences in morphologies of the coatings caused by changes in acid concentration are more evident at high voltages, limiting the oxidation conditions for the desired application. Anatase phase was detected from 70 V for 1 M H2SO4. An increase in the concentration of H2SO4 decreases the voltage at which the transformation of amorphous to crystalline coatings occurs; i.e., with 4 M H2SO4, the anatase phase appears at 60 V.

  17. Effect of electrolytes nature and concentration on the morphology and structure of MoS{sub 2} nanomaterials prepared using one-pot solvothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Akram, H., E-mail: akramhanane@yahoo.fr [Instituto de Catálisis y Petroleoquímica, CSIC, C/Marie Curie 2, Cantoblanco, 28049 Madrid (Spain); Laboratoire de Génie Chimique et Valorisation des Ressources, Faculté des Sciences et Techniques de Tanger, Université Abdelmalek Essâadi, B.P. 416 Tangier (Morocco); Mateos-Pedrero, C., E-mail: cmpedrero@yahoo.es [Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculdade de Engenharia da Universidade do Porto Rua Roberto Frias, s/n4200-465, Porto (Portugal); Gallegos-Suárez, E.; Guerrero-Ruíz, A. [Instituto de Catálisis y Petroleoquímica, CSIC, C/Marie Curie 2, Cantoblanco, 28049 Madrid (Spain); Grupo de Diseño y Aplicación de Catalizadores Heterogéneos, Unidad Asociada UNED—ICP (CSIC), Madrid (Spain); Chafik, T. [Laboratoire de Génie Chimique et Valorisation des Ressources, Faculté des Sciences et Techniques de Tanger, Université Abdelmalek Essâadi, B.P. 416 Tangier (Morocco); Rodríguez-Ramos, I. [Instituto de Catálisis y Petroleoquímica, CSIC, C/Marie Curie 2, Cantoblanco, 28049 Madrid (Spain); Grupo de Diseño y Aplicación de Catalizadores Heterogéneos, Unidad Asociada UNED—ICP (CSIC), Madrid (Spain)

    2014-07-01

    Different MoS{sub 2} nanostructures have been obtained following an innovative one-step solvothermal method by changing the concentration and type of the electrolyte while avoiding the use of surfactant. It was found that the chemical nature of the studied electrolyte ((NH{sub 4}){sub 2}CO{sub 3} or KCl) do not significantly affect the morphology and structure of the obtained MoS{sub 2} nanomaterials. Nevertheless, increasing the electrolyte concentration yields to a remarkable modification of the morphology of the resulting MoS{sub 2} from nanospheres to worm-shaped then finally to nanotubes. All the obtained nanomaterials were characterized by X-ray diffraction, (XRD), transmission electron microscopy (TEM, HRTEM), Fourier transformation infra-red spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS).

  18. 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.

  19. Electrochemical Impedance Spectroscopy of Polyvinylalcohol Based Gel Electrolyte

    National Research Council Canada - National Science Library

    Nirwan Syarif; Nurlisa Hidayanti; Edy Herianto Majlan; Monica Sari Jayanti

    2017-01-01

    Research on the effect of electrolyte ammonium salt, concentration electrolyte with plasticizer to ionic and electronic conductivity of polymer gel electrolyte has been conducted with the variations...

  20. 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.

  1. 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.

  2. 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.

  3. Effect of crude protein concentration and dietary electrolyte balance on litter quality, foot pad dermatitis, growth performance and processing yields in two medium heavy turkey hybrids

    NARCIS (Netherlands)

    Veldkamp, T.; Hocking, P.M.; Vinco, L.J.

    2017-01-01

    1. An experiment was conducted to investigate the effect of crude protein (CP) concentration and dietary electrolyte balance (DEB) on growth performance, processing yields, litter quality and foot pad dermatitis (FPD) in male turkeys from two commercial hybrids. Soya bean meal was replaced by

  4. 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

  5. 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.

  6. 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...

  7. 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

  8. 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

  9. 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.

  10. 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

  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

    2017-02-01

    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.

  12. 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.

  13. 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.

  14. 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…

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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 ...

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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....

  13. Plasma and urine electrolyte and mineral concentrations in Thoroughbred horses with recurrent exertional rhabdomyolysis after consumption of diets varying in cation-anion balance.

    Science.gov (United States)

    McKenzie, Erica C; Valberg, Stephanie J; Godden, Sandra M; Pagan, Joe D; Carlson, Gary P; MacLeay, Jennifer M; DeLaCorte, Flavio D

    2002-07-01

    To determine whether plasma, urine, and fecal electrolyte and mineral concentrations differ between clinically normal horses and Thoroughbreds with recurrent exertional rhabdomyolysis (RER) after consumption of diets varying in cation-anion balance. 5 Thoroughbred mares with RER and 6 clinically normal mixed-breed mares. Each of 3 isocaloric diets designated as low, medium, and high on the basis of dietary cation-anion balance (DCAB) values of 85, 190, and 380, respectively, were fed to horses for 14 days. During the last 72 hours, 3 horses with RER and 3 control horses had daily urine and fecal samples obtained by total 24-hour collection. Remaining horses had urine samples collected daily by single catheterization. For each diet, no differences existed between horses with RER and control horses in plasma pH, electrolyte concentrations, and creatine kinase activity or in urine pH and renal fractional excretion (FE) values. Plasma pH, strong ion difference, bicarbonate and total carbon dioxide concentrations, and base excess decreased and plasma chloride and ionized calcium concentrations increased with decreasing DCAB. Urine pH decreased with decreasing DCAB. The FE of chloride and phosphorus were greatest for horses fed the low diet. The FE values for all electrolytes exept magnesium did not differ between urine samples obtained by single catheterization and total 24-hour collection. Daily balance of calcium, phosphorus, sodium, chloride, and potassium did not differ significantly among horses fed the various diets. In clinically normal horses and in horses with RER, the DCAB strongly affects plasma and urine pH and the FE of sodium, potassium, chloride, and phosphorus.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Molecular dynamics simulations of the electrical double layer on smectite surfaces contacting concentrated mixed electrolyte (NaCl-CaCl2)

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, I.C.; Sposito, G.

    2011-04-01

    We report new molecular dynamics results elucidating the structure of the electrical double layer (EDL) on smectite surfaces contacting mixed NaCl-CaCl{sup 2} electrolyte solutions in the range of concentrations relevant to pore waters in geologic repositories for CO{sub 2} or high-level radioactive waste (0.34-1.83 mol{sub c} dm{sup -3}). Our results confirm the existence of three distinct ion adsorption planes (0-, {beta}-, and d-planes), often assumed in EDL models, but with two important qualifications: (1) the location of the {beta}- and d-planes are independent of ionic strength or ion type and (2) 'indifferent electrolyte' ions can occupy all three planes. Charge inversion occurred in the diffuse ion swarm because of the affinity of the clay surface for CaCl{sup +} ion pairs. Therefore, at concentrations 0.34 mol{sub c} dm{sup -3}, properties arising from long-range electrostatics at interfaces (electrophoresis, electro-osmosis, co-ion exclusion, colloidal aggregation) will not be correctly predicted by most EDL models. Co-ion exclusion, typically neglected by surface speciation models, balanced a large part of the clay mineral structural charge in the more concentrated solutions. Water molecules and ions diffused relatively rapidly even in the first statistical water monolayer, contradicting reports of rigid 'ice-like' structures for water on clay mineral surfaces.

  19. 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.

  20. 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…

  1. 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...

  2. 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.

  3. Measurement of extremely (2) H-enriched water samples by laser spectrometry: application to batch electrolytic concentration of environmental tritium samples.

    Science.gov (United States)

    Wassenaar, L I; Kumar, B; Douence, C; Belachew, D L; Aggarwal, P K

    2016-02-15

    Natural water samples artificially or experimentally enriched in deuterium ((2) H) at concentrations up to 10,000 ppm are required for various medical, environmental and hydrological tracer applications, but are difficult to measure using conventional stable isotope ratio mass spectrometry. Here we demonstrate that off-axis integrated cavity output (OA-ICOS) laser spectrometry, along with (2) H-enriched laboratory calibration standards and appropriate analysis templates, allows for low-cost, fast, and accurate determinations of water samples having δ(2) HVSMOW-SLAP values up to at least 57,000 ‰ (~9000 ppm) at a processing rate of 60 samples per day. As one practical application, extremely (2) H-enriched samples were measured by laser spectrometry and compared to the traditional (3) H Spike-Proxy method in order to determine tritium enrichment factors in the batch electrolysis of environmental waters. Highly (2) H-enriched samples were taken from different sets of electrolytically concentrated standards and low-level (enriched waters by laser spectrometry will facilitate the use of deuterium as a tracer in numerous environmental and other applications. For low-level tritium operations, this new analytical ability facilitated a 10-20 % increase in sample productivity through the elimination of spike standards and gravimetrics, and provides immediate feedback on electrolytic enrichment cell performance. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Understanding corrosion behavior of Mg–Zn–Ca alloys from subcutaneous mouse model: Effect of Zn element concentration and plasma electrolytic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Yongseok [Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB), North Carolina A and T State University, Greensboro, NC 27411 (United States); Tan, Zongqing [Department of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, OH 45221 (United States); Jurey, Chris [Luke Engineering, Wadsworth, OH 44282 (United States); Xu, Zhigang [Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB), North Carolina A and T State University, Greensboro, NC 27411 (United States); Dong, Zhongyun [Department of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, OH 45221 (United States); Collins, Boyce [Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB), North Carolina A and T State University, Greensboro, NC 27411 (United States); Yun, Yeoheung, E-mail: yyun@ncat.edu [Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB), North Carolina A and T State University, Greensboro, NC 27411 (United States); Sankar, Jagannathan [Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB), North Carolina A and T State University, Greensboro, NC 27411 (United States)

    2015-03-01

    Mg–Zn–Ca alloys are considered as suitable biodegradable metallic implants because of their biocompatibility and proper physical properties. In this study, we investigated the effect of Zn concentration of Mg–xZn–0.3Ca (x = 1, 3 and 5 wt.%) alloys and surface modification by plasma electrolytic oxidation (PEO) on corrosion behavior in in vivo environment in terms of microstructure, corrosion rate, types of corrosion, and corrosion product formation. Microstructure analysis of alloys and morphological characterization of corrosion products were conducted using x-ray computed tomography (micro-CT) and scanning electron microscopy (SEM). Elemental composition and crystal structure of corrosion products were determined using x-ray diffraction (XRD) and electron dispersive x-ray spectroscopy (EDX). The results show that 1) as-cast Mg–xZn–0.3Ca alloys are composed of Mg matrix and a secondary phase of Ca{sub 2}Mg{sub 6}Zn{sub 3} formed along grain boundaries, 2) the corrosion rate of Mg–xZn–0.3Ca alloys increases with increasing concentration of Zn in the alloy, 3) corrosion rates of alloys treated by PEO sample are decreased in in vivo environment, and 4) the corrosion products of these alloys after in vivo tests are identified as brucite (Mg(OH){sub 2}), hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}), and magnesite (MgCO{sub 3}·3H{sub 2}O). - Highlights: • Effects of PEO and Zn concentration in Mg–xZn–0.3Ca alloys on biodegradation • Corrosion rate of Mg–xZn–0.3Ca alloys increases with increasing Zn concentration. • Plasma electrolytic oxidation retards the biodegradation of Mg–xZn–0.3Ca alloys.

  5. 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

  6. 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.

  7. Variability of measurements of sweat sodium using the regional absorbent-patch method.

    Science.gov (United States)

    Dziedzic, Christine E; Ross, Megan L; Slater, Gary J; Burke, Louise M

    2014-09-01

    There is interest in including recommendations for the replacement of the sodium lost in sweat in individualized hydration plans for athletes. Although the regional absorbent-patch method provides a practical approach to measuring sweat sodium losses in field conditions, there is a need to understand the variability of estimates associated with this technique. Sweat samples were collected from the forearms, chest, scapula, and thigh of 12 cyclists during 2 standardized cycling time trials in the heat and 2 in temperate conditions. Single measure analysis of sodium concentration was conducted immediately by ion-selective electrodes (ISE). A subset of 30 samples was frozen for reanalysis of sodium concentration using ISE, flame photometry (FP), and conductivity (SC). Sweat samples collected in hot conditions produced higher sweat sodium concentrations than those from the temperate environment (P = .0032). A significant difference (P = .0048) in estimates of sweat sodium concentration was evident when calculated from the forearm average (mean ± 95% CL; 64 ± 12 mmol/L) compared with using a 4-site equation (70 ± 12 mmol/L). There was a high correlation between the values produced using different analytical techniques (r2 = .95), but mean values were different between treatments (frozen FP, frozen SC > immediate ISE > frozen ISE; P sweat sodium concentration estimates differed depending on the number of sites included in the calculation. Environmental testing conditions should be considered in the interpretation of results. The impact of sample freezing and subsequent analytical technique was small but statistically significant. Nevertheless, when undertaken using a standardized protocol, the regional absorbent-patch method appears to be a relatively robust field test.

  8. Diagnosis of cystic fibrosis with chloride meter (Sherwood M926S chloride analyzer®) and sweat test analysis system (CFΔ collection system®) compared to the Gibson Cooke method.

    Science.gov (United States)

    Emiralioğlu, Nagehan; Özçelik, Uğur; Yalçın, Ebru; Doğru, Deniz; Kiper, Nural

    2016-01-01

    Sweat test with Gibson Cooke (GC) method is the diagnostic gold standard for cystic fibrosis (CF). Recently, alternative methods have been introduced to simplify both the collection and analysis of sweat samples. Our aim was to compare sweat chloride values obtained by GC method with other sweat test methods in patients diagnosed with CF and whose CF diagnosis had been ruled out. We wanted to determine if the other sweat test methods could reliably identify patients with CF and differentiate them from healthy subjects. Chloride concentration was measured with GC method, chloride meter and sweat test analysis system; also conductivity was determined with sweat test analysis system. Forty eight patients with CF and 82 patients without CF underwent the sweat test, showing median sweat chloride values 98.9 mEq/L with GC method, 101 mmol/L with chloride meter, 87.8 mmol/L with sweat test analysis system. In non-CF group, median sweat chloride values were 16.8 mEq/L with GC method, 10.5 mmol/L with chloride meter, and 15.6 mmol/L with sweat test analysis system. Median conductivity value was 107.3 mmol/L in CF group and 32.1 mmol/L in non CF group. There was a strong positive correlation between GC method and the other sweat test methods with a statistical significance (r=0.85) in all subjects. Sweat chloride concentration and conductivity by other sweat test methods highly correlate with the GC method. We think that the other sweat test equipments can be used as reliably as the classic GC method to diagnose or exclude CF.

  9. 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

  10. 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.

  11. Experimental investigation on the formation mechanism of the TiFe alloy by the molten-salt electrolytic titanium concentrate

    Directory of Open Access Journals (Sweden)

    Shi R.

    2011-01-01

    Full Text Available The ferrotitanium alloy was prepared in the molten CaCl2 system, in which resolidified ilmenite and the graphite crucible were used as cathode and anode. In this study, the electrolytic voltage was fixed at 3.1V, and three different temperatures were applied: 850oC, 875oC and 900ºC. Finally, the product was examined by SEM and XRD to determine the phase transformation after the electrolysis. The results show that the ilmenite was firstly reduced to Fe, and finally the TiFe alloy was formed. The intermediate products include CaTiO3, TiO2, Ti2O3, TiO, Fe, TiFe2, and Ti. Different product and structure can be obtained by changing temperature. According to thermodynamic calculation, the principal electroreduction products are Ti and TiFe2 and then Ti and TiFe2 are formed by interdiffusion which is governed by temperature.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. Effect of ’Streptococcus Pneumoniae’ Infection in Rats on Hepatic Water Content, Electrolyte Concentration, and Chemical Composition

    Science.gov (United States)

    1981-01-01

    these constituents decreases in the extracted by the method of Folch et al. "! Carbohydrate was assayed by the method of Dubois et al," using sucrose as...bioelectrical balance and osmosis . The Protein (g) 1.26t ±0.03 1.60 ± 0.08 ɘ.001 significant increases in total liver Na + and Cl- concentration (i.6

  4. 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.

  5. 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.

  6. 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.

  7. Hydrochromic Approaches to Mapping Human Sweat Pores.

    Science.gov (United States)

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

    2016-06-21

    Hydrochromic materials, which undergo changes in their light absorption and/or emission properties in response to water, have been extensively investigated as humidity sensors. Recent advances in the design of these materials have led to novel applications, including monitoring the water content of organic solvents, water-jet-based rewritable printing on paper, and hydrochromic mapping of human sweat pores. Our interest in this area has focused on the design of hydrochromic materials for human sweat pore mapping. We recognized that materials appropriate for this purpose must have balanced sensitivities to water. Specifically, while they should not undergo light absorption and/or emission transitions under ambient moisture conditions, the materials must have sufficiently high hydrochromic sensitivities that they display responses to water secreted from human sweat pores. In this Account, we describe investigations that we have carried out to develop hydrochromic substances that are suitable for human sweat pore mapping. Polydiacetylenes (PDAs) have been extensively investigated as sensor matrices because of their stimulus-responsive color change property. We found that incorporation of headgroups composed of hygroscopic ions such as cesium or rubidium and carboxylate counterions enables PDAs to undergo a blue-to-red colorimetric transition as well as a fluorescence turn-on response to water. Very intriguingly, the small quantities of water secreted from human sweat pores were found to be sufficient to trigger fluorescence turn-on responses of the hydrochromic PDAs, allowing precise mapping of human sweat pores. Since the hygroscopic ion-containing PDAs developed in the initial stage display a colorimetric transition under ambient conditions that exist during humid summer periods, a new system was designed. A PDA containing an imidazolium ion was found to be stable under all ambient conditions and showed temperature-dependent hydrochromism corresponding to a

  8. High concentration of H2 and O2 nanobubbles in water electrolytes and their collective optical effect

    Science.gov (United States)

    Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; Svetovoy, V. B.

