scholarly journals Leaching of BPA from Baby Feeding Bottle, Aluminium Can and Thermal Printed Paper: Application of Acridine Orange Oxidation Inhibition Method to Estimate BPA

2021 ◽  
Vol 11 (3) ◽  
pp. 3738-3744
Keyword(s):  
Epoxy Resin ◽  
Acridine Orange ◽  
Estimation Method ◽  
Inhibitory Effect ◽  
Experimental Conditions ◽  
Pet Bottles ◽  
Plastic Materials ◽  
Thermal Paper ◽  
Uv Visible ◽  
Aluminum Cans

The potential of leaching Bisphenol-A (BPA) from plastic baby feeding bottles, aluminum cans, and thermal printed receipts was investigated under the aquatic condition at high temperatures. BPA is often used to manufacture cross-linked epoxy resin to coat food cans to prevent direct contact with metals and plastic materials. BPA leached from consumer product was analyzed using UV-Visible Spectrophotometer based on the inhibitory effect of BPA on acridine orange oxidation, as a function of change in temperature and time of contact of water with the samples. The proposed method of BPA estimation method was found to be significant and useful for aquatic conditions without any extraction and/or derivatization. The detection limit of BPA under the current experimental setup was 0.1 ng/ml. The results of BPA leached from baby feeding PET bottles, aluminum can with epoxy resin lining, and thermal paper were 87±10 ng/bottles, 68±5 ng/bottle, and 110±15 ng/receipt under the current experimental conditions.

scholarly journals BPA in Baby Feeding PET Bottle, Aluminium Can and Thermal Printed Paper: Application of Acridine Orange Oxidation Inhibition Method to Estimate BPA

2021 ◽  
Author(s):  
Shruti S. Kapse ◽  
Kumar Suranjit Prasad ◽  
Bablu Prasad
Keyword(s):  
High Temperature ◽  
Acridine Orange ◽  
Estimation Method ◽  
Inhibitory Effect ◽  
Experimental Setup ◽  
Experimental Conditions ◽  
Pet Bottles ◽  
Thermal Paper ◽  
Uv Visible ◽  
Current Experimental Setup

Abstract The leaching of Bisphenol-A (BPA) from plastic baby feeding bottles, aluminium cans and thermal printed receipts was investigated under aquatic condition at high temperature. Leached BPA was analysed using UV-Visible Spectrophotometer based on inhibitory effect of BPA on acridine orange oxidation, as a function of change in temperature and time of contact of water with the samples. Proposed method of BPA estimation method does not require any extraction and/or derivatization. The detection limit of BPA under current experimental setup was 0.1 ng/ml. The results of BPA leached from baby feeding PET bottles, aluminium can with epoxy resin lining and thermal paper were 87 ± 10 ng/bottles, 68 ± 5 ng/bottle and 110 ± 15 ng/receipt under the current experimental conditions.

The mobility of intramembrane particles in non-haemolysed human erythrocytes. Factors affecting acridine-orange-induced particle aggregation

1986 ◽  
Vol 86 (1) ◽  
pp. 57-67
Author(s):  
G. Lelkes ◽  
I. Fodor ◽  
G. Lelkes ◽  
S.R. Hollan
Keyword(s):  
Acridine Orange ◽  
Intracellular Ph ◽  
Lateral Diffusion ◽  
Inhibitory Effect ◽  
Human Erythrocytes ◽  
Particle Aggregation ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Cross Links ◽  
Phosphate Buffered Saline

It has previously been shown that reversible intramembrane particle aggregation can be induced in non-haemolysed human erythrocytes. This phenomenon, which can be induced by the cationic dye Acridine Orange, has been further investigated using different experimental conditions that are expected to influence the rate of aggregation of the particles. In addition to the concentration of the dye, the rate of aggregation was also found to be dependent on the extracellular and intracellular pH, as well as on the type of buffer used. While lowering the pH of the Acridine Orange solutions resulted in decreased particle clustering, low intracellular pH increased and elevated intracellular pH decreased particle aggregation. Furthermore, at a given dye concentration and a given pH, Acridine Orange caused more intense aggregation in Tris-buffered saline than in isotonic phosphate buffer or phosphate-buffered saline. Under appropriate conditions Acridine Orange caused significant particle aggregation at concentrations as low as 0.25 mM within 30 s. During this period only discocyte-stomatocyte transformation occurred; neither agglutination nor vesiculation of the erythrocytes could be detected. Treatment of the erythrocytes with Diamide (Serva), which cross-links spectrin via disulphide bridges and thereby reduces lateral diffusion of integral membrane proteins over large distances, had no inhibitory effect on Acridine-Orange-induced particle aggregation. Heating the erythrocytes to 50 degrees C, at which temperature denaturation of spectrin and fragmentation of the erythrocytes occur, and subsequently incubating them in Acridine Orange at room temperature, caused an almost maximal rate of particle aggregation within 10–30 s, without haemolysis. The possible mechanism and significance of the particle aggregation phenomenon are discussed.

