bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Validation of an Effective Screening Process for Thermal-Hydraulic Phenomena With Relevance to Thermal Loads in Nuclear Power Plants Piping System
Authors: Rudolph Luciana , Trewin Richard , Buettner Robert , Fuchs Thomas
Published: November 2024

In nuclear power plants (NPP), there is a series of pipe junctions with a main pipe connected to closed-end branch pipe, in which degradation due to high cycle thermal fatigue potentially can occur. The identification of those locations in NPP piping systems is highly important to decide on mitigation activities. Thermal-fatigue cracking due to thermal stresses in a branch pipe occurs at the fluctuating boundary created by the turbulent penetration of hot liquid from the main pipe into the nominally cold liquid of the branch line. The branch flow is nominally stagnant due to, e.g., a closed valve in the branch, but flow can recirculate within the branch. This is a thermal-hydraulic phenomenon also known as the “Farley-Tihange” phenomenon. The proposed screening process consists of two steps: a fast-running thermal-hydraulic tool as a pre-screening step, and a detailed analysis of the three-dimensional flow by means of computational fluid dynamics (CFD) as final step. In the present study, the accuracy and effectiveness of the developed screening tool is evaluated. The results are compared with available experimental data from the open literature, such as vortex penetration depth in the branch pipe. The fast-running thermal-hydraulic tool sorts the junctions into those that are potential risk locations where thermal fatigue is a possibility, and those where thermal fatigue can be conservatively ruled out. The branches identified as potential risks are analyzed in a detailed CFD simulation to generate sufficient information to take further expert decisions, such as installation of a fatigue monitoring system or design changes.
Structural Capacity Estimation of Subsea Flanges Using Various Codes and Standards
Authors: Karpanan Kumarswamy , Kirkemo Finn , Subramanian Kannan
Published: November 2024

High-pressure flanges of varying sizes, starting from 1/2″ are used in subsea oil and gas production equipment such as trees, manifolds, risers, valves, etc. These flanges are designed up to 20 ksi operating pressure with a test pressure of 30 ksi. Additionally, flanges used in subsea applications are exposed to high bending, shear, and torsional loads. API 6A flanges with BX gaskets are commonly used in subsea and surface oil and gas production equipment. API TR 6AF1 and API TR 6AF2 technical reports provide the pressure, bending, and tension capacity of these flanges. The flange capacity is presented as capacity charts. It should be noted that the API flanges are designed to the criteria of API 6A. Along with standard API flanges, subsea equipment also uses non-standard flanges, also known as Other-End Connections (OEC).

In this paper, a subsea API 7 1/16″-15K standard flange design and analysis is presented. This flange is analyzed to design criteria from various codes and standards used in the oil and gas industry such as API 6A, API 6X, API 17D, API17G, API 16A, ASME VIII-2, ASME VIII-3, and NORSOK U-001. These codes and standards allow elastic, elastic perfectly plastic (limit load), and elastic-plastic finite element analysis to estimate the flange capacity. The flange design capacity estimated based on these codes and standards is presented and compared against the existing API 6AF flange capacity. The flange capacity includes functional capacity (leakage and hub separation) and structural capacity (bolt capacity and flange capacity). This paper also discusses the conservatism and limitations in each of these codes and standards for the flange design. The analysis procedures presented in this paper can be used for designing OECs.
A Review of Relief Valves in Unsteady Flow - Behavior, Analysis, and Design
Authors: Dudley Mark , Schreuder Jans , Witte Dylan , Rorabaugh Devin , Lang Scott
Published: November 2024

Pressure relief devices (PRDs) are used to protect system components from high pressures. Appropriately sized devices eliminate these high pressures while relieving a minimal amount of process fluid. As a result, they are frequently found in both incompressible and compressible systems to relieve overpressures. However, relief devices are historically known to be ineffective for handling surge overpressures. While PRD standards and sources simply encourage the avoidance of surge, it is an inevitability within most systems and the interaction between surge and PRDs, both conventional and surge-mitigating, are investigated here within.

This paper discusses the basics of PRD terminology, mathematical PRD models, and PRD computer simulation modeling with associated examples. Basic design principles, guidelines for identifying at-risk-for-surge systems, and relief valve selection criteria for surge mitigation are presented.
Non-Conservative Fracture Toughness Measurements Due to Unintentional Trace Oxygen Impurities in Hydrogen Gas
Authors: Nibur Kevin
Published: November 2024

It is recognized that oxygen gas impurities can inhibit the deleterious effects of hydrogen gas on mechanical properties of steels. Most commonly, the effect of oxygen on hydrogen assisted fatigue has been studied. An increase in the measured hydrogen-assisted fracture toughness has been reported to result from oxygen gas impurities, but few efforts have been made to understand how much oxygen can be present in hydrogen gas without altering measured fracture toughness values. Routine measurements of the post-test oxygen content has revealed various instances where the measured oxygen content was unintentionally higher than expected. This paper will present some of these chance observations in which unintentionally elevated oxygen levels resulted in elevated fracture toughness measurements. Oxygen concentrations as low as 0.1 part per million have been observed to effectively inhibit hydrogen assisted fracture under certain conditions. These observations indicate the extreme importance of understanding and controlling the levels of trace oxygen impurities in hydrogen gas during fracture toughness measurements to avoid anomalously high measurements. Finally, it should be noted that these observations apply only to fracture measurements performed at laboratory test time scales (typically measured in hours); it is not currently understood whether similar trace levels of oxygen will inhibit crack growth in structures operated over operational time scales measured in months to years.
Case Study on a Cracking Failure in UNS N06693 Weld for Steam Generator Applications
Authors: Pickle Tim , Kho Kok-Theng , Penso Jorge , Yu Zhenzhen
Published: November 2024