    2017-09-01

    Water electrolysis with a fast change of the polarity pumps in the liquid a huge amount of hydrogen and oxygen gases. In contrast with the DC electrolysis the gases do not form visible bubbles but change significantly the refractive index of the liquid nearby the electrodes from n = 1.35 to the values smaller than 1.19. The decrease of n is registered as distortion of the images of the electrodes. We argue that all the gas is collected in H2 and O2 nanobubbles with a size smaller than 200 nm. The concentration of nanobubbles with a size of 100 nm is estimated as 1021 m-3. Due to a significant contribution from the Laplace pressure the effective supersaturation reaches 500 for hydrogen and 150 for oxygen.

  9. 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.

  10. 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.

  11. '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...

  12. 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

  13. 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.

  14. Role of Sweat in Accumulation of Orally Administered Griseofulvin in Skin

    Science.gov (United States)

    Shah, Vinod P.; Epstein, William L.; Riegelman, Sidney

    1974-01-01

    Griseofulvin, an orally effective antimicrobial agent, appears in the stratum corneum within 4-8 h after oral administration. Griseofulvin distribution was found to be highest in the outermost layers of the stratum corneum (level I, 20.8±1.5 ng/mg) and lowest inside (level II, 10.0±1.5; level III, 7.5±2.2 ng/mg). In order to study the precise mechanism of griseofulvin transfer to stratum corneum, the role of sweat in the accumulation of griseofulvin was considered. Heat-induced total body sweating decreased the mean stratum corneum concentration of griseofulvin by 55%, and 200-300 ng of griseofulvin accumulated per ml of sweat. A silicone hydrophobic resin was used to differentiate between “wash-off” and carrier properties of sweat for griseofulvin. Prevention of transepidermal water and sweat loss by (a) topical application of formaldehyde-releasing cream to one palm, (b) occlusion by a 2 × 2-cm patch on one arm, and (c) wearing a rubber glove for 24 h, showed a lower griseofulvin concentration when compared to control areas in the same subjects. The results of the gloved hand experiment show that a complete equilibrium is established at all three levels of stratum corneum, thereby removing the reversed gradient. These results support the hypothesis that a “wick effect” is responsible for the observed reversed drug gradient within the stratum corneum. The results of the experiments suggest that sweat and transepidermal fluid loss play an important role in griseofulvin transfer in stratum corneum. PMID:4830229

  15. 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…

  16. 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).

  17. 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

  18. 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.

  19. 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

    -exercise and sweat was collected using sweat patches. The average time to complete the competition was 85.0 ± 6.57 min. The percentage of dehydration was 3.0 ± 0.92%. The replacement of fluid losses was 31 ± 18.7%. The sweat rate was 1.86 ± 0.56 L•h-1. Sweat Na+, K+, and Cl-concentrations were 71 ± 26.05 mmol•L-1, 5.43 ±1.98 mmol•L-1 and 58.93 ± 25.99 mmol•L-1, respectively. The total sweat loss of Na+, K+ and Cl- was 132.11± 62.82 mmol, 10.09 ± 5.01 mmol and 109.75 ± 58.49 mmol, respectively. In conclusion, the athletes did not drink enough liquid to replace their volume of fluid loss. Furthermore, the participants presented high sweat rate accompanied by losses of Na+, K+ and Cl-. However, serum electrolyte concentrations were not changed.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Electrolyte chemistry control in electrodialysis processing

    Science.gov (United States)

    Hayes, Thomas D.; Severin, Blaine F.

    2017-12-26

    Methods for controlling electrolyte chemistry in electrodialysis units having an anode and a cathode each in an electrolyte of a selected concentration and a membrane stack disposed therebetween. The membrane stack includes pairs of cationic selective and anionic membranes to segregate increasingly dilute salts streams from concentrated salts stream. Electrolyte chemistry control is via use of at least one of following techniques: a single calcium exclusionary cationic selective membrane at a cathode cell boundary, an exclusionary membrane configured as a hydraulically isolated scavenger cell, a multivalent scavenger co-electrolyte and combinations thereof.

  5. 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.

  6. 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....

  7. Biomonitoring and Elimination of Perfluorinated Compounds and Polychlorinated Biphenyls through Perspiration: Blood, Urine, and Sweat Study

    Science.gov (United States)

    Genuis, Stephen J.; Beesoon, Sanjay; Birkholz, Detlef

    2013-01-01

    Perfluorinated compounds (PFCs) are man-made organofluorine chemicals manufactured and marketed for their stain-resistant properties. Polychlorinated biphenyls (PCBs) are anthropogenic organochlorine compounds previously used in various industrial and chemical applications prior to being banned in the Western world in the 1970s. Both PFCs and PCBs are persistent contaminants within the human organism and both have been linked to adverse health sequelae. Data is lacking on effective means to facilitate clearance of PFCs and PCBs from the body. Methods. Blood, urine, and sweat were collected from 20 individuals (10 healthy participants and 10 participants with assorted health problems) and analyzed for PFCs and PCBs using high performance liquid chromatography tandem mass spectrometry. Results. Some individual PCB congeners, but not all, were released into sweat at varying concentrations. None of the PFCs found in serum testing appeared to be excreted efficiently into perspiration. Conclusions. Induced perspiration may have some role in facilitating elimination of selected PCBs. Sweat analysis may be helpful in establishing the existence of some accrued PCBs in the human body. Sweating does not appear to facilitate clearance of accrued PFHxS (perfluorohexane sulfonate), PFOS (perfluorooctane sulfonate), or PFOA (perfluorooctanoic acid), the most common PFCs found in the human body. PMID:24083032

  8. The Italian pilot external quality assessment program for cystic fibrosis sweat test.

    Science.gov (United States)

    Salvatore, Marco; Floridia, Giovanna; Amato, Annalisa; Censi, Federica; Carta, Claudio; de Stefano, Maria Chiara; Ferrari, Gianluca; Tosto, Fabrizio; Capoluongo, Ettore; Caruso, Ubaldo; Castaldo, Giuseppe; Cirilli, Natalia; Corbetta, Carlo; Padoan, Rita; Raia, Valeria; Taruscio, Domenica

    2016-05-01

    Sweat chloride test is the gold standard test for cystic fibrosis (CF) diagnosis. In 2014 the Istituto Superiore di Sanità established the Italian pilot external quality assessment program for CF sweat test (IEQA-ST). Ten laboratories, included among the 33 Italian CF Referral Centers, were selected and enrolled on the basis of their attitude to perform sweat test (ST) analysis by using methods recommended by the Italian Guidelines. They received three different sweat-like samples (normal, borderline and pathologic chloride concentration), with mock clinical indications, for analysis according to routine procedures. Assessment, performed by a panel of experts, covered analytical performance, interpretation and reporting of results; categories of "poor" and "satisfactory" performance were not defined. All data were managed through a web utility. The program identified important areas of interest and, in some case, of concern. It is important to underline that results are referred to a small proportion, i.e. about 30%, of Italian laboratories performing CF ST in the context of the Referral Centers. Data collected highlight the importance of participation in EQA programs as it may improve laboratory/clinical performance; our study represents a model for the setting up of a large-scale EQA scheme for ST. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  9. [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.

  10. 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.

  11. 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.

  12. 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...

  13. [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.

  14. 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

  15. Relationship between some serum electrolytes and ...

    African Journals Online (AJOL)

    The effect of Trypanosoma brucei infection on changes in concentration of some serum electrolytes and the consequence of these changes on electrocardiographic (ECG) indices were investigated in dogs. The nature of association between each of the electrolytes and the various ECG indices were studied at different days ...

  16. 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.

  17. Electrolytes for magnesium electrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Burrell, Anthony K.; Sa, Niya; Proffit, Danielle Lee; Lipson, Albert; Liao, Chen; Vaughey, John T.; Ingram, Brian J.

    2017-07-04

    An electrochemical cell includes a high voltage cathode configured to operate at 1.5 volts or greater; an anode including Mg.sup.0; and an electrolyte including an ether solvent and a magnesium salt; wherein: a concentration of the magnesium salt in the ether is 1 M or greater.

  18. Formaldehyde solutions in simulated sweat increase human melanoma but not normal human keratinocyte cells proliferation.

    Science.gov (United States)

    Rizzi, M; Cravello, B; Tonello, S; Renò, F

    2016-12-01

    Our skin is in close contact with clothes most of the time thus risking potentially noxious chemicals contact. One of the potentially harmful manufacturing by-products that can be released by textiles when sweating is formaldehyde, used as an anti-crease treatment. As it is known to be carcinogenic to humans and a potent skin sensitizer, the aim of this study was to investigate its effects on both normal human keratinocytes (HaCaT cells) and on a highly invasive malignant melanoma cell line (SK-MEL-28) in order to contribute to the definition of safety cut-off to be applied to the production processes. Formaldehyde concentrations below the commonly accepted limits (10-50μM) were obtained by diluting formaldehyde in simulated sweat (UNI EN ISO 105-E04). The effects on cell proliferation were evaluated by cell counting, while ERK pathway activation was evaluated by western blot. Low concentrations of formaldehyde (10μM) in both acidic and alkaline simulated sweat were able to increase malignant melanoma cell proliferation, while not affecting normal keratinocytes. Melanoma proliferation increase was greater in acidic (pH=5.5) than in alkaline (pH=8) conditions. Moreover, formaldehyde stimulation was able to induce ERK pathway activation. The data obtained suggest the need for an even increasing attention to the potentially harmful effects of textile manufacturing by-products. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. 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.

  20. 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 ...

  1. 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

  2. \\'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 ...

  3. 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....

  4. 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. ...

  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. 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

  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. 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.

  12. 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.

  13. 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.

  14. Evaluating the effect of administrating hypertonic and isotonic saline solutions on clinical improvement, serum electrolyte concentrations and renal function of calves affected by diarrhea

    Directory of Open Access Journals (Sweden)

    A Hasanpour

    2009-11-01

    This study was conducted on 40 calves under the age of one mouth with 30 calves affected by diarrhea allocated to 3 treatment groups of 10 calves each and the control group consisting of 10 calves. The control group received neither treatment nor any injections. In the first treatment group, only antibiotics were administered without any fluid therapy. In the second treatment group, apart from antibiotic therapy of diarrhea, hypertonic saline solution (7.5% was administered at a dose of 5 ml/kg as slow intravenous infusion alongside oral ORS solution whereas in the third treatment group isotonic saline solution (0.9% was given intravenously according to the formula (Body weight × %Dehydration alongside oral ORS solution. In all groups, clinical examination and blood sampling was undertaken at times 0, 1, 2, 8 and 24 hours following treatment. At time 0, the diarrhea had resulted in clinical and laboratory signs such as a fever, the dehydration, tachycardia, oligopnea, increased packed sell volume, hypernatremia, hyperchloremia, hyperkalemia, hyperphosphatemia, hypercalcemia, increased serum creatinine and BUN values. Following treatment, fever subsided and the dehydration was corrected and this correction occurred faster in calves which had received hypertonic saline solution. Correction of sodium, potassium, chloride, phosphorus and calsium imbalance occurred faster in patients which were treated by hypertonic solution. Fluid therapy with saline solutions prevented the increase in serum creatinine and BUN values. In conclusion, the administration of hypertonic saline solutions leads to much faster and more reliable clinical improvement and electrolyte imbalance correction in calves affected by diarrhea.

  15. 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.

  16. 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.

  17. 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.

  18. Magnesium removal in the electrolytic zinc industry

    OpenAIRE

    Booster, J.L.

    2003-01-01

    Electrolytic zinc plants need to take measures to control the magnesium content in their process liquors, because the natural magnesium bleed does not balance the input from concentrates. Presently used methods are environmentally unfriendly (due to the production of large amounts of waste gypsum) or expensive. Therefore, an alternative process route is explored in which magnesium is removed from zinc electrolyte by selective precipitation of magnesium fluoride (sellaite). As standard applica...

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Clinical evaluation of the Nanoduct sweat test system in the diagnosis of cystic fibrosis after newborn screening.

    Science.gov (United States)

    Vernooij-van Langen, Annette; Dompeling, Edward; Yntema, Jan-Bart; Arets, Bert; Tiddens, Harm; Loeber, Gerard; Dankert-Roelse, Jeannette

    2015-08-01

    After a positive newborn screening test for cystic fibrosis (CF), a sweat test is performed to confirm the diagnosis. The success rate of the generally acknowledged methods (Macroduct/Gibson and Cooke) in newborns varies between 73 and 99%. The Nanoduct sweat test system is easier to perform and less sweat is needed. The main aim of this study was to measure the success rate of the Nanoduct compared to current approved sweat test methods in a newborn population. After informed consent of the parents, newborns with a positive screening test for CF were included. The Macroduct or Gibson and Cooke and Nanoduct were performed in all infants, during the same appointment. The chloride concentration was determined by standard coulorimetry; conductivity was measured directly and converted to a NaCl molarity. One hundred eight newborns were included: 17 with CF, 7 with cystic fibrosis transmembrane regulator (CFTR)-related metabolic syndrome (CRMS), and 84 healthy children. The success rate of the Nanoduct was 93% and for the Macroduct/Gibson and Cooke 79% (McNemar, p = 0.002). The Nanoduct detected the same CF patients as the Macroduct/Gibson and Cooke; one CF patient had an equivocal result for both tests, and no patients were missed. The area under the receiver operating characteristic curve for detection of CF with the Nanoduct was 0.999, with ideal cutoff levels of 91 and 66 mmol/l, comparable to former studies. The success rate of the Nanoduct to collect sufficient sweat in infants was higher compared to the Macroduct and Gibson and Cooke.

  4. Mycostatic effect of recombinant dermcidin against Trichophyton rubrum and reduced dermcidin expression in the sweat of tinea pedis patients.

    Science.gov (United States)

    Arai, Satoru; Yoshino, Takashi; Fujimura, Takao; Maruyama, Sachie; Nakano, Toshiaki; Mukuno, Akira; Sato, Naoya; Katsuoka, Kensei

    2015-01-01

    Trichophytosis, a common dermatophytosis, affects nearly 20-25% of the world's population. However, little is known about mechanisms for preventing colonization of Trichophyton on the skin. Dermcidin, an antimicrobial peptide that provides innate immunity to the skin and is constitutively secreted even in the absence of inflammatory stimulation, was studied to elucidate its antimycotic activity against Trichophyton. Recombinant dermcidin was determined to have antimycotic activity against Trichophyton rubrum, as evaluated by colony-forming unit (CFU) assays. The killing rate of dermcidin was 40.5% and 93.4% at 50 μg/mL (the average dermcidin concentration in healthy subjects) and 270 μg/mL, respectively. An effect of dermcidin treatment was found to be a reduction of the metabolic activity of Trichophyton as determined by nicotinamide adenine dinucleotide assay. Further, dermcidin concentrations in sweat of tinea pedis patients were found to be lower than those of healthy subjects. These findings suggest a mycostatic role for dermcidin, at normal sweat concentrations. Accordingly, we suspect that dermcidin, at normal sweat concentrations, inhibits growth of Trichophyton, where Trichophyton is subsequently eliminated in conjunction with epidermis turnover. Dermcidin, therefore, appears to play a role in the skin protection mechanism that prevents colonization of tinea pedis. © 2014 Japanese Dermatological Association.

  5. 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.

  6. 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.

  7. [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.

  8. 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.

  9. 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

  10. 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 ...

  11. Latherin: a surfactant protein of horse sweat and saliva.

    Directory of Open Access Journals (Sweden)

    Rhona E McDonald

    2009-05-01

    Full Text Available Horses are unusual in producing protein-rich sweat for thermoregulation, a major component of which is latherin, a highly surface-active, non-glycosylated protein. The amino acid sequence of latherin, determined from cDNA analysis, is highly conserved across four geographically dispersed equid species (horse, zebra, onager, ass, and is similar to a family of proteins only found previously in the oral cavity and associated tissues of mammals. Latherin produces a significant reduction in water surface tension at low concentrations (< or = 1 mg ml(-1, and therefore probably acts as a wetting agent to facilitate evaporative cooling through a waterproofed pelt. Neutron reflection experiments indicate that this detergent-like activity is associated with the formation of a dense protein layer, about 10 A thick, at the air-water interface. However, biophysical characterization (circular dichroism, differential scanning calorimetry in solution shows that latherin behaves like a typical globular protein, although with unusual intrinsic fluorescence characteristics, suggesting that significant conformational change or unfolding of the protein is required for assembly of the air-water interfacial layer. RT-PCR screening revealed latherin transcripts in horse skin and salivary gland but in no other tissues. Recombinant latherin produced in bacteria was also found to be the target of IgE antibody from horse-allergic subjects. Equids therefore may have adapted an oral/salivary mucosal protein for two purposes peculiar to their lifestyle, namely their need for rapid and efficient heat dissipation and their specialisation for masticating and processing large quantities of dry food material.

  12. [Cardiac arrhythmias caused by electrolyte imbalance].

    Science.gov (United States)

    Nishimura, M; Nakayama, K; Ishikawa, Y

    1996-08-01

    Cardiac arrhythmias are known to be caused by many factors. Among them, electrolyte imbalance is the most important because of electrical activity of the heart is composed of transmembrane fluxes of Na+, Ca2+ and K+. In this review article, we describe the effects of high or low concentrations of these electrolytes on the active and passive electrical properties of the membrane in the cardiac tissues, and the mechanisms by which these electrolytes cause abnormal impulse formation and conduction in the heart. Antagonism and synergism of electrolytes and pathological conditions such as digitalis intoxication and ischemia are discussed with respect to not only cardiac electrophysiology but also cellular metabolism. A pathophysiological role of Mg2+ to maintain normal excitation and conduction of the heart is also pointed out.

