bluuebunny/crossref_metadata_2025 huggingface dataset:
Pleiotrophin Prevents H2O2‐Induced Senescence of Dental Pulp Stem Cells
Authors: Liu Chang , Lei Wanzhen , Zhang Lili , Zhang Chen , Gao Runtao , Jin Luyuan
Published: December 2024

Background

Dental pulp stem cells (DPSCs) are widely used in research on dental tissue regeneration and systemic disease treatment. However, the oxidative microenvironment often causes cellular senescence, leading to decreased function. Our previous study demonstrated that pleiotrophin (PTN), a secreted extracellular matrix‐associated protein, could rescue the proliferative capacity and osteogenic differentiation of replicative senescent DPSCs.

Objective

This study aimed to explore the influence and mechanism of PTN on dental pulp stem cells under H2O2‐induced oxidative microenvironment.

Materials and Methods

DPSCs isolated from human third molars were treated with 100 μm H2O2 for 4 h, mimicking the oxidative microenvironment. To investigate the influence of PTN on DPSC under H2O2‐induced oxidative microenvironment, 50 pg/mL PTN was added in the culture medium for 48 h. RT‐qPCR, western blotting, SA‐β‐gal staining, intracellular ROS production and immunofluorescence staining assays were used to analyse the cellular senescence, osteogenic differentiation capacity, oxidative stress conditions and possible mechanism.

Results

H2O2 treatment increased the ratio of SA‐β‐gal‐positive DPSCs and upregulated the senescence‐related gene expression, including P53, P21 and P16. PTN pretreatment downregulated the ratio of SA‐β‐gal‐positive DPSCs and the expression of these genes. Besides, PTN pretreatment partially reversed the H2O2‐induced decreased osteogenic differentiation potential of DPSCs, total antioxidant capacity and Nrf2 and HO‐1 mRNA expression in DPSCs. Western blotting and immunofluorescent staining results indicated that PTN pretreatment enhanced the Nrf2 nuclear translocation under oxidative stress conditions and observable higher fluorescence signals in the nucleus denoted PTN and Nrf2 colocalisation. Western blotting results showed that PTN reversed the decreased expression of p‐AKT in the H2O2−induced oxidative environment. However, the PI3K inhibitor LY294002 blocked the upregulated levels of total Nrf2. Immunofluorescence staining displayed that LY294002 also inhibited the nuclear translocation of Nrf2 which was enhanced under PTN pretreatment.

Conclusions

This study demonstrated that PTN could prevent senescent damage induced by H2O2 on DPSCs, mainly by combining with Nrf2 and enhancing its nuclear translocation.
Astaxanthin Increases Tumor Suppressor Gene Expression and Affects Cellular Biological Behavior in Oral Dysplastic Keratinocytes by Regulating DNA Methylation
Authors: Wang Peiyan , Yu Xiaofei , Sun Pei , Pan Keqing , Sun Jian , Guo Yiqing , Liu Zhaochen , Jiao Mengyu , Deng Jing , Zhang Hui
Published: December 2024

Background

The inactivation of tumor suppressor genes (TSGs) caused by abnormal DNA methylation is confirmed to be widely present in oral potential malignant diseases (OPMDs). Carotenoids like lycopene and astaxanthin can regulate DNA methylation and exert anticancer effects. Therapeutic effect of astaxanthin in OPMDs and oral squamous cell carcinoma (OSCC) models is confirmed, but the relationship between the anti‐cancer ability of astaxanthin and its DNA methylation regulation ability remains unclear.

Methods

Whole‐genome bisulfite sequencing (WGBS) were used to provide biological information associated with DNA methylation. Methylation specific PCR was used to detect the methylation level of specific sites. Related markers were evaluated by qRT‐PCR and western blot. CCK8 assay, cell scratch assay, flow cytometric analysis were performed to investigate the cell viability, migration, cell cycle, and apoptosis after treated with concentrations of astaxanthin.

Results

WGBS revealed that HOXA3 and SOX1 were the TSGs with significant differences in promoter CpG methylation of oral dysplastic keratinocytes (DOK) cells. After treatment with 8 μM astaxanthin, the promoter CpG methylation levels of the TSGs were significantly reduced, resulting in the increase in gene expression. The overall effect of astaxanthin on DOK cells is inhibiting cell viability, reducing cell migration, leading to cell cycle G0/G1 arrest, and promoting apoptosis.

Conclusions

This study confirmed significant differences in DNA methylation patterns among oral normal, dysplastic, and cancerous cells. Astaxanthin can reduce the promoter CpG methylation level of TSGs by reducing DNA methyltransferase 1 protein expression level, upregulating mRNA and protein expression, and subsequently modulating the biological behavior of DOK.
A Network Map of Intracellular Alpha‐Fetoprotein Signalling in Hepatocellular Carcinoma
Authors: Ramakrishnan Krishnapriya , Sanjeev Diya , Rehman Niyas , Raju Rajesh
Published: December 2024

