bluuebunny/crossref_metadata_2025 huggingface dataset:
Substantiation of Recommended Crack ILI Response, Onshore Pipelines
Authors: Lamborn Lyndon , Macrory Cara , Shie Taylor , Ibrahim Mahmoud
Published: December 2024

As pipeline crack threat management through in-line inspection (ILI) has now become standard practice, a normative response to inspection results is being recommended in the API RP 1176 refresh. Built upon primarily two data driven PRCI projects [1] [2], this paper links the findings of these two projects and provides additional justification for the normative crack ILI response criteria being integrated into the next release of API RP 1176.

Prior work is summarized herein to provide context includes historical incident and operator-provided ILI-NDE pair data analysis. This paper relates incident root causality to ongoing industry activities and adds a comprehensive crack reliability analysis demonstrating the effectiveness of the crack ILI response from a fully probabilistic viewpoint.

The reliability analysis operates on a comprehensive UTCD crack ILI dataset representative of current technology on actual operating assets in North America. The paper demonstrates that operator adherence to the recommended crack ILI response criteria results in acceptable reliability for a large real-world dataset. While there may be unique circumstances where crack ILI response criteria should be adjusted or augmented with other integrity provisions, the standard response proposed herein should be the industry baseline standard.

Forcing more stringent crack ILI response thresholds would not measurably reduce crack-related loss of containment incidents. Rather, such enforcement action would divert resources away from properly addressing incident root causes. Historical crack-related incidents have been demonstrated to have no causal links to response thresholds. Industry is taking appropriate action to address incident root causes and achieve reliability targets.
Development of Earthquake-Resistance Evaluation Method for Composite-Repaired Pipelines Considering Interface Delamination
Authors: Yamaguchi Hikaru , Mitsuya Masaki , Imai Yasuhito , Ohata Mitsuru
Published: December 2024

Buried gas pipelines play a crucial role in our modern infrastructure, and hence, ensuring both safety and uninterrupted supply by prompt repair in case of damage is a critical need. The composite repair method has been utilized for emergency repairs in pipelines, yet the earthquake resistance of the composite-repaired pipeline remains uncertain. This study aims to evaluate the resistance of pipelines repaired with composite materials against earthquake ground displacement through experiments and finite element analysis incorporating a cohesive zone model. An axial loading test was performed on a test pipe repaired with composite materials. During the experiment, delamination occurred at the interface between the steel pipe and composite repair, leading to internal water leakage. The average local strain in the pipe at the onset of internal water leakage exceeded the strain demand imposed by earthquake ground displacement, indicating the earthquake resistance of the composite-repaired pipeline under the experimental conditions. A finite element analysis utilizing a cohesive zone model was carried out to replicate the experimental delamination. In this analysis, the delamination penetrated earlier than in the experiment, suggesting that the developed analysis method can conservatively evaluate the earthquake resistance of the composite-repaired pipeline. Furthermore, the developed analysis method was applied under conditions differing from the experiment. In all cases, the strain in the pipe exceeded the strain demand from earthquake ground displacement before interface delamination penetrated. These findings lead to the conclusion that the composite-repaired pipeline demonstrated earthquake resistance.
Hydrogen: Live Transmission
Authors: Koronka Max , Cosham Andrew , Simpson Gemma , Senior Gary , Thomson Nancy , Bladon Sophie
Published: December 2024

The Local Transmission System (LTS) Futures project looks to produce a blueprint methodology for repurposing natural gas transmission pipelines to convey hydrogen. The project incorporates a range of small and full-scale testing and will culminate in a 6-month live trial whereby a 30 km, natural gas transmission pipeline shall be repurposed and operated with hydrogen. Mechanical testing of pipeline material, seam and girth welds in air and pressurized, gaseous hydrogen is underway to inform the development of repurposing standards. Full-scale burst testing of defects has been conducted to link small-scale testing to full-scale behaviour. Longer term, full-scale, fatigue testing of defects and new connections are underway. Operational activities, such as hydrogen flaring, live welding, and under-pressure drilling, have been investigated. An overview of testing completed to date is discussed.
Repair Welding of In-Service Hydrogen Pipelines - Concepts and Challenges -
Authors: Kaiser Sebastian , Erxleben Kjell , Rhode Michael , Kannengiesser Thomas
Published: December 2024

Hydrogen is set as the energy carrier of tomorrow for a more sustainable fossil fuel free future. As this necessitates a reliable transport infrastructure, repurposing of the existing natural gas grid is planned. With regards to the well-known effect of hydrogen embrittlement, the compatibility of utilized materials must be investigated. First comprehensive studies on pipeline material hydrogen compatibility indicate that these materials can be applied to a certain extent. Nonetheless, the material compatibility is currently of high interest and focus of numerous research projects worldwide. However, pipelines require frequent maintenance and repair work. As part of these, in some cases it is necessary to do weldments onto pipelines while they are pressurized. This in-service welding introduces additional challenges for the material compatibility. Due to the resulting high temperatures, the metallurgical changes in the material and of course the presence of high-pressure hydrogen in the pipeline, additional investigations need to be conducted to ensure that no critical material degradation because of increased hydrogen absorption occurs and an overall material compatibility is given. For this reason, the present paper introduces in-service welding on pipelines. An overview of current research projects that deal with the application of in-service welding specifically on hydrogen pipelines and the emerging problems when applying these techniques on hydrogen pipelines is given. Methods of material testing, their limits and possible solutions are presented and discussed.
Effects of Corrosion Pit Idealization Shape on the Susceptibility of Crack Initiation in the Analysis of Pipeline Dents Interacting With Corrosion
Authors: Agbo Sylvester , Muntakim Abu , Scott Colin , Sadowski Mark
Published: December 2024

