526 research outputs found
Resolution of 1-n-Butyl-3-Methyl-3-Phospholene 1-Oxide with TADDOL Derivatives and Calcium Salts of O,O’-Dibenzoyl-(2R,3R)- or O,O’-di-p-Toluoyl-(2R,3R)-tartaric Acid
The resolution methods applying (−)-(4R,5R)-4,5-bis(diphenylhydroxymethyl)-2,2-dimethyldioxolane (“TADDOL”), (−)-(2R,3R)-α,α,α',α'-tetraphenyl-1,4-dioxaspiro[4.5]decan-2,3-dimethanol (“spiro-TADDOL”), as well as the acidic and neutral Ca2+ salts of (−)-O,O’-dibenzoyl- and (−)-O,O’-di-p-toluoyl-(2R,3R)-tartaric acid were extended for the preparation of 1-n-butyl-3-methyl-3-phospholene 1-oxide in optically active form. In one case, the intermediate diastereomeric complex could be identified by single crystal X-ray analysis. The absolute P-configuration of the enantiomers of the phospholene oxide was also determined by comparing the experimentally obtained and calculated CD spectra
(S P,S P)-(–)-(E)-1,2-Bis(methylphenylphosphinoyl)ethene
The title compound, C16H18O2P2, possesses two stereogenic P atoms and shows a distorted s–cis conformation of each O=P—C=C moiety. This has been suggested on the basis of the stereochemical result of 1,3-dipolar cycloadditions with nitrones and is now confirmed by the present crystal structure analysis. There are two crystallographically independent molecules in the asymmetric unit
Influence of 1% addition of Nb and W on the relaxation process in classical Fe-based amorphous alloys
This paper features investigations into the influence of small additions of alloying elements on: structure, as well as the temporal and thermal stability of magnetic properties, and the disaccommodation effect, for the following amorphous alloys: Fe₆₁Co₁₀Y₈Me₁B₂₀ (where Me = Nb, W). The structure of the investigated samples has been confirmed by the Mössbauer spectroscopy. The obtained results indicate a strong correlation between the structure and the disaccommodation of the studied alloys. The Mössbauer studies reveal different configurations of atoms in the amorphous alloy samples, and the results indicate various potential barriers between orientations of atom pairs. For this reason, to describe the disaccommodation effect, the distribution of activation energy should be taken into account. The distribution of activation energy has been related to the distribution of relaxation times
Regenerative potential and its variability in different topophysical zones of Kalanchoe daigremontiana leaves in in vitro culture conditions
Plants of the genus Kalanchoe are the most frequently purchased potted plants because of their decorative qualities and easy cultivation. Modern commercial plants have unique shapes that are usually not genetically determined; hence, in vitro cultures are used to propagate such specimens. The efficiency of regeneration is significantly affected by the type of explant used when that explant was previously located on one of several parts of a complex plant organ. The study aimed to investigate the influence of the topophysical location of collected explants on the regeneration efficiency of adventitious shoots. Various regeneration pathways were observed in the in vitro micropropagation of Kalanchoe daigremontiana leaf fragments, i.e., direct and indirect organogenesis from the callus stage. The results show a dependent relationship between the location of the collected explant and its regenerative potential. The most remarkable regenerative capacity of K. daigremontiana was found in leaf blade fragments taken from the middle and proximal zones. In addition, the explants collected from the marginal zone of the leaf blade were notably more valuable than those from the part located near the midrib. The research results indicate that the growth and development of new seedlings propagated vegetatively with the in vitro method depends on their location on the mother plant.Plants of the genus Kalanchoe are the most frequently purchased potted plants because of their decorative qualities and easy cultivation. Modern commercial plants have unique shapes that are usually not genetically determined; hence, in vitro cultures are used to propagate such specimens. The efficiency of regeneration is significantly affected by the type of explant used when that explant was previously located on one of several parts of a complex plant organ. The study aimed to investigate the influence of the topophysical location of collected explants on the regeneration efficiency of adventitious shoots. Various regeneration pathways were observed in the in vitro micropropagation of Kalanchoe daigremontiana leaf fragments, i.e., direct and indirect organogenesis from the callus stage. The results show a dependent relationship between the location of the collected explant and its regenerative potential. The most remarkable regenerative capacity of K. daigremontiana was found in leaf blade fragments taken from the middle and proximal zones. In addition, the explants collected from the marginal zone of the leaf blade were notably more valuable than those from the part located near the midrib. The research results indicate that the growth and development of new seedlings propagated vegetatively with the in vitro method depends on their location on the mother plant.
Klauzula przeciwko unikaniu opodatkowania: norma, do której stosowania zobowiązany jest podatnik, czy regulacja stosowana wyłącznie przez organ podatkowy?
The article discusses whether the Polish general anti-avoidance rule (GAAR), especially in the light of the amendments binding as of 1 January 2019, is supposed to be applied by a taxpayer during the calculation of due tax, or whether only the tax authorities are authorized to apply the GAAR during tax proceedings. The authors claim that the GAAR is applicable ex lege. They criticize the justification for amendments to the tax ordinance introduced as of 1 January 2019, which states otherwise, pointing out that the interpretation adopted in this justification leads to contradictions in the law.
