bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical modeling of the combined heat supply system of the solar house
Authors: Khamraev S.I. , Kodirov J.R. , Arabov J.O. , Mavlonov U.M. , Rakhimov N.Z.
Published: May 2024

Today, improving energy efficiency in residential heat supply systems, saving fuel and energy resources, and increasing the efficiency of using devices based on renewable energy sources is an urgent issue. The aim of the article is to develop a mathematical model of the heat balance of one-story country houses based on the use of solar energy in a non-stationary mode and conduct theoretical research. The heat balance scheme of the solar house with autonomous heat supply and the electric-heat scheme of the physical model are proposed. Based on the proposed schemes, a mathematical model and calculation algorithm of the heat balance of a one-story rural house of the research object in non-stationary mode were developed, based on the mathematical modeling, the influence of the heat capacity of the wall structure on the temperature regime of the building was studied. The main temperature characteristics, which analyzed the change of the indoor air temperature of the building depending on the ambient temperature, were built on the basis of the MATLAB/SIMULINK program. The mathematical model of the building’s heat balance in dynamic mode and the obtained calculation results are recommended for use in the development of energy-efficient solar houses.
Technical and economic analysis, calculation and justification of hydrogen production through solar thermochemical reactor in Republic of Uzbekistan
Authors: Akhmadov Kh.S. , Nazarova N.M. , Juraev A.R. , Avezov I.Y.
Published: May 2024

In this study, the economic viability of hydrogen production in the Republic of Uzbekistan was evaluated. Specifically, the costs and breakeven prices for hydrogen production were analysed across five selected regions within the Republic. The analysis focused on the potential reduction in production costs achievable through investor engagement. Among the regions studied, Tashkent exhibited the lowest production cost at 1.2 USD/kg. In scenarios devoid of investor participation, the levelized cost of hydrogen (LCOH) was estimated to range between 1.25 and 2.00 USD/kg. The inclusion of investors was found to yield an average profit of 0.35 USD/kg across the Republic. The findings suggest that with an average production cost of 1.2 USD/kg, hydrogen production in the Republic of Uzbekistan could be economically viable.
Multicriteria fuzzy statistical analysis of biogas energy systems dependability
Authors: Lomazov Alexander V. , Lomazov Vadim A. , Klyosov Dmitriy N. , Miroshnichenko Irina V. , Zuev Nikolay P.
Published: May 2024

The work is devoted to the problems of assessing the dependability of autonomous energy systems with biogas type of electrical generation. The purpose of the work is to develop an intelligent tool for multi-criteria dependability assessment, taking into account the statistical uncertainty of individual indicators. A three-level hierarchy (according to the degree of generalization) of dependability indicators, represented by statistical (at the lower level) and fuzzy linguistic (starting from the second level) variables, has been developed. It is proposed to implement the transition from statistical values of lower-level indicators to numerical values of second-level indicators using an artificial neural network. Fuzzification of second-level indicators was carried out using L. Zadeh’s z-number apparatus, which allows taking into account statistical uncertainty. To determine the integral dependability indicator (top of the hierarchy) based on second-level indicators, it is proposed to use the Mamdani fuzzy inference algorithm. The constructed procedure for determining the level of dependability allows us to obtain data for making scientifically based decisions when operating biogas energy systems.
Ecological monitoring of aquatic and terrestrial ecosystems based on the distribution of model groups of living organisms
Authors: Kozminov Sergey , Krapivina Elena , Paritov Anzor , Khadzegova Svetlana , Lukyaeva Zuleikha
Published: May 2024

The paper presents the results of the analysis of the use of living organisms as bioindicators and model groups in the ecological monitoring of natural ecosystems in various landscapes. The results of the analysis of the distribution of dragonflies and macromycetes in aquatic and terrestrial ecosystems, the taxonomic composition of populations and individual communities showed a relationship with physical-geographical and natural-climatic conditions. The distribution of dragonflies is heterogeneous, associated with the characteristic features of water bodies and terrestrial biotopes, the nature of saprobity and plant formations. The distribution of macromycetes is determined by substrate specialization, the composition of the dendroflora of mycobiotes of different altitudinal zones and belts. Features of the distribution, allows you to use these groups of organisms as model objects for the organization of environmental monitoring.
Study of changes in the induced wave field in mining waste storage facilities
Authors: Dyakov Andrey
Published: May 2024

An integrated approach to analyzing changes in the induced wave field in mining waste storage facilities for mineral waste is considered to localize potentially dangerous zones in the body of bulk structures using georadar sounding. It has been established that the zone of possible water saturation of rocks is perceived by the georadar signal as a transition to a medium with a higher dielectric constant and is reflected by the maximum amplitude of the signal. The boundaries of water saturation zones are not always sharply defined, but change smoothly depending on the degree of water saturation from a natural state unsaturated with moisture to complete saturation of soil pores. During GPR sounding, below the expected zone of water saturation, the soil structure is noticeably smoothed out, where, due to increasing attenuation, the signal amplitude sharply drops, which manifests itself in a noticeable decrease in the contrast of the wave pattern of the radargram. The use of intra-method integration by profiling on a permanent base and a common depth point with simultaneous synchronization of groundwater level measurements in a piezometer made it possible to identify and identify zones of increased water saturation in the dam body.
Bioresource potential of sea buckthorn phytocenes in the conditions of Southern Siberia
Authors: Khovalyg Nadezhda
Published: May 2024

