Observation of the Effect of Aging on the Structural Changes of Polyurethane/Polyurea Coatings.

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. The dependence of aging conditions on the physicochemical properties of the tested coating surfaces was thoroughly investigated and characterized by the water contact angle and surface free energy. Adhesion tests were performed after the established aging period. The results show that different aging conditions have a tremendous effect on the appearance and pull-off strength. The coatings that age in a NaCl solution are more affected in terms of their adhesion.

Two Faces of the Screened Bottom Boards-An Ambiguous Influence on the Honey Bee Winter Colony Loss Rate.

We 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 10.7% to 13.9%, and in every year, the overall winter colony loss rate was higher than 10% (which is considered as acceptable in Poland). The study reveals that the use of screened bottom boards was associated with reduced overall loss rate. However, the nature of this relationship was not the same in terms of all types of colony losses: while the use of screened bottom boards was associated with a reduced mortality rate (management-related colony loss rate due to dead colonies) in which the empty hives were observed (colony depopulation syndrome, CDS), it was associated with an increased mortality rate in which the lack of food was observed (starvation). Given that in our study the role of CDS in the overall colony loss rate was 2.5-fold higher than the role of starvation, the final influence of the use of screened bottom boards on the overall colony loss rate turned out to be beneficial. Given the well-known beneficial role of screened bottom boards in varroosis control, they are highly recommended in beekeeping practices in Poland.

ABP1-TMK auxin perception for global phosphorylation and auxin canalization.

The 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 unclear1-3. Whether auxin-binding protein 1 (ABP1) is an auxin receptor has been a source of debate for decades1,4. Here we show that a fraction of Arabidopsis thaliana ABP1 is secreted and binds auxin specifically at an acidic pH that is typical of the apoplast. ABP1 and its plasma-membrane-localized partner, transmembrane kinase 1 (TMK1), are required for the auxin-induced ultrafast global phospho-response and for downstream processes that include the activation of H+-ATPase and accelerated cytoplasmic streaming. abp1 and tmk mutants cannot establish auxin-transporting channels and show defective auxin-induced vasculature formation and regeneration. An ABP1(M2X) variant that lacks the capacity to bind auxin is unable to complement these defects in abp1 mutants. These data indicate that ABP1 is the auxin receptor for TMK1-based cell-surface signalling, which mediates the global phospho-response and auxin canalization.

The psycho-social health of students during first part of COVID-10 pandemy.

INTRODUCTION: 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. OBJECTIVE: The aim of the study was to assess whether and to what extent the restrictions caused by the first wave of SARS-CoV-2 virus pandemics affected emotional state and everyday behavior of students of Polish universities. MATERIAL AND METHODOLOGY: 1,095 students took part in the study - 82.1% of women and 17.9% men, aged 19 and over up to 55 years of age, living mostly in cities. The diagnostic survey method was applied using proprietary questionnaires. The questionnaire was distributed by Internet. The results were processed using the Statistica v.13.3 program with the application of descriptive statistics and tests χ2 and Anova. RESULTS: According to 80% of respondents, the SARS-CoV-2 pandemic is a serious threat for health. During the first wave of the pandemic, students were accompanied mainly by difficult emotions: uncertainty (61%), depression (28.9%), worry (28.7%), nervousness (37.7%) and anger (24%). According to 50.2%, their relations with household members were not changed, while students declaring changes in family relationships pointed to their loosening and limitation. CONCLUSIONS: A significant majority of students stated that the COVID-19 pandemic is a serious threat to health and has a regular interest in epidemiological data concerning coronavirus. Medical students declared the highest risk. The first wave of the pandemic resulted in the intensification of difficult emotions and for half of the respondents changes in the functioning of their family relationships.

Predictors of the Occupational Burnout of Healthcare Workers in Poland during the COVID-19 Pandemic: A Cross-Sectional Study.

