bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Optimized and Reduced Chemical Kinetic Model for Hydrogen and Natural Gas Blends Combustion in Industrial Gas Turbines
Authors: Rahman Ramees K. , Kancherla Raghu , Vogel Gregory , Vasu Subith S. 
Published: August 2024

Abstract
Natural gas is one of the common fuels that is used in gas turbines for power generation. Due to its interest in power generation and other applications, there are several chemical kinetic models available in the literature for natural gas. The power generation sector is moving toward decarbonization and there has been increased interest in replacing conventional fuels with fuels that produce less/zero carbon emissions like hydrogen. Pure hydrogen has a very wide flammability range and poses risks related to flashback and high thermal NOx production. Blending hydrogen with natural gas helps in having better control over the fuel properties. However, the literature lacks well-validated chemical kinetic models for the combustion of hydrogen blended natural gas for undilute mixtures at gas turbine-relevant conditions (8–16 bar). Hence, in this work, we develop a detailed chemical kinetic model for hydrogen-blended natural gas and validate it with a wide range of experimental data for both dilute and undilute mixtures relevant to gas turbine operating conditions. We outline the strengths and weaknesses of the current mechanism to aid future users of our chemical kinetic mechanism. The detailed chemical kinetic mechanism is then reduced to two smaller versions (60 species and 44 species mechanisms) without significant loss in accuracy using Directed Relation Graph with Error Propagation (DRGEP). To improve the prediction for pure hydrogen combustion while retaining all other predictive capabilities, an optimization is carried out for the most sensitive reactions for hydrogen combustion. The resultant mechanism can predict a wide range of experimental results with the least cumulative error.
Teaching Aero-Engine Performance: From Analytics to Hands-On Exercises Using Gas Turbine Performance Software
Authors: Jeschke Peter , Koschel Wolfgang , Klumpp Christian , Weintraub Daniel 
Published: August 2024

Abstract
In this paper, we present an approach for teaching turbojet engine performance that combines mathematical analysis with the use of performance software to provide students with a comprehensive and in-depth understanding of engine performance and how it is affected by design parameter choices. In the first part, we present the derivation of a universally valid analytical model for turbojet engine cycle design, which is the basis of the propulsion courses at RWTH Aachen University. The analytical model allows for the calculation of specific thrust as well as thermal and propulsive efficiencies as a function of pressure ratios and burner exit temperature. These are all expressed as differentiable functions. Their mathematical extremes form a basis for examining the intricate relationships in turbojet engine design. In the second part, we move from theory to practice. We utilize the GasTurb software, computing turbojet engine cycles for a wide range of cycle design parameters. The analytically derived trends are validated and errors introduced by simplifications are assessed. Differences between the analytical approach and software-based performance simulations of real engines, like temperature-dependent gas properties and secondary air systems, are emphasized and discussed, thus providing a bridge to real-world applications. In summary, this paper describes a two-step approach to teaching turbojet engine design using analytics and performance software. Each approach alone can be used to enrich and extend existing performance courses. Combining the approaches has significant benefits, improving understanding and inspiring students to pursue further research in the field of propulsion.
A Perspective on the Process and Turbomachinery Design of Compressed Air Energy Storage Systems
Authors: Maffulli Gianfranco , Grimaldi Angelo , McGillis Andrew , Succi Lorenzo , Przybytko Przemyslaw , Maceli Nicola , Brown David , Brooke Graham , Earle Scott 
Published: August 2024

