bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing particle string detection in electrorheological plasmas using asymmetrical kernel convolutional networks
Authors: Klein M , Dormagen N , Dietz C , Thoma M H , Schwarz M
Published: May 2024

Under different plasma conditions and electric fields in a complex plasma the plasma particles organize themselves in a string-like or chain-like manner. A phase transition from string-like to an isotropic particle distribution is observed at different electrical conditions. The streaming of charged ions around plasma particles with the surrounding electric field gives the plasma its electrorheological properties. The visibility of individual particles in a complex plasma opens up the opportunity to examine properties and phase transitions of such electrorheological fluids in detail. Because of the limited one-dimensional symmetry, determining the configuration of a particle and recognizing strings in particle distributions is not always straightforward. Several approaches have already been used to analyse particle clouds while either considering each particle locally or considering the particle cloud as a whole without providing information about single particle configurations. This paper presents a new machine learning approach that takes advantage of particle distributions over the entire particle cloud and detects all string-like particles at once, using a convolutional neural network in form of an encoder-decoder network with asymmetric kernel convolutions. This not only enhances the result quality but also accelerates the evaluation process, possibly enabling real-time analyses on electrorheological phase transitions, while achieving an accuracy of over 95% on manually labelled data.
Exploring the efficiency of green synthesized silver nanoparticles as photocatalysts for organic dye degradation: unveiling key insights
Authors: Sharma Aman , Sunny Sachin , Arulraj James , Hegde Gurumurthy
Published: May 2024

Silver nanoparticles (AgNPs) have received a lot of interest for their several applications, including their remarkable potential as photocatalysts for organic dye degradation. This research thoroughly investigates the efficacy of ecologically friendly, green-synthesized AgNPs in the treatment of synthetic dye-contaminated wastewater. The synthesis of AgNPs from various biological substrates is investigated, emphasizing their economic viability, significant conductivity, and considerable biocompatibility. The improper disposal of synthetic dyes in wastewater poses severe environmental and health risks due to their non-biodegradable nature and persistent chemical features. In response to this challenge, this review paper investigates the capability of AgNPs to serve as effective photocatalysts for degrading a range of organic dyes commonly found in industrial effluents. Specific dyes, including methyl orange, congo red, nitrophenol, methylene blue, and malachite green, are studied in the context of wastewater treatment, providing insights into the efficacy of AgNPs synthesized from diverse biological sources. The review sheds light on the photocatalytic degradation methods used by green-synthesized AgNPs, shedding light on the transition of these synthetic dyes into less hazardous compounds. It also delves into the toxicity aspect of the AgNPs and its possible remediation from the environment. The ecologically friendly synthesis procedures investigated in this work provide an alternative to traditional methods, highlighting the importance of sustainable technologies in solving modern environmental concerns. Furthermore, a comparative examination of various biological substrates for AgNPs synthesis is presented, evaluating their respective dye degradation efficiencies. This not only helps researchers understand the environmental impact of synthetic dyes, but it also directs them in choosing the best substrates for the production of AgNPs with enhanced photocatalytic activities.
Quotient singularities in the Grothendieck ring of varieties
Authors: Esser Louis , Scavia Federico
Published: May 2024

Let

G
G

be a finite group,

X
X

be a smooth complex projective variety with a faithful

G
G

-action, and

Y
Y

be a resolution of singularities of

X

/

G

X/G

. Larsen and Lunts asked whether

[
X

/

G
]
−
[
Y
]

[X/G]-[Y]

is divisible by

[

A

1

]

[\mathbb {A}^1]

in the Grothendieck ring of varieties. We show that the answer is negative if

B
G

BG

is not stably rational and affirmative if

G
G

is abelian. The case when

X
=

Z
n

X=Z^n

for some smooth projective variety

Z
Z

and

G
=

S
n

G=S_n

acts by permutation of the factors is of particular interest. We make progress on it by showing that

[

Z
n

/

S
n

]
−
[
Z
⟨
n
⟩

/

S
n

]

[Z^n/S_n]-[Z\langle n\rangle / S_n]

is divisible by

[

A

1

]

[\mathbb {A}^1]

, where

Z
⟨
n
⟩

Z\langle n\rangle

is Ulyanov’s polydiagonal compactification of the

n
n

th configuration space of

Z
Z

.
Tubulin glycylation controls ciliary motility through modulation of outer-arm dyneins
Authors: Kubo Tomohiro , Sasaki Rinka , Oda Toshiyuki
Published: May 2024

Tubulins undergo several kinds of posttranslational modifications (PTMs) including glutamylation and glycylation. The contribution of these PTMs to the motilities of cilia and flagella is still unclear. Here, we investigated the role of tubulin glycylation by examining a novel Chlamydomonas mutant lacking TTLL3, an enzyme responsible for initiating glycylation. Immunostaining of cells and flagella revealed that glycylation is only restricted to the axonemal tubulin composing the outer-doublet but not the central-pair microtubules. Furthermore, the flagellar localization of TTLL3 was found to be dependent on intraflagellar transport. The mutant, ttll3(ex5), completely lacks glycylation and consequently exhibits slower swimming velocity compared with the wild-type strain. By combining the ttll3(ex5) mutation with multiple axonemal dynein-deficient mutants, we found that the lack of glycylation does not affect the motility of the outer-arm dynein lacking mutations. Sliding disintegration assay using isolated axonemes revealed that the lack of glycylation decreases microtubule sliding velocity in the normal axoneme but not in the axoneme lacking the outerarm dyneins. Based on our recent study that glycylation occurs exclusively on β-tubulin in Chlamydomonas, these findings suggest that tubulin glycylation controls flagellar motility through modulating outer-arm dyneins, presumably by neutralizing the negative charges of glutamate residues at the C-terminus region of β-tubulin.
Norms Governing Rescue and Return
Authors: Variath Adithya
Published: May 2024