Alpha fetoprotein (AFP) is a glycoprotein of foetal origin belonging to the albumin protein family. Serum AFP is a long‐conceived early‐diagnostic biomarker for HCC with its elevated expression in different liver pathologies ranging from hepatitis viral infections to fibrosis, cirrhosis, and HCC. Beyond their utility as biomarkers, in support of its contribution to these clinical outcomes, the function of AFP as an immune suppressor and inducer of malignant transformation in HCC patients is well reported. Multiple reports show that AFP is secreted by hepatocytes, binds to its cognate receptor, AFP‐receptor (AFPR), and exerts its actions. However, there is only limited information available in this context. There is an urgent need to gather more insight into the AFP signalling pathway and consider it a classical intracellular signalling pathway, among others. AFP is a highly potent intracellular molecule that has the potential to bind to many interactors like PTEN, Caspase, RAR, and so on. It has been shown that cellular AFP and secreted AFP have different roles in HCC pathophysiology, and a comprehensive map of the AFP signalling pathway is warranted for further theranostic applications.
A US‐Based Multi‐Site Pilot to Screen Hepatitis B Surface Antigen‐Positive Patients for Hepatitis D
Authors: Li Maggie , Hunt Bijou , Balani Bindu , Ogedegbe Chinwe , Gordon Peter , Hayden Joshua , Glick Nancy , Chang Anita , Wang Su , Caponi Mitchell , Yarber‐Cambron Lisa , Bhat Sandeep , Ward Tyshea , Suryadevara Madhu
Published: December 2024

Hepatitis D (HDV) is a severe infection with well‐recognised clinical ramifications that remains relatively neglected and underdiagnosed; consequently, the epidemiology of HDV is poorly characterised, both in the United States and globally. In 2022, a pilot project involving eight healthcare institutions was undertaken to ascertain the prevalence of HDV in healthcare institutions with an HBV seropositivity of at least 1%, describe the characteristics of patients testing positive for HDV, and evaluate diagnostic and laboratory processes of HDV screening. From August 2022 to April 2024, a total of 106,693 patients were tested for HBsAg, of whom 65,341 (61.2%) were female and 40,863 (38.3%) were male, with a mean age of 47 years. The overall HBsAg positivity rate was 1.04% (n = 1112). Among the HBsAg+ samples, 645 (58.0%) underwent HDV Ab testing. The HDV Ab positivity rate was 0.81% (n = 9), with 2 cases of HDV RNA positivity (0.18%). The incomplete testing reflects several challenges associated with screening for both HBV and HDV. Further research is necessary to better understand the epidemiology and burden of HDV in the United States and considerations for implementation.
Successful Central Banks Can Afford to Pay Scant Attention to Money
Authors: Francesco Papadia , Leonardo Cadamuro
Published: December 2024

In the last few decades, central bankers and economists have paid little attention to monetary aggregates, in contrast with the experience of the 1970s and the 1980s. Our evidence shows that monetary aggregates lose relevance when central banks maintain low and stable inflation, as has occurred in recent decades. However, to move from unstable to stable inflation, our findings also show that attention to monetary aggregates is needed. Our findings help resolve the long‐standing controversy about the importance of monetary aggregates for the conduct of monetary policy: monetary aggregates are vital to move from unstable to stable inflation but lose relevance once a central bank has consistently reached price stability.
Assessing Compliance: Violations of WHO Code in Breast Milk Substitute Marketing, Ecuador
Authors: Tello Betzabé , Katherine Silva‐Jaramillo , Angélica Tutasi‐Lozada , Rocío Caicedo‐Borrás , María Valencia Luz , Estefanía Rodríguez
Published: December 2024

Breast milk substitute (BMS) marketing significantly influences global infant feeding practices. Ecuador, like many countries, seeks to regulate these promotions under the WHO's International Code of Marketing of Breast‐Milk Substitutes. This cross‐sectional analysis assessed BMS marketing compliance with WHO's Code in Ecuador. Surveys were conducted with mothers (n = 330) and healthcare professionals (n = 66), complemented by observations at health facilities (n = 33) and retail outlets (n = 44). Media monitoring and product labelling evaluations were also conducted. The study revealed widespread exposure to BMS marketing outside health facilities (91.21% of mothers). Promotional activities targeted healthcare professionals, with significant interactions involving free supplies (26.09%) and gifts (21.74%). Retail outlets prominently displayed BMS promotions, often featuring discounts (95%). Compliance with labelling criteria was notably low, particularly concerning nutrition and health claims (39%). TV emerged as the dominant platform for BMS advertising, with 2884 ads aired over 16 h and 24 min, totalling $1,876,915.50 in expenditures. Digital platforms also featured BMS ads, with significant engagement on social media (533,845 interactions). This study reveals widespread violations of the WHO Code in Ecuador, emphasizing the need for stronger regulations and targeted education for healthcare professionals and the public to protect infant health and promote breastfeeding. Despite existing regulations, the pervasive advertising and substantial investment in BMS marketing across various media underscore significant enforcement gaps. To effectively safeguard maternal and child health, Ecuador must fully incorporate and rigorously enforce all Code recommendations within its national legislation.
Ancient Hybridisation Fuelled Diversification in Acropora Corals
Authors: Wu Tianzhen , Xu Alan Ningyuan , Lei Yanli , Song Haijun
Published: December 2024