Abstract
The present paper will describe the Baker Hughes experience in the development of the turbomachinery equipment for Hydrostor's advanced compressed air energy storage (A-CAES) system. At the core of a compressed air energy storage (CAES) plant, there is an air compressing system, followed by an air expander used to recover the stored energy. To achieve a reliable and effective solution, the expander is obtained from the architecture of Baker Hughes steam turbines, which was adapted to match the specific process needs. The criticalities that were addressed and solved to derive the expanders from the original steam turbine are presented. Specifically, the paper describes the activities performed to optimize the inlet and exhaust sections of each segment, the development of the blades for high atmospheric volume flow, and the implications that thermal transients have on the machine reliability. The inlet and exhaust sections were arranged according to the layout constraints, which were set to mitigate the effects of the thermal stresses and to reduce the weight to facilitate the machine transportation, while maintaining high aero-performance. As for the expander, a single-body configuration was selected to optimize capital expenditures and reduce leakage to atmosphere. A new set of blades derived from Baker Hughes's Steam Turbine stages were developed. This new stage is characterized by rotating blades with high radius ratio (HRR); therefore, an optimization strategy was adopted to include the mechanical constraints from the beginning of the design cycle and obtain a final geometry that can be used with different flow path and operating conditions. Finally, the three-dimensional full Navier Stokes Computational fluid dynamics analysis was used to assess the performance of the new stages in nominal and off-design conditions. A detailed analysis of the thermal transient of the expander parts with finite element analysis methods was performed to assess the life expectations of the equipment. The finite element analysis results are discussed in the paper to show the capability of the machine to sustain an extremely fast start up sequence. Compressor train is characterized by a multiple body configuration. A detailed optimization was performed to improve the efficiency and the availability of the selected solution. The low-pressure axial compressor discharge section has been optimized to reduce losses and a detailed study of rotor has been performed to evaluate the capability to withstand a high number of start and stop cycles.
Vision Is Not Required to Elicit Balance Improvements From Beam Walking Practice
Authors: Richer Natalie , Peterson Steven M. , Ferris Daniel P. 
Published: August 2024

Background: Beam walking is a highly studied assessment of walking balance. Recent research has demonstrated that brief intermittent visual rotations and occlusions can increase the efficacy of beam walking practice on subsequent beam walking without visual perturbations. We sought to examine the influence of full vision removal during practice walking on a treadmill-mounted balance beam. Although visual disruptions improved performance of this task, we hypothesized that removing visual feedback completely would lead to less balance improvements than with normal vision due to the specificity of practice. Methods: Twenty healthy young adults trained to walk at a fixed speed on a treadmill-mounted balance beam for 30 min, either with, or without, normal vision. We compared their balance pre-, during, and posttraining by calculating their step-offs per minute and the percentage change in step-offs per minute. Results: Balance improved in both groups after training, with no significant difference in percentage change in step-offs between the normal vision and the no vision participants. On average, the no vision participants had twice as many step-offs per minute as the normal vision group during training. Conclusion: Although previous experiments show that intermittent visual perturbations led to large enhancements of the effectiveness of beam walking training, completely removing visual feedback did not alter training effectiveness compared with normal vision training. It is likely a result of sensory reweighting in the absence of vision, where a greater weight was placed on proprioceptive, cutaneous, and vestibular inputs.
Metabolic pathway engineering of high-salinity-induced overproduction of L-proline improves high-salinity stress tolerance of an ectoine-deficient
Halomonas elongata
Authors: Khanh Huynh Cong , Kaothien-Nakayama Pulla , Zou Ziyan , Nakayama Hideki 
Published: August 2024

ABSTRACT

Halophilic bacteria have adapted to survive in high-salinity environments by accumulating amino acids and their derivatives as organic osmolytes. L-Proline (Pro) is one such osmolyte that is also being used as a feed stimulant in the aquaculture industry.
Halomonas elongata
OUT30018 is a moderately halophilic bacterium that accumulates ectoine (Ect), but not Pro, as an osmolyte. Due to its ability to utilize diverse biomass-derived carbon and nitrogen sources for growth,
H. elongata
OUT30018 is used in this work to create a strain that overproduces Pro, which could be used as a sustainable Pro-rich feed additive. To achieve this, we replaced the coding region of
H. elongata
OUT30018’s Ect biosynthetic operon with the artificial self-cloned

proB
m1
AC

gene cluster that encodes the Pro biosynthetic enzymes: feedback-inhibition insensitive mutant γ-glutamate kinase (γ-GK
D118N/D119N
), γ-glutamyl phosphate reductase, and pyrroline-5-carboxylate reductase. Additionally, the
putA
gene, which encodes the key enzyme of Pro catabolism, was deleted from the genome to generate
H. elongata
HN6. While the Ect-deficient
H. elongata
KA1 could not grow in minimal media containing more than 4% NaCl,
H. elongata
HN6 thrived in the medium containing 8% NaCl by accumulating Pro in the cell instead of Ect, reaching a concentration of 353.1 ± 40.5 µmol/g cell fresh weight, comparable to the Ect accumulated in
H. elongata
OUT30018 in response to salt stress. With its genetic background,
H. elongata
HN6 has the potential to be developed into a Pro-rich cell factory for upcycling biomass waste into single-cell feed additives, contributing to a more sustainable aquaculture industry.