The 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. A total of 71.63% (356) of the respondents presented high and moderate levels of emotional exhaustion during the pandemic, 71.43% (355) reported low and moderate job satisfaction levels, whereas 40.85% (203) displayed high and moderate levels of depersonalization. A group of 62.57% (n = 311) demonstrated clear or borderline states of anxiety disorders, while 38.83% (n = 193) suffered from depression or its borderline symptoms. Direct predictors of occupational burnout included: escalating depression; quality of life domains such as the physical, psychological and social; being provided personal protective equipment (PPE) by an employer; age; medical profession; and material status. Emotional exhaustion appeared to be much higher in nursing and 'other' medical professionals than in physiotherapists (p = 0.023). In the times of pandemic, the occupational burnout prophylaxis ought to be focused on early recognition of depression like symptoms and their treatment, as well as providing the staff with PPE and satisfying earnings.

Receptor kinase module targets PIN-dependent auxin transport during canalization.

Spontaneously 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. The auxin-regulated receptor CAMEL (Canalization-related Auxin-regulated Malectin-type RLK) together with CANAR (Canalization-related Receptor-like kinase) interact with and phosphorylate PIN auxin transporters. camel and canar mutants are impaired in PIN1 subcellular trafficking and auxin-mediated PIN polarization, which macroscopically manifests as defects in leaf venation and vasculature regeneration after wounding. The CAMEL-CANAR receptor complex is part of the auxin feedback that coordinates polarization of individual cells during auxin canalization.

Strigolactones inhibit auxin feedback on PIN-dependent auxin transport canalization.

Directional 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. D14 receptor- and MAX2 F-box-mediated SL signaling inhibits the formation of auxin-conducting channels after wounding or from artificial auxin sources, during vasculature de novo formation and regeneration. At the cellular level, SLs interfere with auxin effects on PIN polar targeting, constitutive PIN trafficking as well as clathrin-mediated endocytosis. Our results identify a non-transcriptional mechanism of SL action, uncoupling auxin feedback on PIN polarity and trafficking, thereby regulating vascular tissue formation and regeneration.

Clathrin-mediated trafficking and PIN trafficking are required for auxin canalization and vascular tissue formation in Arabidopsis.

The 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. Major progress has been made in the last years to understand how PINs can change their polarity in different contexts and thus guide auxin flow through the plant. However, it still remains elusive how auxin mediates the establishment of auxin conducting channels and the formation of vascular tissue and which cellular processes are involved. By the means of sophisticated regeneration experiments combined with local auxin applications in Arabidopsis thaliana inflorescence stems we show that (i) PIN subcellular dynamics, (ii) PIN internalization by clathrin-mediated trafficking and (iii) an intact actin cytoskeleton required for post-endocytic trafficking are indispensable for auxin channel formation, de novo vascular formation and vascular regeneration after wounding. These observations provide novel insights into cellular mechanism of coordinated tissue polarization during auxin canalization.

Auxin canalization and vascular tissue formation by TIR1/AFB-mediated auxin signaling in Arabidopsis.

Plant 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. In the current study, we established an experimental system based on the model Arabidopsis thaliana, which exhibits auxin transport channels and formation of vasculature strands in response to local auxin application. Our methodology permits the genetic analysis of auxin canalization under controllable experimental conditions. By utilizing this opportunity, we confirmed the dependence of auxin canalization on a PIN-dependent auxin transport and nuclear, TIR1/AFB-mediated auxin signaling. We also show that leaf venation and auxin-mediated PIN repolarization in the root require TIR1/AFB signaling. Further studies based on this experimental system are likely to yield better understanding of the mechanisms underlying auxin transport polarization in other developmental contexts.

Vascular cambium regeneration and vessel formation in wounded inflorescence stems of Arabidopsis.

Synchronized 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. The cellular and molecular mechanisms of this process are still poorly understood, not the least, because of a lack of a suitable model system. We show that the main genetic model plant, Arabidopsis (Arabidopsis thaliana) can be used to study the canalization during vascular cambium regeneration and new vasculature formation. We monitored localized auxin responses, directional auxin-transport channels formation, and establishment of new vascular cambium polarity during regenerative processes after stem wounding. The increased auxin response above and around the wound preceded the formation of PIN1 auxin transporter-marked channels from the primarily homogenous tissue and the transient, gradual changes in PIN1 localization preceded the polarity of newly formed vascular tissue. Thus, Arabidopsis is a useful model for studies of coordinated tissue polarization and vasculature formation after wounding allowing for genetic and mechanistic dissection of the canalization hypothesis.

