In this study, polyurethane/polyurea coatings were exposed to four different types of aging: aging in the natural environment (NC), accelerated ultraviolet aging (UV), aging in a sodium chloride solution (NaCl), and thermal aging (TC). To monitor the changes that occurred during these processes, the thickness was measured and microscopic and macroscopic observations were conducted continuously. The samples aged under various conditions were then subjected to spectroscopic (FTIR) and thermal (TGA) analysis to determine the possible structural changes in the coatings.
View Article and Find Full Text PDFWe conducted a citizen science survey on the winter honey bee colony losses in Poland from 2017/18 to 2019/20 to determine the influence of the use of screened bottom boards on the winter colony losses due to various causes. A total of 1035 beekeepers with 40,003 colonies reported valid data. The overall winter colony loss rate ranged from 10.
View Article and Find Full Text PDFThe phytohormone auxin triggers transcriptional reprogramming through a well-characterized perception machinery in the nucleus. By contrast, mechanisms that underlie fast effects of auxin, such as the regulation of ion fluxes, rapid phosphorylation of proteins or auxin feedback on its transport, remain unclear. Whether auxin-binding protein 1 (ABP1) is an auxin receptor has been a source of debate for decades.
View Article and Find Full Text PDFIntroduction: In 2020, the world was gripped by a global pandemic caused by a new strain of coronavirus called SARS-CoV-2. Highly contagious, rapidly spreading virus caused massive infections around the world and forced isolation of patients and quarantine of contact persons. Social isolation, caused by the introduction of compulsory distance or resulting from the course of the quarantine process, may result in the loss of emotional ties between individuals, thus leading to the weakening of the social support network.
View Article and Find Full Text PDFThe study aims at analysing the occupational burnout phenomenon, the level of anxiety and depression, as well as the quality of life (QOL) of healthcare workers (HCW) during the COVID-19 pandemic. There were 497 healthcare workers examined across Poland. The Maslach Burnout Inventory (MBI), Hospital Anxiety Depression Scale (HADS) and World Health Organization Quality of Life Instrument Short Form (WHOQOL BREF) were used.
View Article and Find Full Text PDFSpontaneously arising channels that transport the phytohormone auxin provide positional cues for self-organizing aspects of plant development such as flexible vasculature regeneration or its patterning during leaf venation. The auxin canalization hypothesis proposes a feedback between auxin signaling and transport as the underlying mechanism, but molecular players await discovery. We identified part of the machinery that routes auxin transport.
View Article and Find Full Text PDFDirectional transport of the phytohormone auxin is a versatile, plant-specific mechanism regulating many aspects of plant development. The recently identified plant hormones, strigolactones (SLs), are implicated in many plant traits; among others, they modify the phenotypic output of PIN-FORMED (PIN) auxin transporters for fine-tuning of growth and developmental responses. Here, we show in pea and Arabidopsis that SLs target processes dependent on the canalization of auxin flow, which involves auxin feedback on PIN subcellular distribution.
View Article and Find Full Text PDFThe flexible development of plants is characterized by a high capacity for post-embryonic organ formation and tissue regeneration, processes, which require tightly regulated intercellular communication and coordinated tissue (re-)polarization. The phytohormone auxin, the main driver for these processes, is able to establish polarized auxin transport channels, which are characterized by the expression and polar, subcellular localization of the PIN1 auxin transport proteins. These channels are demarcating the position of future vascular strands necessary for organ formation and tissue regeneration.
View Article and Find Full Text PDFPlant survival depends on vascular tissues, which originate in a self-organizing manner as strands of cells co-directionally transporting the plant hormone auxin. The latter phenomenon (also known as auxin canalization) is classically hypothesized to be regulated by auxin itself via the effect of this hormone on the polarity of its own intercellular transport. Correlative observations supported this concept, but molecular insights remain limited.
View Article and Find Full Text PDFSynchronized tissue polarization during regeneration or de novo vascular tissue formation is a plant-specific example of intercellular communication and coordinated development. According to the canalization hypothesis, the plant hormone auxin serves as polarizing signal that mediates directional channel formation underlying the spatio-temporal vasculature patterning. A necessary part of canalization is a positive feedback between auxin signaling and polarity of the intercellular auxin flow.
View Article and Find Full Text PDFActa Bioeng Biomech
September 2015
Purpose: Pressure curves obtained from Ocular Response Analyzer (ORA) differ for the same patient in form and height. In some cases measurements on the subject show significant differences between recorded pressure curves. The purpose of the paper is to examine if the differences result from the corneal properties or from the device operation.
View Article and Find Full Text PDFDevelopment of cambium and its activity is important for our knowledge of the mechanism of secondary growth. Arabidopsis thaliana emerges as a good model plant for such a kind of study. Thus, this paper reports on cellular events taking place in the interfascicular regions of inflorescence stems of A.
View Article and Find Full Text PDFAims And Objectives: To establish the availability of High Efficiency Particulate Air (HEPA)- and nonHEPA-filtered rooms in eastern European transplant centres and to investigate the impact on incidence of pneumonia and mortality after haematopoietic stem cell transplantation (HSCT).
Background: Barrier nursing in HEPA-filtered rooms is generally recommended for patients undergoing HSCT. There are only limited data on the availability of HEPA-filtered rooms and the impact on incidence of pneumonia and mortality.
The epiblast (EPI) and the primitive endoderm (PE), which constitute foundations for the future embryo body and yolk sac, build respectively deep and surface layers of the inner cell mass (ICM) of the blastocyst. Before reaching their target localization within the ICM, the PE and EPI precursor cells, which display distinct lineage-specific markers, are intermingled randomly. Since the ICM cells are produced in two successive rounds of asymmetric divisions at the 8→16 (primary inner cells) and 16→32 cell stage (secondary inner cells) it has been suggested that the fate of inner cells (decision to become EPI or PE) may depend on the time of their origin.
View Article and Find Full Text PDFArabidopsis thaliana is a model plant used in analysis of different aspects of plant growth and development. Under suitable conditions, secondary growth takes place in the hypocotyl of Arabidopsis plants, a finding which helps in understanding many aspects of xylogenesis. However, not all developmental processes of secondary tissue can be studied here, as no secondary rays and intrusive growth have been detected in hypocotyl.
View Article and Find Full Text PDFPurpose: Oral mucositis (OM) still represents a significant complication of hematopoietic stem cell transplantations (HSCT). Observational studies focusing on risk factor definitions are still warranted.
Method: A total of 126 patients participated in this observational study after autologous HSCT with the BEAM and HD-l-PAM 200mg/m(2) conditioning regimens.
Oral mucositis (OM) is an extremely debilitating side effect of certain high-dose chemotherapy and radiotherapy regimens. It is especially prevalent in patients with haematological malignancies who undergo myeloablative therapy and autologous haematopoietic stem cell transplantation (HSCT). Severe erosion of the lining of the oral cavity can make patients' everyday activities, including eating, drinking, swallowing, and talking, difficult or even impossible.
View Article and Find Full Text PDFIn Arabidopsis the in vitro culture of immature zygotic embryos (IZEs) at a late stage of development, on the solid medium containing synthetic auxin, leads to formation of somatic embryos via direct somatic embryogenesis (DSE). The presented results provide evidence that in IZE cells competent for DSE are located in the protodermis and subprotodermis of the adaxial side of cotyledons and somatic embryos displayed a single- or multicellular origin. Transgenic Arabidopsis lines expressing the GUS reporter gene, driven by the DR5 and LEC2 promoters, were used to analyse the distribution of auxin to mark embryogenic cells in cultured explants and develop somatic embryos.
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