Multiple Roles Research Articles

The Rax homeoprotein in Müller glial cells is required for homeostasis maintenance of the postnatal mouse retina

Müller glial cells, which are the most predominant glial subtype in the retina, play multiple important roles, including the maintenance of structural integrity, homeostasis, and physiological functions of the retina. We have previously found that the Rax homeoprotein is expressed in postnatal and mature Müller glial cells in the mouse retina. However, the function of Rax in postnatal and mature Müller glial cells remains to be elucidated. In the current study, we first investigated Rax function in retinal development using retroviral lineage analysis and found that Rax controls the specification of late-born retinal cell types, including Müller glial cells in the postnatal retina. We next generated Rax tamoxifen-induced conditional knockout (Rax iCKO) mice, where Rax can be depleted in mTFP-labeled Müller glial cells upon tamoxifen treatment, by crossing Raxflox/flox mice with Rlbp1-CreERT2 mice, which we have produced. Immunohistochemical analysis showed a characteristic of reactive gliosis and enhanced gliosis of Müller glial cells in Rax iCKO retinas under normal and stress conditions, respectively. We performed RNA-sequencing analysis on mTFP-positive cells purified from the Rax iCKO retina and found significantly reduced expression of Suppressor of cytokine signaling-3 (Socs3). Reporter gene assays showed that Rax directly transactivates the Socs3 promoter. We observed decreased expression of Socs3 in Müller glial cells of Rax iCKO retinas by immunostaining. Taken together, the present results suggest that Rax suppresses inflammation in Müller glial cells by transactivating Socs3. This study sheds light on the transcriptional regulatory mechanisms underlying retinal Müller glial cell homeostasis.

STORIES OF TEACHERS HOLDING MULTIPLE ROLES OUTSIDE TEACHING: CONSEQUENCES AND OPPORTUNITIES

<p><strong>Abstract:</strong></p><p>The research study focused on the stories of teachers holding multiple roles outside teaching: consequences and opportunities, their lived experiences, how they cope with their present situation, and the insights they can share with other teachers who will experience the same experiences they have. This study used the qualitative phenomenological method of research to explore in depth the experiences, coping strategies, and personal insights that can be shared by the participants. The research study purposely identified nine (9) teachers of the senior high schools (6 for the focus group discussion and 3 for the in-depth interview) who are presently holding multiple roles while teaching in the three (3) identified national high schools in Davao Region. The results showed that the participants have their own share of good and bad experiences while holding multiple roles, stating that they encountered time management issues and expressed their struggles and stress but felt opportune with the responsibility they have at present. As their coping strategies, they expressed that resilience is accepting the things to be in the new reality, time and priorities are vital, being driven by it, learning, enjoying and loving the work and consulting and sharing thoughts with peers. Explored three strategies and methods specifically self-determination, perseverance, and sharing ideas and resources with peers. Also revealed are the insights that can be shared with others: do the best you can until you know better, in the midst of difficulty, lies opportunity and teamwork makes dream work.</p><p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/soc/0099/a.php" alt="Hit counter" /></p>

The critical role of anaesthesia in multifaceted care for severe thoracic trauma: A case study

Blunt trauma to the thorax can be viciously dangerous and carries high mortality which warrants aggressive resuscitation and life-saving measures failing which cardiac arrest can occur. We present a case of a polytrauma male patient in the emergency department with diaphragmatic rupture, and bilateral pelvic and clavicular fractures in hypovolemic shock which progressed to cardiac arrest. The patient was immediately resuscitated with Cardiopulmonary and cerebral resuscitation (CPCR) according to Advanced cardiac life support (ACLS) guidelines and stabilized with intravenous fluids and further optimized with blood products. He was operated on for diaphragmatic rupture and shifted to intensive care where he was paralysed and kept on mechanical ventilation for 48 hours treated for severe metabolic acidosis and hemodynamic instability following which he was weaned off successfully. During his stay, he was evaluated for pelvic and clavicular fractures and treated for ICU-related delirium and Methicillin Resistant Staphylococcus infection(MRSA). Our case suggests that diaphragmatic injuries are uncommon but deadly in cases of abdominal forceful trauma because they can result in hemothorax and the movement of intestinal contents into the thoracic cavity. Such cases must be managed with clinical knowledge employing expedient surgical care and the best critical care. This case demonstrates the indispensable and undeniable contributions by anaesthesiologists who assume multiple roles within a hospital setup.

