bluuebunny/crossref_metadata_2025 huggingface dataset:
Using population dynamics to count bacteriophages and their lysogens
Authors: Geng Yuncong , Nguyen Thu Vu Phuc , Homaee Ehsan , Golding Ido
Published: October 2023

Traditional assays for counting bacteriophages and their lysogens are labor-intensive and highly perturbative to the host cells. Here, we present a high-throughput infection method where all steps—cell growth, viral encounters, and post-infection recovery—take place in a microplate reader, and the growth dynamics of the infected culture are measured continuously using the optical density (OD). We find that the post-infection dynamics are reproducible and interpretable. In particular, the OD at which the culture lyses scales linearly with the logarithm of the initial phage concentration, providing a way of measuring phage numbers in unknown samples over nine decades and down to single-phage sensitivity. Interpreting the measured dynamics using a mathematical model for the coupled kinetics of phages and bacteria further allows us to infer the rates of viral encounters and cell lysis. Adding a single step of antibiotic selection provides the ability to measure the rate of host lysogenization. To demonstrate the application of our assay, we characterized the effect of bacterial growth rate on the propensity of lambda phage to lysogenizeE. coli. When infected by a single phage, the probability of lysogenization is found to decrease approximately exponentially with the host growth rate. In growing, but not in stationary, cells, the propensity to lysogenize increases ~50-fold when multiple phages co-infect the cell. These findings illuminate how host physiology feeds into the lysis/lysogeny decision circuit, and demonstrate the utility of high-throughput infection to interrogating phage-host interactions.
WITHDRAWN: Plasma GPI and PGD are associated with vascular normalization and may serve as novel prognostic biomarkers for lung adenocarcinoma: Multi-omics and multi-dimensional analysis
Authors: Liu Yiran , Wang Yanchi , Mao Liping , Hu Yang , Zhao Rongrong , Zhang Wendi , Xu Huiwen , Xu Buyun , Wu Yutong , Chen Qiong , Tao Xiaobo , Xu Shufan , Zhuang Xun , Lian Yulong , Lu Yihua , Zhang Lei , Tian Tian , Cui Jiahua , Tian Guangyu , Chu Minjie
Published: October 2023

Withdrawal Statement

The authors have withdrawn their manuscript owing to adjustments have been made to the content. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.
A set of circulating microRNAs belonging to the 14q32 chromosomic locus identifies two clinically and phenotypically different subgroups of individuals with recent onset Stage 3 type 1 diabetes
Authors: Sebastiani Guido , Grieco Giuseppina Emanuela , Bruttini Marco , Auddino Stefano , Mori Alessia , Toniolli Mattia , Fignani Daniela , Licata Giada , Nigi Laura , Formichi Caterina , Pugliese Alberto , Evans-Molina Carmella , Overbergh Lut , Tree Timothy , Peakman Mark , Mathieu Chantal , Dotta Francesco
Published: October 2023

Previous research has indicated that circulating microRNAs are linked to the onset and progression of type 1 diabetes mellitus (T1DM), making them potential biomarkers for the disease. In this study, we employed a multiplatform sequencing approach to analyze circulating microRNAs in an extended cohort of individuals recently diagnosed with T1DM from the European INNODIA consortium. Our findings revealed that a specific set of microRNAs located within the T1DM susceptibility chromosomal locus 14q32 distinguishes two distinct subgroups of T1DM individuals. To validate our results, we conducted additional analyses on a second cohort of T1DM individuals, independently confirming the identification of these two subgroups, which we have named Cluster A and Cluster B. Remarkably, Cluster B T1DM individuals, who exhibited increased expression of 14q32 miRNAs, displayed a different peripheral blood immunomics profile, possessed a lower T1DM risk HLA genotype, and showed better glycaemic control during follow-up visits compared to Cluster A individuals. Taken together, our findings suggest that this specific set of circulating microRNAs located in the 14q32 locus can effectively identify T1DM subgroups with distinct characteristics and different clinical outcomes during follow-up.

GRAPHICAL ABSTRACT

HIGHLIGHTS

Circulating miRNA profiles in individuals with newly diagnosed Type 1 Diabetes Mellitus (T1DM) can distinguish two subgroups: Cluster A and Cluster B.

miR-409-3p, miR-127-3p, and miR-382-5p are increased in the plasma of individuals in Cluster B.

Individuals in Cluster B showed lower IAA titers, a reduced prevalence of HLA risk genotype, and an improved glycaemic profile during the follow-up period.

Immunomic profiling revealed a reduced frequency of pro-inflammatory immune cells and a higher frequency of exhausted T lymphocytes among individuals in Cluster B.
Perioperative outcomes and platinum resistant recurrence in patients undergoing protocol based total parietal peritonectomy during interval cytoreductive surgery for advanced ovarian cancer- results of the TORPEDO study
Authors: Bhatt Aditi , Sinukumar Snita , Damodaran Dileep , Patel Ankita , Shaikh Sakina , Parikh Loma , Goswami Gaurav , Singh Anjali , Kammar Praveen , Mehta Sanket
Published: October 2023

Background and aim

The TORPEDO (CTRI/2018/12/016789) is the single-arm, prospective, interventional study evaluating the role of a total parietal peritonectomy (TPP) in patients undergoing interval cytoreductive surgery (iCRS). In this manuscript, we report the perioperative outcomes and platinum resistant recurrence (PRR) in 218 patients enrolled in the study.

