bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal Part-Load Performance of Supercritical Carbon Dioxide Brayton Cycles During Inventory Control
Authors: Gupta Shrey Sahai , Kumar Pramod 
Published: October 2024

Abstract
Supercritical carbon dioxide (sCO2) cycles are gaining attention for their efficiency and low carbon footprint in power plants. This study focuses on optimizing the performance of a 5 MW simple recuperated sCO2 Brayton loop during inventory control, a recommended strategy for maximum part-load efficiencies. Variable speed operation of turbomachines is explored to enhance part-load efficiency across the operating range, contrasting with the baseline case of constant turbine and compressor speeds. The analysis, which is based on an analytical formulation and validated component models, reveals that part-load efficiency can be improved by variable speed operation of the turbomachines. Additionally, decoupled shaft systems are found to outperform coupled or single shaft systems. Further, part-load efficiency deterioration in case of constant speeds has been discussed in detail. A unique feature of this study is the modeling methodology; model for the compressor is derived by modifying an ideal gas compressor model to account for the behavior of a real gas compressor. Component matching is performed systematically to accurately estimate sCO2 cycle conditions. The results predicted by the model provide valuable insights on design of control strategy including inventory management for better response and improved efficiency while operating under part-load conditions.
Experimental Investigations on Carbon Segmented Seals With Smooth and Pocketed Pads
Authors: Jolly Pascal , Arghir Mihai , Kasahara Hidetoshi , Kimura Wataru 
Published: October 2024

Abstract
The present paper introduces experimental results for radial segmented seals operating at high rotating speed. These seals are made of three or more interlocking, carbon-graphite segments, in permanent contact with the rotor while also accommodating its dynamic displacements. Currently, many efforts are made to model these behaviors and for obtaining accurate leakage flowrate and friction torque predictions. A novel test rig fitted with a casing for measuring leakage and friction torque produced by two carbon segmented seals was developed. The tested seals were composed of three segments. Two types of segmented seals were tested: two seals with flat pads and one seal with pocketed pads. The seals were installed two by two in a casing and were simultaneously tested in a back to back arrangement. The process fluid was air, with a maximum inlet pressure of 0.3 MPa, while it was set to ambient at the outlet. The rotor diameter was 100 mm with a maximum rotating speed of 24,000 rpm. The main measurements were the inlet mass flowrate and friction torque produced by the two seals. Results show that the seal with pocketed pads produced higher leakage rates but lower friction torque compared to the smooth pads. This suggests that the seal with pocketed pads operated with segments completely lifted from the rotor surface. Mass flow rates measurements during run-up/coast-down tests revealed a hysteresis effect, which could be the consequence of segment tilt. The experimental results could also be useful to validate theoretical models.
High frequency of acquired virulence factors in carbapenemase-producing
Klebsiella pneumoniae
isolates from a large German university hospital, 2013–2021
Authors: Sattler Janko , Ernst Christoph M. , Zweigner Janine , Hamprecht Axel 
Published: October 2024

ABSTRACT

Carbapenemase-producing
Klebsiella pneumoniae
(CP-Kp) isolates are a public health concern as they can cause severe hospital-acquired infections that are difficult to treat. It has recently been shown that CP-Kp can take up virulence factors from hypervirulent
K. pneumoniae
lineages. In this study, 109 clinical CP-Kp isolates from the University Hospital Cologne were examined for the presence of acquired virulence factors using whole-genome sequencing and phenotypic tests, and results were linked to clinical data. The virulence factor
iuc
was present in 18/109 of the CP-Kp isolates. Other acquired virulence factors, such as
ybt
,
cbt
,
iro
,
rmpA/rmpA2
,
peg-344
, and hypervirulence-associated capsule types were detected in various combinations among these isolates. The
iuc
-positive isolates produced OXA-232 (
n
= 7), OXA-48 (
n
= 6), OXA-48+NDM (
n
= 3), NDM, and KPC (each
n
= 1), and 7/18 isolates were resistant to ceftazidime-avibactam, colistin, and/or cefiderocol. Four isolates carried hybrid plasmids that harbored acquired virulence factors alongside the carbapenemase genes
bla
NDM-1/5
or
bla
OXA-48
. In 15/18 patients,
iuc
-positive CP-Kp were isolated from a clinically manifest infection site. Among these, four patients had osteomyelitis, and four patients died from pneumonia with OXA-232-producing ST231 isolates, three of them as part of an outbreak. In conclusion, acquired virulence factors are frequently detected in various combinations in carbapenemase-producing
K. pneumoniae
isolates in Germany, warranting continuous monitoring of infections caused by these strains.
A realistic approach for evaluating antimicrobial surfaces for dry surface exposure scenarios
Authors: Cheong Yi Enn , Weyandt Ralph , Dewald Wilma , Tolksdorf Timo , Müller Laura , Braun Armin 
Published: October 2024

