scholarly journals THE FERRIC FERRICYANIDE REDUCTION TEST IN HISTOCHEMISTRY

1953 ◽  
Vol 1 (2) ◽  
pp. 87-92 ◽  
Author(s):  
R. D. LILLIE ◽  
HELEN J. BURTNER

Ascorbic, oxalic and uric acids, phenols, indols, pyrrols, aryl amines, hydrazines, thiols and inorganic sulfides and peroxide promptly reduce ferric ferricyanide mixtures to Prussian blue. Most of the other substances tested reacted feebly or slowly, and probably need not be considered in the histochemical test, provided the reaction time is kept down to 10 to 15 minutes.

Author(s):  
Yuichi Suzuki

Abstract A subtest of the LLAMA test battery (LLAMA_D) has been proposed as a potential test of implicit learning aptitude. To improve its construct validity, in the present study, the original LLAMA_D (a) instructions for incidental learning were modified, and (b) confidence ratings of test responses and (c) reaction time (RT) measurements were added. This revised LLAMA_D was administered along with the other LLAMA subtests (LLAMA-B, -E, and -F). Unconscious knowledge that may (not) result from the exposure was assessed through the relationship between the accuracy/RT and confidence ratings. The results suggest that LLAMA_D accuracy largely reflects conscious retrieval of previously heard sound sequences. However, an index derived from the LLAMA_D RT measure (coefficient of variance) was associated with an aspect of oral fluency, which is presumably dependent on proceduralization. Several recommendations are proposed to redesign and extend LLAMA_D as a potential aptitude test for proceduralization.


2010 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Murillo ◽  
J. Sarasa ◽  
M. Lanao ◽  
J. L. Ovelleiro

The degradation of chlorpyriphos by different advanced oxidation processes such as photo-Fenton, TiO2, TiO2/H2O2, O3 and O3/H2O2 was investigated. The photo-Fenton and TiO2 processes were optimized using a solar chamber as light source. The optimum dosages of the photo-Fenton treatment were: [H2O2]=0.01 M; [Fe3 + ]=10 mg l−1; initial pH = 3.5. With these optimum conditions total degradation was observed after 15 minutes of reaction time. The application of sunlight was also efficient as total degradation was achieved after 60 minutes. The optimum dosage using only TiO2 as catalyst was 1,000 mg l−1, obtaining the maximum degradation at 20 minutes of reaction time. On the other hand, the addition of 0.02 M of H2O2 to a lower dosage of TiO2 (10 mg l−1) provides the same degradation. The ozonation treatment achieved complete degradation at 30 minutes of reaction time. On the other hand, it was observed that the degradation was faster by adding H2O2 (H2O2/O3 molar ratio = 0.5). In this case, total degradation was observed after 20 minutes.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Pradeep Paliwal ◽  
Srinivasa Rao Jetti ◽  
Anjna Bhatewara ◽  
Tanuja Kadre ◽  
Shubha Jain

The reaction of 5,5-dimethylcyclohexane-1,3-dione with various heteroarylaldehydes afforded the corresponding heteroaryl substituted xanthene derivatives 1(a–f). The reaction proceeds via the initial Knoevenagel, subsequent Michael, and final heterocyclization reactions using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a catalyst in aqueous media. The synthesized heteroaryl substituted xanthenes 1(a–f) reacted with malononitrile to obtain different alkylidenes 2(a–f). Short reaction time, environmentally friendly procedure, avoiding of cumbersome apparatus, and excellent yields are the main advantages of this procedure which makes it more economic than the other conventional methods.