  13. Improved Electrolytic Hydrogen Peroxide Generator

    Science.gov (United States)

    James, Patrick I.

    2005-01-01

    An improved apparatus for the electrolytic generation of hydrogen peroxide dissolved in water has been developed. The apparatus is a prototype of H2O2 generators for the safe and effective sterilization of water, sterilization of equipment in contact with water, and other applications in which there is need for hydrogen peroxide at low concentration as an oxidant. Potential applications for electrolytic H2O2 generators include purification of water for drinking and for use in industrial processes, sanitation for hospitals and biotechnological industries, inhibition and removal of biofouling in heat exchangers, cooling towers, filtration units, and the treatment of wastewater by use of advanced oxidation processes that are promoted by H2O2.

  14. 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...

  15. 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

  16. 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…

  17. 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.

  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. 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...

  20. Reduced expression of dermcidin, a peptide active against propionibacterium acnes, in sweat of patients with acne vulgaris.

    Science.gov (United States)

    Nakano, Toshiaki; Yoshino, Takashi; Fujimura, Takao; Arai, Satoru; Mukuno, Akira; Sato, Naoya; Katsuoka, Kensei

    2015-09-01

    Dermcidin (DCD), an antimicrobial peptide with a broad spectrum of activity against bacteria such as Propionibacterum acnes, is expressed constitutively in sweat in the absence of stimulation due to injury or inflammation. The aim of this study was to determine the relationship between DCD expression and acne vulgaris associated with P. acnes. The antimicrobial activity of recombinant full-length DCD (50 μg/ml) was 97% against Escherichia coli and 100% against Staphylococcus aureus. Antimicrobial activity against P. acnes ranged from 68% at 50 μg/ml DCD to 83% at 270 μg/ml DCD. DCD concentration in sweat from patients with acne vulgaris (median 9.8 μg/ml, range 6.9-95.3 μg/ml) was significantly lower than in healthy subjects (median 136.7 μg/ml, range 45.4-201.6 μg/ml) (p = 0.001). DCD demonstrated concentration-dependent, but partial, microbicidal activity against P. acnes. These results suggest that reduced DCD concentration in sweat in patients with inflammatory acne may permit proliferation of P. acnes in pilosebaceous units, resulting in progression of inflammatory acne.

  1. 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 ...

  2. A Comparative Study of Electrolyte Flow and Slime Particle Transport in a Newly Designed Copper Electrolytic Cell and a Laboratory-Scale Conventional Electrolytic Cell

    Science.gov (United States)

    Zeng, Weizhi; Wang, Shijie; Free, Michael L.

    2017-10-01

    An innovative copper electrolytic cell was designed with its inlet at the cell top and its outlet near the cell bottom, in opposite to conventional electrolytic cells. It was modeled in COMSOL Multiphysics to simulate copper electrorefining process. Unlike conventional electrorefining cells, downward electrolyte flows are more dominant in the fluid flow field in this cell, which leads to faster settlement of slime particles and less contamination to the cathode. Copper concentration profiles, electrolyte flow velocity field, slime particle movements, and slime particle distributions were obtained as simulation results, which were compared with those in a laboratory-scale conventional electrolytic cell. Advantages of the newly designed electrolytic cell were found: copper ions are distributed more uniformly in the cell with a thinner diffusion layer near the cathode; stronger convection exists in the inter-electrode domain with dominant downward flows; and slime particles have larger possibilities to settle down and are less likely to reach the cathode.

  3. 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...

  4. Effect of the polyacrylamide concentration on the quality of the copper deposit obtained by electrolytic refining; Efecto de la concentracion de poliacrilamida sobre la calidad del deposito de cobre obtenido por refino electrolitico

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, J.; Ipinza, J.; Camus, J.; Vargas, A.; Saavedra, R.

    2013-07-01

    The effect of the additive non ionic polyacrylamide (PAM), was studied at the laboratory level, as refining crystalline grain in the copper electrorefining. Experiments were performed 24 h of electrolysis, using an electrolyte of copper sulphate acid, with 0.5 to 10 mg{sup -}1 polyacrylamide at 55 degree centigrade and a current density of 260 Am{sup -}2. The effectiveness of these organic additives in copper electrorefining was determined by directly measuring the surface roughness of the copper deposit and contrasted with the results of other instrumental techniques (SEM and metallographic analysis). The results of the analysis SEM, metallographic analysis and measurement of the surface roughness of the copper deposit, show that to concentrations as low as 0.5 mg{sup -}1 of this additive is manifested its property of tuner of grain. However, in the range of 7 to 10 mg{sup -}1 of polyacrylamide, it reaches an optimum size of grain for the deposit of copper in the cathodes. (Author)

  5. 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…

  6. 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 ...

  7. 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.

  8. 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.

  9. Thermodynamic modeling of poorly complexing metals in concentrated electrolyte solutions: an X-ray absorption and UV-Vis spectroscopic study of Ni(II) in the NiCl2-MgCl2-H2O system.

    Science.gov (United States)

    Zhang, Ning; Brugger, Joël; Etschmann, Barbara; Ngothai, Yung; Zeng, Dewen

    2015-01-01

    Knowledge of the structure and speciation of aqueous Ni(II)-chloride complexes is important for understanding Ni behavior in hydrometallurgical extraction. The effect of concentration on the first-shell structure of Ni(II) in aqueous NiCl2 and NiCl2-MgCl2 solutions was investigated by Ni K edge X-ray absorption (XAS) and UV-Vis spectroscopy at ambient conditions. Both techniques show that no large structural change (e.g., transition from octahedral to tetrahedral-like configuration) occurs. Both methods confirm that the Ni(II) aqua ion (with six coordinated water molecules at RNi-O = 2.07(2) Å) is the dominant species over the whole NiCl2 concentration range. However, XANES, EXAFS and UV-Vis data show subtle changes at high salinity (> 2 mol∙kg(-1) NiCl2), which are consistent with the formation of small amounts of the NiCl+ complex (up to 0.44(23) Cl at a Ni-Cl distance of 2.35(2) Å in 5.05 mol∙kg(-1) NiCl2) in the pure NiCl2 solutions. At high Cl:Ni ratio in the NiCl2-MgCl2-H2O solutions, small amounts of [NiCl2]0 are also present. We developed a speciation-based mixed-solvent electrolyte (MSE) model to describe activity-composition relationships in NiCl2-MgCl2-H2O solutions, and at the same time predict Ni(II) speciation that is consistent with our XAS and UV-Vis data and with existing literature data up to the solubility limit, resolving a long-standing uncertainty about the role of chloride complexing in this system.

  10. Thermodynamic Modeling of Poorly Complexing Metals in Concentrated Electrolyte Solutions: An X-Ray Absorption and UV-Vis Spectroscopic Study of Ni(II) in the NiCl2-MgCl2-H2O System

    Science.gov (United States)

    Zhang, Ning; Brugger, Joël; Etschmann, Barbara; Ngothai, Yung; Zeng, Dewen

    2015-01-01

    Knowledge of the structure and speciation of aqueous Ni(II)-chloride complexes is important for understanding Ni behavior in hydrometallurgical extraction. The effect of concentration on the first-shell structure of Ni(II) in aqueous NiCl2 and NiCl2-MgCl2 solutions was investigated by Ni K edge X-ray absorption (XAS) and UV-Vis spectroscopy at ambient conditions. Both techniques show that no large structural change (e.g., transition from octahedral to tetrahedral-like configuration) occurs. Both methods confirm that the Ni(II) aqua ion (with six coordinated water molecules at RNi-O = 2.07(2) Å) is the dominant species over the whole NiCl2 concentration range. However, XANES, EXAFS and UV-Vis data show subtle changes at high salinity (> 2 mol∙kg-1 NiCl2), which are consistent with the formation of small amounts of the NiCl+ complex (up to 0.44(23) Cl at a Ni-Cl distance of 2.35(2) Å in 5.05 mol∙kg-1 NiCl2) in the pure NiCl2 solutions. At high Cl:Ni ratio in the NiCl2-MgCl2-H2O solutions, small amounts of [NiCl2]0 are also present. We developed a speciation-based mixed-solvent electrolyte (MSE) model to describe activity-composition relationships in NiCl2-MgCl2-H2O solutions, and at the same time predict Ni(II) speciation that is consistent with our XAS and UV-Vis data and with existing literature data up to the solubility limit, resolving a long-standing uncertainty about the role of chloride complexing in this system. PMID:25885410

  11. 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.

  12. Negative Transference Numbers in Polymer Electrolytes

    Science.gov (United States)

    Pesko, Danielle; Timachova, Ksenia; Balsara, Nitash

    Energy density and safety of conventional lithium-ion batteries is limited by the use of flammable organic liquids as a solvent for lithium salts. Polymer electrolytes have the potential to address both limitations. The poor performance of batteries with polymer electrolytes is generally attributed to low ionic conductivity. The purpose of our work is to show that another transport property, the cation transference number, t +, of polymer electrolytes is fundamentally different from that of conventional electrolytes. Our experimental approach, based on concentrated solution theory, indicates that t + of mixtures of poly(ethylene oxide) and LiTFSI salt are negative over most of the accessible concentration window. In contrast, approaches based on dilute solution theory suggest that t + in the same system is positive. In addition to presenting a new approach for determining t +, we also present data obtained from the steady-state current method, pulsed-field-gradient NMR, and the current-interrupt method. Discrepancies between different approaches are resolved. Our work implies that in the absence of concentration gradients, the net fluxes of both cations and anions are directed toward the positive electrode. Conventional liquid electrolytes do not suffer from this constraint.

  13. 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.

  14. [Cancer and electrolytes imbalance].

    Science.gov (United States)

    Shibata, Hiroyuki

    2010-06-01

    The electrolyte imbalance in advanced cancer patients, including hyperkalemia, hypercalcemia and hyponatremia, can be induced by various factors. Hyperkalemia is occasionally induced by chemotherapy for very large malignant tumors, due to tumor lysis syndrome. Hypercalcemia and hyponatremia are often observed in patients with breast cancer, renal cancer, prostate cancer, and the like, as a paraneoplastic syndrome. Some part of hypercalcemia results from osteolysis, but the majority is induced by hormonal factors, such as parathyroid hormone-related protein. One of the paraneoplastic causes of hyponatremia is antidiuretic hormone-producing tumor. These disorders could be morbid or even motile, resulting from encephalopathy or arrhythmia in some cases. However, it should be kept in mind that they could be improved or cured by prompt treatment. Recently, after approval of the molecular targeted drugs for epidermal growth factor receptors, such as cetuximab and panitumumab, the incidence of hypomagnesia with use of these monoclonal antibodies, is relatively frequent. In addition, small molecular targeted drugs, such as m-TORinhibitors and ABL kinase inhibitors, also exert adverse reactions including hypomagnesia and hypophosphatemia. Careful monitoring of the serum concentration of magnesium and phosphate ions, to which little attention was paid previously, is a key issue in these cases.

  15. Low molecular weight salts combined with fluorinated solvents for electrolytes

    Science.gov (United States)

    Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan; Lei, Norman; Guerrero-Zavala, Guillermo; Kwong, Kristie W.

    2015-11-10

    Provided are electrochemical cells and electrolytes used to build such cells. An electrolyte includes at least one salt having a molecular weight less than about 250. Such salts allow forming electrolytes with higher salt concentrations and ensure high conductivity and ion transport in these electrolytes. The low molecular weight salt may have a concentration of at least about 0.5M and may be combined with one or more other salts, such as linear and cyclic imide salts and/or methide salts. The concentration of these additional salts may be less than that of the low molecular weight salt, in some embodiments, twice less. The additional salts may have a molecular weight greater than about 250. The electrolyte may also include one or more fluorinated solvents and may be capable of maintaining single phase solutions at between about -30.degree. C. to about 80.degree. C.

  16. 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

  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 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

  20. 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).

  1. 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.

  2. 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

  3. 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.

  4. Portable Chronic Alcohol Consumption Monitor in Human Sweat through Square-Wave Voltammetry.

    Science.gov (United States)

    Kinnamon, David; Muthukumar, Sriram; Panneer Selvam, Anjan; Prasad, Shalini

    2017-09-01

    Chronic alcohol consumption is a significant financial and physical burden in the United States each year. Alcohol consumption monitors focus on establishing a state of intoxication, not assessing a user's health risks as a function of consumed alcohol. This work demonstrates a biosensor for a chronic alcohol consumption monitor through the electrochemical detection of ethyl glucuronide (EtG) in human sweat using square-wave voltammetry (SWV). A novel affinity assay was demonstrated in which monoclonal antibodies were chemically coabsorbed onto a gold electrode surface in parallel with thiolated charge transfer molecule. Concentration-dependent EtG binding was detected by measuring a reduction in the charge transfer of the sensor, manifesting as a current response during SWV measurement. A companion compact electronic reader was constructed, demonstrating comparable sensitivity to a conventional lab instrument. Both tools demonstrated a limit of detection of 0.1 µg/L and a linear dynamic range of 0.1-100 µg/L corresponding to the physiologically relevant range of EtG expression in human sweat. This device can address the need for a chronic alcohol consumption monitor toward establishing a user's long-term consumption habits to assess the risk of developing specific diseases and conditions associated with regular alcohol consumption, through integration with existing technologies.

  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. 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.

  7. 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.

  8. A wearable biochemical sensor for monitoring alcohol consumption lifestyle through Ethyl glucuronide (EtG) detection in human sweat

    Science.gov (United States)

    Panneer Selvam, Anjan; Muthukumar, Sriram; Kamakoti, Vikramshankar; Prasad, Shalini

    2016-03-01

    We demonstrate for the first time a wearable biochemical sensor for monitoring alcohol consumption through the detection and quantification of a metabolite of ethanol, ethyl glucuronide (EtG). We designed and fabricated two co-planar sensors with gold and zinc oxide as sensing electrodes. We also designed a LED based reporting for the presence of EtG in the human sweat samples. The sensor functions on affinity based immunoassay principles whereby monoclonal antibodies for EtG were immobilized on the electrodes using thiol based chemistry. Detection of EtG from human sweat was achieved through chemiresistive sensing mechanism. In this method, an AC voltage was applied across the two coplanar electrodes and the impedance across the sensor electrodes was measured and calibrated for physiologically relevant doses of EtG in human sweat. EtG detection over a dose concentration of 0.001-100 μg/L was demonstrated on both glass and polyimide substrates. Detection sensitivity was lower at 1 μg/L with gold electrodes as compared to ZnO, which had detection sensitivity of 0.001 μg/L. Based on the detection range the wearable sensor has the ability to detect alcohol consumption of up to 11 standard drinks in the US over a period of 4 to 9 hours.

  9. Electrochemical Impedance Spectroscopy of Polyvinylalcohol Based Gel Electrolyte

    Directory of Open Access Journals (Sweden)

    Nirwan Syarif

    2017-02-01

    Full Text Available Research on the effect of electrolyte ammonium salt, concentration electrolyte with plasticizer to ionic and electronic conductivity of polymer gel electrolyte has been conducted with the variations of two electrolyte NH4Cl-PVA and NH4SCN-PVA at a concentration of 10, 30, 40 (wt%. The measurement of using ionic conductivity by using impedance spectroscopy method showed that the highest value was 0.0156 Scm-1 i.e. in the 54.6% propilen carbonate with 40% NH4Cl and PVA. The lowest value was 0.009 Scm-1 i.e. in the NH4SCN based electrolyte without propilene carbonate and electronic conductivity showed that the highest value was 0.0156 Scm-1 i.e. 40% NH4Cl-PVA and NH4SCN-PVA and the lowest value was 0.009 Scm-1, i.e. in the NH4SCN based electrolyte without propilene carbonate. Factorial analyses showed that the concentrations of electrolyte and the plasticizer affect conductivity value. FTIR (Fourier Transform Infrared measurement showed that the addition of propilene carbonate did not show new bond formation between electrolyte and PVA. It can be shown in absence of characteristic wave number for propilene carbonate and NH4+ ion.

  10. Effect of strong electrolytes on edible oils part III: viscosity of canola ...

    African Journals Online (AJOL)

    Effect of strong electrolytes on the viscosity of canola oil in 1,4 dioxane was undertaken. The viscosity of oil in 1,4 dioxane was found to increase with the concentration of oil and decrease with rise in temperature. Strong electrolytes reduce the rate of flow of oil in 1,4 dioxane. It was noted that amongst these electrolytes, ...

  11. Modeling of electrolytic solutions and implementation of the models in Flowbat

    OpenAIRE

    Hautala, M. (Mia)

    2016-01-01

    Abstract The purpose of this thesis was to create a Flowbat program for the calculation of the activity coefficients of species in different electrolyte solutions. In these solutions, electrolytes have dissociated into ions, which greatly increases the non-ideality of the solution even in small concentrations. Modeling of electrolytic solutions becomes esse...

  12. 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.

  13. 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.

  14. Magnesium removal in the electrolytic zinc industry

    NARCIS (Netherlands)

    Booster, J.L.

    2003-01-01

    Electrolytic zinc plants need to take measures to control the magnesium content in their process liquors, because the natural magnesium bleed does not balance the input from concentrates. Presently used methods are environmentally unfriendly (due to the production of large amounts of waste gypsum)

  15. Surface tension of aqueous electrolyte solutions. Thermodynamics

    NARCIS (Netherlands)

    Drzymala, J.; Lyklema, J.

