Formation Process Research Articles

Phase separation-competent FBL promotes early pre-rRNA processing and translation in acute myeloid leukaemia.

RNA-binding proteins (RBPs) are pivotal in acute myeloid leukaemia (AML), a lethal disease. Although specific phase separation-competent RBPs are recognized in AML, the effect of their condensate formation on AML leukaemogenesis, and the therapeutic potential of inhibition of phase separation are underexplored. In our in vivo CRISPR RBP screen, fibrillarin (FBL) emerges as a crucial nucleolar protein that regulates AML cell survival, primarily through its phase separation domains rather than methyltransferase or acetylation domains. These phase separation domains, with specific features, coordinately drive nucleoli formation and early processing of pre-rRNA (including efflux, cleavage and methylation), eventually enhancing the translation of oncogenes such as MYC. Targeting the phase separation capability of FBL with CGX-635 leads to elimination of AML cells, suggesting an additional mechanism of action for CGX-635 that complements its established therapeutic effects. We highlight the potential of PS modulation of critical proteins as a possible therapeutic strategy for AML.

Multimodal 2D and 3D microscopic mapping of growth cartilage by computational imaging techniques - a short review including new research.

Being able to image the microstructure of growth cartilage is important for understanding the onset and progression of diseases such as osteochondrosis and osteoarthritis, as well as for developing new treatments and implants. Studies of cartilage using conventional optical brightfield microscopy rely heavily on histological staining, where the added chemicals provide tissue-specific colours. Other microscopy contrast mechanisms include polarization, phase- and scattering contrast, enabling non-stained or "label-free" imaging that significantly simplifies the sample preparation, thereby also reducing the risk of artefacts. Traditional high-performance microscopes tend to be both bulky and expensive. Computational imaging denotes a range of techniques where computers with dedicated algorithms are used as an integral part of the image formation process. Computational imaging offers many advantages like 3D measurements, aberration correction and quantitative phase contrast, often combined with comparably cheap and compact hardware. X-ray microscopy is also progressing rapidly, in certain ways trailing the development of optical microscopy. In this study, we first briefly review the structures of growth cartilage and relevant microscopy characterization techniques with an emphasis on FPM and advanced X-ray microscopies. We next demonstrate with our own results computational imaging through Fourier ptychographic microscopy (FPM) and compare the images with hematoxylin eosin and saffron (HES)-stained histology. Zernike phase contrast, and the nonlinear optical microscopy techniques of second harmonic generation (SHG) and two-photon excitation fluorescence (TPEF) are reported. X-ray attenuation-, phase- and diffraction-contrast computed tomography (CT) images of the very same sample are also presented for comparisons. Future perspectives on the links to artificial intelligence, dynamic studies and in vivo possibilities conclude the article.

Non‐destructive quantitative analysis of melt inclusions in extraterrestrial samples: Case study of chassignite via nanoscale X‐ray computed tomography

AbstractEstimation of the composition of planetary rocks and minerals is crucial for understanding their formation processes. In this study, we present the application of X‐ray nano‐computed tomography (nano‐XCT) for non‐destructive three‐dimensional (3‐D) phase analysis and estimation of phase abundances in rare Martian meteorite samples, specifically chassignite Northwest Africa (NWA) 2737. We determined the most suitable laser power for minimizing artifacts and maximizing phase contrast. By utilizing nano‐XCT, we successfully identified and segmented primary phases in the bulk meteorite sample. Additionally, we were able to locate and segment crystallized silicate melt inclusions within the meteorite. The phase abundances in bulk NWA 2737 and within melt inclusions calculated using nano‐XCT were in good agreement with previous studies that used thin section calculations, demonstrating the reliability of nano‐XCT as a non‐destructive alternative for estimating bulk phase abundances in rare samples. This study develops a benchmarking protocol and demonstrates the efficacy of nano‐XCT as a non‐destructive technique for generating an overview of phase distribution and assemblages of melt inclusions within rare samples. Future research can benefit from combining non‐destructive 3‐D phase assemblage estimations with non‐destructive 3‐D chemical analysis techniques to achieve a fully non‐destructive parental magma composition estimation of rare cumulate samples.

