bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Hydrogen Microgas Turbine Combustor: NOx Emissions and Secondary Air Injection
Authors: Tanneberger Tom , Mundstock Johannes , Rösch Sebastian , Rex Christoph , Paschereit Christian Oliver
Published: August 2024

On the way to defossilization, green hydrogen is a promising way to substitute natural gas (NG) and oil in the gas turbine industry. In the scope of the H2mGT project, a microgas turbine (mGT) burner with 100% hydrogen firing is developed and validated. The project is funded by the German BMWK, and it is a collaboration between Technische Universität Berlin (TUB) and the manufacturer Euro-K GmbH. It consists of three phases: (1) atmospheric pressure tests with a fused silica combustion chamber; (2) atmospheric pressure tests with counterflow-cooled steel flame tube and secondary air injection; (3) validation of the burner in the mGT at elevated pressure levels. The current study will present the results of phase 2. The hydrogen burner used in the project is based on a swirl-stabilized burner of TUB and was scaled to 36 kW thermal power at atmospheric conditions. The burner design features a variable swirl intensity, additional axial momentum of air in the mixing tube, a movable central fuel lance, and pilot nozzles at the front plate. Furthermore, the steel flame tube is exchangeable, which allows the evaluation of different dilution hole patterns and, thus, the variation of the ratio of primary and secondary air. The study presents temperature, pressure, and emission measurements. It is found that the flame can be operated over a large range of equivalence ratios and preheating temperatures up to 500 °C. As expected, the NOx emissions are mainly influenced by the local equivalence ratio, which can be controlled by the fuel mass flow or the dilution hole pattern in the flame tube. Furthermore, the results show a decrease of NOx when the power density is increased at constant equivalence ratios, and a rise of NOx during the fuel transition from natural gas to hydrogen. The results indicate certain differences to the findings of phase 1.
Synergetic and Performance Characteristics of a High-Speed Precooled Propulsion Concept
Authors: Chatzistefanou Athanasios , Tsentis Spyros , Kalfas Anestis
Published: August 2024

Precooled air-breathing cycles are promising candidates to power future high-speed flight as well as single-stage-to-orbit vehicles, due to their increased efficiency over contemporary propulsion systems and launch vehicles. These concepts usually feature complex interactions in the synergy of their thermodynamic cycles, which are not yet well understood, especially at off-design conditions. In this study, a performance model for a precooled, hybrid, air-breathing, rocket-cycle engine is developed for its air-breathing mode of operation. One-dimensional thermodynamic modeling is employed within a component-level approach, to evaluate the performance and operation of the cycle under investigation in the range of 1.35≤M∞≤5 and conditions of up to 26 km altitude. The model is validated quantitatively and qualitatively for both design and off-design conditions. The specific impulse Isp and specific thrust Fspec, as predicted by the model, agree within less than 5% for the design-point conditions at M∞ = 5. At off-design conditions, the model captures the trend of Isp and agrees within less than 1% with respect to the data for the maximum value of Isp. The maximum gross thrust Fgross point is predicted correctly at M∞=4. The fundamental operating principles and synergetic characteristics of the engine at design and off-design conditions are investigated and reported. Parametric analyses quantify the influence of the engine's parameters on the leading performance metrics. A model which does not feature a bypass duct is created and compared for the same inflow conditions and mission profile. It is found that the engine without the bypass duct exhibits reduced specific impulse which can be up to 32% lower at off-design conditions. In addition, the corresponding fuel mass flowrate to achieve the same mission is increased by a factor of 1.5. It is demonstrated that the overall trend of engine efficiency cannot be properly captured without modeling of the bypass duct, especially at the region of M∞<3.5, where the ramjet-like operation is critical. This highlights the importance of the bypass, which is typically neglected in the modeling of such high-speed, combined-cycle systems.
A High-Speed, High-Temperature, Micro-Cantilever Steam Turbine for Hot Syngas Compression in Small-Scale Combined Heat and Power
Authors: He Victoria , Van Herle Jan , Schiffmann Jürg
Published: August 2024

Coupling a biomass gasifier with a solid oxide fuel cell system through a high-temperature syngas compressor holds great promise to achieve low-emission, small-scale combined heat and power, since it reduces the number of heat exchangers and increases the system efficiency. However, due to the demanding operating conditions (high temperatures, toxic and explosive gases), electrical motors are not suitable to drive the syngas compressor. Therefore, a high-speed, small-scale cantilever steam turbine that can valorize the system's waste heat to power the compression is designed and developed. An iterative holistic process involving preliminary design, meanline analysis, commercial tools, and in-house codes is used for the design. The design is then numerically analyzed using computational fluid dynamics. The 2.8 kW cantilever steam turbine with a tip diameter of 21 mm runs up to 210 krpm at temperatures of 525 °C while being supported on dynamic steam-lubricated bearings. A low-reaction, full-admission design has been chosen to lower the steam consumption, the axial forces, and the turbine backface leakage. The turbine rotor is made of Ti6Al4V and coated for structural integrity and to withstand high temperatures. Despite the small scale of this design, the results obtained from the established correlations based on large-scale turbines yield a remarkable concordance with the results from the numerical analysis, in particular for the isentropic expansion efficiency prediction.
A High-Temperature, High-Speed, Oil-Free Syngas Compressor for Small-Scale Combined Heat and Power
Authors: He Victoria , Van Herle Jan , Schiffmann Jürg
Published: August 2024

