reference concentration
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2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Pengyi Li ◽  
Lianbing Gu ◽  
Jing Tan ◽  
Zhenghuan Song ◽  
Qingming Bian ◽  
...  

Abstract Background Prostaglandin E1 (PGE1) has been reported to maintain adequate oxygenation among patients under 60% FiO2 one-lung ventilation (OLV). This research aimed to explore whether PGE1 is safe in pulmonary shunt and oxygenation under 40% FiO2 OLV and provide a reference concentration of PGE1. Methods Totally 90 esophageal cancer patients treated with thoracotomy were enrolled in this study, randomly divided into three groups (n = 30/group): Group A (60% FiO2 and 0.1 µg/kg PGE1), Group B (40% FiO2 and 0.1 µg/kg PGE1), and Group C (40% FiO2, 0.2 µg/kg PGE1). Primary outcomes were oxygenation and pulmonary shunt during OLV. Secondary outcomes included oxidative stress after OLV. Results During OLV, patients in Group C and B had lower levels of PaO2, SaO2, SpO2, MAP, and Qs/Qt than those in Group A (P < 0.05). At T2 (OLV 10 min), patients in Group C and B exhibited a lower level of PaO2/FiO2 than those in Group A, without any statistical difference at other time points. The IL-6 levels of patients in different groups were different at T8 (F = 3.431, P = 0.038), with IL-6 in Group C being lower than that in Group B and A. MDA levels among the three groups differed at T5 (F = 4.692, P = 0.012) and T7 (F = 5.906, P = 0.004), with the MDA level of Group C being lower than that of Group B and A at T5, and the MDA level of Group C and B being lower than that of Group A at T7. In terms of TNF-α level, patients in Group C had a lower level than those in Group B and A at T8 (F = 3.598, P = 0.033). Compared with patients who did not use PGE1, patients in Group C had comparable complications and lung infection scores. Conclusion The concentration of FiO2 could be reduced from 60 to 40% to maintain oxygenation. 40% FiO2 + 0.2 µg/kg PGE1 is recommended as a better combination on account of its effects on the inflammatory factors. Trial registration: Chictr.org.cn identifier: ChiCTR1800018288, 09/09/2018.


2021 ◽  
pp. 42-49
Author(s):  
P.Z. Shur ◽  
◽  
N.V. Zaitseva ◽  
А.А. Khasanova ◽  
К.V. Chetverkina ◽  
...  

Recently multiple new toxicological and epidemiologic data on negative effects produced by chemicals have become available; given that, it is necessary to improve quantitative criteria applied in health risk assessment. It is advisable to revise previously established reference concentrations and to make more precise lists of organs and systems affected by a chemical in concentrations which are either equal to reference one or exceed it. Our research aim was to establish a reference concentration for benzene and additional quantitative indicators of its effects (additional reference concentrations) on specific organs and systems under chronic inhalation exposure; another aim was to determine average annual MPC verified as per permissible lifetime carcinogenic risk using evolution models. The research allowed recommending 0.005 mg/m3 to be used as a reference concentration under chronic inhalation exposure to benzene; a decrease in quantity of B-lymphocytes was recommended as a critical effect since this decrease might produce negative effects on the blood and immune system. Additional reference concen-trations for benzene were fixed at 0.007 mg/m3 for the liver as a critical organ and 0.012 mg/mg3 for violated process of organism development as a critical effect. They can be used as additional indicators for assessing non-carcinogenic health risks under chronic inhalation exposure to benzene in its elevated concentrations. Our research results were used to substantiate average annual MPC for benzene in ambient air; its recommended value was 0.005 mg/m3 since it provided safety (absence of impermis-sible (unacceptable) lifetime health risk), probable carcinogenic effects taken into account.