Methods

A TPP was performed in all patients undergoing iCRS irrespective of the residual disease extent. HIPEC was performed as per the clinician’s discretion with 75mg/m2 of Cisplatin. Maintenance therapy was also used at the discretion of the treating clinicians.

Results

From 9thDecember 2018 to 31stJuly 2022 (recruitment complete), 218 patients were enrolled at 4 Indian centres. The median surgical PCI was 14 and a complete gross resection was achieved in 95.8%. HIPEC was performed in 130 (59.6%) patients. The 90-day major morbidity was 17.4% and 2.7% patients died within 90 days of surgery. Adjuvant chemotherapy was delayed beyond 6 weeks in 7.3%. At a median follow-up of 19m [95% CI 15-35m], 101 (46.3%) recurrences and 19 (8.7%) deaths had occurred. The median PFS was 22m [95% CI 17-35m] and the median OS not reached. Platinum resistant recurrence was observed in 6.4%. The projected 3-year OS was 81.5% and in 80 patients treated before may 2020, it was 77.5%.

Conclusions

The morbidity and mortality of TPP with or without HIPEC performed during iCRS is acceptable. The incidence was of PRR is low. Early survival results are encouraging and warrant conduction of a randomized controlled trial comparing TPP with conventional surgery.
Machine learning and biological validation identify sphingolipids as potential mediators of paclitaxel-induced neuropathy in cancer patients
Authors: Lötsch Jörn , Gasimli Khayal , Malkusch Sebastian , Hahnefeld Lisa , Angioni Carlo , Schreiber Yannick , Trautmann Sandra , Wedel Saskia , Thomas Dominique , Bouzas Nerea Ferreiros , Brandts Christian , Schnappauf Benjamin , Solbach Christine , Geisslinger Gerd , Sisignano Marco
Published: October 2023

Background

Chemotherapy-induced peripheral neuropathy (CIPN) is a serious therapy-limiting side effect of commonly used anticancer drugs. Previous studies suggest that lipids may play a role in CIPN. Therefore, the present study aimed to identify the particular types of lipids that are regulated as a consequence of paclitaxel administration and may be associated with the occurrence of post-therapeutic neuropathy.

Methods

High resolution mass spectrometry lipidomics was applied to quantify d = 255 different lipid mediators in the blood of n = 31 patients drawn before and after paclitaxel therapy for breast cancer treatment. A variety of supervised statistical and machine-learning methods was applied to identify lipids that were regulated during paclitaxel therapy or differed among patients with and without post-therapeutic neuropathy.

Results

Twenty-seven lipids were identified that carried relevant information to train machine learning algorithms to identify, in new cases, whether a blood sample was drawn before or after paclitaxel therapy with a median balanced accuracy of up to 90%. One of the top hits, sphinganine-1-phosphate (SA1P), was found to induce calcium transients in sensory neurons via the transient receptor potential vanilloid 1 (TRPV1) channel and sphingosine-1-phosphate receptors.SA1P also showed different blood concentrations between patients with and without neuropathy.

Conclusions

Present findings suggest a role for sphinganine-1-phosphate in paclitaxel-induced biological changes associated with neuropathic side effects. The identified SA1P, through its receptors, may provide a potential drug target for co-therapy with paclitaxel to reduce one of its major and therapy-limiting side effects.
PowerAI-CVD – the first Chinese-specific, validated artificial intelligence-poweredin-silicopredictive model for cardiovascular disease
Authors: Li Lifang , Chou Oscar Hou In , Lu Lei , Pui Hugo Hok Him , Lee Quinncy , Kaur Narinder , Wong Wing Tak , Chang Carlin , Liu Haipeng , Wai Abraham Ka Chung , Cheung Bernard Man Yung , Liu Tong , Tse Gary , Zhou Jiandong
Published: October 2023

Background

The main risk stratification tools for identifying high-risk individuals of cardiovascular disease (CVD) are based on Western populations. Few models are developed specifically for Asian populations and are not enhanced by artificial intelligence (AI). The aim of this study is to develop the first AI-powered quantitative predictive tool for CVD (PowerAI-CVD) incorporate physiological blood pressure measurements, existing diseases and medications, and laboratory tests from Chinese patients.

Methods

The study analysed patients who attended family medicine clinics between 1stJanuary 2000 and 31stDecember 2003. The primary outcome was major adverse cardiovascular events (MACE) defined as a composite of myocardial infarction, heart failure, transient ischaemic attack (TIA)/stroke or cardiovascular mortality, with follow-up until 31stDecember 2019. The performance of AI-driven models (CatBoost, XGBoost, Gradient Boosting, Multilayer Perceptron, Random Forest, Naïve Bayes, Decision Tree, k-Nearest Neighbor, AdaBoost, SVM-Sigmod) for predicting MACE was compared. Predicted probability (ranging between 0 and 1) of the best model (CatBoost) was used as the baselinein-silicomarker to predict future MACE events during follow-up.