The issues of rescue and return have grown in parallel with the development of space exploration activities. The launch of Sputnik in 1957 also exposed the difficulties in relation to the return of such satellites to foreign soil. State practice mandates that a spacecraft which lands on foreign soil remain the property of the launching state and should be returned upon payment of compensation for any damages caused by such landing. As a response to this, on 19 December 1967, the General Assembly of the United Nations, by a vote of 115–0, approved the Agreement on the Rescue of Astronauts, the Return of Astronauts and the Return of Objects Launched into Outer Space 1968 (hereinafter the Rescue Agreement). This chapter, along with deconstructing the Rescue Agreement, also analyses the essential substantive clauses of the Rescue Agreement, namely ‘Personnel of a spacecraft’ and ‘Space objects and their launching authorities’. The chapter will also highlight the issues that arise due to launching from non-sovereign territory, such as the high seas, which complicate the question of ‘launching authority’. The second section of the chapter focuses on the two underlying Articles V and VIII of the Outer Space Treaty dealing with the status of astronauts and the ownership of space objects by the launching state. The third section studies the issues relating to the interpretation of private and public spaceflight in the Rescue Agreement.
Third World Approaches to International Space Law
Authors: Vazhapully Kiran Mohan
Published: May 2024

This chapter provides a critical examination of international space law through the lens of Third World Approaches to International Law (TWAIL). It traces the origins of space law to the Cold War era, highlighting how it was shaped by the interests of technologically advanced States, particularly the United States and the Soviet Union. The chapter relies on TWAIL perspectives to scrutinise this dominance, revealing the Eurocentric biases and power dynamics embedded within the legal system. It argues that while the principles of space law, such as non-appropriation and peaceful use, appear universal, they are underpinned by biases favouring Western States. The chapter also explores the historical context of TWAIL, its theoretical underpinnings, and its role in challenging global disparities. It proposes reforms to international space law, emphasising the need for a more equitable legal framework that truly encompasses the interests of all States, including those in the Global South. It calls for a collective endeavour to deconstruct and reconstruct law to address historical imbalances and benefit all of humanity, offering a universal vision of international law and justice.
Women in Martial
Authors: Marchesi Ilaria
Published: May 2024

Martial’s Women is the first monograph to treat the portrayals of women in the Epigrams in a systematic way. Presenting an interplay between the close reading of a wide range of poems and their contextualization through legal, historiographic, rhetorical, and grammatical discussions, this book proposes a new way of conceptualizing the cultural construction of femininity in the Flavian age. The book focuses not only on the social roles assigned to women in Roman society, where they are at once called to represent their fathers and reproduce their husbands, but also on the question to what extent they are depicted as semiotic signifiers in Martial’s corpus, a poet who distinctively adopts the role of a surrogate censor for Domitian. Noting socially aberrant behavior by pointedly using the discourse of grammar and its categories to detect and address the social issues of his time, Martial constructs the women he depicts in both negative and positive ways as signs of their time.
Conclusion
Authors: Marchesi Ilaria
Published: May 2024

The conclusion reads the attention that Pliny’s Panegyricus devotes to the mechanics of Trajan’s adoption, association, and accession to power in light of the socio-political and ethical anxieties detected in Martial around women’s semiotic power. In praising Nerva’s decision to adopt his successor from outside the familial sphere, Pliny also constructs as abnormal and undue the traditional influence that imperial women exerted on imperial successions. Pliny’s systemic discounting of the past as specifically encumbered by powerful women translates into a generative, not simply generational anxiety, which connects his hallowed renovatio with a systemic repression of the woman’s body.
Structural diversity of decalin forming Diels–Alderase
Authors: Sato Michio
Published: May 2024

The Diels–Alder (DA) reaction, specifically referring to the [4 + 2] cycloaddition reaction in pericyclic reactions, is a process that forms two carbon-carbon covalent bonds in a single step via an electron ring transition state. Among the secondary metabolites produced by microorganisms, numerous compounds are biosynthesized through DA reactions, most of which are enzymatic. Our research group has discovered an enzyme named Diels–Alderase (DAase) that catalyzes the DA reaction in filamentous fungi, and we have been investigating its catalytic mechanism. This review describes the reported microbial DAase enzymes, with a particular focus on those involved in the construction of the decalin ring.
Sex allocation is color morph-specific and associated with fledging condition in a wild bird
Authors: Tooth Amandine , Morosinotto Chiara , Karell Patrik
Published: May 2024

