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1

Molecular Structure of Phenolphthalein  

NSDL National Science Digital Library

Phenolphthalein was first made in 1880. The compound is a good pH indicator because it turns red in a solution with a pH above 8. Phenolphthalein can also be used as a laxative. When used for therapeutic purposes it can cause hypersensitivity. Phenolphthalein also colors urine and other bodily excretions a pink or red color when it is present in the body.

2002-08-13

2

Plasticized phenolphthalein polycarbonate  

NASA Technical Reports Server (NTRS)

Phenolphthalein polycarbonate was successfully plasticized with polychlorinated biphenyls (e.g., Aroclor 1231) or tricresyl phosphate and cast from tetrahydrofuran to give clear films without loss of fire resistance. At loadings of 20 to 30 percent plasticizer the Tg was lowered to approximately 100 C which would render phenolphthalein polycarbonate easily moldable. Although these materials had some mechanical integrity as shown by their film forming ability, the room temperature toughness of the plasticized polymer was not significantly improved over unmodified polymer.

Harrison, E. S.

1976-01-01

3

FAILURE OF PHENOBARBITAL TO INDUCE RAT HEPATIC MICROSOMAL UDP-GLUCURONYLTRANSFERASE TOWARD PHENOLPHTHALEIN  

EPA Science Inventory

Phenobarbital pretreatment was found not to induce Triton X-100 activated hepatic microsomal neonatal UDP-glucuronyltransferase activity towards phenolphthalein in male, female and pregnant female rats....

4

Laser Light-Scattering Study of Novel Thermoplastics. 2. Phenolphthalein Poly(ether sulfone) (PES-C)  

Microsoft Academic Search

Five narrowly distributed fractions of phenolphthalein poly(ether sulfone) (PES-C) were studied in CHCl3 by both static and dynamic laser light scattering (LLS) at 25 °C. The dynamic LLS showed that the PES-C samples contain some large polymer clusters as in previously studied phenolphthalein poly(ether ketone) (PEK-C). These large clusters can be removed by a 0.1-Ìm filter. Our results showed that

Chi Wu; Mohammad Siddiq; Shuqin Bo; Tianlu Chen

1996-01-01

5

Laser Light-Scattering Study of Novel Thermoplastics. 1. Phenolphthalein Poly(aryl ether ketone)  

Microsoft Academic Search

Five different molecular weight phenolphthalein poly(aryl ether ketone) (PEK-C) fractions in CHCl3 were studied by static and dynamic laser light scattering (LLS). The dynamic LLS revealed that the PEK-C samples contain some large polymer clusters. These large clusters can be removed by filtering the solution with a 0.1-Ìm filter. We found that the persistence length of PEK-C in CHCl3 at

Chi Wu; Shuqin Bo; Mohammad Siddiq; Guojun Yang; Tianlu Chen

1996-01-01

6

Synthesis of optically clear polymeric materials for high temperature windows. [preparation of phenolphthalein polycarbonate resin  

NASA Technical Reports Server (NTRS)

A polymer has been developed that has excellent potential for use as windows in spacecraft as well as conventional aircraft. This polymer, phenolphthalein polycarbonate, has outstanding thermal properties, e.g., in place of melting or burning, it produces an insulating charred foam that closes off transmission of radiant heat through the window. This fact, coupled with an oxygen index of 0.43 and a 177 C tensile strength of 58 mega Newtons/sq m, makes this polymer a prime candidate for further development. Pilot plant preparation in a 20 gallon Pfaudler kettle was accomplished and large test specimens were prepared for evaluations.

Pannell, C. E.; Magner, J. E.

1973-01-01

7

End group functionalization of poly(ethylene glycol) with phenolphthalein: towards star-shaped polymers based on supramolecular interactions  

PubMed Central

Summary The synthesis of a new phenolphthalein azide derivative, which can be easily utilized in polymer analogous reactions, is presented. The subsequent cycloaddition reaction with propargyl-functionalized methoxypoly(ethylene glycol) yielded polymers bearing phenolphthalein as the covalently attached end group. In presence of per-?-cyclodextrin-dipentaerythritol, the formation of stable inclusion complexes was observed, representing an interesting approach towards the formation of star shaped polymers. The decolorization of a basic polymer solution caused by the complexation was of great advantage since this behavior enabled following the complex formation by UV–vis spectroscopy and even the naked eye. PMID:25298793

Fleischmann, Carolin; Wöhlk, Hendrik

2014-01-01

8

Evaluation of phenolphthalein, diazepam and quinacrine dihydrochloride in the in vitro mammalian cell micronucleus test in Chinese hamster ovary (CHO) and TK6 cells.  

PubMed

The in vitro micronucleus assay has been extensively used as an in vitro screening tool to identify test articles that might have aneugenic or clastogenic potential. Currently, the Organization for Economic Co-operation and Development (OECD) is working towards a final version of the guideline for the conduct of the in vitro mammalian cell micronucleus Test (MNvit). A few questions regarding appropriate cytotoxicity measurements and cytotoxicity limits to use remain to be answered. In order to resolve the remaining questions, we compared the induction of micronuclei at the top dose (50-60% cytotoxicity) determined by either Relative Cell Counts (RCC), Relative Increase in Cell Counts (RICC), Relative Population Doublings (RPD), or Cytokinesis-Blocked Proliferating Index (CBPI) using weak and strong inducers of micronuclei in both the presence and absence of cytochalasin B (CYB) in Chinese hamster ovary (CHO) and human lymphoblastoid TK6 cells. In order to assess extensive dose-response relationships, we selected expected weak (diazepam, phenolphthalein, quinacrine dihydrochloride dihydrate) and strong (cytosine arabinoside, mitomycin C, vinblastine sulphate) inducers of micronuclei with a variety of different mechanisms of action for testing. The results clearly demonstrated that all six compounds produced positive responses using either cytotoxicity measurement. The outcome from these studies further supports the cytotoxicity measurements and cytotoxicity limits proposed in the draft OECD guideline. PMID:20399283

Schuler, Maik; Gudi, Ramadevi; Cheung, Jennifer; Kumar, Shyam; Dickinson, Donna; Engel, Maria; Szkudlinska, Anna; Colman, Megan; Maduka, Nkechi; Sherman, Jocelyn; Thiffeault, Catherine

2010-10-29

9

Phenolphthalein-Pink Tornado Demonstration  

ERIC Educational Resources Information Center

The titration of HCl with NaOH has traditionally been used to introduce beginning chemistry students to the concepts of acid-base chemistry and stoichiometry. The demonstration described in this article utilizes this reaction as a means of providing students an opportunity to observe the dynamic motion associated with a swirling vortex and its…

Prall, Bruce R.

2008-01-01

10

Determination of Binding Constants by Flow Injection Gradient Technique  

E-print Network

for the determination of binding constants of substrates with cyclodextrins or micelles. The concentration gradient of inclusion complex formation between -cyclodextrin ( -CD) and phenolphthalein and of the incorporation

Reid, Scott A.

11

Diarrhea, Red Diapers, and Child AbuseClinical Alertness Needed for Recognition; Clinical Skill Needed for Success in Management  

Microsoft Academic Search

Three children were chronically given phenolphthalein in the form of laxatives by emotionally disturbed mothers. All children had repeated hos pitalizations and extensive diagnostic testing because of recurrent intractable unexplained diarrhea. One child died. Pink-red urine and stool were passed at some time during their illnesses. The presence of phenolphthalein was tested for by application of dilute acid or dilute

David Fleisher; Marvin E. Ament

1977-01-01

12

The Best Enzyme Investigation Ever? Probably.  

ERIC Educational Resources Information Center

Uses alkaline phosphate to remove the phosphate group from phenolphthalein diphosphate. Discusses problems which include the interference of ambient light and temperature variation. Provides detailed information about the apparatus and the experimental procedure. (ASK)

Cooper, Phil

2000-01-01

13

The Production of Active Nitrogen in the Soil.  

E-print Network

the filtrate with stan- dard sodium hydroxide. As pointed out by Veitch, this acidity depends upon the reaction between the soil and the sodium chloride by which iron and aluminum chlorides are formed, these compouods being acid to phenolphthalein. Only... with caustic soda and phenolphthalein. Since salts of iron and aluminum are acid to this indicator and the corresponding hydroxides are precipitated during the ti- tration, this method does not include the basicity due to bases of iron and aluminum...