UNS N06693 is a Ni-base alloy that provides metal dusting corrosion resistance in steam generator pipes with operating temperatures above 500°C. A crack failure occurred in a 6.5mm thick similar weld pipe joint, located at both fusion zone and heat affected zone, after about 10 years in service and 2 months after weld repair in adjacent weld, which warranted an investigation into possible root causes of failure. This study investigates the potential failure mechanisms that may arise during service (such as stress relaxation cracking, stress corrosion cracking, ductility dip cracking, and creep failure) for UNS N06693 in order to understand the observed cracking behavior. In this year, preliminary fractography, metallurgical characterization, thermodynamic and kinetic CALHAD simulations, and investigation into potential contributing factors (e.g., weld procedure specifications (WPS) and post weld heat treatment (PWHT)) to failure have been completed. The fracture surfaces indicate brittle, intergranular failure, such that no shear lips were observed, and radial lines (crack propagation) were primarily observed in weld fusion zone. Metallurgical characterization near the fracture surface is conducted to reveal the contributing factors to failure, such as intermetallic phases (e.g., Cr-rich α-phase) and distribution of carbide particles (e.g., intergranular chromium carbides), that may contribute to reduced cracking and sensitization resistance. Blocky, intergranular Cr-rich precipitates, either Cr-rich α-phase or Cr-rich M23C6., are observed behind secondary cracks. Based on the initial findings, contributing factors for failure considered are increase in tensile residual stresses due to nearby repair field weld and grain boundary embrittlement due to coarse, blocky Cr-rich phase that likely developed during initial PWHT and within the 10-year service window. In the following year, a more in-depth metallurgical characterization, discussion on contributing causes and possible mitigation strategies for improving microstructural stability and performance-based weldability (e.g., weld procedure and PWHT design), and conclusions with root cause analysis will be provided.
Case Study: Lip Seal Retrofit Analysis Using Finite Element Method for Heat Exchanger
Authors: Pasnik Louis , Gu Ming (Forrest) , Seipp Trevor G.
Published: November 2024

A high-pressure heat exchanger channel with integral tubesheet was upgraded from low chrome to austenitic materials, while the shell-side material remained ferritic. Due to concerns with thermal differential radial expansion between the austenitic tubesheet and the ferritic shell-side flange, an Omega-type lip seal design was incorporated, replacing the traditional flat lip seal design.

The finite element method was used in a transient thermal-mechanical and fatigue analysis of the lip seal loop and internal fillet welds. Historic plant operating data from past startups, upsets, and shutdowns was used to define idealized transient fluid temperatures and film coefficients which were applied to the model.

The internal fillet welds connecting the lip seal halves to the flange and tubesheet pairs were found to be limiting. Due to the requirement to reuse the existing ferritic shells, improvements were made to the fatigue life by incorporating groove welds in combination with the fillet welds.
Alloy Effects in Steels for Explosive Containment Vessels
Authors: Mueller Joshua J. , Gibson Joshem , Thrun Melissa
Published: November 2024

Explosive containment vessels (ECVs), such as those utilized to contain the detonation products of explosives during bomb/munition disposal or containment of experiments on explosive devices, are required to be fabricated from high-integrity materials to ensure the safety of people and/or property in the vicinity of the vessel. Candidate materials for ECV construction are desired to exhibit high strength and high toughness to prevent ductile exhaustion and/or brittle failure induced by impulsive loading; a non-trivial requirement given that, generally, materials exhibit poorer toughness with increasing strength. Additionally, vessel manufacturability (e.g. weldability and component thickness) also needs also to be considered when selecting materials for ECVs.

Los Alamos National Laboratory has had success using both A723 and HSLA-100 steel alloys for ECV applications. The present article provides a background on these two alloys and compares them from the perspectives mentioned above. A723 is better suited for thick-section and non-welded applications, whereas HSLA-100 is better suited for thinner (< ∼10 cm) vessel components but also supports welding without post-weld heat treatment. Discussion is included regarding how the effects from the alloy compositions of these two steels enables them to perform in complementary applications. This discussion is extended to current alloy development for ECVs which seeks to improve performance and manufacturability.
Investigating In-Situ Fracture Behaviors of Polymer Pipeline Materials in Hydrogen and Hydrogen-Methane Blended Gas Environments
Authors: Ko Seunghyun , Qiao Yao , Nickerson Ethan , Shin Yongsoon , Han Kee Sung , Kuang Wenbin , Simmons Kevin
Published: November 2024

To reduce carbon emissions, the US natural gas infrastructure is seen as a primary solution for efficiently transporting hydrogen gas. Blending hydrogen gas with natural gas and transporting it across a national infrastructure could save significant infrastructure costs. To properly operate the infrastructure under the new gas system, it is critical to understand material compatibility with hydrogen under various conditions. The Blended Gas CRADA, a Hyblend project, is established to determine the material compatibility of existing natural gas pipes with hydrogen gas.