External corrosion pitting is a common material degradation mechanism for steel pipelines resulting in a reduction of the pipe wall thickness (WT) within a localized, affected area, hereafter referred to as metal loss (ML). In many cases, corrosion pits interact with other major pipeline defects, such as dents; such interacting features can potentially increase the susceptibility to failure of in-service pipelines since both defects are stress and strain concentrators. There has been a lack of clarity and consensus on the generally accepted geometrical shape that should be used to model ML in pipelines for engineering analyses. As a result, ML in pipelines is being idealized with various geometrical shapes such as sharp-edge rectangular shapes, curved-edge rectangular shapes, and semi-ellipsoidal shapes. The effect of these variations in idealization shapes of ML features, especially while interacting with pipeline dents, needs to be investigated to provide clarity and suggest the best approach to simulate ML features in pipelines with a higher margin of safety. In this study, pressurized steel pipe with an outside ML defect was modelled using a curved-edge rectangular shape, a sharp-edged rectangular shape and a semi-ellipsoidal shape in ABAQUS™. A comparison of both hoop and von Mises stresses, and the equivalent plastic strain distributions of the pressurized pipe with different ML shapes was investigated. The ML shapes were used to conduct dent-metal loss interaction analysis to investigate the effect of varying dent depth on the pipeline’s susceptibility to crack initiation. Specifically, this study examined different dent depths interacting with an ML feature that was used to evaluate the susceptibility to crack initiation using dent formation strain limit and the ductile failure damage indicator (DFDI). It was found that different shapes show different stress concentration distributions. The results show significant variations in the susceptibility to cracking in pipelines with varying dent depths interacting with ML. This outcome may have a significant impact on pipeline integrity assessment and management planning.
Development of an Ultrasonic ILI Tool for the Assessment of Crack-Type Anomalies in Ammonia-Carrying Pipelines
Authors: Karé Raymond , Thielager Norbert , Fischer Maximillian , Shannon Colton
Published: December 2024

The in-line inspection (ILI) of pipelines used to transport anhydrous ammonia is challenging since several components that make up a typical ILI tool used for the inspection of oil and gas pipelines are not compatible with the anhydrous ammonia. Magnetic Flux Leakage (MFL) and Deformation (DEF) tools have been developed in the past to assess anhydrous ammonia pipelines for corrosion and deformation anomalies. However, assessing for crack-type anomalies has never been possible as no ammonia-compatible ultrasonic ILI tool has been developed. Feasibility studies have in the past been undertaken to address this problem but so far none of these investigations has resulted in a successful ultrasonic ILI tool build for inspection of ammonia carrying lines. As a result, the operators of these pipelines have been conducting ultrasonic ILI inspections using water to navigate the tool through the line during a hydrotest. This process is not only expensive, but it also causes months of interruptions in flow due to repairs and other factors related to the procedure. The opportunity to be able to conduct ultrasonic (crack) ILI inspections during the normal operation of this ammonia pipeline system would result in a significant cost saving for the client.

The paper will report on the findings of the project undertaken by NDT Global on behalf of NuStar Energy to investigate options for an ultrasonic ILI tool capable of detecting and sizing axial cracks, in particular fields of stress corrosion cracks (SCC), in ammonia-carrying pipelines. A description of the tool qualification and verification procedures will also be outlined.
An Analysis of Flow Strength Models for Failure Pressure Prediction of Metal Loss Features in Oil and Gas Pipelines
Authors: Scott Colin , Muntakim Abu
Published: December 2024

Failure pressure prediction of metal loss features is a vital part of any pipeline integrity management program. Assessments are typically performed using the ASME B31G based models. These models have evolved over the years, from the original to modified B31G models, to effective area / RSTRENG models, to the most recent PSQR model. Some of these methodologies are also included in API 579, BS 7910 and DNV corrosion flaw assessments. Recent work by PRCI has demonstrated these models, although increasingly refined in their approach, maintain a conservative bias in their failure pressure predictions. This decreases efficiency of the owner’s integrity programs. Some analysts have attributed the conservatism to limitations in the flow strength models used in the assessments.

This work uses finite element methods to analyze the stress and strain distributions at the bases of long metal loss flaws to better understand plasticity behavior during plastic collapse. A key parameter of interest is the Ramberg-Osgood hardening exponent, which characterizes flow of material during the failure process. Materials with higher or lower hardening exponents show differences in their stress and strain distributions. In effect, there are multiple “shades of grey” between purely elastic and purely plastic behavior. This has a follow-on effect on how flow strength should be defined for different flaw geometries. In some cases, the current flow strengths models are suitable. In other cases, the definition needs refinement. Recognition of these effects can contribute to optimizing current models.