Midterm conversations as co-creation of equitable and inclusive formative assessment

Although assessment of student learning remains a thorny area for co-creation in education, a growing number of researchers and practitioners advocate and enact partnership in formative and summative assessment as part of equity work. In this case study, we join these efforts in reflecting on students’ and our own experiences of the midterm conversation that we use as a key formative assessment structure and process across three co-facilitated courses. The midterm conversation—a partnership among students and instructors as co-teachers—is embedded in course design and curriculum with the goal of advancing, informing, and sustaining our pedagogical commitments. This case illustrates how we practice assessment as dialogue and as emergent understanding. This practice is based on an expectation of diverse learning goals and outcomes and on trust in students’ capacities to direct their learning with reference to their own interests and standards for their work.

Glass transition and crystallization of Se95Te5 chalcogenide glassy semiconductor

The study is dedicated to the investigation of thermo-physical characteristics of Se95Te5 chalcogenide glassy semiconductor during its glass formation and crystallization processes, employing various scanning rates of 5, 10, 15 and 20 K/min in non-isothermal modes through DSC measurement. Analysis of the structural relaxation kinetics involves the Kissinger’s, Augis and Bennett's, as well as Matusita’s approaches. Experimental data yield contains the determination of crucial parameters such as glass transition (𝑇𝑇𝑔𝑔), crystallization(𝑇𝑇𝑐𝑐), and melting temperatures alongside factors like reduced temperature of glass transition (𝑇𝑇𝑟𝑟𝑟𝑟), Hruby’s parameter (𝐾𝐾𝑔𝑔𝑔𝑔), fragility index (𝐹𝐹𝑖𝑖), Avrami exponents (n, m), glass transition (140.24 kJ/mol) and crystallization (Ec = 95.11 kJ/mol) energies, respectively. The results confirm that Se95Te5 chalcogenide system as an efficient glass former. Matusita’s method reveals that the crystallization mechanism (n = 2.51, m = 1.9) corresponds to volumetric nucleation with two-dimensional growth.

Determinants of Citations in Tourism and Hospitality Studies

Citation metrics are frequently used to assess research and rank journals and researchers. Nevertheless, this is still a process with asymmetric information. Tourism research has matured within a small community and through a multidisciplinary scientific paradigm. This paper aims to understand the determinants of tourism research citation patterns. To this end, 101,968 papers within fifteen years (2004-2018) are analysed. Our empirical results suggest that authors’ prestige, the multidisciplinary nature of research, and the impact factor of journals and bibliometric articles will likely increase an article’s citations. This paper represents a step forward in understanding the citation formation process in tourism research.

Absence of female preference and the origin of a unisexual species, the Amazon molly (Poecilia formosa)

AbstractThe role of hybridization as a formative process in evolution has received much attention in the past few decades. A particularly fascinating outcome of hybrid speciation is the formation of asexual hybrid species. The Amazon molly (Poecilia formosa) is such a hybrid and originated from a P. mexicana mother and a P. latipinna father. Consequently, a heterospecific mating must have occurred leading to the Amazon molly, indicating a breakdown of any potential prezygotic isolation between parental species. Here we studied the female mate preferences of extant P. mexicana and P. latipinna from several populations using standard binary choice tests with males of both sexual species that were matched for size. Poecilia mexicana and P. latipinna can be crossed in the lab, however, the offspring are not asexual, but sexual F1s. In our study, we generated F1s and tested their mating preferences with sexual males of both P. mexicana and P. latipinna against F1 males. Overall, our results show that in extant P. mexicana and P. latipinna no female preference for conspecific males was detectable. Consequently, heterospecific matings are possible and not hindered by any apparent behavioral prezygotic isolation. If female preferences in these species were comparable around the time the Amazon molly originated as a hybrid species ca. 100,000 years ago, matings leading to hybrids would be very likely. F1 females also have no discernable mating preferences for either sexual males or F1 males. Such lack of prezygotic behavioral isolation could potentially lead to F2 individuals, backcrosses, and introgression.