For low-emission, small-scale combined heat and power generation, integrating a biomass gasifier with a downstream solid oxide fuel cell system is very promising due to their similar operating conditions in terms of temperatures and pressures. This match avoids intermediate high-temperature heat exchangers and improves system efficiency. However, to couple both systems, a high-temperature and oil-free compressor is required to compress and push the low-density, high-temperature biosyngas from the gasifier to the solid oxide fuel cell stack. The design and development of this high-temperature, high-speed, and gas-bearing supported compressor is presented in this work. A holistic iterative process involving preliminary design, meanline analysis using commercial tools and in-house models is used for the design, which is then numerically analyzed using computational fluid dynamics. The goal is to achieve a design with a wide operating range and high robustness that withstands extreme working conditions. The 727 W machine is designed to run up to 210 krpm to compress 18.23 kg h−1 of syngas at 350 °C and 0.81 bar. The centrifugal compressor has a tip diameter of 38 mm and consists of 9 backswept main and splitter blades. The impeller is made of Ti6Al4V and coated to prevent hydrogen embrittlement from the hot and highly reactive biosyngas. The results obtained from the established models suggest a good concordance with the results from numerical analyses, despite the high temperatures and small scale of this design.
Optimization of Smooth Straight-Through Labyrinth Seal Based on XGBoost and Improved Genetic Algorithm
Authors: Liu Hao , Li Guoqing , Kang Chenyang , Ruan Yunhong , Wang Ruofan , Lu Xingen
Published: August 2024

Improving the sealing performance of labyrinth seal is beneficial in reducing the loss of downstream components as well as improving the aero-engines' efficiency. Meanwhile, the optimization of labyrinth seal is more cost-effective than optimizing other components of aero-engines. Based on extreme gradient boosting (XGBoost) and improved genetic algorithm (GA), an automatic optimizer for smooth straight-through labyrinth seal is proposed. According to the ordering of feature importance, the ten selected geometric parameters of smooth straight-through labyrinth seals with two gaps (0.1 mm, 0.25 mm) are optimized when the axial length of labyrinth seal is limited. The optimization results show that the leakage rate of the optimized labyrinth seal with two gaps is 19.67% and 23.80% lower than the reference labyrinth seal, respectively. It is found that the decrease of fin height, fin angle, fillet radius, and fin width, and the increase of fin pitch are beneficial to improve the sealing performance of smooth straight-through labyrinth seal. The analysis of flow field reveals the reasons for the improvement of sealing performance due to the change of geometric parameters. However, it must be noted that the optimization effect decreases as the pressure ratio increases, primarily as the result of the increase in carry-over coefficient. This work provides a new approach to optimize smooth straight-through labyrinth seal.
Investigation of the Coupling Between the Dynamics of Vortical Structures and Flame Stability in Bluff-Body Premixed Combustion Using Extended Spectral Proper Orthogonal Decomposition
Authors: Khalifehei Morteza , Yalcinkaya Yagiz , Padilla-Montero Iván , Gungor Ayse Gul , Rodríguez Daniel
Published: August 2024

Large eddy simulation data of a bluff-body stabilized flame are analyzed using spectral proper orthogonal decomposition (SPOD) to investigate: (i) the role of flame-vortex interactions in the dominant flow dynamics and (ii) how the proper choice of the cross-spectral density (CSD) defining SPOD can assist in identifying the underlying dynamics. Bluff-body flame holders aim to achieve stable flames under lean premixed conditions to minimize pollutant emissions. The recirculation region induced by the body promotes the mixing of hot combustion products with unburnt gases, preventing the global blowoff. However, the coupling between the shear layers and flame-induced vorticity sources can result in large flow structures that either contribute to increased flame stability or exhibit features typical of the early stages of flame blowout. SPOD is a data-driven technique remarkably powerful in extracting low-dimensional models. For each frequency, it computes a basis of orthogonal modes that maximizes the content of a predefined CSD in the leading modes. By choosing physically relevant variables to construct the CSD, different physics can be explored, which is used here to investigate the coupled dynamics between the flame-induced baroclinic torque, vortical structures, and the temperature field. The results show that the vorticity and temperature fields exhibit low-dimensional dynamics characterized by a narrowband frequency and its harmonics; these dynamics are varicose oscillations of the flame region, governed by the baroclinic torque. Sinuous oscillations typical of wake instability for nonreactive flows are also present, suggesting a competition between them.
Compressor Surge Identification in Innovative Heat-Pump Systems Equipped by Vaned Diffuser Centrifugal Compressor
Authors: Niccolini Marmont Du Haut Champ Carlo Alberto , Silvestri Paolo , Reggio Federico , Traverso Alberto , Sishtla Vishnu
Published: August 2024