The study also looks at currently available failure pressure data, from both in-service and laboratory tests. The trends observed in the flow strength modelling are considered with respect to the true failure strength of metal loss flaws. The results of the study provide insights into limitations of the current flow strength models and suggest possible improvements for improved failure pressure predictions going forward.
A Spill Volume Calculation Approach and its Positive Impacts on Pipeline Risk Management
Authors: Pires Luis Fernando G. , Barreto Claudio , Mesquita Rodrigo S. N. , Pacheco Anderson , Bahiense Ana Paula
Published: December 2024

The loss of containment in liquid pipelines is a significant concern for pipeline operators, service providers, and regulators. Estimating the potential spillage volume at a designated pipeline location is critical for societal risk analysis, environmental impact assessment, and emergency response planning.

The total spillage volume, after loss of containment, in each scenario consists of two parts: (a) the spill volume during operation while the pumps are active, and (b) the gravitational spillage volume after the pumps are shut down. A common industry practice to determine the operational spillage volume involves using commercial transient thermo-hydraulic simulation software. This software allows modeling the intended bore opening at a specified location and, through numerical simulation, defines the spillage volume within the time span required for the control room to detect the issue and respond by deactivating the pumps. Calculating this time span in advance for each scenario is essential.

In recent years, there has been a notable increase in the demand for spillage volume simulation in Brazil, propelled by the regulatory requirement for risk studies. This surge is particularly driven by the need for comprehensive environmental analyses related to pipeline water-crossings and quantitative risk assessments that consider the population residing in high-consequence areas. Brazilian environmental agencies now mandate the evaluation of three distinct pipeline failure scenarios: (i) a pinhole with a diameter ratio d/D of 5%, (ii) a hole with a 20% diameter ratio, and (iii) a rupture with 100% internal diameter size.

The increased demand has led to a significant rise in the utilization of numerical models and simulations. To meet this challenge, simplified hypotheses have been formulated. These hypotheses facilitate the computation of potential spillage volume during operation without relying on transient thermohydraulic software. Through the development and implementation of an algorithm, it becomes feasible to derive a comprehensive profile of the total spillage volume (both operational and gravitational) along the pipeline, based on the chosen discretization.

The innovative tool, MAVAZ, developed by SIMDUT/PUC and TRANSPETRO, has proven effective in meeting the requirements of Brazilian regulators. MAVAZ’s calculation modules consider factors such as valve closure and spill containment times, offering a comprehensive approach to spill event analysis. The continuous development of MAVAZ calculation modules over the years has enhanced the realism of potential maximum leaked inventories, resulting in a more accurate calculation, and reducing the level of conservatism. Consequently, there have been positive impacts on cost optimization associated with pipeline risk management, both in risk analysis studies and in mitigating potential consequences through improved emergency response resources.
Risk and Resistance Fragility Model of Natural Gas Transmission Pipeline
Authors: Peng Yi , Bozorgnia Yousef , Ayello Francois , Honegger Douglas , Kottke Albert
Published: December 2024

This paper summarizes the findings from a research project focused on the quantification of seismic risk for natural gas pipelines and gas storage facilities in California. A comprehensive database, consisting of risk and resistance models of gas transmission pipelines, was developed using finite element analysis. This open-source computer tool can predict the probabilities of pipeline failure using pre-computed earthquake hazard estimates, facilitating informed decisions on pipeline maintenance and management.

This study began by establishing generic modeling approaches for quantification of seismic hazards such as surface faulting, liquefaction and landslides. Non-linear pipe-soil interaction finite element analyses (FEA) were conducted to assess the sensitivity of pipeline response to geohazard characteristics and pipeline specifications. Based on the sensitivity analysis results, each parameter was ranked by importance and 551,789 nonlinear pipe-soil interaction FEA were performed using ANSYS software. These simulations considered geohazard and variables of straight pipelines, such as length of pipeline exposed to ground movement, the direction and amplitude of ground movement, soil strength, depth of burial, pipe diameter, pipe wall thickness, etc.

The FEA results were aggregated into a comprehensive database, from which Bayesian network models to predict the level of pipe strain from ground displacement (strain demand) were created. Simultaneously, a fracture model was developed to determine the pipeline strain capacity. The strain demand and strain capacity models were then combined to predict the probability of pipeline failure. All results are integrated into a user-friendly, open-source platform designed for natural gas infrastructure risk assessment. While the current platform is specific to geohazards in California, providing open-source access allows users to adapt the platform to their specific needs. The platform allows users to (1) perform risk assessments at different levels of complexity and sophistication, (2) use the platform as a decision support system for proactive gas infrastructure risk management, and (3) create or upload new models and data if needed.
Evaluation of High-Resolution Downhole Tubular Inspection Tools by Full-Scale Field Testing
Authors: Tao Gang , Doan Quy , Islam Abrar , Abdulhameed Diana , Scoging Allen , Cardiff Steve
Published: December 2024

Downhole tubular corrosion poses a significant threat to underground gas storage (UGS) well integrity. Therefore, integrity management of UGS wells requires periodic inspection of tubular conditions using various inspection tools to properly identify and size corrosion anomalies. The corrosion inspection data are then used to estimate corrosion growth rates and the remaining strength of the tubulars through various methods. However, the calculated remaining life and remaining strength can have a significant uncertainty due to the variations of the input parameters, including the corrosion growth rate, accuracy of reported corrosion feature sizes from the inspection tools, tubular material property variations, uncertain in-situ load conditions, and prediction model uncertainties.