Przedmiotem artykułu pozostaje analiza, czy do stosowania przepisów klauzuli przeciwko unikaniu opodatkowania, w szczególności w świetle zmian obowiązujących od 1 stycznia 2019 r., jest zobowiązany sam podatnik w toku samoobliczenia podatku, czy też może ją zastosować jedynie organ podatkowy w toku postępowania podatkowego. Autorzy w tekście dowodzą, iż norma ogólna przeciwko unikaniu opodatkowania znajduje zastosowanie ex lege i że do jej stosowania jest zobowiązany sam podatnik w toku ustalania wymiaru obciążającego podatku. Krytykują oni tezę przeciwną zawartą w uzasadnieniu projektu ustawy wprowadzającej od 1 stycznia 2019 r. zmiany do Ordynacji podatkowej, wskazując, iż przyjęta w nim interpretacja przeciwna prowadzi do sprzeczności przepisów prawa
The Influence of Structural Relaxation on the Holstein-Primakoff Paraprocess
Structural relaxations play a large role in forming the properties of magnetic materials. In amorphous alloys, which are metastable materials, obtaining a relatively stable structure requires a properly designed thermal treatment process. Samples should be annealed above the Curie temperature and below the crystallization temperature. With the process designed in such a way, the domain structure is not interfered with and the formation of crystal grains does not occur. By analyzing the so-called Holstein–Primakoff paraprocess, it is possible to determine the influence of magnetic atoms on the magnetization process in strong magnetic fields above the field of effective anisotrop
Rational design of novel ligands for environmentally benign cross-coupling reactions
Transition-metal (TM) complexes of new phosphines, readily prepared by a straight forward three-step modular synthesis, were successfully employed in difficult crosscoupling reactions conducted under mild conditions (water, “open-flask”, low temperature) that aspire to meet green chemistry criteria. High yielding catalyzed by bismuth or rhodium complexes oxidative arylation of naphthoquinone gave the key 2-arylnaphthoquinone intermediates for facile bismuth triflate-catalyzed Michael addition of secondary phosphine oxides. Subsequent O-methylation and reductions of the resulting products gave access to the target air-stable phosphine ligands in good overall yields (up to 60 %)
Nanostructured carbon materials decorated with organophosphorus moieties: Synthesis and application
A new synthetic approach for the production of carbon nanomaterials (CNM) decorated with organophosphorus moieties is presented. Three different triphenylphosphine oxide (TPPO) derivatives were used to decorate oxidized multiwalled carbon nanotubes (ox-MWCNTs) and graphene platelets (GPs). The TPPOs chosen bear functional groups able to react with the CNMs by Tour reaction (an amino group), nitrene cycloaddition (an azido group) or CuAAC reaction (one terminal C–C triple bond). All the adducts were characterized by FTIR, Raman spectroscopy, TEM, XPS, elemental analysis and ICP-AES. The cycloaddition of nitrene provided the higher loading on ox-MWCNTs and GPs as well, while the Tour approach gave best results with nanotubes (CNTs). Finally, we investigated the possibility to reduce the TPPO functionalized CNMs to the corresponding phosphine derivatives and applied one of the materials produced as heterogeneous organocatalyst in a Staudinger ligation reaction
Is there respectful maternity care in Poland? Women’s views about care during labor and birth.
Background: Abuse against women in labor starts with subtle forms of discrimination that can turn into overt violence. Therefore it is crucial to work towards prevention and elimination of disrespect and ill-treatment in medical facility perinatal care in which staff allows such abuse. The aim of the study was to analyze the experiences of women related to perinatal care. Special emphasis was put on experiences that had traits indicating disrespectful and offensive care during childbirth in medical facilities providing perinatal care. Methods: This was a cross-sectional survey. A questionnaire was prepared for respondents who gave birth in medical facilities. Information about the study was posted on the website of a non-governmental foundation dealing with projects aimed at improving perinatal care. The respondents gave online consent for processing the submitted data. 8378 questionnaires were submitted. The study was carried out between February 06 and March 20, 2018. The results were analyzed using the Chi-square independence test. The analysis was carried out at the significance level of 0.05 in Excel, R and SPSS. Results: During their hospital stay, 81% of women in the study experienced violence or abuse from medical staff on at least one occasion. The most common abuse was having medical procedures without prior consent. Inappropriate comments made by staff related to their own or a woman’s situation were reported in 25% of situations, whilst 20% of women experienced nonchalant treatment. In the study 19.3% of women reported that the staff did not properly care for their intimacy and 1.7% of the respondents said that the worst treatment was related to feeling anonymous in the hospital. Conclusions: The study shows that during Polish perinatal care women experience disrespectful and abusive care. Most abuse and disrespect involved violation of the right to privacy, the right to information, the right to equal treatment, and the right to freedom from violence. The low awareness of abuses and complaints reported in the study may result from women’s ignorance about relevant laws related to human rights
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