scholarly journals The determination of the nitrogen-containing ions concentrations dynamics in the oxbow of Ishimchik to assess the impact of 2016–2017 floods

2020 ◽  
Vol 9 (2) ◽  
pp. 98-101
Author(s):  
Anastasia A. Novik ◽  
Aleksey A. Shavnin
Keyword(s):  
Maximum Permissible Concentration ◽  
Main Concern ◽  
Important Indicator ◽  
Water Chemical Composition ◽  
State Study ◽  
High Concentrations ◽  
The Impact ◽  
The Town ◽  
Nitrate Anions

This paper presents the results of the ecological state study of oxbow Ishimchik, located in Ishim, Tyumen Region. The paper presents data on the nitrogen-containing ions concentrations dynamics in water samples of oxbow Ishimchik over the summer-autumn of 2017, the content of which is an important indicator of the water chemical composition. The presence of nitrate ions, nitrite ions and ammonia in high concentrations in the samples usually indicates that the reservoir suffers from contamination by household, agricultural and industrial waste. In 2016 and 2017 a large amount of water from heavy floods came to the oxbow, which could significantly increase the concentration of mineral forms of nitrogen. The main concern is the flood of 2016 as to stop the Ishim private sector flooding a channel was dug for discharge of floodwaters from the town-affected part into the oxbow. To determine the content of nitrogen-containing ions, the photometry method was used. The results of a chemical analysis show that the content of ammonium and ammonia cations (total), nitrite anions and nitrate anions is less than maximum permissible concentration as well as there is a change in the prevailing mineral form of nitrogen from redoxidized to oxidized.

scholarly journals An Interpretable Extreme Gradient Boosting Model to Predict Ash Fusion Temperatures

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 487
Author(s):  
Maciej Rzychoń ◽  
Alina Żogała ◽  
Leokadia Róg
Keyword(s):  
Coefficient Of Determination ◽  
Gradient Boosting ◽  
Important Indicator ◽  
Upper Silesian Coal Basin ◽  
Proposed Model ◽  
Extreme Gradient Boosting ◽  
The Impact ◽  
Partial Dependence ◽  
Individual Input

The hemispherical temperature (HT) is the most important indicator representing ash fusion temperatures (AFTs) in the Polish industry to assess the suitability of coal for combustion as well as gasification purposes. It is important, for safe operation and energy saving, to know or to be able to predict value of this parameter. In this study a non-linear model predicting the HT value, based on ash oxides content for 360 coal samples from the Upper Silesian Coal Basin, was developed. The proposed model was established using the machine learning method—extreme gradient boosting (XGBoost) regressor. An important feature of models based on the XGBoost algorithm is the ability to determine the impact of individual input parameters on the predicted value using the feature importance (FI) technique. This method allowed the determination of ash oxides having the greatest impact on the projected HT. Then, the partial dependence plots (PDP) technique was used to visualize the effect of individual oxides on the predicted value. The results indicate that proposed model could estimate value of HT with high accuracy. The coefficient of determination (R2) of the prediction has reached satisfactory value of 0.88.

Use of an Adjustable Impact Bead in the Analysis of Solutions in Organic Solvents by Flame Atomic Absorption

1992 ◽  
Vol 46 (8) ◽  
pp. 1231-1234 ◽  
Author(s):  
John B. Willis ◽  
Barry T. Sturman
Keyword(s):  
Atomic Absorption ◽  
Organic Solvents ◽  
Simple Technique ◽  
Flame Atomic Absorption ◽  
High Boiling Point ◽  
High Concentrations ◽  
The Impact ◽  
Speed Of Analysis ◽  
Solution Uptake

Throughput of organic solvent aerosol to the flame of an atomic absorption spectrometer may be controlled by varying the position of the impact bead relative to the nebulizer, instead of varying the solution uptake rate of the nebulizer. The usefulness of this simple technique has been demonstrated for a range of elements in three organic solvents (4-methylpentan-2-one, xylene, and a high-boiling-point iso-paraffin solvent), with air/C2H2 and N2O/C2H2 flames. It is shown that the adjustment of the impact bead alone allows the determination of high concentrations of copper and iron in lubricating oils without undue dilution of the sample and can result in significant improvements in the speed of analysis.

scholarly journals The determination of the stability of nitrogen-fixing microorganisms of the soil of Ecuador to toxic metals CrO42–, Ni2+, Cu2+

