scholarly journals Determination of Cu and Pb concentrations based on urease activity inhibition of Durio zibethinus L. seeds

Molekul ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 92
Author(s):  
Zusfahair Zusfahair ◽  
Amin Fatoni ◽  
Dian Riana Ningsih ◽  
Anung Riapanitra
Keyword(s):  
Urease Activity ◽  
Atomic Absorption Spectrophotometry ◽  
Urea Concentration ◽  
Activity Inhibition ◽  
Durio Zibethinus ◽  
Significant Difference ◽  
Standard Solution ◽  
Urease Inhibitory ◽  
Pb Concentration

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.

Atomic Absorption Spectrophotometric Determination of 4-Hydroxy-3-Nitrobenzenearsonic Acid (Roxarsone) in Premixes

1975 ◽  
Vol 58 (5) ◽  
pp. 945-948 ◽  
Author(s):  
Larry J Frahm ◽  
Marven E Albrecht ◽  
J Patrick Mcdonnell
Keyword(s):  
Atomic Absorption ◽  
Ammonium Carbonate ◽  
Atomic Absorption Spectrophotometry ◽  
Electrodeless Discharge ◽  
Absorption Spectrophotometry ◽  
Coefficients Of Variation ◽  
Instrument Response ◽  
Variation Range ◽  
Standard Solution

Abstract Roxarsone (4-hydroxy-3-nitrobenzenearsonic acid) is extracted from the premix with aqueous 1% ammonium carbonate. The extract is filtered, diluted, and analyzed by atomic absorption spectrophotometry, using an air-acetylene flame and an arsenic electrodeless discharge lamp. The instrument response of the sample is compared to that of a standard solution of arsenic trioxide. Recoveries range from 99.7 to 100.4% and coefficients of variation range from 0.35 to 0.63%.

Online Monitoring of Trace Copper (II) in Environmental Waters

2012 ◽  
Vol 599 ◽  
pp. 188-191
Author(s):  
Liang Wei ◽  
Yi Chun Dai
Keyword(s):  
Online Monitoring ◽  
Atomic Absorption Spectrophotometry ◽  
Neutral Red ◽  
Environmental Waters ◽  
Experimental Conditions ◽  
Standard Curve ◽  
Relative Standard ◽  
Standard Solution ◽  
Catalytic Spectrophotometry

Based on the fact that copper can catalyze the fading reaction of neutral red reduced by hydrogen peroxide using the alanine as a sensitizer in NH4Cl-NH3•H2O medium (pH 8.0), a method was developed for online monitoring of trace copper in environmental waters by flow injection catalytic spectrophotometry. The experimental conditions were optimized. Under optimum conditions, the linear range of the proposed method was between 1.0 µg/L to 125 µg/L and the correlation coefficient of standard curve was 0.9995. The detection limit of the proposed method was 0.11 µg/L. The relative standard deviation of 2.7% and 1.5% was obtained by injecting 15.00 µg/L and 100.00 µg/L copper of standard solution respectively (n=8). The proposed method had been applied to determination of trace amounts of copper in environmental waters. The results were in good agreement with those obtained by atomic absorption spectrophotometry (AAS)

scholarly journals Determination of Heavy Metals in Surface Water, Sediments and Planktons at the Junction of Multiple Rivers (Punjnad Headworks) and Their Impact on Human Health

2021 ◽  
Author(s):  
Saima Naz ◽  
Borhan Mansouri ◽  
Ahmad Manan Mustafa Chatha ◽  
Qudrat Ullah ◽  
Zain Ul Abadeen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Surface Water ◽  
Human Health ◽  
Metal Concentrations ◽  
Bed Sediments ◽  
Heavy Metal Concentrations ◽  
Significant Difference ◽  
Pb Concentration

Abstract This study was conducted to calculate the burden of heavy metals i.e., aluminium (Al), arsenic (As), barium (Ba) and lead (Pb) in the river water of Punjnad Headworks, Bahawalpur, Pakistan. For this purpose, samples were collected from surface water, bed sediments and planktons during autumn, winter and spring seasons (September 2018 to May 2019). The results showed that in surface water Pb concentration was highest (453.87 mg L-1), while in sediments and plankton, Al concentration was highest (370.24 µg g-1 and 315.05 µg g-1, respectively). A significant difference (p < 0.000) in metal concentrations was found among surface water, bed sediments and plankton at different sampling stations during various seasons. However, findings of this study showed no adverse effects of heavy metal concentrations on human health. This study provided better understanding of various pollutants and their concentrations in water sources at the studied location.