Inhibiting Effect of Moroccan Medicinal Plants on Crystallization of Oxalo-calcic Calculations in vitro

2021 ◽  
Vol 1 (30) ◽  
pp. 18-26
Author(s):  
Abdelaziz ELAmrani El MostafaMtairag
Keyword(s):  
Medicinal Plants ◽  
Calcium Oxalate ◽  
Experimental Tests ◽  
Inhibitory Effect ◽  
Urinary Stones ◽  
Magnesium Ions ◽  
Experimental Conditions ◽  
Competitive Reactions ◽  
Uv Visible

Abstract- The aim of this work is to study the inhibitory effect of some Moroccan medicinal plants: parsley, nettle, oregano and corn beard on the crystallization of oxalocalcium urinary stones under experimental conditions which simu l a t e t h e u ri n a r y e n v ir o nme n t (physiological concentrations in calcium and oxalate, temperature and pH). The experimental tests were followed by the turbidimetric method using UV-Visible Model SP8-400 spectrophotometry, the response of which restores the concentration of calcium oxalate. The results showed that the potassium and magnesium ions which constitute the main elements of these plants compete with the calcium ions in order to combine with the oxalate ions. All the competitive reactions reflecting the affinities of the different ions towards each other contribute to the observed overall inhibition of the crystallization of calcium oxalate. Keywords: Crystallization, Urinary Calculus, Calcium oxalate, Inhibition, Moroccan Medicinal Plants

VARIATIONS IN PLASMA RENIN ACTIVITY AND URINARY ALDOSTERONE EXCRETION IN NORMAL SUBJECTS AFTER SALT RESTRICTION AND ACUTE PITUITARY INHIBITION WITH 6-DEHYDRO-16-METHYLENE HYDROCORTISONE

1971 ◽  
Vol 67 (1) ◽  
pp. 159-173
Author(s):  
A. Peytremann ◽  
R. Veyrat ◽  
A. F. Muller
Keyword(s):  
Plasma Renin Activity ◽  
Salt Intake ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Inhibitory Effect ◽  
Renin Activity ◽  
Sodium Balance ◽  
Experimental Conditions ◽  
Salt Restriction ◽  
Aldosterone Production

ABSTRACT Variations in plasma renin activity and urinary aldosterone excretion were studied in normal subjects submitted to salt restriction and simultaneous inhibition of ACTH production with a new synthetic steroid, 6-dehydro-16-methylene hydrocortisone (STC 407). At a dose of 10 mg t. i. d. this preparation exerts an inhibitory effect on the pituitary comparable to that of 2 mg of dexamethasone. In subjects maintained on a restricted salt intake, STC 407 does not delay the establishment of an equilibrium in sodium balance. The increases in endogenous aldosterone production and in plasma renin activity are also similar to those seen in the control subjects. A possible mineralocorticoid effect of STC 407 can be excluded. Under identical experimental conditions, the administration of dexamethasone yielded results comparable to those obtained with STC 407.

scholarly journals The Effect of pH, Ionic Strength and the Presence of PbII on the Formation of Calcium Carbonate from Homogenous Alkaline Solutions at Room Temperature

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 783
Author(s):  
Fulvio Di Lorenzo ◽  
Kay Steiner ◽  
Sergey V. Churakov
Keyword(s):  
Ionic Strength ◽  
Deep Understanding ◽  
Inhibitory Effect ◽  
Alkaline Solutions ◽  
Nucleation Kinetics ◽  
Experimental Conditions ◽  
Calcium Carbonates ◽  
Natural Systems ◽  
Geological Processes ◽  
System Variables

