bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of magnetic and non-magnetic nanoparticles with Newtonian/non-Newtonian base fluids over a nonlinear stretching sheet
Authors: Jabeen Kanwal , Mushtaq Muhammad , Muntazir Rana Muhammad Akram
Published: February 2023

An unsteady mixed convectional boundary layer flow of a Casson nanofluid having magnetic ( Fe3 O4) and non-magnetic ( Al2 O3) nanoparticles suspension within two different types of base fluids, water (Newtonian) and sodium alginate (non-Newtonian), which incorporates viscous dissipation effects over a nonlinear stretching sheet with magnetic field effects. Some suitable non-dimensional similarity transformations are applied to convert the governing coupled nonlinear partial differential equations into a set of ordinary differential equations and then solved by using differential transformation method in association with Pade-approximation. A comparison has been made with already published results to assure the validity and reliability of the computational results, good agreement is found between the current and previous studies. The impacts of different physical parameters active on flow, temperature, and nanoparticle concentration have been discussed both numerically and graphically. The impact of radiation, internal heat sink/source, viscous, and ohmic dissipation was discussed for magnetic and non-magnetic nanofluid categories. We have also presented the tabular results of various emerging parameters to discuss the nature of skin friction, Nusselt, and Sherwood numbers. It was observed that performance of non-Newtonian (sodium alginate) fluid in heat and mass transfer is slightly better than Newtonian (water) based fluid but no major difference was seen in heat and mass transfer when comparison was made with magnetic and non-magnetic nanoparticles.
Innovative modeling strategy of wind resistance for platoon vehicles based on real-time disturbance observation and parameter identification
Authors: Dong Jiachen , Gao Qinhe , Li Jianqiu , Li Jingkang , Hu Zunyan , Liu Zhihao
Published: February 2023

Variable inter-vehicle distances influence significantly the wind resistance of platoon vehicles due to the sheltering of airflow. Accurate air drag estimation is extremely important for platoons in scenarios like energy-oriented driving and high-precision tracking. Most aerodynamic researchers have performed qualitative analysis of wind resistance for equally inter-spaced platoons, while the quantitative description of wind resistance variation with coupled inter-vehicle distances is rare. In addition, data measured through offline wind tunnel experiments, Computational Fluid Dynamics (CFD) simulations, or road tests via fuel consumption calibration for a period of time is unsynchronized, which may be unconvincing for real air drag estimation on road. Aiming at the quick and accurate approximation of platoon wind resistance, this paper proposes a novel and universal modeling strategy combining offline CFD simulation, online air drag observation, and real-time parameter identification. The variation characteristics of air drag with distance of a longitudinal platoon consisting of three homogeneous C-class Notchback cars are analyzed by CFD simulation. With appropriate data processing, a well-designed basis function is summarized. Then a novel wind resistance separation method combining Back-Propagation Neural Network (BPNN) and Extended State Observer (ESO) is proposed. Using the observed data stored in experience memory, the hybrid optimization method via particle swarm optimization (PSO) and gradient descent with momentum (GDM) is employed to identify the model parameters toward high accuracy and global optimality. Results of Hardware-In-the-Loop (HIL) experiment show that the proposed modeling strategy realizes effective real-time observation and accuracy description; the developed approximation model can describe the platoon wind resistance with continuous and coupled inter-vehicle distances, with the RMSE less than 11.4%.
Effect of tantalum addition on the mechanical properties of tungsten/tantalum composite thin films
Authors: Konuru S Lakshmi Kanth , V Umasankar , Sarkar Biswanath , Sarma Arun
Published: February 2023