scholarly journals Quality control of full-fat soybean using urease activity: Critical assessment of the method

2008 ◽  
pp. 47-53 ◽  
Author(s):  
Dragan Palic ◽  
Jovanka Levic ◽  
Slavica Sredanovic ◽  
Olivera Djuragic
Keyword(s):  
Quality Control ◽  
Difference Method ◽  
Urease Activity ◽  
Critical Assessment ◽  
Reliable Indicator ◽  
Significant Difference

A critical assessment of the method for determination of urease activity, as an indicator of the degree of full-fat soybean (FFSB) processing, has been undertaken. FFSB was processed by dry extrusion at five temperatures, ranging from 115?C to 165?C, and analyzed for urease activity by two laboratories and by two analysts at each laboratory, using the pH-difference procedure. The in vivo trial with chickens fed the processed FFSB has also been conducted. While the results of two analysts at each laboratory did not differ significantly (P>0.05), there was a significant difference (P<0.05) in urease activity results between the two laboratories. The overall conclusion of this study is that the urease activity determined by pH-difference method can not be recommended as a reliable indicator for FFSB quality control.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

Determination of the prevalence of helicobacter pylori oral infection in smoking patients with chronic generalized periodontitis on the background of chronic hyperacidal gastritis during treatment

2020 ◽  
Vol 40 (4) ◽  
pp. 50-54
Author(s):  
O. L. Zolotukhina ◽  
◽  
Ju. G. Romanova ◽  
O. V. Maslov ◽  
◽  
...  
Keyword(s):  
Risk Factors ◽  
Helicobacter Pylori ◽  
Oral Cavity ◽  
Urease Activity ◽  
Rapid Test ◽  
Oral Infection ◽  
Helicobacter Pylori Infection ◽  
Natural Origin ◽  
Periodontal Tissues

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.

scholarly journals Determination of vertical dimension of occlusion by using the phonetic vowel "O" and "E"

2015 ◽  
Vol 72 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Marko Igic ◽  
Nebojsa Krunic ◽  
Ljiljana Aleksov ◽  
Milena Kostic ◽  
Aleksandra Igic ◽  
...  
Keyword(s):  
Cognitive Functions ◽  
Complete Denture ◽  
Reference Points ◽  
Vertical Dimension ◽  
Entire Sample ◽  
Average Value ◽  
Significant Difference ◽  
The Relationship

Background/Aim. The vertical dimension of occlusion is a very important parameter for proper reconstruction of the relationship between the jaws. The literature describes many methods for its finding, from the simple, easily applicable clinically, to quite complicated, with the use of one or more devices for determination. The aim of this study was to examine the possibility of determining the vertical dimension of occlusion using the vocals ?O? and ?E? with the control of values o btained by applying cognitive functions. Methods. This investigation was performed with the two groups of patients. The first group consisted of 50 females and 50 males, aged 18 to 30 years. In this group the distance between the reference points (on top of the nose and chin) was measured in the position of the mandible in the vertical dimension of occlusion, the vertical dimension at rest and the pronunciation of the words ?OLO? and ?ELE?. Checking the correctness of the particular value for the word ?OLO? was also performed by the phonetic method with the application of cognitive exercises when the patients counted from 89 to 80. The obtained difference in the average values i n determining the vertical dimension of occlusion and the ?OLO? and ?ELE? in the first group was used as the reference for determining the vertical dimension of occlusion in the second group of patients. The second group comprised of 31 edentulous persons (14 females and 17 males), aged from 54 to 85 years who had been made a complete denture. Results. The average value obtained for the vertical dimension of rest for the entire sample was 2.16 mm, for the word ?OLO? for the entire sample was 5.51 mm and for the word ?ELE? for the entire sample was 7.47 mm. There was no statistically significant difference between the genders for the value of the vertical dimension at rest, ?ELE? and ?OLO?. There was a statistically significant difference between the values f or the vertical dimension at rest, ?OLO? and ?ELE? for both genders. There was a statistically significant correlation between the value for the vertical dimension at rest, ?OLO? and ?ELE?, for both groups of subjects. Conclusion. Determining the vertical dimension of occlusion requires 5.5 mm subtraction from the position of the mandible in pronunciation of the word ?OLO? or 7.5 mm in pronunciation of the word ?ELE?.

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