scholarly journals A Dip-and-Read Test Strip for the Determination of Mercury(II) Ion in Aqueous Samples Based on Urease Activity Inhibition.

2002 ◽  
Vol 18 (11) ◽  
pp. 1215-1219 ◽  
Author(s):  
Guo-qing SHI ◽  
Guibin JIANG
Molekul ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 92
Author(s):  
Zusfahair Zusfahair ◽  
Amin Fatoni ◽  
Dian Riana Ningsih ◽  
Anung Riapanitra

The determination of heavy metal concentrations has been carried out using sophisticated instruments, and therefore a simple and reliable alternative method is needed as a comparison. The study aimed to determine Cu and Pb concentration of standard solution using the urease activity inhibition method of Durio zibethinus L.  seeds.  The research started with urease extraction from Durio D. zibethinus L. seeds. The activity of the obtained extract was determined using the Nessler method. The optimum substrate concentration was also determined. Urease activity inhibition was carried out using various metal solution concentrations, which continued by plotting a log graph of urea concentration vs. %inhibition. The obtained graph would then determine the metal concentration in a synthetic water sample. The data was then compared to the measurement, determined by the Atomic Absorption Spectrophotometry (AAS) method. Results of the study showed that the urease activity of D. zibethinus L.seeds was 296.774 U/mL. Urease activity was optimum at a urea concentration of 0.3 M. The comparison Cu, and Pb concentration determination using the urease inhibitory activity and AAS methods showed no significant difference at 95% confidence level. This research showed that urease of D. zibethinus L. seed could be used to determine Cu and Pb's concentration based on its inhibiting activity.


Author(s):  
O. L. Zolotukhina ◽  
◽  
Ju. G. Romanova ◽  
O. V. Maslov ◽  
◽  
...  

Diseases of periodontal tissues occupy one of the leading positions among modern dental problems, namely the multifactorial nature of these diseases. In modern dental science, the issue of the development of periodontal pathology against the background of somatic pathology and risk factors remains relevant. Pathology of periodontal tissues in 68–90 % of cases is accompanied by chronic diseases of the gastrointestinal tract. Today, there is no doubt that Helicobacter pylori infection can be present in the biotopes of the oral cavity and can affect the course of periodontal pathology. As you know, smoking is one of the important risk factors for the development of inflammatory-dystrophic diseases of periodontal tissues, which can aggravate the course of the latter. The purpose of the work is to determine the prevalence of oral Helicobacter pylori infection in tobacco-dependent patients with chronic generalized periodontitis on the background of chronic hyperacid gastritis during treatment. Patients who received the proposed therapeutic and prophylactic complex (ultraphonophoresis procedures with the created gel «Apisan», and probiotic drug BioGaia ProDentis and angioprotective drug of natural origin — Detralex) showed a gradual decrease in the level of total urease activity and, as a consequence, a decrease the prevalence of Helicobacter pylori infection in the oral cavity according to the results of a urease rapid test with material from the oral cavity, both in the presence of a risk factor — smoking, and in its absence. The use of the proposed therapeutic and prophylactic complex proved to be effective in reducing the prevalence of oral Helicobacter pylori infection in smoking patients and patients who do not smoke, with chronic generalized periodontitis against the background of chronic hyperacidal gastritis associated with Helicobacter pylori.


2010 ◽  
Vol 75 (5) ◽  
pp. 563-575 ◽  
Author(s):  
Moslem Mohammadi ◽  
Mehdi Khodadadian ◽  
Mohammad K. Rofouei

A plasticized poly(vinyl chloride) membrane electrode based on 4-[(5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl]benzene-1,3-diol (L) for highly selective determination of palladium(II) (in PdCl42– form) is developed. The electrode showed a good Nernstian response (29.6 ± 0.4 mV per decade) over a wide concentration range (3.1 × 10–7 to 1.0 × 10–2 mol l–1). The limit of detection was 1.5 × 10–7 mol l–1. The electrode has a response time of about 20 s, and it can be used for at least 2 months without observing any considerable deviation from Nernstian response. The proposed electrode could be used in the pH range of 2.5–5.5. The practical utility of the electrode has been demonstrated by its use for the estimation of palladium content in aqueous samples.


The Analyst ◽  
1997 ◽  
Vol 122 (9) ◽  
pp. 889-894 ◽  
Author(s):  
René B. Geerdink ◽  
Sylvia van Tol-Wildenburg ◽  
Wilfried M. A. Niessen ◽  
Udo A. Th. Brinkman

1999 ◽  
Vol 50 (3) ◽  
pp. 579-583 ◽  
Author(s):  
Phillip E Warwick ◽  
Ian W Croudace ◽  
Alison A Dale

1995 ◽  
Vol 32 (9) ◽  
pp. 369 ◽  
Author(s):  
Tarasankar Pal ◽  
Nikhil R. Jana ◽  
Tapankumar Sau

2009 ◽  
Vol 38 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Clàudia Fontàs ◽  
Eva Marguí ◽  
Manuela Hidalgo ◽  
Ignasi Queralt
Keyword(s):  

2014 ◽  
Vol 6 (4) ◽  
pp. 1254 ◽  
Author(s):  
J. S. Crosby ◽  
J. Z. James ◽  
D. Lucas ◽  
C. P. Koshland

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