Introgression is the infiltration or flow of genes from one species to another through hybridisation followed by backcrossing. This may lead to incorrect phylogenetic reconstruction or divergence‐time estimation. Acropora is a dominant genus of reef‐building corals; however, whether this group has an introgression history before their diversification remains unclear, and previous divergence‐time estimates of Acropora have not considered the impact of introgression. In this study, we broke through the limitation of a few genes and a few species and proved the existence of ancient introgression in the evolution of Acropora from whole‐genome protein‐coding sequences. We inferred 21.9% of all triplet loci (homologous loci from three different species) with a history of introgression and a series of introgression events with a genetic material contribution of up to 30.9% before diversification. Furthermore, 7756 nuclear loci were clustered into three groups using a multidimensional scaling algorithm, the heterogeneity of which resulted in different phylogenetic relationships. The diversification time of Acropora was estimated to be middle to late Miocene when we retained only the gene group with the lowest degree of introgression. The collision of Australia with the Pacific arcs and the Southeast Asian margin in the early Miocene, and a series of cooling events in the middle to late Miocene, may provide geographical and climatic conditions for the diversification of Acropora, respectively. Therefore, our results indicate that at the genome‐wide level, ancient introgressive hybridisation may have promoted the radiation evolution of Acropora. Based on our results, the influence of introgression should be taken into account when reconstructing phylogenetic relationships and evaluating divergence time.
Effect of trait anxiety on visual working memory capacity: The role of filtering efficiency
Authors: Yin Mengxin , Wei Huaihuai , Zou Mingxuan , He Yuqing , Hu Hui , Wang Xiuchao
Published: December 2024

Previous research has consistently shown that high trait anxiety (HTA) reduces spatial and verbal working memory capacity. However, its effects on visual working memory (VWM) are inconsistent, and the underlying mechanisms remain unclear. This study investigates the impact of trait anxiety on VWM capacity and the role of filtering efficiency through two experiments. Experiment 1 utilized a change detection task (CDT) with 2–5 colored squares. The results indicated that low trait anxiety (LTA) individuals had significantly higher K scores than individuals with HTA, particularly under high memory load, indicating limitations in VWM capacity within the HTA group. Additionally, the contralateral delay activity (CDA) amplitude in the HTA group stabilized earlier than in the LTA group, further suggesting a deficit in VWM capacity among HTA individuals. Experiment 2 introduced neutral distractors. Under low load conditions, both groups were unaffected by the distractors. However, under high load, the HTA group was susceptible to interference, whereas the LTA group effectively filtered out distractors. CDA patterns revealed that individuals with HTA could filter distractors under low load but not under high load, whereas LTA individuals showed effective filtering under both conditions.
Whether the Indications for Reverse Shoulder Arthroplasty Should Continue to Be Expanded? A Systematic Review and Meta‐Analysis
Authors: Li Huankun , Bao Hangsheng , Yang Zhidong , Hu Baijun , Pan Yaocheng , Wang Yi , Chen Jiayi , Chen Hongjun , Shen Bisheng , Zou Yonggen
Published: December 2024

Background

It is still unclear whether reverse total shoulder arthroplasty (RTSA) has advantages over traditional hemiarthroplasty (HA) and anatomic total shoulder arthroplasty (ATSA) in the treatment of complex shoulder joint diseases. Therefore, this study aims to evaluate the clinical effectiveness of RTSA in the treatment of complex shoulder joint diseases and further determine whether it is necessary to expand the indications of RTSA.

Method

We conducted a systematic search of studies published between January 1, 2012 and May 31, 2023 in PubMed, Embase, and Cochrane databases. The experimental group included patients who underwent primary reverse total shoulder arthroplasty (RTSA), while the control group consisted of patients who underwent primary hemiarthroplasty (HA) or anatomic total shoulder arthroplasty (ATSA). The minimum follow‐up period was 1 year, and a random‐effects model was utilized for data synthesis.

Results

A total of 45 studies were included in the meta‐analysis. Compare to HA, RTSA showed significant advantages in postoperative ASES scores (p = 0.004), forward flexion (p < 0.0001), and abduction (p < 0.0001). Compare to ATSA, RTSA showed significantly lower postoperative Constant scores (p = 0.004), ASES scores (p = 0.001), SST scores (p < 0.0001), forward flexion (p < 0.0001), abduction (p = 0.011), internal rotation (p < 0.0001), and external rotation (p < 0.0001). Further meta regression analysis was conducted, considering factors such as region, age, gender ratio, and follow‐up time, excluding the influence of relevant factors. Overall, RTSA did not demonstrate advantages in postoperative functional scores and range of motion. In terms of complication and revision rates, RTSA had lower rates compared to HA and ATSA, except for the complication rate, where there was no significant difference between RTSA and ATSA (p = 0.521), but statistically significant differences were observed in other measures.

Conclusion

RTSA demonstrates better clinical efficacy compared to HA but is inferior to ATSA. It can be considered for expanding treatment options for elderly patients with 3 or 4‐part proximal humeral fractures, but it is not suitable for treating end‐stage shoulder arthritis and humeral head necrosis. Overall, the decision to use RTSA should be carefully evaluated based on the extent of the patient's rotator cuff injury.
Management of Bone Defects and Complications After Bone Tumor Resection Using Ilizarov Method
Authors: Zheng Kai , Yu Xiu‐Chun , Cai Jinfang , Xu Ming , Cui Haocheng , Chen Qian , Zhang Jing‐Yu
Published: December 2024

Objective

Ilizarov technology is highly effective in addressing complex orthopedic challenges. This study aims to describe our experience with distraction osteogenesis in managing bone tumors in the lower extremity, focusing on composite bone defects and associated complications.