Melanin-based color polymorphism is predicted to evolve and maintain through differential fitness of morphs in different environments, and several empirical studies indicate that life history strategies, physiology, and behavior vary among color morphs. Sex allocation theory predicts that parents should adjust their sex allocation based on differential costs of raising sons and daughters, and therefore, color morphs are expected to modify their brood sex ratio decisions. In color polymorphic tawny owls (Strix aluco), the pheomelanistic brown morph is associated with higher energy requirements, faster growth, and higher parental effort than the gray morph. As hypothesized, we find that brown tawny owl mothers produced more daughters in early broods and more males in late broods, whereas gray mothers did the opposite. At fledging, daughters of early broods and of brown mothers were heavier than those of late broods or gray mothers. Hence, larger and more costly daughters appeared to benefit more than males from being born to brown mothers early in the season. Brown mothers breeding later in the season produced more cheap sons, while gray mothers face fewer challenges under limited resources and favor daughters. These findings suggest that environmental conditions influence brood sex allocation strategies of genetically determined color morphs differently.
High-throughput surface epitope immunoaffinity isolation of extracellular vesicles and downstream analysis
Authors: Khanabdali Ramin , Mandrekar Michelle , Grygiel Rick , Vo Phuoc-An , Palma Carlos , Nikseresht Sara , Barton Siena , Shojaee Mozhgan , Bhuiyan Sadman , Asari Kartini , Belzer Susan , Ansari Khairul , Coward Jermaine I , Perrin Lewis , Hooper John , Guanzon Dominic , Lai Andrew , Salomon Carlos , Kershner Kevin , Newton Christine , Horejsh Douglas , Rice Gregory
Published: May 2024

Extracellular vesicles (EVs), including exosomes, have significant potential for diagnostic and therapeutic applications. The lack of standardized methods for efficient and high-throughput isolation and analysis of EVs, however, has limited their widespread use in clinical practice. Surface epitope immunoaffinity (SEI) isolation utilizes affinity ligands, including antibodies, aptamers, or lectins, that target specific surface proteins present on EVs. Paramagnetic bead-SEI isolation represents a fit-for-purpose solution for the reproducible, high-throughput isolation of EVs from biofluids and downstream analysis of RNA, protein, and lipid biomarkers that is compatible with clinical laboratory workflows. This study evaluates a new SEI isolation method for enriching subpopulations of EVs. EVs were isolated from human plasma using a bead-based SEI method designed for on-bead and downstream analysis of EV-associated RNA and protein biomarkers. Western blot analysis confirmed the presence of EV markers in the captured nanoparticles. Mass spectrometry analysis of the SEI lysate identified over 1500 proteins, with the top 100 including known EV-associated proteins. microRNA (miRNA) sequencing followed by RT-qPCR analysis identified EV-associated miRNA transcripts. Using SEI, EVs were isolated using automated high-throughput particle moving instruments, demonstrating equal or higher protein and miRNA yield and recovery compared to manual processing. SEI is a rapid, efficient, and high-throughput method for isolating enriched populations of EVs; effectively reducing contamination and enabling the isolation of a specific subpopulation of EVs. In this study, high-throughput EV isolation and RNA extraction have been successfully implemented. This technology holds great promise for advancing the field of EV research and facilitating their application for biomarker discovery and clinical research.
Isolation of short RNAs with homogeneous 3′-ends using quaternary-amine anion exchange chromatography
Authors: Li Zixian , Bilic Mia , Nagar Bhushan
Published: May 2024

Visualizing RNA–protein interactions through structural approaches requires the use of RNA molecules purified to homogeneity. We describe here a simple and effective method, free of acrylamide contamination and without using UV radiation, to separate in vitro synthesized, heterogeneous RNA transcripts (up to ∼15 nucleotides) at single-nucleotide resolution by quaternary-amine anion exchange chromatography. The quality of short RNAs isolated through this method is validated by gel electrophoresis, mass spectrometry, and crystallization with a protein-binding partner.
O22 Unravelling the pathophysiology of KLICK syndrome to identify therapeutically targetable pathways
Authors: Cherry Hannah , Rastrick Joe , Jacków Joanna , Parsons Maddy , McGrath John
Published: May 2024

Introduction and aims

Keratosis linearis with ichthyosis congenita and sclerosing keratoderma (KLICK) syndrome is an ultrarare genodermatosis associated with a homozygous pathogenic variant, c.-95delC in POMP, which encodes for proteasome maturation protein. Clinical manifestations include linear hyperkeratotic papules in the flexures, palmoplantar keratoderma and pseudoainhum. The pathophysiology of KLICK syndrome is poorly understood, resulting in nonspecific, limited treatment options. The aim of this work is to characterize KLICK syndrome at the cellular and molecular level, with the utilization of transcriptomic techniques for potential drug repurposing.

Methods

A lesional skin biopsy was obtained, following informed consent, from a 32-year-old female patient with KLICK syndrome. Histology and immunostaining were used to characterize the disrupted skin architecture. RNA sequencing was used to identify key dysregulated pathways and the L1000FWD reverse transcriptomics tool enabled the generation of a shortlist of potential therapeutics for KLICK syndrome. CRISPR editing techniques and induced pluripotent stem cell (iPSC) reprogramming Methods were used to generate cellular based models carrying the pathogenic POMP variant in order to support evaluation of the shortlisted therapeutic options.

Results

KLICK syndrome skin histology featured hyperkeratosis, hypergranulosis and delayed cellular flattening. Consistent with pathological features, pathway analysis of transcriptomic data revealed keratinocyte differentiation and epidermis development as key upregulated pathways in KLICK syndrome. Interestingly, the Panther pathway analysis tool suggested dysregulation in epidermal growth factor receptor (EGFR) signalling, and reverse transcriptomics identified erlotinib, an EGFR inhibitor, as a potential therapeutic treatment for KLICK syndrome. HaCaT keratinocytes were successfully edited using CRISPR-Cas9 to carry the KLICK patient POMP variant and a KLICK patient iPSC line was generated to support in vitro KLICK syndrome modelling.