In this study, we investigate the in-plane fracture behaviors of MDPEMarlex and HDPEGDB exposed to hydrogen and hydrogen-methane blended gas. Single-edge notch bending geometry is used. All tests are executed in-situ with the gas environment. The experimental results show a significant effect of the gas environment on HDPEGDB specimens, reducing 5% (H2) to 42% (Blended gas) of specific fracture energy compared to non-aged specimens. For the MDPEMarlex, the effects of the gas environment have increased the specific fracture energy by 10% (H2) to 15% (Blended gas). Fracture surfaces of the tested samples are observed using an electronic microscope. The in-plane fracture surface of HDPEGDB shows a pronounced dimple fracture pattern after exposure to hydrogen and blended gas. The expanded fracture pattern contributes to lower the specific fracture energy. These observations provide critical information for validating polymer pipeline materials when interact with hydrogen and hydrogen-blend gas.
Research and Development of Three-Dimensional Isolation System for Sodium-Cooled Fast Reactor: Part 8 — Assembly Static Test Results of Three-Dimensional Isolated Device by Bi-Axial Loadings
Authors: Somaki Takahiro , Yukawa Masaki , Fukasawa Tsuyoshi , Hirayama Tomoyuki , Uchita Masato , Miyagawa Takayuki , Okamura Shigeki , Yamamoto Tomohiko , Watakabe Tomoyoshi , Miyazaki Masashi , Fujita Satoshi
Published: November 2024

The authors have been developing the three-dimensional isolation system for the Sodium-cooled Fast Reactor (SFR). The three-dimensional isolation device consists of the laminated rubber bearing performing the horizontal isolation function, four-disc spring units, the sliding elements, strength members such as the horizontal support function, and dampers in the horizontal and vertical directions.

We carried out the half-scaled assembly static tests under several bi-axial severe conditions from seismic design base loads to significantly exceeding seismic design base loads, as shown in Part 7. The test specimen was assembled elements of which the three-dimensional seismic isolation system is composed, but the horizontal and vertical damping devices were not modeled because of the static loading tests.

This paper describes tests results, focusing on the following items.

• Behavior of smooth operation and ensuring the independency of horizontal isolation and vertical isolation performances

• Hypothesis and verification of load transfer mechanism under horizontal and vertical loads superposition

• Effect of reinforcing plates on the loading force reduction of horizontal support function

• Conditions of the specimen after tests and discussion
Residual Stresses in Layered Pressure Vessel Nozzles
Authors: Brust Frederick W.
Published: November 2024

The National Aeronautics and Space Administration (NASA) has hundreds of non-code layered pressure vessel (LPV) tanks that hold various gases at pressure scattered across their various space centers across the US. Many of the NASA tanks were fabricated in the 1950s and 1960s and are still in use. An agency wide effort is in progress to assess the fitness for continued service of these vessels because vessel replacements costs are high. Layered tanks typically consist of an inner liner/shell (often about 12.5 mm thick) with different layers of thinner shells surrounding the inner liner each with thickness of about 6.25-mm. The layers serve as crack arrestors for crack growth through the thickness. Most tanks have between 4 and up to 32 layers. Cylindrical layers are welded longitudinally with staggering so that the weld heat affected zones do not overlap. The built-up shells are then circumferentially welded together or welded to a header to complete the tank construction. A prior effort published in the 2022 ASME PVP conference provided results which consider weld residual stress and fracture assessment of some layered pressure vessels.

This paper adds to that effort by presenting results for the nozzle welds that attach to the layered pressure vessels. Weld residual stresses are the most important driver in the fracture response of the tanks because the toughness of the materials is rather low. In this paper, the WRS fields for three different nozzles are presented. The first nozzle considered, labeled V267-270, is a 1,530.35 mm (60.25 inch) inner diameter nozzle welded to a 15-layer tank and summarizes the WRS fields produced. The second nozzle considered here is a nozzle welded to a 1524 mm (60-inch) inner diameter 8-layer tank. The third nozzle weld considered is a 50.8-mm (2-inch) small nozzle weld. Both the residual stress fields are presented along with discussion of the potential fracture response of the nozzle and tank interface. Finally, the effect of repair welds in the nozzles are presented also.
Parametric Evaluation of Fillet Welded Patches With Reinforcing Plug Welds for Pressure Vessels Using Finite Element Analysis
Authors: Alian Ahmed , Moussa Ahmed , Nguyen Luat , Malik Sadath
Published: November 2024

The inspection of the Moderator Purification System Heat Exchanger identified microbiological corrosion at several locations on the shell side. The minimum measured thicknesses at different locations are projected to be lower than the pressure based minimum wall thickness when projected to the targeted end of life of the vessel. To ensure a continuous and safe operation of the heat exchanger until replacement, this work presents a repair strategy of the corroded areas on the shell using fillet welded patches with reinforcing plug welds following the procedure in Article 207 of ASME PCC-2-2022 edition. Plug welds can be engineered to bear a share of up to 30% of the patch plate’s load and must be appropriately positioned to carry their allotted portion of the load. The plug welds serve to decrease the bending moments experienced by the fillet welds, enabling the repair of large defects. ASME PCC-2 provides a wide range for the plug welds geometrical parameters (such as distance from the edge and diameter). In this work, a parametric 3D finite element study is performed to determine the optimized configuration of plug welds that reduces the stresses in the fillet welds. The results show significant reductions in the fillet weld stresses, up to 50%, when the diameter and distance from the patch edge to the plugs are varied within the limits provided by the ASME PCC-2 guidelines.
Aerobic Energy Turnover and Exercise Economy Profile During Race Simulation in a World-Record-Breaking Male Full-Distance Triathlete
Authors: Christensen Peter M.
Published: November 2024