In the present energy scenario, heat pumps (HPs) are assuming an important role to improve energy efficiency in reversible cooling systems. In particular, in case of industrial size plants, centrifugal compressors are preferred with respect to other solutions; nonetheless, they are often subjected to variable operation and therefore they must withstand off-design conditions. For studying unstable operation of refrigerant closed-loop systems, Carrier provided the University of Genoa with a small size chiller rig equipped with an innovative high speed centrifugal compressor driven by a variable speed motor. This paper presents the vibro-acoustic signature analysis of such a closed-loop rig from a system perspective, mainly focusing on mechanical response of compressor casing. First, its vibro-acoustic characterization is conducted at on-design and stable operation. Afterwards, some surge transients are obtained by progressively closing some valves in plant feeding lines, and meanwhile vibro-acoustic signals are acquired at relevant plant locations to characterize system response just before instability onset. In this way, suitable surge precursors can be defined in incipient surge conditions for early surge detection in this kind of complex plants. Indeed, system dynamics is significantly affected by interposed volumes, and therefore the effect of heat exchangers in system response may be relevant. To this aim, system dynamics is analyzed in detail both in subsynchronous frequency range and in high frequency region to assess how its vibro-acoustic response varies when moving from stable conditions toward surge. Surge precursors are obtained by relying only on vibro-acoustic signals both in low and high frequency ranges in order to perform early surge detection in such chiller pilot system. The main advantage of the proposed approach is to exploit nonintrusive probes, which allow to define diagnostic indicators without interacting directly with the working fluid, therefore preserving system integrity and reliability.
Silurian ocean island basalt magmatism and Devonian–Carboniferous polymetamorphism: 100 million years in the Western Blue Ridge, USA
Authors: Yasar I. Dogancan , Miller Brent V. , Hames Willis E.
Published: August 2024

The tectonic configuration and evolution of southern Appalachian orogenic episodes are constrained, to a large extent, by knowledge of the timing and environment of pre- or syn-orogenic sediment deposition along with their subsequent thermal and deformational histories. The orogenic events that gave rise to regional folding and Barrovian metamorphism of the Western Blue Ridge (WBR) terrane are a classic example. We present new U-Pb and 40Ar-39Ar results bearing on the timing of magmatism and subsequent metamorphism of the Marble Hill Hornblende Schist (MHHS) of the WBR (southeastern USA). The schist is a key marker unit in the Murphy synclinorium, a central structure in the tectonic configuration of the WBR. The MMHS originated as basaltic volcanics overlying the Murphy Marble at the base of the Mineral Bluff Group. Ocean island basalt geochemistry and a zircon U-Pb age of ca. 437 Ma for the MHHS is consistent with plume-related volcanism in a Silurian remnant ocean basin of the Iapetus Ocean. Hornblende 40Ar-39Ar and rutile U-Pb ages for the MHHS are ca. 380–340 Ma and ca. 320 Ma, respectively, and record subsequent amphibolite facies metamorphism during Devonian Acadian orogeny and the deformation through regional folding and thrusting during the Carboniferous Alleghanian orogeny. The new age constraints for the MHHS require that “isograds” mapped in the region of the Murphy Belt are actually polymetamorphic mineral distributions that developed at least in part through post-Silurian tectonic events.
Newly discovered diamictite and cap carbonate couplet in the southern Alxa Block, northwestern China: Implications for stratigraphic correlation and Marinoan glaciation
Authors: Shao Dong , Han Yigui , Li Meng , Lu Lihui , Ju Pengcheng , Cao Xuyang , Hu Haiyan , He Jiajun , Zhao Guochun
Published: August 2024

Neoproterozoic glaciogenic diamictite and cap carbonate couplets have played a pivotal role in understanding glacial-interglacial cycles and establishing regional stratigraphic correlation. The Alxa Block in northwestern China preserves a sequence of Neoproterozoic diamictites along its southern margin, but the age and origin of the succession remain debatable due to the lack of discovery of cap carbonate. We report newly discovered cap carbonates that overlie the diamictites of the Shaohuotonggou Formation in the Longshoushan region in the southern Alxa Block. Based on detailed geological investigations, we identified massive diamictites, stratified diamictites, and cap carbonates in the lower part of the formation. The presence of ice-rafted dropstones, bullet-shaped and facetted clasts, glacial striations, and relatively low chemical index of alteration values of sedimentary matrix support a glaciogenic origin of the diamictites. The 2- to 2.6-m-thick cap carbonates are mainly composed of thinly laminated microcrystalline dolomites and show sheet cracks, cemented breccias, and tepee-like structures at the basal part of the unit. These features and their consistently negative δ13C values (−5.2‰ to −2.2‰) are characteristic of Marinoan-age cap carbonates (ca. 635 Ma). The quasi-continuous deposition of the massive diamictites, stratified diamictites, and cap carbonates suggests that the formation of this couplet was closely related to the Marinoan glaciation and subsequent deglaciation. We propose a three-stage depositional model for the glaciogenic succession and recommend that the diamictite and cap carbonate couplet in the Alxa Block provides a credible mark of the Cryogenian–Ediacaran boundary for further stratigraphic correlation and investigation.
Lawsonite eclogite records subduction rheology and slab detachment, Faro, Yukon-Tanana Terrane, Yukon Territory, Canada
Authors: Faber Carly , Rowe Christie D.
Published: August 2024