Conclusions

KLICK syndrome is a hyperproliferative inflammatory skin disorder associated with a pathogenic variant in POMP. Reverse transcriptomics is a useful tool for shortlisting drugs with biologically relevant mechanisms of action with potential for treatment of rare genetic diseases such as KLICK syndrome.
P01 Remodelling of the dermoepidermal junction occurs in intrinsically aged Far East Asian skin without significant epidermal atrophy
Authors: Lim Zoe , Lunny Declan , Bonnard Carine , Langton Abigail , Watson Rachel
Published: May 2024

Introduction and aims

Ageing is characterized by a gradual decline in physiological function and is influenced by both intrinsic genetic and extrinsic lifestyle and environmental factors. However, much of our knowledge of cutaneous ageing comes from the study of White populations. We have previously shown that the organization of young healthy skin is ethnicity-dependent and that altered epidermal morphology in White volunteers correlates with loss of biomechanical function in the skin. In this study, we used epidermal morphometry to determine whether parameters associated with intrinsic skin ageing in White skin are also observed in Far East Asian skin.

Methods

Archival skin samples were obtained from the Asian Skin Biobank [young (3–21 years), N = 38, 37 male samples (Chinese, n = 16; Malay, n = 16; other Far East, n = 6); aged (61–86 years), N = 7, one male sample (Chinese, n = 6; Malay, n = 1)] and stained with haematoxylin and eosin prior to image analysis for dermoepidermal junction (DEJ) convolution and measurement of epidermal thickness. Weigert’s resorcin-fuchsin stain was used to ensure samples were photoprotected.

Results

Weigert’s resorcin-fuchsin stain revealed that all samples were photoprotected, with no evidence of solar elastosis. We next compared whether geographic ancestry of our local Far East Asian population impacted epidermal morphology in young skin; neither DEJ convolution nor epidermal thickness were impacted by geographic ancestry. However, a significant flattening of the DEJ was observed between young and aged samples (P < 0.01). Interestingly, no significant difference in epidermal thickness was observed as a function of age.

Conclusions

While intrinsically aged Asian skin undergoes the same flattening of the DEJ that is seen in White populations, epidermal thickness does not significantly alter; this is in stark contrast to intrinsically aged White skin, where epidermal atrophy is observed. Hence, the trajectory of intrinsic cutaneous ageing may be ethnicity-dependent, providing further evidence that studies of skin from different ethnicities are necessary.
P02 Accelerated ageing of hair follicles in androgenetic alopecia
Authors: Limbu Summik , Farhat Kim , Redmond Leah , Farjo Nilofer , Farjo Bessam , Kemp Paul , Higgins Claire
Published: May 2024

Introduction and aims

Androgenetic alopecia (AGA) is defined by hair loss from the frontal, parietal and vertex regions of the scalp; however, occipital follicles are spared. Hair follicles in AGA undergo miniaturization, which is the transition of terminal follicles into vellus follicles. Similarly with age, the diameter of the hair shaft decreases with loss of pigmentation, which is also seen in miniaturized follicles. To investigate whether frontal follicles have accelerated ageing compared with occipital follicles, we looked at methylation levels of genes associated with ageing. As the thickness and pigmentation of hair fibre are influenced by the dermal papilla (DP), we conducted microarray analysis of frontal and occipital DP to establish whether accelerated ageing of follicles is driven by DP.

Methods

The biological age of frontal and occipital follicles was calculated using methylation status of ELOVL2, ASPA, EDARADD and PDE4C (n = 3). For microarray analysis, DP was microdissected from the frontal (FDP) and occipital (ODP) follicles from patients undergoing hair transplantation surgeries to treat AGA (n = 4).

Results

Frontal follicles were found to have significantly higher biological age compared with patient-matched occipital follicles suggesting accelerated ageing of follicles in AGA. Transcriptomic analysis revealed significant increase in expression of several genes in FDP and notably EGR1, HSPB1, DNAJB1 and APOD, which have been shown to be upregulated in the DP of aged mice compared with young mice. We found downregulation of TRPS1 in FDP, which represses EGR1. Mutations in TRPS1 underlie trichorhinophalangeal syndrome which is associated with vellus-type hair.

Conclusions

Our transcriptional and molecular analysis revealed that FDP and frontal follicles have an advanced biological age relative to ODP. This increased age is also reflected in the transcriptional signature of FDP. We hypothesize that these changes are in part due to regulation of signalling by the transcriptional repressor TRPS1, whose expression is decreased in FDP.
P07 Mutagenicity of narrowband ultraviolet B
Authors: Fowler Joanna , Coltart George , Sood Roshan , Lai Chester , Nadarajah Noeline , Jones Philip , Healy Eugene
Published: May 2024

Introduction and aims

Exposure to ultraviolet (UV) radiation causes DNA mutations in skin and development of skin cancer. Despite this, UV radiation in the form of narrowband UVB is commonly used by dermatologists to treat skin diseases such as psoriasis. However, the mutagenicity of narrowband UVB in human skin is unknown. In this study, we investigated the mutation burden resulting from a course of narrowband UVB in patients with psoriasis.