Results

A total of 154,569 patients were included. Over a median follow-up of 16.1 (11.6-17.8) years, 31,061 (20.44%) suffered from MACE (annualised risk: 1.28%). The machine learningin-silicomarker captured MACE risk from established risk variables (sex, age, mean systolic and diastolic blood pressure, existing cardiovascular diseases, medications (anticoagulants, antiplatelets, antihypertensive drugs, and statins) and laboratory tests (NLR, creatinine, ALP, AST, ALT, HbA1c, fasting glucose, triglyceride, LDL and HDL)). MACE incidences increased quantitatively with ascending quartiles of thein-silicomarker. The CatBoost model showed the best performance with an area under the receiver operating characteristic curve of 0.869. The CatBoost model basedin-silicomarker shows significant prediction strength for future MACE events, across subgroups (age, sex, prior MACE, etc) and different follow-up durations.

Conclusions

The AI-powered risk prediction tool can accurately forecast incident CVD events, allowing personalised risk prediction at the individual level. A dashboard for predictive analytics was developed, allowing real-time dynamic updates of risk estimates from new data. It can be easily incorporated into routine clinical use to aid clinicians and healthcare administrators to identify high-risk patients.

Graphical Abstract
Downstream characteristics of extended flat plate trailing edge on S809 wind turbine blade under various turbulent intensities
Authors: S. Mano , S. Nadaraja Pillai
Published: October 2023

Purpose

This study aims to investigate the effect of downstream characteristics of S809 wind turbine blade with various extended flat plate (EFP) configuration. Wind farms are recently modified to improve the power production through placing number of wind turbines and locations.

Design/methodology/approach

A series of wind tunnel experiments were carried out to evaluate the downstream wake characteristics of the S809 airfoil attached with various EFP (EFP, A = 0.1C, 0.2C and 0.3C) at various angles of attack corresponding to free stream velocity Reynolds number (Re) = 2.11 × 105 and various turbulence intensity (TI = 5%, 7%, 10% and 12%).

Findings

For the S809 wind turbine blade attached with EFP, the downstream velocity ratio decreases with increasing in angle of attack and the velocity deficit decrease with increasing turbulence intensity (TI) up to TI = 10%. The wake intensity for the S809 wind turbine blade and S809 airfoil with 10% of chord EFP performs the same for each downstream location.

Practical implications

Placing the wind turbine in the wind park next to another wind turbine poses a potential challenge for the park power performance. This research addresses the characteristics of the downstream turbulence intensity profile modified with the EFP in the wind turbine blade which improves the downstream characteristics of the turbine in the wind park.

Originality/value

The downstream velocity ratio decreases with increasing angle of attack and the velocity deficit decrease with increasing turbulence intensity (TI) up to TI = 10%.
Clinical utility of a cytomegalovirus‐specific T cell assay in assessing the risk of post‐prophylaxis cytomegalovirus infection and post‐treatment relapse
Authors: Dioverti Maria Veronica , Bhaimia Eric , Yetmar Zachary A. , Melendez Dante P. , Misner Lori , Beito Elaine , Deziel Paul J. , Theel Elitza S. , Razonable Raymund R.
Published: October 2023

Introduction

Cytomegalovirus (CMV) causes significant morbidity in solid organ transplant recipients (SOTR). Measuring cell‐mediated immunity (CMI) may inform the risk of CMV infection after antiviral prophylaxis and predict relapse after CMV treatment.

Methods

We serially assessed CMV CMI using the QuantiFERON‐CMV assay (QF‐CMV; Qiagen, Germantown, MD) in two cohorts of SOTRs: during valganciclovir prophylaxis and during treatment of CMV viremia. Results of CMI were correlated with post‐prophylaxis CMV infection and post‐treatment relapse, respectively.

Results

Only one (4.2%) of 24 CMV D+/R‐ patients demonstrated positive QF‐CMV by the end of valganciclovir prophylaxis. Four (16.6%) patients developed post‐prophylaxis CMV infection; all four had undetectable QF‐CMV at end of prophylaxis. Among 20 patients treated for CMV infection, 18 (90%) developed QF‐CMV levels >.2 IU/mL by end of antiviral treatment and none developed CMV relapse. In contrast, the single patient who relapsed after completing treatment had a CMV CMI <.2 IU/ml (p = .0036).

Conclusion

Since CMV D+/R‐ SOTRs are unlikely to develop adequate CMV CMI while receiving valganciclovir prophylaxis, the utility of CMV CMI monitoring for risk stratification during time of prophylaxis had limited value. Conversely, CMV CMI testing may be a useful marker of the risk of CMV relapse after antiviral treatment.
Potassium‐lowering effects of sodium zirconium cyclosilicate in the early post‐transplant period
Authors: Shockey William , Wiegel Joshua J. , Parajuli Sandesh , Garg Neetika , Swanson Kurtis J. , Mandelbrot Didier A.
Published: October 2023

Problem

Hyperkalemia is a serious condition among intra‐abdominal transplant recipients, and the safety and efficacy of sodium zirconium cyclosilicate (SZC) for its management during the early post‐transplant period are not well‐established.

Methods

Adults who received at least one 10‐g dose of SZC within 14 days after an intra‐abdominal transplant between January 2020 and July 2022 were included in our study. The primary outcome was the change in potassium (K+) levels following the first SZC dose. Other analyses explored adjunctive potassium‐lowering therapies, potential gastrointestinal complications, and patient subgroups based on therapy and transplant type.

