Analysis of promissory situation pragmatic structure

The article is devoted to the analysis of two promissory situation pragmatic structures. The analysis helped us reveal the strategic potential of promising and conclude about the benefit of promised actions for participants of the interaction.Статья посвящена анализу двух прагматических структур ситуации обещания. Анализ позволил выявить стратегический потенциал обещания и сделать выводы о выгодности обещанного действия для участников коммуникации

Role of tyrosine M210 in the initial charge separation of reaction centers of Rhodobacter sphaeroides

Femtosecond spectroscopy was used in combination with site-directed mutagenesis to study the influence of tyrosine M210 (YM210) on the primary electron transfer in the reaction center of Rhodobacter sphaeroides. The exchange of YM210 to phenylalanine caused the time constant of primary electron transfer to increase from 3.5 f 0.4 ps to 16 f 6 ps while the exchange to leucine increased the time constant even more to 22 f 8 ps. The results suggest that tyrosine M210 is important for the fast rate of the primary electron transfer

Modified reaction centers from Rhodobacter sphaeroides R26

Incubation of photosynthetic reaction centers from Rhodobacter sphaeroides R26 with exogenous 132-OH-bacteriochlorophyll ap or aGG according to Scheer et al. (1987) results in the exchange of endogenous bacteriochlorophyll ap. The exchange amounts to less-than-or-equals, slant 50% according to HPLC analysis, corresponding to a complete replacement of the ‘monomeric’ bacteriochlorophylls, bm and bl, by exogenous pigment. The absorption spectra show small, but distinct changes in the Qx-region of the bacteriochlorophylls, and bleaching of the modified reaction centers is retained. The corresponding binding sites must be accessible from the exterior, and allow for the introduction of a polar residue at C-132. This is supported by the observation of side reactions of the endogenous ‘monomeric’ bacteriochlorophylls within the reaction center pigments, e.g. epimerization and hydroxylation at C-132

Quality of treatment and surgical approach for rectal gastrointestinal stromal tumour (GIST) in a large European cohort

Background: Rectal gastrointestinal stromal tumours (GISTs) are rare tumours. Variability in the managementmay influence outcome, but there is a lack of understanding regarding contemporary variancein care. A multicenter, international, retrospective cohort study was performed to elucidate characteristicsand outcomes of rectal GIST in European practice, with particular reference to surgical approach.Methods: All rectal GIST patients diagnosed between 2009 and 2018 were identified from five Europeandatabases. Recurrence free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meiermethod. Possible confounders were identified using Cox regression analyses.Results: From 210 patients, 155 patients had surgery. The three main types of surgery were local tumourresection (LTR, n ¼ 46), low anterior resection (LAR, n ¼ 31) and abdomino-perineal resection (APR,n ¼ 32). Most patients received neoadjuvant (65%) and/or adjuvant imatinib therapy (66%). Localrecurrence rate after surgery was 15% and overall recurrence rate 28%. No significant differences werefound in terms of RFS nor OS between LTR, LAR and APR. However, locally resected tumours weresmaller, while LAR and APR patients more often received perioperative imatinib. General hospitalstreated smaller GISTs, offered imatinib less frequently, and had a higher tumour rupture rate. In the multivariate analysis in the group having LTR, APR or LAR, the only significant prognostic factor for localrecurrence was higher age (HR 1.06, CI 1.00e1.12, p ¼ 0.048).Conclusions: In European clinical practice for rectal GIST, LTR, LAR and APR have comparable localcontrol. Multimodal approach is higher and tumour rupture less frequent in specialist centres comparedto general hospitals.Experimentele farmacotherapi

Weak temperature dependence of P (+) H A (-) recombination in mutant Rhodobacter sphaeroides reaction centers