Fraps, G. S. (George Stronach)

1908-01-01

14

27 CFR 21.102 - Caustic soda, liquid.  

Code of Federal Regulations, 2011 CFR

...with distilled water at room temperature. Transfer a 25 ml aliquot of the solution to a titration flask, add 10 ml of 1 percent barium chloride solution, 0.2 ml of 1 percent phenolphthalein indicator, and 50 ml of distilled water. Titrate with...

2011-04-01

15

27 CFR 21.102 - Caustic soda, liquid.  

...with distilled water at room temperature. Transfer a 25 ml aliquot of the solution to a titration flask, add 10 ml of 1 percent barium chloride solution, 0.2 ml of 1 percent phenolphthalein indicator, and 50 ml of distilled water. Titrate with...

2014-04-01

16

ch11pr Page 1 of 14 http://www.jbpub.com/fox/supplementalproblems/ch11pr.htm 11/18/2003  

E-print Network

activate anhydrides to Friedel-Crafts reactions, especially with strong para directing groups of the second Friedel Crafts reaction can undergo dehydration to give the oxidized form of phenolphthalein intact while it is the alkyl group which is changing position. Also, the product would seem to be driven

Walba, David

17

Overhead Projector Demonstrations.  

ERIC Educational Resources Information Center

Described are three chemistry demonstrations: (1) a simple qualitative technique for taste pattern recognition in structure-activity relationships; (2) a microscale study of gaseous diffusion using bleach, HCl, ammonia, and phenolphthalein; and (3) the rotation of polarized light by stereoisomers of limonene. (MVL)

Kolb, Doris, Ed.

1989-01-01

18

Initial evaluation tests of General Electric Company 12.0 ampere hour nickel cadmium spacecraft cells with design variables  

NASA Technical Reports Server (NTRS)

All evaluation tests were performed at room ambient pressure and temperature, with discharges at a 2 hour rate. Tests consisted of phenolphthalein leak tests, three capacity tests, an auxiliary electrode test, a charge retention test, an internal short test, a charge efficiency test, overcharge tests, and a pressure versus capacity test. Results of the tests and recommendations for improvements in manufacturing are presented.

Harkness, J. D.

1979-01-01

19

Synthetic and analytical studies on colour reagents-IX The reactions of phthaleinazo compounds with the alkaline earths.  

PubMed

Some new phthaleinazo compounds-o,o'-dihydroxyazo compounds-have been prepared by coupling chromotropic acid, R-acid, and 2-hydroxy-3-naphthoic acid with bis-diazotized diaminophthaleins. These compounds have been found to be very sensitive colour reagents for alkaline earths in alkaline media, and in particular, bis(chromotropeazo)phenolphthalein is the most sensitive yet found. PMID:18960139

Kobatake, T; Iwachido, T; Tôei, K

1967-05-01

20

Molecular Models of Indicators  

NSDL National Science Digital Library

The article by Nicholas C. Thomas and Stephen Faulk on "Colorful Chemical Fountains" (1) reminds us that color—the colors of acid–base indicators or of metal complexes—is responsible for many of us developing an interest in chemistry. The featured molecules this month are the acid and base forms of three common indicators–phenolphthalein, methyl orange, and methyl red. These three substances display interesting structural features as the pH-induced transformation from one form to another takes place in three different ways. In the case of phenolphthalein, the lactam ring is cleaved on deprotonation to produce a carboxyl group with the concomitant removal of a proton from a phenolic group. In methyl orange, one of the nitrogen atoms is protonated in the acid form, and that proton is lost in the base form. In methyl red, a carboxylic acid function is deprotonated. There are many other interesting aspects of acid–base indicators. Since most plants and fruits contain pigments that show a color change in some pH range, it is difficult to state with any degree of certainty when these changes were first put to use in a systematic fashion. The Spanish alchemist Arnaldus de Villa Nova (Arnold of Villanova) is purported to have used litmus in the early 14th century. In general systematic use of indicators is traced to the latter half of the nineteenth century with the development of the three synthetic indicators described above. Many students will be familiar with the use of phenolphthalein to identify blood—often shown on the various forensic chemistry TV dramas by dropping some solution on a cotton swab that has been used to pick up some of the sample in question. If the swab turns red we frequently hear "It's blood". The reality of using phenolphthalein in this way is more complicated. The test is presumptive for the presence of blood, but not conclusive. It is not an acid–base reaction but rather, in the presence of hydrogen peroxide, relies on hemoglobin to catalyze the oxidation of phenolphthalein. An interesting assignment for students in a high-school or non-majors course would be to have them explore the details of this Kastle–Meyers test to see just what is involved in the correct application of the test, and what factors complicate the process. For example, would tomato juice infused with asparagus juice give a positive Kastle–Meyers test? Historically phenolphthalein was used in a variety of laxatives. Recently that usage has been discontinued due to concern about the carcinogenic nature of the substance. A review of the history of the controversy surrounding the use of phenolphthalein in laxatives would make a good research paper at the high-school level. Lastly, students with some practice building structures and performing calculations might wish to explore the structures of two other forms of phenolphthalein—one found in very acidic solutions, having an orange color, and one found in very basic solutions that is colorless.

21

LABORATORY EXPERIMENT 3 Alkalimetric Titration of an Acid  

E-print Network

of carbonate- free 0.1 M NaOH. Boil approximately 1 L of deionized water and cool it to room temperature. Add samples (to the nearest 0.0001 g) and dissolve in around 50 mL of water. Add 2-3 drops of phenolphthalein.07). Weigh individual 0.2 g samples (to the nearest 0.0001 g) and dissolve in around 50 mL of water. Add 2

Nazarenko, Alexander

22

RELATIVE IRRITANT PROPERTIES OF THE CHLORINE GROUP OF ANTISEPTICS  

PubMed Central

1. The use of the ears of rabbits is proposed in testing the irritant effect of antiseptics. 2. It is necessary, because of individual variations, to use solutions having definite irritant actions as controls. 3. 0.5 per cent sodium hypochlorite solutions have minimum irritant effects over a range of alkalinity of from about 100 to 1,000 times that of water (pH about 9 to 10). Solutions may be adjusted within these limits by use of the end-points of powdered phenolphthalein, of alcoholic solutions of either o-cresolphthalein or phenolphthalein. 4. Sodium hypochlorite solutions kept within the above range of alkalinity by either borate or carbonate buffer salts, i.e. Dakin's solution, show the same irritative properties whether made from bleaching powder and sodium carbonate, or from chlorine and sodium carbonate. 5. Electrolytically prepared solutions of the same concentration have similar irritant action. 6. Solutions, however, that have an alkalinity less than that indicated by the end-point of alcoholic phenolphthalein solutions (pH of 8.5 to 8.8) or greater than that indicated by the end-point to powdered phenolphthalein (pH of 10.2) are intensely irritating. 7. 0.5 per cent sodium hypochlorite solution from which most of the calcium has been precipitated and calcium hypochlorite solution of equivalent hypochlorite concentration are only slightly irritating. 8. 2 per cent chloramine-T solution has no irritant action. 9. 5 per cent dichloramine-T in chlorcosane and chlorcosane alone irritate rabbit ears to a slight degree only. PMID:19868288

Cullen, Glenn E.; Taylor, Herbert D.

1918-01-01

23

Active pharmaceutical ingredients detected in herbal food supplements for weight loss sampled on the Dutch market.  