Lawsonite eclogites represent cold subduction in the rock record, and new localities provide rare natural field laboratories to investigate deep deformation processes. We present a new lawsonite eclogite locality near Faro, Yukon Territory, Canada, the first reported lawsonite eclogite locality of the Yukon-Tanana Terrane. The discovery indicates that mid- to Late Permian subduction in the Yukon-Tanana Terrane subducted cold material in an oceanic subduction zone, in contrast to most previous models. We define a pressure-temperature-deformation (P-T-d) pathway for the lawsonite eclogites using a combination of microstructures, mineral compositional mapping, crystal orientation mapping, and phase equilibrium modeling. Metamorphism in the Faro eclogites followed a clockwise pathway through the lawsonite eclogite facies, reaching peak pressures of 22–24 MPa at 525–550 °C. Rocks then exhumed to 14.5–16 MPa during heating to 630–655 °C. Crystallographic preferred orientations (CPOs) in omphacite developed dominantly by dissolution-precipitation creep and oriented grain growth concurrently with CPOs developed in glaucophane by a combination of dislocation- and dissolution-precipitation creep with oriented grain growth. We link this fabric and CPO development in omphacite and amphibole to lawsonite dehydration, slab decoupling, and initiation of exhumation of the eclogites, providing evidence that lawsonite dehydration plays a significant role in changes in subduction zone rheology.
Post-glacial stratigraphy and late Holocene record of great Cascadia earthquakes in Ozette Lake, Washington, USA
Authors: Brothers Daniel S. , Sherrod Brian L. , Singleton Drake M. , Padgett Jason S. , Hill Jenna C. , Ritchie Andrew C. , Kluesner Jared W. , Dartnell Peter
Published: August 2024

Ozette Lake is an ~100-m-deep coastal lake located along the outer coast of the Olympic Peninsula (Washington, USA); it is situated above the locked portion of the northern Cascadia megathrust but also relatively isolated from active crustal faults and intraslab earthquakes. Here we present a suite of geophysical and geological evidence for earthquake-triggered mass transport deposits (MTDs) and related turbidite deposition in Ozette Lake since ca. 14 ka. Comprehensive high-resolution bathymetry data, seismic reflection profiles, and sediment cores are used to characterize the post-glacial stratigraphic framework and examine paleoseismic evidence in the lacustrine sediments. Stacked sequences of MTDs along the steep eastern flanks of the lake appear to grade basin-ward from thick, chaotic, blocky masses to thin, parallel-bedded turbidite beds. The discrete turbidite event layers are separated by fine-grained (silt and clay) lake sedimentation. The event layers are observed throughout the lake, but the physical characteristics of the deposits vary considerably depending on proximity to primary depocenters, steep slopes, and subaqueous deltas. A total of 30–34 event deposits are observed in the post-glacial record. Radiometric dating was used to reconstruct a detailed sedimentation history over the last ~5.5 k.y., develop an age model, and estimate the recurrence (365–405 yr) for the most recent 12 event layers. Based on sedimentological characteristics, temporal overlap with other regional paleoseismic chronologies, and recurrence estimates, at least 10 of the dated event layers appear to be sourced from slope failures triggered by intense shaking during megathrust ruptures; the recurrence interval for these 10 events is 440–560 yr. Thus, Ozette Lake contains one of the longest and most robust geological records of repeated shaking along the northern Cascadia subduction zone.
Acupuncture for obesity: study protocol for a randomised controlled trial
Authors: Zhao Xinyu , Wang Yang , Li Xiaoyi , Wu Nianwei , Zhang Shanshan , Wu Shiyi , Hu Peiqun , Chen Ximei , Zhou Lei , Wei Aiming , Pan Chongsheng , Liu Yunlu , He Benxiang , Hu Yushi , Zhu Tianmin , Pan Xiong-Fei
Published: August 2024

Background

Obesity is a major public health issue in China and around the world. While acupuncture is often used in clinical practice, there is a lack of conclusive evidence for its weight-loss effect. Thus we will conduct a parallel, randomised, sham-controlled trial to evaluate the efficacy and safety of acupuncture for treating obesity.

Methods and analysis

A total of 160 eligible participants with obesity will be randomly assigned to the verum acupuncture group or sham acupuncture group at a ratio of 1:1. All participants will be treated three times a week for a duration of 12 weeks, and followed up for another 16 weeks. The primary outcome is the percentage change in body weight from baseline to Week 12. The secondary outcomes include body mass index (BMI), waist circumference (WC), body fat percentage (BF%), blood pressure, fasting blood glucose, insulin, glycosylated haemoglobin A1c, blood lipids, and physical functioning score on the Short Form 36 Health Survey. Other secondary outcomes including psychological and social functions will also be evaluated using thebody image scale, psychological function scale, and social function scale of the BODY-Q,Rosenberg Self-Esteem Scale,PatientHealth Questionnaire-9, and Dutch Eating Behaviour Questionnaire. BMI, WC, BF% and blood pressure will be evaluated atWeek0, 4, 8, 12 and 28. Other secondary outcomes will be measured atWeek0, 12 and 28, respectively. Adverse events will be recorded in detail during the trial.

Ethics and dissemination

Ethical approval of this trial was granted by the Ethics Committee of Chengdu Sport University (2023–102). Written informed consent will be obtained from study participants before enrolment. The findings will be disseminated through peer-reviewed journals.