Tungsten (W) when used as a plasma-facing material (PFM) in a tokamak will face harsh neutron radiation and high-temperature fluctuations. Due to its ductile-to-brittle transition temperature (DBTT), W behaves as a brittle material in lower temperatures and thus helps in propagating cracks easily resulting in dust formation and failure of material. In this study, an attempt has been made to improve the ductility, hardness, and toughness of W thin films by adding tantalum (Ta) to it, resulting in composite thin films. W/Ta composite thin films deposited on reduced-activation ferritic martensitic steel (RAFM) steel by RF magnetron sputtering method are compared with W thin films deposited on the same substrate. Taguchi orthogonal array is used to get the best properties for the composite thin films and nanoindentation technique is used to evaluate the mechanical properties of developed thin films. With the least hardness of 7.19 Gpa, composite film hardness is 452% lesser than the maximum hardness of (39.54 Gpa) W films. The reduction in hardness for composite thin films has not depleted the toughness as the Ef/Es ratio is higher than cracking threshold of 1.3. The maximum plastic energy absorbed for yield by composite films during nanoindentation is (1710 mN nm) 14% higher than W thin film (1500 mN nm), indicating the composite film is a ductile and tougher than the W film.
Comparison of adhesive joint strength of laser fabricated dimple textured Al–Mg alloy in different environment
Authors: Prakash Shashi
Published: February 2023

Joining of aluminium alloys using adhesives has got tremendous applications in aviation, marines, and unmanned aerial vehicles. Surface preparation plays a crucial role in the adhesive joining of two surfaces. In this research work, the nanosecond fibre laser was used to create dimple-shaped textures on aluminium–Mg alloy (AA5754). Dimple-shaped textures were created under three different atmospheric conditions. Experiments were performed in open-air conditions, under static water conditions, and under flowing water conditions. Texture depths differed by varying the scanning speed of laser beam. Texture pitch was also varied at two different levels, that is 300 [Formula: see text]m and 400  [Formula: see text]m in both texturing directions. Two different scanning speeds of 2.5 and 5 mm/s of the laser beam were investigated. Surface contact angle of each sample was evaluated using a goniometer to measure surface hydrophobicity/ hydrophillicity. Surface roughness and dimensions of dimples were measured using a digital microscope. Scanning electron microscopes were used to evaluate the morphology of textured surfaces. An epoxy-based adhesive (partite) was uniformly spread over textured zones and samples for standard tensile tests were prepared as per ASTM. Shear lap tensile tests were carried out to evaluate the shear lap strength of each joint on a universal testing machine. Surfaces prepared in static water conditions and flowing water conditions resulted in completely different morphology compared to open-air processing. It was observed that dimple patterns fabricated under flowing water conditions had the highest bonding strength among all the three processing environments.
High-dynamic intelligent maneuvering guidance strategy via deep reinforcement learning
Authors: Zhao Sibo , Zhu Jianwen , Bao Weimin , Li Xiaoping
Published: February 2023

Aiming at the coordination between maneuvering penetration and high-precision guidance under complex flight missions of high-velocity vehicle, the manuscript studies a three-dimensional high-dynamic intelligent maneuvering guidance strategy based on optimal control and deep reinforcement learning (DRL). A three-dimensional attack–defense model is established, and maneuver guidance mission is decomposed into longitudinal and lateral directions. In the longitudinal direction, maneuvering model with the instantaneous miss distance as the control variable is constructed, and the maximum value principle is employed to obtain the optimal maneuver duration and start timing. In the lateral direction, Markov decision process model of maneuver guidance is proposed by synthesizing the guidance error and miss distance of encounter point, and the reward function is designed by considering maneuver and guidance performance. The DRL method is used to learn and train the maneuver strategy, and the training process is improved as well. The simulation results show that the intelligent maneuvering guidance strategy can improve the penetration performance, reduce influence of maneuver flight on the guidance accuracy, and ensure the adaptability under changeable flight missions.
Impact of the ending position of controllable speed casing on the flow stability in a transonic compressor rotor
Authors: Zhao Jiayi , Wu Wanyang , Zhong Jingjun
Published: February 2023

The structure of casing treatment has a significant influence on the stability expansion effect. The ending position of the rotatable ring is one of the important structural parameters in the controllable speed casing. The impact of ending position of the rotatable ring rotating at the same speed as the rotor on the stability expansion and stability expansion mechanism was studied in this paper. The results show that, when the ending position of rotatable ring expands downstream in the range of 20% to 60% axial chord length, because of the improvement in the tip leakage vortex trajectory and main flow/leakage flow interface, the stability expansion effect rises gradually. The further downstream expansion of ending position from 60% axial chord length, however, has a slight impact on tip flow, bringing out a steady stability expansion effect around 52.5%. The best stability expansion effect of ending position occurs at 60% axial chord length where the stable operating margin increases by 53.5%.
Hepatocyte-derived Microparticles as Novel Biomarkers for the Diagnosis of Deep Venous Thrombosis in Trauma Patients
Authors: Zang Xinwei , Su Yu , Zhang Wenjie , Cao Xiangyu , Li Chunyan , Lu Shan , Zhao Huiru , Chen Yuying , Liang Cuiying , Wu Jun
Published: February 2023