PubMed

Herbal food supplements claiming to reduce weight may contain active pharmacological ingredients (APIs) that can be used for the treatment of overweight and obesity. The aim of this study was to determine whether herbal food supplements for weight loss on the Dutch market contain APIs with weight loss properties. Herbal food supplements intended for weight loss (n = 50) were sampled from August 2004 to May 2013. An HPLC-DAD-MS/MS method was used to screen for the presence of the APIs in herbal supplements. In 24 samples the APIs sibutramine, desmethylsibutramine (DMS), didesmethylsibutramine (DDMS), rimonabant, sildenafil and/or the laxative phenolphthalein were identified 41 times. The presence of these APIs was, however, not stated on the label. The potential pharmacological effects of the detected APIs were estimated using data from reported effective doses of approved drugs. Use of 20 of the 24 herbal food supplements may result in potential pharmacological effects. Furthermore, risk assessment of phenolphthalein, a suspected carcinogen and found to be present in 10 supplements, based on the margin of exposure (MOE) approach, resulted in MOE values of 96-30 000. MOE values lower than 10 000 (96-220) were calculated for the daily intake levels of four out of these 10 supplements in which phenolphthalein was found. However, taking into account that weight loss preparations may be used for only a few weeks or months rather than during a lifetime, MOE values may be two to three orders of magnitude higher. The current study shows that the use of food supplements with sibutramine, DMS, DDMS and/or phenolphthalein could result in pharmacological effects. PMID:25247833

Reeuwijk, Noortje M; Venhuis, Bastiaan J; de Kaste, Dries; Hoogenboom, Ron L A P; Rietjens, Ivonne M C M; Martena, Martijn J

2014-11-01

24

Invisible Ink Demonstration  

NSDL National Science Digital Library

In this chemistry demonstration, learners will discover that phenolphthalein is a chemical that displays different colors depending on the acidity or basicity of the environment. Learners will be surprised to see a "secret message" appear in bright pink ink when it is sprayed with Windex containing ammonia (a base). They compare this to what happens when the message is sprayed with Windex containing acetic acid (nothing!).

House, The S.

2014-01-28

25

Evaluation of diamine oxidase activity (DAO) in the rat intestinal mucosa by measuring expired 14 CO 2 after oral administration of 14 C-putrescine  

Microsoft Academic Search

This study was performed to investigate whether mucosal diamine oxidase activity could be assessed by measuring expired14CO2 after oral administration of14C-putrescine. Immediately after giving 5 µCi of14C-putrescine, the14CO2 was collected at 1-h intervals for 8 h into a vial containing 1 ml of 10 mM hyamine hydroxide, 2 ml of ethanol, and an appropriate amount of phenolphthalein dye. The expired14CO2

Tadao Bamba; Akira Sasaki; Shiro Hosoda

1994-01-01

26

Witches' Potion Demonstration  

NSDL National Science Digital Library

In this chemistry demonstration, learners will discover that phenolphthalein is an acid/base indicator. One learner will read a poem about four witches making a potion. Four learners will act out the parts, adding chemicals and water to different beakers (with adult supervision). Learners will enjoy the poem as the indicators react with the substances and change color. This is a fun chemistry demonstration to use during Halloween.

The Science House

2014-01-28

27

Determination of free fatty acids in palm oil samples using non-aqueous flow injection titrimetric method  

Microsoft Academic Search

Flow injection (FI) non-aqueous titrimetric methods for the determination of free fatty acids (FFA) in palm oil samples are described. Single-line and two-line FI manifolds using phenolphthalein (PHP) and bromothymol blue (BTB) as indicators were developed. The method is based on the monitoring of the changes of absorbance of the indicators used from basic–acidic–basic form (pink–colourless–pink for PHP, blue–yellow–blue for

Bahruddin Saad; Cheng Woon Ling; Boey Peng Lim; Abdussalam Salhin Mohamad Ali; Wan Tatt Wai; Muhammad Idiris Saleh

2007-01-01

28

Inorganic polymers (geopolymers) containing acid–base indicators as possible colour-change humidity indicators  

Microsoft Academic Search

The alkalinity of aluminosilicate inorganic polymers (geopolymers) was found to change reversibly with humidity, suggesting the possibility of incorporating acid–base indicators to produce colour-change humidity indicators. Of the triphenylmethane indicators bromothymol blue, thymol blue, bromocresol green, phenolphthalein and thymolphthalein, and the azo-dye methyl red, only thymol blue showed a promising colour change from light tan (dry) to deep blue (dry)

K. J. D. MacKenzie; B. O'Leary

2009-01-01

29

Analysis of six synthetic adulterants in herbal weight-reducing dietary supplements by LC electrospray ionization-MS.  

PubMed

A liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method was developed for the simultaneous determination of six synthetic adulterants, namely fenfluramine, phenolphthalein, N-di-desmethyl sibutramine, N-mono-desmethyl sibutramine, sibutramine, and orlistat. The method was applied to the analysis of herbal weight-reducing dietary supplements. Chromatographic separation of the analytes on a C(8) reversed-phase column was achieved using a gradient elution of solvent A: acetonitrile and solvent B: aqueous 20 mM ammonium formate solution. Sildenafil was utilized as an internal standard for quantification. The MS detector was operated in positive electrospray ionization mode. Selected-ion monitoring (SIM) was carried out for m/z 232, 319, 252, 266, 280, 496, and 475 for fenfluramine, phenolphthalein, N-di-desmethyl sibutramine, N-mono-desmethyl sibutramine, sibutramine, orlistat, and sildenafil, respectively. The method was validated for accuracy, precision, linearity, and selectivity. The limits of detection for the six synthetic adulterants ranged from 0.0018 to 0.73 microg g(-1). The proposed method was used for a small survey of 22 dietary supplements of which eleven samples were adulterated with phenolphthalein, N-mono-desmethyl sibutramine, and sibutramine at levels from 0.212 to 96.2 mg g(-1). PMID:18569001

Wang, J; Chen, B; Yao, S

2008-07-01

30

Acid-base titrations using microfluidic paper-based analytical devices.  

PubMed

Rapid and simple acid-base titration was accomplished using a novel microfluidic paper-based analytical device (?PAD). The ?PAD was fabricated by wax printing and consisted of ten reservoirs for reaction and detection. The reaction reservoirs contained various amounts of a primary standard substance, potassium hydrogen phthalate (KHPth), whereas a constant amount of phenolphthalein was added to all the detection reservoirs. A sample solution containing NaOH was dropped onto the center of the ?PAD and was allowed to spread to the reaction reservoirs where the KHPth neutralized it. When the amount of NaOH exceeded that of the KHPth in the reaction reservoirs, unneutralized hydroxide ion penetrated the detection reservoirs, resulting in a color reaction from the phenolphthalein. Therefore, the number of the detection reservoirs with no color change determined the concentration of the NaOH in the sample solution. The titration was completed within 1 min by visually determining the end point, which required neither instrumentation nor software. The volumes of the KHPth and phenolphthalein solutions added to the corresponding reservoirs were optimized to obtain reproducible and accurate results for the concentration of NaOH. The ?PADs determined the concentration of NaOH at orders of magnitude ranging from 0.01 to 1 M. An acid sample, HCl, was also determined using Na2CO3 as a primary standard substance instead of KHPth. Furthermore, the ?PAD was applicable to the titrations of nitric acid, sulfuric acid, acetic acid, and ammonia solutions. The ?PADs were stable for more than 1 month when stored in darkness at room temperature, although this was reduced to only 5 days under daylight conditions. The analysis of acidic hot spring water was also demonstrated in the field using the ?PAD, and the results agreed well with those obtained by classic acid-base titration. PMID:25423320

Karita, Shingo; Kaneta, Takashi

2014-12-16

31

Ammonia (GCMP)  

NSDL National Science Digital Library

Ammonia fountain: this is a resource in the collection "General Chemistry Multimedia Problems". In an ammonia fountain, a flask is filled with ammonia gas. A tube from the flask extends into a pan of water that contains phenolphthalein. When a rubber bulb full of water is squeezed, the water squirts into the flask. Water from the pan then is pushed into the flask and the indicator changes color. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

32

Citrus bioactive compounds influencing phase II detoxifying enzymes: potential for cancer chemoprevention  

E-print Network

). Glucaric acid is an end metabolite of the D- glucuronic acid pathway metabolism in mammals (Marsh, 1963). The product of the oxidation of D-glucuronic acid yields glucaric acid (GA), D-glucaro-1,4-lactone (1,4- GL) and D-glucaro-6,3-lactone (6,3-GL... responsible for the inhibition of #1;-glucuronidase was saccharo-1,4-lactone (1,4-GL). 1,4- GL was found to be a very powerful inhibitor of #1;-glucuronidase having an affinity 240 times greater than that of phenolphthalein glucuronide, a substrate...