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 pandemic has raised public awareness about the importance of hygiene, leading to an increased demand for antimicrobial surfaces to minimize microbial contamination on high-touch surfaces. This is particularly relevant in public and private transportation settings, where surfaces frequently touched by individuals pose a significant, yet preventable, risk of infection transmission. Typically, the antimicrobial activity of surfaces is tested using test methods of the International Standards Organization, American Society for Testing and Materials, or Japanese Industrial Standards, which involve complete submersion in liquid, elevated temperature (37°C), and prolonged (24 h) contact periods. However, these conditions do not accurately represent real-world scenarios where surfaces are exposed to air. In this study, we propose a modified test method designed to better reflect real-life conditions in the intended end-use setting. The modifications included using deionized water instead of nutrient broth while preparing bacterial inoculum, applying a small test inoculum to the surface and allowing it to dry, maintaining ambient temperature and relative humidity throughout the contact period, and reducing the contact period to 4 h. With this modified approach, the antimicrobial activity of 20 samples was reassessed. This screening revealed that out of 20 samples, only 2 samples were effective against all species, while 8 samples demonstrated partial effectiveness against selected species, and 10 samples showed no significant effect. These findings highlight the inadequacy of the current test standard and emphasize the urgent necessity for revised and adapted testing method to ensure a reliable and accurate evaluation.

IMPORTANCE
The recent severe acute respiratory syndrome coronavirus 2 pandemic has sparked increased demand for antimicrobial surfaces to mitigate the risk of fomites-transmitted infection in both indoors and confined spaces. Commonly, the antimicrobial activity of these surfaces is assessed using test standards established by national standards bodies, which do not distinguish between different application scenarios. While these test standards are suitable for surfaces intended for submerged application, they are inappropriate for antimicrobial surfaces designed for dry surface exposure. The usage of these standards can lead to an overestimation of antimicrobial efficacy. Thus, this study introduces a modified dry exposure test method aimed at better reflecting real-life conditions in the intended end-use setting. Our results revealed the subpar antimicrobial performance of numerous samples, highlighting the necessity to revise and tailor the universal test standard to real-world scenarios in order to ensure a reliable and accurate evaluation.
Antibiotic tolerance among clinical isolates: mechanisms, detection, prevalence, and significance
Authors: Deventer Ashley T. , Stevens Claire E. , Stewart Amy , Hobbs Joanne K. 
Published: October 2024

SUMMARY

Antibiotic treatment failures in the absence of resistance are not uncommon. Recently, attention has grown around the phenomenon of antibiotic tolerance, an underappreciated contributor to recalcitrant infections first detected in the 1970s. Tolerance describes the ability of a bacterial population to survive transient exposure to an otherwise lethal concentration of antibiotic without exhibiting resistance. With advances in genomics, we are gaining a better understanding of the molecular mechanisms behind tolerance, and several studies have sought to examine the clinical prevalence of tolerance. Attempts have also been made to assess the clinical significance of tolerance through
in vivo
infection models and prospective/retrospective clinical studies. Here, we review the data available on the molecular mechanisms, detection, prevalence, and clinical significance of genotypic tolerance that span ~50 years. We discuss the need for standardized methodology and interpretation criteria for tolerance detection and the impact that methodological inconsistencies have on our ability to accurately assess the scale of the problem. In terms of the clinical significance of tolerance, studies suggest that tolerance contributes to worse outcomes for patients (e.g., higher mortality, prolonged hospitalization), but historical data from animal models are varied. Furthermore, we lack the necessary information to effectively treat tolerant infections. Overall, while the tolerance field is gaining much-needed traction, the underlying clinical significance of tolerance that underpins all tolerance research is still far from clear and requires attention.
Oxford Nanopore’s 2024 sequencing technology for
Listeria monocytogenes
outbreak detection and source attribution: progress and clone-specific challenges
Authors: Biggel Michael , Cernela Nicole , Horlbog Jule Anna , Stephan Roger 
Published: October 2024