    2012-01-01

    A thermodynamic theory is developed for obtaining the enthalpic and entropic contributions to the surface excess Gibbs energy of electrolyte solutions from the dependence of the surface tension on concentration and temperature. For elaboration, accurate activity coefficients in solution as functions

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Supersaturated Electrolyte Solutions: Theory and Experiment

    Science.gov (United States)

    Izmailov, Alexander F.; Myerson, Allan S.; Na, Han-Soo

    1995-01-01

    Highly supersaturated electrolyte solutions can be prepared and studied employing an electrodynamic levitator trap (ELT) technique. The ELT technique involves containerless suspension of a microdroplet thus eliminating dust, dirt, and container walls which normally cause heterogeneous nucleation. This allows very high supersaturations to be achieved. A theoretical study of the experimental results obtained for the water activity in microdroplets of various electrolyte solutions is based on the development of the Cahn-Hilliard formalism for electrolyte solutions. In the approach suggested the metastable state for electrolyte solutions is described in terms of the conserved order parameter omega(r,t) associated with fluctuations of the mean solute concentration n(sub 0). Parameters of the corresponding Ginzburg-Landau free energy functional which defines the dynamics of metastable state relaxation are determined and expressed through the experimentally measured quantities. A correspondence of 96-99 % between theory and experiment for all solutions studied was achieved and allowed the determination of an analytical expression for the spinodal concentration n(sub spin), and its calculation for various electrolyte solutions at 298 K. The assumption that subcritical solute clusters consist of the electrically neutral Bjerrum pairs has allowed both analytical and numerical investigation of the number-size N(sub c) of nucleation monomers (aggregates of the Bjerrum pairs) which are elementary units of the solute critical clusters. This has also allowed estimations for the surface tension Alpha, and equilibrium bulk energy Beta per solute molecule in the nucleation monomers. The dependence of these properties on the temperature T and on the solute concentration n(sub 0) through the entire metastable zone (from saturation concentration n(sub sat) to spinodal n(sub spin) is examined. It has been demonstrated that there are the following asymptotics: N(sub c), = I at spinodal

  1. [Sialochemistry in nonneoplastic diseases of parotid gland: immunoglobulins and electrolytes].

    Science.gov (United States)

    Wang, S; Zhu, X; Zhu, J

    1996-07-01

    The concentration and total value of immunoglobulins (SIgA, IgG) and electrolytes (sodium, potassium, chlorine, calcium and phosphorus) in mixed saliva were examined in 28 patients with Sjögren's syndrome (SS), 25 with chronic obstructive parotitis (COP), 32 with sialadenosis and 32 normal controls. The results showed that in SS group, total saliva flow rate was decreased: concentration of SIgA, IgG, electrolytes was significantly elevated; but total value of SIgA, IgG, electrolytes was markedly decreased. Decreased total value of sodium, potassium, chlorine and calcium was revealed in COP group. Elevated concentration and total value of phosphorus was found in sialadenosis group. This study indicates that examination of total value of immunoglobins and electrolytes has greater value than that of concentration. The possible mechanism of changes observed is discussed.

  2. REMOVAL OF COPPER ELECTROLYTE CONTAMINANTS BY ADSORPTION

    Directory of Open Access Journals (Sweden)

    B Gabai

    1997-09-01

    Full Text Available Abstract - Selective adsorbents have become frequently used in industrial processes. Recent studies have shown the possibility of using adsorption to separate copper refinery electrolyte contaminants, with better results than those obtained with conventional techniques. During copper electrorefinning, many impurities may be found as dissolved metals present in the anode slime which forms on the electrode surface, accumulated in the electrolyte or incorporated into the refined copper on the cathode by deposition. In this study, synthetic zeolites, chelating resins and activated carbons were tested as adsorbents to select the best adsorbent performance, as well as the best operating temperature for the process. The experimental method applied was the finite bath, which consists in bringing the adsorbent into contact with a finite volume of electrolyte while controlling the temperature. The concentration of metals in the liquid phase was continuously monitored by atomic absorption spectrophotometry (AAS

  3. 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.

  4. 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.

  5. 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.

  6. [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.

  7. 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.

  8. 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.

  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. 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.

  12. Exercise- and methylcholine-induced sweating responses in older and younger men: effect of heat acclimation and aerobic fitness

    Science.gov (United States)

    Inoue, Y.; Havenith, George; Kenney, W. Larry; Loomis, Joseph L.; Buskirk, Elsworth R.

    The purpose of this investigation was to examine the effects of aging and aerobic fitness on exercise- and methylcholine-induced sweating responses during heat acclimation. Five younger [Y group - age: 23+/-1 (SEM) years; maximal oxygen consumption (V.O2max): 47+/-3 ml.kg-1.min-1], four highly fit older (HO group - 63+/-3 years; 48+/-4 ml.kg-1.min-1) and five normally fit older men (NO group - 67+/-3 years; 30+/-1 ml.kg-1.min-1) who were matched for height, body mass and percentage fat, were heat acclimated by daily cycle exercise ( 35% V.O2max for 90 min) in a hot (43°C, 30% RH) environment for 8 days. The heat acclimation regimen increased performance time, lowered final rectal temperature (Tre) and percentage maximal heart rate (%HRmax), improved thermal comfort and decreased sweat sodium concentration similarly in all groups. Although total body sweating rates (M.sw) during acclimation were significantly greater in the Y and HO groups than in the NO group (Pgroup), the M.sw did not change in all groups with the acclimation sessions. Neither were local sweating rates (m.sw) on chest, back, forearm and thigh changed in all groups by the acclimation. The HO group presented greater forearm m.sw (30-90 min) values and the Y group had greater back and thigh m.sw (early in exercise) values, compared to the other groups (PHO>NO, and on the forearm Y=HO>NO. No group differences were observed for activated sweat gland density at any site. The SGO at the respective sites increased in the post-acclimation test regardless of group (Pgroups than in the Y group. These findings suggest that heat tolerance and the improvement with acclimation are little impaired not only in highly fit older but also normally fit older men, when the subjects exercised at the same relative exercise intensity. Furthermore, the changes induced by acclimation appear associated with an age-related decrease in V.O2max. However methylcholine-activated SGO and the magnitude of improvement of SGO with

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. Recent results on aqueous electrolyte cells

    KAUST Repository

    Wessells, Colin

    2011-03-01

    The improved safety of aqueous electrolytes makes aqueous lithium-ion batteries an attractive alternative to commercial cells utilizing flammable and expensive organic electrolytes. Two important issues relating to their use have been addressed in this work. One is the extension of the usable voltage range by the incorporation of lithium salts, and the other is the investigation of a useful negative electrode reactant, LiTi 2(PO 4) 3. The electrochemical stability of aqueous lithium salt solutions containing two lithium salts, LiNO 3 and Li 2SO 4, has been characterized using a constant current technique. In both cases, concentrated solutions had effective electrolyte stability windows substantially greater than that of pure water under standard conditions. At an electrolyte leakage current of 10 μA cm -2 between two platinum electrodes in 5 M LiNO 3 the cell voltage can reach 2.0 V, whereas with a leakage current of 50 μA cm -2 it can reach 2.3 V. LiTi 2(PO 4) 3 was synthesized using a Pechini method and cycled in pH-neutral Li 2SO 4. At a reaction potential near the lower limit of electrolyte stability, an initial discharge capacity of 118 mAh g -1 was measured at a C/5 rate, while about 90% of this discharge capacity was retained after 100 cycles. This work demonstrates that it is possible to have useful aqueous electrolyte lithium-ion batteries using the LiTi 2(PO 4) 3 anode with cell voltages of 2 V and above. © 2010 Elsevier B.V. All rights reserved.

  1. Understanding Ion Transport in Epoxy-based Polymer Electrolyte

    Science.gov (United States)

    Choi, U. Hyeok; Jang, Hyekyeong; Jung, Byung Mun; Lee, Sang-Bok

    We prepare epoxy-based networked polymer electrolytes including Li salts with either ionic liquids or plastic crystals. The epoxy resins are particularly attractive as polymer matrices for solid polymer electrolytes due to their high mechanical performance combined with good adhesive properties. The selected electrolyte components are allowed to boost ionic conductivity owing to solvating the Li cation and plasticizing the epoxy matrix. As a result, the curing of a homogeneous mixture of epoxy and electrolyte can generate a two-phase system in which the epoxy phase is selected to provide mechanical strength and the electrolyte phase is selected to maximize ionic conductivity. Here, we conduct an investigation of the effect of electrolyte types and their concentration on the conductometric, dielectric and rheological properties of epoxy-based networked polymer electrolytes, using dielectric relaxation spectroscopy and oscillatory shear. These results are complemented by morphology studies in order to understand structure-property relations. Our study leads to insight regarding optimal design of multifunctional electrolytes for energy storage devices.

  2. Liquid Redox Electrolytes for Dye-Sensitized Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ze

    2012-07-01

    This thesis focuses on liquid redox electrolytes in dye-sensitized solar cells (DSCs). A liquid redox electrolyte, as one of the key constituents in DSCs, typically consists of a redox mediator, additives and a solvent. This thesis work concerns all these three aspects of liquid electrolytes, aiming through fundamental insights to enhance the photovoltaic performances of liquid DSCs. Initial attention has been paid to the iodine concentration effects in ionic liquid (IL)-based electrolytes. It has been revealed that the higher iodine concentration required in IL-based electrolytes can be attributed to both triiodide mobility associated with the high viscosity of the IL, and chemical availability of triiodide. The concept of incompletely solvated ionic liquids (ISILs) has been introduced as a new type of electrolyte solvent for DSCs. It has been found that the photovoltaic performance of ISIL-based electrolytes can even rival that of organic solvent-based electrolytes. And most strikingly, ISIL-based electrolytes provide highly stable DSC devices under light-soaking conditions, as a result of the substantially lower vapor pressure of the ISIL system. A significant synergistic effect has been observed when both guanidinium thiocyanate and N-methylbenzimidazole are employed together in an IL-based electrolyte, exhibiting an optimal overall conversion efficiency. Tetrathiafulvalene (TTF) has been investigated as an organic iodine-free redox couple in electrolytes for DSCs. An unexpected worse performance has been observed for the TTF system, albeit it possesses a particularly attractive positive redox potential. An organic, iodine-free thiolate/disulfide system has also been adopted as a redox couple in electrolytes for organic DSCs. An impressive efficiency of 6.0 % has successfully been achieved by using this thiolate/disulfide redox couple in combination with a poly (3, 4-ethylenedioxythiophene) (PEDOT) counter electrode material under full sunlight illumination (AM

  3. 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.

  4. 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...

  5. 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

  6. 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

  7. Halothane anesthesia and serum electrolytes.

    Science.gov (United States)

    Alarcón, O M; Reinosa, J; Medina de Caraballo, M I; Silva, T

    1996-04-01

    The disparate observations on the effect of halothane anesthesia on the serum electrolyte levels in humans prompted us to carry out this work. In this study the levels of sodium, potassium, magnesium, calcium, chloride and inorganic phosphorus were determined in serum of 25 male and 15 female patients, with an age range of 15 to 40 years, who had various pathologies requiring surgery and who were given halothane anesthesia. Significant difference were detected in the concentrations of sodium, potassium, calcium and inorganic phosphorus between presurgical and post-anesthesia induction samples. The truly striking finding in the present study was the significant increase in serum inorganic phosphorus in the intra-operative period. It is suspected that this increase is due to a defect in phosphorylating mechanisms which leads to a rapid hydrolysis of stored and preformed ATP.

  8. 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.

  9. 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.

  10. The investigation of electrolytic surface roughening for PCB copper foil

    Science.gov (United States)

    Lee, Shuo-Jen; Liu, Chao-Kai

    2013-10-01

    This study is the application of the principle of electrochemical. The anodic dissolution has no concentration polarization. Hence, electrolyte life is substantially increased. The waste copper is high in ion concentration with a recovery value. As compared with the current PCB chemical pre-treatment method, it may have advantages of cost-saving, improvement of overall efficiency, reduction of production costs and reduction of the amount of waste generated. In the development of the copper foil for electrochemical roughening process, the use of electrolysis reaction affects the copper surface dissolution to form a unique bump coarsening. It will increase in the surface area of the copper foil to improve dry film solder mask and the adhesion between the copper surfaces. Four electrolytes, two neutral salts and two acids, were selected to explore the best of the electrolytic roughening parameters of temperature, time and voltage. The surface roughness and the surface morphology of the copper foil were measured before and after the electrolytic surface roughening. Finally, after repeated experiments, electrolytes A and B copper generates obvious inter-granular corrosion, resulting in a rough surface similar to the chemical pre-treatment. On the other hands, the surface morphology resulted from electrolytes C and D appears more like pitting. Both electrolytic could generate surface roughness of Ra 0.3 um roughened copper surface higher than industrial standard.

  11. 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

  12. 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.

  13. Electrical properties of cellulose acetate-based polymer gel electrolytes

    Science.gov (United States)

    Abidin, S. Z. Z.; Ali, A. M.; Jaafar, N. K.; Yahya, M. Z. A.

    2017-09-01

    Polymer gel electrolytes based on cellulose acetate with lithium bis(oxalato)borate salt were prepared by dissolving in γ-butyrolactone solvent. The ionic conductivity and dielectric constant of the polymer gel electrolyte samples are investigated using electrochemical impedance spectroscopy over a frequency range from 100 Hz to 1 MHz. The ionic conductivity increased with increasing in the cellulose acetate concentration up to 2.4 wt.% (1.41 × 10-2 S cm-1) and thereafter decreased. The relationship between the dielectric constant and ionic conductivity has been interpreted. The optimum conducting polymer gel electrolyte shows electrochemical stability up to 4.7 V versus Li.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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…

  20. Formation of porous Ge using HF-based electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Flamand, Giovanni; Poortmans, Jef [Microsystems, Components and Packaging Division, IMEC vzw, Kapeldreef 75, 3001 Leuven (Belgium); Dessein, Kristof [Umicore Electro-Optic Materials, Watertorenstraat 33, 2250 Olen (Belgium)

    2005-06-01

    We have performed an extensive study of the porosification of germanium by anodization in HF-based electrolytes. Both n- and p-doped Ge substrates (with varying doping levels) were used, as well as different electrolyte concentrations, anodization currents and times. We will review the conclusions we were able to draw from this series of experiments. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  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. Fire-extinguishing organic electrolytes for safe batteries

    Science.gov (United States)

    Wang, Jianhui; Yamada, Yuki; Sodeyama, Keitaro; Watanabe, Eriko; Takada, Koji; Tateyama, Yoshitaka; Yamada, Atsuo

    2018-01-01

    Severe safety concerns are impeding the large-scale employment of lithium/sodium batteries. Conventional electrolytes are highly flammable and volatile, which may cause catastrophic fires or explosions. Efforts to introduce flame-retardant solvents into the electrolytes have generally resulted in compromised battery performance because those solvents do not suitably passivate carbonaceous anodes. Here we report a salt-concentrated electrolyte design to resolve this dilemma via the spontaneous formation of a robust inorganic passivation film on the anode. We demonstrate that a concentrated electrolyte using a salt and a popular flame-retardant solvent (trimethyl phosphate), without any additives or soft binders, allows stable charge-discharge cycling of both hard-carbon and graphite anodes for more than 1,000 cycles (over one year) with negligible degradation; this performance is comparable or superior to that of conventional flammable carbonate electrolytes. The unusual passivation character of the concentrated electrolyte coupled with its fire-extinguishing property contributes to developing safe and long-lasting batteries, unlocking the limit toward development of much higher energy-density batteries.

  3. Gas Hold-Up in Stirred Tank Reactors in the Presence of Inorganic Electrolytes

    NARCIS (Netherlands)

    Yawalkar, Archis A.; Heesink, Albertus B.M.; Versteeg, Geert F.; Pangarkar, Vishwas G.

    2002-01-01

    Gas hold-up (εG) in air–aqueous electrolyte solutions in stirred tank reactors (STR) is correlated using a relative gas dispersion parameter, N/Ncd and a surface tension factor (STF), (c/z)(dσ/dc)^2. For electrolyte concentration below transition concentration (ct) a single correlation in the form

  4. Gas hold-up in stirred tank reactors in the presence of inorganic electrolytes

    NARCIS (Netherlands)

    Yawalkar, Archis A.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

    2003-01-01

    Gas hold-up (εG) in air-aqueous electrolyte solutions in stirred tank reactors (STR) is correlated using a relative gas dispersion parameter, N/Ncd and a surface tension factor (STF), (c/z)(dδ/dc)2. For electrolyte concentration below transition concentration (ct) a single correlation in the form of

  5. 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.

  6. 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

  7. [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).

  8. Effects of electrolytes on virus inactivation by acidic solutions.

    Science.gov (United States)

    Nishide, Mitsunori; Tsujimoto, Kazuko; Uozaki, Misao; Ikeda, Keiko; Yamasaki, Hisashi; Koyama, A Hajime; Arakawa, Tsutomu

    2011-06-01

    Acidic pH is frequently used to inactivate viruses. We have previously shown that arginine synergizes with low pH in enhancing virus inactivation. Considering a potential application of the acid inactivation of viruses for the prevention and treatment of superficial virus infection at body surfaces and fixtures, herein we have examined the effects of various electrolytes on the acid-induced inactivation of the herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), the influenza A virus (IAV) and the poliovirus upon their incubation at 30˚C for 5 min. Eight electrolytes, i.e., phosphate, NaCl, glutamate, aspartate, pyrrolidone carboxylate, citrate, malate and acetate were tested. No detectable inactivation of the poliovirus was observed under the conditions examined, reflecting its acid-resistance. HSV-1 and HSV-2 responded similarly to the acid-treatment and electrolytes. Some electrolytes showed a stronger virus inactivation than others at a given pH and concentration. The effects of the electrolytes were virus-dependent, as IAV responded differently from HSV-1 and HSV-2 to these electrolytes, indicating that certain combinations of the electrolytes and a low pH can exert a more effective virus inactivation than other combinations and that their effects are virus-specific. These results should be useful in designing acidic solvents for the inactivation of viruses at various surfaces.

  9. 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.

  10. 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.

  11. 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.

  12. [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.

  13. 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.

