247 research outputs found
The impact of ultrafiltration on the molecular properties of bovine lactoferrin: molecular mass, primary structure and glycosylation variations
No full textMass spectra of intact bovine lactoferrin before and after ultrafiltration obtained by matrix-assisted laser desorption/ionization time-of-flight mass (MALDI-TOF-MS) spectrometer Bruker ultrafleXtreme (Bruker Daltonik, Bremen, Germany) were recorded in the positive ion linear mode in m/z range of 25000-250000 using accelerating voltage of 25 kV. Saturated solution of sinapinic acid (SA) dissolved in TA30 (mixture of 0.1 % TFA and ACN at the 70:30 (v/v) was used as matrix solution, while Protein Calibration Standard II (Bruker Daltonics, Bremen) was selected for calibration.Peptide mass fingerprint (PMF) of bovine lactoferrin before and after ultrafiltration in both, reduced and non-reduced conditions, was recorded in MS mode in the reflectron positive ion mode within m/z range of 500-3500. Saturated α-cyano-4-hydroxycinnamic acid (HCCA) in TA30 was used as a matrix solution, while the Peptide Calibration Standard II (Bruker Daltonics, Bremen) was applied as a calibrant.MS/MS fragments of bovine lactoferrin were obtained in Laser Ionization Fragmentation Technologies (LIFT) mode. The common criteria selected for the bLF identification was the peak intensity ˃ 1000 a.u., except for bovine lactoferrin before ultrafiltration at non-reduced conditions in which case the criteria was changed to intensity ˃ 3000 a.u. Cysteine carbamidomethylation and methionine oxidation were selected as global and variable modifications, respectively. Variable modification, such as HexNAc (N), Hex(1)HexNAc(2) (N), HexNAc(2)dHex(1) (N), HexNAc(2)dHex(1) (N), Hex(1)HexNAc(1)dHex(1) (N), and Hex(1)HexNAc(1)NeuAc(1) (N) were applied in order to indicate matches (glycopeptides), representing the potential glycosylation sites. Mascot database along with BioTools were applied for the result interpretation.</p
Hydrogen Bond-Mediated Conjugates Involving Lanthanide Diphthalocyanines and Trifluoroacetic Acid (Lnpc2@TFA): Structure, Photoactivity, and Stability
No full textThe interaction between lanthanide diphthalocyanine complexes, LnPc2 (Ln = Nd, Sm, Eu, Gd, Yb, Lu; Pc = C32H16N8, phthalocyanine ligand) and trifluoroacetic acid (TFA) was investigated in benzene, and the stability of the resulting molecular system was assessed based on spectral (UV-Vis) and kinetic measurements. Structural Density Functional Theory (DFT) calculations provided interesting data regarding the nature of the bonding and allowed estimating the interaction energy between the LnPc2 and TFA species. Conjugates are created between the LnPc2 and TFA molecules via hydrogen bonds of moderate strength (>N∙∙H··) at the meso- -bridges of the Pc moieties, which renders the sandwich system to flatten. Attachment of TFA is followed by rearrangement of electronic density within the chromophore system of the macrocycles manifested in considerable changes in their UV-Vis spectra and consequently the color of the studied solutions (from green to orange). The LnPc2@TFA conjugates including Nd, Sm, Eu, and Gd appeared evidently less photostable when exposed to UV radiation than the related mother compounds, whereas in the case of Yb and Lu derivatives some TFA-prompted stabilizing effect was noticed. The conjugates displayed the capacity for singlet oxygen generation in contrast to the LnPc2s itself. Photon upconversion through sensitized triplet-triplet annihilation was demonstrated by the TFA conjugates of Nd, Sm, Eu, and Gd
Novel Lipophilic Lanthanide Bis-Phthalocyanines Functionalized by Pentadecylphenoxy Groups: Synthesis, Characterization and UV-Photostability
