bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Multi-Stage Turbine Stator Design for Improved Performance Retention
Authors: Jameson Heather K. , Longley John P. 
Published: December 2023

Abstract
An experimental and computational investigation has been undertaken into the effects of deterioration of the first-stage rotor-shroud knife-edge seal clearance in a two-stage turbine that has engine-representative cavity geometries. Four values of deterioration were investigated which cover the new-condition to old-condition knife-edge seal clearance. Measurements within the first-stage rotor-shroud cavity show that whilst the leakage mass flowrate increases with deterioration, the angle at which the leakage flow approaches the downstream stator is essentially fixed and independent of the flow coefficient. This agrees with a simple over-tip leakage model. Because of the engine-representative cavity geometry, the over-shroud-leakage flow undergoes little mixing when it re-enters the mainstream and approaches the downstream stator at more than 60-deg negative incidence. Detailed measurements at the exit of the second-stage stator identified two large positive vortices which were not consistent with the horseshoe vortex model for secondary flow. A computational investigation revealed that one vortex originates from the rolling-up within the stator passage of the streamwise vorticity sheet associated with the first-stage rotor over-shroud leakage. This roll-up vortex cannot be eliminated. The second vortex is generated within the stator passage by the separation of the over-shroud-leakage flow at the leading edge due to the large negative incidence. It was hypothesized that this separation vortex might be eliminated by locally redesigning the stator. A new stator was designed, manufactured, and tested. As predicted, the roll-up vortex was still present, but the separation vortex was eliminated. For all the values of deterioration tested, the entropy loss coefficient of the new stator and the unchanged second-stage rotor were reduced. It is estimated that the new stator would improve the lifetime average efficiency by 0.5% compared to the original.
Finite Element Analysis on Thermoelastic Instability of Multidisc Clutches Involving Deformation Modes of Multilayer Material Friction Disc
Authors: Suo Yiran , Cui Hongwei , Mei Bizhou , Li Donghui , Jiang Yuyu , Sun Hao , Zhang Lingqing 
Published: December 2023

Abstract
A two-dimensional finite element model was developed to investigate thermoelastic instability in multilayered friction discs with finite thickness, considering the deformation modes of the steel core. The model was used to simulate four unstable modes that can occur during the engagement process, and the Fourier reduction was applied to calculate the change in critical speed under these modes. Additionally, the influence of thermal physical parameters, including the elastic modulus, thermal expansion coefficient, Poisson’s ratio, and thermal conductivity of the friction pair, on thermoelastic instability was examined. The findings indicate that the critical speed of the friction pair is lower under the symmetric (friction disc)–antisymmetric (steel disc) mode compared to the other three modes. Consequently, the symmetric–antisymmetric mode is the first to be excited and serves as the dominant mode during thermoelastic instability. Moreover, there exists a specific wave number at which the system exhibits the lowest critical speed and poorest stability. Enhancing the thermal conductivity of the friction disc and steel disc, as well as reducing the thermal expansion coefficient of the steel disc and the elastic modulus and Poisson’s ratio of both discs, can improve the thermoelastic stability of the friction pair. Notably, the thermal expansion coefficient of the friction disc has minimal impact on thermoelastic instability. These results provide a theoretical foundation for exploring the relationship between the thermal failure of friction pairs and rotational speed, as well as optimizing overall performance design.
An Anisotropic Side Contact Model Based on the Peak Description Method of Surface Profile
Authors: Fan Lingsong , Wang Shijun , Li Pengyang 
Published: December 2023

