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51.
52.
Józef Drabowicz Piotr Łyżwa Jan Omelańczuk Marian Mikołajczyk 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract The title compound optically active t-butylphenylphosphine oxide 1 is widely used as a key substrat for the synthesis of other optically active derivatives such as α-hydroxyphosphine oxides, vinylphosphine oxides Till now, it has been obtained by a few rather laborious procedures1 相似文献
53.
Dumitru Tita Tunde Jurca Adriana Fulias Eleonora Marian Bogdan Tita 《Journal of Thermal Analysis and Calorimetry》2013,112(1):407-419
This study is part of a research project aimed to find and optimize methods by which drug-excipient compatibility can be reliably and quickly assessed. The objective of the present study was to evaluate the compatibility of the acetylsalicylic acid (ASA), an non-steroidal anti-inflammatory drug, with pharmaceutical excipients of common use including diluents, binders, disintegrants, lubricants and solubilising agents. In order to investigate the possible interactions between ASA and eleven excipients differential scanning calorimetry (DSC) and thermogravimetry/derivative thermogravimetry analysis completed by Fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction were used for compatibility study. The DSC has proven to be, among the selected analytical techniques, the most sensitive and specific in assessing the compatibility. The samples, as physical mixtures, were prepared by mixing the analyte and excipients in a proportion of 1:1 (w:w). On the basis of thermal results (especially DSC), confirmed by FT-IR and X-ray analysis, a possible chemical interaction was found between the ASA with polyvinylpyrrolidone K30 (PVP) and magnesium stearate, respectively a possible physical interaction with colloidal silicon dioxide and stearic acid (Ac. St.). 相似文献
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55.
The thermal decomposition of 3-(α-trimethylsilyl)alkyl substituted 2-(phenylsulfinyl)cycloalkanones occurs via the γ-sila-Pummerer reaction, affording 3-substituted cycloalk-2-enones and unstable trimethylsilyl benzenesulfenate as an elimination by-product. The starting γ-silyl substituted cycloalkanoyl sulfoxides were obtained through the conjugate addition reaction of nucleophilic reagents to 2-(phenylsulfinyl)cycloalk-2-enones. The tandem conjugate addition/γ-sila-Pummerer reaction investigated here provides a new route to 3-substituted cycloalk-2-enones. 相似文献
56.
Ileana Radulescu Marian Romeo Calin 《Journal of Radioanalytical and Nuclear Chemistry》2014,301(1):141-146
Proficiency testing is among the most methods to assess the accuracy of the analytical data produced by laboratories. The results presented in this paper show the performance of the laboratory for three intercomparisons organized by Radionuclide Metrology Laboratory (RML) and by IAEA, in which SALMROM laboratory have participated in three consecutive years. The feedbacks from the final reports from RML and IAEA demonstrate the performance of the laboratory where 34 out of 39 pass all acceptance criteria of the test. The rest of five results which failed served to improve the laboratory analysis and to optimize accuracy measurements. The overall results of the proficiency tests point out the reliability and traceability of the gamma spectrometry system used for environmental measurements. 相似文献
57.
Mahrous Awad M. A. El-Desoky A. Ghallab Jan Kubes S. E. Abdel-Mawly Subhan Danish Disna Ratnasekera Mohammad Sohidul Islam Milan Skalicky Marian Brestic Alaa Baazeem Saqer S. Alotaibi Talha Javed Rubab Shabbir Shah Fahad Muhammad Habib ur Rahman Ayman EL Sabagh 《Molecules (Basel, Switzerland)》2021,26(11)
Accumulation of heavy metals (HMs) by ornamental plants (OPs) from contaminated agriculture soils is a unique technique that can efficiently reduce the metal load in the food chain. Amaranthus tricolor L. has attractive characteristics acquiring a higher growth rate and large biomass when grown at heavy metal contaminated soils. Site-specific detailed information is not available on the use of A. tricolor plant in metal phytoremediation from the polluted sites. The study aimed to enhance the uptake of HMs (Pb, Zn, and Cu) via amending poultry litter extract (PLE), vinasse sugarcane (VSC), and humic acid (HA) as natural mobilized organic materials compared to ethylene diamine tetraacetic acid (EDTA), as a common mobilized chemical agent by A. tricolor plant. The studied soils collected from Helwan, El-Gabal El-Asfar (Cairo Governorate), Arab El-Madabeg (Assiut Governorate), Egypt, and study have been conducted under pot condition. Our results revealed all organic materials in all studied soils, except EDTA in EL-Gabal El-Asfar soil, significantly increased the dry weight of the A. tricolor plant compared to the control treatment. The uptake of Pb and Zn significantly (p > 0.05) increased due to applying all organic materials to the studied soils. HA application caused the highest uptake as shown in Pb concentration by more than 5 times in Helwan soil and EDTA by 65% in El-Gabal El-Asfar soil while VSC increased it by 110% in El-Madabeg soil. Also, an increase in Zn concentration due to EDTA application was 58, 42, and 56% for Helwan, El-Gabal El-Asfar, and El-Madabeg soil, respectively. In all studied soils, the application of organic materials increased the remediation factor (RF) than the control. El-Madabeg soil treated with vinasse sugarcane gave the highest RF values; 6.40, 3.26, and 4.02% for Pb, Zn, and Cu, respectively, than the control. Thus, we identified A. tricolor as a successful ornamental candidate that, along with organic mobilization amendments, most efficiently develop soil health, reduce metal toxicity, and recommend remediation of heavy metal-contaminated soils. Additionally, long-term application of organic mobilization amendments and continued growth of A. tricolor under field conditions could be recommended for future directions to confirm the results. 相似文献
58.