ABSTRACT

Whole genome sequencing is an essential cornerstone of pathogen surveillance and outbreak detection. Established sequencing technologies are currently being challenged by Oxford Nanopore Technologies (ONT), which offers an accessible and cost-effective alternative enabling gap-free assemblies of chromosomes and plasmids. Limited accuracy has hindered its use for investigating pathogen transmission, but recent technology updates have brought significant improvements. To evaluate its readiness for outbreak detection, we selected 78
Listeria monocytogenes
isolates from diverse lineages or known epidemiological clusters for sequencing with ONT‘s V14 Rapid Barcoding Kit and R10.4.1 flow cells. The most accurate of several tested workflows generated assemblies with a median of one error (SNP or indel) per assembly. For 66 isolates, the cgMLST profiles from ONT-only assemblies were identical to those generated from Illumina data. Eight assemblies were of lower quality, with more than 20 erroneous sites each, primarily caused by methylations at the GAAGAC motif (5′-GAAG
6mA
C-3′/5′-GT
4mC
TTC-3′). This led to inaccurate clustering, failing to group isolates from a persistence-associated clone that carried the responsible restriction–modification system. Out of 50 methylation motifs detected among the 78 isolates, only the GAAGAC motif was linked to substantially increased error rates. Our study shows that most
L. monocytogenes
genomes assembled from ONT-only data are suitable for high-resolution genotyping, but further improvements of chemistries or basecallers are required for reliable routine use in outbreak and food safety investigations.
A Nanopore-sequenced high-quality genome of the
Bipolaris oryzae
strain Bo-1
Authors: Liu Meng , Yang Wei , Gu Xinyi , Xiao Yongxin , Yang Lei , Zhang Zhaowu , Wei Tong , Hsiang Tom , Zhang Yaling , Li Guotian 
Published: October 2024

ABSTRACT

Brown spot disease of rice caused by
Bipolaris oryzae
results in severe yield losses. A high-quality genome was assembled using Nanopore sequencing data, resulting in a 36-Mb nuclear genome with 19 contigs and a mitogenome. This assembly provides valuable genetic resources for investigations of rice-
B. oryzae
interactions.
Advancing microbiome research in Māori populations: insights from recent literature exploring the gut microbiomes of underrepresented and Indigenous peoples
Authors: Silk Ella T. , Bayer Simone B. , Foster Meika , Roy Nicole C. , Taylor Michael W. , Vatanen Tommi , Gearry Richard B. 
Published: October 2024

ABSTRACT

The gut microbiome plays vital roles in human health, including mediating metabolism, immunity, and the gut-brain axis. Many ethnicities remain underrepresented in gut microbiome research, with significant variation between Indigenous and non-Indigenous peoples due to dietary, socioeconomic, health, and urbanization differences. Although research regarding the microbiomes of Indigenous peoples is increasing, Māori microbiome literature is lacking despite widespread inequities that Māori populations face. These inequities likely contribute to gut microbiome differences that exacerbate negative health outcomes. Characterizing the gut microbiomes of underrepresented populations is necessary to inform efforts to address health inequities. However, for microbiome research to be culturally responsible and meaningful, study design must improve to better protect the rights and interests of Indigenous peoples. Here, we discuss barriers to Indigenous participation in research and the role disparities may play in shaping the gut microbiomes of Indigenous peoples, with a particular focus on implications for Māori and areas for improvement.
Identification and characterization of a carbohydrate recognition domain-like region in
Entamoeba histolytica
Gal/GalNAc lectin intermediate subunit
Authors: Zhang Hongze , Li Qingshan , Zhou Hang , Feng Meng , Zhao Yanqing , Zhou Ruixue , Chen Lijun , Tachibana Hiroshi , Cheng Xunjia 
Published: October 2024