The role identities of discipline-specific facilitators in a multi-tiered professional development program in higher education

ABSTRACT The study explored the emerging role identities of eleven faculty who served as discipline-specific facilitators in a multi-tiered PD program, as well as the affordances and constraints which contributed to the (mis)alignment between the role identity of facilitator and their other roles as faculty. Taking the collective as the unit-of-analysis, we showed that variations occurred in the salience of facilitators’ self-perceptions, beliefs, goals, and action possibilities. These variations occurred within and across their multiple roles including learner, teacher, researcher, middle leader, and peer roles, and were triggered mainly by the (1) in/compatibility of facilitators’ pedagogical beliefs with PD goals and activities, (2) un/confidence in the facilitator role, and (3) absence/presence of institutional support. We suggest that the PD program provides a useful model for professional learning in Higher Education contexts, and that facilitators’ role identities are important tools worthy of further support and exploration.

Electromigration separation of lithium isotopes: The effect of ionic liquid ratios

This study is based on the system of “anodic aqueous solution | crown ether-ionic liquid organic solution | cathodic aqueous solution”, the influence of ionic liquid ratio in organic solution under different voltages on Li+ transport and lithium isotope separation was investigated. It is found that ionic liquids have multiple roles. In addition to improving the conductivity of organic solutions and enhancing Li+ transport capacity between aqueous solution and organic solution through ion exchange. Ionic liquids are even to realize the migration of lithium ions from aqueous solution to organic solution through solvation. There is an obvious synergistic enhancement between ionic liquid solvation and electric field. Based on this, three types of Li+ transport across the aqueous-organic interface are proposed. The influencing mechanism of ionic liquid ratio, voltage on Li+ migration ratio and lithium isotope separation is discussed in detail.

Interactome profiling of Crimean-Congo hemorrhagic fever virus glycoproteins

Crimean-Congo hemorrhagic fever virus (CCHFV) is a biosafety level-4 pathogen requiring urgent research and development efforts. The glycoproteins of CCHFV, Gn and Gc, are considered to play multiple roles in the viral life cycle by interactions with host cells; however, these interactions remain largely unclear to date. Here, we analyzed the cellular interactomes of CCHFV glycoproteins and identified 45 host proteins as high-confidence Gn/Gc interactors. These host molecules are involved in multiple cellular biological processes potentially associated with the physiological actions of the viral glycoproteins. Then, we elucidated the role of a representative cellular protein, HAX1. HAX1 interacts with Gn by its C-terminus, while its N-terminal region leads to mitochondrial localization. By the strong interaction, HAX1 sequestrates Gn to mitochondria, thus depriving Gn of its normal Golgi localization that is required for functional glycoprotein-mediated progeny virion packaging. Consistently, the inhibitory activity of HAX1 against viral packaging and hence propagation was further elucidated in the contexts of pseudotyped and authentic CCHFV infections in cellular and animal models. Together, the findings provide a systematic CCHFV Gn/Gc-cell protein-protein interaction map, but also unravel a HAX1/mitochondrion-associated host antiviral mechanism, which may facilitate further studies on CCHFV biology and therapeutic approaches.