Methods

A retrospective clinical study was conducted to analyze patients with primary bone tumors who underwent distraction osteogenesis using the Ilizarov method from 2010 to 2020. Some young children received epiphyseal distraction and bone transport as part of their sarcoma surgical treatment. Additionally, external fixation, bone transport, or limb lengthening were employed to address complex postoperative complications associated with bone tumors. The clinical outcomes assessed included the patient's general information, the location of bone defects, the length of bone repair, the status of bone healing, and limb function.

Results

Eleven patients were followed up for an average of 66 months (range, 24–132 months). The average length of repaired bone defects was 13 cm (range, 2.5–32 cm). The cohort comprised three females and eight males, with ages at presentation ranging from 6 to 42 years (mean, 18 years). The sites of involvement included the distal femur (n = 4), femoral diaphysis (n = 3), proximal tibia (n = 2), and the distal tibia (n = 2). Nine patients were diagnosed with osteosarcoma, while one presented with Ewing's sarcoma and another with a giant cell tumor of bone. Three young children were successfully treated with epiphyseal stretching; however, one patient experienced treatment failure. Additionally, seven patients underwent external fixation to address complex postoperative complications, including infection, bone defects, and limb shortening. At the last follow‐up, with the exception of one failure, the average Musculoskeletal Tumor Society (MSTS) limb function scores for the remaining 10 patients were 25 (range, 21–30). Three months post‐fixator removal, the Asociación Latinoamericana de Oncología (ASAMI) bone score was rated as excellent in 63.6% (7/11) of patients, whereas the ASAMI function score was excellent in 36.4% (4/11) and good in 54.5% (6/11) of cases.

Conclusion

The Ilizarov method demonstrates some clinical value in the resection and reconstruction of bone tumors, as well as in the management of postoperative complications associated with such tumors.
Goal‐oriented practices in youth mental health and wellbeing settings: A scoping review and thematic analysis of empirical evidence
Authors: Jacob Jenna , Wozney Lori , Oddli Hanne Weie , Duncan Charlie , Chorney Jill , Emberly Debbie , Law Duncan , Clark Sharon , Heien Sofie , Boulos Leah , Cooper Mick
Published: December 2024

Introduction

Goal‐oriented practices involve practitioners working collaboratively with clients to identify, develop and focus on objectives for the therapeutic work. It has been suggested that the key mechanism underpinning goal‐oriented practices with young people is the development of epistemic trust via the foundation of open communication, along with shared decision‐making: including young people in decisions about their care. However, goal‐oriented work in practice is variable in scope and content, with no research consensus on what it entails, the mechanisms of change and reported outcomes.

Method

This research aims to map the extent, range and nature of the evidence‐base for goal‐oriented practices, including gaps, through a synthesis of the available empirical evidence from the past 20 years. A scoping review of 9783 studies published from 2003 onwards was conducted.

Results

In total, 116 studies were identified for inclusion in the review, focusing on goal‐oriented practices specifically related to the mental health and wellbeing of children and young people aged 0–18 (including caregivers as relevant). Alongside presentation of the key elements of the included studies, three themes were developed relating to the features of mental health and wellbeing goal‐oriented practice in the contexts of the studies: Conceptual and Empirical Constructs of Goal‐Oriented Practices, Quality and Making ‘Good’ Goals, and The Socio‐Cultural Contexts of Goal‐Oriented Practice.

Conclusion

Several areas for future research are identified that will build on this evidence, and further understanding in this area. Work towards the development of best practice principles will move practice towards transparency in the understanding and delivery of goal‐oriented practices.
Challenges to the ancient methane seep search strategy: The Bedford Canyon Formation (Middle Jurassic, Santa Ana Mountains, California)
Authors: Shapiro Russell S. , Ingalls Miquela
Published: December 2024