Cellular events during interfascicular cambium ontogenesis in inflorescence stems of Arabidopsis.

Development 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. thaliana, leading to the development of interfascicular cambium from differentiated interfascicular parenchyma cells (IPC). These events are as follows: appearance of auxin accumulation, PIN1 gene expression, polar PIN1 protein localization in the basal plasma membrane and periclinal divisions. Distribution of auxin was observed to be higher in differentiating into cambium parenchyma cells compared to cells within the pith and cortex. Expression of PIN1 in IPC was always preceded by auxin accumulation. Basal localization of PIN1 was already established in the cells prior to their periclinal division. These cellular events initiated within parenchyma cells adjacent to the vascular bundles and successively extended from that point towards the middle region of the interfascicular area, located between neighboring vascular bundles. The final consequence of which was the closure of the cambial ring within the stem. Changes in the chemical composition of IPC walls were also detected and included changes of pectic epitopes, xyloglucans (XG) and extensins rich in hydroxyproline (HRGPs). In summary, results presented in this paper describe interfascicular cambium ontogenesis in terms of successive cellular events in the interfascicular regions of inflorescence stems of Arabidopsis.

Allocation of inner cells to epiblast vs primitive endoderm in the mouse embryo is biased but not determined by the round of asymmetric divisions (8→16- and 16→32-cells).

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. Our method of dual labeling of embryos allowed us to distinguish between primary and secondary inner cells contributing ultimately to ICM. Our results show that the presence of two generations of inner cells in the 32-cell stage embryo is the source of heterogeneity within the ICM. We found some bias concerning the level of Fgf4 and Fgfr2 expression between primary and secondary inner cells, resulting from the distinct number of cells expressing these genes. Analysis of experimental aggregates constructed using different ratios of inner cells surrounded by outer cells revealed that the fate of cells does not depend exclusively on the timing of their generation, but also on the number of cells generated in each wave of asymmetric division. Taking together, the observed regulatory mechanism adjusting the proportion of outer to inner cells within the embryo may be mediated by FGF signaling.

Measurement and analysis of the air pressure curve on the rigid lenses by use of ocular response analyzer.

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. METHODS: Examination of air pressure curves was carried out on four plano-convex glass lenses with radii of curvature close to the central corneal radius. Lenses were mounted in front of the air jet of the ORA analyzer. Series of 30 measurements on each lenses were recorded with 20 s and 60 s time interval between measurements. RESULTS were exported to computer and analyzed numerically. RESULTS: RESULTS show much higher reproducibility of pressure curves in every series of measurements in comparison to pressure curves recorded on the patients eye. This demonstrates that ORA produces air pulses with high reproducibility. CONCLUSIONS: Differences in air pressure pulses for the real eye can indicate the dynamics of ocular properties during measurements. Obtained pressure curves are not symmetrical and not well fitted by Gaussian curve. Type of asymmetry of air pressure curves may be explained by viscoelasticity of air.

The availability of HEPA-filtered rooms and the incidence of pneumonia in patients after haematopoietic stem cell transplantation (HSCT): results from a prospective, multicentre, eastern European study.

AIMS 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. DESIGN: A prospective, observational, international study. METHODS: Monitoring cards were distributed within the East Forum EBMT-Nurses Group cooperating centres, and 689 consecutive patients were registered in 1/2010-6/2012. Patients were monitored for 100 days post-transplant. RESULTS: In patients undergoing autologous HSCT, pneumonia developed in 14/400 (3·5%) and was the cause of death in 2/14 (14%) of patients. There was no significant difference in mortality between HEPA-filtered and nonHEPA-filtered groups (4·5% vs. 4·9%, respectively). 239/400 (59%) transplantations were performed in single-bed rooms [190/239 (79%) HEPA-filtered] and 161 (41%) in two-bed rooms [28/161 (17%) HEPA-filtered]. In allogeneic transplantation, pneumonia developed in 24/289 (8·3%) and was the cause of death in 11/24 (45%) of patients. There was no significant difference in mortality between HEPA-filtered and non-HEPA-filtered groups (14% vs. 17%, respectively). 281/289 (97%) of allogeneic transplantations were performed in single-bed rooms [254/281 (90%) HEPA-filtered], and pneumonia was more frequent in patients on corticosteroids and in rooms without HEPA. CONCLUSION: The incidence of pneumonia in the autologous transplantation setting is low. More pneumonia was observed in the allogeneic HSCT group, especially in patients on corticosteroids. There was a trend towards a lower incidence of pneumonia in allogeneic HSCT patients treated in HEPA-filtered rooms. RELEVANCE TO CLINICAL PRACTICE: Autologous HSCT transplantation may safely be performed without HEPA filtration. HEPA filtration might be preferable in patients undergoing allogeneic transplantation.