  14. Improved Cyclability of Liquid Electrolyte Lithium/Sulfur Batteries by Optimizing Electrolyte/Sulfur Ratio

    Directory of Open Access Journals (Sweden)

    Sheng S. Zhang

    2012-12-01

    Full Text Available A liquid electrolyte lithium/sulfur (Li/S cell is a liquid electrochemical system. In discharge, sulfur is first reduced to highly soluble Li2S8, which dissolves into the organic electrolyte and serves as the liquid cathode. In solution, lithium polysulfide (PS undergoes a series of complicated disproportionations, whose chemical equilibriums vary with the PS concentration and affect the cell’s performance. Since the PS concentration relates to a certain electrolyte/sulfur (E/S ratio, there is an optimized E/S ratio for the cyclability of each Li/S cell system. In this work, we study the optimized E/S ratio by measuring the cycling performance of Li/S cells, and propose an empirical method for determination of the optimized E/S ratio. By employing an electrolyte of 0.25 m LiSO3CF3-0.25 m LiNO3 dissolved in a 1:1 (wt:wt mixture of dimethyl ether (DME and 1,3-dioxolane (DOL in an optimized E/S ratio, we show that the Li/S cell with a cathode containing 72% sulfur and 2 mg cm−2 sulfur loading is able to retain a specific capacity of 780 mAh g−1 after 100 cycles at 0.5 mA cm−2 between 1.7 V and 2.8 V.

  15. 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.

  16. 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.

  17. 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.

  18. Solubility of non-polar gases in electrolyte solutions

    Science.gov (United States)

    Walker, R. L., Jr.

    1970-01-01

    Solubility theory describes the effects of both concentration and temperature on solute activity coefficients. It predicts the salting-out effect and the decrease in solubility of non-polar gases with increased electrolyte concentration, and can be used to calculate heats of solution, entropies, and partial molal volumes of dissolved gases

  19. Thermodynamic Studies of Levitated Microdroplets of Highly Supersaturated Electrolyte Solutions

    Science.gov (United States)

    Myerson, Allan S.; Izmailov, Alexander F.; Na, Han-Soo

    1996-01-01

    Highly supersaturated electrolyte solutions are studied by employing an electrodynamic levitator trap (ELT) technique. The ELT technique involves containerless suspension of a microdroplet thus eliminating dust, dirt, and container walls which normally cause heterogeneous nucleation. This allows very high supersaturations to be achieved. A theoretical study of the experimental results obtained for the water activity in microdroplets of various electrolyte solutions is based on the development of the Cahn-Hilliard formalism for electrolyte solutions. A correspondence of 96-99% between the theory and experiment for the all solutions studied was achieved and allowed the determination of an analytical expression for the spinodal concentration n(sub spin) and its calculation for various electrolyte solutions at 298 K.

  20. Evaluation of Electrolytes Imbalance and Dyslipidemia in Diabetic Patients.

    Science.gov (United States)

    Hasona, Nabil A; Elasbali, Abdulbaset

    2016-04-01

    Electrolytes and Lipids have always played significant roles, and changes in their concentrations gives good indications of disease progression in a number of non-communicable diseases. Diabetes mellitus is the most common metabolic disorder in the community. Diabetics may suffer from electrolyte disorders due to complications of diabetes mellitus and the medication they receive. Serum glucose, electrolytes (Na⁺, K⁺, Cl(-) and Ca(++)), and lipid profiles (total cholesterol, triglyceride, and HDL-c) were determined in 100 diabetics and in non-diabetic subjects. All the diabetic patients had a significant (p electrolytes found in diabetics may have great potential as a diagnostic tool in clinical practice and have a significant effect upon the risk of contracting many diseases.

  1. Thermodynamic studies of levitated microdroplets of highly supersaturated electrolyte solutions

    Science.gov (United States)

    Myerson, Allan S.; Izmailov, Alexander F.; Na, Han-Soo

    1996-09-01

    Highly supersaturated electrolyte solutions are studied by employing an electrodynamic levitator trap (ELT) technique. The ELT technique involves containerless suspension of a microdroplet thus eliminating dust, dirt, and container walls which normally cause heterogeneous nucleation. This allows very high supersaturations to be achieved. A theoretical study of the experimental results obtained for the water activity in microdroplets of various electrolyte solutions is based on the development of the Cahn-Hilliard formalism for electrolyte solutions. A correspondence of 96-99% between the theory and experiment for the all solutions studied was achieved and allowed the determination of an analytical expression for the spinodal concentration nspin and its calculation for various electrolyte solutions at 298 K.

  2. Characterization of Pvp Based Solid Polymer Electrolytes Using Spectroscopic Techniques

    Science.gov (United States)

    Ramya, C. S.; Selvasekarapandian, S.; Bhuvaneswari, M. S.; Savitha, T.

    2006-06-01

    Polymer electrolytes based on poly (vinyl pyrrolidone) - ammonium thiocyanate have beeri prepared by solution cast technique. The interaction of salt with the polymer has been examined using Raman spectroscopy. Results revealed that the interaction of the salt has been found to be through the carbonyl group of the polymer matrix. Conductivity measurements showed that these systems conduct ionically. The possible correlation between the conductivity and the structure of these electrolytic systems was also investigated which shows that the conductivity values are directly related to the total "free anion" concentration. Conductivity analysis showed that the addition of ammonium thiocyanate as a dopant in the polymeric electrolyte system enhanced the ionic conductivity. 20 mol% ammonium thiocyanate doped polymer electrolyte exhibits high ionic conductivity and has been found to be 1.7 × 10-4 S cm-1, at room temperature.

  3. Serum electrolytes in children with neurocardiogenic syncope treated with fludrocortisone and salt.

    Science.gov (United States)

    Salim, M A; DiSessa, T G

    1996-07-15

    We examined the changes in serum electrolytes of patients with syncope treated with salt and fludrocortisone. The most significant change was an increase in serum bicarbonate concentration, with minimal alteration of sodium, potassium, and chloride concentrations; none was clinically significant.

  4. 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.

  5. Arrhenius' theory of partial dissociation and hydration of electrolytes in solutions replaces existing activity concepts

    OpenAIRE

    Raji Heyrovska

    2011-01-01

    The author shows that Arrhenius's theory of partial electrolytic dissociation was immaturely displaced about eight decades ago by the empirical concept of ionic activities and the assumption of complete dissociation of electrolytes at all concentrations. The latter brought the theory of electrolytes over the next decades into a complicated state without any physical significance. Therefore, the author started a systematic investigation of the available data and could completely restore t...

  6. 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.

  7. 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.

  8. 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

  9. 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  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. 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.

  19. 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)

  20. 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.

  1. Spectrophotometric studies and applications for the determination of Ni²+ in zinc-nickel alloy electrolyte.

    Science.gov (United States)

    Qiao, Xiaoping; Li, Helin; Zhao, Wenzhen; Li, Dejun

    2012-09-01

    The absorption properties of zinc-nickel alloy electrolyte were studied by visible spectrophotometer. The results show that the relationship between the absorbance of the zinc-nickel alloy electrolyte and Ni(2+) concentration in the electrolyte obeys Beer's law at 660 nm. In addition, other components except Ni(2+) in the zinc-nickel alloy electrolyte such as zinc chloride, ammonium chloride, potassium chloride and boric acid have no obvious effect on the absorbance of zinc-nickel alloy electrolyte. Based on these properties, a new method is developed to determine Ni(2+) concentration in zinc-nickel alloy electrolyte. Comparing with other methods, this method is simple, direct and accurate. Moreover, the whole testing process does not consume any reagent and dilution, and after testing, the electrolyte samples can be reused without any pollution to the environment. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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....

  7. Increase in dermcidin-derived peptides in sweat of patients with atopic eczema caused by a humorous video.

    Science.gov (United States)

    Kimata, Hajime

    2007-01-01

    Dermcidin (DCD)-derived peptide is an antimicrobial peptide produced by the sweat glands. However, the levels of DCD-derived peptide in sweat were decreased in patients with atopic eczema (AE). The effect of viewing a humorous video on the levels of DCD-derived peptide was studied. Twenty patients with AE viewed an 87-min humorous video (Modern Times, featuring Charlie Chaplin). Just before and immediately after viewing, sweat was collected, and the levels of DCD-derived peptide and total protein in sweat were measured. Viewing a humorous video increased the levels of DCD-derived peptide without affecting the levels of total protein in sweat. Viewing a humorous video increased DCD-derived peptide in sweat of patients with AE, and thus, it may be helpful in the treatment of skin infection of AE.

  8. 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.

  9. 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 ...

  10. Potentiometric measurement with a Kelvin probe: Contactless measurement of chloride ions in aqueous electrolyte

    NARCIS (Netherlands)

    Abbas, Yawar; Zhu, X.; de Boer, Hans L.; Tanvir, N.B.; Olthuis, Wouter; van den Berg, Albert

    2016-01-01

    For the first time the chloride ion concentration in electrolyte is measured using a Kelvin probe. A silver-silver chloride (Ag/AgCl) electrode, which is a chloride ion selective electrode, is used as a sample plate in the electrolyte and the Kelvin probe is used as a reference plate that is

  11. Metal-air cell comprising an electrolyte with a room temperature ionic liquid and hygroscopic additive

    Science.gov (United States)

    Friesen, Cody A.; Krishnan, Ramkumar; Tang, Toni; Wolfe, Derek

    2014-08-19

    An electrochemical cell comprising an electrolyte comprising water and a hydrophobic ionic liquid comprising positive ions and negative ions. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. A hydrophilic or hygroscopic additive modulates the hydrophobicity of the ionic liquid to maintain a concentration of the water in the electrolyte is between 0.001 mol % and 25 mol %.

  12. Studies on the Effects of Electrolytes and pH Control on the ...

    African Journals Online (AJOL)

    The effects of electrolytes and pH control on the lipophilic character of fexofenadine hydrochloride was investigated at room temperature. The study was performed by partitioning the drug between 1-octanol and water system. The water system consists of either electrolyte solution of varying concentrations or water adjusted ...

  13. Non-aqueous electrolytes for electrochemical cells

    Science.gov (United States)

    Zhang, Zhengcheng; Dong, Jian; Amine, Khalil

    2016-06-14

    An electrolyte electrochemical device includes an anodic material and an electrolyte, the electrolyte including an organosilicon solvent, a salt, and a hybrid additiving having a first and a second compound, the hybrid additive configured to form a solid electrolyte interphase film on the anodic material upon application of a potential to the electrochemical device.

  14. Antireduction Insulator For Solid-Electrolyte Cell

    Science.gov (United States)

    Shlichta, Paul J.

    1990-01-01

    Depletion of oxygen from electrolyte prevented. Proposed to add layer of electrical insulation between solid electrolyte and portion of porous negative electrode under negative metal contact in solid-electrolyte cell. Helps maintain efficiency of cell by preventing "shadow" effect degrading portion of electrolyte under negative contact and sometimes near seals.

  15. External control of anodic dissolution mechanisms of 100Cr6 in nitrate/chloride mixed electrolytes

    Directory of Open Access Journals (Sweden)

    ANDREAS LESCH

    2011-08-01

    Full Text Available The anodic dissolution of 100Cr6 steel in neutral electrolytes containing sodium chloride and sodium nitrate was investigated potentiodynamically and galvanodynamically with a rotating disc electrode at room temperature. The total concentration of the mixed electrolyte was 3 mol L-1 with variation of chloride/nitrate mole ratios. The potentiodynamic linear sweep voltammograms (LSVs in mixed electrolytes are similar to the LSVs in pure chloride electrolyte at lower current densities and switch to behaviour observed in pure nitrate electrolytes at higher current densities. Provided that both anions are present, it seems that the dissolution reactions at the steel anode are determined by the interface layer only. The effect of these layers on surface quality and current efficiency was also investigated in a flow channel applying galvanostatic pulses. An evidence for different dissolution mechanisms can be seen with an important influence of duty cycle and flow conditions. This allows external control of the desired dissolution mechanism in mixed electrolytes.

  16. Electrolytic decontamination of conductive materials for hazardous waste management

    Energy Technology Data Exchange (ETDEWEB)

    Wedman, D.E.; Martinez, H.E.; Nelson, T.O.

    1996-12-31

    Electrolytic removal of plutonium and americium from stainless steel and uranium surfaces has been demonstrated. Preliminary experiments were performed on the electrochemically based decontamination of type 304L stainless steel in sodium nitrate solutions to better understand the metal removal effects of varying cur-rent density, pH, and nitrate concentration parameters. Material removal rates and changes in surface morphology under these varying conditions are reported. Experimental results indicate that an electropolishing step before contamination removes surface roughness, thereby simplifying later electrolytic decontamination. Sodium nitrate based electrolytic decontamination produced the most uniform stripping of material at low to intermediate pH and at sodium nitrate concentrations of 200 g L{sup -1} and higher. Stirring was also observed to increase the uniformity of the stripping process.

  17. [Electrolyte metabolism and emergency].

    Science.gov (United States)

    Nakao, I; Ito, T; Kasai, N

    1983-02-01

    In outlining the pathology of various electrolyte metabolism abnormalities in cancer patients we considered the main clinical points between pathologies and emergency treatment. In regard to sodium (Na+) metabolism, one pathologic state that requires our attention is hypernatremia. Hypernatremia is accompanied with dehydration and is due to water loss, vomiting, diarrhea and renal insufficiency. One of the major causes of this condition is lack of the antidiuretic hormone due to intracranial metastasis of the tumor. When hypernatremia becomes severe, it is accompanied with circulatory failure, muscular asthenia, disorientation, convulsions, coma and other cerebral symptoms. Treatment consists of replenishing the water content by infusion of electrolyte solutions which should be carefully conducted after complete diagnose of the severity of the patient's pathological condition. Hyponatremia, like sick cell syndrome, is observed relatively frequently in cancer patients. When the serum Na level falls markedly, it induces cerebral edema and causes disorders of consciousness. The major treatment consists of providing both water and sodium supplements. Hyperkalemia is observed at the time of renal insufficiency, tissue lesions, vomiting, and diarrhea. When serum potassium level rises, it causes bradycardia, ventricular fibrillation, or cardiac arrest. It is important to diagnostically apprehend the severity of this condition using EKG and determining the serum K1+ level. For emergency treatment injection of calcium gluconate is very effective. Hypokalemia is often manifested by the loss of intestinal fluids due to diarrhea or during administration of diuretic agents. Clinical symptoms include neural paralysis but emergencies occur relatively infrequently. K C1 injections are used in treating this condition. Hypercalcemia is manifested in cancer patients during hyperparathyroidism. Its clinical symptoms include lassitude, tachycardia, nausea, vomiting, and renal dys

  18. 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.

  19. 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.

  20. Fabrication of titanium dioxide nanotube arrays using organic electrolytes

    Science.gov (United States)

    Yoriya, Sorachon

    This dissertation focuses on fabrication and improvement of morphological features of TiO2 nanotube arrays in the selected organic electrolytes including dimethyl sulfoxide (DMSO; see Chapter 4) and diethylene glycol (DEG; see Chapter 5). Using a polar dimethyl sulfoxide containing hydrofluoric acid, the vertically oriented TiO2 nanotube arrays with well controlled morphologies, i.e. tube lengths ranging from few microns up to 101 microm, pore diameters from 100 nm to 150 nm, and wall thicknesses from 15 nm to 50 nm were achieved. Various anodization variables including fluoride ion concentration, voltage, anodization time, water content, and reuse of the anodized electrolyte could be manipulated under proper conditions to control the nanotube array morphology. Anodization current behaviors associated with evolution of nanotube length were analyzed in order to clarify and better understand the formation mechanism of nanotubes grown in the organic electrolytes. Typically observed for DMSO electrolyte, the behavior that anodization current density gradually decreases with time is a reflection of a constant growth rate of nanotube arrays. Large fluctuation of anodization current was significantly observed probably due to the large change in electrolyte properties during anodization, when anodizing in high conductivity electrolytes such as using high HF concentration and reusing the anodized electrolyte as a second time. It is believed that the electrolyte properties such as conductivity and polarity play important role in affecting ion solvation and interactions in the solution consequently determining the formation of oxide film. Fabrication of the TiO2 nanotube array films was extended to study in the more viscous diethylene glycol (DEG) electrolyte. The arrayed nanotubes achieved from DEG electrolytes containing either HF or NH4 F are fully separated, freely self-standing structure with open pores and a wide variation of tube-to-tube spacing ranging from drug

  1. Epidermal Microfluidic Electrochemical Detection System: Enhanced Sweat Sampling and Metabolite Detection.

    Science.gov (United States)

    Martín, Aida; Kim, Jayoung; Kurniawan, Jonas F; Sempionatto, Juliane R; Moreto, Jose R; Tang, Guangda; Campbell, Alan S; Shin, Andrew; Lee, Min Yul; Liu, Xiaofeng; Wang, Joseph

    2017-12-22

    Despite tremendous recent efforts, noninvasive sweat monitoring is still far from delivering its early analytical promise. Here, we describe a flexible epidermal microfluidic detection platform fabricated through hybridization of lithographic and screen-printed technologies, for efficient and fast sweat sampling and continuous, real-time electrochemical monitoring of glucose and lactate levels. This soft, skin-mounted device judiciously merges lab-on-a-chip and electrochemical detection technologies, integrated with a miniaturized flexible electronic board for real-time wireless data transmission to a mobile device. Modeling of the device design and sweat flow conditions allowed optimization of the sampling process and the microchannel layout for achieving attractive fluid dynamics and rapid filling of the detection reservoir (within 8 min from starting exercise). The wearable microdevice thus enabled efficient natural sweat pumping to the electrochemical detection chamber containing the enzyme-modified electrode transducers. The fabricated device can be easily mounted on the epidermis without hindrance to the wearer and displays resiliency against continuous mechanical deformation expected from such epidermal wear. Amperometric biosensing of lactate and glucose from the rapidly generated sweat, using the corresponding immobilized oxidase enzymes, was wirelessly monitored during cycling activity of different healthy subjects. This ability to monitor sweat glucose levels introduces new possibilities for effective diabetes management, while similar lactate monitoring paves the way for new wearable fitness applications. The new epidermal microfluidic electrochemical detection strategy represents an attractive alternative to recently reported colorimetric sweat-monitoring methods, and hence holds considerable promise for practical fitness or health monitoring applications.