1947 ◽  
Vol s3-88 (4) ◽  
pp. 467-478
Author(s):  
A. J. CAIN

1. Baker's acid haematein test for phospholipines is specific provided that only a definite positively result is considered. Very pale blues and greys may be caused by other lipoids, which if present in very large masses may possibly show medium to dark blue granules but will not be coloured all through. 2. The mechanism of the test appears to be as follows: (a) Phospholipine is not fixed by formal-calcium but is restrained from passing into solution by the calcium ions, which play no other part. (b) Phospholipine combines readily with chromium from the mordanting fluid, and is then rendered insoluble and mordanted. Other substances, acidic and usually containing phosphorus, are mordanted as well. (c) On staining, blue and brown colorations are formed; in both cases the dye attaches itself to the chromium in the various substrates. (d) On differentiation, some browns and most blues, particularly those with phosphoric substrates, remain nearly fast, but most browns and the weak blues of certain lipoids (not phospholipines) are greatly reduced or removed entirely. The period of differentiation must not be shortened. (e) Blue-staining lipoids (phospholipines) are distinguished from other blue-staining substances by an extraction with the lipoid solvent pyridine, after special fixation. The other substances, and any bound lipoid not removable with pyridine, remain. 3. Since the specificity of the test depends on the relatively greater affinity of phospholipines among lipoids for the mordant, the period of chroming must not be lengthened. 4. One reason why some substances are coloured after pyridine extraction but not after acid haematein is that in the former case they are precipitated and so concentrated; in the latter they are not. This is not a general explanation for the whole class of such substances.


1993 ◽  
Vol 2 (5) ◽  
pp. 429-436 ◽  
Author(s):  
Jean-Pierre Hallé ◽  
Danielle Landry ◽  
Alain Fournier ◽  
Michèle Beaudry ◽  
Francois A. Leblond

Alginate is a key reagent in the preparation of microcapsules for cell transplantation. To address the question of the intracapsular alginate concentration, a sensitive assay has been developed to quantify the alginate content of microcapsules. The method is based on the metachromatic change induced by alginate binding to the dye, 1,9-dimethyl methylene blue (DMMB). The assay has a high sensitivity and precision. It covers a wide concentration range enabling the measurement of alginate in dilute supernatants as well as in microcapsules. For the latter, the membrane is initially dissolved by incubating the microcapsules in an alkaline medium. The effect of potentially interfering substances (poly-l-lysine (PLL), citrate, chloride, sodium) and of pH has been studied. Poly-l-lysine interfered with the assay at pH 6.5 but not at pH 13. Interference by sodium augmented with increasing sodium concentration and reached a plateau at 200 mM. This problem was overcome by routinely adjusting all samples to 500 mM sodium. The other substances tested had a negligible effect on the assay. The reliable measurement of alginate with this new assay will allow the optimization of the intracapsular alginate concentration.


2019 ◽  
Vol 10 (3) ◽  
pp. 1961-1969
Author(s):  
Talal Aburjai ◽  
Rudaina Othman Yousif ◽  
Mahmood Jasim AlSamydai ◽  
Ali Al-Samydai ◽  
Farah Al-Mamoori ◽  
...  

The consumption of dietary supplements has nowadays become popular, especially in Jordanian sports clubs and gyms. In fact, there is a widespread idea, among consumers, that these proteins contain hormones in order to increase their efficiency. The objective of this study is to develop a better understanding of customer opinion in an era that increased growth in Jordan and improves a chromatographic method to detect the testosterone in protein supplements. The method of this study, six popular types of proteins in the Jordan market have been chosen after conducting a primary study of the proteins' users by questionnaires to identify their opinions about these proteins. These proteins have been analyzed by reverse-phase high-performance liquid chromatography by developing an easy and fast method to detect testosterone signal between 8-9 minutes of the chromatogram. The results of the study showed that 61% of the users believe that sport proteins contain hormones and other substances that are not mentioned in the list of ingredients. While 39% believe otherwise. On the other side, HPLC results of six proteins showed no signs for testosterone hormone. The main reason that drives them to take sport proteins is for building muscles in spite of they believe it could be harmful due to containing hormones and other substances. So in future investigations, it might be possible to use different brands and investigate them by using the same method.


2018 ◽  
Vol 11 (1) ◽  
pp. 69-77
Author(s):  
Fabrizio Perroni ◽  
Eric Mol ◽  
Anthony Walker ◽  
Calogero Alaimo ◽  
Laura Guidetti ◽  
...  