Perez, Jose Luis

2009-05-15

33

Development and the Educational Effect of a System of the Corrosion of Iron and the Anti-corrosion Ability of Conductive Polymer Polyaniline  

NASA Astrophysics Data System (ADS)

Few general chemistry textbooks of high schools, colleges and universities introduce the corrosion of iron into the oxidation-reduction (redox) section, although the corrosion is very popular phenomena for students. Besides, no description appears about conductive polymers as anti-corrosion materials. The corrosion is a redox reaction proceeding through the local cell mechanism : the iron oxidation half-cell reaction at the local anode and the reduction of oxygen at the local cathode. To prepare a teaching tool for understanding of the mechanism, the visualization of the corrosion was attempted using phenolphthalein and potassium hexacyanoferrate (III) as color couplers for the anodic and cathodic products : Fe2+ and OH-. The local anode and cathode were obviously shown as gradual blue and red coloration when commercial nails were soaked in 4% NaCl aqueous solution containing phenolphthalein and potassium hexacyanoferrate (III) . On the other hand, no coloration occurred for the nail covered with a conductive polymer polyaniline. To know the anti-corrosion mechanism, the open-circuit potential of the nail was measured. The fact that the potential was kept at the potential range where iron was passivated implied that polyaniline acted as an in-situ oxidant. The visualization was experimentally performed at an actual chemistry class and the utility value was estimated. As a result, the visualization is expected to be a useful teaching tool for the corrosion and the understanding of the role of polyaniline as the anti-corrosion material.

Yano, Jun; Nakamura, Noriyuki; Yamazaki, Suzuko; Ichimori, Hayato; Osaki, Nobukazu; Okano, Hiroshi

34

Identification and Determination of Synthetic Pharmaceuticals as Adulterants in Eight Common Herbal Weight Loss Supplements  

PubMed Central

Background: Adulterated herbal weight loss products with containing undeclared synthetic drugs are common and responsible for many serious health damages. Objectives: The purpose of the study was to determine five synthetic adulterants in eight common herbal weight loss supplements, which are currently sold in Iran markets, to verify their presence in supplements, without mentioning on the labels. Materials and Methods: Eight common herbal weight loss samples were obtained from the Iran pharmaceutical market after advertising in the Persian language on satellite channels and internet. Five pharmacological classes of drugs used for weight loss, namely sibutramine, phenolphthalein, phenytoin, bumetanide and rimonabant, were investigated and quantified by GC-MS for the first three and LC-MS for the last two medications. Results: The most undeclared ingredients, which were illegally added include sibutramine, phenolphthalein, bumetanide, and phenytoin in the original super slim, herbaceous essence, super slim green lean, and fat loss, supplements, respectively. Rimonabant was not found. Caffeine, pseudoephedrine, theobromine and amfepramone were also found in the supplements using GC-MS assay. Conclusions: Adulterated synthetic substances were detected in the herbal weight loss products. Health care professionals should make people aware of the risks of taking herbal weight-loss supplements. PMID:24829782

Khazan, Marjan; Hedayati, Mehdi; Kobarfard, Farzad; Askari, Sahar; Azizi, Fereidoun

2014-01-01

35

Thermochemical characterization of some thermoplastic materials. [flammability and toxicity properties for aircraft interiors  

NASA Technical Reports Server (NTRS)

The thermochemical and flammability characteristics of some typical thermoplastic materials currently in use or being considered for use in aircraft interiors are described. The properties studied included thermomechanical properties such as glass-transition and melt temperature, changes in polymer enthalpy, thermogravimetric analysis in anerobic and oxidative environments, oxygen index, smoke evolution, relative toxicity of the volatile products of pyrolysis, and selected physical properties. The generic polymers evaluated included acrylonitrile butadiene styrene, bisphenol A polycarbonate, 9,9 bis (4-hydroxyphenyl) fluorene polycarbonate-poly (dimethylsiloxane) block polymer, phenolphthalein-bisphenol A polycarbonate, phenolphthalein polycarbonate, polyether sulfone, polyphenylene oxide, polyphenylene sulfide, polyaryl sulfone, chlorinated polyvinyl chloride homopolymer, polyvinyl fluoride, and polyvinylidene fluoride. Processing parameters, including molding characteristics of some of the advanced polymers, are described. Test results and relative rankings of some of the flammability, smoke, and toxicity properties are presented. Under these test conditions, some of the advanced polymers evaluated were significantly less flammable and toxic than or equivalent to polymers in current use.

Kourtides, D. A.; Parker, J. A.; Hilado, C. J.

1977-01-01

36

Determination of Chlorinity of Water without the Use of Chromate Indicator  

PubMed Central

A new method for determining chlorinity of water was developed in order to improve the old method by alleviating the environmental problems associated with the toxic chromate. The method utilizes a mediator, a weak acid that can form an insoluble salt with the titrant. The mediator triggers a sudden change in pH at an equivalence point in a titration. Thus, the equivalence point can be determined either potentiometrically (using a pH meter) or simply with an acid-base indicator. Three nontoxic mediators (phosphate, EDTA, and sulfite) were tested, and optimal conditions for the sharpest pH changes were sought. A combination of phosphate (a mediator) and phenolphthalein (an indicator) was found to be the most successful. The choices of the initial pH and the concentration of the mediator are critical in this approach. The optimum concentration of the mediator is ca. 1~2?mM, and the optimum value of the initial pH is ca. 9 for phosphate/phenolphthalein system. The method was applied to a sample of sea water, and the results are compared with those from the conventional Mohr-Knudsen method. The new method yielded chlorinity of a sample of sea water of (17.58 ± 0.22)?g/kg, which is about 2.5% higher than the value (17.12 ± 0.22) g/kg from the old method. PMID:21461358

Hong, Tae-Kee; Kim, Myung-Hoon; Czae, Myung-Zoon

2010-01-01

37

Approaches to flame resistant polymeric materials  

NASA Technical Reports Server (NTRS)

Four research and development areas are considered for further exploration in the quest of more flame-resistant polymeric materials. It is suggested that improvements in phenolphthalein polycarbonate processability may be gained through linear free energy relationship correlations. Looped functionality in the backbone of a polymer leads to both improved thermal resistance and increased solubility. The guidelines used in the pyrolytic carbon production constitute a good starting point for the development of improved flame-resistant materials. Numerous organic reactions requiring high temperatures and the techniques of protected functionality and latent functionality constitute the third area for exploration. Finally, some well-known organic reactions are suggested for the formation of polymers that were not made before.

Liepins, R.

1975-01-01

38

Structural Relaxations and Thermodynamic Properties of Molecular Amorphous Solids by Mechanical Milling  

NASA Astrophysics Data System (ADS)

The organic crystals of tri-O-methyl-?-cyclodextrin (TMCD) and its three clathrate compounds containing benzoic acid (BA), p-nitrobenzoic acid (NBA) and p-hydroxybenzoic acid (HBA), sucrose (SUC), salicin (SAL), phenolphthalein (PP), 1,3,5-tri-?-naphthylbenzene (TNB) were amorphized by milling with a vibrating mill for 2 ˜ 16 hours at room temperature. The amorphization was checked by differential scanning calorimetry (DSC) and X-ray powder diffraction. The heat capacities of crystals, liquid quenched glasses (LQG), and mechanically-milled amorphous solid (MMAS) of TMCD and TNB were measured with an adiabatic calorimeter in the temperature range between 12 and 375 K. For both compounds, the enthalpy relaxation of MMAS appeared in the wide temperature range below Tg and the released configurational enthalpy was much larger than that of LQG, indicating that MMAS is more disordered and strained than LQG.

Tsukushi, I.; Yamamuro, O.; Matsuo, T.

39

Solid state amorphization of organic molecular crystals using a vibrating mill  

NASA Astrophysics Data System (ADS)

The solid-state amorphization of organic molecular crystals was studied by differential scanning calorimetry (DSC) and X-ray powder diffraction. Two clathrate compounds of tri- O-methyl-?-cyclodextrin (TMCD) containing p-nitrobenzoic acid (NBA) and p-hydroxybenzoic acid (HBA), and seven other organic compounds, sucrose (SUC), salicin (SAL), phenolphthalein (PP), 1,3,5-tri-?-naphthylbenzene (TNB), p-quaterphenyl ( p-QP), p-terphenyl ( p-TP) and 1,3,5-triphenylbenzene (TPB) were ground for 2-16 h with a vibrating mill at room temperature. A halo diffraction pattern and exothermic effect due to the crystallization were observed in TMCD-NBA, TMCD-HBA, SUC, SAL, PP and TNB, indicating amorphization of these crystals. The ability of solid-state amorphization in organic molecular crystals was discussed from a thermodynamic point of view.