  2. Long-term outcomes of children with intermediate sweat chloride values in infancy.

    Science.gov (United States)

    Groves, Tyler; Robinson, Paul; Wiley, Veronica; Fitzgerald, Dominic A

    2015-06-01

    To describe the clinical course of children who have intermediate sweat chloride values on initial screening for cystic fibrosis (CF). We performed a retrospective review of children with intermediate sweat chloride values (raised immunoreactive trypsinogen/1 copy of p.F508del CF mutation on newborn screening (NBS)/sweat chloride value of 30-59 mmol/L) presenting to The Children's Hospital at Westmead over 15 years. Patients with an intermediate sweat chloride evolving to a formal diagnosis of CF (termed "delayed CF") were matched (2:1) with NBS positive patients with CF (termed "NBS positive CF"). Clinical outcomes were compared. Fourteen of 29 (48%, 95% CI 0.3-0.66) patients with intermediate sweat chloride value evolved to a diagnosis of CF and were matched with 28 NBS positive patients with CF. Delayed CF had less pancreatic insufficiency (OR 0.06, 95% CI 0.01-0.44, P = .006), less colonization with nonmucoid Pseudomonas aeruginosa (OR 0.04, 95% CI 0.01-0.38, P = .005), milder obstructive lung disease (forced expiratory volume in 1 second/forced vital capacity ratio), and overall disease severity (Shwachman scores) at 10 years (mean difference 5.93, 95% CI 0.39-11.46, P = .04; mean difference 4.72, 95% CI 0.9-8.53, P = .015, respectively). Nutritional outcomes were better at 2 years for delayed CF but did not persist to later ages. In this cohort, approximately one-half of infants with intermediate sweat chloride value were later diagnosed with CF. The clinical course of delayed CF was milder in some aspects compared with NBS positive CF. These results emphasize the importance of ongoing follow-up of infants with intermediate sweat chloride values. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  3. Electrolytic formation of carbon nanostructures

    Science.gov (United States)

    Hsu, W. K.; Terrones, M.; Hare, J. P.; Terrones, H.; Kroto, H. W.; Walton, D. R. M.

    1996-11-01

    Carbon nanotubes (with and without encapsulated material) as well as nanoparticles and onion-like structures have been generated by electrolysis in molten alkali halide salts using carbon electrodes under an argon atmosphere. The nature of the products depends upon several factors including the electrolysis voltage and current, depth of electrode immersion in the electrolyte, the length of time the current is maintained and the electrolyte.

  4. Electrolytes for lithium ion batteries

    Science.gov (United States)

    Vaughey, John; Jansen, Andrew N.; Dees, Dennis W.

    2014-08-05

    A family of electrolytes for use in a lithium ion battery. The genus of electrolytes includes ketone-based solvents, such as, 2,4-dimethyl-3-pentanone; 3,3-dimethyl 2-butanone(pinacolone) and 2-butanone. These solvents can be used in combination with non-Lewis Acid salts, such as Li.sub.2[B.sub.12F.sub.12] and LiBOB.

  5. Cosolvent electrolytes for electrochemical devices

    Energy Technology Data Exchange (ETDEWEB)

    Wessells, Colin Deane; Firouzi, Ali; Motallebi, Shahrokh; Strohband, Sven

    2018-02-13

    A system and method for stabilizing electrodes against dissolution and/or hydrolysis including use of cosolvents in liquid electrolyte batteries for three purposes: the extension of the calendar and cycle life time of electrodes that are partially soluble in liquid electrolytes, the purpose of limiting the rate of electrolysis of water into hydrogen and oxygen as a side reaction during battery operation, and for the purpose of cost reduction.

  6. Cosolvent electrolytes for electrochemical devices

    Energy Technology Data Exchange (ETDEWEB)

    Wessells, Colin Deane; Firouzi, Ali; Motallebi, Shahrokh; Strohband, Sven

    2018-01-23

    A method for stabilizing electrodes against dissolution and/or hydrolysis including use of cosolvents in liquid electrolyte batteries for three purposes: the extension of the calendar and cycle life time of electrodes that are partially soluble in liquid electrolytes, the purpose of limiting the rate of electrolysis of water into hydrogen and oxygen as a side reaction during battery operation, and for the purpose of cost reduction.

  7. Solid polymer electrolyte lithium batteries

    Science.gov (United States)

    Alamgir, Mohamed; Abraham, Kuzhikalail M.

    1993-01-01

    This invention pertains to Lithium batteries using Li ion (Li.sup.+) conductive solid polymer electrolytes composed of solvates of Li salts immobilized in a solid organic polymer matrix. In particular, this invention relates to Li batteries using solid polymer electrolytes derived by immobilizing solvates formed between a Li salt and an aprotic organic solvent (or mixture of such solvents) in poly(vinyl chloride).

  8. Neurologic manifestations of major electrolyte abnormalities.

    Science.gov (United States)

    Diringer, M

    2017-01-01

    The brain operates in an extraordinarily intricate environment which demands precise regulation of electrolytes. Tight control over their concentrations and gradients across cellular compartments is essential and when these relationships are disturbed neurologic manifestations may develop. Perturbations of sodium are the electrolyte disturbances that most often lead to neurologic manifestations. Alterations in extracellular fluid sodium concentrations produce water shifts that lead to brain swelling or shrinkage. If marked or rapid they can result in profound changes in brain function which are proportional to the degree of cerebral edema or contraction. Adaptive mechanisms quickly respond to changes in cell size by either increasing or decreasing intracellular osmoles in order to restore size to normal. Unless cerebral edema has been severe or prolonged, correction of sodium disturbances usually restores function to normal. If the rate of correction is too rapid or overcorrection occurs, however, new neurologic manifestations may appear as a result of osmotic demyelination syndrome. Disturbances of magnesium, phosphate and calcium all may contribute to alterations in sensorium. Hypomagnesemia and hypocalcemia can lead to weakness, muscle spasms, and tetany; the weakness from hypophosphatemia and hypomagnesemia can impair respiratory function. Seizures can be seen in cases with very low concentrations of sodium, magnesium, calcium, and phosphate. © 2017 Elsevier B.V. All rights reserved.

  9. 5α-Androst-16-en-3α-ol β-D-glucuronide, precursor of 5α-androst-16-en-3α-ol in human sweat.

    Science.gov (United States)

    Starkenmann, Christian; Mayenzet, Fabienne; Brauchli, Robert; Troccaz, Myriam

    2013-12-01

    5α-Androst-16-en-3α-ol (α-androstenol) is an important contributor to human axilla sweat odor. It is assumed that α-andostenol is excreted from the apocrine glands via a H2 O-soluble conjugate, and this precursor was formally characterized in this study for the first time in human sweat. The possible H2 O-soluble precursors, sulfate and glucuronide derivatives, were synthesized as analytical standards, i.e., α-androstenol, β-androstenol sulfates, 5α-androsta-5,16-dien-3β-ol (β-androstadienol) sulfate, α-androstenol β-glucuronide, α-androstenol α-glucuronide, β-androstadienol β-glucuronide, and α-androstenol β-glucuronide furanose. The occurrence of α-androstenol β-glucuronide was established by ultra performance liquid chromatography (UPLC)/MS (heated electrospray ionization (HESI)) in negative-ion mode in pooled human sweat, containing eccrine and apocrine secretions and collected from 25 female and 24 male underarms. Its concentration was of 79 ng/ml in female secretions and 241 ng/ml in male secretions. The release of α-androstenol was observed after incubation of the sterile human sweat or α-androstenol β-glucuronide with a commercial glucuronidase enzyme, the urine-isolated bacteria Streptococcus agalactiae, and the skin bacteria Staphylococcus warneri DSM 20316, Staphylococcus haemolyticus DSM 20263, and Propionibacterium acnes ATCC 6919, reported to have β-glucuronidase activities. We demonstrated that if α- and β-androstenols and androstadienol sulfates were present in human sweat, their concentrations would be too low to be considered as potential precursors of malodors; therefore, the H2 O-soluble precursor of α-androstenol in apocrine secretion should be a β-glucuronide. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  10. Experimental investigation into the transmembrane electrical potential of the forward osmosis membrane process in electrolyte solutions.

    Science.gov (United States)

    Bian, Lixia; Fang, Yanyan; Wang, Xiaolin

    2014-06-19

    The transmembrane electrical potential (TMEP) in a forward osmosis membrane process with a single electrolyte solution as the draw and feed solutions was investigated by experiments. The effects of membrane orientation, the electrolyte species (KCl, NaCl, MgCl2, and CaCl2), concentration and concentration ratio of solutions at both sides of membrane on water flux and TMEP were investigated. The results showed that the TMEPs at different membrane orientation cannot completely coincide, which confirmed the effect of membrane asymmetry. The ion diffusion coefficients significantly affected the TMEP across the membrane, with different patterns for different electrolytes and concentrations.

  11. Experimental Investigation into the Transmembrane Electrical Potential of the Forward Osmosis Membrane Process in Electrolyte Solutions

    Directory of Open Access Journals (Sweden)

    Lixia Bian

    2014-06-01

    Full Text Available The transmembrane electrical potential (TMEP in a forward osmosis membrane process with a single electrolyte solution as the draw and feed solutions was investigated by experiments. The effects of membrane orientation, the electrolyte species (KCl, NaCl, MgCl2, and CaCl2, concentration and concentration ratio of solutions at both sides of membrane on water flux and TMEP were investigated. The results showed that the TMEPs at different membrane orientation cannot completely coincide, which confirmed the effect of membrane asymmetry. The ion diffusion coefficients significantly affected the TMEP across the membrane, with different patterns for different electrolytes and concentrations.

  12. Electrolytes: Sodium Disorders.

    Science.gov (United States)

    Braun, Michael M; Mahowald, Megan

    2017-08-01

    Sodium disorders (ie, hyponatremia, hypernatremia) are common electrolyte disturbances in clinical medicine and are associated with increased rates of morbidity and mortality. Etiologies of hyponatremia are classified into four categories. The first is pseudohyponatremia, in which the sodium level is low due to hyperproteinemia, hyperlipidemia, or hyperglycemia. The other three categories are based on overall patient fluid status and include hypovolemic (commonly due to fluid loss), hypervolemic (commonly due to fluid retention from heart failure, cirrhosis, or renal failure), and euvolemic (most often because of syndrome of inappropriate secretion of antidiuretic hormone). Hypovolemic hyponatremia is managed by rehydration with isotonic saline. Hypervolemic hyponatremia is managed by addressing the underlying cause. Euvolemic hyponatremia is managed by restricting free water intake, addressing the underlying cause, and occasionally with drugs (eg, vasopressin receptor antagonists). Patients with severe or acutely symptomatic hyponatremia (eg, altered mental status, seizures), including those with acute symptomatic exercise-induced hyponatremia, require urgent treatment. This should consist of hypertonic saline administration along with monitoring of sodium levels to avoid overly rapid correction. Hypernatremia most often occurs because of water loss or inadequate water intake. Depending on severity, management involves oral or intravenous hypotonic fluids and addressing the underlying cause. Written permission from the American Academy of Family Physicians is required for reproduction of this material in whole or in part in any form or medium.

  13. 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.

  14. Differential-concentration scanning ion conductance microscopy

    OpenAIRE

    Perry, David; Page, Ashley; Chen, Baoping; Frenguelli, Bruno G.; Unwin, Patrick R.

    2017-01-01

    Scanning ion conductance microscopy (SICM) is a nanopipette-based scanning probe microscopy technique that utilizes the ionic current flowing between an electrode inserted inside a nanopipette probe containing electrolyte solution and a second electrode placed in a bulk electrolyte bath, to provide information on a substrate of interest. For most applications to date, the composition and concentration of the electrolyte inside and outside the nanopipette is identical, but it is shown herein t...

  15. Skin pretreatment with microneedles prior to pilocarpine iontophoresis increases sweat production.

    Science.gov (United States)

    Wing, David; Prausnitz, Mark R; Buono, Michael J

    2013-11-01

    Collection of sweat via pilocarpine iontophoresis is commonly used to diagnose cystic fibrosis (CF), with thousands of tests performed each day. The main source of resistance to the passage of pilocarpine ions to the sweat glands is the electrical resistance of the stratum corneum. It was hypothesized that pretreating the skin with 0·5 mm-long microneedles would significantly decrease this resistance, thus increasing pilocarpine's permeation into the skin. Improved permeation should result in significantly reduced time to sweat initiation, time to collection of a clinically meaningful amount of sweat, and increased total amount of sweat produced in 15 min. Subjects (n = 12) had two 5 cm(2) areas on the forearm measured, marked and randomized to experimental (microneedles + iontophoresis) or control (iontophoresis alone). Microneedle pretreatment was conducted using a 35-needle microneedle stamp in a manner that 20 applications completely covered the 5 cm(2) treatment area. This was repeated five times for a total of 100 applications. Both experimental and control sites were placed under iontophoresis (1·5 mA) for 5 min. Microneedle pretreatment significantly decreased mean skin resistance (260 ± 27 kΩ versus 160 ± 19 kΩ, P = 0·006), while significantly increasing mean sweat rate (0·76 ± 0·35 versus 0·54 ± 0·19 μl cm(2) min(-1) , P = 0·007). No significant difference was found concerning pain (P = 0·059), number of active sweat glands (P = 0·627) or the osmolality of the collected sweat (P = 0·636). The results of this study suggest that microneedle pretreatment prior to pilocarpine iontophoresis significantly increases sweat production. Such results have the potential to improve the methodology currently used to diagnose cystic fibrosis and, more broadly, to administer drugs via the skin. © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  16. Acid-base properties of electrolytic manganese dioxide in aqueous electrolyte solution 3. International common sample number 1-RNO sub 3 (R :Li ,K ) solution system

    Energy Technology Data Exchange (ETDEWEB)

    Tari, Isao; Tokin, Yasushi; Nakahara, Takashi; Hirai, Taketsugu (Okayama Univ., Faculty of Engineering, Okayama, Japan Osaka City Univ., Faculty of Engineering Osaka (Japan))

    1989-07-05

    Behavior of electrolytic manganese dioxide as acid and base in the electrolyte solution of lithium and pottasium nitrates international common sample was studied. Regarding electrolytic manganese dioxide, special treatment was applied for removing Na , treatment method for it was explained. Experiment was conducted by potentiometric titration, continuously and intermittently, Concentration of each ion was measured by atomic absorption to obtain adsorbed quantity of it by electrolytic manganese dioxide. As the result of experiment, those were obtained that, in case pH was higher than 3, electrolytic manganese dioxide acted as acid by releasing H , and at the same time, equivalent amount of Li or K was adsorbed, the quantity of which depended on pH value. As the consideration on experimental result, it was concluded that Li or K was adsorbed at different location. 11 refs., 6 figs.

  17. Comparison between fixed and fluidized bed cathodes and effect of supporting electrolyte in electrochemical removal of copper ion from dilute solutions

    Directory of Open Access Journals (Sweden)

    I.A. Khattab

    2014-03-01

    Experimental study of the role of the supporting electrolyte in electrolytic cells confirmed that, type and concentration of supporting electrolyte have a remarkable effect on the two aforementioned parameters as well as the rate of removal. Using of NaCl showed better results than Na2SO4.

  18. Correlation of sweat chloride and percent predicted FEV1in cystic fibrosis patients treated with ivacaftor.

    Science.gov (United States)

    Fidler, Meredith C; Beusmans, Jack; Panorchan, Paul; Van Goor, Fredrick

    2017-01-01

    Ivacaftor, a CFTR potentiator that enhances chloride transport by acting directly on CFTR to increase its channel gating activity, has been evaluated in patients with different CFTR mutations. Several previous analyses have reported no statistical correlation between change from baseline in ppFEV 1 and reduction in sweat chloride levels for individuals treated with ivacaftor. The objective of the post hoc analysis described here was to expand upon previous analyses and evaluate the correlation between sweat chloride levels and absolute ppFEV 1 changes across multiple cohorts of patients with different CF-causing mutations who were treated with ivacaftor. The goal of the analysis was to help define the potential value of sweat chloride as a pharmacodynamic biomarker for use in CFTR modulator trials. For any given study, reductions in sweat chloride levels and improvements in absolute ppFEV 1 were not correlated for individual patients. However, when the data from all studies were combined, a statistically significant correlation between sweat chloride levels and ppFEV 1 changes was observed (psweat chloride level changes in response to potentiation of the CFTR protein by ivacaftor appear to be a predictive pharmacodynamic biomarker of lung function changes on a population basis but are unsuitable for the prediction of treatment benefits for individuals. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Feasibility and normal values of an integrated conductivity (Nanoduct™) sweat test system in healthy newborns.

