218 research outputs found
Plant elongator-protein complex of diverse activities regulates growth, development, and immune responses
Contrary to the conserved Elongator composition in yeast, animals, and plants, molecular functions and catalytic activities of the complex remain controversial. Elongator was identified as a component of elongating RNA polymerase II holoenzyme in yeast, animals, and plants. Furthermore, it was suggested that Elonagtor facilitates elongation of transcription via histone acetyl transferase activity. Accordingly, phenotypes ofArabidopsis elomutants, which show development, growth, or immune response defects, correlate with transcriptional downregulation and the decreased histone acetylation in the coding regions of crucial genes. Plant Elongator was also implicated in other processes: transcription and processing of miRNA, regulation of DNA replication by histone acetylation, and acetylation of alpha-tubulin. Moreover, tRNA modification, discovered first in yeast and confirmed in plants, was claimed as the main activity of Elongator, leading to specificity in translation that might also result indirectly in a deficiency in transcription. Heterologous overexpression of individualArabidopsisElongator subunits and their respective phenotypes suggest that single Elongator subunits might also have another function next to being a part of the complex. In this review, we shall present the experimental evidence of all molecular mechanisms and catalytic activities performed by Elongator in nucleus and cytoplasm of plant cells, which might explain how Elongator regulates growth, development, and immune responses
Disclosure of unfavorable information in clinical practice
Przekazywanie niepomyślnych informacji stanowi istotny aspekt pracy lekarza onkologa. Znajomość dedykowanych technik komunikacji przynosi korzyści dla lekarza i pacjenta. W pracy omówiono podstawowe etapy procesu przekazywania niepomyślnych informacji na podstawie protokołu SPIKES, z przedstawieniem praktycznych przykładów. Przekazywanie niepomyślnych informacji powinno stanowić podstawową umiejętność lekarza onkologa.Disclosure of unfavorable information is an important aspect of the oncologist work. Knowledge of dedicated communication techniques is beneficial for the physician and the patient. The main steps in the process of unfavorable information disclosure, based on the SPIKES protocol, with practical examples, were described. Communicating the unfavorable news should be a basic skill of professional oncologist
New sensors based on silver nanowire arrays
Owing to its strong oxidizing properties, hydrogen peroxide has a wide range of applications. It is a key component for many industrial applications, such as pharmaceutical and cosmetic production or sterilization. Moreover, is produced in the human body by immune system cells and is a product of glucose oxidation. Therefore, creating an effective and selective method of detection has been of great importance. A novel glucose sensor, based on silver nanowires deposited into nanoporous anodic aluminum oxide (AAO) templates has been proposed. AAO templates has been prepared via anodization of Al in three electrolytes: oxalic, sulphuric and phosphoric acids. Silver nanowires has been created by deposition of silver in AAO templates. Electrodes based on silver nanowires were then investigated for electrocatalytical properties. reduction on silver nanowires was tested using cyclic voltammetry (CV) and chronoamperometry (ChA). An influence of interfering substances like ascorbic acid was also examined
Comparison of maternal and fetal blood levels of caffeine and its metabolite. A pilot study
Objective: The aim of the study was to compare caffeine and paraxanthine concentrations in venous blood of pregnant women and in the umbilical cord blood of their newborns. Materials and Methods: Pregnant women who gave birth at the Clinic of Obstetrics, Gynecology and Oncology, 2nd Faculty of Medicine, Medical University of Warsaw were included in the study. Caffeine and paraxanthine concentrations were analyzed in 30 samples of venous blood serum drawn from the women before delivery and 30 samples of umbilical cord blood serum of their newborns. Caffeine intake in the last 24 hours before delivery was estimated using a questionnaire. Statistical analysis employed a linear logistic regression model, Wilcoxon rank sum test and a non-parametric Spearman’s rank correlation coefficient. Results: No difference was found between caffeine concentration in maternal venous blood and neonatal umbilical cord blood. However, paraxanthine level in venous blood was higher than in umbilical cord blood (p = 0.04). Conclusions: Caffeine consumed by a pregnant woman passes through the placenta to the fetus freely
Hierarchical nanoporous systems obtained by anodic oxidation of electrochemically deposited Sn Nanofoams
A simple two-step electrochemical method for the fabrication of a new type of hierarchical Sn/SnOx micro/nanostructures is proposed for the very first time. Firstly, porous metallic Sn foams are grown on Sn foil via hydrogen bubble-assisted electrodeposition from an acidulated tin chloride electrolyte. As-obtained metallic foams consist of randomly distributed dendrites grown uniformly on the entire metal surface. The estimated value of pore diameter near the surface is ~35 µm, while voids with a diameter of ~15 µm appear in a deeper part of the deposit. Secondly, a layer of amorphous nanoporous tin oxide (with a pore diameter of ~60 nm) is generated on the metal surface by its anodic oxidation in an alkaline electrolyte (1 M NaOH) at the potential of 4 V for various durations. It is confirmed that if only optimal conditions are applied, the dendritic morphology of the metal foam does not change significantly, and an open-porous structure is still preserved after anodization. Such kinds of hierarchical nanoporous Sn/SnOx systems are superhydrophilic, contrary to those obtained by thermal oxidation of metal foams which are hydrophobic. Finally, the photoelectrochemical activity of the nanostructured metal/metal oxide electrodes is also presented
The impacts of crystalline structure and different surface functional groups on drug release and the osseointegration process of nanostructured
In implantable materials, surface topography and chemistry are the most important in the effective osseointegration and interaction with drug molecules. Therefore, structural and surface modifications of nanostructured titanium dioxide (TiO2) layers are reported in the present work. In particular, the modification of annealed TiO2 samples with —OH groups and silane derivatives, confirmed by X-ray photoelectron spectroscopy, is shown. Moreover, the ibuprofen release process was studied regarding the desorption-desorption-diffusion (DDD) kinetic model. The results proved that the most significant impact on the release profile is annealing, and further surface modifications did not change its kinetics. Additionally, the cell adhesion and proliferation were examined based on the MTS test and immunofluorescent staining. The obtained data showed that the proposed changes in the surface chemistry enhance the samples’ hydrophilicity. Moreover, improvements in the adhesion and proliferation of the MG-63 cells were observed
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