The work presents the results of a long-term analysis of the resource potential of sea buckthorn phytocenoses of Tuva growing in arid conditions of Southern Siberia. The biological potential of sea buckthorn, which has environmental, consumer and economic significance for the region, has been identified. Also, up to 95.0% of the area of sea buckthorn in the natural environment was identified in Tuva. Plants growing in natural and artificial conditions have different yield indicators. On the economic side, products are presented in the form of additional income for the population. The growing conditions that form fruits depend on the ecological state of the plants. We conducted our research within the Republic of Tyva, an economically underdeveloped territory of Southern Siberia. The growing conditions are not similar in characteristics. In total, sea buckthorn grows in its natural environment in 12 administrative divisions of the district. Options for artificial phytocenoses in the Botanical Garden of Tuva State University, grown in dry steppe conditions, require intensification and adherence to correct agricultural technology. When grown in agroecosystems, constant watering of the plants is required in the first half of the growing season. To increase, most fully realize and protect the bioresource potential of sea buckthorn in the conditions of Tyva, it is advisable to carry out work on growing sea buckthorn and recommendatory types of work have been proposed.
Improvement of the technical and economic indicators of oil production
Authors: Mayilov Rauf , Bakhshaliyeva Sevinj , Imanova Tunzala
Published: May 2024

To understand the stated theory and technical specifications, a specific problem of optimizing experimental studies of the gas-lift process has been solved: the process of measuring the parameters of a gas-lift well necessary for solving and plotting the dependence of the well flow rate on the flow rate of injected gas is given. The measurements consisted of three main components (stages of types of measurements). It is indicated that all components are interconnected, therefore, an error in readings at any one stage leads to a violation of the relationship curve between the well flow rate (lifter supply) and the flow rate (volume) of injected gas. The reliability of the instrument’s readings can be increased by duplicating each measurement step by step. As a result of the research, a method was indicated to improve the technical and economic indicators of the gas-lift method of oil production.
Oxidative desulfurization of VGO using carbon nanostructures created by NTP-pyrolysis of fuel oil
Authors: Bodrikova E.R. , Titov E.Yu. , Bodrikov I.V.
Published: May 2024

Desulfurization of heavy oil fractions is complicated due to the high content of stable polycyclic systems including thiophene ring. Therefore, there is a need to develop new efficient and cost-effective desulfurization methods. The catalytic activity of carbon structures obtained by plasma-chemical pyrolysis of hydrocarbon feedstock (fuel oil, non-hydrorefined vacuum gas oil and catalytic cracking residue) was investigated in this work. The catalytic activity of carbon structures was investigated in relation to the process of oxidative desulfurization of light vacuum gas oil. The oxidation process was carried out at 60°C using ultrasonic dispersion for 1 minute. The oxidation products were extracted with furfural. As a result of oxidation followed by extraction, the sulfur content in gas oil decreased from 0.64 to 0.24% wt.
Tools for ranking objects of the mineral resource complex based on ontology
Authors: Dadykin Valery , Dadykina Olga , Kondratenko Sergey
Published: May 2024

Mineral resources form the basis for the development of the vast majority of industries. At the same time, most of them are non-renewable. To determine promising exploration activities in conditions of limited human, financial, and sometimes technical resources, it is necessary to take into account a large number of factors when setting exploration tasks for the reproduction of mineral resources. To solve problems with relatively weak formalization, it is customary to use the mathematical apparatus of fuzzy logic in decision support systems. However, it must be based on an ontological model that will contain the interrelationships of the elements of the system and allow you to find implicit relationships between them. In this paper, based on the mathematical apparatus of fuzzy logic and the Mamdani method, it is proposed to form an ontology of geological and economic monitoring in relation to a mineral resource facility (MRF), an industrial raw materials hub (IRMH) and an administrative entity. As a result, using the Reasoner component built into Protege, indicators of geological and economic monitoring, taxonomic units and the frequency of information collection for designing a decision support system in the geological industry were determined. It is possible to create such a convergence, taking into account the heterogeneity of data storage systems, on the basis of an ontological model. The advantage of using ontology is the high level of this tool flexibility, taking the form of heterogeneous data integration within a single storage system. This article attempts to use ontological models framework together with artificial intelligence for the geological subject area in terms of solid minerals, particularly common ones, and ground waters.
Studies of the hydrodynamic properties of the formation of an oil and gas condensate field
Authors: Khusnutdinova Regina , Almukhametova Elvira , Yusupova Liliya , Yalovega Danil
Published: May 2024

This paper presents the experience of well testing conducted by several geological associations. The studies were conducted to assess the characteristics of productive formations, such as hydroconductivity, productivity, saturation pattern and operating mode. Various methods and equipment were used, including various types of drilling rigs and drills. Some disadvantages of the tests are also described, such as the erroneous choice of perforation intervals or poor-quality gas condensate studies. The data on the tools and techniques used, as well as the results of studies on stationary and unsteady filtration modes are presented. The findings of the study will help to improve understanding of the geological characteristics of the formations and improve production efficiency.
On the development of the emitter assembly of an acoustic downhole device
Authors: Gilmanova Alfiya , Filimonov Oleg , Galiullina Irida , Mukhamadeev Eduard , Guseinova Elena
Published: May 2024