Purpose: To investigate metabolism and exercise economy during prolonged race simulation (>4 h) in a world-class, full-distance triathlete to help guide/adjust strategies for training, nutrition, hydration, and thermoregulation. Methods: Two experimental race-simulation days, designed to mimic the demands of a full-distance triathlon, were executed by a world-class male triathlete (MD; 25 y, body weight 82 kg, 6.2 L·min−1, blood lactate threshold ∼410 W, and 18 km · h−1 in cycling and running) who at the time ranked second in the world. Race simulation was performed 23 and 10 days prior to competing in Challenge Roth 2023, where MD won in a new world record/best time (7:24:40 h:min:s). Both test days lasted ∼4 to 5 hours with physiologic testing every ∼45 to 60 minutes in a “stationary” setting during cycling on a direct-mount trainer (∼320 W) and treadmill running (16 km · h−1), enabling gas exchange measurements ( and respiratory exchange ratio) and other physiologic measurements of interest (ie, core temperature and heart rate). This was combined with “real activity” as repeated loops in an open-air field setting at expected race pace in swimming, biking, and running. Results: was maintained at ∼4.2 L·min−1, with carbohydrates being the dominant fuel for oxidation as respiratory exchange ratio values dropped from ∼1 at the start of cycling to ∼0.85 during running. Cycling economy was stable, whereas a slight impairment in running economy occurred over time. Conclusion: High aerobic energy turnover and stable exercise economy can be maintained in a world-class record-breaking triathlete for prolonged period of time (+4 h), showcasing the importance of both for success in competition.
Sport and Exercise Psychophysiology: From Theory to Practice
Authors: Filho Edson , Bigliassi Marcelo
Published: November 2024

Psychophysiology pertains to the study of the reciprocal and “many to many” relations between the mind and the body. Accordingly, this special issue includes a collection of articles examining psychophysiological mechanisms implicated in the performance and well-being of athletes and exercisers. More specifically, this issue contains a literature review on the effects of heart rate variability biofeedback and athletic performance, as well as two empirical articles on the effects of neurofeedback on myriad psychological variables, such as attentional focus, anxiety, stress, and depression. There is also a paper on the effects of a self-talk intervention on free-throw performance in basketball and somatic reactions and a novel study on the effects of repeated transcranial direct current stimulation on decision making among soccer players. Collectively, the articles included in this issue advance our understanding of how psychophysiological theories and methodologies can inform the development of applied interventions in sport, exercise, and performance psychology.
Neural network-based predictions of antimicrobial resistance phenotypes in multidrug-resistant
Acinetobacter baumannii
from whole genome sequencing and gene expression
Authors: Jia Huiqiong , Li Xinyang , Zhuang Yilu , Wu Yuye , Shi Shasha , Sun Qingyang , He Fang , Liang Shanyan , Wang Jianfeng , Draz Mohamed S. , Xie Xinyou , Zhang Jun , Yang Qing , Ruan Zhi
Published: November 2024

Whole genome sequencing (WGS) potentially represents a rapid approach for antimicrobial resistance genotype-to-phenotype prediction. However, the challenge still exists to predict fully minimum inhibitory concentrations (MICs) and antimicrobial susceptibility phenotypes based on WGS data. This study aimed to establish an artificial intelligence-based computational approach in predicting antimicrobial susceptibilities of multidrug-resistant
Acinetobacter baumannii
from WGS and gene expression data. Antimicrobial susceptibility testing (AST) was performed using the broth microdilution method for 10 antimicrobial agents.
In silico
multilocus sequence typing (MLST), antimicrobial resistance genes, and phylogeny based on cgSNP and cgMLST strategies were analyzed. High-throughput qPCR was performed to measure the expression level of antimicrobial resistance (AMR) genes. Most isolates exhibited a high level of resistance to most of the tested antimicrobial agents, with the majority belonging to the IC2/CC92 lineage. Phylogenetic analysis revealed undetected transmission events or local outbreaks. The percentage agreements between AMR phenotype and genotype ranged from 70.08% to 89.96%, with the coefficient of agreement (κ) extending from 0.025 and 0.881. The prediction of AST employed by deep neural network models achieved an accuracy of up to 98.64% on the testing data set. Additionally, several linear regression models demonstrated high prediction accuracy, reaching up to 86.15% within an error range of one gradient, indicating a linear relationship between certain gene expressions and the corresponding antimicrobial MICs. In conclusion, neural network-based predictions could be used as a tool for the surveillance of antimicrobial resistance in multidrug-resistant
A. baumannii
.
Complete genome sequence of a nitrogen-fixing bacterium,
Klebsiella pasteurii
(formerly
Klebsiella oxytoca
) NG13, a rice rhizosphere isolate
Authors: Yoshidome Daisuke , Hidaka Makoto , Kosono Saori , Nishiyama Makoto
Published: November 2024

Klebsiella oxytoca
NG13 was isolated from the rice rhizosphere in the early 1980s, and its nitrogen-fixing ability has been investigated. For the further advanced research, we sequenced its genome. NG13 contains one chromosome of 5,897,538 bp and no plasmid. NG13 should be classified to
Klebsiella pasteurii
based on ANI.
Antibiotic resistance and serotype distribution of
Shigella
strains in Bangladesh over the period of 2014–2022: evidence from a nationwide hospital-based surveillance for cholera and other diarrheal diseases
Authors: Afrad Mokibul Hassan , Islam Md. Taufiqul , Begum Yasmin Ara , Saifullah Md. , Ahmmed Faisal , Khan Zahid Hasan , Habib Zakir Hossain , Alam Ahmed Nawsher , Shirin Tahmina , Bhuiyan Taufiqur Rahman , Ryan Edward T. , Khan Ashraful Islam , Qadri Firdausi
Published: November 2024