In order to improve the tubular corrosion management for UGS wells, this study focused on a quantitative performance evaluation of a few selected state-of-the-art downhole tubular corrosion inspection tools based on a full-scale field test program. This paper presents the process and methodology of the field test and performance evaluation of four high-resolution tools based on principles of ultrasonic testing and magnetic flux leakage, which can provide relatively accurate sizes (including depth, length and width) of corrosion features. Statistical approaches were employed to determine the quantitative tool performance metrics, including the probability of detection, probability of false call and sizing accuracy. Moreover, the statistical performance results not only allow the determination of the feature sizing tolerances that can be used in deterministic integrity assessment methods but also provide valuable inputs for further development of a probability-based tubular integrity assessment workflow.
Technical ILI System – Verification Versus Validation Based on Sound Engineering Practice Solely on Industry Recognized and Standardized Methodology
Authors: Hoening Patrick , Stubbe Thomas
Published: December 2024

For the qualification of technical In-Line Inspection (ILI) systems for pipeline inspections, API 1163 standard allows two different approaches to demonstrate the system’s performance; verification or validation, based on tests or simulations and validation using historical data, i.e. verified field measurements from excavations.

Verification ensures evidence of the entire performance specification in terms of Probability of Detection (POD), Probability of Identification (POI) and sizing capability, while validation defends the performance specification on a sample basis respectively derives individual aspects of the as-run performance. Successful verification of the ILI system should be a prerequisite for carrying out the validation.

Usually, verification takes place on test fields or in laboratories under controlled conditions in order to test the essential variables and thus to prove every aspect of the performance specification in regards to POD, POI and sizing capability.

API 1163 provides statistical methods for the practical implementation of measurement performance qualification, but these methods are described solely for the validation approach. This paper closes the gap by adapting industry recognized and standardized statistical methodologies to the problem of verifying technical ILI systems in terms of detection and sizing and comparing these methods to the ones, described in API 1163, proposed for the system’s validation.

Specifically, these methods for verifying ILI performance are the 29/29 method with Clopper-Pearson for POD and the Expanded Measurement Uncertainty method for sizing in accordance with GUM.
Robust guided wave inversion for estimating bone thickness and elasticity
Authors: Le Ductho , Sacchi Mauricio D. , Lou Edmond , Le Lawrence H.
Published: December 2024

Accurately characterizing bone properties using quantitative ultrasound remains a significant challenge due to the dispersive nature of guided waves, limited observations, irregularity of bone structure, and heterogeneity of bone tissues. In this paper, an inversion technique is proposed that combines weighted mean absolute criteria and the simulated annealing algorithm to extract the thicknesses and elastic properties of a bilayer bone model. By utilizing the L1 norm with an appropriate weighting parameter, this method effectively reduces the influence of outliers and noises commonly encountered in ultrasonic data, leading to more accurate estimation. This paper also introduces an asymptotic scheme to significantly reduce the search domain, improving the speed and precision of the inversion process. This approach employs a spectral collocation method as a forward modeling technique to simulate guided waves in a bone plate coated by a soft tissue layer. This paper validates the inversion using simulated and ex vivo data and demonstrates its ability to estimate features of cortical bone and soft tissue with high accuracy. Results are presented for the isotropic model. These findings hold great promise for the accurate characterization of bone properties using quantitative ultrasound, with potential applications in clinical diagnosis and treatment of bone-related diseases and injuries.
Quantifying articulatory variations across phonological environments: An atlas-based approach using dynamic magnetic resonance imaging
Authors: Xing Fangxu , Zhuo Jiachen , Stone Maureen , Liu Xiaofeng , Reese Timothy G. , Wedeen Van J. , Prince Jerry L. , Woo Jonghye
Published: December 2024

Identification and quantification of speech variations in velar production across various phonological environments have always been an interesting topic in speech motor control studies. Dynamic magnetic resonance imaging has become a favorable tool for visualizing articulatory deformations and providing quantitative insights into speech activities over time. Based on this modality, it is proposed to employ a workflow of image analysis techniques to uncover potential deformation variations in the human tongue caused by changes in phonological environments by altering the placement of velar consonants in utterances. The speech deformations of four human subjects in three different consonant positions were estimated from magnetic resonance images using a spatiotemporal tracking method before being warped via image registration into a common space—a dynamic atlas space constructed using four-dimensional alignments—for normalized quantitative comparisons. Statistical tests and principal component analyses were conducted on the magnitude of deformations, consonant-specific deformations, and internal muscle strains. The results revealed an overall decrease in deformation intensity following the initial consonant production, indicating potential muscle adaptation behaviors at a later temporal position in one speech utterance.
Patient Adherence for Blended Physiotherapy in Patients With Chronic Pain: A Critically Appraised Topic
Authors: Miranda Cynthia , Russ Anne C. , Tierney Ryan T. , Mansell Jamie L.
Published: December 2024

