bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laser Powder Bed Fusion Manufactured Hydrostatic Journal Bearings for Turbomachinery: Design and Measurements of Static Load Testing With Air, Water, and Liquid Nitrogen
Authors: Baek Chaeyeon , Jung Hyunsung , Heo Junwon , Kim Kyuman , Ryu Keun 
Published: October 2024

Abstract
Modern turbomachinery demands simplified components and compact shaft support systems. This study introduces novel hydrostatic journal bearings incorporating multiple tilting pads and fluid feeding features, which are manufactured with Direct Metal Laser Melting (DMLM) technology, an advanced laser powder bed fusion manufacturing process. Two test bearings, fabricated by fusing extremely thin layers of Inconel 718 powder, incorporate fluid external feed pressurization features without the need for recesses. One test bearing features unique internal feeding hole configurations, which combine multiple holes with an angled injection feature, while the other test bearing includes distinctive porous layers on the bearing pad surfaces. This paper provides a comprehensive overview of the design, fabrication process, and static load characteristic measurements of these innovative bearings. A simple static load test rig is used to measure the flow rate, temperature, and stiffnesses of the test bearings while supplying compressed air, water, and liquid nitrogen with increasing static loads. The performance of these bearings is compared with counterparts produced using computer numerical control (CNC) machining, a conventional subtractive manufacturing process. In general, the bearings lubricated with liquid nitrogen exhibit a higher load capacity compared to those lubricated with air. This study confirms the static load performance of metal three-dimensional printed hydrostatic journal bearings, marking a significant advancement in the application of additive manufacturing for turbomachinery bearings. The findings offer valuable insights into the potential of additive manufacturing in producing bearings for extreme operating conditions and various lubricants.
Temperature Dependence of Aerated Turbine Lubricating Oil Degradation From a Lab-Scale Test Rig
Authors: Juárez Raquel , Creighton Barry , Petersen Eric L. 
Published: October 2024

Abstract
Operational, efficiency, safety, and economic issues may arise from the formation and accumulation of sludge, varnish, and coke deposits that result from the degradation of engine lubricants through oxidation or thermal breakdown processes. Having a good understanding of the limits of lubricant performance may be useful in determining the best way to protect the engines. To this end, experiments were conducted using Mobil DTE 732, a turbine lubricant, that is aerated using a coarse gas dispersion tube. The oil then flows through a heated test section with a known axial temperature distribution. The inlet and outlet bulk oil temperature measurements are collected and used to determine the amount of time required for deposit formation and buildup. The induction times were determined for various surface temperatures, up to 236 °C. It was found that increased temperatures shortened induction times, and exposure to oxygen increased the rate at which deposits accumulate, but the nature of the deposits, soft and easily removed, was different from those formed during higher-temperature experiments completed in an inert environment in previous studies. Oil samples collected during the test were analyzed with Fourier transform infrared (FTIR) spectroscopy, with no significant changes detected.
Impact of porin deficiency on the synergistic potential of colistin in combination with β-lactam/β-lactamase inhibitors against ESBL- and carbapenemase-producing
Klebsiella pneumoniae
Authors: Allander Lisa , Vickberg Karin , Fermér Elin , Söderhäll Thomas , Sandegren Linus , Lagerbäck Pernilla , Tängdén Thomas 
Published: October 2024

ABSTRACT

Combinations of colistin and β-lactam/β-lactamase inhibitors (BLBLIs) have shown
in vitro
synergy against β-lactamase-producing strains. However, data are limited and conflicting, potentially attributed to variations among the examined strains. This study investigated whether loss of porins OmpK35 and OmpK36 impacts the synergistic potential of colistin in combination with ceftazidime–avibactam or meropenem–avibactam against β-lactamase-producing
Klebsiella pneumoniae
. Genetically modified strains were constructed by introducing
bla
CTX-M-15
,
bla
KPC-2
, and
bla
OXA-48
chromosomally into
K. pneumoniae
ATCC 35657, in which the major porin-encoding genes (
ompK35
,
ompK36
) were either intact or knocked out. The
in vitro
activity of colistin in combination with ceftazidime–avibactam or meropenem–avibactam was evaluated by time-lapse microscopy screening and in static time-kill experiments. The deletion of porins in the β-lactamase-producing strains resulted in 2- to 128-fold increases in MICs for the β-lactams and BLBLIs. The activity of avibactam was concentration-dependent, and 4- to 16-fold higher concentrations were required to achieve similar inhibition of the β-lactamases in strains with porin loss. In the screening, synergy was observed for colistin and ceftazidime–avibactam against the CTX-M-15-producing strains and colistin and meropenem–avibactam against the KPC-2- and OXA-48-producing strains. The combination effects were less pronounced in the time-kill experiments, where synergy was rarely detected. No apparent associations were found between the loss of OmpK35 and OmpK36 and combination effects with colistin and BLBLIs, indicating that additional factors determine the synergistic potential of such combinations.
Analogs of the anti-malaria drug mefloquine have broad-spectrum antifungal activity and are efficacious in a model of disseminated
Candida auris
infection
Authors: Guin Soumitra , Montoya Marhiah C. , Wang Xiaoyu , Zarnowski Robert , Andes David R. , Meyers Marvin J. , Williams Noelle S. , Krysan Damian J. 
Published: October 2024