The objective of this study was to assess the prevalence, antimicrobial resistance patterns, and risk factors linked to
Shigella
infections through a nationwide hospital-based diarrheal disease surveillance in Bangladesh. From May 2014 to May 2022, from a systematic sentinel surveillance of
Shigella
infections in over 10 hospitals across Bangladesh, stool specimens were collected from patients with acute watery diarrhea and tested for
Shigella
species by microbiological culture. The susceptibility to antibiotics was tested using the disk diffusion method. Structured questionnaires were used to collect participants’ socioeconomic status and clinical, sanitation, and food history. Out of 24,357 stool specimens, 1.8% were positive for
Shigella
species, with a higher prevalence among males (58%). Children in the 6–17 age group were found to be at the highest risk of
Shigella
infections. The most prevalent serotype was
Shigella flexneri
(79.5%), followed by
Shigella sonnei. S. flexneri
serotype 2a was the most common (63.3%) among all
Shigella
serotypes. Antibiotic susceptibility testing showed over 99% of isolates resistant or with intermediate susceptibility to one of the seven antibiotics tested. About 96% of
S. flexneri
and all
S. sonnei
isolates demonstrated resistance to at least one quinolone class of antibiotics, particularly ciprofloxacin or nalidixic acid.
S. sonnei
showed higher antibiotic resistance and multidrug resistance compared to
S. flexneri
. The high level of resistance to ciprofloxacin highlights the need for more prudent use of this antibiotic and improved hygiene and sanitation. The study emphasized the importance of regular monitoring of drug resistance to effectively manage
Shigella
infections. These findings may provide the epidemiological evidence for conducting future appropriate
Shigella
vaccine clinical trials in Bangladesh.

IMPORTANCE

This nationwide study in Bangladesh assessed
Shigella
infections from 2014 to 2022 from clinical samples.
S. flexneri
was predominant, with concerning antibiotic resistance, notably to ciprofloxacin and nalidixic acid in over 96% of isolates. This emphasizes the urgency of prudent antibiotic use and improved hygiene. The findings provide crucial antimicrobial resistance patterns of
Shigella
species, highlighting the need for ongoing resistance monitoring and potentially informing future vaccine trials.
Identification and biological characteristics of
Fusarium tobaccum
sp. nov., a novel species causing tobacco root rot in Jilin Province, China
Authors: Xie Zhao , Gao Chong , Zhang Xiaoyan , Du Mengzhu , Wang Jun , Wang Xue , Lu Baohui , Chen Changqing , Yang Lina , Zhang Yanjing , Gao Jie
Published: November 2024

Fusarium wilt of tobacco (FWT), caused by
Fusarium
spp., has emerged as a severe threat to tobacco production in China. In all, 132 isolates of
Fusarium
were isolated from tobacco and pathogenic to tobacco-causing FWT in Jilin Province, China. In this study, we identified 7 of 132 isolates as a novel species
Fusarium tobaccum
sp. nov. Zhao Xie & Jie Gao, using multi-gene phylogenetic analyses of translation elongation factor (
tef1
), β-tubulin (
tub2
), calmodulin (
cmdA
), and RNA polymerase II second largest subunit (
rpb2
) genes, along with subtle morphological differences. Isolates of
F. tobaccum
sp. nov. were clustered in a distinct branch in the maximum parsimony phylogenetic tree generated from the sequences of
tef1-rpb2-tub2-cmdA
and can be distinguished from closely related species
F. cugenangense
,
F. callistephi
, and
F. elaeidis
. The morphological characteristics of
F. tobaccum
sp. nov. are distinct from other
Fusarium
species.
F. tobaccum
sp. nov. exhibits abundant aerial mycelia and pigment production on potato dextrose agar (PDA), microconidia with 0–1 septa, and macroconidia with 2–5 septa on carnation leaf-piece agar (CLA), and produces abundant chlamydospores on Spezieller Nährstoffarmer agar (SNA) and CLA. The mycelia of
F. tobaccum
exhibited optimal growth at a pH of 7.1 and a temperature of 23.6°C. Sucrose and NaNO
3
significantly promoted the mycelial growth of
F. tobaccum
. PD medium was optimal for total sporulation. However, the sporulation ratios of the macrospores of
F. tobaccum
in PD, SN, and CMC were relatively low (0.48%, 2.51%, and 2.16%, respectively). These findings provided valuable insights into the morphological and biological characteristics of
F. tobaccum
.