Venous thromboembolism is a common complication following trauma. We investigated the dynamics of plasma microparticles (MPs) levels and explored their potential as biomarkers of deep vein thromboembolism (DVT) after trauma. A total of 775 patients with traumatic fractures were recruited in this nested study. About 106 trauma patients (53 DVT subjects and 53 age-, sex-, and fracture site-matched non-DVT subjects) and 53 healthy volunteers met the enrollment criteria. MPs were characterized by transmission electron microscope, nanoparticle tracking analysis, and western blotting. Circulating levels of MPs were measured using a flow cytometer. Meanwhile, routine laboratory parameters were examined in all patients. Compared to non-DVT patients, DVT patients had higher circulating phosphatidylserine (PS) + MPs, hepatocyte-derived MPs (HMPs), PS + HMPs, and platelet-derived MPs (PMPs). Notably, PS + HMPs had the best predictive value for DVT diagnosis in trauma patients (area under the curve [AUC] 0.8939, 95% CI 0.8326 to 0.9552), which was superior to d-dimer (AUC 0.5881). The Hepatic Procoagulant Index combined plasma levels of PS + HMPs and albumin, increasing the AUC to 0.8978 (95% CI 0.8396 to 0.9561). This is the first study that addressed circulating PS + HMPs are promising biomarkers with high performance in diagnosing DVT. The Hepatic Procoagulant Index is a potential predictor of DVT in trauma patients.
‘The festival is ours’: Power dynamics of community participation in the Alter do Chão Film Festival
Authors: Póvoa Débora
Published: February 2023

Although festivals are often promoted as opportunities for community empowerment, power dynamics during festival organization might hinder such potential. To discuss this issue, this article examines the Alter do Chão Film Festival (FestAlter), an originally collaborative project in the touristic village of Alter do Chão, Brazil. Through 16 interviews with festival stakeholders, the article unveils the changing power dynamics within the organization of the festival, and how these impacted the event's goals of community participation. I argue that the organization of this event moved from union to rupture among festival stakeholders – a trajectory caused by managerial divergences regarding the meaning of community participation and a lack of understanding of the history, culture and socioeconomic circumstances of Alter do Chão, an Amazonian village marked by enduring legacies of colonial exploitation.
Varieties of White Working-Class Identity
Authors: Knowles Eric D. , McDermott Monica , Richeson Jennifer A.
Published: February 2023

The present work demonstrates that, contrary to popular political narratives, working-class White Americans are far from monolithic in their class identities, social attitudes, and political preferences. Latent profile analysis is used to distinguish three types of identity in a nationally representative sample of working-class Whites: Working Class Patriots, who valorize responsibility, embrace national identity, and disparage the poor; Class Conflict Aware, who regard social class as a structural phenomenon and ascribe elitist attitudes to higher classes; and Working Class Connected, who embrace working-class identity, sympathize with the poor, and feel disrespected because of the work they do. This identity typology appears unique to working-class Whites and is associated with distinct patterns of attitudes regarding immigration, race, and politics, such that Class Conflict Aware and Working Class Connected Whites are considerably more progressive than are Working Class Patriots. Implications for electoral politics and race relations are discussed.
A two-part measurement error model to estimate participation in undeclared work and related earnings
Authors: Arezzo Maria Felice , Arima Serena , Guagnano Giuseppina
Published: February 2023