The influence of an innovative antibacterial drug of the thiadiazinone class on the virulence factors of bacteria of the phylum Pseudomonadota, which chronically infect patients with cystic fibrosis

Introduction. Infections of the lower respiratory tract by bacteria of the Pseudomonadota phylum: Pseudomonas aeruginosa, Burkholderia spp., Achromobacter spp. are critical to the quality and life expectancy of patients with cystic fibrosis (CF). When the infection is chronic, eradication of bacteria with existing antibacterial drugs is practically impossible. To explore alternative drugs, trials are needed on bacteria isolated from CF patients and characterized using genomic approaches. The objective of our study was a comparative analysis of virulence factors of 6 isolates of bacteria of the Pseudomonadota phylum and testing the efficacy of the innovative drug Fluorothiazinone (FT) in suppressing the pathogenicity of bacteria in vitro. Materials and methods. Isolates of A. ruhlandii ST36, A. xylosoxidans ST555, B. cepacia ST2140, B. gladioli ST2141, P. aeruginosa ST859 and ST198 were examined using whole-genome sequencing and bioinformatics analysis to search for resistance and virulence determinants. The FT drug was tested for its effect on bacteria in in vitro experiments on cytotoxicity on HeLa cells, motility and biofilm formation. Results. Genomic studies have confirmed the arsenal of resistance determinants, especially the efflux systems of bacteria isolated from patients with CF, and the diversity of virulence factors, among which we identified factors in the categories of motility, signals of quorum-sensing systems, secretion systems, exotoxins, as the most essential for the adaptation of bacteria to conditions of the lower respiratory tract. In vitro tests of the FT drug showed its effectiveness in suppressing cytotoxicity (2.6–4.0 times), motility (2.0–3.6 times) and the process of biofilm formation (2.0–7.7 times). Conclusion. For the first time, the effectiveness of the innovative antibacterial drug Fluorothiazinone has been shown against bacteria of the Pseudomonadota phylum, isolated from chronically infected patients with CF, with the described potential of virulence factors.

Designed Additive to Regulated Crystallization for High Performance Perovskite Solar Cell.

It is a crucial role for enhancing the power conversion efficiency (PCE) of perovskite solar cells (PSCs) to prepare high-quality perovskite films, which can be achieved by delaying the crystallization of perovskite film. Hence, we designed difluoroacetic anhydride (DFA) as an additive to regulating crystallization process thus reducing defect formation during perovskite film formation. It was found DFA reacts with DMSO by forming two molecules, difluoroacetate thioether ester (DTE) and difluoroacetic acid (DA). The strong bonding DTE·PbI2 and DA·PbI2 retard perovskite crystallization process for high-quality film formation, which was monitored through in situ UV-vis and PL tests. By using DFA additives, we prepared perovskite films with high-quality and low defects. Finally, a champion PCE of 25.28% was achieved with excellent environmental stability, which retained 95.75% of the initial PCE after 1152 h at 25 °C under 25% RH.

Obtaining and studying the composition, structure and properties of nanophases and nanolayers of CoSi2

ABSTRACT The processes of formation of a thin film of cobalt disilicide on the silicon surface due to the formation of several nuclei of atomic thickness on the surface of the silicon substrate are presented. To create these structures, the ion implantation method was used. The dependence of the depth of penetration of ions into the substrate during ion implantation on temperature and ion dose was determined. In the case of implantation of Co+ ions into Si at room temperature silicon uniformly combines with Co atoms at a depth of 3.5–4 nm, the Co concentration in these layers is 45–50 at. %. Co has been shown to form chemical bonds with Si atoms in the sample containing 40–45 atomic % of Co. When implanting Co+ into Si at 600 K, it was found that the depth of the same added layer is 2.5–3 nm, and CCo forming bonds with Si atoms increases to 85–90%.