Clinical Scenario: Chronic pain conditions affect approximately 30% of the world’s population, and treatment plans are often complex. 70% of patients fail to adhere to prescribed home exercise programs. One possible solution is blended physiotherapy, which combines in-person physical therapy and web-based applications to support. Clinical Question: In patients with chronic pain, is blended physiotherapy an effective approach to patient adherence when compared to traditional rehabilitation interventions? Summary of Key Findings: The literature search included studies including any form of blended physiotherapy assessing patient adherence outcome measures. A total of 22 were identified for inclusion criteria, and three were identified for data synthesis. Two studies found significant increases in patient adherence when applying blended physiotherapy. The third study reported lower patient adherence when comparing blended physiotherapy to standard treatment methods. Clinical Bottom Line: Current low-level evidence supports the use of blended physiotherapy as an effective approach for adherence in patients with chronic pain. Blended physiotherapy reported in the literature consisted of video-supported exercises; self-management skills; pain management education; and telephone support for low-, medium-, and high-risk patients with chronic pain. Use of blended physiotherapy promotes patient engagement and may enhance a patient-centered care environment.
Efficacy of a Multicomponent Physical Activity Intervention for Teachers With or At Risk of Type 2 Diabetes: The Support, Motivation, and Physical Activity Research for Teachers Health Randomized Controlled Trial
Authors: Plotnikoff Ronald C. , Murphy Maria , Wilczynska Magdalena , Courneya Kerry S. , Brown Wendy J. , Sigal Ronald J. , Lubans David R.
Published: December 2024

Background: Type 2 diabetes is a major cause of illness and disability and physical activity reduces these risks. The SMART Health study aim was to compare the efficacy of a multicomponent intervention to promote aerobic physical activity and resistance training in schoolteachers at risk of or diagnosed with type 2 diabetes, with and without a technology-based behavior change package. Methods: We randomized participants (N = 104) into 3 groups: “wait-list” control group, 5 face-to-face visits with a psychologist and exercise specialist (SH group), or 5 face-to-face visits over a 3-month period with a psychologist and exercise specialist, plus a technology-based behavior change package for an additional 6 months (SH+ group). Physical activity was the primary outcome (daily steps measured by pedometers). Systolic and diastolic blood pressure, waist circumference, body mass index, fasting blood glucose, glycosylated hemoglobin, plasma lipids, self-reported resistance training, anxiety and depression were also assessed at 3 and 9 months (primary time point). Linear mixed models were used to assess the intervention efficacy of SH and SH+ compared with wait-list control. Results: There were no significant group-by-time effects for steps in the SH or SH+ groups compared to the wait-list control group. Self-reported participation in monthly minutes of resistance training significantly increased at 3-month postbaseline in both groups (SH: 136 min, P < .01, d = 0.33 and SH+: 145 min P < .001, d = 0.4) versus the control group. The improvements were maintained for the SH group at 9 months. There was also a meaningful effect (P < .06, d = −0.23) for reducing anxiety for SH group at 9 months. Conclusions: SMART Health was a feasible, multicomponent intervention, which increased self-reported resistance training but no other secondary outcomes.
Model predictions of global geologic hydrogen resources
Authors: Ellis Geoffrey S. , Gelman Sarah E.
Published: December 2024

Geologic hydrogen could be a low-carbon primary energy resource; however, the magnitude of Earth’s subsurface endowment has not yet been assessed. Knowledge of the occurrence and behavior of natural hydrogen on Earth has been combined with information from geologic analogs to construct a mass balance model to predict the resource potential. Given the associated uncertainty, stochastic model results predict a wide range of values for the potential in-place hydrogen resource [10
3
to 10
10
million metric tons (Mt)] with the most probable value of ~5.6 × 10
6
Mt. Although most of this hydrogen is likely to be impractical to recover, a small fraction (e.g., 1 × 10
5
Mt) would supply the projected hydrogen needed to reach net-zero carbon emissions for ~200 years. This amount of hydrogen contains more energy (~1.4 × 10
16
MJ) than all proven natural gas reserves on Earth (~8.4 × 10
15
MJ). Study results demonstrate that further research into understanding the potential for geologic hydrogen resources is merited.
Two-in-one nanoparticle platform induces a strong therapeutic effect of targeted therapies in P-selectin–expressing cancers
Authors: Koshrovski-Michael Shani , Ajamil Daniel Rodriguez , Dey Pradip , Kleiner Ron , Tevet Shahar , Epshtein Yana , Green Buzhor Marina , Khoury Rami , Pozzi Sabina , Shenbach-Koltin Gal , Yeini Eilam , Woythe Laura , Blau Rachel , Scomparin Anna , Barshack Iris , Florindo Helena F. , Lazar Shlomi , Albertazzi Lorenzo , Amir Roey J. , Satchi-Fainaro Ronit
Published: December 2024