The article considers narrow-band and broadband variants of the acoustic logging method, shows the advantages and disadvantages of existing radiators, describes the requirements for acoustic radiators of borehole devices for a wide frequency range from 0.5 to 40 kHz, shows the experimental and theoretical justification of the designs of radiator assemblies and the basic requirements for calculations. The result of the work is an upgraded design of the radiator assembly, which ensures the operation of broadband acoustic logging devices, described in detail in this article.
Geoepidemiology, seroprevalence and factors associated with Toxoplasma gondii infection in domicilied cats from Paraíba (Brazil)
Authors: Fernandes Ana Letícia Pereira , de Melo Alves Mariana , Silva Jordania Oliveira , Bison Ividy , de Castro Tavares Silva Ariana , Parentoni Roberta Nunes , dos Santos Jose Romulo Soares , Feitosa Thais Ferreira , Vilela Vinícius Longo Ribeiro , de Lima Brasil Arthur Willian
Published: May 2024

Toxoplasma gondii is a parasite responsible for toxoplasmosis, an emerging and often neglected zoonosis in South America, particularly Brazil. Felines, the only definitive hosts, excrete oocysts in their feces, potentially infecting all homeotherms. Domestic cats are primarily responsible for contaminating human environments with these oocysts. Monitoring their populations is therefore essential to ensure proper toxoplasmosis prophylaxis. The aim of this study was to estimate the prevalence of T. gondii and exposure factors in a population of owner cats in the city of João Pessoa, Paraíba, Brazil. A total of 267 blood samples were collected from domestic cats aged between 1 and 15 years and tested with an immunofluorescence antibody test. The seroprevalence of antibodies against T. gondii was only 17.22% (46/267 individuals). This result therefore suggests a low contribution of domestic cats to T. gondii contamination of the urban environment. The cats’ age and living environment were identified as risk factors for cat exposure to T. gondii.
Yoga verbessert das Gleichgewicht bei Multipler Sklerose – Wissenschaft nachgefragt
Authors: Veit Katrin
Published: May 2024

Die angehenden Physiotherapeuten Luis Schwarz und Kay Mosblech gingen in einer ihrer Hausarbeiten der Fragestellung nach, ob sich Yoga bei Multipler Sklerose auf das Gleichgewicht auswirkt. Sie fanden positive Effekte auf die Gleichgewichtsfähigkeit und fordern einen Yoga-Übungsleitfaden mit konkreten Übungen und Parametern.
Liebevolles Miteinander – Freiwilligenarbeit in Guatemala
Authors: Stampa Leonie
Published: May 2024

2018 beendet Leonie Stampa ihre Physiotherapieausbildung. Anstatt ihre erste Stelle anzutreten, packt sie ihre Koffer und fliegt über eine deutsche Organisation nach Guatemala, um die dortige Physiotherapie kennenzulernen. Vor kurzem kam sie nun schon von ihrem zweiten Aufenthalt in der Albergue Hermano Pedro, einer Einrichtung für Menschen mit neurologischen Einschränkungen, zurück.
Hochintensiv gegen Schmerzen – Physiotherapie bei axialer Spondylarthritis
Authors: Grenier Jean-Pascal
Published: May 2024

Menschen mit axialer Spondylarthritis klagen oft über chronisch entzündlich Rückenschmerzen. Gleichzeitig treten Gelenkschwellungen, Sehnen- und Bänderentzündungen auf. Mitunter sind auch Augen, Haut und Darm betroffen. Jean-Pascal Grenier will mehr Bewusstsein für die Anzeichen sowie für therapeutischen Maßnahmen schaffen. Für die Therapie empfehlen sich regelmäßige körperliche Aktivität, intensives Krafttraining, ein gesunder Lebensstil sowie der sofortige Rauch-Stopp.
Influence of Hypoxic Condition on Cytotoxicity, Cellular Migration, and Osteogenic Differentiation Potential of Aged Periodontal Ligament Cells
Authors: Jaiklaew Sukrit , Tansriratanawong Kallapat
Published: May 2024

Objective This study aimed to investigate and compare the influence of hypoxic conditions on cytotoxicity, cellular migration, and osteogenic differentiation of aged periodontal ligament (PDL) cells.

Materials and Methods Isolated human PDL cells from aged and young subjects were cultured under hypoxic conditions, which were treated with hydrogen peroxide (H2O2) (0, 25, 50, 100, 200, and 500 µM). To assess cytotoxicity, lactate dehydrogenase release was determined by the optical density at 490 nm, and the percentage of cell death was calculated. An in vitro wound healing assay was performed over 24 to 48 hours for cellular migration determination. Osteogenic differentiation was determined by alizarin red staining and osteogenic gene expression, including the expression of runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and osteopontin (OPN).

Results There was a significant difference in the percentage of cell death with high hypoxic condition (200 and 500 µM) compared to low hypoxic conditions on both day 1 and 2. The highest cellular migration was depicted at 50 µM in both young and aged groups of the in vitro wound healing assay. Osteogenic gene expression of RUNX2 in the aged group was increased at 25 and 50 µM hypoxic condition at day 7, but the expression was gradually decreased after 14 days. On the contrary, the expression of ALP and OPN in the aged group was increased at day 14. Only OPN had been found to be statistically significantly different when compared with gene expression at day 7 and 14 (p < 0.05). The results showed no statistically significant differences when compared with the young and aged groups in all genes and all concentrations.

