bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transient Multi-Fuel Performance Modelling of a Utility Scale Boiler
Authors: Johnson Michael D. , Hübel Moritz 
Published: September 2023

Abstract
Following the trends of integrating intermittent renewable energy into the electrical grids, design processes and tools for thermal power plants are changing. Utility-scale boilers are complex thermodynamic systems, which consist of components like combustors, heat exchangers, pumps, or valves. These components are well understood in principle and can be described with fundamental physical equations such as mass, energy, and species balances as well as heat transfer, and pressure loss correlations. Evolving computational performance and transient system simulation tools allow the coupling of these components and the creation of system models which support the design process to adapt to the energy market trends.
The paper will give insights into the underlying modelling approaches and assumptions for a commercial, 540MW boiler design process. System model validation for a wide load range will be shown based on plant measurement data. The paper will cover the implementation of an innovative dual-fuel combustion model, which allows switching from 100% coal operation to 100% natural gas operation. In addition, ramp-rate studies will be presented, affecting critical operational data such as temperature differences in critical headers causing thermal stress. The presented approach serves plant designers, owners, and operators to increase safety, reduce commissioning times and maximize output.
Numerical Modeling of an Elastohydrodynamic Seal Design for Supercritical CO2 Power Cycles
Authors: Cesmeci Sevki , Ejiogu Ikenna , Rahman Md Mahmudur , Hassan Mohammad Fuad , Xu Hanping , Tang Jing 
Published: September 2023

Abstract
Supercritical carbon dioxide (SCO2) leakage has been one of the major issues in sCO2 power cycles, penalizing the cycle efficiencies. The effect of the seal leakage on the cycle efficiency could be as high as 0.65% for a utility sCO2 power cycle. Therefore, there is a pressing need for effective sealing solutions to get the full benefit of sCO2 power generation technology. To offer a potential solution, we propose an Elasto-Hydrodynamic (EHD) seal that can work at elevated pressures and temperatures with low leakage and minimal wear. The EHD seal has a very simple, sleeve like structure, wrapping on the rotor with minimal initial clearance at 25 to 50μm levels. In this work, a proof-of-concept study for the proposed EHD seal was presented by using the Reynolds equation, Lame’s formula, Barus Equation, and Dowson-Higginson formula to model the pressure distribution along the seal clearance as well as the seal deformation. The numerical modeling of the seal was carried out in Matlab using its built-in ordinary differential equation solver. The seal was evaluated for a 2″ diameter test seal with a pressure range of 0.2 MPa to 20 MPa. At the high pressure of 20 MPa, the clearance height at the throat (ht) was found to be 24.7 μm which is about 50.6% than the initial seal clearance (h0) of 50 μm, which resulted in a mass flow rate of 0.00162 kg/s. The presented analytical study lays a solid foundation for future model developments that could be used in the design of the proposed EHD seal.
Failure Analysis of OTSG Tube in a Cogeneration Power Plant
Authors: Tina Wahida , Donaldson Elizabeth , Dickinson Thomas E. 
Published: September 2023

Abstract
Tube leakage is one of the most frequent causes of Once Through Steam Generator (OTSG) tube failure. A leaking tube was discovered within the OTSG unit of the Cogeneration Plant of 100 MW. The failed section of the tube was removed from the steam generator. Several metallurgical examinations of this tube segment were performed to identify the failure mode and cause. The results of the metallurgical evaluation revealed that the tubing was furnished to the chemical requirements of ASME Specification SB 407 and UNS N08800 alloy. The subject tube failure involved a through-wall crack that occurred as stress corrosion cracking. Residual stresses in the tube, created from forming of the tube at the time of manufacturing, combined with flow-induced stresses experienced in service as the steam generator operated, resulted in the formation of longitudinal cracking. The cracking formed and extended gradually into and through the tube wall, influenced by corrosion products in the cracks until the failure occurred. Additions of solutions used in boiler water treatment practices potentially induced corrosive substances into the tube. It is suggested that the tubes, especially the lower ones, of the OTSG are not located in a confined space.
Broad and potent neutralizing antibodies are elicited in vaccinated individuals following Delta/BA.1 breakthrough infection
Authors: Seow Jeffrey , Shalim Zayed A. , Graham Carl , Kimuda Simon , Pillai Aswin , Lechmere Thomas , Kurshan Ashwini , Khimji Atika M. , Snell Luke B. , Nebbia Gaia , Mant Christine , Waters Anele , Fox Julie , Malim Michael H. , Doores Katie J. 
Published: September 2023