    Science.gov (United States)

    Kuehni, Claudia E; Schindler, Matthias; Mazur, Agnieszka; Malzacher, Andreas; Hornung, René; Barben, Juerg

    2017-07-01

    Nanoduct™ is a simple and practical sweat analysis system measuring conductivity in situ. It requires only three microlitres of sweat, making it especially applicable to newborns. We measured conductivity in 260 healthy term infants at the age of four days, and again at four weeks to determine the proportion of successful tests, test duration, and normal values for sweat conductivity in newborns. Sufficient sweat was collected in 159/260 of four-day olds (61%), and in 225/239 of four-week olds (94%). Mean (sd) test duration was 27 (5) and 25 (5) min. Mean (sd, range) conductivity was 53mmol/l (16, 8-114) at age four days, and 36 (9, 12-64) at four weeks. Determination of sweat conductivity using Nanoduct™ cannot be recommended for four-day old newborns. However, at the age of four weeks the success rate is high (94%), and conductivity values at that age are comparable to older healthy children. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  20. Realistic Facial Expression of Virtual Human Based on Color, Sweat, and Tears Effects

    Directory of Open Access Journals (Sweden)

    Mohammed Hazim Alkawaz

    2014-01-01

    Full Text Available Generating extreme appearances such as scared awaiting sweating while happy fit for tears (cry and blushing (anger and happiness is the key issue in achieving the high quality facial animation. The effects of sweat, tears, and colors are integrated into a single animation model to create realistic facial expressions of 3D avatar. The physical properties of muscles, emotions, or the fluid properties with sweating and tears initiators are incorporated. The action units (AUs of facial action coding system are merged with autonomous AUs to create expressions including sadness, anger with blushing, happiness with blushing, and fear. Fluid effects such as sweat and tears are simulated using the particle system and smoothed-particle hydrodynamics (SPH methods which are combined with facial animation technique to produce complex facial expressions. The effects of oxygenation of the facial skin color appearance are measured using the pulse oximeter system and the 3D skin analyzer. The result shows that virtual human facial expression is enhanced by mimicking actual sweating and tears simulations for all extreme expressions. The proposed method has contribution towards the development of facial animation industry and game as well as computer graphics.

  1. Realistic facial expression of virtual human based on color, sweat, and tears effects.

    Science.gov (United States)

    Alkawaz, Mohammed Hazim; Basori, Ahmad Hoirul; Mohamad, Dzulkifli; Mohamed, Farhan

    2014-01-01

    Generating extreme appearances such as scared awaiting sweating while happy fit for tears (cry) and blushing (anger and happiness) is the key issue in achieving the high quality facial animation. The effects of sweat, tears, and colors are integrated into a single animation model to create realistic facial expressions of 3D avatar. The physical properties of muscles, emotions, or the fluid properties with sweating and tears initiators are incorporated. The action units (AUs) of facial action coding system are merged with autonomous AUs to create expressions including sadness, anger with blushing, happiness with blushing, and fear. Fluid effects such as sweat and tears are simulated using the particle system and smoothed-particle hydrodynamics (SPH) methods which are combined with facial animation technique to produce complex facial expressions. The effects of oxygenation of the facial skin color appearance are measured using the pulse oximeter system and the 3D skin analyzer. The result shows that virtual human facial expression is enhanced by mimicking actual sweating and tears simulations for all extreme expressions. The proposed method has contribution towards the development of facial animation industry and game as well as computer graphics.

  2. Realistic Facial Expression of Virtual Human Based on Color, Sweat, and Tears Effects

    Science.gov (United States)

    Alkawaz, Mohammed Hazim; Basori, Ahmad Hoirul; Mohamad, Dzulkifli; Mohamed, Farhan

    2014-01-01

    Generating extreme appearances such as scared awaiting sweating while happy fit for tears (cry) and blushing (anger and happiness) is the key issue in achieving the high quality facial animation. The effects of sweat, tears, and colors are integrated into a single animation model to create realistic facial expressions of 3D avatar. The physical properties of muscles, emotions, or the fluid properties with sweating and tears initiators are incorporated. The action units (AUs) of facial action coding system are merged with autonomous AUs to create expressions including sadness, anger with blushing, happiness with blushing, and fear. Fluid effects such as sweat and tears are simulated using the particle system and smoothed-particle hydrodynamics (SPH) methods which are combined with facial animation technique to produce complex facial expressions. The effects of oxygenation of the facial skin color appearance are measured using the pulse oximeter system and the 3D skin analyzer. The result shows that virtual human facial expression is enhanced by mimicking actual sweating and tears simulations for all extreme expressions. The proposed method has contribution towards the development of facial animation industry and game as well as computer graphics. PMID:25136663

  3. The effect of electrolytes on emulsions stabilized by nonionic surfactants

    NARCIS (Netherlands)

    Boomgaard, van den A.

    1985-01-01

    The objective of this study was to investigate the effect of high electrolyte concentrations on the stability of oil-in-water- emulsions stabilized by nonionic surfactants.

    In chapter 1 several stability mechanisms are briefly outlined and the distinction between coalescence and

  4. Electrolyte Solutions and Specific Ion Effects on Interfaces

    Science.gov (United States)

    Friedman, Ran

    2013-01-01

    Introductory general and physical chemistry courses often deal with colligative properties of solutions and do not discuss nonideal solutions in detail. Yet, a growing body of evidence reveals that even at physiological concentrations electrolyte solutions cannot be treated as ideal when a charged or partially charged solute (such as a protein) is…

  5. Reference Values for Plasma Electrolytes and Urea in Nigerian ...

    African Journals Online (AJOL)

    Reference values for plasma electrolytes and urea have been defined for Nigerian children and adolescents residing in Abeokuta and its environs, a location in southern Nigeria, by estimating plasma sodium, potassium bicarbonate and urea concentrations in a reference population. The study group comprised three ...

  6. In Vivo Readout of CFTR Function: Ratiometric Measurement of CFTR-Dependent Secretion by Individual, Identifiable Human Sweat Glands

    Science.gov (United States)

    Wine, Jeffrey J.; Char, Jessica E.; Chen, Jonathan; Cho, Hyung-ju; Dunn, Colleen; Frisbee, Eric; Joo, Nam Soo; Milla, Carlos; Modlin, Sara E.; Park, Il-Ho; Thomas, Ewart A. C.; Tran, Kim V.; Verma, Rohan; Wolfe, Marlene H.

    2013-01-01

    To assess CFTR function in vivo, we developed a bioassay that monitors and compares CFTR-dependent and CFTR-independent sweat secretion in parallel for multiple (∼50) individual, identified glands in each subject. Sweating was stimulated by intradermally injected agonists and quantified by optically measuring spherical sweat bubbles in an oil-layer that contained dispersed, water soluble dye particles that partitioned into the sweat bubbles, making them highly visible. CFTR-independent secretion (M-sweat) was stimulated with methacholine, which binds to muscarinic receptors and elevates cytosolic calcium. CFTR-dependent secretion (C-sweat) was stimulated with a β-adrenergic cocktail that elevates cytosolic cAMP while blocking muscarinic receptors. A C-sweat/M-sweat ratio was determined on a gland-by-gland basis to compensate for differences unrelated to CFTR function, such as gland size. The average ratio provides an approximately linear readout of CFTR function: the heterozygote ratio is ∼0.5 the control ratio and for CF subjects the ratio is zero. During assay development, we measured C/M ratios in 6 healthy controls, 4 CF heterozygotes, 18 CF subjects and 4 subjects with ‘CFTR-related’ conditions. The assay discriminated all groups clearly. It also revealed consistent differences in the C/M ratio among subjects within groups. We hypothesize that these differences reflect, at least in part, levels of CFTR expression, which are known to vary widely. When C-sweat rates become very low the C/M ratio also tended to decrease; we hypothesize that this nonlinearity reflects ductal fluid absorption. We also discovered that M-sweating potentiates the subsequent C-sweat response. We then used potentiation as a surrogate for drugs that can increase CFTR-dependent secretion. This bioassay provides an additional method for assessing CFTR function in vivo, and is well suited for within-subject tests of systemic, CFTR-directed therapeutics. PMID:24204751

  7. ELECTROLYTIC-PLASMA TREATMENT OF INNER SURFACE OF TUBULAR PRODUCTS

    Directory of Open Access Journals (Sweden)

    Yu. G. Alekseev

    2016-01-01

    Full Text Available While manufacturing a number of important tubular products stringent requirements have been imposed on quality of their inner surfaces. The well-known methods for inner surface treatment of pipes include sandblasting, chemical cleaning with acid reagents (oxalic, formic, sulfamic, orthophosphoric acids and electrochemical polishing. Disadvantages of the chemical method are cleaning-up irregularities, high metal removal, limited number of reagent application, complicated selection of reagent chemical composition and concentration, complicated and environmentally harmful recycling of waste chemicals, high cost of reagents. Low productivity at a high cost, as well as hazardous impact on personnel due to high dispersion of abrasive dust are considered as disadvantages of sandblasting. Electrochemical polishing is characterized by the following disadvantages: low processing productivity because supply of high currents is rather difficult due to electrolyte scattering capacity away from the main electrode action zone, limited length of the cavity to be treated due to heating of flexible current leads at operating current densities, application of expensive aggressive electrolytes and high costs of their recycling. A new method for polishing and cleaning of inner surfaces of tubular products based on electrolyte-plasma treatment has been developed. In comparison with the existing methods the proposed methods ensures quality processing with high intensity while applying non-toxic, environmentally friendly and cheap electrolytes. The paper presents results of investigations on technological specific features of electrolyte-plasma treatment for inner surfaces of tubular products: influence of slotted nozzle width, electrolyte flow and rate on stability of gas-vapor blanket, current density and productivity. Results of the research have made it possible to determine modes that provide stability and high productivity in the process of electrolyte

  8. Eccrine sweat gland anatomy in cockayne syndrome: a possible diagnostic aid.

    Science.gov (United States)

    Landing, B H; Sugarman, G; Dixon, L G

    1983-01-01

    Cockayne syndrome is an autosomal recessive disease, which includes as major features motor and mental retardation (beginning in the second year), microcephaly, ataxia, retinal degeneration and pigmentation, cataracts, progeroid features, intracranial calcification, hypogonadism, and growth retardation. Many other diseases have some of these features, so that diagnosis of Cockayne syndrome can be difficult, especially in younger children. Eccrine sweat glands were microdissected from autopsy or biopsy specimens from patients with Cockayne syndrome, and mean values for duct length, secretory coil volume, ratio of coil volume to duct length, and axis ratio of the secretory coil were determined. In comparison with values for eccrine glands of patients with no known genetic or chromosomal disease, eccrine glands in Cockayne syndrome are abnormally small for age. Whether other diseases with various similarities to Cockayne syndrome produce similar growth abnormality of eccrine sweat glands is not known, but determination of sweat gland size may provide data suggesting or supporting the diagnosis of Cockayne syndrome.

  9. Multivalent weak electrolytes - risky background electrolytes for capillary zone electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Beckers, J. L.; Boček, Petr

    2002-01-01

    Roč. 23, č. 12 (2002), s. 1942-1946 ISSN 0173-0835 R&D Projects: GA ČR GA203/99/0044; GA ČR GA203/02/0023; GA ČR GA203/01/0401; GA AV ČR IAA4031703; GA AV ČR IAA4031103 Institutional research plan: CEZ:AV0Z4031919 Keywords : background electrolytes * capillary zone electrophoresis * multivalent electrolytes Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.325, year: 2002

  10. The influences of electrolyte on rheological properties of Poyang lake sand

    Science.gov (United States)

    Wang, Peiyu; Chen, Xi; Qin, Ziqi; Zhu, Zhongfan

    2017-08-01

    The investigation on the influences of electrolyte and flow shear on rheological properties of highly-concentrated cohesive sediment suspension is an important subject in the context of sediment transport dynamics. By means of experiment measurement and theoretical analysis, this project studies the influence of electrolyte (valence of cation and concentration) on the rigidity (or viscosity) and yield stress of highly-concentrated cohesive sediment suspension under a static condition, then discusses a possible explanation involved in the role which is played by electrolyte in determinations of rigidity and yield stress of the suspension considering the influences of all factors such as electrolyte condition, primary sediment concentration, median size and size distribution of sediment particle.

  11. Electroless copper electrolytes and its surface characteristics for semiconductor interconnects

    Science.gov (United States)

    Lee, Hong-Kee; Hur, Jin-Young

    2013-07-01

    In this research, to develop proper electroless copper electrolytes for semiconductor interconnects, the concentration and amount of additives are varied. Then, the stability, reactivity, deposition rate, leveling effect, and surface structure are examined. After a virgin makeup solution with suitable deposition characteristics is obtained, an electroless copper coating layer of high uniformity and adhesion strength was achieved using the stabilizer, catalyst, buffer, and pH adjuster as additives and surfactant on Ru diffusion barriers. Through annealing, resistance characteristics could be enhanced. Moreover, by measuring the cyclic voltammetry stripping and mixed potential of the electroless Cu electrolyte, its surface reactivity is electrochemically evaluated, and the result is in agreement with the deposition reaction. When the electrolyte developed in this study is applied on a trench pattern wafer with A/R 3.5 and a line width of 30 nm, it is possible to observe immaculate filling with improved leveling.

  12. 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.

  13. Oral rehydration therapy for preoperative fluid and electrolyte management.

    Science.gov (United States)

    Taniguchi, Hideki; Sasaki, Toshio; Fujita, Hisae

    2011-01-01

    Preoperative fluid and electrolyte management is usually performed by intravenous therapy. We investigated the safety and effectiveness of oral rehydration therapy (ORT) for preoperative fluid and electrolyte management of surgical patients. The study consisted of two studies, designed as a prospective observational study. In a pilot study, 20 surgical patients consumed 1000 mL of an oral rehydration solution (ORS) until 2 h before induction of general anesthesia. Parameters such as serum electrolyte concentrations, fractional excretion of sodium (FENa) as an index of renal blood flow, volume of esophageal-pharyngeal fluid and gastric fluid (EPGF), and patient satisfaction with ORT were assessed. In a follow-up study to assess the safety of ORT, 1078 surgical patients, who consumed ORS until 2 h before induction of general anesthesia, were assessed. In the pilot study, water, electrolytes, and carbohydrate were effectively and safely supplied by ORT. The FENa value was increased at 2 h following ORT. The volume of EPGF collected following the induction of anesthesia was 5.3±5.6 mL. In the follow-up study, a small amount of vomiting occurred in one patient, and no aspiration occurred in the patients. These results suggest that ORT is a safe and effective therapy for the preoperative fluid and electrolyte management of selected surgical patients.

  14. Osmolality and electrolytes in cerebrospinal fluid and serum of febrile children with and without seizures.

    Science.gov (United States)

    Kiviranta, T; Tuomisto, L; Airaksinen, E M

    1996-02-01

    During acute febrile diseases mild disturbances of water and electrolyte balance occur frequently. It has been suggested that changes in electrolyte balance, in particular hyponatraemia, might predispose a child to convulsions during febrile illness; however, the changes of electrolytes in the CSF are not known. We have studied the effects of fever and convulsions on water and electrolyte balance in CSF and serum by measuring osmolality and electrolyte concentrations in children. The febrile population consisted of 60 children, 36 of whom had seizures during fever. Twenty-one children without convulsions and nine children with epileptic symptoms were nonfebrile controls. We noticed that CSF is subject to changes in osmolality and electrolyte concentration during fever, while convulsions do not exhibit such changes. CSF osmolality and sodium concentrations were lower in febrile children than in nonfebrile controls. The osmolality in febrile children with convulsions was 3.8% (P electrolyte balance. The alterations in CSF osmolality and sodium concentration do not, however, give an unambiguous explanation for the susceptibility to simple febrile seizures.

  15. Clinical evaluation of the Nanoduct sweat test system in the diagnosis of cystic fibrosis after newborn screening

    NARCIS (Netherlands)

    Vernooij-van Langen, Annette; Dompeling, Edward; Yntema, Jan-Bart; Arets, HGM|info:eu-repo/dai/nl/244205698; Tiddens, Harm; Loeber, Gerard; Dankert-Roelse, Jeannette

    After a positive newborn screening test for cystic fibrosis (CF), a sweat test is performed to confirm the diagnosis. The success rate of the generally acknowledged methods (Macroduct/Gibson and Cooke) in newborns varies between 73 and 99 %. The Nanoduct sweat test system is easier to perform and

  16. 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

  17. 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.

  18. 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

  19. Real-time sweat analysis: Concept and development of an autonomous wearable micro-fluidic platform

    OpenAIRE

    Curto, Vincenzo F.; Coyle, Shirley; Byrne, Robert; Diamond, Dermot; Benito-Lopez, Fernando

    2011-01-01

    In this work the development of an autonomous, robust and wearable micro-fluidic platform capable of performing on-line analysis of pH in sweat is discussed. Through the means of an optical detection system based on a surface mount light emitting diode (smLED) and a photodiode as a detector, a wearable system was achieved in which realtime monitoring of sweat pH can be performed during sport activity. We show how through systems engineering, integrating miniaturised electrical com...

  20. Hermetically Sealed Aluminum Electrolytic Capacitor

    Science.gov (United States)

    Alwitt, Robert S.; Liu, Yanming; Elias, William

    1996-01-01

    Aluminum electrolytic capacitors are presently not allowed on NASA missions because they outgas water and organic vapors, as well as H2. As a consequence, for some applications, much larger and heavier packages of tantalum capacitors must be used. A hermetically sealed aluminum capacitor has been developed. This contains a nongassing electrolyte that was developed for this application so internal pressure would remain low. Capacitors rated from 250 V to 540 V have been operated under full load for thousands of hours at 85 and 105 C with good electrical performance and absence of gas generation. Electrolyte chemistry and seal engineering will be discussed, as well as the extension of this design concept to lower voltage ratings.

  1. High elastic modulus polymer electrolytes

    Science.gov (United States)

    Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel

    2013-10-22

    A polymer that combines high ionic conductivity with the structural properties required for Li electrode stability is useful as a solid phase electrolyte for high energy density, high cycle life batteries that do not suffer from failures due to side reactions and dendrite growth on the Li electrodes, and other potential applications. The polymer electrolyte includes a linear block copolymer having a conductive linear polymer block with a molecular weight of at least 5000 Daltons, a structural linear polymer block with an elastic modulus in excess of 1.times.10.sup.7 Pa and an ionic conductivity of at least 1.times.10.sup.-5 Scm.sup.-1. The electrolyte is made under dry conditions to achieve the noted characteristics.