Methods

Skin biopsies were taken from uninvolved skin of sixteen patients with psoriasis before and after a treatment course of narrowband UVB. Following microdissection, DNA was extracted from the epidermis and sequenced using nanorate sequencing (NanoSeq), which detects mutations in single molecules of DNA with an error rate of fewer than five errors per billion base pairs. Whole-genome sequencing of blood DNA was employed as germline control. Comparison of mutations in prenarrowband UVB and postnarrowband UVB skin samples allowed quantification of mutation burden and mutational signatures owing to narrowband UVB.

Results

There was a significant increase in the mutation burden in skin following the narrowband UVB treatment course, with UV radiation signatures SBS7a, SBS7b and DBS1 documented in both nonsun-exposed skin and frequently sun-exposed skin samples. Comparison of the magnitude of the mutation burden resulting from narrowband UVB to that in keratinocyte cancers provided insight into the mutagenicity of narrowband UVB in relation to the potential numbers of narrowband UVB courses over a lifetime that might lead to skin cancer development.

Conclusions

Narrowband UVB treatment for psoriasis Results in significant numbers of UV-radiation-induced mutations in human skin.
P14 Characterizing the hair follicle–nervous system connection
Authors: Rhodes Anna , Agramunt Julià , Limbu Summik , Laufer Rimma , Jiménez Francisco , Williams Greg , Knight Leigh , Hashemi Parastoo , Higgins Claire
Published: May 2024

Introduction and aims

The human hair follicle (HF) is a miniorgan in the skin that possesses a rich microenvironment composed of a complex assembly of sensory nerves that surround it. Recent studies have explored the effects of this perineural niche on the HF, but the influence of HF on the nervous system from a folliculocentric and skin-centric perspective remains underexplored. To explore the potential bidirectionality of the HF–nervous system connection in the context of nerve development, we asked whether the HF influences the differentiation and maturation of sensory neuron subtypes around it through the release of distinct neurotransmitters and neurotrophic factors.

Methods

To first identify which cell types might be involved in directing sensory neuron development, we reanalysed available skin and HF single-cell RNA sequencing (scRNA-Seq) datasets. Next, to evaluate neurotransmitter release from these cell types, we used fast-scan cyclic voltammetry (FSCV). Lastly, to interrogate the role of the HF on directing neuronal development in vitro, we used induced pluripotent stem cell-derived sensory neurons as a model for developing nerves.

Results

We found that a higher percentage of KRT14- (epithelial) and PDGFRA-expressing (mesenchymal) cells in the HF coexpressed genes encoding specific neurotrophic factors and enzymatic machinery for neurotransmitter production compared with equivalent cells in the skin, suggesting that the HF possesses a greater capacity to signal to the nervous system compared with interfollicular skin. Using FSCV, we then found that follicular outer root sheath and directionally selective cells are capable of releasing neurotransmitters such as serotonin and histamine.

Conclusions

We postulate that HF-derived neurotransmitters are important for aspects of sensory neuron development such as axonal growth, as serotonin has previously been shown to be an attractive guidance cue for neuronal growth cones. Overall, our work sheds light on the HF–nervous system connection and how the HF may regulate its microenvironment in the skin.
P17 Dissection of the molecular and cellular heterogeneity of dermal fibroblasts in skin fibrosis
Authors: Ahmed Abubkr , Kirk Thomas , O’Toole Edel , Rognoni Emanuel
Published: May 2024

Introduction and aims

Skin fibrosis, a common fibrotic condition that currently has no specific treatments or cures, is caused by persistent activation of skin fibroblasts after tissue injury that Results in excessive scarring, can cause severe disability and seriously affect morbidity. This study aims to uncover the specific fibroblast subsets and molecular pathways that are integral to this sustained fibroblast activation using a bleomycin-induced skin fibrosis mouse model that accurately recapitulates the human disease.

Methods

We have successfully shown that 2 weeks (early) and 4 weeks (advanced) of bleomycin injections Results in an increasing severity of skin fibrosis characteristics. Following this treatment, we performed single-cell RNA sequencing (scRNA-Seq) using control, early and advanced fibrotic tissue and identified fibroblast subclusters and specific gene signatures that are altered across the time course and may play a role in the fibrotic phenotype we observe. The use of advanced scRNA-Seq analysis techniques such as SCENIC and regulon analysis has allowed us to further characterize the changes in fibroblast states during fibrosis.

Results

Our scRNA-Seq data show a loss of fibroblast heterogeneity alongside the emergence of two main subclusters with distinct gene signatures in the advanced fibrotic state. While proliferation is minimal, RNA velocity analysis indicates that the increase in cell count is due to the convergence of neighbouring fibroblast subclusters. The pronounced profibrotic gene expression point to its key role in driving skin fibrosis and we are now exploring the therapeutic potential of chemically or genetically targeting this subcluster.