ABSTRACT

Only three classes of antifungal drugs are currently in clinical use. Here, we report that derivatives of the malarial drug mefloquine have broad-spectrum antifungal activity including difficult-to-treat molds and endemic fungi. Pharmacokinetic and efficacy studies of NSC-4377 indicate that it penetrates the central nervous system and is active against
Candida auris in vivo
. These data strongly support the further development of mefloquine analogs as a potentially new class of antifungal molecules.
Persistent bloodstream infection in children: examining the role for repeat blood cultures
Authors: Puthawala Christine M. , Feinn Richard S. , Rivera-Viñas José , Lee Hanna , Murray Thomas S. , Peaper David R. 
Published: October 2024

ABSTRACT

Repeat blood cultures are common in children after an initial positive culture. However, in contrast to adults, there are little data to help guide clinicians when a repeat culture is necessary to assess for persistent bacteremia. This study identifies factors associated with persistent bloodstream infections (BSI) in children to inform diagnostic stewardship. This cross-sectional study of children less than 18 years with at least one positive blood culture over a 5-year period utilized a generalized linear equation model to predict patient and microbial factors associated with persistent BSI defined as a positive blood culture with the same organism >48 hours after the index culture. Four hundred and five patients had 502 positive blood cultures yielding 556 organisms. Sixty-seven (13.2%) cultures were persistently positive. Anaerobic organisms (0/37) and
Streptococcus
species (0/104) were never recovered from repeat cultures.
Staphylococcus aureus
(OR 9.45, CI 5.15–17.35) and yeast (OR 78.18, CI 9.45–646.6) were statistically associated with persistent BSI. Patients with prior positive cultures (OR 1.44, CI 1.12–1.84) or a central venous catheter (OR 2.20, 95% CI 1.04–3.92) were also at risk for persistence. Immune dysfunction and elevated inflammatory markers at the time of the index blood culture were not significantly associated with persistence. Yeast or
S. aureus
were associated with persistent BSI, while anaerobes and
Streptococcus
species were never persistent. Patient characteristics at the time of blood draw did not predict persistence other than having previous positive blood cultures or a central venous catheter. These data can inform when repeat blood cultures have clinical value and reduce the risk of unnecessary blood draws in children.

IMPORTANCE
We identify factors associated with bloodstream infection persistence in children. Our findings can help guide blood culture stewardship efforts in pediatric patients, especially in light of blood culture supply shortages.
The changing roles of scientific journals
Authors: Casadevall Arturo , Clark Lorraine F. , Fang Ferric C. 
Published: October 2024

ABSTRACT

After centuries of relative stability, the scientific publishing world has undergone tremendous disruption and change during the first decades of the 21st century. The causes for disruption can be traced to the information revolution, which brought such benefits as rapid publication, greater connectivity, and ready access to large databases, along with less desirable practices including image manipulation, plagiarism, and other ethical transgressions. The information revolution has driven the proliferation of journals, expansion of for-profit academic publishing, and empowerment of the open-access movement, each of which has exerted new financial pressures on traditional publishing models. As journals became the focal point for ethical concerns in science, they have adapted by increasing the scope of their duties, which now include archiving of data, enforcement of good practices, establishment of standards for rigor, and training the next generation of reviewers and editors. Here, we consider the seismic changes occurring in scientific publishing and place them into the context of a rapidly changing landscape of scientific and publishing norms.
From soil to clinic: current advances in understanding
Coccidioides
and coccidioidomycosis
Authors: Jackson Katrina M. , Teixeira Marcus de Melo , Barker Bridget M. 
Published: October 2024