Precipitation of calcium carbonates in aqueous systems is an important factor controlling various industrial, biological, and geological processes. In the first part of this study, the well-known titration approach introduced by Gebauer and coworkers in 2008 s used to obtain reliable experimental dataset for the deep understanding of CaCO3 nucleation kinetics in supersaturated solutions over a broad range of pH and ionic strength conditions. In the second part, the effect of impurities, i.e., 1 mol% of Pb2+, was assessed in the same range of experimental conditions. Divalent lead has been shown to have an inhibitory effect in all ranges of the conditions tested except for pH 8 and low ionic strength (≤0.15 mol/L). Future investigations might take advantage of the methodology and the data provided in this work to investigate the effect of other system variables. The investigation of all the major variables and the assessment of eventual synergic effects could improve our ability to predict the formation of CaCO3 in complex natural systems.

scholarly journals Comparative investigation of lasing and amplification performance in cryogenic Yb:YLF systems

2021 ◽  
Vol 127 (3) ◽  
Author(s):  
Umit Demirbas ◽  
Martin Kellert ◽  
Jelto Thesinga ◽  
Yi Hua ◽  
Simon Reuter ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Estimation Method ◽  
Laser Cavity ◽  
Comparative Investigation ◽  
Limiting Factor ◽  
Experimental Conditions ◽  
Temperature Estimation ◽  
Transverse Temperature ◽  
First Time

AbstractWe present detailed experimental results with cryogenic Yb:YLF gain media in rod-geometry. We have comparatively investigated continuous-wave (cw) lasing and regenerative amplification performance under different experimental conditions. In the cw lasing experiments effect of crystal doping, cw laser cavity geometry and pump wavelength on lasing performance were explored. Regenerative amplification behavior was analyzed and the role of depolarization losses on performance was investigated. A recently developed temperature estimation method was also employed for the first time in estimating average crystal temperature under lasing conditions. It is shown that the thermal lens induced by transverse temperature gradients is the main limiting factor and strategies for future improvements are discussed. To the best of our knowledge, the achieved results in this study (375 W in cw, and 90 W in regenerative amplification) are the highest average powers ever obtained from this system via employing the broadband E//a axis.

Autoregulation of 3, 3′,5′-triiodothyronine production by rat liver microsomes

1981 ◽  
Vol 98 (2) ◽  
pp. 240-245 ◽  
Author(s):  
T. Kaminski ◽  
J. Köhrle ◽  
R. Ködding ◽  
R.-D. Hesch
Keyword(s):  
Rat Liver ◽  
Incubation Medium ◽  
Liver Microsomes ◽  
Inhibitory Effect ◽  
Incubation Mixture ◽  
Rat Liver Microsomes ◽  
Experimental Conditions ◽  
Physiological Concentration ◽  
Enzyme Binding ◽  
Ph Dependent

Abstract. Conversion of thyroxine (T4) to 3,3′,5′-triiodothyronine (rT3) was studied in rat liver microsomes. Addition of rT3 at a physiological concentration to the incubation medium inhibited the deiodination of thyroxine to rT3. With a concentration of rT3 greater than 37.6 nM no net rT3 production at pH 8.0 was observed. Further increases in rT3 concentration resulted only in degradation of added rT3 and no net synthesis of rT3 from T4 could be detected. The inhibitory effect of rT3 upon its own production from T4 was pH dependent, 5 fold lower amounts of hormone being required to inhibit completely rT3 production at pH 7.4 than at pH 8.0. With the same experimental conditions no significant effect of rT3 on the conversion of T4 to 3,5,3′-triiodothyronine (T3) could be observed at pH 8.0 with all concentrations of added iodothyronine. A linear production of 3,3′-T2 from added rT3 was determined over the whole range of rT3 concentration, suggesting a lack of saturation of deiodinating enzyme. Binding of rT3 by anti-rT3 antibody added to the incubation mixture enhanced rT3 production from T4 by protecting rT3 from being degraded and/or diminishing the inhibitory effect of this iodothyronine on its own production. It was concluded that rT3 influenced its own production and that this effect may represent an important autoregulatory process in the iodothyronine metabolism.