International audienceIn contrast with findings on the wild-type Rhodobacter sphaeroides reaction center, biexponential P (+) H A (-) → PH A charge recombination is shown to be weakly dependent on temperature between 78 and 298 K in three variants with single amino acids exchanged in the vicinity of primary electron acceptors. These mutated reaction centers have diverse overall kinetics of charge recombination, spanning an average lifetime from ~2 to ~20 ns. Despite these differences a protein relaxation model applied previously to wild-type reaction centers was successfully used to relate the observed kinetics to the temporal evolution of the free energy level of the state P (+) H A (-) relative to P (+) B A (-) . We conclude that the observed variety in the kinetics of charge recombination, together with their weak temperature dependence, is caused by a combination of factors that are each affected to a different extent by the point mutations in a particular mutant complex. These are as follows: (1) the initial free energy gap between the states P (+) B A (-) and P (+) H A (-) , (2) the intrinsic rate of P (+) B A (-) → PB A charge recombination, and (3) the rate of protein relaxation in response to the appearance of the charge separated states. In the case of a mutant which displays rapid P (+) H A (-) recombination (ELL), most of this recombination occurs in an unrelaxed protein in which P (+) B A (-) and P (+) H A (-) are almost isoenergetic. In contrast, in a mutant in which P (+) H A (-) recombination is relatively slow (GML), most of the recombination occurs in a relaxed protein in which P (+) H A (-) is much lower in energy than P (+) H A (-) . The weak temperature dependence in the ELL reaction center and a YLH mutant was modeled in two ways: (1) by assuming that the initial P (+) B A (-) and P (+) H A (-) states in an unrelaxed protein are isoenergetic, whereas the final free energy gap between these states following the protein relaxation is large (~250 meV or more), independent of temperature and (2) by assuming that the initial and final free energy gaps between P (+) B A (-) and P (+) H A (-) are moderate and temperature dependent. In the case of the GML mutant, it was concluded that the free energy gap between P (+) B A (-) and P (+) H A (-) is large at all times

Analysis of promissory situation pragmatic structure

The article is devoted to the analysis of two promissory situation pragmatic structures. The analysis helped us reveal the strategic potential of promising and conclude about the benefit of promised actions for participants of the interaction.Статья посвящена анализу двух прагматических структур ситуации обещания. Анализ позволил выявить стратегический потенциал обещания и сделать выводы о выгодности обещанного действия для участников коммуникации

Olivines from ultramafic rocks of Jordanów-Gogołów Serpentinite Massif (Sudetic ophiolite) - a complex interplay of petrogenetic processes

Olivines occurring in the Jordanów-Gogołów Serpentinite Massif (JGSM) in the Polish Sudetes were formed during complex series of geological events and processes: growth in the upper mantle; crystallization of ultramafic cumulates at a mid-ocean ridge; ultra-high pressure (UHP) and high pressure metamorphism in a subduction zone; and contact metamorphism related to intrusion of boninitic and/or granitic magmas into the JGSM. The presence of olivine with pseudocleavage and intergrowths of ferrichromite and of pseudospinifex olivine indicates very fast transport from UHP conditions (from depths ca. 410 km) to the surface, similar to the model proposed by Brueckner & van Roermund (2004). The range of metamorphic conditions (from UHP to zeolite facies) recorded by JGSM olivines and also by associated serpentinites indicates that the JGSM is a fragment of an accretionary prism

Study of wild type and genetically modified reaction centers from Rhodobacter capsulatus: structural comparison with Rhodopseudomonas viridis and Rhodobacter sphaeroides.

Reaction centers from the purple bacterium Rhodobacter (Rb.) capsulatus and from two mutants ThrL226-->Ala and IleL229-->Ser, modified in the binding protein pocket of the secondary quinone acceptor (QB), have been studied by flash-induced absorbance spectroscopy. In ThrL226-->Ala, the binding affinities for endogenous QB (ubiquinone 10) and UQ6 are found to be two to three times as high as the wild type. In contrast, in IleL229-->Ser, the binding affinity for UQ6 is decreased about three times compared to the wild type. In ThrL226-->Ala, a markedly increased sensitivity (approximately 30 times) to o-phenanthroline is observed. In Rhodopseudomonas viridis, where Ala is naturally in position L226, the sensitivity to o-phenanthroline is close to that observed in ThrL226-->Ala. We propose that the presence of Ala in position L226 is responsible for the high sensitivity to that inhibitor. The pH dependencies of the rate constants of P+QB- (kBP) charge recombination kinetics (P is a dimer of bacteriochlorophyll, and QB is the secondary quinone electron acceptor) show destabilization of QB- in ThrL226-->Ala and IleL229-->Ser, compared to the wild type. At low pH, similar apparent pK values of protonation of amino acids around QB- are measured in the wild type and the mutants. In contrast to Rb. sphaeroides, in the wild type Rb. capsulatus, kBP substantially increases in the pH range 7-10. This may reflect some differences in the respective structures of both strains or, alternatively, may be due to deprotonation of TyrL 215 in Rb. capsulatus. At pH 7, measurements of the rate constant of QA to QB electron transfer reveal a threefold greater rate in the reaction centers from wild type Rb. capsulatus (65 +/- 1 0 ps)-1 compared to Rb. sphaeroides.We suggest that this may arise from a 0.7-A smaller distance between the quinones in the former strain. Our spectroscopic data on the wild type Rb. capsulatus reaction center suggest the existence of notable differences with the Rb. sphaeroides reaction center structure