Conclusion The concentration of low hypoxic condition (25–50 µM) was proposed to promote cell viability, cellular migration, and osteogenic differentiation in aged PDL cells. We suggested that the potential of aged PDL cells for use in cell therapy for periodontal regeneration might possibly be similar to that of young PDL cells.
Assessing the status quo of international employees’ adjustment research, 1990–2022: a review and future research agenda
Authors: Baneviciene Irma , Andresen Maike , Kumpikaite-Valiuniene Vilmante
Published: May 2024

This study aims to comprehensively review scientific journal articles related to the adjustment of international employees within the management and business domain from 1990 to 2022. The study seeks to identify trends and patterns in research topics and to propose a future research agenda. To achieve this, we analysed 222 articles from the Web of Science Core Collection database through two main steps: (1) a bibliometric analysis to track the field’s evolution over time and (2) a content analysis of abstracts to examine covered topics and pinpoint research gaps. Our findings indicate that the theory surrounding the adjustment of international employees is still in the process of maturation, with several potential areas for future research emerging. The analysis reveals that factors influencing adjustment are the most extensively researched for assigned expatriates, leaving other international employees relatively under-researched. Moreover, quantitative research emerged as the most prevalent methodological approach among the included studies. Most study samples predominantly consisted of individuals moving between Asia, Europe, and North America, underscoring the significance of Africa—characterised by substantial migration flows within the region—as a focal point for future adjustment research. Moreover, individual-, organisation-, and country-related antecedents of international employees’ anticipatory and in-country adjustments were analysed to present conclusions for future research. This study supplements the domains of international human resource management and international business by identifying research priorities concerning the adjustment of international employees and outlining an agenda for further research.
Short notes: Inversion of exchange interaction sign of Nd3+ excited states and its manifestation in optical absorption spectra of NdFe3(BO3)4 crystal
Authors: Kachur I. S. , Kurnosov V. S. , Piryatinskaya V. G.
Published: May 2024

Experimental studies and group-theoretical analysis of low-temperature optical absorption spectra of neodymium ferroborate crystal NdFe3(BO3)4 were carried out. It was shown that the sign of exchange interaction with the iron subsystem in an excited state of Nd3+ can be different from that in the ground state.
Using machine learning to explore the full potential of porous materials
Authors: Thompson Avery
Published: May 2024

Advanced tools can help sift through nearly endless combinations to find materials with desired properties.
Double pulse all-optical coherent control of ultrafast spin-reorientation in an antiferromagnetic rare-earth orthoferrite
Authors: Khokhlov N. E. , Dolgikh A. E. , Ivanov B. A. , Kimel A. V.
Published: May 2024

A pair of circularly polarized laser pulses of opposite helicities are shown to control the route of spin reorientation phase transition in the rare-earth antiferromagnetic orthoferrite (Sm0.55Tb0.45)FeO3. The route can be efficiently controlled by the delay between the pulses and the sample temperature. Simulations employing previously published models of laser-induced spin dynamics in orthoferrites failed to reproduce the experimental results. We suggest that the failure is due to neglected temperature dependence of the antiferromagnetic resonance damping in the material. Taking into account the experimentally deduced temperature dependence of the damping, we obtained good agreement between the simulations and the experiment.
Polypyrrole film formation using DC biasing of substrate in in-solution plasma process
Authors: Jang Hyojun , Jung Eun Young , Kim Jae Young , Tae Heung-Sik
Published: May 2024

Beyond the existing in-solution plasma (iSP) process used for nanoparticle synthesis, polymer film synthesis has recently been demonstrated via iSP, which occurs at a specific cycle in a substrate with electrical potential. Herein, we propose an iSP reactor designed to tune the characteristics of polypyrrole (PPy) films by applying varied DC biases to the substrate during the solution plasma process. Applying DC bias to the substrate notably enhances the iSP during the negative cycle, thereby generating ionic precursors from pyrrole monomers for PPy film formation. These films demonstrated morphological variances as a function of the applied VDC. At a low voltage (VDC = 0.5 kV), a uniform film was formed via a layer-by-layer growth mechanism, and as the voltage was increased, the film exhibited a structured morphology. Specifically, at VDC = 0.5 kV, the PPy film was successfully coated onto a finely patterned electrode. The proposed iSP process, under specific DC biasing conditions, enables polymer coating without necessitating additional chemicals, catalysts, or masks. This method holds potential for a wide range of applications.
Situationally-triggered metaphor as political argument
Authors: Augé Anaïs
Published: May 2024