ABSTRACT

Entamoeba histolytica
is an enteric protozoan parasite that causes human amebic colitis and extraintestinal abscesses. As a prerequisite for parasite colonization and invasion, adherence of
E. histolytica
is predominantly mediated by galactose (Gal)- and N-acetyl-d-galactosamine (GalNAc)-inhibitable lectins. The intermediate subunit (Igl) of Gal-/GalNAc-inhibitable lectin is a cysteine-rich protein containing multiple CXXC motifs and is considered a key factor affecting trophozoite’s pathogenicity. However, details of the function of Igl during parasite adherence remain unclear. Here, using segmentally expressed Igl proteins and a CHO cell model transfected with Igl fragments, we identified a carbohydrate-recognition domain (CRD)-like region between amino acids 989 and 1,088. Through single- and double-point mutations in the Igl segments, two core CXXC motifs responsible for carbohydrate recognition in the CRD-like region, which are highly conserved among several lectins, were confirmed. In addition to adhesion, the roles of CRD-like region and its core CXXC motifs in various pathogenic effects were further explored. To our knowledge, this is the first report showing an adhesion-related region in
E. histolytica
Igl. The identification and characterization of this CRD-like region provides further insights into molecular mechanisms underlying
E. histolytica
pathogenicity and also aids in the determination of a potential drug target in this parasite.

IMPORTANCE

Entamoeba histolytica
adhesion mainly depends on galactose (Gal)-/N-acetyl-d-galactosamine (GalNAc)-inhibitable lectins, subsequently triggering a series of amebic reactions. Among the three subunits of Gal-/GalNAc-inhibitable lectin, heavy subunit and intermediate subunit (Igl) have exhibited lectin activity, but that of Igl remains poorly understood. In this study, we confirmed a carbohydrate-recognition domain (CRD)-like limiting region in
E. histolytica
Igl and further identified its two core CXXC motifs responsible for carbohydrate recognition. Moreover, the role of Igl's CRD-like region and its CXXC motifs in hemolysis and pathogenic effects was explored. This is the first study to determine an adhesion-related region in
E. histolytica
Igl protein, providing a new reference direction for subsequent research studies. Since the potential homogeneity of galectin-2 in several mammals and Igl CRD-like region, it could be meaningful to relate the corresponding pathogeneses and phenotypes of these two proteins. Except for adhesion, studies on the involvement of Igl CRD-like region in different parasite–host interactions are also promising.
First isolation of
Campylobacter vicugnae
sp. nov. in humans suffering from gastroenteritis
Authors: Jehanne Quentin , Bénéjat Lucie , Azzi Martin Lamia , Korolik Victoria , Ducournau Astrid , Aptel Johanna , Ménard Armelle , Jauvain Marine , Aguilera Christophe , Doreille Alice , Mesnard Laurent , Eckert Catherine , Lehours Philippe 
Published: October 2024

ABSTRACT

The present study describes the first isolation of a recently described
Campylobacter
species,
Campylobacter vicugnae
, in humans. The isolates were recovered by two independent French laboratories in 2020 and 2022 from a man and a woman suffering from gastroenteritis. Biochemical and growth characteristics, and electron microscopy for these two strains indicated that they belong to
Campylobacter
genus.
16S rDNA
and GyrA-based phylogeny, as well as average nucleotide identity and
in silico
DNA-DNA Hybridization analyses revealed that both strains belong to the
Campylobacter vicugnae
species. Both isolates possess a complete cytolethal distending toxin (CDT) locus with
cdtA
,
cdtB,
and
cdt
C, and features of CDT activity were demonstrated
in vitro
with Caco-2 intestinal epithelial cells. Our data suggest that these two isolates of
C. vicugnae
were associated with gastroenteritis in humans and induced major cytopathogenic effects
in vitro
.
C. vicugnae
is likely to be a novel human pathogen, with a source of foodborne infection that needs to be determined.