Viability Analysis of Biomphalaria glabrata Hemocytes During Schistosoma mansoni Infection And Glyphosate-Based Herbicide Exposure

Pesticides are chemical agents that have a range of harmful effects on human health and the environment. They can cause drastic changes in natural communities, such as macroinvertebrates, plankton and fish. Snails, including Biomphalaria glabrata, are often present in aquatic communities and have multiple roles in limnic ecosystems. B. glabrata is an intermediate host of several species of helminths of medical and veterinary importance, such as Schistosoma mansoni, the etiological agent of schistosomiasis. The original Roundup® herbicide can affect snails and directly affects S. mansoni hemocytes, cells that act in the snails’ immune defense. Here we analyzed the effect of herbicide exposure on B. glabrata hemocytes divided into four groups: control group, infected-only group, treated-only group and infected+treated group. For this, flow cytometry and Neubauer-chamber counting were used to determine the morphology, viability and lectin expression profiles of hemocytes. We observed that the group infected by S. mansoni and treated with herbicide had a higher concentration of dead hemocytes in relation to the other groups. The treated group showed similar results to the control group, suggesting that the herbicide (Roundup™) alone does not interfere with the snails’ immune system. Regarding cellular-morphological-characterization analysis, hyalinocytes were the cells most commonly found in all groups studied. These findings suggest that S. mansoni infection and exposure to pesticides directly the immune system of the snails, stimulating the production of hemocytes, especially hyalinocytes, which have a high phagocytic power to quell the infection, but with toxic effects on the snail.

The gut microbiome in bullous pemphigoid: implications of the gut-skin axis for disease susceptibility.

Bullous pemphigoid (BP) is an autoimmune blistering disease that primarily affects the elderly. An altered skin microbiota in BP was recently revealed. Accumulating evidence points toward a link between the gut microbiota and skin diseases; however, the gut microbiota composition of BP patients remains largely underexplored, with only one pilot study to date, with a very limited sample size and no functional profiling of gut microbiota. To thoroughly investigate the composition and function of the gut microbiota in BP patients, and explore possible links between skin conditions and gut microbiota, we here investigated the gut microbiota of 66 patients (81.8% firstly diagnosed) suffering from BP and 66 age-, sex-, and study center-matched controls (CL) with non-inflammatory skin diseases (132 total participants), using 16S rRNA gene and shotgun sequencing data. Decreased alpha-diversity and an overall altered gut microbial community is observed in BP patients. Similar trends are observed in subclassifications of BP patients, including first diagnoses and relapsed cases. Furthermore, we observe a set of BP disease-associated gut microbial features, including reduced Faecalibacterium prausnitzii and greater abundance of pathways related to gamma-aminobutyric acid (GABA) metabolism in BP patients. Interestingly, F. prausnitzii is a well-known microbiomarker of inflammatory diseases, which has been reported to be reduced in the gut microbiome of atopic dermatitis and psoriasis patients. Moreover, GABA plays multiple roles in maintaining skin health, including the inhibition of itching by acting as a neurotransmitter, attenuating skin lesions by balancing Th1 and Th2 levels, and maintaining skin elasticity by increasing the expression of type I collagen. These findings thus suggest that gut microbiota alterations present in BP may play a role in the disease, and certain key microbes and functions may contribute to the link between gut dysbiosis and BP disease activity. Further studies to investigate the underlying mechanisms of the gut-skin interaction are thus clearly warranted, which could aid in the development of potential therapeutic interventions.

Teachers' work today: Exploring Finnish teachers’ narratives

This study employs narrative as a theoretical perspective and methodological approach, looking at the current nature of teachers' work from the viewpoint of 25 Finnish basic education teachers. Several categories such as multiple teacher roles and fragmentation of teachers' work, teamwork and multi-professional cooperation, pupils' diverse backgrounds, changed learning skills and behaviour, opportunities and challenges of digitalization, schools' open architecture, and pandemic were identified. These categories illustrate teachers' work today as hectic and changing, involving relational intensification, and as challenging and redefining teachers' identities. The implications for pre- and in-service teachers’ professional development are discussed.

Advanced Hydrogel-Based Strategies for Enhanced Bone and Cartilage Regeneration: A Comprehensive Review.