Results

Among the recipients (n = 46), 11 were kidney recipients, 26 were liver recipients, seven were simultaneous liver/kidney recipients, and two were simultaneous pancreas/kidney recipients. The mean time to first dose post‐transplant was 7.6 (±4) days, and the mean change in serum K+ after the initial SZC dose was −.27 mEq (p = .001). No gastrointestinal complications were observed following the SZC dose. The mean increase in serum bicarbonate was .58 mEq (p = .41) following the first dose of SZC. Four kidney recipients required dialysis following the SZC dose.

Conclusion

This study represents the largest investigation on the use of SZC in transplant recipients. A single 10‐g dose of SZC reduced serum K+ levels in all subgroups, while the use of adjunctive K+‐lowering therapies did not provide additional reduction beyond the effects of SZC. Importantly, no gastrointestinal complications were observed. These findings suggest that SZC may be a safe and promising therapeutic option for hyperkalemia management following solid organ transplantation.
Successful prenatal treatment with continuous chronic maternal hyperoxygenation therapy in hypoplastic left heart in two pregnancies: Case report
Authors: Bolluk Gokhan , Oztarhan Aylin , Vural Cagdas , Oztarhan Kazim , Gedikbasi Ali
Published: October 2023

Maternal hyperoxygenation (MH) has been studied as a diagnostic tool to evaluate pulmonary vasculature and as a treatment option to improve the growth of fetal left heart in fetuses with left‐sided cardiac defects. Chronic maternal hyperoxygenation (CMH) therapy leads to an improvement in fetal pulmonary blood flow resulting in an enhanced venous return to the left heart with increased gestational age. With this manipulation it is anticipated to augment blood flow directed remodeling of the left heart structures and to improve left heart growth spanning from the mitral valve to the aortic isthmus. However, there are concerns about CMH therapy with regard to fetal complications with growth restriction and fetal brain development. Now, with two successful cases we try to discuss this fetal treatment option and related concerns.
The unintended energy efficiency gain from tax incentives for investment: Micro‐evidence from quasi‐natural experiments in China
Authors: Song Yijia , Li Xitao , Liu Ruoxi , Peng Xin
Published: October 2023

In light of the economic recession in the post‐pandemic era, countries have implemented a wide array of fiscal stimulus measures as a means of addressing the prevailing economic challenges but often neglect to consider the consequences of these stimuli on the environment. Therefore, it is crucial for the government to take environmental considerations into economic stimulus packages, aiming to achieve a sustainable “green recovery.” Using China's value‐added tax (VAT) reform as a quasi‐natural experiment, we find that VAT incentives have significantly improved the firm's energy efficiency through factor substitution and technological progress, indicating that tax incentives are beneficial to economic stimulus and energy saving. In addition, we find that energy market distortions play a significant negative moderating role, which weakens energy efficiency gained from the VAT incentives. Furthermore, heterogeneity analysis shows that the improvement of energy efficiency is concentrated in non‐state, high‐capital intensity, and high financing‐dependent firms. According to our findings, policymakers should have a thorough understanding of the potential of tax incentives for investment as a policy tool for achieving a “green recovery” as long as the energy market is efficient.
Hummocky sedimentary structures within rippled beds due to combined orbital waves and transverse currents
Authors: Wu Xuxu , Carling Paul A. , Parsons Daniel
Published: October 2023

Hummocky cross‐stratification is commonly observed in the marine offshore transition to lower shoreface environments. However, to date, the origins of hummocky cross‐stratification and its associated hummocky bedforms and hydrodynamic processes remain controversial and enigmatic. In the present study, a large‐scale flume experiment was conducted to study the formation of hummocky bedforms. In the central test area of the flume, combined flow with water waves, with period of 2 s and velocity of 0.34 m s−1, progressed at a right angle to a current with velocity of 0.17 m s−1, whereas a wave‐alone condition pertained upstream and downstream of the test area. The combined‐flow ripples in the test area had smaller dimensions than wave ripples, but their cross‐section geometries were very similar. Most importantly, the experimental results, for the first time, revealed that humps occur with lengths up to approximately 40 mm beneath combined flow ripples. The formation of these structures appears to relate to the enhanced turbulence for the combined flow, because the turbulence kinetic energy for combined flow was ca 50% higher than that under the wave‐only condition. Moreover, the observed small‐scale humps in the present experiment had comparable cross‐section geometries with hummock‐like bedforms previously reported in laboratories and fields under storm conditions. Additionally, these humps could scale up to large‐size hummocks under waves with longer period and faster velocity than the present conditions. The present experiment indicates that waves perpendicular to a current do generate hummock‐like structures in association with ripples and therefore provide a new perspective for future study of the origins of hummocky cross‐stratification.
Implicit Attitudes and Terror Management: Pilot of Implicit Association Test as a Means of Measuring Death-Thought Accessibility
Authors: Wong Norman C. H. , Massey Zachary
Published: October 2023