Combined therapies in cancer treatment aim to enhance antitumor activity. However, delivering multiple small molecules imposes challenges, as different drugs have distinct pharmacokinetic profiles and tumor penetration abilities, affecting their therapeutic efficacy. To circumvent this, poly(lactic-co-glycolic acid) (PLGA)–polyethylene glycol (PEG)–based nanoparticles were developed as a platform for the codelivery of synergistic drug ratios, improving therapeutic efficacy by increasing the percentage of injected dose reaching the tumor. Nonetheless, extravasation-dependent tumor accumulation is susceptible to variations in tumor vasculature; therefore, PLGA-PEG was modified with sulfates to actively target P-selectin–expressing cancers. Here, we show the potential of our platform in unique three-dimensional (3D) in vitro and in vivo models. The P-selectin–targeted nanoparticles showed enhanced accumulation in 3D spheroids and tissues of P-selectin–expressing BRAF-mutated melanomas and BRCA-mutated breast cancers, resulting in superior in vivo efficacy and safety. This nanoplatform could advance the codelivery of a plethora of anticancer drug combinations to various P-selectin–expressing tumors.
High-performance H
2
/CO
2
separation from 4-nm-thick oriented Zn
2
(benzimidazole)
4
films
Authors: Song Shuqing , Liu Qi , Swathilakshmi S. , Chi Heng-Yu , Zhou Zongyao , Goswami Ranadip , Chernyshov Dmitry , Agrawal Kumar Varoon
Published: December 2024

High-performance membrane-based H
2
/CO
2
separation offers a promising way to reduce the energy costs of precombustion capture. Current membranes, often made from two-dimensional laminates like metal-organic frameworks, have limitations due to complex fabrication methods requiring high temperatures, organic solvents, and long synthesis time. These processes often result in poor H
2
/CO
2
selectivity under pressurized conditions due to defective transport pathways. Here, we introduce a simple, eco-friendly synthesis of ultrathin, intergrown Zn
2
(benzimidazole)
4
films, as thin as 4 nm. These films are prepared at room temperature using water as the solvent, with a synthesis time of just 10 minutes. By using ultradilute precursor solutions, nucleation is delayed, promoting rapid in-plane growth on a smooth graphene substrate and eliminating defects. These membranes exhibit excellent H
2
permselectivity under pressurized conditions. The combination of rapid, green synthesis and high-performance separation makes these membranes highly attractive for precombustion applications.
Flexible adjustment of oxytocin neuron activity in mouse dams revealed by microendoscopy
Authors: Yaguchi Kasane , Miyamichi Kazunari , Tasaka Gen-ichi
Published: December 2024

Oxytocin (OT) neurons in the hypothalamic paraventricular nucleus (PVH) play an important role in various physiological and behavioral processes, including the initiation of milk ejection and the regulation of maternal behaviors. However, their activity patterns at the single-cell level remain poorly understood. Using microendoscopic Ca
2+
imaging in freely moving mouse dams, we demonstrate highly correlated pulsatile activity among individual OT neurons during lactation. The number of OT neurons engaged in the pulsatile activity significantly increased, along with a broadening of individual waveforms in the mid-lactation stage. Notably, only ~10% of the imaged OT neurons exhibited a significantly elevated response during pup retrieval, a hallmark of maternal behaviors, with a magnitude smaller than that observed during lactation. Collectively, these findings demonstrate the utility of microendoscopic imaging for PVH OT neurons and highlight the flexible adjustments of their individual activity patterns in freely behaving mouse dams.
Outer membrane lipoproteins: late to the party, but the center of attention
Authors: May Kerrie L. , Grabowicz Marcin
Published: December 2024

An outer membrane (OM) is the hallmark feature that is often used to distinguish “Gram-negative” bacteria. Our understanding of how the OM is built rests largely on studies of
Escherichia coli
. In that organism—and seemingly in all species of the Proteobacterial phyla—the essential pathways that assemble the OM each rely on one or more lipoproteins that have been trafficked to the OM. Hence, the lipoprotein trafficking pathway appeared to be foundational for the ability of these bacteria to build their OM. However, such a notion now appears to be misguided. New phylogenetic analyses now show us that lipoprotein trafficking was likely the very last of the essential OM assembly systems to have evolved. The emergence of lipoprotein trafficking must have been a powerful innovation for the ancestors of Proteobacteria, given how it assumed such a central place in OM biogenesis. In this minireview, we broadly discuss the biosynthesis and trafficking of lipoproteins and ponder why the newest OM assembly system (lipoprotein trafficking) has become so key to building the Proteobacterial OM. We examine the diversity among lipoprotein trafficking systems, noting uniting commonalities and highlighting key differences. Current novel antibiotic development is targeted against a small subset of Proteobacterial species that cause severe human diseases; several inhibitors of lipoprotein biosynthesis and OM trafficking have been recently reported that may become new antibiotics. Understanding the diversity in lipoprotein trafficking may yield selective new antibiotics that preferentially kill important human pathogens while sparing species of normal healthy flora.
Transcriptomic analysis of coxsackievirus B3 infection in induced pluripotent stem cell-derived brain-like endothelial cells
Authors: Hathcock Sarah F. , Mamana Julia , Keyzer Taryn E. , Vollmuth Nadine , Shokri Mohammad-Reza , Mauser Henry D. , Correll Robert N. , Lam Daryl W. , Kim Brandon J. , Sin Jon
Published: December 2024