Conclusions

Our novel skin fibrosis time course scRNA-Seq dataset allows us to compare the cellular and molecular changes in early and advanced fibrotic lesions in order to identify the key fibroblast subpopulations, molecular regulators and connective tissue alterations promoting fibrotic tissue repair. Our findings will support the development of new fibroblast-targeted fibrosis therapies in skin and potentially in other organs.
P29 Long-read sequencing provides unprecedented insight into the skin and wound microbial landscape
Authors: Smythe Paisleigh , Wilkinson Holly
Published: May 2024

Introduction and aims

It is becoming increasingly evident that the microbial inhabitants of our skin play a key role in cutaneous health and disease. However, our understanding of the contribution of the complex skin microbiome to wound healing outcome remains incomplete. This is, in part, due to the historic challenges around traditional sampling and profiling Methods, which often fail to capture the abundance and diversity of the skin microbiome. Recent advances in microbiome sequencing technologies now enable more comprehensive characterization of skin bacterial composition and host-microbe interactions. Thus, the aim of this study was to utilize a novel long-read sequencing platform to provide species-level microbiome characterization and deliver important insight into the drivers of pathological skin repair.

Methods

Microbial DNA samples were collected from the skin and wounds of healthy volunteers and patients with chronic wounds (n = 40 per group). Long-read nanopore sequencing was used to profile microbiome samples, while RNA-Seq enabled generation of donor transcriptomic profiles. A multifaceted approach was used to integrate these datasets to investigate the complex interplay between host skin pathology and the microbiome.

Results

We first identified perturbations in the skin microbiome of patients with chronic wounds, which was significantly less diverse than healthy skin and colonized with key bacteria associated with pathogenicity. These alterations in the skin microbiome also correlated with transcriptomic changes, such as upregulation of genes associated with inflammation, stress and poor healing. Interestingly, long-read sequencing data displayed poor correlation with routine clinical microbiology swabs, while specific clinical characteristics (e.g. glycaemic control and wound duration) were strongly linked to wound microbiome composition.

Conclusions

Collectively, these data provide crucial new insight into the skin and wound microbial landscape, demonstrating a potential role for specific wound bacteria in modulating pathological skin repair.
P30 Exposure to particulate matter induces structural and pigmentary changes to human skin
Authors: Deyvapriya S , Halai Poonam , Kiss Orsolya , Mambwe Bezaleel , Watson Rachel , Langton Abigail
Published: May 2024

Introduction and aims

The majority of the world’s population reside in places with high levels of air pollution. The impact of air pollution on human health has been extensively studied and demonstrates a significant correlation between particulate matter (PM) and risk of cardiovascular and respiratory diseases. However, little is known about the impact of air pollution on human skin health. Here, we develop an ex vivo skin model to investigate cutaneous changes induced by the topical application of PM.

Methods

PM (0, 0.5, 3, 6, 10, 20 and 40 μg mL−1) was topically applied to Genoskin® NativeSkin Access® (Genoskin, Salem, MA, USA) human ex vivo skin samples of White European ancestry (n = 3) for 8 days, with reapplication on day 4. Resultant samples were assessed using haematoxylin and eosin staining (for morphometric analyses), immunofluorescence for Ki67 and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) (to determine cellular turnover), while pigmentary changes were analysed by colourimetry, Warthin–Starry (WS) staining and immunohistochemistry for the melanin markers tyrosinase (TYR), gp100 and c-kit.

Results

Morphological assessment revealed that epidermal thickness was significantly reduced following exposure to higher doses of PM (r = −0.9163, P < 0.01). In addition, there was reduced epidermal cell proliferation (Ki67) and increased apoptosis (TUNEL) at higher doses of PM. Exposure to PM resulted in a dose-dependent decrease in individual typology angle, which is indicative of skin colour becoming darker (r = −0.7895, P < 0.05). Furthermore, WS staining demonstrated significantly increased epidermal melanin (r = 0.9583, P < 0.01) and significantly increased expression of melanin markers TYR (P < 0.01), gp100 (P < 0.001) and c-kit (P < 0.01) in response to PM exposure.

Conclusions

This study confirms that PM induces pigmentary changes to ex vivo human skin by increasing epidermal melanin. Increased expression of c-kit in response to PM exposure suggests that increased pigmentation occurs owing to the upregulation of the microphthalmia-associated transcription factor signalling pathway. Further investigation of the mechanistic drivers of increased pigmentation is warranted.
P32 Melanin confers protection against ultraviolet radiation-mediated mitochondrial DNA damage in skin of colour
Authors: Mambwe Bezaleel , Langton Abigail
Published: May 2024

Introduction and aims

Melanin is a photoprotective pigment that effectively absorbs and scatters solar ultraviolet radiation (UVR) affording protection against nuclear DNA photodamage. In lightly pigmented skin, UVR-mediated damage of cellular DNA is not limited to nuclear DNA; mitochondrial DNA (mtDNA) is also susceptible to UVR-induced damage leading to an increased frequency of deletions and mutations. However, the protective role of melanin against UVR-induced mtDNA damage is unknown. Therefore, we sought to determine whether melanin affords protection against UVR-induced mtDNA damage.

Methods

Using Genome Analysis Toolkit best practices, mtDNA was extracted from photoexposed forearm and photoprotected buttock of Black African (n = 3) and White Northern European (n = 3) volunteers and sequenced to identify somatic mutations.

Results

Comparison of photoexposed forearm with photoprotected buttock identified a total of 21 somatic mutations, including single-nucleotide transitions, deletions and additions. Of these, three somatic mutations were observed in Black skin, whereas 18 were identified in White skin (P < 0.01). Analysis of single-nucleotide transitions revealed a total of 13 variations and of these, two were identified in Black skin and 11 in White skin. Interestingly, of the somatic mutations observed in White skin, there was enrichment of the cytosine to thymine (C>T) transitions in all volunteers. In contrast, photoexposed Black skin had a thymine to guanine transition at position 414 (T414G) identified for two of the three Black volunteers.