This paper proposes to investigate the public responses to situationally-triggered metaphors as these have been
observed in political argumentation. Situationally-triggered metaphors occur when a nonmetaphorical connection is made between the
metaphor and an aspect of the relevant situational context. The question addressed in this research is: how are such metaphors
perceived by the public when these form part of the political argumentation? To answer this question, the study focuses on a
particular instance of political situationally-triggered metaphor i.e., Boris Johnson’s “James Bond” metaphor produced during
COP26. The paper draws on Critical Metaphor Analysis and Deliberate Metaphor Theory to analyse the public comments and reactions
posted on the social media platform Twitter in response to the politician’s arguments. The analysis reveals that most of the
public responses exploit the “James Bond” metaphor to dispute Johnson’s self-identification to the fictional character and provide
meta-arguments that revolve around the politician’s misuse of metaphors. In contrast, responses that exploit the metaphor to
convey political arguments or endorsement are much more limited. It is thus argued that situationally-triggered metaphors not only
represent a political rhetorical device, but they are also effective political tools to shift public attention towards discursive
patterns instead of arguments presented in discourse.
Photon counting based pump-probe technique for quantitative characterization of fluorescence in a lock-in free detection manner
Authors: Rehman Khalil Ur , Das Subir , Kao Fu-Jen
Published: May 2024

The stimulated emission (SE) signal in pump-probe experiment is conventionally measured with lock-in detection to differentiate the weak signals from the relatively large background of spontaneous emission and probe beam. Therefore, direct characterization of signal strength are often major limiting factors in terms of noise, speed, and data acquisition. In contrast, photon counting allows direct quantification of signal strength, while synchronized pump-probe pulse enables precise timing and the separation of signals accordingly. Herein, the SE based pump-probe method is combined with time-correlated single-photon counting to investigate the ultrafast photochemical parameters, digitally and quantitatively. As a proof-of-concept, our technique is applied to investigate, fluorescence lifetime

(
τ
)

∼
3.71

ns

, optical absorption cross-section

(

σ

abs

)

∼
1.23
×

10

−
16

c

m

2

, and the SE cross-section

(

σ

SE

)

∼
2.22
×

10

−
17

c

m

2

, of a fluorescent dye (ATTO 647N) quantitatively. The experimental results are also compared with theoretical photon statistics to further justify the advantages including experimental and statistical critical molecular dynamics parameters extraction with excellent high accuracy.
O16 Understanding the pleiotropic effects of the Rho-kinase inhibitor Y-27632 on human keratinocytes
Authors: Flynn Benjamin , Glallacher Kelli , Walko Gernot
Published: May 2024

Introduction and aims

Successful epidermal transplant generation depends on sufficiently high numbers of self-renewing stem cells that give rise to clonal colonies termed ‘holoclones’. Treatment with Y-27632, a nonspecific Rho-kinase 1/2 inhibitor, conditionally immortalizes epidermal keratinocyte cultures. However, the pleiotropic signalling mechanisms downstream of Y-27632 remain largely unexplored. We have therefore characterized the effects of continuous long-term Y-27632 treatment on chromatin regulation, and investigated whether Y-27632 reprogrammes a holoclone-like state.

Methods

Neonatal foreskin-derived human epidermal keratinocytes were cultured from passage p5 to p30, with or without Y treatment. Samples were collected for RNA sequencing analysis from progenitor-enriched middle passage cells (p5, MPK), progenitor-depleted late-passage cells (p8, LPK) and Y-treated cells at p8 (LPK-Y). Samples were also collected for assay for transposase-accessible chromatin (ATAC)-Seq analysis to assess open and closed chromatin regions.

Results

Untreated cultures became depleted of proliferating cells by p11, whereas Y maintained a highly proliferative culture up to p30 and beyond. Y withdrawal at p11 resulted in rapid loss of proliferative capacity within a single passage. ATAC-Seq identified 196 differentially regulated chromatin sites in MPK vs. LPK. Y treatment maintained accessibility in approximately 40% of these MPK-enriched chromatin regions. Approximately 3000 differentially expressed genes (DEGs) were identified in MPK vs. LPK, while Y treatment induced approximately 11 000 DEGs. Activated genes in LPK-Y were enriched for a holoclone signature, with no evidence for activation of a precancerous transcriptome. Y treatment altered the expression of various genes associated with amino acid metabolism, enabling cells to overcome serine/glycine autotrophy.

Conclusions

Y acts by preserving accessibility of progenitor-enriched chromatin sites and further reprogrammes the keratinocyte transcriptome towards a more holoclone-like state. However, keratinocytes retain a ‘memory’ of their doubling number, which is conditionally suppressed by Y. The observed global transcriptomic changes are indicative of the highly pleiotropic nature of the Y-induced signalling changes, warranting further deconvolution.
O17 Highly efficient base editing of homozygous and heterozygous COL7A1 variants in fibroblasts from patients with recessive dystrophic epidermolysis bullosa using adenine base editor 8e mRNA system delivered via novel lipid nanoparticle formulations
Authors: Guri Ina , Brooks Imogen , Alrokh Yara , Kazamizadeh Aidni , Graham Carina , Hart Steven , McGrath John , Jackow Joanna
Published: May 2024

Introduction and aims

Adenine base editors (ABEs) present an attractive approach to gene editing in the inherited blistering disease recessive dystrophic epidermolysis bullosa (RDEB), which Results from pathogenic variants in COL7A1. We previously showed that ABE8e, a new ABE variant, confers remarkable efficiency (94.6%) and a favourable safety profile in correcting variants and restoring collagen 7 (C7) expression when electroporated into RDEB fibroblasts. With a goal to develop topical base editing creams, we now explore use of lipid nanoparticle (LNP)-encapsulated ABE8e mRNA system to edit two distinct variants in RDEB fibroblasts.