2021 ◽  
Author(s):  
Ricardo H. Deucher ◽  
Hamdi A. Tchelepi

Abstract Subsurface sequestration of carbon dioxide, contaminant transport, and enhanced oil recovery processes often involve complex reaction dynamics. The rock-fluid interactions span a very wide range of length and time scales, and it is important for the numerical solutions to resolve these scales properly. To address these challenges, we extend the adaptive transport scheme for the simulation of reactive transport in heterogeneous porous media developed previously (Deucher and Tchelepi, 2021) to account for (a) higher-order approximation of the convective fluxes and (b) coupling with a chemical solver connected to geochemical databases. The numerical results demonstrate that adaptivity is more effective when a higher-order approximation of the fluxes is used. This is because of lower levels of numerical dispersion compared with low-order approximations, which helps resolve the displacement fronts more accurately. As a result, the regions that experience significant concentration and saturation gradients are more confined, and that leads to improvements in the computational efficiency of the adaptive scheme. The robustness of the approach is demonstrated using a highly heterogeneous two-phase case with multiple wells and a variable total liquid-rate. Due to the modularity of the adaptive scheme, coupling with a chemical solver module is straightforward. The scheme is tested for a three-dimensional case that considers injection of carbonated water in a reservoir matrix of calcite. The results show that the adaptive scheme leads to an accurate representation of the reference concentration distributions of the six reactive components throughout the simulation and leads to a large reduction in the number of cell updates required to achieve the solution.


Mining Revue ◽  
2021 ◽  
Vol 27 (3) ◽  
pp. 1-16
Author(s):  
Alexandru Simion ◽  
Carsten Drebenstedt ◽  
Maria Lazăr

Abstract Analysing environmental impacts of mining activities involves detailed studies of the interactions between technological activities/operations carried out in a mining operation and environmental components affected by them. In order to carry out a more complex environmental impact assessment caused by mining in the eastern part of Jiu Valley on soil and water 4 mining units have been considered in the study, these being mining unit Lonea, Petrila, and Livezeni with their belonging dumps. Main objective of this research is to analyse the impact caused by mining activities in Eastern part of Jiu Valley by the method of impact networks according to the model “causes - pressures, depreciation of the quality of environmental factors – affected parameters - impact”. Thus, impacts caused by the mining industry were identified based on the top-down typology, being shaped impact networks for underground coal exploitation and sterile material storage on the surface. The metal content of the dumps was also analysed in order to assess the degree of metals soil enrichment compared to the reference concentration of a blank sample. The analysis of the influence of the local rainfall regime aims to highlight the leaching potential of heavy metals in the body of the dump and the possibility of analysing the scenarios of extension of the pollution phenomenon to the saturated area. The study is addressed to researchers, environmental engineers, hydrogeologists and geologists who want to deepen the study of transfer mechanisms of contaminants from dumps to watercourses receiving areas and their dispersion in unsaturated and saturated areas.


OENO One ◽  
2021 ◽  
Vol 55 (2) ◽  
pp. 47-55
Author(s):  
Chiara Nadai ◽  
Alessio Giacomini ◽  
Viviana Corich

Starmerella bacillaris is a non-Saccharomyces yeast recently proposed for grape fermentation in association with Saccharomyces cerevisiae. Due to its high glycerol and moderate volatile acidity production this yeast can contribute to improving wine quality. Some strains have been demonstrated to exhibit antifungal activity against grey mould on grape, which is caused by Botrytis cinerea. The simultaneous presence of these traits in S. bacillaris is of great interest. Indeed, this yeast can be potentially used as a biocontrol agent in vineyards. Research on the ability of S. bacillaris to survive or, even to grow on the surface of grapes is a starting point in the evaluatation of its potential use in vineyards. The preliminary results of our study showed that when applied to the grape surface under laboratory condictions, inoculum sized S. bacillaris with antifungal activity developed and lasted for at least 6 days in high concentrations. In addition, it positively influenced the fermentation process by producing high concentrations of glycerol (average value 4.89 ± 0.47 g/L). Interestingly, a positive effect on wine quality was also observed when the inoculum size was 10 times higher or lower than the reference concentration. When sprayed on the vines in the vineyard and present on the grape skin surface after harvest, S. bacillaris cells can start alcoholic fermentation.