No full textNovel sandwich-type phthalocyanines containing a rare earth metal core (Pr, Nd, Eu–Lu) and macrocycles peripherally substituted by pentadecylphenoxy groups were synthesized using a cardanol-based phthalonitrile precursor and the respective lanthanide acetate. Additionally, the metal free-base analog compound was studied for comparison. The purified reaction products were all found to be thick and viscous substances at room temperature, showing liquid crystalline behavior with a distinct increase in fluidity at ca. 40 °C. The complexes are readily soluble in chloroalkyl solvents and dissolve fairly well in DMF with some tendency to form aggregates. Besides they are strongly hydrophobic and reveal a peculiar affinity for lipophilic media. The compounds have been characterized by UV-Vis (absorption and emission), FTIR, MS and DSC methods. Photochemical activity in the liquid phase (dimethylformamide, dichloromethane, mineral oil) and the degree of photodegradation demonstrated under constant UV-irradiation (λ = 352 nm) have been analyzed and discussed in terms of photostability
STRUCTURAL AND MOLECULAR CHARACTERIZATION OF MESO-SUBSTITUTED ZINC PORPHYRINS: A DFT SUPPORTED STUDY
No full textStructural parameters of a range of over 100 meso-substituted zinc porphyrins were reviewed and compared to show how far the nature of the functional group may affect the interatomic distances and bond angles within the porphyrin core. It was proved that even despite evident deformations of the molecular structure, involving twisting of the porphyrin's central plane, the coupled π-bonding system remains flexible and stable. DFT
calculations were applied to a number of selected porphyrins representative for the reviewed compounds to emphasize the relevance of theoretical methods in structural investigations of complex macrocyclic molecular systems. Experimental and DFT-simulated IR spectral data were reported and analyzed in context of the individual molecular features introduced by the meso substituents into the porphyrin moiety base. Raw experimental
spectral data, including 1H- and 13C-NMR, UV-Vis, FTIR, XRD, and other relevant physicochemical details have been provided for a specially chosen reference zinc porphyrin functionalized by tert-butylphenyl groups
Comparison of Four Lens Power Formulas for Sutureless Scleral-Fixated Carlevale Lens
No full textAgnieszka Dyrda,1,2 Liliana Araujo-Diaz,1 Amanda Rey,1 Maria S Pighin,1 Marta Pazos,3 Ignasi Jürgens1 1Institut Català de Retina, Barcelona, Spain; 2Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona (UB), Barcelona, Spain; 3Department of Ophthalmology, Hospital Clínic de Barcelona, Universitat de Barcelona (UB), Barcelona, Spain; Institut d’Investigacions Mèdiques August Pi i Sunyer (IDIBAPS), Barcelona, SpainCorrespondence: Agnieszka Dyrda, Institut Català de Retina, Ganduxer 117, Barcelona, 08022, Spain, Tel +34 93 378 23 19, Fax +34 93 418 78 57, Email [email protected]: To assess the predictability of intraocular lens (IOL) power calculation formulas for sutureless scleral fixation (SSF) of the Carlevale IOL.Methods: A prospective, single-center, interventional case series was conducted to compare predicted refractive outcomes using the SRK/T, Barrett II, Hoffer Q, and Holladay 1 formulas in patients undergoing SSF of the Carlevale IOL. The main outcomes included mean prediction error (PE), median absolute error (MedAE), mean absolute error (MAE), and the percentage of eyes with a PE within ± 0.50 and ± 1.0 diopters (D).Results: Sixty-nine eyes of 69 patients were included. Only the Barrett II formula resulted in a systematic myopic error (p=0.014). The PE of SRKT, HofferQ, and Holladay 1 was closer to 0, indicating that the post-operative refractive outcome was nearer to the predicted value than that of Barrett II (p=0.002, p< 0.001, p=0.003, respectively). MedAE and MAE ranged from 0.41 to 0.53 D and 0.6 to 0.67 D, respectively, without significant differences between the formulas. The percentages of eyes with PE within ± 0.50 and ± 1.00 D varied from 47.8 to 56.5% and 79.7 to 87%, respectively, showing no significant differences across the assessed formulas.Conclusion: The SRK/T, Hoffer Q, and Holladay 1 formulas provide favorable refractive outcomes for the SSF of Carlevale IOL. The Barrett II formula is less accurate and is not recommended due to its systematic myopic refractive error.Keywords: Carlevale IOL, sutureless scleral fixation, IOL power formula, refractive results, refractive prediction erro