2018 ◽  
Vol 23 ◽  
pp. 267-272
Author(s):  
O. Yu. Bielikova ◽  
N. A. Matvieieva ◽  
L. S. Yastremskaya ◽  
A. B. Tashyrev
Keyword(s):  
Microbial Communities ◽  
Toxic Metals ◽  
Maximum Permissible Concentration ◽  
Lag Phase ◽  
Nitrogen Fixing ◽  
Natural Ecosystems ◽  
Colony Forming Units ◽  
High Concentrations ◽  
The Stability

Aim. The aim of the work was to determine the stability of nitrogen-fixing microorganisms isolated from the rhizosphere of bromelia (Ecuador), to the effect of toxic metals. Methods. Microorganisms were isolated on the Ashby nutrient medium. The selected strains were cultured on a medium with Cu2+ (Cu (ІІ) citrate) from 50 to 500 mg/l by cation in steps of 50; Ni2+ (NiCl2) from 20 to 200 mg/l by cation in steps of 20; Cr (VI) (K2CrO4) from 20 to 100 mg/l with Cr (VI) in increments of 20. The growth of microorganisms in the presence of metals was characterized by the maximum permissible concentration (MPC) of metals, duration of lag phase and the number of colony-forming units (CFU) of nitrogen-fixing microorganisms with increasing concentration of toxic metals. Results. The selected dominant nitrogen-fixing microorganisms from the soil of Ecuador were resistant to toxic metals (Cu2+, Ni2+, Cr (VI)) in high concentrations. It was found that MPC for microbial communities of nitrogen-fixing microorganisms were: 40 mg/l Cr (VI), 300 mg/l Cu2+ and 100 mg/l Ni2+. Conclusions. It was shown that the selected dominant nitrogen-fixing microorganisms from the Ecuadorian soil were resistant to toxic metals (Cu2+, Ni2+, Cr (VI)) in high concentrations, which in 4–30 times exceed the damage or bactericidal concentrations for the majority of known organophosphate microorganisms of natural ecosystems. Keywords: metalresistance, nitrogen-fixing microorganisms, Cu2+, Ni2+, Cr (VI).

Assessment of sensitivity of the efficiency of regional tax spending towards investment attractiveness of the types of economic activity carried out by the residents of advanced development territory

2020 ◽  
pp. 98-110
Author(s):  
Evgeniya Mikhailovna Popova ◽  
Guzel Mukhtarovna Guseinova ◽  
Sergei Borisovich Milov
Keyword(s):  
Economic Activity ◽  
Socioeconomic Development ◽  
Federal District ◽  
Tax Incentives ◽  
Capital Investments ◽  
The Subject ◽  
Investment Process ◽  
The Impact ◽  
Advanced Development

The deficit of subnational budgets and deceleration capital investments in multiple Russian regions increase the relevance of research aimed at improvement of tax incentivizing practice of the regional investment process. The studies focused on determination of the impact of socioeconomic and institutional factors upon the efficiency of investment tax expenses obtained wide circulation within the foreign scientific literature. The subject of this article is the assessment of sensitivity of the efficiency of regional tax expanses towards investment attractiveness of the types of economic activity carried out by the residents of territories of advanced socioeconomic development, created in the subjects of Far Easter Federal District. The scientific novelty and practical values of this research consists in substantiation of the reasonableness of assessment of investment attractiveness of the types of economic activity that are stimulated by tax incentives. Methodology for assessing investment attractiveness is proposed and tested. The conclusion is made that in case of low investment attractiveness of the type of economic activity, which was planned to support by tax incentives, it is required to conduct and additional analysis to avoid unjustified tax expanses.

Method development for the determination of textural properties of sugar beet roots

2019 ◽  
pp. 392-400 ◽  
Author(s):  
Gunnar Kleuker ◽  
Christa M. Hoffmann
Keyword(s):  
Sugar Beet ◽  
Compression Test ◽  
Storage Period ◽  
Textural Properties ◽  
Small Sample ◽  
Root Tip ◽  
Flexural Test ◽  
Sample Distribution ◽  
The Impact