Viral aseptic meningitis is a neuroinflammatory condition that occurs when viruses gain access to the central nervous system (CNS) and induce inflammation. The blood–brain barrier (BBB) is comprised of brain endothelial cells (BECs) that stringently regulate the passage of molecules, toxins, and pathogens from the circulation into the CNS. Through their unique properties, such as complex tight junctions, reduced rates of endocytosis, expression of efflux transporters, and restricted expression of leukocyte adhesion molecules, the BBB is often able to limit pathogen entry into the brain; however, certain neurotropic pathogens, such as coxsackievirus B3 (CVB3) are able to infect the CNS. We have previously demonstrated that CVB3 can infect and disrupt induced pluripotent stem cell-derived brain-like endothelial cells (iBECs), but the host response to this infection remains unknown. Here, we investigate global host transcriptional changes during CVB3 infection of iBECs using RNA sequencing. We validated our data set by exploring pathways altered by CVB3 using quantitative real-time PCR (qPCR) and enzyme-linked immunosorbent assay of upregulated cytokines and interferon signaling molecules.

IMPORTANCE

Coxsackievirus B3 (CVB3) is a leading cause of viral aseptic meningitis that can produce severe disease in susceptible individuals. To gain access to the central nervous system, CVB3 must cross central nervous system barriers, such as the blood–brain barrier. Previously, we have shown that CVB3 infects a human stem cell-derived brain-like endothelial cell model. Here, we report the global transcriptome of stem cell-derived brain-like endothelial cells to CVB3 infection and provide proof-of-concept validation of the dataset using molecular biology techniques. These data could inform novel mechanisms of CVB3-mediated blood–brain barrier dysfunction.
Gcn2 rescues reprogramming in the absence of Hog1/p38 signaling in
C. neoformans
during thermal stress
Authors: Goich David , Bloom Amanda L. M. , Duffy Sean R. , Ventura Maritza N. , Panepinto John C.
Published: December 2024

The fungus
Cryptococcus neoformans
is an opportunistic pathogen of humans that reprograms its translatome to facilitate adaptation and virulence within the host. We studied the role of Hog1/p38 in reprogramming translation during thermal stress adaptation and found that this pathway acts on translation
via
crosstalk with the Gcn2 pathway, a well-studied regulator of general translation control. Using a combination of molecular assays and phenotypic analysis, we show that increased output from the Gcn2 pathway in a Hog1 deletion mutant is associated with rescue of thermal stress adaptation at both molecular and phenotypic scales. We characterize known outputs of the Hog1 pathway during thermal stress as either Gcn2-dependent or Gcn2-independent and demonstrate that Hog1 activation regulates the Gcn2 pathway even in the absence of thermal stress. Finally, we implicate this phenomenon in another Hog1-regulated process, morphogenesis, and recapitulate Hog1–Gcn2 crosstalk in the distantly related fungal pathogen,
Candida albicans
. Our results point to an important link between the stress response machinery and translation control and clarify the etiology of phenotypes associated with Hog1 deletion. More broadly, this study highlights complex interplay between core conserved signal transduction pathways and the utility of molecular assays to better understand how these pathways are connected.

IMPORTANCE

Cryptococcus neoformans
is an opportunistic pathogen of humans that causes deadly cryptococcal meningitis, which is is responsible for an estimated 19% of AIDS-related mortality. When left untreated, cryptococcal meningitis is uniformly fatal, and in patients receiving the most effective antifungal regimens, mortality remains high. Thus, there is a critical need to identify additional targets that play a role in the adaptation to the human host and virulence. This study explores the role of the stress response kinases Hog1 and Gcn2 in thermoadaptation, which is a pre-requisite for virulence. Our results show that compensatory signaling occurs
via
the Gcn2 pathway when Hog1 is deleted, and that disruption of both pathways increases sensitivity to thermal stress. Importantly, our study highlights the insufficiency of using single-gene deletion mutants to study gene function, since many phenotypes associated with Hog1 deletion were driven by Gcn2 signaling in this background, rather than loss of direct Hog1 activity.
Development of an sRNA-mediated conditional knockdown system for
Chlamydia trachomatis
Authors: Ehses Janina , Wang Kevin , Densi Asha , Ramirez Cuper , Tan Ming , Sütterlin Christine
Published: December 2024

We describe a new
Chlamydia trachomatis
protein depletion method that uses an engineered small RNA (sRNA) to inhibit translation of a target gene. In proof-of-principle experiments, we induced functional knockdown of IncA, a fusion-mediating inclusion membrane protein, as shown with Western blots, loss of IncA staining at the inclusion membrane, and production of multiple chlamydial inclusions within an infected cell. These effects were titratable and reversible. To test for polar effects, we separately targeted the inclusion membrane proteins IncE and IncG, which are expressed from the
incDEFG
operon. Knockdown of IncE caused loss of IncE and its interacting host protein SNX6 at the inclusion membrane, without affecting IncG protein levels. Similarly, IncG knockdown significantly reduced IncG levels and prevented recruitment of its interacting host protein 14-3-3β, without altering IncE protein levels. These data provide the first genetic evidence that IncE and IncG are necessary for the recruitment of SNX6 and 14-3-3β, respectively, demonstrating the value of this knockdown approach. We also successfully depleted the major chlamydial surface protein, major outer membrane protein (MOMP), which is encoded by a likely essential gene that has not been previously disrupted or knocked down. MOMP knockdown caused severe defects in bacterial morphology and progeny production. Thus, our sRNA-based approach has broad potential as a conditional knockdown method for studying the function of
C. trachomatis
genes, including essential genes and genes in an operon.