Tsukushi, Itaru; Yamamuro, Osamu; Matsuo, Takasuke

1995-06-01

40

A plate method for screening of bacteria capable of degrading aliphatic nitriles.  

PubMed

A novel indicator plate method was developed for screening of aliphatic-nitrile-degrading bacteria. Isolated bacteria were tested for utilization of acetonitrile as sole source of carbon and nitrogen with the release of ammonia. The released ammonia causes increase of the pH of the medium. Phenol red indicator is used for detection of ammonia based on colour change of the indicator dye from red to pink. The liberation of ammonia from aliphatic-nitrile-utilizing bacteria is also studied in plates containing other indicators such as bromothymol blue and phenolphthalein. The usefulness of the indicator plate is demonstrated for bacteria that degrade certain aliphatic nitriles. Bacteria degrading nitriles as a nitrogen source can also be isolated with a medium containing additional carbon source. This plate method would be useful in isolation and screening of bacteria for degradation of aliphatic nitriles and also for production of nitrile-hydrolyzing enzymes. PMID:19921293

Santoshkumar, M; Nayak, Anand S; Anjaneya, O; Karegoudar, Timmanagouda B

2010-01-01

41

Sequestration of CO2 by concrete carbonation.  

PubMed

Carbonation of reinforced concrete is one of the causes of corrosion, but it is also a way to sequester CO2. The characteristics of the concrete cover should ensure alkaline protection for the steel bars but should also be able to combine CO2 to a certain depth. This work attempts to advance the knowledge of the carbon footprint of cement. As it is one of the most commonly used materials worldwide, it is very important to assess its impact on the environment. In order to quantify the capacity of cement based materials to combine CO2 by means of the reaction with hydrated phases to produce calcium carbonate, Thermogravimetry and the phenolphthalein indicator have been used to characterize several cement pastes and concretes exposed to different environments. The combined effect of the main variables involved in this process is discussed. The moisture content of the concrete seems to be the most influential parameter. PMID:20225850

Galan, Isabel; Andrade, Carmen; Mora, Pedro; Sanjuan, Miguel A

2010-04-15

42

Flammability and Photo-Stability of Selected Polymer Systems  

NASA Technical Reports Server (NTRS)

A systematic approach to the improvement of the flammability of epoxy resins, bisphenol-A polycarbonate poly(butylene terephthalate), and Nylon 6.6 by introducing halogens and loop functionality into the flame retardants is described. The phthalides (the loop functionality containing molecules) include 3,3-bis(4-bromophenyl)-phthalide, 3,3-bis(4-chlorophenyl)phthalide, and phenolphthalein. The phthalide containing epoxy resins are synthesized and characterized in comparison with the bisphenol-A epoxy resins in terms of flammability in the copolymer systems. The resins include diglycidyl ethers of phenolphthalein, bisphenol-A. tetrabromobisphenol-A, and tetraoromophenolphthalein. The vaporization of the phthalide additive in the polymers is observed in Thermal Gravimetric Analysis. The flame retardancy is primarily due to the presence of halogens. In the poly(butylene terephthalate) system, the cleavage of the C(sub aromatic) -B bond of the flame retardant additive enhances the crosslinking react ions between the aromatic rings resulting in an increase of char formation. In the epoxy resin systems, loop functionality contributes to char formation to a larger extent. The interaction between the epoxy resin and poly-(butylene terephthalate) follows the mechanism of insertion of the oxirane ring into the ester bond. This mechanism is studied by FT-IR. The investigation of the thermal properties of the char-forming phenol-formaldehyde resins is conducted to provide information for the systematic design of high temperature flame-resistant phenolics. NMR and FT-IR are used to characterize the oligomeric resins and the cured resins. The curing agents used in the study include formaldehyde, s-trioxane and terephthaloyl chloride. The brominated phenolic resins are found to have higher oxygen indices with lower char yields.

Lo, Jeelin

1981-01-01

43

An improved microfluidics approach for monitoring real-time interaction profiles of ultrafast molecular recognition.  

PubMed

Our study illustrates the development of a microfluidics (MF) platform combining fluorescence microscopy and femtosecond/picosecond-resolved spectroscopy to investigate ultrafast chemical processes in liquid-phase diffusion-controlled reactions. By controlling the flow rates of two reactants in a specially designed MF chip, sub-100 ns time resolution for the exploration of chemical intermediates of the reaction in the MF channel has been achieved. Our system clearly rules out the possibility of formation of any intermediate reaction product in a so-called fast ionic reaction between sodium hydroxide and phenolphthalein, and reveals a microsecond time scale associated with the formation of the reaction product. We have also used the developed system for the investigation of intermediate states in the molecular recognition of various macromolecular self-assemblies (micelles) and genomic DNA by small organic ligands (Hoechst 33258 and ethidium bromide). We propose our MF-based system to be an alternative to the existing millisecond-resolved "stopped-flow" technique for a broad range of time-resolved (sub-100 ns to minutes) experiments on complex chemical?biological systems. PMID:22559521

Batabyal, Subrata; Rakshit, Surajit; Kar, Shantimoy; Pal, Samir Kumar

2012-04-01

44

Functional heterogeneity of UDP-glucuronosyltransferase as indicated by its differential development and inducibility by glucocorticoids. Demonstration of two groups within the enzyme's activity towards twelve substrates.  

PubMed Central

1. UDP-glucuronosyltransferase activity towards 12 substrates has been assessed in rat liver during the perinatal period. 2. Between days 16 and 20 of gestation, enzyme activities towards the substrates 2-aminophenol, 2-aminobenzoate, 4-nitrophenol, 1-naphthol, 4-methylumbelliferone and 5-hydroxytryptamine (the 'late foetal' group) surge to reach adult values, while activities towards bilirubin, testosterone, beta-oestradiol, morphine, phenolphthalein, and chloramphenicol (the 'neonatal' group) remain negligible or at less than 10% of adult values. 3. By the second postnatal day, enzyme activities towards the neonatal group have attained, or approached adult values. 4. Dexamethasone precociously stimulates in 17-day foetal liver in utero transferase activities in the late foetal, but not the neonatal group. A similar inductive pattern is found for 15-day foetal liver in organ culture. 5. It is suggested that foetal glucocorticoids, whose synthesis markedly increases between days 16 and 20 of gestation, are responsibile for triggering the simultaneous surge of all the hepatic UDP-glucuronosyltransferase activities in the late foetal group. The neonatal group of activities apparently require a different or additional stimulus for their appearance. 6. The relationship of these two groups of transferase activities to other similar groups observed during induction by xenobiotics and enzyme purification is discussed. PMID:101211

Wishart, G J

1978-01-01

45

High Performance Microreactor for Rapid Fluid Mixing and Redox Reaction of Ascorbic Acid  

E-print Network

A novel micro device with a mechanism of split and recombination (SNR) for rapid fluidic mixing and reaction, named a SNR micro-reactor, was designed, fabricated and systematically analyzed. This SNR micro-reactor possessing an in-plane dividing structure requires only simple fabrication. We investigated this reactor and compared it numerically and experimentally with a slanted-groove micromixer (SGM). From the numerical results the mixing indices and mixing patterns demonstrated that the mixing ability of the SNR micro-reactor was much superior to that of the SGM. From a mixing test with phenolphthalein and sodium hydroxide solutions, the mixing lengths of the SNR micro-reactor were less than 4 mm for a Reynolds number over a wide range (Re = 0.1 - 10). From a comparison of mixing lengths, the results revealed also that the SNR micro-reactor surpassed the SGM in mixing performance by more than 200 %. As a reaction length is a suitable test of the performance of a reactor, we introduced a redox reaction betwe...