Methods

Primary patient fibroblasts harbouring a homozygous G>A mutation (exon 42) or a heterozygous C>T mutation (exon 54) were gene edited using ABE8e mRNA, delivered via lipofectamine or six different LNPs. To assess the gene editing efficiency, Sanger sequencing and next-generation sequencing were employed. Cell viability was evaluated via a lactate dehydrogenase cytotoxicity assay, while functional restoration of C7 expression was assessed via Western blotting of cell lysate and supernatant. Finally, topical delivery was tested on normal human skin equivalents (HSEs).

Results

We identified an optimal ratio of 1 : 7 for sgRNA : ABE8e, at which editing efficiency increases with ABE8e dosage, with 400 ng being sufficient for 90% biallelic editing. Formulations containing DTDTMA (C14) and DHDTMA (C16) LNPs demonstrated approximately 90% and approximately 80% editing (with and without the peptide, respectively), in addition to reduced cytotoxicity compared with lipofectamine. Depending on the nature of the mutation, the edit corresponded to an increase in C7 expression in supernatant only or cell lysate as well, whereby C14 LNPs enabled twofold C7 restoration. Finally, our HSEs demonstrated viability of topical delivery of lipofectamine-encapsulated green fluorescent protein mRNA.

Conclusions

We demonstrated the potential value of base editing as a gene therapy for RDEB in addition to the potential of these LNPs for clinical translation of the therapy. Nonetheless, further safety and functionality tests still need to be conducted.
P09 Next-generation sequencing: on-and off-target analysis of gene editing in fibroblasts from patients with recessive dystrophic epidermolysis bullosa
Authors: Kazemizadeh Aidin , Brooks Imogen , Guri Ina , Alrokh Yara , Balon Katarzyna , Laczmanski Lukasz , McGrath John , Jackow-Malinowska Joanna
Published: May 2024

Introduction and aims

Base editors (BEs) and prime editors (PEs) have proved to have advantages over traditional clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 in correcting pathogenic mutations. We previously demonstrated 94.6% efficiency using adenine base editor (ABE)8e in correcting nonsense mutation (c.5047 C>T) in fibroblasts, which causes recessive dystrophic epidermolysis bullosa (RDEB). However, safety profile and cell-type-specific efficiencies of gene editing techniques have not been characterized. The aim of our research is to establish corrections of c.5047 C>T pathogenic variant in fibroblasts and compare off-target effects and efficiency of CRISPR-Cas9, BE and PE systems.

Methods

Primary fibroblasts harbouring heterozygous C>T pathogenic variant on exon 54 will be transfected with CRISPR-Cas9, ABE8e and PE using electroporation or lipofectamine. Both Sanger sequencing and next-generation sequencing (NGS) will be conducted to confirm pathogenic variant corrections. Galaxy platform which incorporates different NGS analysis tools will be used to analyse the NGS data. Subsequently, whole-exome sequencing and targeted amplicon sequencing will be used for off-target analysis.

Results

On-target efficiency for ABE8e to correct c.5047 C>T pathogenic variant in patient primary fibroblasts was determined first by Sanger sequencing showing 100% editing in contrast to 84% determined by NGS. Moving forward, we plan to correct the same pathogenic variant with PEs. Initially experiments are under way with PEmax mRNA and engineered PE guide RNAs (epegRNA) to compare different PEs. Furthermore, we will investigate the off-target effects of CRISPR-Cas9, ABE8e and PEs to edit RDEB primary fibroblasts using NGS Methods and conduct functional studies.

Conclusions

Here, we showed that the c.5047 C>T pathogenic variant in RDEB fibroblasts could be successfully edited using ABE8e. We demonstrated that NGS is required to precisely determine the editing efficacy. Taken together, we have established a pipeline for base editing in RDEB and we aim to achieve the same for prime editing in the future.
P15 Understanding the role of cathepsin H in atopic dermatitis pathogenesis
Authors: Tachie-Menson Theresa , Hughes Aaron , O’Toole Edel , O’Shaughnessy Ryan
Published: May 2024

Introduction and aims

Atopic dermatitis (AD) is a chronic skin condition ranked the 15th highest global burden for all nonfatal diseases. Our lab has found that patients with AD have a reduction in the gene and protein expression of cathepsin H, a lysosomal cysteine protease with aminopeptidase activity. Ctsh-/- mice have a reduced integrity of the epidermal barrier, including reduced filaggrin processing, reduced corneocyte integrity and a change in the expression of several proinflammatory mediators including interleukin-1α. We aim to elucidate the roles of cathepsin H in keratinocytes to understand its contribution to the pathogenesis of AD.

Methods

We utilized rat epidermal and N/TERT keratinocytes transiently overexpressing procathepsin B, H or L in addition to incubating keratinocytes with cathepsin H inhibitor (CTSHi) for 24 h to identify potential substrates and proteins upregulated or downregulated with cathepsin H expression. We also performed colocalization studies using indirect immunofluorescence in rat epidermal keratinocytes (REKs) and N/TERTs to investigate the biology of cathepsin H.