Marian Mikoajczyk Barbara Ziemnicka Jan Krzywaski Marek Cypryk Bartomiej Gostyski 《Molecules (Basel, Switzerland)》2021,26(12)
Geometrical cis- and trans- isomers of 2-chloro-, 2-bromo- and 2-fluoro-4-methyl-1,3,2-dioxaphosphorinan-2-thiones were obtained in a diastereoselective way by (a) sulfurization of corresponding cyclic PIII-halogenides, (b) reaction of cyclic phosphorothioic acids with phosphorus pentachloride and (c) halogen–halogen exchange at PIV-halogenide. Their conformation and configuration at the C4-ring carbon and phosphorus stereocentres were studied by NMR (1H, 31P) methods, X-ray analysis and density functional (DFT) calculations. The stereochemistry of displacement reactions (alkaline hydrolysis, methanolysis, aminolysis) at phosphorus and its mechanism were shown to depend on the nature of halogen. Cyclic cis- and trans-isomers of chlorides and bromides react with nucleophiles (HO−, CH3O−, Me2NH) with inversion of configuration at phosphorus. DFT calculations provided evidence that alkaline hydrolysis of cyclic thiophosphoryl chlorides proceeds according to the SN2-P mechanism with a single transition state according to the potential energy surface (PES) observed. The alkaline hydrolysis reaction of cis- and trans-fluorides afforded the same mixture of the corresponding cyclic thiophosphoric acids with the thermodynamically more stable major product. Similar DFT calculations revealed that substitution at phosphorus in fluorides proceeds stepwise according to the A–E mechanism with formation of a pentacoordinate intermediate since a PES with two transition states was observed. 相似文献
59.
Zahoor Ahmad Shazia Anjum Milan Skalicky Ejaz Ahmad Waraich Rana Muhammad Sabir Tariq Muhammad Ashar Ayub Akbar Hossain Mohamed M. Hassan Marian Brestic Mohammad Sohidul Islam Muhammad Habib-Ur-Rahman Allah Wasaya Muhammad Aamir Iqbal Ayman EL Sabagh 《Molecules (Basel, Switzerland)》2021,26(6)
Drought poses a serious threat to oilseed crops by lowering yield and crop failures under prolonged spells. A multi-year field investigation was conducted to enhance the drought tolerance in four genotypes of Camelina and canola by selenium (Se) application. The principal aim of the research was to optimize the crop yield by eliciting the physio-biochemical attributes by alleviating the adverse effects of drought stress. Both crops were cultivated under control (normal irrigation) and drought stress (skipping irrigation at stages i.e., vegetative and reproductive) conditions. Four different treatments of Se viz., seed priming with Se (75 μM), foliar application of Se (7.06 μM), foliar application of Se + Seed priming with Se (7.06 μM and 75 μM, respectively) and control (without Se), were implemented at the vegetative and reproductive stages of both crops. Sodium selenite (Na2SeO3), an inorganic compound was used as Se sources for both seed priming and foliar application. Data regarding physiochemical, antioxidants, and yield components were recorded as response variables at crop maturity. Results indicated that WP, OP, TP, proline, TSS, TFAA, TPr, TS, total chlorophyll contents, osmoprotectant (GB, anthocyanin, TPC, and flavonoids), antioxidants (APX, SOD, POD, and CAT), and yield components (number of branches per plant, thousand seed weight, seed, and biological yields were significantly improved by foliar Se + priming Se in both crops under drought stress. Moreover, this treatment was also helpful in boosting yield attributes under irrigated (non-stress) conditions. Camelina genotypes responded better to Se application as seed priming and foliar spray than canola for both years. It has concluded that Se application (either foliar or priming) can potentially alleviate adverse effects of drought stress in camelina and canola by eliciting various physio-biochemicals attributes under drought stress. Furthermore, Se application was also helpful for crop health under irrigated condition. 相似文献
60.
Gustavo Pereira Saito Ana Carolina Lanfredi Matsumoto Renata Pires Assis Iguatemy Loureno Brunetti Marco Aurlio Cebim Marian Rosaly Davolos 《Molecules (Basel, Switzerland)》2021,26(8)
Excessive UV solar radiation exposure causes human health risks; therefore, the study of multifunctional filters is important to skin UV protective ability and also to other beneficial activities to the human organism, such as reduction of reactive oxygen species (ROS) responsible for cellular damages. Potential multifunctional filters were obtained by intercalating of ferulate anions into layered simple metal hydroxides (LSH) through anion exchange and precipitation at constant pH methods. Ultrasound treatment was used in order to investigate the structural changes in LSH-ferulate materials. Structural and spectroscopic analyses show the formation of layered materials composed by a mixture of LSH intercalated with ferulate anions, where carboxylate groups of ferulate species interact with LSH layers. UV-VIS absorption spectra and in vitro SPF measurements indicate that LSH-ferulate systems have UV shielding capacity, mainly UVB protection. The results of reactive species assays show the ability of layered compounds in capture DPPH•, ABTS•+, ROO•, and HOCl/OCl− reactive species. LSH-ferulate materials exhibit antioxidant activity and singular optical properties that enable their use as multifunctional filters. 相似文献