Fang, Wei-Feng

2008-01-01

46

Comparison of Salivary Beta Glucuronidase Activity in Chronic Periodontitis Patients with and without Diabetes Mellitus  

PubMed Central

Aim of the study: The aim of the study was to estimate the salivary beta glucuronidase (?) activity in patients with chronic periodontitis with and without diabetes mellitus and to evaluate the relationship between Beta Glucuronidase activity and Periodontal clinical parameters. Materials and Methods: The study consisted of 80 patients of both sexes with age ranging from 20-60 years and they were divided into four groups. Clinical parameters such as Gingival index, Probing depth and Clinical attachment loss were measured. Salivary Beta Glucuronidase activity was measured using spectrophotometer with reagents like phenolphthalein glucuronic acid, phosphate and glycine buffer. Results: The mean BG activity of Group IV (1.17 ± 0.27) was significantly higher than mean BGA levels of Group I, II, III. The p-value was < 0.05. The mean BGA levels of Group III (0.78 ± 0.17) was significantly higher than mean BGA levels of Group I, Group II at 5 % level. There was a significant positive linear relationship between salivary ? Glucuronidase level and Probing Depth, clinical attachment level in the experimental Groups. Conclusion: The salivary ? Glucuronidase level was higher in Diabetic patients with periodontitis than nondiabetic periodontitis patients. PMID:25121058

ND, Jayakumar; Varghese, Sheeja

2014-01-01

47

A serpentine laminating micromixer combining splitting/recombination and advection.  

PubMed

Mixing enhancement has drawn great attention from designers of micromixers, since the flow in a microchannel is usually characterized by a low Reynolds number (Re) which makes the mixing quite a difficult task to accomplish. In this paper, a novel integrated efficient micromixer named serpentine laminating micromixer (SLM) has been designed, simulated, fabricated and fully characterized. In the SLM, a high level of efficient mixing can be achieved by combining two general chaotic mixing mechanisms: splitting/recombination and chaotic advection. The splitting and recombination (in other terms, lamination) mechanism is obtained by the successive arrangement of "F"-shape mixing units in two layers. The advection is induced by the overall three-dimensional serpentine path of the microchannel. The SLM was realized by SU-8 photolithography, nickel electroplating, injection molding and thermal bonding. Mixing performance of the SLM was fully characterized numerically and experimentally. The numerical mixing simulations show that the advection acts favorably to realize the ideal vertical lamination of fluid flow. The mixing experiments based on an average mixing color intensity change of phenolphthalein show a high level of mixing performance was obtained with the SLM. Numerical and experimental results confirm that efficient mixing is successfully achieved from the SLM over the wide range of Re. Due to the simple and mass producible geometry of the efficient micromixer, SLM proposed in this study, the SLM can be easily applied to integrated microfluidic systems, such as micro-total-analysis-systems or lab-on-a-chip systems. PMID:15970967

Kim, Dong Sung; Lee, Se Hwan; Kwon, Tai Hun; Ahn, Chong H

2005-07-01

48

Fabrication of round channels using the surface tension of PDMS and its application to a 3D serpentine mixer  

NASA Astrophysics Data System (ADS)

A novel fabrication technique was developed to fabricate round microchannels and applied to a micro mixer having a barrier structure using surface tension of PDMS. When the solidified PDMS layer (channel layer) contacts the liquid PDMS film (meniscus layer), a meniscus is formed around the sidewall in the microchannel due to surface tension. The external load pressure and contact area of the channel layer were adjusted to form various cross-sectional shapes such as a U shape, ellipse, semi-circle and circle. Since the width of the channel also determines the depth formed by the difference in capillary height, a multi-depth channel can be fabricated using a one-step process. It was applied to a dual-depth serpentine mixer, eliminating the aligned bonding of conventional soft lithography. The 3D-structure mixer enhanced mixing performance in the range of Re > 10 compared with a 2D-structure. It could fully mix phenolphthalein and sodium hydroxide when the Reynolds number was 80. The suggested fabrication method could be very useful in various microfluidic devices that need round corners and multi-depth channels.

Lee, Kangsun; Kim, Choong; Shin, Kyeong Sik; Lee, Jin Woo; Ju, Byeong-Kwon; Kim, Tae Song; Lee, Seung-Ki; Kang, Ji Yoon

2007-08-01

49

Poly(?-caprolactone) nanowebs functionalized with ?- and ?-cyclodextrins.  

PubMed

The effects of alpha- and gamma-cyclodextrins (?- and ?-CDs) on the thermal and crystal nucleation behavior of electrospun poly(?-caprolactone) (PCL) nanofibers have been investigated. PCL/CD composite nanofibers were obtained for the first time by electrospinning the mixture from chloroform/N,N-dimethylformamide (60:40). Scanning electron microscopy analyses indicated that neat PCL nanofibers have an average diameter of 400 nm, which increases with the addition of CDs. The presence of CDs on or in the electrospun PCL fibers in the electrospun mats was investigated using Fourier transform infrared spectroscopy, thermogravimetric analysis, and wide-angle X-ray diffraction analysis. Differential scanning calorimetry showed that the PCL/CD composite fibers exhibit higher crystallization temperatures and sharper crystallization exotherms with increased CD loading, indicating the ability of CDs to nucleate PCL crystallization. Water contact angle (WCA) measurements indicate an inverse relationship between WCA and ?- or ?-CD concentration up to 30% loading. Phenolphthalein absorption tests were performed to study the kinetics of their inclusion complex (IC) formation with CDs. Unexpectedly, ?-CD-functionalized nanowebs performed better than ?-CD. This might be because at elevated loadings some ?-CDs may have threaded over PCL chains and formed ICs, whereas ?-CD did not. With their encapsulation capabilities and their lowered hydrophobicity, PCL/CD composite fibers might have potential uses in medical applications, in particular as wound odor absorbants in dressings, because it is well known that CDs can form ICs with these odorants, thereby effectively removing them. PMID:25296366

Narayanan, Ganesh; Gupta, Bhupender S; Tonelli, Alan E

2014-11-10

50

Time evolution of the fractal dimension of a mixing front  

NASA Astrophysics Data System (ADS)

We present a description of an experimental study of an array of turbulent plumes (from one to nine plumes), investigating the time evolution of the fractal dimension of the plumes and also the spatial evolution of the fractal dimension from one plume to other. We also investigate the effects of bouyancy (different Atwood numbers), the number of plumes and the height of the bouyancy source on the fractal dimension. The plumes are formed by injecting a dense fluid from a small source (from one to nine orifices) into a stationary body of lighter brime (saline solution) contained in a tank. The source fluid was dyed with fluorescein and we use the LIF technique. The plumes were fully turbulent and we have both momentum and bouyancy regimes. The fractal dimensions of contours of concentration were measured. The fractal analysis of the turbulent convective plumes was performed with the box counting algorithm for different intensities of evolving plume images using the special software Ima_Calc. Fractal dimensions between 1.3 and 1.35 are obtained from box counting methods for free convection and neutral boundary layers. Other results have been published which use the box counting method to analyze images of jet sections -produced from LIF techniques. The regions where most of the mixing takes place are also compared with Reactive flow experiments using phenolphthalein and acid-base interfaces performed by Redondo(1994) IMA 43. Eds M. Farge, JC Hunt and C. Vassilicos.

Lopez Gonzalez-Nieto, P.; Grau, J.

2009-04-01

51

Mixing in colliding, ultrasonically levitated drops.  

PubMed

Lab-in-a-drop, using ultrasonic levitation, has been actively investigated for the last two decades. Benefits include lack of contact between solutions and an apparatus and a lack of sample cross-contamination. Understanding and controlling mixing in the levitated drop is necessary for using an acoustically levitated drop as a microreactor, particularly for studying kinetics. A pulsed electrostatic delivery system enables addition and mixing of a desired-volume droplet with the levitated drop. Measurement of mixing kinetics is obtained by high-speed video monitoring of a titration reaction. Drop heterogeneity is visualized as 370 nl of 0.25 M KOH (pH: 13.4) was added to 3.7 ?L of 0.058 M HCl (pH: 1.24). Spontaneous mixing time is about 2 s. Following droplet impact, the mixed drop orbits the levitator axis at about 5 Hz during homogenization. The video's green channel (maximum response near 540 nm) shows the color change due to phenolphthalein absorption. While mixing is at least an order of magnitude faster in the levitated drop compared with three-dimensional diffusion, modulation of the acoustic waveform near the surface acoustic wave resonance frequency of the levitated drop does not substantially reduce mixing time. PMID:24460103

Chainani, Edward T; Choi, Woo-Hyuck; Ngo, Khanh T; Scheeline, Alexander

2014-02-18

52

Therapeutic proposals for the treatment of idiopathic constipation.  