Results

REKs transiently overexpressing procathepsin H-FLAG or FLAG and REKs treated with the cathepsin H inhibitor H2N-Ser(OBzl)-CHN2 were analysed by liquid chromatography-mass spectrometry. This analysis indicated that keratin 1 and keratin 9 were upregulated with cathepsin H expression and downregulated by cathepsin H inhibition. Overexpressed procathepsin H and endogenous cathepsin H do not colocalize with the lysosomal membrane protein, LAMP1, whereas endogenous cathepsin B does.

Conclusions

Keratin 1 and keratin 9 could be coregulated with cathepsin H. Cathepsin H may not primarily localize to lysosomes unlike cathepsin B.
P16 Fibroblast signalling crosstalk drives junctional epidermolysis bullosa disease progression
Authors: Khan Mohammad R A , Kirk Thomas , Caley Matthew P , Rognoni Emanuel
Published: May 2024

Introduction and aims

Junctional epidermolysis bullosa (JEB) is a devastating hereditary skin disorder characterized by severe fragility of skin and mucus membrane, emerges as blistering with little or no trauma. The major classification of JEB includes JEB intermediate and JEB severe; the latter is the most common subtype, which is the result of loss of function mutations in the skin basement membrane protein laminin-332. Lacking this protein impairs basement membrane adhesion of epidermal keratinocytes and leads to deregulated epidermal–dermal crosstalk. The skin dermis is composed of multiple fibroblast subpopulations with different functions in skin homeostasis and repair; however, their specific involvement in skin diseases is largely unknown. Here, we investigate how fibroblast subpopulations, namely papillary and reticular fibroblasts, impact JEB disease progression and skin regeneration.

Methods

Three-dimensional (3D) organotypic (OT) combining healthy (control) and diseased (JEB) keratinocytes cells with distinct fibroblast subpopulations from different anatomical sites were developed and analysed by immunohistochemistry and RNA-Seq.

Results

JEB OTs with papillary fibroblasts showed increased epidermal growth, invagination of basal layer and deregulated differentiation compared with reticular fibroblasts. RNA-Seq analysis revealed altered activity in key signalling including immune, cytokine, gap junction, mitogen-activated protein kinase and remodelling of keratinization and ECM proteins, particularly in JEB OT cultured with papillary fibroblast. JEB OTs and cells also demonstrated variation in cell proliferation and activation of transforming growth factor-β1 and immune cell signalling. Currently, we are targeting identified signalling pathways in our two-dimensional and 3D cell culture models and identifying druggable targets, before testing selected candidates in our JEB mouse disease model for further preclinical validation.

Conclusions

By dissecting the pathological signalling interactions between keratinocytes and distinct fibroblast subpopulations, our goal is to identify new therapeutic target to improve the skin health and regeneration in patients with JEB.
Molecular Dynamics Simulation for the Acidic Compounds Retention Mechanism Study on Octyl-Quaternary Ammonium Mixed-Mode Stationary Phase
Authors: Chang Chaoqun , Jin Xinghua , Bai Hui , Zhang Fan , Chen Lei
Published: May 2024

With the widespread application of mixed-mode chromatography in separation analysis, it is becoming increasingly important to study its retention mechanism. The retention behavior of acidic compounds on mixed-mode octyl-quaternary ammonium (Sil-C8-QA) columns was investigated by computer simulation. Firstly, the benzoic acid homologues were used as the analytes, and the simulation model was constructed by the Materials Studio. Geometric optimization, annealing and molecular dynamics (MD) simulation of these complexes resulted in optimized conformations. The binding energy, mean square displacement (MSD) and torsion angle distribution generated by MD simulation were then analyzed. The results showed that the more negative binding energy, the greater the MSD and the narrower the torsion angle distribution, indicating that the stationary phase behaves with stronger interaction and retention. The retention behavior of five acidic drugs on the Sil-C8-QA column was then successfully explained by simulation. Acidic drugs are more retentive on the mixed-mode column due to the more substantial interaction brought by the reversed-phase/ion-exchange mixed-mode mechanism compared to other single-mode columns. This simulation method is expected to provide ideas for studying the separation mechanism and predicting the retention behavior of more complex samples.
Neutralising the ECT Sunset Clause Inter Se
Authors: Braoudakis Nikos , Craveia Rosanne , Baldon Clémentine
Published: May 2024

Following a wave of announcements from major EU Member States withdrawing or considering withdrawing from the Energy Charter Treaty (ECT), the European Commission decided to recommend a coordinated withdrawal of the EU and its Member States from the ECT. The European Commission also backs the adoption of a ‘subsequent agreement on the interpretation of the ECT’ between the EU and its Member States that would ‘clarify’ that the ECT and its sunset clause do not apply intra-EU. The sunset clause contained in Article 47(3) of the ECT has been described as a major hurdle in States’ attempt to exit the ECT. However, under an international treaty law analysis, strong arguments confirm the availability of an agreement between a subset of ECT Contracting Parties that would exclude the application of the ECT and its sunset clause in their relations inter se—including the envisaged EU agreement—as a suitable and effective alternative to modernisation of the ECT. Not only does this appear as the most desirable outcome in view of the continuing protection of fossil fuels under the modernised ECT, but such an agreement would also be firmly grounded in public international law.
Fast computational approach with prior dimension reduction for three-dimensional chemical component analysis using CT data of spectral imaging
Authors: Shiga Motoki , Ono Taisuke , Morishita Kenichi , Kuno Keiji , Moriguchi Nanase
Published: May 2024