Terror management theory (TMT; Greenberg, Pyszczynski, & Solomon, 1986) has been extensively tested and applied in a variety of contexts. One of the major criticisms of TMT is that there are methodological issues with assessing some of the proposed processes within the theory, such as activation of death thought accessibility. The present study provides an initial test of a proposed alternative for measuring death thought accessibility using an image-based implicit association test instead of the traditional word fragment completion task used in a majority of TMT research. An experiment was carried out with 200 undergraduate students using a 2 (mortality salience: Yes or no) x 2 (social/fiscal conservatism: Low or high) between-subjects design. Results provided partial empirical support for the use of an IAT-based measure for death thought accessibility relying on color images. The IAT-based measure outperformed the traditional word fragment completion task at discriminating between mortality and non-mortality salient participants in terms of death thought accessibility.Moreover, this study also tested the mortality salience hypothesis to determine whether mortality salience activates cultural worldview defenses following a brief delay. Specifically, participants with differing political ideologies were asked to evaluate an editorial in support of the Muslim ban. Results found that after being reminded of their death, participants with strong levels of conservatism reported more positive attitudes toward the Muslim ban, relative to those in the control condition (i.e., non-mortality salient). Implications of the findings for this study as well as directions for future research are discussed.
Interface Characterization of Hybrid M21 Composites Through DCB and ENF Experiments and Numerical Predictions
Authors: Seamone Andrew A. , Lin Shiyao , Waas Anthony M. , Ranatunga Vipul P.
Published: October 2023

The technological advancement of carbon fiber reinforced polymers (CFRPs) has enabled innovative and complex use of the composites in the aerospace industry. Due to the time and cost of performing numerous physical experiments, finite element (FE) modeling tools for CFRP damage evolution and characterization are necessary. Interlaminar delamination is a structurally significant damage event in composites. This study investigates DCB and ENF experiments to characterize the fracture toughness of hybrid M21 CFRPs containing both unidirectional tape and woven lamina. The results of this study are combined with previous studies to define the interface properties of tape-tape interfaces, weave-weave interfaces, and hybrid interfaces with varying ply angle orientations. The experiments are recreated using cohesive modeling within a finite element framework to numerically characterize the cohesive strength and fracture toughness for each interface combination. This information lays the groundwork for future numerical predictions of structural configurations manufactured using M21 hybrid composites.
Effect of Curvature on Dynamic Response of Dyneema Composite Panel Under Extreme Loading: A Numerical Study
Authors: Kumar Vivek , Sankrityayan Rohit , Chawla Anoop , Dubey Devendra K.
Published: October 2023

Ultra-molecular weight polyethylene (UHMWPE) composites are the first choice for protective systems due to their inherent characteristics. These composites are widely used in bulletproof jackets as ceramic backing and enhanced combat helmets (ECH). While the ballistic performance of UHMWPE composites is well-researched, their response to blasts has not been extensively studied. Numerical analysis is used to evaluate the impact of the geometric curvature of Dyneema HB26 composite panels when exposed to extreme loading conditions. This analysis helps to determine the behavior and performance of the composite panels under these conditions and provides insight into their suitability for use in such applications. The results of the analysis can be used to optimize the design of the composite panels and ensure that they meet the necessary safety and performance requirements for the specific application. Simulations were carried out using the Multi-Material Arbitrary Lagrangian-Eulerian (MM-ALE) method in the LS-Dyna software. A parametric study was conducted for varying curvatures of the composite panel with four different thicknesses using a validated finite element framework. The outcomes were analyzed and compared for mid-point deflection and number of damaged layers. This study helps to improve the performance of composite panels in critical defense protection systems using appropriate geometric curvature.
Dynamic Aeroelastic Response of Camber Morphing Aircraft
Authors: Soneda Kensuke , Tsushima Natsuki , Yokozeki Tomohiro , Imamura Taro
Published: October 2023

Morphing technology has been intensively studied in the last decades. Camber morphing is one of the most popular and effective types of morphing, and its aerodynamic advantages have been demonstrated. Although its aeroelasticity has been studied in previous research, the coupling between its aeroelasticity and the flight dynamics of the overall aircraft has not been investigated well. This study aims to understand the influence of the aeroelasticity of morphing control surfaces on the flight dynamics of the aircraft. For this objective, an aeroelastic flight simulation framework that can consider camber morphing is developed. For the structural model, finite shell elements are used to capture the behavior of the camber morphing structures. For aerodynamics, an unsteady vortex lattice method is used to estimate the unsteady aerodynamic loads efficiently. A rigid-body flight dynamics is coupled with the structural and aerodynamic model to construct the aeroelastic flight simulation framework. The flight motions of the aircraft with morphing elevators are simulated under open-loop control. The results demonstrated that the aeroelastic response of morphing elevators differs depending on the stiffness of the morphing structure. It is also shown that this leads to the different gusts that the aircraft with morphing elevator experiences severe altitude changes.
High Resolution Experimental Study of Damage Initiation in Cross-Ply Laminate Using Digital Volume Correlation
Authors: Rojas Sanchez J. Fernando , Waas Anthony M.
Published: October 2023