Trial registration number

Chinese Clinical Trial Registry (ChiCTR2200062092).
Population-based study of factors associated with severe paediatric drowning events in Maryland
Authors: Macmillan Katherine , Hoops Katherine , Kudchadkar Sapna , Gielen Andrea C , McDonald Eileen M , Prichett Laura , Nasr Isam , Ryan Leticia Manning
Published: August 2024

Introduction

Paediatric drowning is an injury associated with significant morbidity and mortality.

Objective

The objective is to describe drowning trends, including associations with inpatient hospitalisation or fatality, in a state-wide paediatric cohort to inform prevention strategies.

Methods

In this retrospective cohort study using the Health Services Cost Review Commission database, we used International Classification of Diseases, Tenth Revision (ICD-10) codes to identify patients aged 0–19 years with an outpatient (including emergency department) or inpatient medical encounter following a non-fatal or fatal drowning event between 2016 and 2019. Descriptive statistics and logistic regression were used to summarise the data and evaluate associations with inpatient hospitalisation or fatality.

Results

There were 541 medical encounters for drowning events, including 483 non-fatal outpatient encounters, 42 non-fatal inpatient encounters and 16 fatal cases. Overall, most patients were boys, 0–4 years, white and lived in urban settings. White children accounted for 66% of encounters among those aged 0–4 years, whereas non-white children accounted for 62% of visits among those aged 10–19 years. Non-white children were more likely than white children to experience a fatal drowning (OR 3.6, 95% CI: 1.2 to 11.5). Adolescents were more likely than younger children to be hospitalised (OR 3.1, 95% CI: 1.6 to 6.5) and had higher charges in outpatient (p=0.002) and inpatient settings (p=0.003).

Discussion

Our study revealed high fatality rates among non-white children and high admission rates among adolescents.
What can healthcare organisations do to improve medical engagement? A systematic review
Authors: Perry Jen
Published: August 2024

Background

Medical engagement is linked to improved outcomes for staff and patients including a reduction in staff turnover. There are significant problems with recruitment and retention of doctors globally, it is, therefore, important to try to increase medical engagement within healthcare organisations. This systematic review aimed to review evidence from 2018 to 2023 from peer-reviewed journals on interventions to improve medical engagement and from this generate practical recommendations for healthcare organisations.

Method

A search strategy was developed and used across six databases alongside citation searching. Articles were screened to check whether they met the study criteria and were then critically appraised. The interventions were extracted and a thematic analysis, using an inductive approach, was undertaken.

Results

15 articles were found to have met the criteria, however, the studies were generally found to be of low-quality research evidence. The interventions from the articles were grouped into nine themes covering topics such as ‘Improvements to working conditions’, ‘Increasing support to doctors’ and ‘Rewards/incentives/recognition’.

Conclusion

The review generated a wide range of interventions which could be used to improve medical engagement, however, critical appraisal revealed that they were of low-quality evidence, so their effectiveness should be interpreted with some caution. The majority of the interventions were transferable to healthcare settings, with some limitations depending on the country. Several HR models were described as options for implementing these interventions within healthcare organisations. Further high-quality research is needed in this area.
Gender and sex differences in occupation-specific infectious diseases: a systematic review
Authors: Biswas Aviroop , Tiong Maggie , Irvin Emma , Zhai Glenda , Sinkins Maia , Johnston Heather , Yassi Annalee , Smith Peter M , Koehoorn Mieke
Published: August 2024

Occupational infectious disease risks between men and women have often been attributed to the gendered distribution of the labour force, with limited comparative research on occupation-specific infectious disease risks. The objective of this study was to compare infectious disease risks within the same occupations by gender. A systematic review of peer-reviewed studies published between 2016 and 2021 was undertaken. To be included, studies were required to report infectious disease risks for men, women or non-binary people within the same occupation. The included studies were appraised for methodological quality. A post hoc power calculation was also conducted. 63 studies were included in the systematic review. Among high-quality studies with statistical power (9/63), there was evidence of a higher hepatitis risk for men than for women among patient-facing healthcare workers (HCWs) and a higher parasitic infection risk for men than for women among farmers (one study each). The rest of the high-quality studies (7/63) reported no difference between men and women, including for COVID-19 risk among patient-facing HCWs and physicians, hepatitis risk among swine workers, influenza risk among poultry workers, tuberculosis risk among livestock workers and toxoplasmosis risk among abattoir workers. The findings suggest that occupational infectious disease risks are similarly experienced for men and women within the same occupation with a few exceptions showing a higher risk for men. Future studies examining gender/sex differences in occupational infectious diseases need to ensure adequate sampling by gender.
Tobacco retailer density and its association with birth outcomes in the USA: 2000–2016
Authors: Baggett Chris D , Richardson David B , Kuo Tzy-Mey , Rudolph Jacqueline E , Kong Amanda Y , Ribisl Kurt M , Golden Shelley D
Published: August 2024

Introduction

Significant progress has been made in reducing maternal exposure to tobacco smoke and subsequent adverse birth outcomes, however, reductions may require strategies that reduce the availability of tobacco retailers. In this study, we investigated the relationship between tobacco retailer density and birth outcomes across the USA and predicted the potential impact of a tobacco retailer density cap on these outcomes.