Multiple sources of water preserved in impact glasses from Chang'e-5 lunar soil.

The existence of molecular H2O and evolution of solar wind-derived water on the lunar surface remain controversial. We report that large amounts of OH and molecular H2O related to solar wind and other multiple sources are preserved in impact glasses from Chang'e-5 (CE5) lunar soil based on reflectance infrared spectroscopy and nanoscale secondary ion mass spectrometry analyses. The estimated water content contributed by impact glasses to CE5 lunar soil was ~72 ppm, including molecular H2O of up to 15 to 25 ppm. Our studies revealed that impact glasses are the main carrier of molecular H2O in lunar soils. Moreover, water in CE5 impact glasses provides a record of complex formation processes and multiple water sources, including water derived from solar wind, deposited by water-bearing meteorites/micrometeorites, and inherited from lunar indigenous water. Our study provides a better understanding of the evolution of surficial water on airless bodies and identifies potential source and storage pathways for water in the terrestrial planets.

Phantom Attractors in a Single-Degree-of-Freedom Smooth System Under Additive Stochastic Excitation

Phantom attractors in nonlinear systems under additive stochastic excitation have been recently discovered. This paper uncovers the existence of phantom attractors in a single-degree-of-freedom smooth nonlinear equation, which characterizes the vibration of an inextensible beam subjected to lateral stochastic excitation. It also elucidates that the stochastic averaging method, in this context, may lead to qualitatively erroneous probability density functions, identified as one of the reasons why these attractors were previously overlooked. The study then proceeds to analyze the formation process of the phantom attractor and the critical noise intensity associated with it. Subsequently, the key nonlinear term related to the emergence of phantom attractors is identified by observing whether the system still exhibits phantom attractors after the corresponding nonlinear terms are removed. It is revealed that in this system, the presence of phantom attractors is closely linked to the inertia nonlinearity of the hardening type. The system investigated in this paper is simpler compared to previously identified systems capable of generating phantom attractors. This simplicity aids in facilitating research focused on unraveling the general principles behind the formation of phantom attractors.

Application of language tests in university education. Evaluation of a formative process.

La aplicación de pruebas lingüísticas en contextos reales es una competencia fundamental que los estudiantes de los grados en Logopedia y en Educación Primaria deben aprender. El objetivo de esta investigación consiste en comprender y evaluar el proyecto formativo universitario llevado a cabo para que los estudiantes aprendan a aplicar pruebas lingüísticas. El proyecto se divide en tres fases: los estudiantes graban la aplicación de las pruebas lingüísticas, los profesores enseñan el proceso de evaluación, y otros estudiantes analizan y corrigen las pruebas grabadas. Un grupo de 200 participantes completa un cuestionario que incluye preguntas sobre las dificultades y desafíos encontrados y la idoneidad de la práctica. Se valora por separado la enseñanza de pruebas estandarizadas/baterías y la enseñanza de protocolos/registros. Los resultados sugieren que las actividades propuestas son apropiadas. Aunque no se observan diferencias significativas entre los grupos en cuatro variables, surgen disparidades en la comprensión de los vídeos, la toma de notas en las hojas de registro, la elaboración de conclusiones y la redacción de informes. Lo que significa que esta investigación es útil para aquellos docentes que estén interesados en llevar a cabo proyectos formativos con aplicación práctica en el aula y poder así generalizar el proceso formativo a otras universidades.

Three-Body Binary Formation in Clusters: Analytical Theory

Abstract Binary formation in clusters through triple encounters between three unbound stars, ‘three-body’ binary formation, is one of the main dynamical formation processes of binary systems in dense environments. In this paper, we use an analytical probabilistic approach to study the process for the equal mass case and calculate a probability distribution for the orbital parameters of three-body-formed binaries, as well as their formation rate. For the first time, we give closed-form analytical expressions to the full orbital parameter distribution, accounting for both energy and angular momentum conservation. This calculation relies on the sensitive dependence of the outcomes of three-body scatterings on the initial conditions: here we compute the rate of three-body binaries from ergodic interactions, which allow for an analytical derivation of the distribution of orbital parameters of the binaries thus created. We find that soft binaries are highly favoured in this process and that these binaries have a super-thermal eccentricity distribution, while the few hard three-body binaries have an eccentricity distribution much closer to thermal. The analytical results predict and reproduce simulation results of three-body scattering experiments in the literature well.