Bone and cartilage tissue play multiple roles in the organism, including kinematic support, protection of organs, and hematopoiesis. Bone and, above all, cartilaginous tissues present an inherently limited capacity for self-regeneration. The increasing prevalence of disorders affecting these crucial tissues, such as bone fractures, bone metastases, osteoporosis, or osteoarthritis, underscores the urgent imperative to investigate therapeutic strategies capable of effectively addressing the challenges associated with their degeneration and damage. In this context, the emerging field of tissue engineering and regenerative medicine (TERM) has made important contributions through the development of advanced hydrogels. These crosslinked three-dimensional networks can retain substantial amounts of water, thus mimicking the natural extracellular matrix (ECM). Hydrogels exhibit exceptional biocompatibility, customizable mechanical properties, and the ability to encapsulate bioactive molecules and cells. In addition, they can be meticulously tailored to the specific needs of each patient, providing a promising alternative to conventional surgical procedures and reducing the risk of subsequent adverse reactions. However, some issues need to be addressed, such as lack of mechanical strength, inconsistent properties, and low-cell viability. This review describes the structure and regeneration of bone and cartilage tissue. Then, we present an overview of hydrogels, including their classification, synthesis, and biomedical applications. Following this, we review the most relevant and recent advanced hydrogels in TERM for bone and cartilage tissue regeneration.

Biofilm and metallothioneins: A dual approach to bioremediate the heavy metal menace

AbstractMetallothioneins are a class of proteins produced by both prokaryotes and eukaryotes, having low molecular weight and abundant cysteine residues. These proteins play a humongous role in binding, sequestration, and even buffering of the intracellular metal ions. Though they are a wide class of proteins, much of them are yet to be explored. Their metal binding attribute is unique and they form distinctive metal‐thiolate clusters. They have also been known to have ROS scavenging activities due to the presence of the cysteine residues. Phytochelatins also play major roles in metal sequestration pathways. Biofilms on the other hand are clusters of bacterial cells surrounded by an extracellular matrix of polymeric substances secreted by the bacteria themselves. Biofilms play multiple roles, from nutrient sequestration, stress resistance to surface adherence. But lesser explored arenas include assistance in heavy metal trapping and bio‐remediation. Researchers have conducted studies that have demonstrated increased metal trapping, resistance and uptake in biofilm forming strains than non‐biofilm forming mutants. Therefore, this study would explore the dual role of metallothionein and biofilm in their activity of metal sequestration and heavy metal remediation and provide certain insights so as to keenly understand the correlations between the two.

Mr2vec: Multiple role-based social network embedding

Learning representation of networks is increasingly important in social network analysis. Network embedding techniques have a wide range of applications in various downstream tasks, such as node classification and clustering. However, many existing approaches focus on representing each node in a network as a single vector, which is often not practical. In this paper, we propose a multiple role-based social network embedding, called mr2vec, by identifying multiple roles of each node through overlapping clustering and encoding each of them to a vector. Our proposed algorithm transforms a given network into the persona graph using overlapping clustering. Each pair of nodes and roles is mapped to a persona node, enabling us to learn multi-role-based embedding using conventional network embedding techniques. Moreover, we develop a new loss function to have close vector representations when the similarity between the nodes in a persona graph is high based not only on the structural information of node, but also on the role information of nodes. We conducted link prediction experiments within the network to demonstrate the effectiveness of representation learning that takes into account the multiple role information discovered through overlapping clustering of each node. Through extensive experiments on social networks, we have shown that mr2vec achieves higher accuracy than the state-of-the-art algorithms for single- or multi-aspect network embedding.

Synergid cell calcium oscillations refine understanding of FERONIA/LORELEI signaling during interspecific hybridization