PubMed

The objectives to be achieved by a medical therapy of constipation are: 1) to protect the patient from excessive use of dangerous drugs (laxatives), 2) to help the patient to understand what is a "normal" intestinal function, 3) to reduce or eliminate pain and 4) to avoid complications. The first step consists in general measures (reduced stress, regular meals and physical exercise) and some modifications in diet habits (greater than 1.5 1 of water a day, vegetables, fruits, whole wheat bread). The pharmacological therapy is based on drugs which act in different ways: a) some contain unabsorbable substances (i.e. cellulose, emicellulose) that increase the volume of the stools: b) unabsorbable sugars (i.e. lactulose, lactose) or salts (Mg-sulphate, citrate and Na-sulphate) that provoke an osmotic effect and stimulate the colonic motility; c) suppositories that stimulate the defecation reflex; d) drugs able to stimulate colonic secretion and propulsive motility (i.e. anthraquinones, oral bisacodyl, phenolphthalein, castor oil, prokinetics). There are many conditions in which medical therapy fails its objective: in these cases it is important to exclude other causes of constipation (i.e. drug-related constipation, endocrine disorders, metabolic diseases, systemic illnesses or lesion of the enteric plexus) in order to obtain an improvement of this symptom. PMID:1661627

Sàez, L R

1991-11-01

53

Effects of subacute treatment with cocaine on activities of n-demethylase, UDP-glucuronyltransferase and sulfotransferase in WKY and SHR rat liver - sex and strain differences  

SciTech Connect

The effects of subacute treatment with cocaine on activities of cocaine N-demethylase, UDP-glucuronyltransferase (GT) toward 4-nitrophenol and phenolphthalein and sulfotransferase (ST) toward androsterone and 4-nitrophenol in livers from Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were investigated. Hepatic metabolism of cocaine was different between the sexes (with males having higher N-demethylase activity) and the strains (with WKY rats having higher activity). The effects of subacute cocaine administration on the activity of cocaine N-demethylase were also sex- and strain-related. Whereas cocaine administration increased activity of hepatic N-demethylase in both female strains, it decreased activity in male WKY and had no effect on activity in male SHR. Sex and strain-related as well as cocaine-induced differences were also found in activities of hepatic GT toward 4-nitrophenol and phenolphtalein as well as in activity of hepatic ST towards andersterone and 4-nitrophenol. These results suggest that some of the individual variation in the effects of cocaine may be due to sex and genetic differences in the hepatic metabolism of cocaine and/or in sexually and/or genetically-determined differences in how cocaine affects hepatic metabolism of other xenobiotics. 20 references, 4 figures.

Watanabe, H.K.; Hoskins, B.; Ho, I.K.

1988-01-01

54

Quantitative estimation of carbonation and chloride penetration in reinforced concrete by laser-induced breakdown spectroscopy  

NASA Astrophysics Data System (ADS)

The penetration profile of chlorine in a reinforced concrete (RC) specimen was determined by laser-induced breakdown spectroscopy (LIBS). The concrete core was prepared from RC beams with cracking damage induced by bending load and salt water spraying. LIBS was performed using a specimen that was obtained by splitting the concrete core, and the line scan of laser pulses gave the two-dimensional emission intensity profiles of 100 × 80 mm2 within one hour. The two-dimensional profile of the emission intensity suggests that the presence of the crack had less effect on the emission intensity when the measurement interval was larger than the crack width. The chlorine emission spectrum was measured without using the buffer gas, which is usually used for chlorine measurement, by collinear double-pulse LIBS. The apparent diffusion coefficient, which is one of the most important parameters for chloride penetration in concrete, was estimated using the depth profile of chlorine emission intensity and Fick's law. The carbonation depth was estimated on the basis of the relationship between carbon and calcium emission intensities. When the carbon emission intensity was statistically higher than the calcium emission intensity at the measurement point, we determined that the point was carbonated. The estimation results were consistent with the spraying test results using phenolphthalein solution. These results suggest that the quantitative estimation by LIBS of carbonation depth and chloride penetration can be performed simultaneously.

Eto, Shuzo; Matsuo, Toyofumi; Matsumura, Takuro; Fujii, Takashi; Tanaka, Masayoshi Y.

2014-11-01

55

Study of dynamics and crystallization kinetics of 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile at ambient and elevated pressure  

NASA Astrophysics Data System (ADS)

The organic liquid ROY, i.e., 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile, has been a subject of detailed study in the last few years. One interest in ROY lies in its polymorph-dependent fast crystal growth mode below and above the glass transition temperature. This growth mode is not diffusion controlled, and the possibility that it is enabled by secondary relaxation had been suggested. However, a previous study by dielectric relaxation spectroscopy had not been able to find any resolved secondary relaxation. The present paper reports new dielectric measurements of ROY in the liquid and glassy states at ambient pressure and elevated pressure, which were performed to provide more insight into the molecular dynamics as well as the crystallization tendency of ROY. In the search of secondary relaxation, a special glassy state of ROY was prepared by applying high pressure to the liquid state, from which secondary relaxation was possibly resolved. Thus, the role of secondary relaxation in crystallization of ROY remains to be clarified. Notwithstanding, the secondary relaxation present is not necessarily the sole enabler of crystallization. In an effort to search for possible cause of crystallization other than secondary relaxation, we also performed crystallization kinetics studies of ROY at different T and P combinations while keeping the structural relaxation time constant. The results show that crystallization of ROY speeds up with pressure, opposite to the trend found in the crystallization of ibuprofen studied up to 1 GPa. The dielectric relaxation and thermodynamic properties of ROY with phenolphthalein dimethylether (PDE) are similar in many respects, but PDE does not crystallize. Taking all the above into account, besides the secondary relaxation, the specific chemical structure, molecular interactions and packing of the molecules are additional factors that could affect the kinetics of crystallization found in ROY.

Adrjanowicz, K.; Kaminski, K.; Paluch, M.; Ngai, K. L.; Yu, Lian

2012-06-01

56

Potentiation of bromotrichloromethane hepatotoxicity and lethality by chlordecone preexposure in the rat.  

PubMed

These studies were designed to provide dose-response relationships for chlordecone (CD) potentiation of BrCCl3 hepatotoxicity in male rats using biochemical, functional and histopathological parameters. The influence of this interaction on BrCCl3 lethality was also examined. Male Sprague-Dawley rats (175-200 g) received a single ip dose of 1, 5, 10, 15 or 25 microL BrCCl3/kg following a 15 day dietary pretreatment of 0 or 10 ppm CD. Twenty four hrs after BrCCl3 challenge, biliary excretion of phenolphthalein glucuronide (PG), bile flow, serum transaminases (SGOT and SGPT), serum ICD and OCT were examined as functional and biochemical indices of hepatic injury. Effect of CD on 48 hr LD50 of BrCCl3 was also examined using the method of moving averages. With the exception of 1 microL BrCCl3/kg dose which had no effect, CD-BrCCl3 combination resulted in potentiation of hepatotoxicity by all parameters examined. Activity of all the serum enzymes was elevated in a dose related manner. A dose related decrease in the biliary excretion of PG and bile flow was observed. These effects were more pronounced at the higher doses of BrCCl3. Extensive centrilobular necrosis was observed in the animals given CD-BrCCl3 combination and the necrogenic effect was more severe at the doses of 15 microL and 25 microL BrCCl3/kg. BrCCl3-lethality was increased 5-fold by CD as indicated by the decreased LD50. The results suggest that CD-induced BrCCl3 toxicity is manifested both in the form of hepatotoxicity and lethality and since the hepatic functional status is greatly compromised, the CD potentiated hepatic failure is related to lethality. PMID:6193023