SUMMARY

Coccidioides immitis
and
Coccidioides posadasii
are fungal pathogens that cause systemic mycoses and are prevalent in arid regions in the Americas. While
C. immitis
mainly occurs in California and Washington,
C. posadasii
is widely distributed across North and South America. Both species induce coccidioidomycosis (San Joaquin Valley fever or, more commonly, Valley fever), with reported cases surging in the United States, notably in California and Arizona. Moreover, cases in Argentina, Brazil, and Mexico are on the rise. Climate change and environmental alterations conducive to
Coccidioides
spp. proliferation have been recently explored. Diagnostic challenges contribute to delayed treatment initiation, compounded by limited therapeutic options. Although antifungal drugs are often effective treatments, some patients do not respond to current therapies, underscoring the urgent need for a vaccine, particularly for vulnerable populations over 60 years old relocating to endemic areas. Despite recent progress, gaps persist in the understanding of
Coccidioides
ecology, host immune responses, and vaccine development. This review synthesizes recent research advancements in
Coccidioides
ecology, genomics, and immune responses, emphasizing ongoing efforts to develop a human vaccine.
Antibiotic resistance and draft genome profiles of 10
Streptococcus pneumoniae
and 3
Streptococcus pseudopneumoniae
strains isolated from the nasopharynx of people living with human immunodeficiency virus in Ghana
Authors: Ativi Lawrencia Ami Emefa , Adusei-Poku Mildred , Boateng William , Owusu-Nyantantakyi Christian , Kwesi Danso Justice , Oclu Agnes , Bortey Alfred , Rabbi Amuasi Grebstad , Kofi Adu Tabi Blessing , Paintsil Elijah , Torpey Kwasi , Dzifa Dayie Nicholas , Egyir Beverly 
Published: October 2024

ABSTRACT

Genomic data on clinically important bacteria species such as
Streptococcus pneumoniae
and
Streptococcus pseudopneumoniae
from low- and middle-income countries, including Ghana, are scarce. In this study, we provide data on antimicrobial resistance (AMR) and whole-genome profiles of a collection of streptococci species to support AMR surveillance efforts in the country.
Complete genome sequences of eight
Pasteurella multocida
isolates representing all lipopolysaccharide outer core loci
Authors: Hashish Amro , Johnson Timothy J. , Ghanem Mostafa , Sato Yuko , Macedo Nubia R. , LeCount Karen J. , El-Gazzar Mohamed 
Published: October 2024

ABSTRACT

Pasteurella multocida
(PM) is a major bacterial pathogen that causes fowl cholera disease in both domestic poultry and wild birds. Here, we report the complete genome sequences of eight PM isolates representing all known lipopolysaccharide outer core loci, which are phenotypically expressed as 16 known PM serotypes.
Diel metatranscriptomes capture cyanobacteria-dominated Lake Erie community response to episodic events
Authors: Zepernick Brittany N. , Boegehold Anna G. , Kiledal E. Anders , Chase Emily E. , Hart Lauren N. , Houghton Katelyn A. , Martin Robbie M. , Williams Paige A. , Johnson Emma C. , Schofield Paris K. , Cory Rose M. , Chaganti Subba Rao , Godwin Casey M. , Spanbauer Trisha L. , Dick Gregory J. , Errera Reagan M. , Wilhelm Steven W. 
Published: October 2024

ABSTRACT

Here, we report on the raw and coassembled metatranscriptomes of 39 Lake Erie surface (1.0 m) water samples collected over a 2-day diel period encompassing episodic weather and bloom events. Preliminary taxonomic annotations and read mappings revealed that
Microcystis
spp. accounted for up to ~47% of the transcriptionally active community.
Pseudomonas aeruginosa
kills
Staphylococcus aureus
in a polyphosphate-dependent manner
Authors: Shah Ritika , Narh Julius Kwesi , Urlaub Magdalena , Jankiewicz Olivia , Johnson Colton , Livingston Barry , Dahl Jan-Ulrik 
Published: October 2024