Key messagePollen tubes from closely related species and mutants lacking pollen tube MYB transcription factors are able to initiate FER/LRE-dependent synergid cell calcium oscillations.Reproductive isolation leads to the evolution of new species; however, the molecular mechanisms that maintain reproductive barriers between sympatric species are not well defined. In flowering plants, sperm cells are immotile and are delivered to female gametes by the pollen grain. After landing on the stigmatic surface, the pollen grain germinates a polarized extension, the pollen tube, into floral tissue. After growing via polar extension to the female gametes and shuttling its cargo of sperm cells through its cytoplasm, the pollen tube signals its arrival and identity to synergid cells that flank the egg. If signaling is successful, the pollen tube and receptive synergid cell burst, and sperm cells are released for fusion with female gametes. To better understand cell–cell recognition during reproduction and how reproductive barriers are maintained between closely related species, pollen tube-initiated synergid cell calcium ion dynamics were examined during interspecific crosses. It was observed that interspecific pollen tubes successfully trigger synergid cell calcium oscillations—a hallmark of reproductive success—but signaling fails downstream of key signaling genes and sperm are not released. This work further defines pollen tube–synergid cell signaling as a critical block to interspecific hybridization and suggests that the FERONIA/LORELEI signaling mechanism plays multiple parallel roles during pollen tube reception.

"Alphabet" Selenoproteins: Their Characteristics and Physiological Roles.

Selenium (Se) is a metalloid that is recognized as one of the vital trace elements in our body and plays multiple biological roles, largely mediated by proteins containing selenium-selenoproteins. Selenoproteins mainly have oxidoreductase functions but are also involved in many different molecular signaling pathways, physiological roles, and complex pathogenic processes (including, for example, teratogenesis, neurodegenerative, immuno-inflammatory, and obesity development). All of the selenoproteins contain one selenocysteine (Sec) residue, with only one notable exception, the selenoprotein P (SELENOP), which has 10 Sec residues. Although these mechanisms have been studied intensely and in detail, the characteristics and functions of many selenoproteins remain unknown. This review is dedicated to the recent data describing the identity and the functions of several selenoproteins that are less known than glutathione peroxidases (Gpxs), iodothyronine deiodinases (DIO), thioredoxin reductases (TRxRs), and methionine sulfoxide reductases (Msrs) and which are named after alphabetical letters (i.e., F, H, I, K, M, N, O, P, R, S, T, V, W). These "alphabet" selenoproteins are involved in a wide range of physiological and pathogenetic processes such as antioxidant defense, anti-inflammation, anti-apoptosis, regulation of immune response, regulation of oxidative stress, endoplasmic reticulum (ER) stress, immune and inflammatory response, and toxin antagonism. In selenium deficiency, the "alphabet" selenoproteins are affected hierarchically, both with respect to the particular selenoprotein and the tissue of expression, as the brain or endocrine glands are hardly affected by Se deficiency due to their equipment with LRP2 or LRP8.

Ethiodized oil as an imaging biomarker after conventional transarterial chemoembolization

Abstract Conventional transarterial chemoembolization (cTACE) utilizing ethiodized oil as a chemotherapy carrier has become a standard treatment for intermediate-stage hepatocellular carcinoma (HCC) and has been adopted as a bridging and downstaging therapy for liver transplantation. Water-in-oil emulsion made up of ethiodized oil and chemotherapy solution is retained in tumor vasculature resulting in high tissue drug concentration and low systemic chemotherapy doses. The density and distribution pattern of ethiodized oil within the tumor on post-treatment imaging are predictive of the extent of tumor necrosis and duration of response to treatment. This review describes the multiple roles of ethiodized oil, particularly in its role as a biomarker of tumor response to cTACE. Clinical relevance With the increasing complexity of locoregional therapy options, including the use of combination therapies, treatment response assessment has become challenging; Ethiodized oil deposition patterns can serve as an imaging biomarker for the prediction of treatment response, and perhaps predict post-treatment prognosis. Key Points • Treatment response assessment after locoregional therapy to hepatocellular carcinoma is fraught with multiple challenges given the varied post-treatment imaging appearance. • Ethiodized oil is unique in that its’ radiopacity can serve as an imaging biomarker to help predict treatment response. • The pattern of deposition of ethiodozed oil has served as a mechanism to detect portions of tumor that are undertreated and can serve as an adjunct to enhancement in order to improve management in patients treated with intraarterial embolization with ethiodized oil.