IMPORTANCE

We report here the evidence for
de novo
biosynthesis of Pro to be used as a major osmolyte in an ectoine-deficient
Halomonas elongata
. Remarkably, the concentration of Pro accumulated in
H. elongata
HN6 (

∆ectABC::mCherry-proB
m1
AC ∆putA

) is comparable to that of ectoine accumulated in
H. elongata
OUT30018 in response to high-salinity stress. We also found that among the two γ-glutamate kinase mutants (γ-GK
D118N/D119N
and γ-GK
D154A/E155A
) designed to resemble the two known
Escherichia coli
feedback-inhibition insensitive γ-GK
D107N
and γ-GK
E143A
, the γ-GK
D118N/D119N
mutant is the only one that became insensitive to feedback inhibition by Pro in
H. elongata
. As Pro is one of the essential feed additives for the poultry and aquaculture industries, the genetic makeup of the engineered
H. elongata
HN6 would allow for the sustainable upcycling of high-salinity waste biomass into a Pro-rich single-cell eco-feed.
Mouse hepatitis virus JHMV I protein is required for maximal virulence
Authors: Lowery Shea A. , Schuster Noah , Wong Lok-Yin Roy , Carrillo Thomas , Peters Erin , Odle Abby , Sariol Alan , Cesarz Isabella , Li Pengfei , Perlman Stanley 
Published: August 2024

ABSTRACT

Betacoronaviruses
encode a conserved accessory gene within the +1 open reading frame (ORF) of nucleocapsid called the internal N gene. This gene is referred to as “I” for mouse hepatitis virus (MHV), ORF9b for severe acute respiratory CoV (SARS-CoV) and SARS-CoV-2, and ORF8b for Middle East respiratory syndrome CoV (MERS-CoV). Previous studies have shown ORF8b and ORF9b have immunoevasive properties, while the only known information for MHV I is its localization within the virion of the hepatotropic/neurotropic A59 strain of MHV. Whether MHV I is an innate immune antagonist or has other functions has not been evaluated. In this report, we show that the I protein of the neurotropic JHM strain of MHV (JHMV) lacks a N terminal domain present in other MHV strains, has immunoevasive properties, and is a component of the virion. Genetic deletion of JHMV I (rJHMV
IΔ57-137
) resulted in a highly attenuated virus both
in vitro
and
in vivo
that displayed a post RNA replication/transcription defect that ultimately resulted in fewer infectious virions packaged compared with wild-type virus. This phenotype was only seen for rJHMV
IΔ57-137
, suggesting the structural changes predicted for A59 I altered its function, as genetic deletion of A59 I did not change viral replication or pathogenicity. Together, these data show that JHMV I both acts as a mild innate immune antagonist and aids in viral assembly and infectious virus production, and suggest that the internal N proteins from different betacoronaviruses have both common and virus strain-specific properties.

IMPORTANCE
CoV accessory genes are largely studied in overexpression assays and have been identified as innate immune antagonists. However, functions identified after overexpression are often not confirmed in the infected animal host. Furthermore, some accessory proteins are components of the CoV virion, but their role in viral replication and release remains unclear. Here, we utilized reverse genetics to abrogate expression of a conserved CoV accessory gene, the internal N (“I”) gene, of the neurotropic JHMV strain of MHV and found that loss of the I gene resulted in a post replication defect that reduced virion assembly and ultimately infectious virus production, while also increasing some inflammatory molecule expression. Thus, the JHMV I protein has roles in virion assembly that were previously underappreciated and in immunoevasion.
Protein-coding circular RNA enhances antiviral immunity via JAK/STAT pathway in
Drosophila
Authors: Guo Dongyang , Xu Wen , Cui Ting , Rong Qiqi , Wu Qingfa 
Published: August 2024