IMPORTANCE

Fusarium
wilt of tobacco (FWT) is a prevalent issue in tobacco-growing regions globally, leading to significant losses in yield and quality. This study identified
F. tobaccum
sp. nov., a novel species of
Fusarium
causing FWT in China. The identification was based on multi-gene phylogenetic analyses and morphological characteristics. The effects of temperature, pH, carbon source, nitrogen source, medium, and light on the mycelial growth of
F. tobaccum
sp. nov. were determined. These findings might contribute to future research on the pathogenic mechanisms of this novel species and the development of strategies to control FWT.
Shifts in bacterial community composition during symbiotic seed germination of a terrestrial orchid and effects on protocorm development
Authors: Zhao Zeyu , Yang Luna , Wang Yaoyao , Qian Xin , Ding Gang , Jacquemyn Hans , Xing Xiaoke
Published: November 2024

Fungi and bacteria often occupy very similar niches; they interact closely with each other, and bacteria can provide direct or indirect benefits to plants that form mutualistic interactions with fungi. In orchids, successful seed germination largely depends on compatible mycorrhizal fungi, but whether and how bacteria contribute to seed germination and protocorm development remains largely unknown. Here, we performed field and laboratory experiments to assess the potential role of bacteria in mediating seed germination and protocorm development in the terrestrial orchid
Gymnadenia conopsea
. Our results suggested that bacterial and fungal communities differ between developmental stages in the germination process. The diversity of bacterial and fungal communities and their interaction network in germinating seeds (Stage 1) differed significantly from those in later developmental stages (Stages 2–5).
Pseudomonas
gradually became the dominant bacterial group as the protocorms matured and showed a positive association with Ceratobasidiaceae fungi. Seed germination tests
in vitro
demonstrated that co-inoculation of
Ceratobasidium
sp. GS2 with
Pseudomonas
isolates significantly improved protocorm growth and development, suggesting that the observed increase in
Pseudomonas
abundance during protocorm development directly or indirectly improves the growth of germinating seeds. Overall, our findings indicate that bacteria may exert non-negligible effects on seed germination of orchids and, therefore, offer valuable perspectives for future strategies for conservation and cultivating orchid species.

IMPORTANCE

It is well known that orchid seeds depend on mycorrhizal fungi to supply the necessary nutrients that support germination in natural environments. Apart from fungi, bacteria may also be involved in the germination process of orchid seeds, but so far, their role has not been intensively studied. This research provides evidence that bacterial community composition changes during seed germination of the terrestrial orchid
Gymnadenia conopsea
. Interestingly,
in vitro
experiments showed that
Pseudomonas
spp., which were the most dominant bacteria in the later germination stages, improved protocorm growth. These results suggest that bacteria contribute to the germination of orchid seeds, which may open new perspectives to apply bacteria as a biofertilizer in the introduction and restoration of
G
.
conopsea
populations.
Short-term weight variability in infants and toddlers: an observational study
Authors: Wright Charlotte Margaret , Hope-McGill Ford , Sivakanthan Harshine , Cole Tim J
Published: November 2024

Aims

To explore short-term weight variability in young children; (1) how it relates to expected weight gain and (2) how it is affected by age, time of day and dietary intakes and outputs.

Methods

Twenty healthy infants aged 2–10 months and 21 healthy toddlers aged 12–35 months were weighed at home by their parents six times over 3 days. The toddlers’ parents also recorded whether they had eaten, drunk, urinated or passed stool in the previous 2 hours. The primary outcome was ‘noise’: the within-subject weight SD pooled separately for infants and toddlers, compared with their expected weight gain over 4 or 8 weeks. Analysis by successive pairs of weights was used to assess the extent of short-term weight gain and loss associated with time of day and eating, drinking and excretion.

Results

In infants, noise (117 g) was much less than the expected weight gain over 4 weeks (280–1040 g) but in toddlers, noise (313 g) was higher than the expected gain over 4 weeks (180–230 g) and around three-quarters the expected gain over 8 weeks (359–476 g). In toddlers, weight tended to fall overnight and rise by day, and recent eating and passage of stool were associated with increased weight gain, even after adjustment for time of day.

Conclusions

In toddlers, the recorded weight may be 300 g higher or lower than the underlying weight trajectory, so that their weight gain based on measurements collected fewer than 8 weeks apart will often be misleading.
Hypokalemic periodic paralysis presenting as cardiac arrest
Authors: Joshi Mugdha , Salameh Wael , Vintch Janine , Goodman Elizabeth Leigh
Published: November 2024

Hypokalemic periodic paralysis (HPP) is a channelopathy with a genetic predisposition which may occur in the presence or absence of hyperthyroidism. We present a unique case of severe HPP associated with both Grave’s thyrotoxicosis and pemphigus vulgaris. The patient developed proximal limb weakness after treatment with rituximab. He then subsequently presented with witnessed ventricular fibrillation arrest. Cardiopulmonary resuscitation was initiated in the field and return of spontaneous circulation was achieved. His initial potassium was 1.9 mmol/L with a marked metabolic acidosis.
Anaesthetic management of a breast cancer patient with cardiac tamponade and bilateral vocal cord paralysis
Authors: Ramirez Ariane Ilog , Jose Geraldine Raphaela Bernardo
Published: November 2024

Metastatic breast cancer presenting with both cardiac tamponade and bilateral vocal cord paralysis is rare. We report a case of an elderly patient with breast cancer who had previously undergone right modified radical mastectomy and then presented with cardiac tamponade and recurrent laryngeal nerve paralysis as complications of the malignancy. She underwent right anterior thoracotomy, pleuropericardial window, left tube thoracostomy and tracheostomy under general anaesthesia. Anaesthetic goal was to secure a potentially difficult airway caused by reduced glottic dimensions secondary to bilateral vocal cord paralysis, while simultaneously maintaining preload, systemic vascular resistance and oxygenation, given the presence of cardiac tamponade. This case highlights a rare presentation of advanced breast cancer and emphasises the devastating implications of these conditions for patients, thus warranting further discussion on their anaesthetic management.
Association between RDW-SD and prognosis across glycemic status in patients with dilated cardiomyopathy
Authors: Feng Jiayu , Huang Yani , Huang Liyan , Zhao Xuemei , Li Xinqing , Xin Anran , Wang Chengyi , Zhang Yuhui , Zhang Jian
Published: November 2024

Introduction

The prognostic significance of red cell distribution width-SD (RDW-SD) as a promising inflammatory biomarker in individuals with non-ischemic dilated cardiomyopathy (DCM) and varying glycemic status remains unexplored.