  2. Semiconductor electrolyte photovoltaic energy converter

    Science.gov (United States)

    Anderson, W. W.; Anderson, L. B.

    1975-01-01

    Feasibility and practicality of a solar cell consisting of a semiconductor surface in contact with an electrolyte are evaluated. Basic components and processes are detailed for photovoltaic energy conversion at the surface of an n-type semiconductor in contact with an electrolyte which is oxidizing to conduction band electrons. Characteristics of single crystal CdS, GaAs, CdSe, CdTe and thin film CdS in contact with aqueous and methanol based electrolytes are studied and open circuit voltages are measured from Mott-Schottky plots and open circuit photo voltages. Quantum efficiencies for short circuit photo currents of a CdS crystal and a 20 micrometer film are shown together with electrical and photovoltaic properties. Highest photon irradiances are observed with the GaAs cell.

  3. 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.

  4. Normal sweat secretion despite impaired growth hormone-insulin-like growth factor-I axis in obese subjects

    DEFF Research Database (Denmark)

    Rasmussen, M H; Juul, Anders; Main, Katharina M

    2011-01-01

    and after weight loss. Sixteen severely obese women (BMI, 40.6 ± 1.1 kg/m(2)) were investigated before and after a diet-induced weight loss. Sixteen age-matched nonobese women served as controls. The obese subjects presented the characteristic decreased GH release, hyperinsulinaemia, increased FFA levels......, 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......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...

  5. Solid-polymer-electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, T.F.

    1992-07-01

    A transport model for polymer electrolytes is presented, based on concentrated solution theory and irreversible thermodynamics. Thermodynamic driving forces are developed, transport properties are identified and experiments devised. Transport number of water in Nafion 117 membrane is determined using a concentration cell. It is 1.4 for a membrane equilibrated with saturated water vapor at 25{degrees}C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the water content approaches zero. The relation between transference number, transport number, and electroosmotic drag coefficient is presented, and their relevance to water-management is discussed. A mathematical model of transport in a solid-polymer-electrolyte fuel cell is presented. A two-dimensional membrane-electrode assembly is considered. Water management, thermal management, and utilization of fuel are examined in detail. The membrane separators of these fuel cells require sorbed water to maintain conductivity; therefore it is necessary to manage the water content in membranes to ensure efficient operation. Water and thermal management are interrelated. Rate of heat removal is shown to be a critical parameter in the operation of these fuel cells. Current-voltage curves are presented for operation on air and reformed methanol. Equations for convective diffusion to a rotating disk are solved numerically for a consolute point between the bulk concentration and the surface. A singular-perturbation expansion is presented for the condition where the bulk concentration is nearly equal to the consolute-point composition. Results are compared to Levich's solution and analysis.

  6. Solid-polymer-electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Thomas F. [Univ. of California, Berkeley, CA (United States)

    1992-07-01

    A transport model for polymer electrolytes is presented, based on concentrated solution theory and irreversible thermodynamics. Thermodynamic driving forces are developed, transport properties are identified and experiments devised. Transport number of water in Nafion 117 membrane is determined using a concentration cell. It is 1.4 for a membrane equilibrated with saturated water vapor at 25°C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the water content approaches zero. The relation between transference number, transport number, and electroosmotic drag coefficient is presented, and their relevance to water-management is discussed. A mathematical model of transport in a solid-polymer-electrolyte fuel cell is presented. A two-dimensional membrane-electrode assembly is considered. Water management, thermal management, and utilization of fuel are examined in detail. The membrane separators of these fuel cells require sorbed water to maintain conductivity; therefore it is necessary to manage the water content in membranes to ensure efficient operation. Water and thermal management are interrelated. Rate of heat removal is shown to be a critical parameter in the operation of these fuel cells. Current-voltage curves are presented for operation on air and reformed methanol. Equations for convective diffusion to a rotating disk are solved numerically for a consolute point between the bulk concentration and the surface. A singular-perturbation expansion is presented for the condition where the bulk concentration is nearly equal to the consolute-point composition. Results are compared to Levich`s solution and analysis.

  7. 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.

  8. Sauna, sweat and science - quantifying the proportion of condensation water versus sweat using a stable water isotope ((2)H/(1)H and (18)O/(16)O) tracer experiment.

    Science.gov (United States)

    Zech, Michael; Bösel, Stefanie; Tuthorn, Mario; Benesch, Marianne; Dubbert, Maren; Cuntz, Matthias; Glaser, Bruno

    2015-01-01

    Most visitors of a sauna appreciate the heat pulse that is perceived when water is poured on the stones of a sauna stove. However, probably only few bathers are aware that this pleasant heat pulse is caused by latent heat being released onto our skin due to condensation of water vapour. In order to quantify the proportion of condensation water versus sweat to dripping water of test persons we conducted sauna experiments using isotopically labelled (δ(18)O and δ(2)H) thrown water as tracer. This allows differentiating between 'pure sweat' and 'condensation water'. Two ways of isotope mass balance calculations were applied and yielded similar results for both water isotopes. Accordingly, condensation contributed considerably to dripping water with mean proportions of 52 ± 12 and 54 ± 7% in a sauna experiment in winter semester 2011/12 and 30 ± 13 and 33 ± 6% in a sauna experiment in winter semester 2012/13, respectively, depending on the way of calculating the isotope mass balance. It can be concluded from the results of our dual isotope labelling sauna experiment that it is not all about sweat in the sauna.

  9. Store-operated Ca2+ entry regulates Ca2+-activated chloride channels and eccrine sweat gland function.

    Science.gov (United States)

    Concepcion, Axel R; Vaeth, Martin; Wagner, Larry E; Eckstein, Miriam; Hecht, Lee; Yang, Jun; Crottes, David; Seidl, Maximilian; Shin, Hyosup P; Weidinger, Carl; Cameron, Scott; Turvey, Stuart E; Issekutz, Thomas; Meyts, Isabelle; Lacruz, Rodrigo S; Cuk, Mario; Yule, David I; Feske, Stefan

    2016-11-01

    Eccrine sweat glands are essential for sweating and thermoregulation in humans. Loss-of-function mutations in the Ca2+ release-activated Ca2+ (CRAC) channel genes ORAI1 and STIM1 abolish store-operated Ca2+ entry (SOCE), and patients with these CRAC channel mutations suffer from anhidrosis and hyperthermia at high ambient temperatures. Here we have shown that CRAC channel-deficient patients and mice with ectodermal tissue-specific deletion of Orai1 (Orai1K14Cre) or Stim1 and Stim2 (Stim1/2K14Cre) failed to sweat despite normal sweat gland development. SOCE was absent in agonist-stimulated sweat glands from Orai1K14Cre and Stim1/2K14Cre mice and human sweat gland cells lacking ORAI1 or STIM1 expression. In Orai1K14Cre mice, abolishment of SOCE was associated with impaired chloride secretion by primary murine sweat glands. In human sweat gland cells, SOCE mediated by ORAI1 was necessary for agonist-induced chloride secretion and activation of the Ca2+-activated chloride channel (CaCC) anoctamin 1 (ANO1, also known as TMEM16A). By contrast, expression of TMEM16A, the water channel aquaporin 5 (AQP5), and other regulators of sweat gland function was normal in the absence of SOCE. Our findings demonstrate that Ca2+ influx via store-operated CRAC channels is essential for CaCC activation, chloride secretion, and sweat production in humans and mice.

  10. A novel TMEM16A splice variant lacking the dimerization domain contributes to calcium-activated chloride secretion in human sweat gland epithelial cells.

    Science.gov (United States)

    Ertongur-Fauth, Torsten; Hochheimer, Andreas; Buescher, Joerg Martin; Rapprich, Stefan; Krohn, Michael

    2014-11-01

    Sweating is an important physiological process to regulate body temperature in humans, and various disorders are associated with dysregulated sweat formation. Primary sweat secretion in human eccrine sweat glands involves Ca(2+) -activated Cl(-) channels (CaCC). Recently, members of the TMEM16 family were identified as CaCCs in various secretory epithelia; however, their molecular identity in sweat glands remained elusive. Here, we investigated the function of TMEM16A in sweat glands. Gene expression analysis revealed that TMEM16A is expressed in human NCL-SG3 sweat gland cells as well as in isolated human eccrine sweat gland biopsy samples. Sweat gland cells express several previously described TMEM16A splice variants, as well as one novel splice variant, TMEM16A(acΔe3) lacking the TMEM16A-dimerization domain. Chloride flux assays using halide-sensitive YFP revealed that TMEM16A is functionally involved in Ca(2+) -dependent Cl(-) secretion in NCL-SG3 cells. Recombinant expression in NCL-SG3 cells showed that TMEM16A(acΔe3) is forming a functional CaCC, with basal and Ca(2+) -activated Cl(-) permeability distinct from canonical TMEM16A(ac). Our results suggest that various TMEM16A isoforms contribute to sweat gland-specific Cl(-) secretion providing opportunities to develop sweat gland-specific therapeutics for treatment of sweating disorders. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Efficient Electrolytes for Lithium–Sulfur Batteries

    OpenAIRE

    Natarajan eAngulakshmi; Arul Manuel Stephan

    2015-01-01

    This review article mainly encompasses on the state-of-the-art electrolytes for lithium–sulfur batteries. Different strategies have been employed to address the issues of lithium–sulfur batteries across the world. One among them is identification of electrolytes and optimization of their properties for the applications in lithium–sulfur batteries. The electrolytes for lithium–sulfur batteries are broadly classified as (i) non-aqueous liquid electrolytes, (ii) ionic liquids, (iii) solid polyme...

  12. Polymer Electrolytes for Lithium/Sulfur Batteries

    OpenAIRE

    The Nam Long Doan; Denise Gosselink; Yongguang Zhang; Mikhail Sadhu; Ho-Jae Cheang; Pu Chen; Yan Zhao

    2012-01-01

    This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S) batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes.

  13. Polymer Electrolytes for Lithium/Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    The Nam Long Doan

    2012-08-01

    Full Text Available This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes.

  14. Polymer Electrolytes for Lithium/Sulfur Batteries

    Science.gov (United States)

    Zhao, Yan; Zhang, Yongguang; Gosselink, Denise; Doan, The Nam Long; Sadhu, Mikhail; Cheang, Ho-Jae; Chen, Pu

    2012-01-01

    This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S) batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes. PMID:24958296

  15. Fluid and electrolyte balance during two different preseason training sessions in elite rugby union players.

    Science.gov (United States)

    Cosgrove, Samuel D; Love, Thomas D; Brown, Rachel C; Baker, Dane F; Howe, Anna S; Black, Katherine E

    2014-02-01

    The purpose of this study was to compare fluid balance between a resistance and an aerobic training sessions, in elite rugby players. It is hypothesized that resistance exercise will result in a higher prevalence of overdrinking, whereas during the aerobic session, underdrinking will be more prevalent. As with previous fluid balance studies, this was an observational study. Twenty-six players completed the resistance training session, and 20 players completed the aerobic training session. All players were members of an elite rugby union squad competing in the southern hemisphere's premier competition. For both sessions, players provided a preexercise urine sample to determine hydration status, pre- and postexercise measures of body mass, and blood sodium concentration were taken, and the weight of drink bottles were recorded to calculate sweat rates and fluid intake rates. Sweat patches were positioned on the shoulder of the players, and these remained in place throughout each training session and were later analyzed for sodium concentration. The percentage of sweat loss replaced was higher in the resistance (196 ± 130%) than the aerobic training session (56 ± 17%; p = 0.002). Despite this, no cases of hyponatremia were detected. The results also indicated that more than 80% of players started training in a hypohydrated state. Fluid intake seems to differ depending on the nature of the exercise session. In this group of athletes, players did not match their fluid intakes with their sweat loss, resulting in overdrinking during resistance training and underdrinking in aerobic training. Therefore, hydration strategies and education need to be tailored to the exercise session. Furthermore, given the large number of players arriving at training hypohydrated, improved hydration strategies away from the training venue are required.

  16. Cantera and Cantera Electrolyte Thermodynamics Objects

    Energy Technology Data Exchange (ETDEWEB)

    2015-10-19

    Cantera is a suite of object-oriented software tools for problems involving chemical kinetics, thermodynamics, and/or transport processes. It is a multi-organizational effort to create and formulate high quality 0D and 1D constitutive modeling tools for reactive transport codes.Institutions involved with the effort include Sandia, MIT, Colorado School of Mines, U. Texas, NASA, and Oak Ridge National Labs. Specific to Sandia's contributions, the Cantera Electrolyte Thermo Objects (CETO) packages is comprised of add-on routines for Cantera that handle electrolyte thermochemistry and reactions within the overall Cantera package. Cantera is a C++ Cal Tech code that handles gas phase species transport, reaction, and thermodynamics. With this addition, Cantera can be extended to handle problems involving liquid phase reactions and transport in electrolyte systems, and phase equilibrium problemsinvolving concentrated electrolytes and gas/solid phases. A full treatment of molten salt thermodynamics and transport has also been implemented in CETO. The routines themselves consist of .cpp and .h files containing C++ objects that are derived from parent Cantera objects representing thermodynamic functions. They are linked unto the main Cantera libraries when requested by the user. As an addendum to the main thermodynamics objects, several utility applications are provided. The first is multiphase Gibbs free energy minimizer based on the vcs algorithm, called vcs_cantera. This code allows for the calculation of thermodynamic equilibrium in multiple phases at constant temperature and pressure. Note, a similar code capability exists already in Cantera. This version follows the same algorithm, but gas a different code-base starting point, and is used as a research tool for algorithm development. The second program, cttables, prints out tables of thermodynamic and kinetic information for thermodynamic and kinetic objects within Cantera. This program serves as a "Get the

  17. Roles of Electrolyte Characterization on Bauxite Electrolysis Desulfurization with Regeneration and Recycling

    Science.gov (United States)

    Gong, Xuzhong; Wang, Zhi; Zhuang, Siyuan; Wang, Dong; Wang, Yuhua; Wang, Mingyong

    2017-02-01

    The recycling of NaCl used as supporting electrolyte for bauxite electrolysis was carried out in this study. The electrolyte was regenerated by adding anhydrous CaCl2 into the solution after filtration, and effects of electrolyte characterization on bauxite electrolysis were examined by observing the change in desulfurization ratio and cell voltage. The results indicated that the desulfurization ratio increased with increasing recycling times of electrolyte. In the meantime, the increase in recycling times has led to the decrease in pH value as well as the increase in Fe ion concentration in the electrolyte, which were the main reasons for the increase in the desulfurization ratio with increasing recycling of electrolyte. The pH value of electrolyte after second electrolysis was lower than 1.5, and the desulfurization ratio increased obviously due to the increase in Fe3+ concentration and suppression of jarosite formation. The increase in Ca2+ concentration did not apparently change desulfurization ratio and anode surface activity. However, with Ca2+ addition, the cathode surface was covered by CaSO4·nH2O, thus resulting in the increase of cell voltage.

  18. Rechargeable solid polymer electrolyte battery cell

    Science.gov (United States)

    Skotheim, Terji

    1985-01-01

    A rechargeable battery cell comprising first and second electrodes sandwiching a solid polymer electrolyte comprising a layer of a polymer blend of a highly conductive polymer and a solid polymer electrolyte adjacent said polymer blend and a layer of dry solid polymer electrolyte adjacent said layer of polymer blend and said second electrode.

  19. Skin irritation testing of antimicrobial conjugated electrolytes.

    Science.gov (United States)

    Wilde, Kristin N; Nguyen, Phuong A H; Whitten, David G; Canavan, Heather E

    2017-04-20

    Each year, the United States spends about $20 billion to treat people who have been infected with antibiotic resistant bacteria. Even so, the development of new antibiotics has slowed considerably since the mid-20th century. As a result, researchers are looking into developing synthetic compounds and materials with antimicrobial activities such as those made by the Schanze and Whitten groups [ACS Appl. Mater. Interfaces 3, 2820 (2011)]. Previously, they have demonstrated that poly(phenylene ethynylene) (PPE) based electrolytes and oligomeric end-only phenylene ethynylene (EO-OPE) based electrolytes possess strong biocidal activity. However, before the PPE and OPE can be used with humans, skin irritation tests are required to ensure their safety. In this work, in vitro skin assays are used to predict in vivo irritation. Tissues were conditioned for 24 h, exposed to test substances for 1 h, and then tested for viability using colorimetric and cytokine assays. Concentrations up to 50 μg/ml were tested. Viability assays and cytokine (IL-1α) assays demonstrated that the two polymers, three symmetric oligomers, and three "end only" oligomers were nonirritants. In addition, electrospun mats consisting of several promising compounds, including poly(caprolactone), were evaluated. Therefore, all test substances are conservatively classified as nonirritants after a 1 h exposure time period.

  20. Optimization of non-aqueous electrolytes for Primary lithium/air batteries operated in Ambient Enviroment

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wu; Xiao, Jie; Zhang, Jian; Wang, Deyu; Zhang, Jiguang

    2009-07-07

    The selection and optimization of non-aqueous electrolytes for ambient operations of lithium/air batteries has been studied. Organic solvents with low volatility and low moisture absorption are necessary to minimize the change of electrolyte compositions and the reaction between lithium anode and water during discharge process. It is critical to make the electrolytes with high polarity so that it can reduce wetting and flooding of carbon based air electrode and lead to improved battery performance. For ambient operations, the viscosity, ionic conductivity, and oxygen solubility of the electrolyte are less important than the polarity of organic solvents once the electrolyte has reasonable viscosity, conductivity, and oxygen solubility. It has been found that PC/EC mixture is the best solvent system and LiTFSI is the most feasible salt for ambient operations of Li/air batteries. Battery performance is not very sensitive to PC/EC ratio or salt concentration.