Abstract
In contact models, traditional profile description methods are based on all sampling points of the profile. The methods can only describe the features in the height direction of profile, but are difficult to describe the profile features perpendicular to the height direction, which is the main obstacle to side contact modeling. In this paper, a profile description method based on peaks is proposed, which enables the profile features perpendicular to the height direction of the profile to be expressed. The statistical distribution law of the horizontal distances perpendicular to the height direction of the profile between adjacent asperities on anisotropic contact surfaces is investigated for the first time, and it is found that the distribution of the horizontal distances is very close to the normal distribution, but the values are different in different texture directions. The distribution law of the height differences between adjacent asperities is also investigated and is found to be close to a normal distribution, but the numerical values are different from the normal distribution of profile heights. Based on the results, the distribution function of the contact angle widely used in side contact model is replaced, and a new side contact model is proposed. By the model, the effects of the statistical parameters of surface profile and the material parameters of surfaces on the surface contact characteristics are investigated. The results of investigation show that the effect of the standard deviations of the horizontal distances between asperities in different texture directions on the normal contact stiffness between surfaces is obvious, and the normal contact stiffness will decrease with the increase of the standard deviation of the horizontal distances in any direction.
Study on Oil Supply Characteristics of Connecting Rod Small End Bearing With Splash Lubrication by Smooth Particle Hydrodynamics Method
Authors: Niu Penghao , Fu Hongyu , Zhang Hao , Guo Yiqiao , Stelmakh Oleksandr 
Published: December 2023

Abstract
The lubricating oil distribution significantly impacts the lubrication and cooling of the connecting rod small end bearing during the splash lubrication. This study investigates the oil supply for the small end bearing with splash lubrication utilizing the smoothed-particle hydrodynamics. The oil distribution and inlet volume are analyzed under various engine speeds. The results reveal that the oil moves close to the piston surface and hardly enters the oil bores, resulting in oil wastage. The oil entering the bores might be thrown out due to the inertia, causing the oil inlet volume to fluctuate. With increasing engine speeds, the total oil inlet volume under the quasi-steady-state gradually diminishes, exacerbating the lubrication conditions.
A Universal Mixing Rule for the High-Pressure Viscosity of Oil/Refrigerant Mixtures
Authors: Bair Scott , Harris Tequila 
Published: December 2023

Abstract
Bearing life analysis for the rolling element bearings in refrigeration compressors requires an accurate estimate of the film thickness. An alternative is offered here to the experimentally challenging pressure–viscosity measurements of oils diluted by refrigerants or the film thickness measurements of the same in an optical rig.
(p)ppGpp is required for virulence of
Shigella flexneri
Authors: Kago Grace , Turnbough Charles L. , Salazar Juan Carlos , Payne Shelley M. 
Published: December 2023

ABSTRACT

Infection by the enteric pathogen
Shigella flexneri
requires transit through the gastrointestinal tract and invasion of and replication within the cells of the host colonic epithelium. This process exposes the pathogen to a range of diverse microenvironments. Furthermore, the unique composition and physical environment of the eukaryotic cell cytosol represents a stressful environment for
S. flexneri
, and extensive physiological adaptations are needed for the bacterium to thrive. In this work, we show that disrupting synthesis of the stringent response alarmone (p)ppGpp in
S. flexneri
diminished expression of key virulence genes, including
ipaA, ipaB, ipaC,
and
icsA
, and it reduced bacterial invasion and intercellular spread. Deletion of the (p)ppGpp synthase gene
relA
alone had no effect on
S. flexneri
virulence, but disruption of both
relA
and the (p)ppGpp synthase/hydrolase gene
spoT
resulted in loss of (p)ppGpp synthesis and virulence. While the
relA spoT
deletion mutant was able to invade a cultured human epithelial cell monolayer, albeit at reduced levels, it was unable to maintain the infection and spread to adjacent cells, as indicated by loss of plaque formation. Complementation with
spoT
on a plasmid vector restored plaque formation. Thus, SpoT alone is sufficient to provide the necessary level of (p)ppGpp for virulence. These results indicate that (p)ppGpp is required for
S. flexneri
virulence and adaptation to the intracellular environment, adding to the repertoire of signaling pathways that affect
Shigella
pathogenesis.
DYRK1A is a multifunctional host factor that regulates coronavirus replication in a kinase-independent manner
Authors: Fu Zhen , Xiang Yixin , Fu Yanan , Su Zhelin , Tan Yubei , Yang Mengfang , Yan Yuanyuan , Baghaei Daemi Hakimeh , Shi Yuejun , Xie Shengsong , Sun Limeng , Peng Guiqing 
Published: December 2023