Carbonates formed by anaerobic oxidation of methane at localized seeps have been recognized in the rock record based on a list of criteria, including anomalous deposition within detrital facies, complex petrofabrics, seep‐endemic macrofauna and 13C‐depleted isotopic signatures. While much emphasis has been placed on the latter, it is only one of several tools used for identification. This study reports on two different and rare limestone units in the forearc deposits of the Jurassic Bedford Canyon Formation in the Santa Ana Mountains, California (USA). Isolated, metre‐scale limestone pods were found to host abundant endemic Anarhynchia dimerelloid brachiopods and display diverse petrofabrics, including multiple generations of cements. However, the δ13C values of the petrofabrics ranged from −14.5 to 4.52‰ Vienna PeeDee Belemnite. These values are only slightly 13C‐depleted relative to contemporaneous seawater, thus likely recording a stronger component of oceanic dissolved inorganic carbon than hydrocarbons. Additionally, although the petrofabrics are common for seeps (primary micrite, microbialite, pelsparite, intraclastic micrite; early isopachous and botryoidal cements and yellow calcite; late‐stage void‐filling spar), the isotopic values did not follow a predicted trend of increasing δ13C with paragenetic sequence. Pelsparite δ13C values ranged from −10.65 to −7.09‰ Vienna PeeDee Belemnite while coarse spar and vein cements ranged from −11.42 to −2.44‰ Vienna PeeDee Belemnite. Olistostromes composed of brecciated pelmicrite sourced from shallow fringing‐arc environments are typical of forearc settings. Olistostromes in the Bedford Canyon Formation contain much lower δ13C values than the more classically characterized seep deposits, ranging from −21.77 to −10.78‰ Vienna PeeDee Belemnite. While the original shallow‐water source may not have a been a confined seep, the low δ13C values require the incorporation of carbon sourced from the oxidation of localized hydrocarbons. Together, these findings recommend a reconsideration of the weight placed on δ13C values as the key criterion for distinguishing seeps in the rock record.
The myth of cultural fit in recruitment job interviews
Authors: Bonelli Nilma , Zhu Hua
Published: December 2024

This article aims to examine the complex linguistic and cultural dynamics of recruitment interviews where recruiters played multiple roles of gatekeepers and facilitators by unpacking how “cultural fit” is co‐constructed in recruitment interviews. Drawing on ethnographic data collected from one of the world's largest recruitment agencies, we explore how power dynamics manifest in “friendly” rapport‐building interview conversations between interlocutors of diverse ethnic and linguistic backgrounds in an Inner Circle context. Our analysis shows that candidates are required to play a power game, demonstrating alignment with recruiters’ agendas and complying with recruiters’ dictated level of appropriateness in conversational style, such as formality and code. Candidates who are less familiar with their roles in the power game masked by the conversation style of faking friendship are left at a disadvantage and labeled as unsuitable cultural fit. These findings highlight the previously overlooked influence of recruiters in shaping interview outcomes.
Spatial Packaging and Routing Optimization of Complex Interacting Engineered Systems
Authors: Behzadi Mohammad M. , Zaffetti Peter , Chen Jiangce , Zeidner Lawrence E. , Ilieş Horea T.
Published: December 2024

Designing the 3D layout of interconnected systems (SPI2), which is a ubiquitous task in engineered systems, is of crucial importance. Intuitively, it can be thought of as the simultaneous placement of (typically rigid) components and subsystems, as well as the design of the routing of (typically deformable) interconnects between these components and subsystems. However, obtaining solutions that meet the design, manufacturing, and life-cycle constraints is extremely challenging due to highly complex and nonlinear interactions between geometries, the multi-physics environment in which the systems participate, the intricate mix of rigid and deformable geometry, as well as the difficult manufacturing and life-cycle constraints. Currently, this design task heavily relies on human interaction even though the complexity of searching the design space of most practical problems rapidly exceeds human abilities. In this work, we take advantage of high-performance hierarchical geometric representations and automatic differentiation to simultaneously optimize the packing and routing of complex engineered systems, while completely relaxing the constraints on the complexity of the solid shapes that can be handled and enable intricate yet functionally meaningful objective functions. Moreover, we show that by simultaneously optimizing the packing volume as well as the routing lengths, we produce tighter packing and routing designs than by focusing on the bounding volume alone. We show that our proposed approach has a number of significant advantages and offers a highly parallelizable, more integrated solution for complex SPI2 designs, leading to faster development cycles with fewer iterations, and better system complexity management. Moreover, we show that our formulation can handle complex cost functions in the optimization, such as manufacturing and life-cycle constraints, thus paving the way for significant advancements in engineering novel complex interconnected systems.
Novel Design of Wrist With Gripper: Type Synthesis of a 2R1T Parallel Mechanism Possessing One Actuation Degree-of-Freedom
Authors: Zhang Jingyao , Yao Jiantao
Published: December 2024

The parallel mechanism (PM) with a configurable movable platform (CMP) holds the potential for achieving a high-response speed and high-stiffness integrated design of a gripper-wrist system. The motion of two rotations and one translation (2R1T), closely resembling the movement of a human wrist joint, is highly complex. Therefore, research on 2R1T PM with CMP remains unexplored. Additionally, a systematic method for constructing PM with CMP is also lacking. This paper proposes fundamental design principles for PM with CMP. The topological arrangements of 2R1T PM with CMP are classified according to the number of limbs, their types, and the CMP structure. The basic constraint conditions and the redundant constraint conditions of 2R1T PM are analyzed. By establishing the relationship between finite motions, joint geometric parameters, and constraint screws, a series of limb structures that provide specific constraints in finite motions are constructed. Several configuration examples of gripper-wrist mechanism are provided, which can serve as a guide for subsequent researches. The design approach of CMP is discussed. The performance advantages of such mechanisms are validated through simulation-based comparisons.
Operational Flexibility Evaluation and Techno-Economic Analysis on Hot Primary Air Temperature Boosting by Reheated Steam in a Lignite-Fired Power Plant
Authors: Li Maoliang , Pan Shaocheng , Li Weicheng , Lin Xiaolong , Liu Yinhe
Published: December 2024