In undeclared work research, the estimation of the magnitude of the phenomenon (i.e., the amount of income and/or the percentage of workers involved) is of major interest. This has been done either using indirect methods or by means of ad hoc surveys such as the Eurobarometer special survey on undeclared work, our motivating study. The extent of undeclared work can be measured by means of two different outcomes: the event of working off-the-book (binary variable) and, when the event occurs, the amount of earnings deriving from the undeclared activity (continuous variable). This setup has been typically modeled via the so called two-part model: a binary choice model for the probability of observing a positive-versus-zero outcome and then, conditional on a positive outcome, a regression model for the positive outcome. We propose an extension of the two-part model that goes in two directions. The first regards the measurement error that, given the very nature of undeclared activities, is most likely to affect both the outcomes of interest. The second is that we generalize the linear regression part of the model to allow individual-level means. We also conduct an extensive simulation study to investigate the performance of the proposed model and compare it with traditional approaches.
Praxis of cross-cultural social work practice (CCSWP): A critical discourse analysis of graduate student and faculty perspectives on cultural competence and relevant constructs
Authors: Lee Eunjung , Johnstone Marjorie , Kourgiantakis Toula , Hu Ran , Leung Vivian
Published: February 2023

To examine how social work students and faculty perceive and embody cultural competence, we conducted five focus groups with graduate students ( N = 16) and faculty members ( N = 10) from Canadian schools of social work. We interrogated how different theoretical frameworks related to cross-cultural social work practice (CCSWP) have been circulated and reified in social work education, and how certain dominant frameworks have been translated to embodied cross-cultural interactions in social work practice. To examine the praxis of CCSWP, which is often subtle and embedded in the semantics of languages and discourses, we were informed by critical theories of power, language, and discourses to analyze the data. The interview transcripts of both student and faculty focus groups showed similar dominant discursive patterns: (1) critiquing the conceptual use of cultural competence, (2) having a preference for terms such as cultural humility, cultural safety, or other constructs, and (3) describing the embodied practice of these constructs mainly as a general practice and omitting cross-cultural work. Participants differed in their expressed opposition to cultural competence and the exact terms they preferred as an alternative. Overall, participants discursively changed from a critical debate on semantic and conceptual differences between these constructs to negating them altogether as meaningless, effacing the very notion of cross-cultural social work and its embodied practice. In the end, cultural competence was discounted as both oppressive and anti-oppressive, a position which is reflected in the contested scholarship on cultural competence.
Damage detection, quantification, and localization for resonant metamaterials using physics-based and data-driven methods
Authors: Zhu Yi-Chen , Cantero Chinchilla Sergio , Meng Han , Yan Wang-Ji , Chronopoulos Dimitrios
Published: February 2023

Resonant metamaterials have attracted significant research interest in mechanical and acoustic engineering with applications in the fields of sound and vibration control thanks to their integrated tuned mass dampers. One prevailing issue regarding industrial application of such structures is the high probability of local damage for their resonating parts. Accurate and efficient health state estimation methods for resonant metamaterials are therefore urgently required. In particular, the quantification and localization of damaged resonators represent key pieces of information for the operator of a structural asset. This work presents for the first time an investigation into quantifying and identifying damaged oscillators in a resonant metamaterial based on the measured frequency response function (FRF) data. Both data-driven and physics-based methods are implemented and corresponding results are exhibited. Manufacturing-induced structural uncertainty is quantified through physical measurements and taken into account in this work. It is demonstrated that such uncertainty may have a rather significant impact on the response of 3D printed resonant metamaterials, leading to difficulties vis-a-vis damage quantification. The proposed theoretical developments are able to properly account for such uncertainties, providing probabilistic estimation indices for the existing damage level and location. Both simulated and experimental case studies are presented to validate the two proposed methodologies and comparisons are also exhibited and discussed.
International Politics and the Subnational Allocation of World Bank Development Projects
Authors: DiLorenzo Matthew
Published: February 2023

Temporary United Nations Security Council (UNSC) members receive more World Bank projects. I consider the potential for UNSC status to influence aid allocation within recipient countries. While strategically important recipients might gain greater discretion over the internal distribution of aid, no clear evidence establishes whether World Bank aid tends to succumb to political pressures within countries. I examine whether political favoritism within countries varies with UNSC status and find little evidence for a connection. While cross-national lending may follow politics, subnational allocation seems to be unrelated to international politics, which has important implications for the efficacy of Bank assistance.
Diffracting Structure/Agency Dichotomies, Wave/Particle Dualities, and the Citational Politics of Settler Colonial Scholars Engaging Indigenous Studies Literature
Authors: Rosiek Jerry , Adkins-Cartee Mary
Published: February 2023