Agarwal, A K; Mehendale, H M

1982-01-01

57

Comparative Evaluation of Four Presumptive Tests for Blood to Detect Epithelial Injury on Fish  

SciTech Connect

Current methods of fish epithelial injury detection are limited to gross macroscopic examination that has a subjective bias as well as an inability to reliably quantify the degree of injury. Fluorescein, a presumptive test for blood, has been shown to have the capability to detect and quantify fish epithelial injury. However, there are several other presumptive tests for blood (Bluestar*, phenolphthalein, and HemastixH) that may have benefits over the use of fluorescein, particularly for field research on wild fish. This study investigated the capabilities of these four tests to detect and quantify a variety of injuries commonly encountered by fish (abrasion, cuts, fin frays, and punctures) using the freshwater bluegill Lepomis macrochirus as a model. Fluorescein was consistently found to be the most reliable (i.e., detected the highest proportion of true positive results and rarely detected false positive reactions) of the four presumptive tests for blood compared. Further testing was conducted to examine the reliability of fluorescein. By 24 h after an injury was inflicted, the injury was no longer detectable by fluorescein, and when fluorescein was applied to an injured fish, the fluorescein was no longer detectable 3 h after application. In a comparison of two common anaesthetics used in fisheries research, there was no significant difference in the proportion of injury detected when 3- aminobenzoic acid ethyl ester methanesulfate (tricaine) was used compared with a clove oil and ethanol (1:9) solution. In summary, fluorescein was the most reliable presumptive test for blood examined in this study for the detection and quantification of recent (hours) fish epithelial injury.

Colotelo, Alison HA; Smokorowski, Karen; Haxton, Tim; Cooke, Steven J.

2014-06-01

58

An accurate and reproducible method for the quantitative analysis of isoflavones and their metabolites in rat plasma using liquid chromatography/mass spectrometry combined with photodiode array detection.  

PubMed

To study the safety and potential health benefits of soy isoflavones, a rapid and simple method based on liquid chromatography combined with mass spectrometry (LC/MS) and photodiode array detector (PDA) was developed for the determination of isoflavones in rat plasma. The analytes included daidzein, genistein, glycitein, equol, 4-ethyl phenol, and biochanin A over a concentration range of 1.0-4320.0 nM using 75 microL of rat plasma. Rat plasma samples were hydrolyzed by adding an enzyme mixture from Helix pomatia containing glucuronidase and sulfatase to convert the isoflavone beta-glycosides daidzin, genistin, and glycitin to their active aglycone forms. A liquid-liquid extraction method using ethyl acetate as the extraction solvent was used to extract aglycones and the internal standards (phenolphthalein beta-D glucuronide, 4-methylumbelliferyl sulfate, and apigenin) from digested plasma samples. The extract was evaporated to dryness under a nitrogen stream, reconstituted with 0.1% formic acid in water-acetonitrile (85 + 15), and injected into a Zorbax SB-CN reversed-phase column (4.6 x 75 mm, 3.5 microm particle size). The Micromass ZQ detector was operated in the positive ion selected-ion monitoring mode. The flow rate for LC was 1.0 mL/min, with a split where 25% of the effluent was introduced into the electrospray ionization probe of the MS instrument and 75% into the PDA. The chromatographic run time was 16.0 min, with delay of 10 min/injection. The interday precision and accuracy of the standard samples were <2.6% relative standard deviation and <10% relative error, respectively. Recovery of the reported isoflavones with this method varied from 86 to 100%. PMID:16915859

Sepehr, Estatira; Robertson, Patrick; Gilani, G Sarwar; Cooke, Gerard; Lau, Benjamin Pui-Yan

2006-01-01

59

Novel approaches to analysis by flow injection gradient titration.  

PubMed

Two novel procedures for flow injection gradient titration with the use of a single stock standard solution are proposed. In the multi-point single-line (MP-SL) method the calibration graph is constructed on the basis of a set of standard solutions, which are generated in a standard reservoir and subsequently injected into the titrant. According to the single-point multi-line (SP-ML) procedure the standard solution and a sample are injected into the titrant stream from four loops of different capacities, hence four calibration graphs are able to be constructed and the analytical result is calculated on the basis of a generalized slope of these graphs. Both approaches have been tested on the example of spectrophotometric acid-base titration of hydrochloric and acetic acids with using bromothymol blue and phenolphthalein as indicators, respectively, and sodium hydroxide as a titrant. Under optimized experimental conditions the analytical results of precision less than 1.8 and 2.5% (RSD) and of accuracy less than 3.0 and 5.4% (relative error (RE)) were obtained for MP-SL and SP-ML procedures, respectively, in ranges of 0.0031-0.0631 mol L(-1) for samples of hydrochloric acid and of 0.1680-1.7600 mol L(-1) for samples of acetic acid. The feasibility of both methods was illustrated by applying them to the total acidity determination in vinegar samples with precision lower than 0.5 and 2.9% (RSD) for MP-SL and SP-ML procedures, respectively. PMID:17903467

Wójtowicz, Marzena; Kozak, Joanna; Ko?cielniak, Pawe?

2007-09-26

60

Self-Irradiation Effects on 99Mo Reagents and Products  

SciTech Connect

produced in 1996 and shipped to pharmaceutical houses for evaluation of compatibility with oxime solution used to precipitate `?vfo as the oxime complex is both air and light-sensitive, and containing a black precipitate that forms during shipment, presumably as a result of self- irradiation. Addition of sodium hypochlorite to the product solution prior to shipment prevents precipitate formation, indicating the precipitate is a reduced form of `%lo. to remove any precipitate. Duplicate aliquots of the filtered samples were titrated to a phenolphthalein irradiation and afler standing at room temperature for 86.4 hours. Precipitates were washed to a FTIR analysis of the white precipitate showed it to be alpha benzoin oxime. Since the basic After 86.4 hours, no precipitate had formed in bottles containing sodium hypochlorite. Black precipitate had formed in all bottles that did not contain sodium hypochlorite after 14.4 hours. The precipitate appeared to initially form on the surface of the HDPE sample bottles and Black precipitate was first noticed in sample set 1 after 28.8 hrs' irradiation. No visible sample containing precipitate was kept at room temperature in the original bottle. Precipitate in sample sets 2 and 3. Since no precipitate formed in these bottles, this was equivalent to duplicate samples. Once the precipitate in the 20-mL aliquots that had been set aside had returned to sample sets 1 through 3 and the samples with redissolved precipitate all experienced an average decrease in base strength of 0.013 meq mL-l. Sample 1-C had a decrease of 0.004 meq mL-l and sample 1-D had returned to the initial value of 0.198 meq mL-l. Raman spectra for the black precipitate from samples l-C, 1-D and supplemental sample set 1 Fig. 2. Raman spectra of the black precipitate formed in 9%40 product solutions after 28.8,43.2, 72 and 86.4 hours of `oCo irradiation in Sandia's Gamma Irradiation Facility. increase with time, as seen in the titration of 1-C and 1-D samples. The precipitate does not expect to see precipitate in the glass bottles. The fact that no precipitate is observed when the no precipitate is observed in a glass container is an indication that the rates of molybdenum that precipitate does not form when the solution is in a glass bottle. A hydrogen source other

Carson, S.D.; Garcia, M.J.; McDonald, M.J.; Simpson, R.L.; Tallant, D.R.

1998-10-07

61

Net alkalinity and net acidity 1: Theoretical considerations  

USGS Publications Warehouse

Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO2, and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined "CO 2-acidity" is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass- action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mg L -1 as CaCO3 (based on pH and analytical concentrations of dissolved FeII, FeIII, Mn, and Al in mg L -1):aciditycalculated=50{1000(10-pH)+[2(FeII)+3(FeIII)]/56+2(Mn)/ 55+3(Al)/27}underestimates contributions from HSO4- and H+, but overestimates the acidity due to Fe3+ and Al3+. However, these errors tend to approximately cancel each other. It is demonstrated that "net alkalinity" is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation, (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the value obtained in a standard method "hot peroxide" acidity titration, provided that labs report negative values. The authors recommend the third approach; i.e., net alkalinity = -Hot Acidity. ?? 2005 Elsevier Ltd. All rights reserved.

Kirby, C.S.; Cravotta, C.A., III

2005-01-01