ABSTRACT

Coronaviruses (CoVs) pose a major threat to human and animal health worldwide, which complete viral replication by hijacking host factors. Identifying host factors essential for the viral life cycle can deepen our understanding of the mechanisms of virus–host interactions. Based on our previous genome-wide CRISPR screen of α-CoV transmissible gastroenteritis virus (TGEV), we identified the host factor dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A), but not DYRK1B, as a critical factor in TGEV replication. Rescue assays and kinase inhibitor experiments revealed that the effect of DYRK1A on viral replication is independent of its kinase activity. Nuclear localization signal modification experiments showed that nuclear DYRK1A facilitated virus replication. Furthermore, DYRK1A knockout significantly downregulated the expression of the TGEV receptor aminopeptidase N (
ANPEP
) and inhibited viral entry. Notably, we also demonstrated that DYRK1A is essential for the early stage of TGEV replication. Transmission electron microscopy results indicated that DYRK1A contributes to the formation of double-membrane vesicles in a kinase-independent manner. Finally, we validated that DYRK1A is also a proviral factor for mouse hepatitis virus, porcine deltacoronavirus, and porcine sapelovirus. In conclusion, our work demonstrated that DYRK1A is an essential host factor for the replication of multiple viruses, providing new insights into the mechanism of virus–host interactions and facilitating the development of new broad-spectrum antiviral drugs.

IMPORTANCE

Coronaviruses, like other positive-sense RNA viruses, can remodel the host membrane to form double-membrane vesicles (DMVs) as their replication organelles. Currently, host factors involved in DMV formation are not well defined. In this study, we used transmissible gastroenteritis virus (TGEV) as a virus model to investigate the regulatory mechanism of dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) on coronavirus. Results showed that DYRK1A significantly inhibited TGEV replication in a kinase-independent manner. DYRK1A knockout (KO) can regulate the expression of receptor aminopeptidase N (
ANPEP
) and endocytic-related genes to inhibit virus entry. More importantly, our results revealed that DYRK1A KO notably inhibited the formation of DMV to regulate the virus replication. Further data proved that DYRK1A is also essential in the replication of mouse hepatitis virus, porcine deltacoronavirus, and porcine sapelovirus. Taken together, our findings demonstrated that DYRK1A is a conserved factor for positive-sense RNA viruses and provided new insights into its transcriptional regulation activity, revealing its potential as a candidate target for therapeutic design.
Complete genomic sequencing of a
Pseudomonas putida
isolate derived from a patient suffering from chronic diarrheal infection in Hangzhou, China
Authors: Wang Qin , Salman Sayyed 
Published: December 2023

ABSTRACT

This study presents a comprehensive analysis of the genomic sequence of
Pseudomonas putida
isolate L2890hy, having a 6,733,472 bp chromosome size. This particular strain was obtained from a fecal sample of a patient suffering from acute diarrhea in Hangzhou, China, in 2020.
Constraints of boron and oxygen stable isotopes on dehydration fluids, sediment-derived melts, and crustal assimilation of the Toba volcanic system (Indonesia)
Authors: Liu Ping-Ping , Wang Dian-Bing , Zhou Mei-Fu , Li Xian-Hua , Li Qiu-Li , Gaetani Glenn A. , Monteleone Brian , Kamenetsky Vadim 
Published: December 2023