Building on Karen Barad’s philosophy of science, this paper offers a diffractive reading of quantum indeterminacy with/across the classic structure/agency dichotomy in social science scholarship. It highlights key parallels between the metaphysics of indeterminacy in both the physical and social sciences. In the course of this analysis, we draw upon relevant Indigenous studies literature. These citations are integrated into the diffractive analysis, both as a source of important and potentially transformative insight and as a performative illustration of enactment of political responsibility under conditions of ontological indeterminacy. The inclusion of the Indigenous studies citations raises questions about how to avoid problematic practices of appropriation and/or erasure. Instead of resolving this question, we will dwell within the indeterminacy it reveals and the responsibility for constructive action it brings into focus.
The smart-home study: A feasibility study to pilot the use of smartphone technology to identify environmental falls risk factors in the home
Authors: Leung Ka Ho Marco , Brandis Susan
Published: February 2023

Introduction

While occupational therapy home assessments are effective to identify environmental falls risk factors, patients may not receive these services due to workforce distribution and geographical distances. Technology may offer a new way for occupational therapists to conduct home assessments to identify environmental fall risks.

Objectives

To (i) explore the feasability of identifying environmental risk factors using smartphone technology, (ii) develop and pilot a suite of procedures for taking smartphone images and (iii) examine the inter-rater reliability and content validity between occupational therapists when assessing smartphone images using a standardised assessment tool.

Method

Following ethical approval a procedure was developed and participants recruited to submit smartphone images of their bedroom, bathroom and toilet. Two independent occupational therapists then assessed these images using a home safety checklist. Findings were analysed using inferential and descriptive statistics.

Results

Of 100 volunteers screened, 20 individuals participated. A guideline for instructing patients to take home images was developed and tested. Participants averaged 9.00 minutes (SD 4.401) to complete the task, whilst occupational therapists took approximately 8 minutes to review the images. The inter-rater reliability between the two therapists was 0.740 (95% CI: 0.452–0.888).

Conclusion

The study found that use of smartphones was to a large extent feasible and conclude that the use of smartphone technologies is a potential complimentary service to traditional home visits. The effective prescription of equipment in this trial was identified as a challenge. The impact on costs and potential falls incidents remains uncertain and more research is warranted in representative populations.
Research on the influence of a micro-groove-orifice structure and its layout form on the static characteristics of aerostatic journal bearings under a high gas supply pressure
Authors: Cui Wei , Li Shusen , Zhu Bailin , Yang Fei , Chen Bao
Published: February 2023

To solve the problems of a low gas supply pressure and low load capacity of traditional orifice-compensated aerostatic journal bearings (OCAJBs), this paper presents the design of a double-row gas supply micro-groove-orifice aerostatic journal bearing (MGOAJB). By establishing new governing equations and introducing the SST k- ω turbulence model, the influence of the micro-groove-orifice (MGO) structure and its layout form on the static characteristics of aerostatic journal bearings under a high gas supply pressure are studied. It is found that under high gas supply pressure, the MGO structure can significantly improve the load capacity and stiffness and reduce the gas consumption of the MGOAJB compared with the OCAJB. With additional MGO structures in the eccentric direction of the spindle, the load capacity and stiffness of the bearing increase substantially, and the gas flow also increases. The layout direction of the MGO has a prominent influence on the static characteristics of the MGOAJB. Axial MGOs have a higher load capacity and stiffness and lower gas flow. The accuracy of the simulation method is verified by experiments. This study provides a theoretical basis and method for the design of aerostatic journal bearings under a high gas supply pressure.
An innovative design of mega shaft boring machine (SBM) cutterhead based on TRIZ and AD theory
Authors: Xiao Jing , Liu Feixiang , Yang Mei , Ke Wei , Liu Dong , Lin Laikuang
Published: February 2023