Conclusions

Here we identified that Black skin exhibited fewer mtDNA mutations compared with White skin; enrichment of C>T transitions in White skin is consistent with a previously reported UVR-signature of mtDNA damage, whereas the T414G transition identified in Black photoexposed skin has previously been suggested as a mitochondrial biomarker of photoageing. Our study suggests that melanin confers protection against UVR-mediated mtDNA damage and that the mtDNA damage signature differs between skin types.
Capsaicin enhances cisplatin-induced anti-metastasis of nasopharyngeal carcinoma by inhibiting EMT and ERK signaling via serpin family B member 2
Authors: Xu Yafei , Kong Weimiao , Zhao Simin , Xiong Dan , Wang Yejun
Published: May 2024

Cisplatin (DDP)-based combined chemotherapy or concurrent chemoradiotherapy is the mainstay treatment for advanced-stage nasopharyngeal carcinoma (NPC), but needs improvement due to its severe side effects. Capsaicin (CAP) can enhance the anti-tumor activity of cytotoxic drugs. The aim of this study was to investigate the anti-metastasis activity of CAP in combination with DDP in NPC. Herein, CAP and DDP showed synergistic cytotoxic effects on NPC cells. CAP alone and DDP alone inhibited NPC migration and invasion in vitro and in vivo, and the combination of CAP and DDP had the greatest effect. Moreover, CAP upregulated the mRNA and protein expressions of serpin family B member 2 (SERPINB2). Further results showed that both SERPINB2 mRNA and protein expressions were downregulated in NPC cell lines and tissues and SERPINB2 overexpression inhibited NPC migration and invasion in vitro and in vivo, while silencing SERPINB2 acted oppositely. In addition, SERPINB2 was abnormally expressed in head and neck squamous cell carcinoma and other multiple cancers, and downregulation of SERPINB2 predicted poor prognosis in head and neck squamous cell carcinoma according to the Cancer Genome Atlas database. We further found that SERPINB2 overexpression inhibited epithelial–mesenchymal transition (EMT) and the phosphorylated extracellular signal-regulated kinase (p-ERK), and the inhibitory effect was enhanced by CAP and DDP. Altogether, our results suggest that the combined inhibition of CAP and DDP on NPC metastasis may be related to the inhibition of epithelial–mesenchymal transition and ERK signals mediated by SERPINB2, and CAP may help to improve the efficacy of DDP in the treatment of NPC and develop new therapeutic approaches.
Rapid and Sensitive Detection of Fentanyl and Its Analogs by a Novel Chemiluminescence Immunoassay
Authors: Zhao Jiang-yang , Uddin Mezbah , Unsihuay Daisy , Butler William , Xia Terrance W , Xu Jayson Z , Wang Simon , Sheng Xiaolin , Jannetto Paul J , Wang Ping , Xia Xiaofeng
Published: May 2024

Background

Abuse of fentanyl and its analogs is a major contributor to the opioid overdose epidemic in the United States, but detecting and quantifying trace amounts of such drugs remains a challenge without resorting to sophisticated mass spectrometry-based methods.

Methods

A sensitive immunoassay with a sub-picogram limit of detection for fentanyl and a wide range of fentanyl analogs has been developed, using a novel high-affinity antibody fused with NanoLuc, a small-size luciferase that can emit strong and stable luminescence. When used with human urine samples, the assay has a sub-picogram limit of detection for fentanyl, with results fully concordant with LC-MS.

Results

When applied to clinical samples, the novel chemiluminescence immunoassay can detect low positive fentanyl missed by routine screening immunoassays, with a limit of detection of 0.8 pg/mL in human urine. When applied to environmental samples, the assay can detect levels as low as 0.25 pg fentanyl per inch2 of environment surface. Assay turnaround time is less than 1 h, with inexpensive equipment and the potential for high-throughput automation or in-field screening.

Conclusions

We have established a novel assay that may have broad applications in clinical, environmental, occupational, and forensic scenarios for detection of trace amounts of fentanyl and its analogs.
Incidence and factors associated with PrEP discontinuation in France
Authors: Garofoli Nina , Siguier Martin , Robineau Olivier , Valette Michel , Phung Bao , Bachelard Antoine , Rioux Christophe , Le Gac Sylvie , Digumber Marc , Pialoux Gilles , Ghosn Jade , Champenois Karen
Published: May 2024

Objectives

HIV pre-exposure prophylaxis (PrEP) is effective in preventing HIV, but some seroconversions occur due to poor adherence or PrEP discontinuation. Our objective was to estimate the incidence of PrEP discontinuation and describe the reasons and factors associated with discontinuations.

Methods

A retrospective cohort was conducted in three French hospitals between January 2016 and June 2022. PrEP users who attended at least twice within 6 months during study period were included and followed up until December 2022. The incidence rate of PrEP discontinuation was estimated by censoring lost to follow up individuals. Factors associated with PrEP discontinuations were identified using a multivariate Cox model.