Methods

Annual US county (n=3105), rates of preterm birth, low birth weight, small-for-gestational age, all-cause infant mortality and sudden infant death syndrome (SIDS) were calculated using National Vital Statistics System data. Tobacco retailers were identified from the National Establishment Time-Series Database. We used Poisson regression to estimate the effect of capping retailer density at 1.4 retailers per 1000 population, controlling for county demographics and air pollution, using propensity score weighting.

Results

Tobacco retailer density was positively associated with most adverse birth outcomes. We estimate that a nationwide cap on tobacco retailer density, implemented in 2016, would have resulted in a reduction of 4275 (95% CI 2210 to 6392) preterm births, 6096 (95% CI 4421 to 7806) small-for-gestational-age births, 3483 (95% CI 2615 to 4378) low birthweight births, 538 (95% CI 345 to 733) all-cause infant deaths and 107 (95% CI 55 to 158) SIDS deaths in that year.

Conclusion

Higher rates of adverse birth outcomes were seen in counties with high tobacco retailer density compared with those with low density. These results provide further support for regulating tobacco retail density to reduce adverse health outcomes associated with tobacco use.
Sarcopenia: recent advances for detection, progression, and metabolic alterations along with therapeutic targets
Authors: Ali Syeda Roohina , Nkembo Augustine T. , Tipparaju Srinivas M. , Ashraf Muhammad , Xuan Wanling
Published: August 2024

Sarcopenia, a disorder marked by muscle loss and dysfunction, is a global health concern, particularly in aging populations. Sarcopenia is intricately related to various health conditions, including obesity, dysphagia, and frailty, which underscores the complexity. Despite recent advances in metabolomics and other omics data for early detection and treatment, the precise characterization and diagnosis of sarcopenia remains challenging. In the present review we provide an overview of the complex metabolic mechanisms that underlie sarcopenia, with particular emphasis on protein, lipid, carbohydrate, and bone metabolism. The review highlights the importance of leucine and other amino acids in promoting muscle protein synthesis and clarifies the critical role played by amino acid metabolism in preserving muscular health. In addition, the review provides insights regarding lipid metabolism on sarcopenia, with an emphasis on the effects of inflammation and insulin resistance. The development of sarcopenia is largely influenced by insulin resistance, especially with regard to glucose metabolism. Overall, the review emphasizes the complex relationship between bone and muscle health by highlighting the interaction between sarcopenia and bone metabolism. Furthermore, the review outlines various therapeutic approaches and potential biomarkers for diagnosing sarcopenia. These include pharmacological strategies such as hormone replacement therapy and anabolic steroids as well as lifestyle modifications such as exercise, nutrition, and dietary changes.
Search for a leptophobic doubly charged Higgs in same-sign four-lepton and six-lepton signatures in a left-right symmetric model
Authors: Ghosh Tathagata , Rahaman Rafiqul , Rai Santosh Kumar
Published: August 2024

We investigate the possibility of multi-lepton (four and six) signatures, including an exotic signature of same-sign four-lepton (SS4L) as signals of pair production of a doubly charged Higgs in the minimal left-right symmetric model, extended with two doublet scalars. The right-handed neutrino masses are generated in this model through a dimension-5 lepton-number violating operator allowing the triplet scalar interactions with leptons to become negligibly small. This leads to interesting six-lepton and SS4L signatures that can be observed at the high-luminosity phase of the Large Hadron Collider (HL-LHC) with almost no background for doubly charged Higgs with mass below 500 GeV.
Single axion-like particles production in the γγ channel at high energy muon colliders
Authors: Li Haitao , Wu Qiang , Zhang Guoqing
Published: August 2024

Axion-like particles (ALPs), which are pseudo-scalar particles, appear in various new physics models with the spontaneous global symmetry breaking. The difference between ALPs and axion models is that for the former both masses and couplings of ALPs are free parameters. It appears that the ALPs with masses above 1[Formula: see text]GeV are beyond the reach of low-energy accelerators, existing cosmological and astrophysical constraints, while high-energy colliders provide unique possibilities to explore such particles. With the establishment of the International Muon Collider Collaboration, muon colliders have been widely concerned. In general, ALPs are mainly produced at muon colliders through the [Formula: see text] annihilation and electroweak vector-boson-fusion (VBF) processes. In this paper, we study the prospect of the production of heavy ALPs with mass greater than 10[Formula: see text]GeV via the massless [Formula: see text]-fusion process at the multi-TeV muon collider. Focusing on the couplings of ALPs to the Standard Model gauge bosons, we obtain the excluding and discovering capabilities for ALPs at the 3[Formula: see text]TeV and 10[Formula: see text]TeV muon colliders. Our numerical results suggest that the multi-TeV muon collider may be more sensitive to ALPs with the mass of 35–400[Formula: see text]GeV than LHC, and can provide the possibility to search for ALPs with masses greater than 3[Formula: see text]TeV. In addition, we also discuss the effect of narrow width approximation on the ALP search sensitivity.
First-principles study of Ni-adsorption on non-metal atom-doped MoSe2
Authors: Su Dan , Liu Guili , Wei Ran , Ma Mengting , Yang Zhonghua , Zhang Guoying
Published: August 2024