2021 ◽  
Vol 15 (2) ◽  
pp. 115-120
Author(s):  
Mustafa Özgür ◽  
◽  
Şemsi Gül Yılmaz ◽  
Ash Uçar ◽  
Serkan Yılmaz ◽  
...  

Background: Endocrine compounds, such as Bisphenol A (BPA), stimulate or inhibit the activities of hormones, nuclear receptors in the central nervous system, liver and other organs. They may be disposed of in the environment inadverdently around industrial sites. The aim of this study was to evaluate the cytotoxic effects of BPA on human lymphocytes in culture at varying concentrations. Methods: 0.1 mL heparinized 0.2 mL peripheral blood taken from a healthy male and a female were plated in culture media under sterile conditions. To prepare the reference dose at a concentration of 0.05 mg/mL, 0.027g BPA was dissolved in 1 L dimethyl sulfoxide and the highest dose of 50 μg/mL BPA solution was prepared. After separating the stock solution, 50 μg/mL BPA was diluted to prepare 20, 10 or 5 μg/mL doses. Results: After 24 h of incubation, abnormal cell±Standart Error (%)[AC±SE (%)] 1.10±1.0, chromosomal aberration/cell±Standart Error (CA/cell±SE) 0.025±0.01 was determined in control group, and AC±SE (%) 2.00±0.98 in control group. After 48 h of incubation 0.98, CA/cell±SE was found to be 0.020±0.01. After 24 and 48 h of incubation, AC±SE (%) and CA/cell±SE ratios were 30.00±3.24, 34.00±3.35 and 0.325±0.03, 0.430±0.04, respectively. Conclusion: The cytotoxic effect of BPA on human lymphocytes was investigated in this study at reference concentration and lower doses. Our findings support the fact that BPA substitutes may not be sufficiently safe for widespread use as industrial chemicals.


2021 ◽  
Vol 36 (3) ◽  
pp. 233-237
Author(s):  
Marek Dziadosz ◽  
Katarina Bolte ◽  
Wolfgang Rosenberger ◽  
Michael Klintschar ◽  
Jörg Teske

Abstract Objectives Since melperone abuse with lethal intoxication is common, expert opinions based on therapeutical and lethal concentration ranges can be considered as important. Because there is a lack of information about fatalities caused by melperone mono-intoxications and data on tissue samples with concentration distribution, the aim of this work is the examination of lethal concentration ranges of melperone and drug quantification in different matrices. Methods An LC-MS/MS method was applied for analyses performed in blood and tissue samples. Quantification based on standard addition and sample preparation on liquid–liquid extraction with 1-chlorobutane. An appropriate tissue homogenization was performed ahead of extraction with an IKA Ultra-Turrax-Tube-Drive®. A Luna 5 µm C18 (2) 100 Å, 150  × 2 mm analytical column was used for chromatographic separation and the elution was performed with two mobile phases consisted of A (H2O/methanol = 95/5, v/v) and B (H2O/methanol = 3/97, v/v) both with 10 mM ammonium acetate and 0.1% acetic acid. Results A multi-drug LC-MS/MS analytical method developed was applied successfully for melperone quantification in different post-mortem matrices. No analytical problems could be identified during method development and analyses of real samples. The melperone lethal concentration calculated in femoral blood of the drug mono-intoxication investigated was 10 mg/L. Melperone concentration distribution was presented for the first time. Conclusions The lethal reference concentration of melperone in femoral blood of 17.1 mg/L pointed out in different reference lists should be used with caution. Instead, a lower lethal melperone concentration should be considered. The post-mortem concentration distribution of the drug presented could be helpful in the interpretation of cases where no blood samples are available.