Results

A total of 2785 PrEP users were included, with 94% men and 5% transgender people. Median age was 35 years. By December 2022, 653 users had stopped PrEP (24%). The incidence rate was 10.8 PrEP discontinuations for 100 person-years (PY). The main causes of discontinuation were being in a stable relationship (32%), and not judging the treatment useful anymore (12%). Individuals who discontinued PrEP were younger [<29, HR = 1.45 (1.17–1.80)], and more likely to be women [HR = 2.44 (1.50–3.96)] or sex workers [HR = 1.53 (0.96–2.44)]. They were more likely to report PrEP side effects [HR = 2.25 (1.83–2.77)] or ≥2 sexually transmitted infections [HR = 1.87 (1.53–2.27)] during the last year.

Conclusion

The incidence of PrEP discontinuations was quite low compared to rates observed in other cohorts. Users who stopped PrEP were sometimes still exposed to HIV, emphasizing the need for targeted interventions to prepare and support PrEP discontinuations and limit seroconversion risk.
Knowledge, awareness and practices of healthcare workers regarding antimicrobial use, resistance and stewardship in Zambia: a multi-facility cross-sectional study
Authors: Mudenda Steward , Chabalenge Billy , Daka Victor , Jere Elimas , Sefah Israel Abebrese , Wesangula Evelyn , Yamba Kaunda , Nyamupachitu Julian , Mugenyi Nathan , Mustafa Zia Ul , Mpundu Mirfin , Chizimu Joseph , Chilengi Roma
Published: May 2024

Background

Antimicrobial resistance (AMR) poses a threat to public health globally. Despite its consequences, there is little information about the knowledge, awareness, and practices towards AMR among healthcare workers (HCWs). Therefore, this study assessed the knowledge, awareness and practices regarding antimicrobial use (AMU), AMR and antimicrobial stewardship (AMS) among HCWs who are involved in the implementation of AMS activities across eight hospitals in Zambia.

Methods

A cross-sectional study was conducted among 64 HCWs from October to December 2023 using a semi-structured questionnaire. Data were analysed using IBM SPSS version 25.0.

Results

Of the 64 HCWs, 59.4% were females, 60.9% were aged between 25 and 34 years, 37.5% were nurses, 18.7% were pharmacists, 17.2% were medical doctors and only one was a microbiologist. Overall, 75% of the HCWs had good knowledge, 84% were highly aware and 84% had good practices regarding AMU, AMR and AMS. Most of the HCWs (90.6%) responded that they had a multidisciplinary AMS team at their hospitals and were implementing the use of the WHO AWaRe classification of antibiotics.

Conclusion

This study found good knowledge levels, high awareness and good practices regarding AMU, AMR and AMS among HCWs who were involved in the implementation of AMS activities in hospitals in Zambia. Additionally, most hospitals have been conducting AMS training and implementing the use of the WHO AWaRe classification of antibiotics. However, there is still a need to address some identified gaps in AMU and AMR through the strengthening of AMS activities in hospitals.
Model checking distributed temporal logic
Authors: Dionísio Francisco , Ramos Jaime , Subtil Fernando , Viganò Luca
Published: May 2024

The distributed temporal logic (DTL) is a logic for reasoning about temporal properties of distributed systems from the local point of view of the system’s agents, which are assumed to execute sequentially and to interact by means of synchronous event sharing. Different versions of DTL have been provided over the years for a number of different applications, reflecting different perspectives on how non-local information can be accessed by each agent. In this paper, we propose an automata-theoretic model checking algorithm for DTL. To this end, we propose a notion of distributed transition system that will be used to specify the system to be verified. The properties that the system should meet are specified in DTL. In order to capture the models of these properties, we propose the notions of generalized distributed Büchi automaton and of distributed Büchi automaton. With these concepts, we are able to adapt results from automata-theoretic approaches to model checking in LTL to the distributed case.
Establishment of artificial intelligence model for precise histological subtyping of lung adenocarcinoma and its application to quantitative and spatial analysis
Authors: Miura Eisuke , Emoto Katsura , Abe Tokiya , Hashiguchi Akinori , Hishida Tomoyuki , Asakura Keisuke , Sakamoto Michiie
Published: May 2024

Background

The histological subtype of lung adenocarcinoma is a major prognostic factor. We developed a new artificial intelligence model to classify lung adenocarcinoma images into seven histological subtypes and adopted the model for whole-slide images to investigate the relationship between the distribution of histological subtypes and clinicopathological factors.

Methods

Using histological subtype images, which are typical for pathologists, we trained and validated an artificial intelligence model. Then, the model was applied to whole-slide images of resected lung adenocarcinoma specimens from 147 cases.

Result

The model achieved an accuracy of 99.7% in training sets and 90.4% in validation sets consisting of typical tiles of histological subtyping for pathologists. When the model was applied to whole-slide images, the predominant subtype according to the artificial intelligence model classification matched that determined by pathologists in 75.5% of cases. The predominant subtype and tumor grade (using the WHO fourth and fifth classifications) determined by the artificial intelligence model resulted in similar recurrence-free survival curves to those determined by pathologists. Furthermore, we stratified the recurrence-free survival curves for patients with different proportions of high-grade components (solid, micropapillary and cribriform) according to the physical distribution of the high-grade component. The results suggested that tumors with centrally located high-grade components had a higher malignant potential (P < 0.001 for 5–20% high-grade component).

Conclusion

The new artificial intelligence model for histological subtyping of lung adenocarcinoma achieved high accuracy, and subtype quantification and subtype distribution analyses could be achieved. Artificial intelligence model therefore has potential for clinical application for both quantification and spatial analysis.