Rays, intrusive growth, and storied cambium in the inflorescence stems of Arabidopsis thaliana (L.) Heynh.

Arabidopsis 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. However, results presented here concerning the secondary growth in inflorescence stems of Arabidopsis shows that both secondary rays and intrusive growth of cambial cells can be detected, and that, in the interfascicular regions, a storied cambium can be developed.

The risk factors for oral mucositis and the effect of cryotherapy in patients after the BEAM and HD-l-PAM 200 mg/m(2) autologous hematopoietic stem cell transplantation.

PURPOSE: 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. Basic clinical and laboratory variables and their impact on OM were assessed. RESULTS: Age, gender, body mass index, and baseline absolute neutrophil counts were not shown to have any negative impact on OM development. The multivariate analysis revealed oral cryotherapy non-provision as being the most significant predictor for OM incidence (p < 0.0001), followed by BEAM conditioning regimen (p = 0.007), OM in a patient's history (p = 0.002) and lower number of days since the last chemotherapy (p = 0.025). The cryotherapy was remarkably effective both in the single high-dose melphalan 200mg/m(2) conditioning regimen (18% OM in cryotherapy vs. 68% without it, p<0.0001) and in the multidrug BEAM (melphalan 140mg/m(2)) regimen (38% vs. 86%, p=0.006). CONCLUSION: Oral cryotherapy should be implemented into supportive care management in patients treated with high-dose melphalan short-infusion chemotherapy. Large and well-designed randomized trials are necessary to obtain more significant and reliable results and understanding regarding OM risk factors.

Palifermin for patients with haematological malignancies: shifting nursing practice from symptom relief to prevention of oral mucositis.

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. Palifermin (Kepivance) was approved in Europe in 2005 for both prevention and treatment of this painful condition. It works at the epithelial level to help protect cells in the mouth and throat from the damage caused by chemotherapy and radiation, and to stimulate growth and development of new epithelial cells to build up the mucosal barrier. In the pivotal clinical trial, palifermin reduced the incidence, severity, and duration of severe OM. Palifermin was also well-tolerated; common adverse reactions reported included rash, pruritus, erythema, edema, pain, fever, arthralgia, mouth or tongue disorders, and taste alteration. In this article, nurses who are skilled in caring for patients undergoing HSCT review their clinical experience with palifermin, sharing practical advice about its reconstitution, dosing, and administration. By familiarising themselves with the use of palifermin, nurses can influence a shift in clinical practice away from OM symptom management to the more satisfactory situation of protecting patients against severe OM.

Histological analysis of direct somatic embryogenesis in Arabidopsis thaliana (L.) Heynh.

In 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. The analysis showed that at the start of the culture auxin was accumulated in all explant tissues, but from the fourth day onwards its location shifted to the protodermis and subprotodermis of the explant cotyledons. In globular somatic embryos auxin was detected in all cells, with a higher concentration in the protodermis, and in the heart stage its activity was mainly displayed in the shoot, root pole and cotyledon primordia. The embryogenic nature of dividing protodermal and subprotodermal cells accumulating auxin was confirmed by high expression of promoter activity of LEC2 in these cells. Analysis of symplasmic tracer (CFDA) distribution indicated symplasmic isolation between tissues engaged in DSE and other parts of an explant. Symplasmic isolation of somatic embryos from the explant was also detected.