The damage initiation mechanisms of a single edge notched cross-ply laminate are studied using a Digital Volume Correlation (DVC) analysis. The experimental results are used to verify an SD2M [1] model of the same problem. Using material properties found in the literature, the initial stiffness and the non-linearity of the force-strain curve were verified. The predicted crack density evolution of the model resembled closely that observed from Digital Image Correlation results. Although the ultimate load predicted by the model was within the experimental spread, it was non-conservative relative to the average. Another discrepancy between the model and experimental data was observed in the order in which the damage modes initiate and the points in the load-strain curve at which they happen. The procedure followed in this study demonstrates the potential of the DVC data collected for model verification.
A Refined Rotordynamics Model Analysis for Variable Thickness Rotors and Rotating Disks
Authors: Rubino Andrea , Cinefra Maria , Filippi Matteo
Published: October 2023

In industrial sector, rotating disks are widely used for engineering applications, for instance turbojet engines or steam turbines, and they are usually designed with non-uniform thickness in radial direction in order to improve stress and displacement fields and to reduce weight and rotational inertia. In this paper, a refined Finite Element Method (FEM) based on the Carrera Unified Formulation (CUF) is extended to evaluate the vibration characteristics of rotors with variable thickness. Using Lagrange-like polynomial Expansions (LE), the Node-Dependent-Kinematics (NDK) approach of this model is exploited: the geometry of the rotor is discretized into a finite number of 1D beam elements along the axis where the LE elements allow to develop refined displacement theories over the cross section of the beam; in addition, the NDK approach allows to discretize the rotating disks in a smooth way, accounting for the variable thickness of the considered elements. The governing equations are derived using the Hamilton’s Principle and solved through the Finite Element Method combined with the 1D CUF beam theory. Different numerical examples are investigated to illustrate the capabilities of the presented technique. The results represent the starting point to study the rotordynamics model, including the rotating effects such as the geometrical stiffening, the spin softening and the Coriolis contribution.
Predicting Stress in Structures Using Convolutional Neural Networks: the Case for 2D Plates
Authors: Truhn Ryan , Masoumi Masoud
Published: October 2023

Aeronautical structures are subjected to various loadings and damage initiators, such as bird strikes, which can reduce their lifespan. High internal stresses can contribute to potential failures. Therefore, high-fidelity modeling methods, such as finite element analysis (FEA), are used to study these structures under various loading conditions to design more resilient systems. However, these methods are computationally expensive and time-consuming, especially for large projects. Reliable, efficient techniques that can analyze the performance of these structures can improve the design process and reduce the risk of incidents. As an attempt to reduce analysis time, we propose using deep neural network models, specifically an encoder-decoder based convolutional neural network (CNN), to predict stress distribution in a structure based on geometry, external loadings, and boundary conditions. To implement this technique, we study stress distribution in 2D plates with different geometries and loading conditions using a Python script and FEA software. The script creates plates with unique conditions and runs FEA to obtain stress data, which is used to train and test the CNN model. The results of our analysis show good accuracy for stress field predictions and offer a reliable, fast technique for analyzing engineering structures. This method can be modified to study stress fields under various loading conditions for more complex structures in a fraction of the time it would take the FEA software to run the required simulations.
Investigations on Natural Frequency Shifts of a Cantilever Beam With a Spherical Void Defect
Authors: West Jeremy , Folden Trevor , O’Connor Dennis
Published: October 2023

Additive manufacturing methods, specifically metal 3D printing techniques are being used to allow intricacies of design never-before possible with traditional machining methods. Nevertheless, while a great deal of research has investigated the characteristics of cracks and defects in traditionally manufactured parts, far less work has examined the dynamic signatures associated with defects common to metal 3D printed parts. This paper investigates the dynamic signatures correlated with internal ablations in an additively manufactured, metal, cantilever beam. A mathematical model is developed to define the second area moment of a rectangular cantilever beam in the presence of a spherical void. Through the direct integration method, an explicit solution for stiffness is determined for a defected beam.
Architected Cellular Materials for Aerospace Components Design and Manufacturing
Authors: Rastegarzadeh Sina , Huang Jida , Wang Jun
Published: October 2023

The design of high-performance, lightweight materials has always been challenging in aerospace structural design (e.g., aircraft ailerons, flaps, and rudders). Sandwich panel composites with lattice cores are widely used in aerospace applications. This paper presents an inverse design optimization framework for sandwich structures with implicitly represented architected cellular unit cells. Specifically, cellular materials are implicitly represented (described by functions) as building blocks in the core structure design. A core topology optimization problem is formulated based on functionalities (compliance and thermal conductivity) in this paper. Lastly, the optimized delicate design is directly converted into digital slices for additive manufacturing, which avoids memory-expensive solid model conversion. The proposed design framework is validated in two aerospace design case studies. Experimental results demonstrate the effectiveness of the proposed optimization algorithm and STL-free scheme for additive manufacturing.
Fabricating Machine Elements Using Hydrogel-Infused Additive Manufacturing (HIAM)
Authors: Saigal Anil , Velling Seneca Jackson , Dhawan Akash , Azcona Baez Maria , Nocum Miguel , R. Greer Julia
Published: October 2023