Research design and methods

Patients hospitalized for DCM in Fuwai Hospital from 2006 to 2021 were retrospectively included. The primary outcome encompassed all-cause mortality and heart transplantations. The multivariable Cox regression was used to evaluate the association between RDW-SD and outcomes in the overall DCM population, and among patients with normoglycemia (NG), pre-diabetes mellitus (pre-DM) and DM.

Results

Among 1,102 patients with DCM, the median age was 48 years and 23.5% were women. In the overall DCM cohort, the RDW-SD was independently associated with the primary outcome (adjusted HR 1.29, 95% CI 1.15 to 1.45, p<0.001, per SD increase). When stratifying patients with glycemic status, the RDW-SD exhibited an independent association with outcome in patients with DCM with pre-DM and DM, the adjusted HRs were 1.48 (95% CI 1.21 to 1.79, p<0.001) and 1.30 (95% CI 1.06 to 1.60, p=0.011) per SD increase, respectively. However, in patients with DCM and NG, the prognostic value of RDW-SD was insignificant, with an adjusted HR of 1.20 per SD increase (95% CI: 0.97 to 1.48, p=0.101).

Conclusions

RDW-SD was independently associated with the outcome in patients with DCM with pre-DM and DM, suggesting potential individualized therapeutic targets for this subset of patients with DCM.
Predictors for colectomy in patients with acute severe ulcerative colitis: a systematic review and meta-analysis
Authors: Zheng Jieqi , Fan Zinan , Li Chao , Wang Daiyue , Zhang Shenghong , Chen Rirong
Published: November 2024

Objectives

Acute severe ulcerative colitis (ASUC) poses challenges to patient management owing to its high surgical rate. This study aimed to identify predictors of colectomy in patients with ASUC.

Design

This is a systematic review and meta-analysis.

Data sources

PubMed and Web of Science were searched up to April 2024.

Eligibility criteria

Studies on the predictors of colectomy in adult patients with ASUC were eligible.

Data extraction and synthesis

Two reviewers independently extracted the data using a prespecified data collection sheet. A qualitative synthesis was performed in tabular form. Random-effect meta-analyses were conducted using OR and 95% CI.

Results

Forty-two studies were included in the systematic review. The reported variables can be categorised into biomarkers, auxiliary examination findings, demographic and clinical characteristics, and drug factors. Through meta-analysis, albumin (OR 0.39 (95% CI 0.26 to 0.59) per 1 g/dL increment, I2=0.0%), high C reactive protein level (2.63 (1.53 to 4.52), I2=29.6%), high erythrocyte sedimentation rate level (2.92 (1.39 to 6.14), I2=0.0%), low haemoglobin level (2.08 (1.07 to 4.07), I2=56.4%), fulfilling the Oxford criteria (4.42 (2.85 to 6.84), I2=0.0%), extensive colitis (1.85 (1.24 to 2.78), I2=47.5%), previous steroids (1.75 (1.23 to 2.50), I2=17.7%) or azathioprine (2.25 (1.28 to 3.96), I2=0.0%) use, and sarcopenia (1.90 (1.04 to 3.45), I2=0.0%) were identified as valuable predictors for colectomy within 1 year. The ulcerative colitis endoscopic index of severity (OR 2.41 (95% CI 1.72 to 3.39), I2=1.5%) was the only predictor found to predict colectomy over 1 year.

Conclusion

Identification of these predictors may facilitate risk stratification of patients with ASUC, drive personalised treatment and reduce the need for colectomy.
Private sector tuberculosis care quality during the COVID-19 pandemic: a repeated cross-sectional standardised patients study of adherence to national TB guidelines in urban Nigeria
Authors: Sassi Angelina , Rosapep Lauren , Faleye Bolanle Olusola , Baruwa Elaine , Johns Benjamin , Kafi Md. Abdullah Heel , Huria Lavanya , Aguilera Vasquez Nathaly , Daniels Benjamin , Das Jishnu , Anyaike Chukwuma , Chijioke-Akaniro Obioma , Pai Madhukar , Oga-Omenka Charity
Published: November 2024