IMPORTANCE

Campylobacter
species that display toxicity features are a worldwide public health issue. In clinical contexts, it is crucial to identify which isolate could be an urgent threat to a patient. Actual and widely used laboratory methods such as mass spectrometry or PCR may be flawed in the field of species identification. In contrast, the present study shows that next-generation sequencing allows to precisely identify isolates to species level that may have been omitted otherwise. Moreover, it helps to identify emerging species before they become a threat to human health. Recovery of a new
Campylobacter
species in human sample, such as the new species “
Campylobacter vicugnae
,” is an important step for the identification of emerging pathogens posing threat to global health.
Enhanced global terrestrial moisture from the Early Triassic to the Late Triassic: Evidence from extensive Neocalamites forests in North China
Authors: Wang Yuchong , Kuang Hongwei , Liu Yongqing , Zhao Fenghua , Peng Nan , Chen Xiaoshuai , Qi Kening , Li Jiyuan , Dong Guilin , Li Suping , Li Ya 
Published: October 2024

Abstract
Multistorey vegetation was reestablished in the Middle to Late Triassic following the end-Permian mass extinction, ultimately forming extensive forests worldwide. There are some cosmopolitan elements in these communities, such as the Neocalamites (Sphenophyta), that bear significant climatic implications. Here, we report an in situ fossil forest of the extinct Sphenophyta Neocalamites from the Chang-8 member of the Middle Triassic Yanchang Formation (ca. 242 Ma) in North China. The in situ pith casts of more than 210 Neocalamites, ranging in diameter from 6 cm to 35 cm with a spacing ranging from 0.1 m to 4.5 m, remain in their original growing positions at the Tongchuan, Jiyuan, and Huangling localities. Preliminary estimates suggest that the height of Neocalamites ranges from 15 m to 35 m, potentially reaching up to 70 m. Sedimentological analysis of plant-bearing deposits revealed that these Neocalamites plants grew along distributary channels within interdistributary swamps in humid delta plain environments. Neocalamites first appeared in the Late Permian, diversified during the last stage of the Middle Triassic, and occurred in different areas of the Pangaea supercontinent; this is believed to be coupled with Triassic global climatic wetting and terrestrial ecosystem recovery processes. Neocalamites, which formed the earliest monotypic stands of the Triassic during the Ladinian stage (ca. 242 Ma), serve as a paleontological proxy for global climatic wetting during the Triassic, indicating the wide-scale intensification of the hydrological cycle prior to the Late Triassic Carnian Pluvial Episode.
Water, sanitation and hygiene (WASH): the evolution of a global health and development sector
Authors: de Wit Sara , Luseka Euphrasia , Bradley David , Brown Joe , Bhagwan Jayant , Evans Barbara , Freeman Matthew C , Howard Guy , Ray Isha , Ross Ian , Simiyu Sheillah , Cumming Oliver , Chandler Clare I R 
Published: October 2024

Despite some progress, universal access to safe water, sanitation and hygiene (WASH) by 2030—a remit of Sustainable Development Goal 6—remains a distant prospect in many countries. Policy-makers and implementers of the WASH sector are challenged to track a new path. This research aimed to identify core orienting themes of the sector, as legacies of past processes, which can provide insights for its future. We reviewed global policy, science and programmatic documents and carried out 19 expert interviews to track the evolution of the global WASH sector over seven decades. We situated this evolution in relation to wider trends in global health and development over the same time period.With transnational flows of concern, expertise and resources from high-income to lower-income countries, the WASH sector evolved over decades of international institutionalisation of health and development with (1) a focus on technologies (technicalisation), (2) a search for generalised solutions (universalisation), (3) attempts to make recipients responsible for environmental health (responsibilisation) and (4) the shaping of programmes around quantifiable outcomes (metricisation). The emergent commitment of the WASH sector to these core themes reflects a pragmatic response in health and development to depoliticise poverty and social inequalities in order to enable action. This leads to questions about what potential solutions have been obscured, a recognition which might be understood as ‘uncomfortable knowledge’—the knowns that have had to be unknown, which resonate with concerns about deep inequalities, shrinking budgets and the gap between what could and has been achieved.