ABSTRACT

Due to their frequent coexistence in many polymicrobial infections, including in patients with cystic fibrosis or burn/chronic wounds, many studies have investigated the mechanistic details of the interaction between the opportunistic pathogens
Pseudomonas aeruginosa
and
Staphylococcus aureus. P. aeruginosa
rapidly outcompetes
S. aureus
under
in vitro
cocultivation conditions
,
which is mediated by several of
P. aeruginosa
’s virulence factors. Here, we report that polyphosphate (polyP), an efficient stress defense system and virulence factor in
P. aeruginosa
, plays a role in the pathogen’s ability to inhibit and kill
S. aureus
in a contact-independent manner. We show that
P. aeruginosa
cells characterized by low polyP levels are less detrimental to
S. aureus
growth and survival while the Gram-positive pathogen is significantly more compromised by the presence of
P. aeruginosa
cells that produce high levels of polyP. The polyP-dependent phenotype of
P. aeruginosa
-mediated killing of
S. aureus
could at least in part be direct, as polyP was detected in the spent media and causes significant damage to the
S. aureus
cell envelope. However, more likely is that polyP’s effects are indirect through modulating the production of one of
P. aeruginosa’s
virulence factors, pyocyanin. We show that pyocyanin production in
P. aeruginosa
occurs polyP-dependently and harms
S. aureus
through membrane damage and potentially the generation of reactive oxygen species, resulting in the increased expression of antioxidant enzymes. In summary, our study adds a new component to the list of biomolecules that the Gram-negative pathogen
P. aeruginosa
generates to compete with
S. aureus
for resources.

IMPORTANCE

How do interactions between microorganisms shape the course of polymicrobial infections? Previous studies have provided evidence that the two opportunistic pathogens
Pseudomonas aeruginosa
and
Staphylococcus aureus
generate molecules that modulate their interaction with potentially significant impact on disease outcomes. Our study identified the biopolymer polyphosphate (polyP) as a new effector molecule that impacts
P. aeruginosa
’s interaction with
S. aureus
. We show that
P. aeruginosa
kills
S. aureus
in a polyP-dependent manner, which occurs primarily through the polyP-dependent production of the
P. aeruginosa
virulence factor pyocyanin. Our findings add a new role for polyP to an already extensive list of functions. A more in-depth understanding of how polyP influences interspecies interactions is critical, as targeting polyP synthesis in bacteria such as
P. aeruginosa
may have a significant impact on other microorganisms and potentially result in dynamic changes in the microbial composition.
Clinical impact of the use of chronic suppressive antibiotics against recurrent ventricular assist device infections
Authors: Yamamoto Shinya , Okamoto Koh , Kumamaru Hiraku , Saito Makoto , Ito Hiroshi , Yamashita Marie , Kanno Yoshiaki , Ikeda Mahoko , Harada Sohei , Okugwa Shu , Kimura Mitsutoshi , Kinoshita Osamu , Ono Minoru , Tsutsumi Takeya , Moriya Kyoji 
Published: October 2024

ABSTRACT

Ventricular assist device (VAD) infections are frequent causes of hospital readmission. The risk factors and optimal preventive strategies for such, including chronic suppressive antibiotics (CSA), remain uncertain. We performed a single-center, retrospective, observational cohort study assessing continuous flow VAD recipients who underwent implantation between 2008 and 2018 in Japan. From primary VAD infection (VADI), we followed the patients for recurrent infection, defined as relapsing VAD-specific (e.g., localized infections) or VAD-related (e.g., bacteremia) infections requiring hospital readmission. CSA was defined as the use of oral antimicrobial agents continued beyond initial antibiotic use until transplantation, VAD withdrawal, VADI recurrence, or death. Survival analysis was performed to identify risk factors for recurrent infection accounting for competing risks (e.g., deaths and transplants). Among 163 eligible patients, 76 patients had VADIs. The main causative organism in primary VADI was
Staphylococcus aureus
(63%, 48/76). Among them, 41 had recurrent infections, whereas 35 had none during the follow-up period (median, 335 days). Thirty-six patients received CSA for a median of 478 days. Although CSA was associated with a decreased risk of recurrent infection [adjusted sub-distribution hazard ratio (SHR), 0.40; 95% confidence interval (CI), 0.18–0.89;
P =
0.03], this protective effect was observed only after primary VAD-specific infection (SHR, 0.28; 95% CI, 0.12–0.64;
P
< 0.01) but not after VAD-related infection. Surgical procedures during primary VADI were associated with an increased risk (SHR, 2.00; 95% CI, 1.10–3.66;
P
= 0.02). One patient had an adverse drug reaction. CSA may be an effective approach to limit relapsing VADIs following a primary VAD-specific infection with minimal adverse events.