The harvest of sugar beet leads to root tip breakage and surface damage through mechanical impacts, which increase storage losses. For the determination of textural properties of sugar beet roots with a texture analyzer a reliable method description is missing. This study aimed to evaluate the impact of washing, soil tare, storage period from washing until measurement, sample distribution and number of roots on puncture and compression measurements. For this purpose, in 2017 comprehensive tests were conducted with sugar beet roots grown in a greenhouse. In a second step these tests were carried out with different Beta varieties from a field trial, and in addition, a flexural test was included. Results show that the storage period after washing and the sample distribution had an influence on the puncture and compression strength. It is suggested to wash the roots by hand before the measurement and to determine the strength no later than 48 h after washing. For reliable and comparable results a radial distribution of measurement points around the widest circumference of the root is recommended for the puncture test. The sample position of the compression test had an influence on the compressive strength and therefore, needs to be clearly defined. For the puncture and the compression test it was possible to achieve stable results with a small sample size, but with increasing heterogeneity of the plant stand a higher number of roots is required. The flexural test showed a high variability and is, therefore, not recommended for the analysis of sugar beet textural properties.

Methods for the Determination of the Purity of Exosomes

2020 ◽  
Vol 25 (42) ◽  
pp. 4464-4485 ◽  
Author(s):  
Katarzyna Kluszczyńska ◽  
Liliana Czernek ◽  
Wojciech Cypryk ◽  
Łukasz Pęczek ◽  
Markus Düchler
Keyword(s):  
Drug Transport ◽  
Biological Fluids ◽  
Drug Carriers ◽  
Biological Functions ◽  
Isolation And Purification ◽  
Pubmed Database ◽  
High Concentrations ◽  
Targeted Release

Background: Exosomes open exciting new opportunities for advanced drug transport and targeted release. Furthermore, exosomes may be used for vaccination, immunosuppression or wound healing. To fully utilize their potential as drug carriers or immune-modulatory agents, the optimal purity of exosome preparations is of crucial importance. Methods: Articles describing the isolation and purification of exosomes were retrieved from the PubMed database. Results: Exosomes are often separated from biological fluids containing high concentrations of proteins, lipids and other molecules that keep vesicle purification challenging. A great number of purification protocols have been published, however, their outcome is difficult to compare because the assessment of purity has not been standardized. In this review, we first give an overview of the generation and composition of exosomes, as well as their multifaceted biological functions that stimulated various medical applications. Finally, we describe various methods that have been used to purify small vesicles and to assess the purity of exosome preparations and critically compare the quality of these evaluation protocols. Conclusion: Combinations of various techniques have to be applied to reach the required purity and quality control of exosome preparations.

Identification of N-Substituted Triazolo-azetidines as Novel Antibacterials using pDualrep2 HTS Platform

2019 ◽  
Vol 22 (5) ◽  
pp. 346-354
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Large Scale ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Reporter System ◽  
E Coli ◽  
Starting Point ◽  
High Concentrations ◽  
Mic Value

Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.

Development and Validation of an LC-MS/MS Method for Simultaneous Determination of Canagliflozin and Metformin HCl in Rat Plasma and its Application

2020 ◽  
Vol 16 (6) ◽  
pp. 752-762
Author(s):  
Vivek Nalawade ◽  
Vaibhav A. Dixit ◽  
Amisha Vora ◽  
Himashu Zade
Keyword(s):  
Internal Standard ◽  
Rat Plasma ◽  
Precipitation Method ◽  
Herbal Extracts ◽  
One Step ◽  
Precision And Accuracy ◽  
Development And Validation ◽  
The Impact ◽  
Metformin Hcl

Background: Food and herbal extracts rich in Quercetin (QRT) are often self-medicated by diabetics and can potentially alter the pharmacokinetics (PK) of Metformin HCl (MET) and Canagliflozin (CNG) leading to food or herb-drug interactions and reduced therapeutic efficacy. However, the impact of these flavonoids on the pharmacokinetic behaviour of MET and CNG is mostly unknown. Methods: A simple one-step protein precipitation method was developed for the determination of MET and CNG from rat plasma. The mobile phase chosen was MeOH 65% and 35% water containing 0.1% formic acid at a flow rate of 1mL/min. Results: The retention time of MET, internal standard (Valsartan) and CNG was 1.83, 6.2 and 8.2 min, respectively. The method was found to be linear in the range of 200 - 8000 ng/mL for CNG and 100 = 4000 ng/ml for MET. Precision and accuracy of the method were below 20% at LLOQ and below 15% for LQC, MQC, and HQC. Conclusion: The method was successfully applied for the determination of PK of MET and CNG by using 100 μL of rat plasma. QRT co-administration affects the PK parameters of MET and CNG. This alteration in PK parameters might be of significant use for clinicians and patients.

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