Coal-fired power plants are commonly used as adjustable power sources to complement the fluctuating output of wind and solar energy. The investigation is required to determine the flexible peak-shaving capabilities of coal-fired boilers. A modified scheme for a lignite-fired power plant to further improve the primary air temperature using the outlet steam from the low-temperature reheater is studied while increasing the inlet flue gas temperature of the air preheater is considered the conventional scheme. Thermodynamic models of the power plant are constructed using ebsilon software. The operational characteristics of both schemes are compared under 30% turbine heat acceptance (THA)–100%THA conditions and the economic performance of the modified scheme is also evaluated. Results indicate that the modified scheme exhibits superior thermodynamic and economic performances compared to the conventional scheme. The disparity in power generation efficiency between the conventional and modified schemes reaches a maximum of 0.23 percentage points under 75%THA conditions. The net present value of the modified scheme amounts to 4.51 million dollars over the power plant lifespan of 30 years. The modified scheme allows the conventional denitrification catalyst to maintain an optimal temperature range even under 30%THA conditions, resulting in a power generation efficiency only 4.8 percentage points lower than that under 100%THA conditions, thus demonstrating remarkable operational flexibility. This study presents an efficient, cost-effective, and adaptable approach for lignite-fired power plants.
Efficient Aerodynamic Uncertainty Quantification for a Three-Dimensional Transonic Fan Rotor
Authors: Zhang Qian , Meng Dejun , Xu Shenren , Wang Dingxi , Hang Xiuquan
Published: December 2024

Manufactured compressor blades deviate from their intended design, leading to a shift in the mean and scattering of aerodynamic performance. To mitigate performance deterioration without increasing manufacturing costs, an accurate and efficient evaluation of aerodynamic uncertainty, known as uncertainty quantification (UQ), is crucial. The high cost of three-dimensional computational fluid dynamics (CFD) simulations has prompted UQ studies to predominantly target two-dimensional cases or extend to three dimensions with a limited number of geometric variables. Since geometric deviations exist at various positions on three-dimensional blades, accurately describing them would necessitate a high-dimensional geometric deviation space. To investigate high-dimensional uncertainty problems, an efficient adjoint-based UQ method is proposed and demonstrated using the three-dimensional transonic fan, NASA Rotor 67. The method proves to be not only hundreds of times faster than full-fidelity CFD but also yields results with satisfactory accuracy. The investigation into the underlying mechanism reveals that geometric uncertainties significantly influence shock waves, tip clearance vortices, corner vortices, and the radial distribution of three-dimensional flows, ultimately resulting in deviations in aerodynamic performance.
Optimal Riblets Applied to Gas Turbine Compressor Blades Studied via Direct Numerical Simulation (GT2024–122305)
Authors: Kozul Melissa , Nardini Massimiliano , Przytarski Pawel J. , Solomon William , Shabbir Aamir , Sandberg Richard D.
Published: December 2024

Streamwise micro-groove surfaces (“riblets”) are well known as a passive surface treatment to reduce drag, which may assist in increasing overall gas turbine efficiency. The first direct numerical simulation of micro-scaled riblets on an axial high-pressure compressor blade at engine-relevant conditions (Kozul et al., 2023, “Direct Numerical Simulation of Riblets Applied to Gas Turbine Compressor Blades at On- and Off-Design Incidences.” Proceedings of the ASME Turbo Expo, Boston, GT2023–10103) demonstrated the ability of riblets to reduce the skin friction along most of the chord of a high-pressure compressor blade, at both on- and off-design inflow incidences. However, this previous study only considered riblets with fixed physical dimensions. The present work considers a “locally optimal” riblet geometry applied to the high-pressure compressor blade, where the riblet geometry is smoothly adjusted along the chord to target optimal riblet dimensions in viscous units, known from fundamental fluid mechanics studies. The present locally optimal riblets do indeed reduce the skin friction on the surface of the high-pressure compressor blade at both design and off-design inflow incidences and are generally at least as effective as the previous fixed-geometry riblets. Yet, the present riblet surfaces tend to increase pressure wake losses. In particular, at positive incidence, although the locally optimal riblets generally further reduce the skin friction compared to the fixed riblets, the wake loss increases by a significant 20% with respect to the reference smooth-blade case. A complex flow interaction with the suction-side separation bubble at the leading edge may be responsible for the significantly increased loss at positive inflow incidence.
Risk Based Asset Management Model for Managing External Corrosion on Natural Gas Transmission Pipelines
Authors: Hommes Martin , Jager Eric
Published: December 2024

Gasunie operates a natural gas transmission system in the Netherlands. External corrosion is one of the threats. Gasunie applies coating, cathodic protection and in-line inspection (ILI) as the best-industry practices to manage external corrosion.

Globally, there is a general trend to increase ILI. Gasunie started its comprehensive ILI-program in 2000. This has resulted in solid historical corrosion data. Furthermore, Gasunie has been and still is improving CP. Currently, (re)inspection intervals are calculated with pipeline parameters and assumptions on defect dimensions and corrosion rate. This is independent of risk.

Gasunie applies risk based asset management to balance expenditures on and risks of the transmission system. Risk of unwanted events, such as a pipeline rupture, is monetized. Specifically for external corrosion, Gasunie aims to determine (re)inspection intervals based on risk, i.e. risk based (re)inspection intervals. This means shorter (re)inspection in case of a higher risk and vice versa.