In this paper, the effect of C, N and O atom doping of intrinsic MoSe2 on the adsorption capacity of Ni is investigated based on first-principle research methods. The aim is to analyze whether intrinsic MoSe2 can be doped and modified to improve its adsorption capacity of Ni so that it can be used as a new type of adsorbent material. By calculating and analyzing the energy band structure, density of states, differential charge and optical properties of each system, the conclusions are as follows: the O-doped MoSe2 system has the best adsorption capacity for Ni, and the adsorption capacities of the three systems are in the following order: O>N>C. The bandgap value of intrinsic MoSe2 adsorbed Ni-atom decreases, while the Fermi energy level of the C-doped MoSe2 adsorbed Ni-atom system is located in the valence band, which shows p-type doping. The differential charge of the system was analyzed and the charge transfer of the adsorbed system was increased by C, N and O atom doping, and the O-doped system had the strongest adsorption capacity for Ni. It was shown that the charge distribution between the system and the adsorbed Ni-atom changed considerably after atomic doping, and the bonds between the Ni-atom and the dopant atoms of the C-, N- and O-doped adsorption system were strongly ionic. Optical analysis reveals that C, N and O atom doping improves the charge binding ability of Ni-adsorbed MoSe2 material, which gives it a higher polarization rate and faster electric field response. The absorption of ultraviolet light is greatly enhanced, which can improve the efficiency of solar cells and convert solar energy into electricity more effectively. Overall, the Ni adsorption capacity of atomically doped MoSe2 is improved, indicating that doping can be an effective means to improve the adsorption of Ni-atom by intrinsic MoSe2. It is hoped that the research results in this paper can provide some theoretical guidance for the application of MoSe2 in optoelectronic devices.
Free-will arbitrary time adaptive chaos control for permanent magnet synchronous motor
Authors: Zhang Jinzhong , Wei Duqu
Published: August 2024

Permanent magnet synchronous motor (PMSM) is a multivariable and highly coupled nonlinear system, which is prone to chaotic behavior during actual operation. In order to suppress the chaotic behavior of the PMSM, this work designs a free-will arbitrary time adaptive controller based on the inverse step derivation, adaptive control theorem and Lyapunov stability theory. Firstly, the corresponding coordination transformations are designed according to the PMSM. Secondly, the bounded problem of the controlled system is analyzed by using the Lyapunov stability theory, and the free-will arbitrary time adaptive controller is designed by backstepping derivation. Finally, numerical simulation verifies that the designed controller quickly stabilizes the system state variables to the output signals and proves that the controller is free-will arbitrary time stable for all closed-loop signals.
Repeat, Reproduce, Replicate
Authors: Neville-Neil George V.
Published: August 2024

The pressure to publish versus the will to defend scientific claims.
Exploring the Effects of User-Agent and User-Designer Similarity in Virtual Human Design to Promote Mental Health Intentions for College Students
Authors: Feijóo-García Pedro Guillermo , Wrenn Chase , Gomes de Siqueira Alexandre , Ghosh Rashi , Stuart Jacob , Yao Heng , Lok Benjamin
Published: August 2024

Virtual humans (i.e., embodied conversational agents) have the potential to support college students’ mental health, particularly in Science, Technology, Engineering, and Mathematics (STEM) fields where students are at a heightened risk of mental disorders such as anxiety and depression. A comprehensive understanding of students, considering their cultural characteristics, experiences, and expectations, is crucial for creating timely and effective virtual human interventions. To this end, we conducted a user study with 481 computer science students from a major university in North America, exploring how they co-designed virtual humans to support mental health conversations for students
similar to them
. Our findings suggest that computer science students who engage in co-design processes of virtual humans tend to create agents that closely resemble them demographically—agent-designer demographic similarity. Key factors influencing virtual human design included age, gender, ethnicity, and the matching between appearance and voice. We also observed that the demographic characteristics of virtual human designers, especially ethnicity and gender, tend to be associated with those of the virtual humans they designed. Finally, we provide insights concerning the impact of user-designer demographic similarity in virtual humans’ effectiveness in promoting mental health conversations when designers’ characteristics are shared explicitly or implicitly. Understanding how virtual humans’ characteristics serve users’ experiences in mental wellness conversations and the similarity-attraction effects between agents, users, and designers may help tailor virtual humans’ design to enhance their acceptance and increase their counseling effectiveness.
Dried Zingiber officinale Alleviates Dehydroepiandrosterone‐Induced Ovarian Granulosa Cell Apoptosis via the Reactive Oxygen Species‐Mediated Pathway
Authors: Liu Yuan , Luo Xin , Jia Keran , Liu Shuang , Zeng Yongqiu , Lin Xiyuan , Lin Xinyue , Wan Ying , Liao Lishang , Su Hongwei , Yi Jingyan , Xing Jinshan
Published: August 2024