ABSTRACT

RNA interference (RNAi) drives powerful antiviral immunity in plants and animals so that many viruses must express viral suppressor of RNAi (VSR) to establish virulent infection. However, little is known about the immune responses conferring resistance against viruses that have evolved the counter-defensive strategy to suppress antiviral RNAi. In this study, we discover that
Drosophila
cells infected with
Drosophila
C virus (DCV), a natural viral pathogen of
Drosophila
known to harbor a potent VSR, exhibit heightened expression of circular RNA circZfh1. circZfh1 confers virus resistance in the presence of viral suppression of antiviral RNAi. Furthermore, we validate that circZfh1 encodes a 274-amino acid protein, CRAV, essential for its antiviral activity. Notably, CRAV differs from its parental Zfh1 gene in a different reading frame, with the C-terminal 69 amino acids unique to CRAV. Our analysis also reveals the presence of CRAV in species within the melanogaster subgroup, with the C-terminal unique fragment undergoing accelerated evolution. Expression of CRAV upregulates the expression of the cytokine Upd3, which binds to its receptor, stimulating the JAK-STAT pathway and enhancing the immune response to DCV infection. Notably, CRISPR/Cas9 knockout of circZfh1 significantly enhances DCV replication
in vitro
and
in vivo
, with circZfh1-knockout adult flies displaying heightened disease susceptibility to DCV. In summary, our findings unveil a
Drosophila
protein-coding circular RNA that activates an innate immune signaling pathway crucial for virus resistance following the suppression of antiviral RNAi by viruses, thereby elucidating a novel counter-defensive strategy.

IMPORTANCE

Eukaryotic hosts possess a complex, multilayered immune system that guards against pathogen invasion. In fruit flies, RNA interference (RNAi) drives robust antiviral immunity, prompting many viruses to express viral suppressors of RNAi (VSRs) to establish virulent infections. However, little is known about immune responses that confer resistance against viruses with potent VSRs. In this study, we discovered that
Drosophila
cells infected with
Drosophila
C virus (DCV), a natural viral pathogen possessing a potent VSR, upregulated the expression of circular RNA circZfh1. circZfh1 exhibits DCV-specific antiviral activity, encoding a 274-amino acid protein, CRAV, crucial for its antiviral effects. As a different reading frame from its parental Zfh1 gene, the C-terminal 69 amino acids are unique to CRAV, undergoing faster evolution. CRAV activates the JAK-STAT pathway, enhancing the immune response to DCV infection. Therefore, our work uncovers a new strategy for suppressing viral counter-defense through protein-coding circular RNA in fruit flies.
Microbiology of human spaceflight: microbial responses to mechanical forces that impact health and habitat sustainability
Authors: Nickerson Cheryl A. , McLean Robert J. C. , Barrila Jennifer , Yang Jiseon , Thornhill Starla G. , Banken Laura L. , Porterfield D. Marshall , Poste George , Pellis Neal R. , Ott C. Mark 
Published: August 2024

SUMMARY
Understanding the dynamic adaptive plasticity of microorganisms has been advanced by studying their responses to extreme environments. Spaceflight research platforms provide a unique opportunity to study microbial characteristics in new extreme adaptational modes, including sustained exposure to reduced forces of gravity and associated low fluid shear force conditions. Under these conditions, unexpected microbial responses occur, including alterations in virulence, antibiotic and stress resistance, biofilm formation, metabolism, motility, and gene expression, which are not observed using conventional experimental approaches. Here, we review biological and physical mechanisms that regulate microbial responses to spaceflight and spaceflight analog environments from both the microbe and host-microbe perspective that are relevant to human health and habitat sustainability. We highlight instrumentation and technology used in spaceflight microbiology experiments, their limitations, and advances necessary to enable next-generation research. As spaceflight experiments are relatively rare, we discuss ground-based analogs that mimic aspects of microbial responses to reduced gravity in spaceflight, including those that reduce mechanical forces of fluid flow over cell surfaces which also simulate conditions encountered by microorganisms during their terrestrial lifecycles. As spaceflight mission durations increase with traditional astronauts and commercial space programs send civilian crews with underlying health conditions, microorganisms will continue to play increasingly critical roles in health and habitat sustainability, thus defining a new dimension of occupational health. The ability of microorganisms to adapt, survive, and evolve in the spaceflight environment is important for future human space endeavors and provides opportunities for innovative biological and technological advances to benefit life on Earth.
Retrieval of refluxed Onyx cast during a paediatric AVM embolisation
Authors: Kishore Kislay , van Adel Brian 
Published: August 2024