Abstract
Arc magmas are produced from the mantle wedge, with possible addition of fluids and melts derived from serpentinites and sediments in the subducting slab. Identification of various sources and their relevant contributions to such magmas is challenging; in particular, at continental arcs where crustal assimilation may overprint initial geochemical signatures. This study presents oxygen isotopic compositions of zoned olivine grains from post-caldera basalts and boron contents and isotopes of these basalts and glassy melt inclusions hosted in quartz and clinopyroxene of silicic tuffs in the Toba volcanic system, Indonesia. High-magnesian (≥87 mol% Fo [forsterite]) cores of olivine in the basalts have δ18O values ranging from 5.12‰ to 6.14‰, indicating that the mantle source underneath Toba is variably enriched in 18O. Olivine with &lt;87 mol% Fo has highly variable (4.8–7.2‰), but overall increased, δ18O values, interpreted to reflect assimilation of high δ18O crustal materials during fractional crystallization. Mass balance calculations constrain the overall volume of crustal assimilation for the basalts as ≤13%. The processes responsible for the 18O-enriched basaltic melts are further constrained by boron data that indicate the addition of &lt;0.1 wt% fluids to the mantle, &gt;40% of the fluids being derived from serpentinites and others from altered oceanic crust and sediments. This amount of fluids can increase δ18O of the magma by only ~0.02‰. Approximately 6–9% sediment-derived melt hybridization in the mantle wedge is further needed to yield basaltic melts with δ18O values in equilibrium with those of the high-Fo olivine cores. The cogenetic silicic tuffs, on the other hand, seem to record a higher proportion of fluid addition dominated by sediment-derived fluids to the mantle source, in addition to crustal assimilation. Our reconnaissance study therefore demonstrates the application of combined B and O isotopes to differentiate between melts and fluids derived from serpentinites and sediments in the subducted slab—an application that can be applied to arc magmas worldwide.
Effect of adverse perinatal outcomes on postpartum maternal mental health in low-income and middle-income countries: a protocol for systematic review
Authors: Fetene Samrawit Mihret , Haile Tsegaye Gebremedhin , Dadi Abel 
Published: December 2023

IntroductionMore than three-fourths of adverse perinatal outcomes (preterm, small for gestational age, low birth weight, congenital anomalies, stillbirth and neonatal death) occur in low-income and middle-income countries. These adverse perinatal outcomes can have both short-term and long-term consequences on maternal mental health. Even though there are few empirical studies on the effect of perinatal loss on maternal mental illness, comprehensive information on the impact of adverse perinatal outcomes in resource-limited settings is scarce. Therefore, we aim to systematically review and synthesise evidence on the effect of adverse perinatal outcomes on maternal mental health.Methods and analysisThe primary outcome of our review will be postpartum maternal mental illness (anxiety, depression, post-traumatic stress disorder and postpartum psychosis) following adverse perinatal outcomes. All peer-reviewed primary studies published in English will be retrieved from databases: PubMed, MEDLINE, CINAHL Ultimate (EBSCO), PsycINFO, Embase, Scopus and Global Health through the three main searching terms—adverse perinatal outcomes, maternal mental illness and settings, with a variant of subject headings and keywords. We will follow the Joanna Briggs Institute critical appraisal checklist to assess the quality of the studies we are including. The review findings will be reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. Estimate-based meta-analysis will be performed. We will assess heterogeneity between studies using the I2statistics and publication bias will be checked using funnel plots and Egger’s test. A subgroup analysis will be conducted to explore potential sources of heterogeneity (if available). Finally, the certainty of the evidence will be evaluated using the Grading of Recommendations, Assessment, Development and Evaluation approach.Ethics and disseminationSince this systematic review does not involve human participants, ethical approval is not required. The review will be submitted for publication in a peer-reviewed journal.PROSPERO registration numberCRD42023405980.
Factors influencing deviation from target temperature during targeted temperature management in postcardiac arrest patients
Authors: Ochiai Kanae , Otomo Yasuhiro 
Published: December 2023