ABSTRACT
Despite the success of COVID-19 vaccines in preventing infection and/or severe disease, there has been an increase in SARS-CoV-2 infections in vaccinated individuals owing to the waning vaccine-derived immunity, and the emergence of new variants which encode escape mutations in Spike. Following breakthrough infection in vaccinated individuals, an increase in neutralization breadth has been observed in sera/plasma. However, how exposure to a heterologous Spike broadens the neutralizing response at the monoclonal antibody (mAb) level is not fully understood. Through isolation of 119 mAbs from three individuals receiving two doses of BNT162b2 vaccine before becoming Delta or Omicron/BA.1 infected, we show that serum breadth occurs due to the presence of somatically mutated mAbs with broad neutralization activity indicative of re-activation and maturation of B cells generated through previous COVID-19 vaccination. Isolated mAbs frequently show reduced neutralization of current circulating variants including BA.2.75.2, XBB, XBB.1.5, and BQ.1.1 confirming continuous selective pressure on Spike to evolve and evade neutralization. However, isolation of mAbs that display effective cross-neutralization against all variants indicates the presence of conserved epitopes on the receptor binding domain and a lesser extent the N-terminal domain. These findings have implications for the selection of Spike antigens for next-generation COVID-19 vaccines.

IMPORTANCE
With the emergence of SARS-CoV-2 viral variants, there has been an increase in infections in vaccinated individuals. Here, we isolated monoclonal antibodies (mAbs) from individuals experiencing a breakthrough infection (Delta or BA.1) to determine how exposure to a heterologous Spike broadens the neutralizing antibody response at the monoclonal level. All mAbs isolated had reactivity to the Spike of the vaccine and infection variant. While many mAbs showed reduced neutralization of current circulating variants, we identified mAbs with broad and potent neutralization of BA.2.75.2, XBB, XBB.1.5, and BQ.1.1 indicating the presence of conserved epitopes on Spike. These results indicate that variant-based vaccine boosters have the potential to broaden the vaccine response.
GBS hyaluronidase mediates immune suppression in a TLR2/4- and IL-10-dependent manner during pregnancy-associated infection
Authors: Coleman Michelle , Orvis Austyn , Brokaw Alyssa , Furuta Anna , Sharma Kavita , Quach Phoenicia , Bhullar Avneet , Sanghavi Rhea , Nguyen Shayla , Sweeney Erin , Seepersaud Ravin , Armistead Blair , Adams Waldorf Kristina M. , Rajagopal Lakshmi 
Published: September 2023

ABSTRACT

Bacterial infections remain a significant cause of adverse pregnancy outcomes. Ascending infection of group B streptococcus (GBS) or
Streptococcus agalactiae
from the lower genital tract to the amniotic cavity leads to fetal injury, preterm births, or stillbirths. Factors increasing the invasive potential of bacteria at the maternal-fetal interface are poorly understood. Previous studies have indicated that the GBS hyaluronidase (HylB) can enhance systemic infection by breaking down host hyaluronan into disaccharides that dampen protective TLR2 and TLR4 signaling. Here, we examined the importance of hyaluronan receptors such as TLR2, TLR4, and CD44 in defense against GBS infections during pregnancy. While HylB promoted ascending GBS infection in wild-type (WT) and CD44-deficient mice, surprisingly, mice lacking both TLR2 and TLR4 (TLR2/4) were able to curtail these infections. Interleukin-10 (IL-10) and IL-10-expressing macrophages were significantly increased in the uterine tissues of WT mice during infection with HylB-proficient GBS compared with those of TLR2/4-deficient mice, and this likely promotes immune suppression and GBS dissemination. Consistent with these observations, pregnant IL-10-deficient mice exhibited diminished GBS ascension and dissemination. Similarly, the administration of a blocking antibody against the IL-10 receptor (IL-10R) in WT mice diminished ascending GBS infection. Collectively, these observations indicate that HylB promotes immune suppression in a TLR2/4- and IL-10-dependent manner to enhance the invasive potential of GBS during pregnancy-associated infections.