Background: In order to stay safe, and to successfully complete their work, firefighters have to constantly assess and process large numbers of sensory stimuli and adapt to the inherent risks present in the working environment. Objective: The purposes of the present preliminary study were to analyse the speed of Reaction Time responses (RT) of Italian Firefighters and to compare their cognitive responses with non-firefighting subjects. Methods: Anthropometric (weight, height and BMI) and RT (time-to-completion –TTC-, mean of reaction time –MRT-, and errors made -E-) evaluations were administered at 16 volunteers (Age: 40.3 ± 6.7 yrs; BMI: 23.8 ± 2.3 kg/m2) divided in Firefighters (FG) and Control (CG) groups. RT test consisted of 3 trials (T1 = 1s of stimulus duration and 1s interval between stimulus and the other; T2 = 0.5s of stimulus duration and 1s interval between stimulus and the other; T3 = 0.5s of stimulus duration and 0.5s interval between stimulus and the other). Mann Whitney U test between groups was applied to asses differences (p ≤ 0.05) in TTC, MRT, and E while Friedmann test and Dunn-Sidak post hoc were used to evaluate significant differences in the 3 trials in each variable of each group. Results: No significant differences based on anthropometric parameters were observed between groups. Despite no significant differences emerged for TTC and MRT between groups, we observed significant differences in E between groups (CG = 4; FG =12) and in the 3rd condition in each variable of each group. Conclusion: Workout programs that integrate reaction time training with job performance should be created to increase job performance.


1974 ◽  
Vol 38 (2) ◽  
pp. 417-418 ◽  
Author(s):  
Robert Zenhausern ◽  
Claude Pompo ◽  
Michael Ciaiola

Simple and complex reaction time to visual stimuli was tested under 7 levels of accessory stimulation (white noise). Only the highest level of stimulation (70 db above threshold) lowered reaction time. The other levels had no effect.


2003 ◽  
Vol 29 (3) ◽  
Author(s):  
Johann M. Schepers ◽  
Paul Potter ◽  
Christo Van Niekerk

The principal objective of the study was to examine the effect of Telfast® 180, an antihistamine, on driver behaviour, decision-making, and reaction time. A sample of 255 volunteers participated in the study. The sample was randomly divided into two groups, viz. a placebo and a Telfast group. One of the groups received Telfast and the other a placebo. Initially all the participants were given a standardised driving test, as well as a psychomotor test. Immediately thereafter the placebo group received their placebo tablets and the Telfast group their Telfast tablets. Exactly 2,6 hours later every participant was tested again, using the same tests as before. No statistically significant differences were found between the Placebo group and the Telfast group. No sedative effects due to Telfast® 180 were thus evident. Opsomming Die hoofdoelstelling van die studie was om die effek van Telfast® 180, ’n antihistamien, op bestuursgedrag, besluitneming en reaksietyd, te ondersoek. ’n Steekproef van 255 vrywilligers het aan die studie deelgeneem. Die steekproef is lukraak in twee groepe verdeel, te wete ‘n plasebogroep en ’n Telfastgroep. Om mee te begin is al die deelnemers aan ’n gestandaardiseerde bestuurstoets, asook ’n psigomotoriese toets, onderwerp. Onmiddellik daarna het die plasebogroep hul plasebotablette en die Telfastgroep hul Telfasttablette ontvang. Presies 2,6 uur later is al die deelnemers weer getoets met dieselfde toetse as voorheen. Geen statisties beduidende verskille is tussen die plasebogroep en die Telfastgroep gevind nie. Daar was dus geen sedatiewe effek as gevolg van Telfast® 180 nie.


2015 ◽  
Vol 724 ◽  
pp. 53-56
Author(s):  
Qin Zhang ◽  
Lin Li ◽  
You Mo

The housing construction grouting technique is to select a specific pressure feed approach to pour the slurry in gel into the loose soil or the rock cracks with water. The slurry, through condensation and the particles consolidation in this category, will be filled into the rock cracks in the section so as to improve the inherent nature of the soil and the mechanical properties of the other substances. During the construction period, the slurry can be fed into the injected holes within this segment through the unique role of the pressure. The small opening surrounding the grouting holes, the preset requirements will be met. Therefore, it is necessary to clarify the specific applications of grouting techniques.


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