Free-base corroles: determination of deprotonation constants in non-aqueous media

2007 ◽  
Vol 11 (04) ◽  
pp. 269-276 ◽  
Author(s):  
Jing Shen ◽  
Zhongping Ou ◽  
Jianguo Shao ◽  
Michał Gałęzowski ◽  
Daniel T. Gryko ◽  
...  
Keyword(s):  
Equilibrium Constants ◽  
Aqueous Media ◽  
Free Base ◽  
Organic Base ◽  
Experimental Conditions ◽  
Spectral Changes ◽  
Base Analysis ◽  
Uv Visible ◽  
The Given

A series of free-base corroles with different electron-donating or electron-withdrawing substituents were reacted with piperidine, 4-aminopyridine, 2-methylimidazole, 2-aminopyridine or pyridine in PhCN and the UV-visible spectral changes monitored during conversion of ( Cor ) H 3 to [( Cor ) H 2]- as a function of the concentration and strength of the added organic base. Analysis of the UV-visible spectral changes as a function of the added base concentration enabled calculation of equilibrium constants ( logK ) for deprotonation of each corrole under the given experimental conditions. Relationships are examined between the experimentally measured logK values and previously published spectroscopic and structural properties of the compounds.

Development of On-Line Monitoring System and Aging Characteristics Research of Switchgear

2013 ◽  
Vol 330 ◽  
pp. 364-367
Author(s):  
Shu Xin Liu ◽  
Yun Dong Cao ◽  
Chun Guang Hou ◽  
Yang Liu ◽  
Xiao Ming Liu
Keyword(s):  
Epoxy Resin ◽  
Monitoring System ◽  
Estimation Method ◽  
Current Transformer ◽  
Insulation Material ◽  
Electrical Characteristics ◽  
Infrared Transmission ◽  
Lifetime Estimation ◽  
Monitoring Method ◽  
On Line

For improving reliable operation of switchgear in power system, an approach for on-line monitoring the insulation characteristic and bus-bar temperature rising of the switchgear is proposed in this paper. Through comparing several existing temperature measurement methods for monitoring temperature rising elevation at bus-bas, a new design of temperature monitoring method is proposed. It adopts quick-magnetic saturated current transformer, temperature sensor and infrared transmission to solve the problem of high voltage isolation. The epoxy resin insulation material which is commonly used in switchgear its aging mechanism data is not complete, seriously restrict on-line monitoring for switchgear, so thousands hours of aging experiment is done on switchgear, systematic study various electrical characteristics variation law on the gradual aging process of epoxy resin insulation materials. Therefore, study on the aging characteristics of switchgearinsulation and its lifetime estimation method is the key technology to understand agingmechanism better, search for new fault diagnostic method and the way to extend theuseful lifetime of switchgear. At last, the system runs in real system and the result shows the on-line monitoring system is stable and reliable which can be provide reference for on-line monitoring system design of switchgear.

scholarly journals Influence of 2,5-dichloro-1,4-benzoquinone on jack bean urease activity. Inhibitory effect, total reducing capacity and DPPH radical scavenging activity.

2011 ◽  
Vol 58 (4) ◽  
Author(s):  
Mirosława Kot ◽  
Zofia Olech
Keyword(s):  
Light Exposure ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Order Rate Constant ◽  
Inhibitory Effect ◽  
Pseudo First Order Reaction ◽  
Experimental Conditions ◽  
Jack Bean ◽  
Direct Modification ◽  
Reducing Capacity

Inhibition of jack bean activity by 2,5-dichloro-1,4-benzoquinone (DCBQ) was studied in phosphate buffer, pH 7.0. It was found that DCBQ acted as a strong, time and concentration dependent inactivator of urease. Under the experimental conditions obeyed the terms of pseudo-first-order reaction, urease was totally inactivated. Application of Wilson-Kitz method proved that the urease-DCBQ interaction followed a simple bimolecular process and the presence of intermediate complex was undetectable. The determined second order rate constant of the inactivation was 0.053 (μM min)(-1). Thiols such as l-cysteine, glutathione and dithiothreitol (DTT) protected urease from inhibition by DCBQ but DCBQ-modified urease did not regain its activity after DTT application. The thiol protective studies indicated an essential role of urease thiol(s) in the inhibition. The irreversibility of the inactivation showed that the process was a result of a direct modification of urease thiol(s) by DCBQ (DCBQ chlorine(s) substitution). The decomposition of DCBQ in aqueous solution at natural light exposure was monitored by visible spectrophotometry, determination of the total reducing capacity (Folin-Ciocalteu method) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging ability. The DCBQ conversion resulted in a decrease of the inhibition power and was well correlated with the increase of the total reducing capacity and DPPH scavenging ability. These findings were attributed to DCBQ transformation by photolysis and the hydrolysis effect was found to be negligible.

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