Only a third of tuberculosis (TB) cases in Nigeria in 2020 were diagnosed and notified, in part due to low detection and under-reporting from the private health sector. Using a standardised patient (SP) survey approach, we assessed how management of presumptive TB in the private sector aligns with national guidelines and whether this differed from a study conducted before the start of the COVID-19 pandemic. 13 SPs presented a presumptive TB case to 511 private providers in urban areas of Lagos and Kano states in May and June 2021. Private provider case management was compared with national guidelines divided into three main steps: SP questioned about cough duration; sputum collection attempted for TB testing; and non-prescription of anti-TB medications, antibiotics and steroids. SP visits conducted in May–June 2021 were directly compared to SP visits conducted in the same areas in June–July 2019. Overall, 28% of interactions (145 of 511, 95% CI 24.5% to 32.5%) were correctly managed according to Nigerian guidelines, as few providers completed all three necessary steps. Providers in 71% of visits asked about cough duration (362 of 511, 95% CI 66.7% to 74.7%), 35% tested or recommended a sputum test (181 of 511, 95% CI 31.3% to 39.8%) and 79% avoided prescribing or dispensing unnecessary medications (406 of 511, 95% CI 75.6% to 82.8%). COVID-19 related questions were asked in only 2.4% (12 of 511, 95% CI 1.3% to 4.2%) of visits. During the COVID-19 pandemic, few providers completed all steps of the national guidelines. Providers performed better on individual steps, particularly asking about symptoms and avoiding prescription of harmful medications. Comparing visits conducted before and during the COVID-19 pandemic showed that COVID-19 did not significantly change the quality of TB care.
Approaches, enablers and barriers to govern the private sector in health in low- and middle-income countries: a scoping review
Authors: Goodman Catherine , Witter Sophie , Hellowell Mark , Allen Louise , Srinivasan Shuchi , Nixon Swapna , Burney Ayesha , Bhattacharjee Debrupa , Cocozza Anna , Appleford Gabrielle , Thabet Aya , Clarke David
Published: November 2024

Introduction

The private sector plays a substantial role in delivering and financing healthcare in low- and middle-income countries (LMICs). Supporting governments to govern the private sector effectively, and so improve outcomes across the health system, requires an understanding of the evidence base on private health sector governance. This paper reports on a scoping review, which synthesised evidence on the approaches used to govern private sector delivery and financing of healthcare in LMICs, the effectiveness of these approaches and the key enablers and barriers to strengthening governance.

Methods

We undertook a systematic search of databases of published articles and grey literature to identify eligible papers published since 2010, drawing on WHO’s governance definition. Data were extracted into a pretested matrix and analysed using narrative synthesis, structured by WHO’s six governance behaviours and an additional cross-cutting theme on capacities.

Results

107 studies were selected as relevant, covering 101 LMICs. Qualitative methods and document/literature review were predominant. The findings demonstrate the relevance of the WHO governance behaviours, but the lack of robust evidence for approaches to implementing them. Valuable insights from the literature include the need for a clear vision around governance aims; the importance of ensuring that policy dialogue processes are inclusive and transparent, avoiding interest group capture; the benefits of exploiting synergies between governance mechanisms; and the need to develop capacity to enact governance among both public and private actors.

Conclusion

Governance choices shape not just the current health system, but also its future development. Common barriers to effective governance must be addressed in policy design, stakeholder engagement, public and private sector accountability, monitoring and capacity. Achieving this will require in-depth explorations of governance mechanisms and more rigorous documentation of implementation and outcomes in diverse contexts.
Predictors of study dropout in cognitive-behavioural therapy with a trauma focus for post-traumatic stress disorder in adults: An individual participant data meta-analysis
Authors: Wright Simonne , Karyotaki Eirini , Cuijpers Pim , Bisson Jonathan , Papola Davide , Witteveen Anke B , Back Sudie E , Bichescu-Burian Dana , Capezzani Liuva , Cloitre Marylene , Devilly Grant J , Elbert Thomas , Mello Marcelo , Ford Julian D , Grasso Damion , Gamito Pedro , Gray Richard , Haller Moira , Hunt Nigel , Kleber Rolf J , König Julia , Kullack Claire , Laugharne Jonathan , Liebman Rachel , Lee Christopher William , Lely Jeannette , Markowitz John C. , Monson Candice , Nijdam Mirjam J , Norman Sonya B , Olff Miranda , Orang Tahereh Mina , Ostacoli Luca , Paunovic Nenad , Petkova Eva , Resick Patricia , Rosner Rita , Schauer Maggie , Schmitz Joy M , Schnyder Ulrich , Smith Brian N. , Vujanovic Anka A , Zang Yinyin , Duran Érica Panzani , Neto Francisco Lotufo , Seedat Soraya , Sijbrandij Marit
Published: November 2024

Background

Available empirical evidence on participant-level factors associated with dropout from psychotherapies for post-traumatic stress disorder (PTSD) is both limited and inconclusive. More comprehensive understanding of the various factors that contribute to study dropout from cognitive-behavioural therapy with a trauma focus (CBT-TF) is crucial for enhancing treatment outcomes.

Objective

Using an individual participant data meta-analysis (IPD-MA) design, we examined participant-level predictors of study dropout from CBT-TF interventions for PTSD.

Methods

A comprehensive systematic literature search was undertaken to identify randomised controlled trials comparing CBT-TF with waitlist control, treatment-as-usual or another therapy. Academic databases were screened from conception until 11 January 2021. Eligible interventions were required to be individual and in-person delivered. Participants were considered dropouts if they did not complete the post-treatment assessment.

Findings

The systematic literature search identified 81 eligible studies (n=3330). Data were pooled from 25 available CBT-TF studies comprising 823 participants. Overall, 221 (27%) of the 823 dropped out. Of 581 civilians, 133 (23%) dropped out, as did 75 (42%) of 178 military personnel/veterans. Bivariate and multivariate analyses indicated that military personnel/veterans (RR 2.37) had a significantly greater risk of dropout than civilians. Furthermore, the chance of dropping out significantly decreased with advancing age (continuous; RR 0.98).

Conclusions

These findings underscore the risk of premature termination from CBT-TF among younger adults and military veterans/personnel.

Clinical implication

Understanding predictors can inform the development of retention strategies tailored to at-risk subgroups, enhance engagement, improve adherence and yield better treatment outcomes.