Spectral image (SI) measurement techniques, such as X-ray absorption fine structure (XAFS) imaging and scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy (EDS) or electron energy loss spectroscopy (EELS), are useful for identifying chemical structures in composite materials. Machine-learning techniques have been developed for automatic analysis of SI data and their usefulness has been proven. Recently, an extended measurement technique combining SI with a computed tomography (CT) technique (CT-SI), such as CT-XAFS and STEM-EDS/EELS tomography, was developed to identify the three-dimensional (3D) structures of chemical components. CT-SI analysis can be conducted by combining CT reconstruction algorithms and chemical component analysis based on machine-learning techniques. However, this analysis incurs high-computational costs owing to the size of the CT-SI datasets. To address this problem, this study proposed a fast computational approach for 3D chemical component analysis in an unsupervised learning setting. The primary idea for reducing the computational cost involved compressing the CT-SI data prior to CT computation and performing 3D reconstruction and chemical component analysis on the compressed data. The proposed approach significantly reduced the computational cost without losing information about the 3D structure and chemical components. We experimentally evaluated the proposed approach using synthetic and real CT-XAFS data, which demonstrated that our approach achieved a significantly faster computational speed than the conventional approach while maintaining analysis performance. As the proposed procedure can be implemented with any CT algorithm, it is expected to accelerate 3D analyses with sparse regularized CT algorithms in noisy and sparse CT-SI datasets.
Incidence of Surgically Managed Post-Tonsillectomy Hemorrhage Associated With NSAID Prescribing for Postoperative Pain Management
Authors: Jacobson Andrew , Mack Douglas , Herrera Germaine , Bowe Sarah N , Highland Krista B , Patzkowski Michael S
Published: May 2024

Introduction

Tonsillectomy ranks high among the most common pediatric surgical procedures in the United States. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), such as ibuprofen, are routinely prescribed to manage post-tonsillectomy pain, but may carry the risk of hemorrhage.

Materials and Methods

This retrospective, longitudinal, secondary-data analysis study compared the incidence of surgically managed post-tonsillectomy hemorrhage (sPTH) in pediatric patients prescribed ibuprofen at Brooke Army Medical Center (BAMC) after tonsillectomy compared to a similar cohort of pediatric patients at the Children’s Hospital of Philadelphia (CHOP) not prescribed ibuprofen. Additional regression analysis examined predictors of sPTH at BAMC.

Results

The odds of sPTH was lower in patients who were prescribed ibuprofen at BAMC, relative to patients who were not at CHOP (OR 0.57, 95% CI, 0.37, 0.87; P < 0.01). In a generalized linear model evaluating BAMC patient data, there was a lack of a relationship between reason for tonsillectomy (tonsillitis versus tonsillar obstruction), primary procedure (tonsillectomy-only versus tonsillectomy with adenoidectomy), and presence of a co-occurring procedure.

Conclusions

Post-tonsillectomy ibuprofen prescribing practices were not associated with an elevated risk of sPTH, relative to patients at CHOP not exposed to ibuprofen.
The Role of Frequent Screening or Diagnostic Testing of Serum Cryptococcal Antigen in Liver Transplant Recipients: A Descriptive Epidemiology
Authors: Miwa Toshiki , Okamoto Koh , Ikeuchi Kazuhiko , Yamamoto Shinya , Okugawa Shu , Ichida Akihiko , Akamatsu Nobuhisa , Hasegawa Kiyoshi , Tsutsumi Takeya
Published: May 2024

Background

Cryptococcosis is a notable infectious complication of liver transplantation. Currently, there is no recommendation for screening serum cryptococcal antigen (CrAg) levels in solid organ transplant recipients. We aimed to explore the role of serum CrAg in liver transplant recipients at an institution where posttransplant serum CrAg has been widely tested.

Methods

This retrospective study was conducted at a tertiary care center in Japan. All liver transplant recipients with serum CrAg measured either for screening or for diagnostic testing at least once after transplantation between April 2005 and March 2022 were included. For participants with either a positive CrAg test result or positive culture for Cryptococcus, we manually reviewed clinical manifestations, management, and prognosis from the medical records.

Results

During the study period, 12 885 serum CrAg tests (median, 16 tests per patient) were performed in 468 liver transplant recipients. The 1-year posttransplant incidence of positive serum CrAg test results and culture-proven cryptococcosis was 1.9% (9/468) and 0.6% (3/468), respectively. No patient with persistently negative serum CrAg test results showed growth of Cryptococcus in culture. Four patients had clinical manifestations consistent with cryptococcosis, of whom 2 (50.0%) started antifungal therapy promptly based on a positive serum CrAg test result. In contrast, 5 patients had no clinical manifestations. Three of the 5 (60.0%) patients did not receive antifungal therapy and remained free of clinical manifestations.

Conclusions

Serum CrAg test was more sensitive than culture among liver transplant recipients and prompted early diagnosis and antifungal therapy in symptomatic patients. However, serial screening of serum CrAg in asymptomatic patients may be of little value, with the potential for false-positive results.