IMPORTANCE
Bacteria such as GBS can cause infections during pregnancy leading to preterm births, stillbirths, and neonatal infections. The interaction between host and bacterial factors during infections in the placenta is not fully understood. GBS secretes a hyaluronidase enzyme that is thought to digest host hyaluronan into immunosuppressive disaccharides that dampen TLR2/4 signaling, leading to increased bacterial dissemination and adverse outcomes. In this study, we show that GBS HylB mediates immune suppression and promotes bacterial infection during pregnancy that requires TLR2, TLR4, and IL-10. Understanding the interaction between host and bacterial factors can inform future therapeutic strategies to mitigate GBS infections.
Coding-complete genome of human alphaherpesvirus 1 isolated from a case of fulminant hepatitis
Authors: Viljoen Natalie , Burt Felicity , Weyer Jacqueline 
Published: September 2023

ABSTRACT
We report the coding-complete genome sequence of human alphaherpesvirus 1 (HHV1) isolated from a previously healthy 64-year-old male with fulminant hepatitis, a rare presentation of a common viral agent. The sequence is highly similar to previously described HHV1 sequences. Additional sequence data for fulminant hepatitis cases are required.
A high-throughput structural system biology approach to increase structure representation of proteins from
Clostridioides difficile
Authors: Rosas-Lemus Monica , Dey Supratim , Minasov George , Tan Kemin , Anderson Spencer M. , Brunzelle Joseph , Nocadello Salvatore , Shabalin Ivan , Filippova Ekaterina , Halavaty Andrei , Kim Youngchang , Maltseva Natalia , Osipiuk Jerzy , Minor Wladek , Joachimiak Andrzej , Savchenko Alexei , Anderson Wayne F. , Satchell Karla J. F. ,   Center for Structural Biology of Infectious Diseases team members
Published: September 2023

ABSTRACT

Clostridioides difficile
causes life-threatening gastrointestinal infections. It is a high-risk pathogen due to a lack of effective treatments, antimicrobial resistance, and a poorly conserved genomic core. Herein, we report 30 X-ray structures from a structure genomics pipeline spanning 13 years, representing 10.2% of the X-ray structures for this important pathogen.
Whole-genome sequence of
Paenibacillus
sp.
,
isolated from soil, Fort Collins, Colorado, USA
Authors: Kiehl Paris M. , Cagle Shelby M. , Kinkel Traci L. , Stenglein Mark D. 
Published: September 2023

ABSTRACT

A whole genome sequence of a
Paenibacillus
sp. bacterium isolated from soil in Fort Collins, Colorado was obtained. This bacterium was of particular interest due to its antibiotic potential against Gram-positive pathogen surrogates.
Isolating and characterizing cluster AB Mycobacteriophage NoShow, which encodes lysis proteins shared with cluster H2 phages
Authors: Niblock Danielle J. , Winkler Anne R. , Curtin Caroline E. , Kokinda Jacqui F. , Danker Walter A. , Llorente Fernandez Ignacio , Smith Ava R. , Ali Asad , Cruz Gabrielle G. , Givvines Leya C. , Lee-Soety Julia Y. 
Published: September 2023

ABSTRACT

We present here Mycobacteriophage NoShow, isolated from a soil sample collected on the Maguire Campus of Saint Joseph’s University in Merion Station, Pennsylvania. Even though NoShow’s 52,825 bp genome is most similar to phages in cluster AB, its
lysA
and
lysB
genes are most similar to phages in cluster H2.
Testing the contribution of dispersal to microbial succession following a wildfire
Authors: Barbour Kristin M. , Weihe Claudia , Walters Kendra E. , Martiny Jennifer B. H. 
Published: September 2023