Additive manufacturing (AM) of metals can enable rapid development of functional parts of complex geometry, with potential applications in the aerospace, automotive, and biomedical fields [1–3]. Typical metal additive manufacturing techniques are based on expensive laser melting or sintering processes which are often highly anisotropic, limiting the development and use of these methods. Furthermore, few additive manufacturing techniques focus on high temperature materials, ceramics, and fabrication of machine elements. The recent introduction of Hydrogel-Infusion Additive Manufacturing (HIAM) may reduce some of these barriers, enabling potential applications in high performance metal and ceramic devices and components. The HIAM process involves 3D printing a polyethylene oxide (PEO) photo-resin using vat polymerization, immersing the polymer in a metal salt solution which allows ionized metal cations to bond to the polymer backbone, followed by calcination to combust the polymer leaving a metal oxide that takes the same functional structure as the original polymer. Finally, the metal oxide is reduced using a forming gas (95% N2/5% H2) to give a metal product that maintains a scaled-down version of the complex as-printed architecture. This technique enables architected features with microscale resolution by use of a single photoresin simply by varying post-processing conditions. As a first step in the fabrication of machine elements and devices, this paper outlines an attempt to fabricate springs made from silver metal via HIAM. Silver nitrate is infused into an additively manufactured polymer spring structure. Based on the relative differences in the standard free energy of the oxides, Silver Oxide (AgO) is readily reduced to metallic silver under a single thermal processing step: calcination/reduction at 500°C without the need for forming gas. A variety of analytical techniques confirm HIAM processing obeys chemical kinetics of single-step calcination and reduction in accordance with literature and results in fabricated components of low microstrain (8.40E−7 ± 2.78E−9) crystalline silver with average crystallite size of 514.95 ± 5.32 Å and lattice parameter of 4.09 ± 5.23E−5 Å. Thermal analyses such as Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) elucidate the mass loss and reactions that occur during the furnace processing. Springs were subjected to quasi-static and cyclic loading using a Dynamic Mechanical Analyzer (DMA). A range of ∼2–20 N/mm stiffness was measured in unloading for different coil diameters and produced springs show consistency of part stiffness following compaction under cyclic loading.
Nonlinear Response of Contact Interface With Nanoscale Fractal Roughness Under Harmonic Excitation for Jointed Structures
Authors: Sun Yunyun , Wu Bing , Wu Shijing , Li Hongguang
Published: October 2023

Rough interfaces inevitably exist between precision mechanical parts for aerospace jointed structures. The roughness of the contact surface varies from microscale to nanoscale and exhibits self-similarity characteristics. Since the computational time of molecular dynamics (MD) simulation is generally less than microseconds, the steady-state vibration response of contact interfaces with nanoscale roughness is hard to obtain. Considering the nanoscale roughness of the surface morphology, the present work provides a theoretical method for analyzing the steady-state vibration of contact interface under harmonic excitation by combining the molecular dynamics simulation with the multi-scale method. The surface morphology is constructed from the atomic level, and the contact model of the nanoscale roughness interface is established. The fitting relationship between the normal contact force and the equivalent displacement is obtained. Accordingly, the mathematical equation of the contact vibration of the rough interface is derived. Variation of the natural frequency with the initial displacement is studied, and the amplitude-frequency response of the rough contact interface in steady-state vibration is revealed. Results show that jointed structures with nanoscale rough morphology exhibit nonlinearity in contact behaviors. The natural frequency decreases as the initial deflections deviate from the static equilibrium position. The amplitude jump phenomenon of the rough contact interface is observed under harmonic excitation, and a rougher interface corresponds to a stronger nonlinearity of amplitude-frequency dependence. Reducing the fractal roughness or increasing the fractal dimension of the contact interface may narrow down the excitation frequency range of the main resonance.
A Review of Analytical Models for Determining the Behavior of Metallic Tubular Structures Submitted to Axial Crushing
Authors: Anand Shreyas , Alderliesten René , Castro Saullo Giovani Pereira
Published: October 2023

This paper reviews analytical models proposed by Abramowicz et al.[1, 2] and Stefan et al.[3] for the axial crushing of metallic tubular structures with square and circular cross-sections. First, a database of experiments for square and circular tubes was created based on the literature. Subsequently, the predictions obtained using these analytical models were compared against the database of experiments to determine the accuracy of these analytical models. The database of experiments was also compared against some results generated using Finite-Element Method (FEM). Furthermore, the sensitivity of the analytical models to various material and geometrical parameters was studied to determine the influence of these parameters on the mean crushing force.

Both models were found to be highly sensitive to the thickness of the tubular structures. It was observed that the models proposed by Abramowicz et al.[1, 2] showed better agreement with experimental results, although an over-prediction was observed for square tubular structures made of materials with a significant difference between the values of yield and ultimate stress. The model proposed by Stefan et al.[3] slightly over-predicted for square tubes and showed reasonable accuracy for circular tubes.
Diagnostic value of the vascular index measured by superb microvascular imaging for evaluating breast tumors: a meta-analysis
Authors: Luo JingJing , Li Tao , Liu Yutong
Published: October 2023