Electrochemically produced nano-TiO2-coated SiC membranes for photocatalytic water treatment: Preparation, characterization, and hydroxyl radical formation

ABSTRACT Photocatalytically active ceramic flat sheet membranes based on a nanostructured titanium dioxide (TiO2) coating were produced for photocatalytic water treatment. The nano-TiO2 layer was produced by a novel combination of magnetron sputtering of a thin titanium layer on silicon carbide (SiC) membranes, followed by electrochemical oxidation (anodization) and subsequent heat treatment. Characterization by Raman spectra and field emission scanning electron microscopy proved the presence of a nanostructured anatase layer on the membranes. The influence of the titanium layer thickness on the TiO2 formation process and the photocatalytic properties were investigated using anodization curves, by using cyclovoltammetry measurements, and by quantifying the generated hydroxyl radicals (OH•) under UV-A irradiation in water. Promising photocatalytic activity and permeability of the nano-TiO2-coated membranes could be demonstrated. A titanium layer of at least 2 μm was necessary for significant photocatalytic effects. The membrane sample with a 10 μm Ti/TiO2 layer had the highest photocatalytic activity showing a formation rate of 1.26 × 10−6 mmol OH• s−1. Furthermore, the membranes were tested several times, and a decrease in radical formation was observed. Assuming that these can be attributed to adsorption processes of the reactants on the TiO2 surface, initial experiments were carried out to reactivate the photocatalyzer.

Heart-on-a-Chip Model of Epicardial-Myocardial Interaction in Ischemia Reperfusion Injury.

Epicardial cells (EPIs) form the outer layer of the heart and play an important role in development and disease. Current heart-on-a-chip platforms still do not fully mimic the native cardiac environment due to the absence of relevant cell types, such as EPIs. Here, using the Biowire II platform, engineered cardiac tissues with an epicardial outer layer and inner myocardial structure are constructed, and an image analysis approach is developed to track the EPI cell migration in a beating myocardial environment. Functional properties of EPI cardiac tissues improve over two weeks in culture. In conditions mimicking ischemia reperfusion injury (IRI), the EPI cardiac tissues experience less cell death and a lower impact on functional properties. EPI cell coverage is significantly reduced and more diffuse under normoxic conditions compared to the post-IRI conditions. Upon IRI, migration of EPI cells into the cardiac tissue interior is observed, with contributions to alpha smooth muscle actin positive cell population. Altogether, a novel heart-on-a-chip model is designed toincorporate EPIs through a formation process that mimics cardiac development, and this work demonstrates that EPI cardiac tissues respond to injury differently than epicardium-free controls, highlighting the importance of including EPIs in heart-on-a-chip constructs that aim to accurately mimic the cardiac environment.

Catalyst-regulated conversion of p-phenylenediamine-based carbon dots from red to deep-blue emission

Deep-blue emission (＜450 nm) is significant in high-density information storage, solid-state lighting, and vivid displays. However, the carbon dots (CDs) obtained from p-phenylenediamine (pPD) have only red fluorescence, which greatly limits the application and development of pPD-based CDs. As we all know, a catalyst is a substance that can change the rate and pathway of a chemical reaction. Herein, we designed to add a catalyst to realize the conversion of pPD-based CDs from red to deep-blue fluorescence. The emission peak of obtained deep-blue CDs was 440 nm, and the full-width at half-maximum (FWHM) was only 58 nm, with a high color purity. In addition, through in-depth analysis of microstructure and photoluminescence (PL) properties, it is found that the decrease of the sp2-conjugated domain and the graphite N content and the increase in pyridinic N content were the main reasons for the blue shift of the spectra. Based on this, the formation process and mechanism of red and deep-blue CDs were further elucidated. This work not only efficiently realized the design of the deep-blue CDs but also provided a new idea for the luminescence regulation of CDs without changing the raw materials and reaction conditions.