Polycystic ovary syndrome (PCOS), a prevalent reproductive endocrine disorder, frequently coincides with insulin resistance, lipid dysregulation, and cellular apoptosis. In this study, we aimed to evaluate the therapeutic potential of Dried Zingiber officinale (DZO), renowned for its antibacterial, antiviral, anti‐inflammatory, and antioxidant properties, in the context of PCOS. To this end, we induced a PCOS mouse model through the administration of dehydroepiandrosterone (DHEA) and a high‐fat diet (HFD), followed by DZO treatment to assess its effects on ovarian pathology, insulin resistance, and hormonal imbalances. The anti‐apoptotic effect of DZO on PCOS ovarian granulosa cells was confirmed through network pharmacological analysis, TUNEL staining, FITC‐PI staining, and protein blotting. Notably, DZO treatment significantly alleviated ovarian pathological changes in PCOS mice and normalized hormone levels, including testosterone, estradiol, and progesterone/follicle‐stimulating hormone ratios. Furthermore, our findings confirmed the anti‐apoptotic effect of DZO on PCOS ovarian granulosa cells. Mechanistically, DZO primarily exerted its therapeutic effects in PCOS by inhibiting apoptosis induced by the accumulation of reactive oxygen species (ROS). In conclusion, our study demonstrates the promising therapeutic role of DZO in the management of obese PCOS patients, particularly in reversing ROS‐mediated apoptosis in ovarian granulosa cells.
Detection of Staphylococcal Enterotoxins A and E and Methicillin Resistance in Staphylococcus aureus Strains From Moroccan Broiler Chicken Meat
Authors: Nacer Sabrine , Nassik Saâdia , El Ftouhy Fatima Zahra , Derqaoui Sophia , Mouahid Mohamed , Lkhider Mustapha
Published: August 2024

Foodborne epidemics have become a serious public health emergency worldwide. Foods of animal origin, in particular chicken meat, are considered to be potential vectors of pathogenic bacteria, particularly Staphylococcus aureus. This bacterium can be resistant in the form of methicillin‐resistant S. aureus (MRSA) or produce enterotoxins leading to food poisoning when ingested. This study is aimed at exploring the virulence genes in S. aureus responsible for producing enterotoxins (staphylococcal enterotoxin [SE] A [sea] and SE E [see]) and determining the prevalence of MRSA in raw broiler meat in the Casa‐Rabat region in Morocco. A quantitative (q) PCR (qPCR) assay, using specific primers for S. aureus (nuc) confirmation and detection of enterotoxin genes (sea and see), as well as the methicillin‐resistant gene (mecA), was employed. Our findings indicated that all tested strains were positively identified as S. aureus. Among them, one isolate (1/54) tested positive for the see gene (1.85%), while none carried the sea gene. Furthermore, the mecA gene, indicative of MRSA, was present in 12/54 of the isolates (22.22%). The potential presence of MRSA in Moroccan poultry meat underscores a public health risk. Thus, stringent measures are imperative to curtail the contamination and proliferation of this bacterium during the slaughtering process, underscoring the importance of continuing research into the prevalence of MRSA colonization among poultry slaughterhouse personnel.
PU‐GNN: A Positive‐Unlabeled Learning Method for Polypharmacy Side‐Effects Detection Based on Graph Neural Networks
Authors: Keshavarz Abedin , Lakizadeh Amir
Published: August 2024

The simultaneous use of multiple drugs, known as polypharmacy, heightens the risks of harmful side effects due to drug‐drug interactions. Predicting these interactions is crucial in drug research due to the rising prevalence of polypharmacy. Researchers employ a graphical structure to model these interactions, representing drugs and side effects as nodes and their interactions as edges. This creates a multipartite graph that encompasses various interactions such as protein‐protein interactions, drug‐target interactions, and side effects of polypharmacy. In this study, a method named PU‐GNN, based on graph neural networks, is introduced to predict drug side effects. The proposed method involves three main steps: (1) drug features extraction using a novel biclustering algorithm, (2) reducing uncertainity in input data using a positive‐unlabeled learning algorithm, and (3) prediction of drug’s polypharmacies by utilizing a graph neural network. Performance evaluation using 5‐fold cross‐validation reveals that PU‐GNN surpasses other methods, achieving high scores of 0.977, 0.96, and 0.949 in the AUPR, AUC, and F1 measures, respectively.
The Global Trends of Thyroid Cancer Research: A Scientometric Study
Authors: Ghojazadeh Morteza , Mobasseri Majid , Mostafaei Hadi , Asadizadeh-Azar Mahsa , Kabiri Neda , Kazemi Abdolhassan , Lotfi Alireza , Aletaha Reza , Akbari-Khoei Ali , Salehi-Pourmehr Hanieh
Published: August 2024

Cancer of the thyroid has become the fastest‐growing cancer among women in the past several decades. This study is aimed at using scientometric methods to identify research frontiers and development trends in the field of thyroid cancer (TC) research. We used the Scopus database to collect articles and reviews related to TC in November 2022. R software and Bibliometrix software package were used for scientometric analysis. More than 28,000 articles were obtained from Scopus using the defined specific keywords. The United States, France, and England published the most publications. Journal of Clinical Endocrinology and Metabolism and Cancer were found as the core journals in this field. Morris LGT, Sikora AG, and Davies L authored the most publications. National Cancer Institute, National Cancer Institute at NIH, and the University of Washington contributed the most publications. The most cited evidence was related to the articles of Bray (2018), Sung (2021), and Parkin (2005). Using scientometric analysis, this study mapped and visualized the knowledge landscape in the field of TC. The analysis showed that scientists in the field of TC are working collaboratively to tackle one of the most prevalent cancers in the world. This analysis showed that scientists in the field of TC are working with a scientific framework as a team to tackle one of the most common cancers in the world.