BackgroundTargeted temperature management (TTM) is a recommended therapy for postcardiac arrest patients. Hyperthermia worsened the patient outcome, and overcooling increased the incidence of complications; therefore, a high-quality TTM is required. The target temperature tended to be modified worldwide after the TTM trial in 2013. Our institute modified the target temperature to 35°C in 2017. This study aimed to compare the conventional and modified protocols, assess the relationship between target temperature deviation and patient outcomes, and identify the factors influencing temperature deviation.MethodsThis single-centre, retrospective, observational study included adult out-of-hospital cardiac arrest patients who underwent TTM between April 2013 and October 2019. We compared the conventional and modified protocol groups to evaluate the difference in the background characteristics and details on TTM. Subsequently, we assessed the relationship of deviation (>±0.5°C, >37°C, or<33°C) rates from the target temperature with mortality and neurological outcomes. We assessed the factors that influenced the deviation from the target temperature.ResultsTemperature deviation was frequently observed in the conventional protocol group (p=0.012), and the modified protocol group required higher doses of neuromuscular blocking agents (NMBAs) during TTM (p=0.016). Other background data, completion of protocol, incidence of complications, mortality and rate of favourable neurological outcomes were not significantly different. The performance rate of TTM was significantly higher in the modified group than in the conventional protocol group (p<0.001). Temperature deviation did not have an impact on the outcomes. Age, sex, body surface area, NMBA doses and type of cooling device were the factors influencing temperature deviation.ConclusionsA target temperature of 35°C might be acceptable and easily attainable if shivering of the patients was well controlled using NMBAs. Temperature deviation did not have an impact on outcomes. The identified factors influencing deviation from target temperature might be useful for ensuring a high-quality TTM.
Exploring the Moho beneath the Northern Canadian Cordillera, with seismically constrained gravity inversion
Authors: Hayward Nathan , Schetselaar Ernst 
Published: December 2023

The geometry and depth of the Moho beneath the Northern Canadian Cordillera and adjacent North American craton are modeled through the application of both cokriging and 3-D inversion of gravity data, integrated with sparse seismic depth estimates. Models require a regional density correction, with lower densities beneath the Cordillera than the craton. The lower densities are primarily attributed to a reduction in upper mantle density, ascribed to thermal expansion under regionally higher temperatures. The eastern margin of this low-density zone is broadly aligned with the rapid westward shallowing of the lithospheric–asthenospheric boundary. From the Cordillera to the North American craton, the Moho is broadly flat at a depth of ∼32 km. A zone of deeper Moho (up to ∼38 km) beneath the Mistry Creek embayment has a modeled mantle density that is of a colder cratonic signature, akin to the Mackenzie craton, and is interpreted to represent the preserved remnants of an old rift basin that is a local focus of the diffuse seismicity. Southeast of the Fort Norman structure, seismicity is broadly focused along the eastern edge of the low-density zone. Major structures such as the Denali and Tintina faults, with 100’s km of right-lateral displacement, separate zones of higher and lower upper mantle density, supporting the interpretation of their continuation into the upper mantle. Within the North American craton, upper mantle density steadily increases toward the Great Bear magmatic zone but increases more rapidly beneath the Slave craton in tangent with a deepening of the Moho.
Quark masses and CKM hierarchies from $$S_4'$$ modular flavor symmetry
Authors: Abe Yoshihiko , Higaki Tetsutaro , Kawamura Junichiro , Kobayashi Tatsuo 
Published: December 2023

AbstractWe propose models to explain the hierarchies of the quark masses and mixing by utilizing the $$S_4^\prime $$

S
4
′

modular flavor symmetry. The hierarchy is realized by the modulus $$\tau $$
τ
stabilized at $$\textrm{Im}\,\tau \gg 1$$

Im

τ
≫
1

, where the residual $$\mathbb {Z}_4^T$$

Z
4
T

symmetry is approximately unbroken and the Froggatt–Nielsen mechanism works. It is found that the quark hierarchies are realized only in a few cases of quark representations. We study two models with assigning the modular weights, so that the observed quark hierarchies are explained in the cases of both small and large ratios of the top to bottom Yukawa couplings. We also argue that $$\mathcal {O}\left( {0.1}\right) $$

O

0.1

hierarchies of the $$\mathcal {O}\left( {1}\right) $$

O

1

coefficients and the spontaneous CP violation can be realized by imposing another $$S_3$$

S
3

modular symmetry.