A computational model of the effects of borrower default on the stability of P2P lending platforms

AbstractPeer-to-peer (P2P) lending has attracted scholarly attention because of its economic significance and potential to democratize access to finance. However, P2P lending platforms face many challenges and failures that we need to understand more clearly. We build a computational model to study how borrower default affects P2P platform lending. We show that borrower default disrupts the P2P network formation process and undermines platform stability. Moreover, we find that defaults increase the inequality in accessing funding and provide a rationale for using curation rules, widely used in P2P platforms, in contrast to P2P insurance, which fosters cascading defaults. We also address a new trend in P2P lending platforms in which large companies (institutional investors) play an increasingly important role. We find that the presence of large companies creates a denser network (more loans) but generates a trade-off between making the platform more resilient to cascading defaults and more dependent on specific players. Overall, we explain how borrower defaults affect platform stability and what makes a platform vulnerable, threatening its survival. We discuss research and managerial insights into platform stability and the economic effect of P2P lending platforms.

Infertility psychological distress in women undergoing assisted reproductive treatment: A grounded theory study.

While there exists an ample body of research in international contexts focused on the characterization and quantification of infertility psychological distress, the level of scholarly scrutiny directed towards this phenomenon within the context of China remains scant. To investigate the formation and developmental processes of psychological distress associated with infertility and infertility treatment among women within the Chinese cultural context and to construct a theoretical framework that elucidates this phenomenon. Qualitative approach with grounded theory methodology. This study was conducted within the reproductive medicine department of a tertiary-level hospital located in central China from May to August 2023. Twenty-seven women who experienced infertility and underwent assisted reproductive treatment (ART) were interviewed. The interview sessions spanned durations ranging from 20 min to 1 h and 35 min. Data analysis included open coding, axial coding and selective coding. The study is reported using the COREQ checklist. The infertility psychological distress experienced by women undergoing ART is a socially constructed phenomenon influenced by a dynamic interplay of forces that construct and conciliate it. The formation and progression of infertility psychological distress are rooted in the process of self-construction. A Middle-Ranged Theory titled 'self-reconstruction under the dome of infertility and infertility treatment' (SUDIT theory) was developed to explain this phenomenon. Within this framework, infertility psychological distress manifests across three distinct phases under the gambling ofthe constructive force and conciliative force: (1) distress of disrupting the former self; (2) distress linked to the struggling present self; and (3) the renewed-self harmonized with distress. It is imperative for healthcare professionals and policymakers to acknowledge the socially constructed nature of infertility psychological distress, and proactively implement measures aimed at ameliorating it. No patient or public contribution.

A study of two young multipolar planetary nebulae: Hen 2-73 and Hen 2-96

We perform an infrared (IR) spectral and visible morphological study of two young planetary nebulae (YPNe) Hen 2-73 and Hen 2-96 using archival Spitzer Space Telescope and Hubble Space Telescope (HST) observations to understand their dust properties and nebular structures. High-resolution HST images of these nebulae show several bipolar lobes and ionised tori in the central regions of both objects. The presence of these multi-lobe structures suggests that the formation process of these nebulae is complex. To search for a possible link between the central sources and multipolar appearances of these objects, the Transiting Exoplanet Survey Satellite (TESS) observations are used to examine whether their central stars (CSs) exhibit periodic photometric variations. In the TESS observations, the CS light curve of Hen 2-96 shows a photometric variation with a period of 2.23 hr. The IR spectra of these two YPNe suggest that the nebulae have mixed dust environments, which are associated with the presence of dense tori created by central binary interactions in these objects. Two three-dimensional models are constructed to study the complex nebular structures of the YPNe. These simulations suggest that the number of multipolar YPNe may be larger than observed. In addition, we analyse the spectral energy distributions of these nebulae to study their gas, dust, and photospheric components.