2021 ◽  
Author(s):  
Georgia E. Guild ◽  
James C. R. Stangoulis

Abstract Background and aims This study explores the use of energy dispersive x-ray fluorescence (EDXRF) for screening micronutrient concentrations in lentil and sorghum grain for biofortification breeding programs. Methods Lentil and sorghum seed was provided from biofortification breeding programs and analysed with inductively coupled plasma mass spectrometry (ICP-MS) to determine the reference concentration levels of Ca, Mn, Fe, Cu and Zn. A subset of these samples was used to establish the EDXRF calibration and another subset used for validation of the method. Results The results show the EDXRF analyses of the lentil and sorghum are not significantly different to the reference ICP-MS for all elements analysed, except for Mn with %RSD of replicate analysis < 5 % for lentil analysis and < 10 % for sorghum. Conclusions EDXRF analysis enables rapid and accurate analysis of Ca, Mn, Fe, Cu and Zn in lentil and sorghum.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Marek Dziadosz ◽  
Katarina Bolte ◽  
Wolfgang Rosenberger ◽  
Michael Klintschar ◽  
Jörg Teske

Abstract Objectives Since melperone abuse with lethal intoxication is common, expert opinions based on therapeutical and lethal concentration ranges can be considered as important. Because there is a lack of information about fatalities caused by melperone mono-intoxications and data on tissue samples with concentration distribution, the aim of this work is the examination of lethal concentration ranges of melperone and drug quantification in different matrices. Methods An LC-MS/MS method was applied for analyses performed in blood and tissue samples. Quantification based on standard addition and sample preparation on liquid–liquid extraction with 1-chlorobutane. An appropriate tissue homogenization was performed ahead of extraction with an IKA Ultra-Turrax-Tube-Drive®. A Luna 5 µm C18 (2) 100 Å, 150  × 2 mm analytical column was used for chromatographic separation and the elution was performed with two mobile phases consisted of A (H2O/methanol = 95/5, v/v) and B (H2O/methanol = 3/97, v/v) both with 10 mM ammonium acetate and 0.1% acetic acid. Results A multi-drug LC-MS/MS analytical method developed was applied successfully for melperone quantification in different post-mortem matrices. No analytical problems could be identified during method development and analyses of real samples. The melperone lethal concentration calculated in femoral blood of the drug mono-intoxication investigated was 10 mg/L. Melperone concentration distribution was presented for the first time. Conclusions The lethal reference concentration of melperone in femoral blood of 17.1 mg/L pointed out in different reference lists should be used with caution. Instead, a lower lethal melperone concentration should be considered. The post-mortem concentration distribution of the drug presented could be helpful in the interpretation of cases where no blood samples are available.


2021 ◽  
Vol 54 (2) ◽  
Author(s):  
Simon Fjendbo ◽  
Henrik E. Sørensen ◽  
Klaartje De Weerdt ◽  
Mette R. Geiker

AbstractA recent observation showed a square root time dependency of the ingress depth of a fixed (reference) chloride concentration of 0.05% chloride by mass of concrete for submerged exposure in Kattegat and the Baltic Sea. The purpose of this paper is to assess the applicability and limitations of the observation, widen the scope of validity and propose it as a method. Field data from submerged, tidal, splash, atmospheric and inland deicing salt exposure at various geographical locations was analyzed at a range of reference concentrations. In total 237 combinations of concrete, exposure, and reference concentration were analyzed. Our results showed that chloride ingress of a reference concentration followed a linear relationship with an average R2 of 0.96, when the penetration depth of the reference concentration was plotted against the square root of the exposure time. The square root observation appeared valid for the studied Portland cement based concretes with fly ash, silica fume and ground granulated blast furnace slag exposed in submerged and tidal exposure zones, when applying reference concentrations of 0.1–1.8% chloride by mass of binder, and reference concentrations of 0.1–0.5% chloride by mass of binder in atmospheric exposure zone. It was found that the parameters describing the straight line depended on the chosen reference concentration and concrete composition, and that the slope of the straight line (ingress parameter) in addition depended on the exposure. It was concluded that the square root method appears to be a promising method for predicting further chloride ingress into concrete.


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