Kompetencje nauczyciela w pracy z uczniami zdolnymi : wybrane wyniki badań empirycznych nad edukacyjnym wspieraniem rozwoju uczniów zdolnych
No full textThe author presents chosen results of research concerning institutional and
individual support for gifted students’ development in Polish schools. In this article the
focus was put on the competences of teachers working and teaching gifted and talented
students
Momosa pragmatyzm prawny: rzeczywiste granice teorii, rozsądne granice krytyki
No full textNiniejszy tekst składa się z dwóch zasadniczych części. W pierwszej autor dokonuje krótkiej charakterystyki pragmatyzmu prawnego jako kierunku teoretycznoprawnego. W drugiej wskazuje krótko na podstawowe zarzuty, jakie są wysuwane pod adresem pragmatyzmu prawnego, aby wykazać, że przynajmniej niektóre z nich są oparte na nieporozumieniu. Przy tym ostatnim zadaniu posłuży się taktyką, której zasadniczą zaletą jest to, że pozwala ona ujawnić cechy swoiste danej teorii na zasadzie kontrastu, tj. przez pryzmat zniekształceń dokonywanych przez nieprzychylnych krytyków. Autor zwraca również uwagę na fakt, iż coraz częściej pozytywizm prawny oraz pragmatyzm prawniczy nawet jeśli nie mają ze sobą wiele wspólnego, to przynajmniej nie pozostają w konflikcie, jeśli interpretować je życzliwie.Udostępnienie publikacji Wydawnictwa Uniwersytetu Łódzkiego finansowane w ramach projektu „Doskonałość naukowa kluczem do doskonałości kształcenia”. Projekt realizowany jest ze środków Europejskiego Funduszu Społecznego w ramach Programu Operacyjnego Wiedza Edukacja Rozwój; nr umowy: POWER.03.05.00-00-Z092/17-00
Kompetencje nauczyciela w pracy z uczniami zdolnymi — wybrane wyniki badań empirycznych nad edukacyjnym wspieraniem rozwoju uczniów zdolnych
No full textThe author presents chosen results of research concerning institutional and individual support for gifted students’ development in Polish schools. In this article the focus was put on the competences of teachers working and teaching gifted and talented students.Autor przedstawia wybrane wyniki badań dotyczących instytucjonalnego i indywidualnego wspierania rozwoju uczniów zdolnych w polskich szkołach. W artykule skoncentrowano się na kompetencjach nauczycieli pracujących z uczniami zdolnymi i utalentowanymi
The situation of gifted students in the Polish educational system
No full textThe author presents results of triangulated qualitative and quantitative research concerning institutional and individual support for gifted students’ development in Polish schools. The research study was conducted in three stages: case studies of schools, a survey of teachers’ perceptions and educational biographies transcribed from interviews of gifted and talented students. Conclusions are presented in the form of a model of educational support of gifted students’ development and recommendations concerning the planning and implementation of this support are proposed
The Situation of Gifted Students in the Polish Education System
No full textThe author presents results of triangulated qualitative and quantitative research concerning institutional and individual support for gifted students’ development in Polish schools. The research study was conducted in three stages: case studies of schools, a survey of teachers’ perceptions and educational biographies transcribed from interviews of gifted and talented students. Conclusions are presented in the form of a model of educational support of gifted students’ development and recommendations concerning the planning and implementation of this support are proposed
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