Risk of external corrosion is defined by failure frequency as function of time, failure mode and consequences of failure. Failure frequency is determined based upon historical corrosion data, especially defect dimensions and defect densities. Consequences are determined for the following categories financial damages, environment, transportation reliability and safety. This model is unique, because it determines the net present value of monetized risk as a function of time for external corrosion taking into account local differences in relevant parameters and local conditions. Moreover, (re)inspection intervals are determined based upon risk. This paper presents work in progress of this risk model.
Uplift Mitigation Strategies for Pipeline Overbends
Authors: Phillips Ryan , Martens Michael , Thompson Shawn , Barrett John , Piercey Gerry
Published: December 2024

Pipeline upheaval buckling due to insufficient vertical restraint and ratcheting caused by cyclic loading are especially challenging issues, with each likely to occur at overbends. A primary factor contributing to the uplift resistance available to counteract upheaval buckling is the strength of, and the ability to mobilize the overlying soil. Overbends have the potential to require additional uplift resistance, over and above that provided by the native backfill, to resist upheaval buckling. This buckling has primarily been mitigated by relying on increased soil cover or through the use of screw anchors in competent soils. These mitigations have drawbacks, as greater than required burial depths add to construction time and cost, while screw anchors can increase localized stresses on the pipeline. To assess currently available uplift resistances and evaluate the effects of various potential mitigation measures, a series of laboratory uplift tests using scaled pipe sections and granular backfills were completed. To address insufficient uplift resistance, a series of prototype mitigation measures were chosen for proof of concept testing. The design of each measure focused on increasing the peak uplift resistance and maintaining a residual resistance closer to the peak, without significantly increasing cover depths or stresses applied to the pipeline. Three of the concepts tested, a structural cap layer, pipe stirrups and a rigid open saddle each widened the soil column mobilized during uplift, increasing the peak resistances achieved in scaled testing, while also maintaining the integrity of the soil block at larger displacements, thus reducing the decay often seen in residual resistances. These concepts showed promise and were advanced from prototype to a field deployable design.
Transition Curve Fitting of Charpy Test
Authors: Zhang Fan
Published: December 2024

The Charpy V-notch (CVN) impact test is a typical method used to evaluate steel pipe toughness and resistance to fracture propagation. The CVN tests are generally conducted at multiple temperatures in order to capture the transition from the brittle regime with low impact energy to the ductile regime with higher impact energy. This transition behavior is represented by the variation with temperature in either measured impact energy or observed shear area percentage at the fracture cross section. Transition curves fitted from raw test data are used to derive key parameters, such as upper shelf impact energy (EUS) and Shear Area Transition Temperature (SATT). There are multiple procedures available to derive the transition curves, two of which are widely used. One was developed by M. Rosenfeld in 1996 by proposing the shear area as a sigmoidal function of temperature. The other is recorded in Section 9F.2.3 of API 579/ASME FFS-1 (2021), where the impact energy is expressed by a hyperbolic tangent function of temperature. The various fitting approaches may result in different derived EUS and SATT values, generating an unnecessary barrier for an operator comparing pipe properties or building up toughness distribution within a pipeline based on tests from multiple labs. For consistency, it may be necessary to repeat the transition curve fitting with a unified approach on raw test data instead of using lab reported EUS and SATT values. The derived EUS and SATT values of the tested specimen size can then be converted to the equivalent full-size values, such as by following Zhang and Rosenfeld’s (2022) approach, for the purposes of comparison, building up a database, determining distribution, or any other integrity assessment tasks. In this paper, it is first demonstrated that Rosenfeld’s sigmoidal equation and API 579/ASME FFS-1’s hyperbolic tangent equation are equivalent. Based on that similarity, a simplified fitting procedure is recommended for fitting the transition curves of shear area and impact energy over temperature. The mathematical detail of the fitting process is provided in the Appendix of the paper for implementation purposes. Finally, the performance of the procedure is demonstrated through worked examples.
Evaluation of Selective Seam Weld Corrosion Susceptibility
Authors: McMahan Tara Podnar , Amend Bill , Harper William , Bubenik Thomas , Evans Kenneth , Rosenfeld Michael , Li Yanping
Published: December 2024

Selective seam weld corrosion (SSWC) in autogenous welds is characterized by accelerated corrosion of or near the bondline which results in a groove-like feature that often coincides with shallower corrosion that can extend beyond the width of the longitudinal seam. Historically, SSWC has been referred to as “grooving corrosion”, “knife-line attack”, or “trench-like corrosion”. In 2021, the Pipeline Research Council International, Inc. (PRCI) funded a project, PRCI Project EC-2-12, to evaluate SSWC as a threat to gas and liquid pipeline systems. The project included a literature review of key parameters influencing the likelihood of SSWC within a particular type of pipe over others, benchmarking of the key parameters using industry experience and data, and the development of a susceptibility process for the threat of SSWC within gas and liquid pipeline segments.