ABSTRACT
Given increased wildfire activity, there is growing interest in understanding the drivers of microbial succession after fire. Dispersal may be especially important to post-fire succession as biotic communities can be more susceptible to invasion following a disturbance. Here, we experimentally manipulated dispersal into disturbed leaf litter communities collected following a wildfire and tracked bacterial and fungal dispersal assemblages over time. We show that the identity and source of microbes immigrating into the soil surface post-fire change across time with seasonal shifts and the reemergence of aboveground vegetation. Further, dispersal significantly contributed to the reassembly of leaf litter microbial communities after the fire, producing an increasingly distinct assembly trajectory. The effect of dispersal on α-diversity and β-diversity was ecosystem dependent but, unexpectedly, influenced bacterial and fungal communities in a similar manner within ecosystems. Collectively, these results demonstrate that dispersal explicitly alters the course of microbial community succession following a wildfire and may impact bacteria and fungi in parallel ways, despite differing in traits expected to alter dispersal patterns.

IMPORTANCE
Identifying the mechanisms underlying microbial community succession is necessary for predicting how microbial communities, and their functioning, will respond to future environmental change. Dispersal is one mechanism expected to affect microbial succession, yet the difficult nature of manipulating microorganisms in the environment has limited our understanding of its contribution. Using a dispersal exclusion experiment, this study isolates the specific effect of environmental dispersal on bacterial and fungal community assembly over time following a wildfire. The work demonstrates the potential to quantify dispersal impacts on soil microbial communities over time and test how dispersal might further interact with other assembly processes in response to environmental change.
The association between BMI and serum uric acid is partially mediated by gut microbiota
Authors: Duan Zhuo , Fu Jingxiang , Zhang Feng , Cai Yijia , Wu Guangyan , Ma Wenjun , Zhou Hongwei , He Yan 
Published: September 2023

ABSTRACT

Obesity is a risk factor for the development of hyperuricemia, both of which were related to gut microbiota. However, whether alterations in the gut microbiota lie in the pathways mediating obesity’s effects on hyperuricemia is less clear. Body mass index (BMI) and serum uric acid (SUA) were separately important indicators of obesity and hyperuricemia. Our study aims to investigate whether BMI-related gut microbiota characteristics would mediate the association between BMI and SUA levels. A total of 6,280 participants from Guangdong Gut Microbiome Project were included in this study. Stool samples were collected for 16S rRNA gene sequencing. The results revealed that BMI was significantly and positively associated with SUA. Meanwhile, BMI was significantly associated with the abundance of 102 gut microbial genera, 16 of which were also significantly associated with SUA. The mediation analysis revealed that the association between BMI and SUA was partially mediated by the abundance of
Proteobacteria
(proportion mediated: 0.94%,
P
< 0.05). At the genus level, 25 bacterial genera, including
Ralstonia, Oscillospira, Faecalibacterium
, etc., could also partially mediate the association of BMI with SUA (the highest proportion is mediated by
Ralstonia
, proportion mediated: 2.76%,
P
< 0.05). This study provided evidence for the associations among BMI, gut microbiota, and SUA, and the mediation analysis suggested that the association of BMI with SUA was partially mediated by the gut microbiota.

IMPORTANCE
Using 16S rRNA sequencing analysis, local interpretable machine learning technique analysis and mediation analysis were used to explore the association between BMI with SUA, and the mediating effects of gut microbial dysbiosis in the association were investigated.
Factors impacting the regulation of
nos
gene expression in
Staphylococcus aureus
Authors: Brandwein Jessica N. , Sculthorpe Tiffany S. , Ridder Miranda J. , Bose Jeffrey L. , Rice Kelly C. 
Published: September 2023