Aim: This meta-analysis aims to assess the accuracy of superb microvascular imaging (SMI) using the vascular index (VI) in the diagnosis of breast tumors.Material and methods: PubMed, Web of Science, Embase, Cochrane Library and Scopus were searched for relevant literature by two researchers until March 14, 2023. The Stata Version 16.0 software was utilized to compute the pooled values for sensitivity (Sen), specificity (Spe), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odd ratios (DOR). Heterogeneity among the included literature was assessed using the I2 statistic and Q test. Conducting influence analysis was used to ensure the robustness of the pooled conclusions and the Deeks’ funnel plot asymmetry test to assess publication bias. We also performed the summary receiver operating characteristic (SROC) curve.Results: Six studies included 1200 breast lesions. The ultimate results in the VI of SMI are as follows: The pooled Sen was 0.80 (95% confidence interval(CI), 0.75–0.85), the pooled Spe was 0.68 (95% CI 0.63–0.74), the pooled PLR was 2.54 (95% CI 2.07–3.12), the pooled NLR was 0.29 (95% CI 0.22–0.38), the pooled DOR was 8.91 (95% CI 5.62–14.13), and the area under the SROC (AUC) was 0.81.Conclusion: The application of SMI using VI may have the potential to benefit the patients and represents a valuable quantitative parameter of SMI for the diagnosis of breast neoplasms.
How Societal Forces of Change Are Transforming Youth Physical Activity Promotion in North America
Authors: Szeszulski Jacob , Faro Jamie M. , Joseph Rodney P. , Lanza Kevin , Lévesque Lucie , Monroe Courtney M. , Pérez-Paredes Elsa A. , Soltero Erica G. , Lee Rebecca E.
Published: October 2023

Background: Climate change, increasing recognition of institutionalized discrimination, and the COVID-19 pandemic are large-scale, societal events (ie, forces of change) that affect the timing, settings, and modes of youth physical activity. Despite the impact that forces of change have on youth physical activity and physical activity environments, few studies consider how they affect physical activity promotion. Methods: The authors use 2 established frameworks, the ecological model of physical activity and the youth physical activity timing, how, and setting framework, to highlight changes in physical activity patterns of youth in North America that have resulted from contemporary forces of change. Results: North American countries—Canada, Mexico, and the United States—have faced similar but contextually different challenges for promoting physical activity in response to climate change, increasing recognition of institutionalized discrimination, and the COVID-19 pandemic. Innovative applications of implementation science, digital health technologies, and community-based participatory research methodologies may be practical for increasing and sustaining youth physical activity in response to these forces of change. Conclusions: Thoughtful synthesis of existing physical activity frameworks can help to guide the design and evaluation of new and existing physical activity initiatives. Researchers, practitioners, and policymakers are encouraged to carefully consider the intended and unintended consequences of actions designed to respond to forces of change.
Whole-genome sequences of
Bipolaris bicolor
,
Curvularia hawaiiensis
,
Curvularia spicifera
, and
Exserohilum rostratum
isolated from rice in Burkina Faso, France, Mali, and Pakistan
Authors: Kaboré Kouka Hilaire , Kassankogno Abalo Itolou , Adreit Henri , Ravel Sebastien , Charriat Florian , Diagne Diariatou , Lebrun Marc-Henri , Tharreau Didier
Published: October 2023

Different fungal species of the
Pleosporaceae
family infect rice, causing similar symptoms. Reference genomic sequences are useful tools to study the evolution of these species and to develop accurate molecular diagnostic tools. Here, we report the complete genome sequences of
Bipolaris bicolor
,
Curvularia hawaiiensis
,
Curvularia spicifera,
and
Exserohilum rostratum
.
Inference and forecasting phase shift regime of COVID-19 sub-lineages with a Markov-switching model
Authors: Noh Eul , Hong Jinwook , Yoo Joonkyung , Jung Jaehun
Published: October 2023

The occurrences and domination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are still crucial factors for determining the coronavirus disease 19 (COVID-19) policies. We collected weekly Phylogenetic Assignment of Named Global Outbreak sub-lineages, naming genetically distinct lineages of SARS-CoV-2, including variants of concern, in the United Kingdom, South Africa, South Korea, Denmark, Germany, the United States, and worldwide. This study included 12,296,756 samples of the max share of the sub-lineages from the 33rd week of 2020 to the 40th week of 2022. This study conducted a two-state Markov-switching model to estimate the probability of the phase shift state and predicted the probability of each regime with the Hamilton filter and Kim’s smoothing algorithm. We discovered different weekly patterns based on dominant SARS-CoV-2 variants in target area. Due to differences in containment policies and outbreak waves, we observed a time lag in dominant variants in these countries. Using the inferred probability of the phase shift regime for forecasting, it showed significant probabilities that the stable phase will still be stable in the next week. It also showed significant probabilities that the unstable phase will still be unstable in the next week. Our findings present the probability of observing the phase shift regime each week. Until a new SARS-CoV-2 variant occurs, the regime tended to stay with a low probability of phase shift regime. When a new SARS-CoV-2 variant would occur, the regime would immediately react and change the probability. We propose the Markov-switching model to determine COVID-19 policies and predict SARS-CoV-2 variants.

IMPORTANCE

Using regime-switching models, we attempted to determine whether there is a link between changes in severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) variants and infection waves, as well as forecasting new SARS-Cov-2 variants. We believe that our study makes a significant contribution to the field because it proposes a new approach for forecasting the ongoing pandemic, and the spread of other infectious diseases, using a statistical model which incorporates unpredictable factors such as human behavior, political factors, and cultural beliefs.