From the literature review, a summary of hypothesized influencing parameters was compiled and those considered more strongly and consistently indicative of susceptibility were identified as key parameters (e.g., longitudinal seam weld type, chemical composition of the plate material, and evidence of a post-weld heat treatment, etc.). The key parameters were then benchmarked against pipeline industry data from confidential as well as public sources. Industry data were collected for line pipe known to be susceptible to the threat of SSWC (i.e., SSWC has been identified within it through direct examination and/or metallurgical analysis). Additionally, mill test reports for line pipe manufactured prior to 1990 and historical line pipe manufacturing specifications that could indicate typical manufacturing practices of the time were collected and compiled.

As a result of the benchmarking effort, some key parameters were confirmed, and others were dismissed if industry data indicated it was unlikely they could be relied upon to determine susceptibility to the threat of SSWC individually or in concert with other parameters. Key parameters that were confirmed as reliable through industry benchmarking and considered readily accessible to most pipeline operators were leveraged in the development of a susceptibility framework.

The following paper details the sources identified as a result of a comprehensive literature review, the SSWC susceptibility parameters with industry consensus, the SSWC susceptibility parameters determined to be reliable as a result of a benchmarking study, and a SSWC susceptibility framework that can be used to categorize and prioritize segments for a baseline assessment relative to the threat of SSWC.
Revision of Material Requirements of the EPRG Tier 2 Guidelines for Weld Defect Acceptance
Authors: Hertelé Stijn , Huising Otto Jan
Published: December 2024

The 2014 modification of the EPRG Tier 2 guidelines for the assessment of girth weld defects includes a modified criterion for weld strength overmatching. First experiences have shown it to be highly restrictive and to potentially limit the use of manual girth welding techniques. Recognizing this, EPRG launched a project to develop a sound justification to a potential new modification of the EPRG weld strength criteria, supported by a database of mechanical weld characteristics provided by EPRG members and a probabilistic analysis. This paper summarizes the findings of the project.

The weld strength undermatch probability is strongly influenced by the ratio between overmatch criterion and standard deviation of pipe yield strength. The current guidelines correctly reflect the importance of this ratio, which is prescribed to be five. However, the requirements table of the guidelines mentions a fixed overmatch criterion of 100 MPa. The inherent assumption of 20 MPa for standard deviation of pipe yield strength is not mentioned and therefore easy to overlook. In the next issue the table will be modified such that it reflects the “five standard deviations” idea.

The modified requirements stimulate the use of pipeline steels with a lower variability yield strength, as illustrated by the Dutch code NEN 3650-2. This code involves pipe yield strength and overmatch criteria in line with the suggested modification.
Modernizing Aerial Patrol - Real Life Remote Sensing for Liquid Leak and Threat Detection Along the Right of Way: First Detection Demonstrations of a Real Pipeline Seeper Leak, Encroachments, and Exposed Pipes Using a Traditional Aerial Patrol Plane
Authors: Chenevey Paige , Thibeault Alexandre , Beard Joshua , Bergeron Eric
Published: December 2024

Since the end of 2022, Marathon Pipe Line LLC (MPL) has been using and testing Flyscan Systems’ (Flyscan) remote sensing technology over their liquid pipeline right of way (ROW) to benchmark and validate the use of machine learning (ML) algorithms, photogrammetry, and hyperspectral imaging to perform real-time threat detection, liquid leak detection of crude oil and refined products, as well as other advanced imaging features related to geo-hazards.

This paper presents scientific approaches and real-life results from over 200 aerial patrols between November 2022 and December 2023, covering over 50,000 miles and identifying more than 3,000 potential threats over ROWs in diverse landscapes across the United States — from the subpolar forests of Alaska to the shrublands of Texas.

To the best of our knowledge, this paper also describes a reported finding where a hyperspectral system was used to detect a real underground seeper diesel leak during a ROW aerial patrol flight. Further examples noted in the paper include the detection of contaminated soils from third-party activity, the detection of real encroachment, and massive documentation of various types of objects in the ROW. Finally, examples of new imaging capabilities are discussed, including detection of exposed pipes after serious weather events, vegetation analysis, and erosion monitoring for Depth of Cover (DOC).
Design Code Considerations for Pipeline Overbends
Authors: Phillips Ryan , Martens Michael , Thompson Shawn , Barrett John
Published: December 2024

Pipeline overbends have significant design challenges and require additional consideration. The significant initial out-of-straightness created by an overbend increases the risk for upheaval buckling. Upheaval buckling can be combated during the design phase using wall thickness, burial depths and backfill specifications. The design requirements may vary depending on the design guidelines and methodologies applied. The soil uplift boundary condition drives a considerable amount of the cost. Better defining the uplift response can aid designers in selecting the appropriate methodology to implement. Potentially reducing pipe stresses and the need for additional mitigations. As allowable pipeline upward deformation limits generally exceed the yield displacement of the backfill the residual soil uplift resistance should be considered in overbend design including upheaval buckling. This becomes a large strain problem that many analyses do not consider. The use of DnV backfill resistance guidelines provides more uplift resistance in drained soils than those provided by the currently applied ALA & PRCI guidelines. These DnV guidelines have been extensively validated for low cover to pipeline diameter ratios, and properly account for both soil weight and its shear resistance. These equations can then be utilized to provide a more accurate representation of actual response conditions, resulting in a more economical design.