ABSTRACT

Staphylococcus aureus
nitric oxide synthase (saNOS) contributes to oxidative stress resistance, antibiotic tolerance, virulence, and modulation of aerobic and nitrate-based cellular respiration. Despite its involvement in these essential processes, the genetic regulation of
nos
expression has not been well characterized. 5′ rapid amplification of cDNA ends on
nos
RNA isolated from
S. aureus
UAMS-1 (USA200 strain) and AH1263 (USA300 strain) revealed that the
nos
transcriptional start site mapped to an adenine nucleotide in the predicted Shine-Dalgarno site located 11 bp upstream of the
nos
ATG start codon, suggesting that the
nos
transcript may have a leaderless organization or may be subject to processing. The SrrAB two-component system (TCS) was previously identified as a positive regulator of
nos
RNA levels, and experiments using a β-galactosidase reporter plasmid confirmed that SrrAB is a positive regulator of
nos
promoter activity. In addition, the quorum-sensing system Agr was identified as a negative regulator of low-oxygen
nos
expression in UAMS-1, with activity epistatic to SrrAB. Involvement of Agr was strain dependent, as
nos
expression remained unchanged in an AH1263
agr
mutant, which has higher Agr activity compared to UAMS-1. Furthermore,
nos
promoter activity and RNA levels were significantly stronger in AH1263 relative to UAMS-1 during late-exponential low-oxygen growth, when
nos
expression is maximal. Global regulators Rex and MgrA were also implicated as negative regulators of low-oxygen
nos
promoter activity in UAMS-1. Collectively, these results provide new insight into factors that control
nos
expression.

IMPORTANCE

Bacterial nitric oxide synthase (bNOS) has recently emerged in several species as a key player in resistance to stresses commonly encountered during infection. Although
Staphylococcus aureus
(sa)NOS has been suggested to be a promising drug target in
S. aureus
, an obstacle to this in practice is the existence of mammalian NOS, whose oxygenase domain is like bacterial NOS. Increased understanding of the
nos
regulatory network in
S. aureus
could allow targeting of saNOS through its regulators, bypassing the issue of also inhibiting mammalian NOS. Furthermore, the observed strain-dependent differences in
S. aureus nos
regulation presented in this study reinforce the importance of studying bacterial NOS regulation and function at both the strain and species levels.
Water table level controls methanogenic and methanotrophic communities and methane emissions in a
Sphagnum
-dominated peatland
Authors: Tian Wen , Wang Hongmei , Xiang Xing , Loni Prakash C. , Qiu Xuan , Wang Ruicheng , Huang Xianyu , Tuovinen Olli H. 
Published: September 2023

ABSTRACT

Peatlands are important sources of the greenhouse gas methane emissions equipoised by methanogens and methanotrophs. However, knowledge about how microbial functional groups associated with methane production and oxidation respond to water table fluctuations has been limited to date. Here, methane-related microbial communities and the potentials of methane production and oxidation were determined along sectioned peat layers in a subalpine peatland across four
Sphagnum
-dominated sites with different water table levels. Methane fluxes were also monitored at these sites. The results showed that
mcrA
gene copies for methanogens were the highest in the 10- to 15-cm peat layer, which was also characterized by the maximum potential methane production (24.53 ± 1.83 nmol/g/h). Copy numbers of the
pmoA
gene for type Ia and Ib methanotrophs were enriched in the 0–5 cm peat layer with the highest potential methane oxidation (43.09 ± 3.44 nmol/g/h). For the type II methanotrophs, the
pmoA
gene copies were higher in the 10- to 15-cm peat layer. Hydrogenotrophic methanogens and type II methanotrophs dominated the methane functional groups. Deterministic process contributed more to methanogenic and methanotrophic community assemblages in comparison with stochastic process. The level of water table significantly shaped methanogenic and methanotrophic community structures and regulated methane fluxes. Compared with vascular plants,
Sphagnum
mosses significantly reduced the methane emissions in peatlands. Collectively, these findings enhance a comprehensive understanding of the effect of the water table level on methane functional groups, with consequential implications for reducing methane emissions within peatland ecosystems.

IMPORTANCE

The water table level is recognized as a critical factor in regulating methane emissions, which are largely dependent on the balance of methanogens and methanotrophs. Previous studies on peat methane emissions have been mostly focused on spatial-temporal variations and the relationship with meteorological conditions. However, the role of the water table level in methane emissions remains unknown. In this work, four representative microhabitats along a water table gradient in a
Sphagnum
-dominated peatland were sampled to gain an insight into methane functional communities and methane emissions as affected by the water table level. The changes in methane-related microbial community structure and assembly were used to characterize the response to the water table level. This study improves the understanding of the changes in methane-related microbial communities and methane emissions with water table levels in peatlands.