IMPORTANCE
Ventricular assist device infections (VADIs) are a significant complication leading to hospital readmissions. However, the risk factors and optimal preventive strategies for VADI remain unclear. This study investigated the effectiveness of chronic suppressive antibiotic therapy in patients with VADI. We found that the use of chronic suppressive antibiotic therapy was associated with a reduction in the risk of VADI recurrence with few adverse reactions. Our findings suggest the potential benefit of chronic suppressive antibiotics in preventing infections in selected cases. Our findings are relevant for the management of patients with ventricular assist devices awaiting heart transplantation, providing valuable insights for clinical practice.
Ethnic-specific oral glucose tolerance (OGTT) phenotypes in women with hyperglycemia in pregnancy
Authors: Tan Yu Bin , Quah Phaik Ling , Tan Kok Hian 
Published: October 2024

IntroductionEthnic differences associated with oral glucose tolerance test (OGTT) phenotypes is less studied in Southeast Asian ethnicities, especially in women with hyperglycemia in pregnancy (HIP).Research design and methodsWe retrospectively examined 3027 women at KK Women’s and Children’s Hospital in 2019. Of these, 508 (16.8%) women were diagnosed with HIP using the IADPSG (International Association of Diabetes and Pregnancy Study Groups) criteria at 24–28 weeks. OGTT phenotypes were classified into four mutually exclusive groups based on abnormal plasma glucose at (1) 0 hour only; (2) 1 hour only; (3) 2 hour only; (4) ≥2 timepoints (reference). Multinomial logistic regression was used to examine the association between ethnicity and OGTT phenotypes, adjusting for maternal age, parity, and first-trimester body mass index.ResultsOverall HIP prevalence was 16.8%, highest among Indians (20.5%), then Chinese (18.3%) and Malays (14.2%). Indians (relative risk ratio (RRR) 3.05) and Chinese (RRR 2.33) were at higher risk of displaying a fasting-only phenotype compared with Malays. Chinese were at increased risk of displaying a 2-hour postprandial phenotype with an RRR of 2.88 as compared with Malays.ConclusionsUnique OGTT phenotypes exist across ethnic groups among women who developed HIP in a multi-ethnic Asian population.
Clinical and echocardiographic parameters associated with outcomes in patients with moderate secondary mitral regurgitation
Authors: Sarrazyn Camille , Fortuni Federico , Laenens Dorien , Chua Aileen Paula , Lopez Santi Maria Pilar , Myagmardorj Rinchyenkhand , Nabeta Takeru , Meucci Maria Chiara , Singh Gurpreet Kaur , Velders Bart Josephus Johannes , Galloo Xavier , Bax Jeroen Joost , Ajmone Marsan Nina 
Published: October 2024

BackgroundSignificant secondary mitral regurgitation (SMR) is known to be associated with worse prognosis. However, data focusing specifically on moderate SMR and associated risk factors are lacking. In the present study, clinical and echocardiographic parameters associated with outcomes were evaluated in a large cohort of patients with moderate SMR.MethodsPatients with moderate SMR were retrospectively included and stratified by New York Heart Association (NYHA) class and specific aetiology (atrial SMR (aSMR) or ventricular SMR (vSMR)) with a further classification of vSMR based on left ventricular ejection fraction (LVEF) ≥40% or <40%. The primary endpoint was all-cause mortality and the secondary endpoint was the composite of all-cause mortality and heart failure (HF) events.ResultsOf the total 1061 patients with moderate SMR (age 69±11 years, 59% male) included, 854 (80%) were in NYHA class I−II and 207 (20%) were in NYHA class III−IV. Regarding the aetiology, 352 (33%) had aSMR and 709 (67%) had vSMR, of which 329 (46%) had LVEF ≥40% and 380 (54%) had LVEF <40%. During a median follow-up of 82 (IQR 55–115) months, 397 (37%) died and 539 (51%) patients had HF events or died. On multivariable analysis, NYHA class III−IV (HR 1.578; 95% CI 1.244 to 2.002, p<0.001) and SMR aetiology were independently associated with both endpoints. Specifically, compared to aSMR, vSMR with LVEF ≥40% had a HR of 1.528 (95% CI 1.108 to 2.106, p=0.010) and vSMR with LVEF <40% had a HR of 1.960 (95% CI 1.434 to 2.679, p<0.001). To further support these findings, patients were matched for (1) NYHA class and (2) SMR aetiology by propensity scores including age, sex, diabetes, chronic obstructive pulmonary disease, renal function, left atrial volume index, NYHA class (only for SMR aetiology matching), LVEF, SMR aetiology (only for NYHA class matching), tricuspid regurgitation severity and right ventricular pulmonary artery coupling index. After matching, NYHA class and SMR aetiology remained associated with both outcomes (for both: log rank p<0.050).ConclusionIn patients with moderate SMR, distinction in SMR aetiology and assessment of symptoms are important independent determinants of outcome.