Effects of rock outcrops on runoff and erosion from karst slopes under simulated rainfall

AbstractRock outcrops play a crucial role in affecting hydrological and erosion processes on karst hillslopes. However, due to various difficulties in constructing runoff plots on field rocky slopes, previous studies used small metal flumes to simulate outcropped slopes, which greatly differed from the natural rock outcropped slopes. In this study, the effects of rock outcrops on runoff and erosion were studied on karst slopes with natural soil–rock conditions at a larger plot scale (10 m in length × 2.2 m in width, 25° in gradient). Simulated rainfall experiments were conducted on the four runoff plots with different rock outcrop coverages (0%, 5%, 13%, and 42%) under five rainfall intensities (30, 60, 90, 120, and 150 mm·h−1). The study indicated that the rock outcrops complexed the water erosion processes by playing multiple and opposite roles simultaneously. It positively influences water erosion by serving as impermeable surfaces, providing preferential flow paths, and offering flow barriers to hillslopes. Conversely, it can exacerbate erosion by causing increased runoff, concentrating flow paths, and thus intensifying erosion in specific areas. Besides, the effects of these roles varied with the coverage of rock outcrops and rainfall intensity. The main results showed that (i) limited rock outcrop coverage (5% and 13%) increased runoff and erosion, but the opposite was observed on the severe rocky slope (42%). Both “infiltration‐excess” and “saturation‐excess” mechanisms coexisted by turns on karst slopes during rainfall; the break of “saturation balance” tended to occur on the severe rock outcrop slope with abundant soil–rock interface and underground fissures. (ii) Rock outcrops greatly increased the spatial variability and uncertainty of hydrological and erosion processes on karst slopes. The rock outcrops resulted in a larger range of variation in flow velocity and a greater difference among the three slope positions; it also brought more spatial heterogeneity in the development of rill erosion. (iii) Rock outcrops tended to increase flow velocity, and intensify flow turbulence, stream power, and flow energy. The severe rock outcrops significantly reduced the soil erosion induced by the limited soil detachment. This study contributes to a deeper understanding of the mechanisms behind how rock outcrops influence runoff and erosion and provides insights for improving soil erosion prediction in karst regions.

A Review of EMI Research of High Power Density Motor Drive Systems for Electric Actuator

With the global attention given to energy issues, the electrification of aviation and the development of more electric aircraft (MEA) have become important trends in the modern aviation industry. The electric actuator plays multiple roles in aircraft such as flight control, making it a crucial technology for MEA. Given the limited space available inside an aircraft, the power density of electric actuators has become a critical design factor. However, the pursuit of high power density results in the need for larger rated power and higher switching frequency, which can lead to severe electromagnetic interference (EMI) issues. This, in turn, poses significant challenges to the overall reliability of the electric actuator. This paper provides a comprehensive review of EMI in high power density motor drive systems for electric actuator systems. Firstly, the state of the art of electric actuator systems are surveyed, pointing out the contradictory relationship between high power density and EMI. Subsequently, various EMI modeling approaches of motor control systems are reviewed. Additionally, the main EMI suppression methods are summarized. Active EMI mitigation methods are emphasized in this paper due to their advantages of higher power density compared with passive EMI filters. Finally, the paper concludes by summarizing the EMI research in motor drive systems and offering the prospects of electric actuators.

Annexin A5 stabilizes matrix vesicle-biomimetic lipid membranes: unravelling a new role of annexins in calcification