IMPORTANCE

We describe a new method to reduce protein levels of a selected gene in the pathogenic bacterium
Chlamydia trachomatis
. This approach utilizes an engineered small RNA (sRNA) to inhibit translation of the mRNA for a target gene and produced inducible and reversible protein knockdown. Our method successfully knocked down four proteins, including a likely essential gene and individual genes in an operon, without altering protein levels of a neighboring gene. This conditional knockdown method will be useful for studying the function of genes in
Chlamydia
. It also has the potential to be applied to other obligate intracellular bacteria, including
Rickettsia
and
Coxiella
.
Draft genome sequence of
Bremerella cremea
LHWP2 isolated from dead ark clam revealing potential nitrogen metabolism pathways
Authors: Seo Jin-Hee , Yim Kyung June , Lim Jongbin , Chun Ji-Yeon , Lee Hae-Won
Published: December 2024

We present the draft genome sequence of
Bremerella cremea
LHWP2, a notable member of the Planctomycetes–Verrucomicrobia–Chlamydiae group, isolated from a dead ark clam. The 6,211,343-bp genome contains 5,304 coding gene sequences with a guanine–cytosine content of 56.5 %. The draft genome also reveals potential nitrogen metabolic pathways.
Near full-length genome sequence of a vesicular stomatitis New Jersey virus isolate collected from a naturally infected cow in the endemic state of Chiapas, Mexico
Authors: Valdez Federico , Velazquez-Salinas Lauro , Zhou Lawrence H. , Smoliga George R. , Fish Ian , Navarro-Lopez Roberto , Lopez-Gonzalez Irene , Hanley Kathryn A. , Mire Chad E. , Rodriguez Luis L. , Arzt Jonathan
Published: December 2024

Here, we report the near full-length genome sequence of a
Vesiculovirus newjersey
isolate obtained from a naturally infected cow (
Bos taurus
) in the state of Chiapas, Mexico. This sequence will support future efforts to improve our understanding of the evolutionary dynamics of this pathogen in endemic regions of Mexico.
Protein kinases MpkA and SepH transduce crosstalk between CWI and SIN pathways to activate protective hyphal septation under echinocandin cell wall stress
Authors: Doan Alexander G. , Schafer Jessica E. , Douglas Casey M. , Quintanilla Matthew S. , Morse Meredith E. , Edwards Harley , Huso Walker D. , Gray Kelsey J. , Lee JungHun , Dayie Joshua K. , Harris Steven D. , Marten Mark R.
Published: December 2024

This study investigates a previously unreported stress signal transduced as crosstalk between the cell wall integrity (CWI) pathway and the septation initiation network (SIN). Echinocandins, which target cell wall synthesis, are widely used to treat mycoses. Their efficacy, however, is species specific. Our findings suggest that this is due largely to CWI–SIN crosstalk and the ability of filamentous species to fortify with septa in response to echinocandin stress. To better understand this crosstalk, we used a microscopy-based assay to measure septum density, aiming to understand the septation response to cell wall stress. The echinocandin micafungin, an inhibitor of β-(1,3)-glucan synthase, was employed to induce this stress. We observed a strong positive correlation between micafungin treatment and septum density in wild-type strains. This finding suggests that CWI activates SIN under cell wall stress, increasing septum density to protect against cell wall failure. More detailed investigations, with targeted knockouts of CWI and SIN signaling proteins, enabled us to identify crosstalk occurring between the CWI kinase, MpkA, and the SIN kinase, SepH. This discovery of the previously unknown crosstalk between the CWI and SIN pathways not only reshapes our understanding of fungal stress responses, but also unveils a promising new target pathway for the development of novel antifungal strategies.

IMPORTANCE

Echinocandin-resistant species pose a major challenge in clinical mycology by rendering one of only four lines of treatment, notably one of the two that are well-tolerated, ineffective in treating systemic mycoses of these species. Previous studies have demonstrated that echinocandins fail against highly polarized fungi because they target only apical septal compartments. It is known that many filamentous species respond to cell wall stress with hyperseptation. In this work, we show that echinocandin resistance hinges on this dynamic response, rather than on innate septation alone. We also describe, for the first time, the signaling pathway used to deploy the hyperseptation response. By disabling this pathway, we were able to render mycelia susceptible to echinocandin stress. This work enhances our microbiological understanding of filamentous fungi and introduces a potential target to overcome echinocandin-resistant species.