Endovascular embolisation of arteriovenous malformations (AVM) has been greatly facilitated by liquid embolic agents. While advancements in catheter technology and techniques of creating a proximal plug minimise the risk of inadvertent proximal reflux of the embolysate, this remains one of the main complications associated with use of liquid embolics.We report a case of paediatric AVM embolisation which was complicated by parent vessel occlusion due to inadvertent proximal reflux of the embolysate in pericallosal artery. This was safely and effectively rescued using a stent retriever manoeuvre, following similar principles and tenets as in endovascular thrombectomy in stroke. This is the first case report of using a newer smaller 3 mm stentriever in a paediatric medium vessel occlusion, although for a different aetiology but with the same goal.Bail-out or rescue strategy as presented here is an important addition to neurointerventionalists’ armamentarium to salvage a non-targeted migration of liquid embolic agent.
Protein-losing enteropathy as a result of colon polyposis and colon cancer: a multidisciplinary approach to diagnosis and treatment
Authors: Kuipers Hendrien , van Westreenen Henderik L , Moll Freek C P , de Vos tot Nederveen Cappel Wouter H 
Published: August 2024

A man in his 60s presented to our emergency department with severe peripheral pitting oedema, weight gain, dyspnoea and diarrhoea. Blood tests showed a hypoalbuminaemia of 15 g/L. A suspicion of protein-losing enteropathy arose after the exclusion of albuminuria, cardiac failure, protein deficiency and liver cirrhosis. An abdominal CT scan revealed a wall thickening of the colon, and a subsequent colonoscopy identified multiple large obstructive polyps in the ascending colon. The patient underwent a right hemicolectomy which revealed the presence of tubulovillous polyps and a pT2N0 colon carcinoma. Following surgery, the patient experienced clinical improvement with normalisation of serum albumin and resolution of the oedema.Protein-losing enteropathy should be considered an underlying syndrome in patients with peripheral oedema and hypoalbuminaemia in the absence of cardiac failure, proteinuria, malnutrition and hepatic disease. This diagnostic process requires a multidisciplinary approach. For adequate treatment, the primary cause of protein-losing enteropathy needs to be investigated.
Carpal tunnel syndrome and occupational hand exposures: a Danish nationwide cohort study
Authors: Tabatabaeifar Sorosh , Dalbøge Annett 
Published: August 2024

ObjectivesThe aim was to examine exposure–response relations between occupational hand exposures and carpal tunnel syndrome (CTS) and to compare the relation between surgery-treated and non-surgery-treated CTS. The secondary aim was to study sex-specific differences in exposure–response relations.MethodsWe conducted a nationwide register-based cohort study of all persons born in Denmark (1945–1994). During follow-up (2010–2013), we identified first-time events of CTS. Occupational hand exposure estimates the year before each follow-up year were obtained by linking individual occupational codes with a job exposure matrix. We used multivariable logistic regression equivalent to discrete survival analysis based on sex and surgery. The excess fraction of cases was calculated.ResultsFor both sexes, exposure–response relations were found for all occupational hand exposures. Among men, we found ORadjof 3.6 (95% CI 3.2 to 3.8) for hand-related force, 2.9 (95% CI 2.5 to 3.2) for repetitive hand movements, 3.8 (95% CI 2.7 to 5.2) for non-neutral hand posture and 2.5 (95% CI 2.2 to 2.7) for hand-arm vibration in the highest exposure groups. For combined exposure (hand load), ORadjwas 3.5 (95% CI 3.1 to 4.0). Slightly higher ORsadjwere generally found for surgery-treated CTS compared with non-surgery-treated CTS for both sexes. When comparing sex, somewhat higher ORsadjwere found among men. The excess fraction was 42%.ConclusionsOccupational hand exposures carried a 3-5-fold increased risk of CTS with slightly higher risks for surgery-treated compared with non-surgery-treated CTS. Even though CTS occurs more frequently among women, somewhat higher exposure–response relations were found for men compared with women. In the general working population, a substantial fraction of first-time CTS could be related to occupational hand exposures.