Matrix vesicles are a special class of extracellular vesicles thought to actively contribute to both physiologic and pathologic mineralization. Proteomic studies have shown that matrix vesicles possess high amounts of annexin A5, suggesting that the protein might have multiple roles at the sites of calcification. Currently, Annexin A5 is thought to promote the nucleation of apatitic minerals close to the inner leaflet of the matrix vesicles’ membrane enriched in phosphatidylserine and Ca2+. Herein, we aimed at unravelling a possible additional role of annexin A5 by investigating the ability of annexin A5 to adsorb on matrix-vesicle biomimetic liposomes and Langmuir monolayers made of dipalmitoylphosphatidylserine (DPPS) and dipalmitoylphosphatidylcholine (DPPC) in the absence and in the presence of Ca2+. Differential scanning calorimetry and dynamic light scattering measurements showed that Ca2+ at concentrations in the 0.5–2.0 mM range induced the aggregation of liposomes probably due to the formation of DPPS-enriched domains. However, annexin A5 avoided the aggregation of liposomes at Ca2+ concentrations lower than 1.0 mM. Surface pressure versus surface area isotherms showed that the adsorption of annexin A5 on the monolayers made of a mixture of DPPC and DPPS led to a reduction in the area of excess compared to the theoretical values, which confirmed that the protein favored attractive interactions among the membrane lipids. The stabilization of the lipid membranes by annexin A5 was also validated by recording the changes with time of the surface pressure. Finally, fluorescence microscopy images of lipid monolayers revealed the formation of spherical lipid-condensed domains that became unshaped and larger in the presence of annexin A5. Our data support the model that annexin A5 in matrix vesicles is recruited at the membrane sites enriched in phosphatidylserine and Ca2+ not only to contribute to the intraluminal mineral formation but also to stabilize the vesicles’ membrane and prevent its premature rupture.

An In Situ Fabricated Hydrogel Polymer - Palladium Nanocomposite Electrocatalyst for the HER: Critical Role of the Polymer in Realizing High Efficiency and Stability.

Development of general and simple designs of catalytic electrodes for the hydrogen evolution reaction (HER) is critical. The present work demonstrates the multiple roles played by a hydrogel polymer in the fabrication and activity enhancement of the nanoelectrocatalyst. A nanocomposite thin film of Pd with the insulating hydrogel, poly(2-hydroxyethyl methacrylate) (PHEMA), is fabricated through a facile in situ process, the polymer itself functioning as the reducing/stabilizing agent in the formation of Pd nanoparticles. Pd-PHEMA on Ni foam enables efficient HER in alkaline medium with a low overpotential; the polymer enables the electrocatalysis by its swelling and confinement of the electrolyte. Most significantly, when the electrode is subjected to an optimized cycling protocol, the overpotential decreases steadily, reaching an impressively low value of 36 mV (@10 mA cm-2 ). A low Tafel slope (68 mV dec-1 ), high exchange current density, Faradaic efficiency and TOF (3.27 mA cm-2 , 99 %, 122.7 h-1 ), and extended stability are achieved. Detailed investigations reveal the active role of the polymer in the evolution of the nanocatalyst, itself undergoing favorable morphological changes. The study illustrates the widened scope for developing efficient and stable catalytic electrodes with hydrogel polymers and unique features that promote the generation of green hydrogen.

50세 이상 성인학습자의 박사과정 학습 경험, 학습 동기, 학습 실천의 의미

Objectives This study is to identify the meaning of doctoral program learning experience, learning motivation, and learning practice of adult learners aged 50 and older.
 Methods Individual in-depth interviews were conducted with seven doctoral students aged 50 or older who vol-untarily expressed their willingness to the participation. For thematic analysis, the interview contents were tran-scribed, and three researchers selected meaningful topics through the process of coding, categorization, and classification through continuous elaboration and revision to derive themes, sharing opinions, and coordinating.
 Results As a result of the analysis, under the three major themes of ‘doctoral course learning experience’, ‘learning motivation’, and ‘meaning of learning Practic’, ‘difficulty of late adult learning’, ‘sense of stability in career’, ‘desire for internal growth' fulfillment’, ‘external growth and development’, ‘recognition of the need for change’, ‘new challenges for dreams’, ‘preparation for the future’, ‘learning to improve the quality of life’, ‘learning to prac-tice good influence’, ‘learning for self-realization’, and ‘learning to continue’ were derived.
 Conclusions In a rapidly aging society, adult learners who choose doctoral programs at the turn of the age of 50 can feel the stability and satisfaction of their social role needs through the learning process, even though they ex-perience the difficulties of multiple roles of work, family, and learning. Their doctoral course learning practice was most motivated to achieve their personal and social growth in the changing societal context. In other words, they revealed that they not only plan their future lives by cultivating expertise in their field through late learning, but also have the meaning of leading a community life and contributing to society as members of our society.