Cutterhead is the key component of the mega shaft boring machine (SBM), whose complex structure and huge size lead to high manufacturing difficulty and cost, and its reliability is difficult to guarantee under huge loads. It is difficult to design the cutterhead only referring to the existing small horizontal tunnel boring machine cutterhead. In order to brainstorm innovative ideas, the paper incorporates the TRIZ into AD to address the following issues. Firstly, engineering conflicts in designing process are eliminated by TRIZ tools to generating innovative ideas. Then, the decomposition of functional requirements and design parameters are employed based on independence axiom of AD, transferring the abstract ideas into concrete design solutions. Moreover, fuzzy comprehensive evaluation is adopted to choose a better design scheme from alternatives of critical component. Finally, the feasibility and practicality of the proposed approach has been demonstrated through case study of designing a novel mega SBM cutterhead. The cutterhead structure is significantly improved with embedded movable cutter boxes, which can excavate step by step to reduce the driving torque, and the manufacturing and transportation cost has been greatly reduced. The method can help designer to innovative design the key components of large-scale underground tunneling equipment.
The inpatient costs related to revascularization of lower extremity artery disease in terms of amputation and mortality rates
Authors: Alptekin Gulen S , Erkul Sinan , Akgul Engin , Cekirdekci Ahmet
Published: February 2023

Objective

With the initial utilization of endovascular treatment options in 1970s, the number of procedures performed for lower extremity artery disease (LEAD) both with open surgical (OS) and endovascular (EV) treatment increased, but this did not result in a decrease in the number of amputations. The burden of LEAD still constitutes a huge proportion among the health care costs over the world.

Methods

The patients who admitted to our clinic between October 2014 and December 2019 with LEAD and required revascularization were enrolled. The total hospitalization costs related to LEAD were registered and divided into two groups as care costs and medical supplies costs.

Results

181 procedures were performed to 133 patients. Mean age was 63.98 ± 11.65 and 115 (86.5%) patients were male. Mean follow-up period was 31.19 ± 17.99 months (95% CI). The most frequent comorbidities were diabetes mellitus (DM) ( n = 86, 66.2%) and active smoking ( n = 59, 44.4%). Total costs and medical supplies costs were increased in EV group when compared with OS group ($4347.26 ± 3352.96, $3339.28 ± 3459.53 p = .005 v.s. $3318.67 ± 2874.55,$904.42 ± 1209.97 p < .001, respectively). Care costs were increased in OS group when compared with EV group ($2434.85 ± 2641.89 v.s. $1028.56 ± 1397.77 p < .001). The highest total, medical supplies, and care costs were determined in EV + OS group ($13071.32 ± 13717; $6784.91 ± 8332.04; $6286.41 ± 7652.12, respectively).Graft/wound infection related and amputation related costs were 21% of all costs. Amputation-free survival was 71.42% (95% CI) with 21 total amputations. There were linear correlations between mortality and amputation ( p = .002); also between mortality and cost ( p = .001).

Conclusions

In mid-long-term period, the care costs are increased with OS; however, EV treatment significantly increases the medical supplies and total costs. The increase in cost is correlated with poor outcome. Although the comorbidities and risk factors of these patients lead the clinicians to perform more challenging endovascular approaches, in mid-long-term period, particularly failed endovascular procedures are not promising in terms of outcomes and costs. We consider that the best-fit therapy on time is cost-effective, life and extremity-saving either, by avoiding deleterious effects of severe ischemia, such as severe pain, tissue loss, and related major adverse cardiaovascular events.
Evaluation of frequency, severity, and independent risk factors for recurrence of disease activity after fingolimod discontinuation in a large real-world cohort of patients with multiple sclerosis
Authors: Cerdá-Fuertes Nuria , Nagy Sara , Schaedelin Sabine , Sinnecker Tim , Ruberte Esther , Papadopoulou Athina , Würfel Jens , Kuhle Jens , Yaldizli Özgür , Kappos Ludwig , Derfuss Tobias , Décard Bernhard F.
Published: February 2023

Background:

Clinical and radiological signs of recurring disease activity (RDA) have been described in patients with multiple sclerosis (pwMS) after discontinuation of fingolimod (FGL).

Objective:

To describe frequency, severity and potential risk factors for RDA after FGL discontinuation in a large real-world cohort of pwMS.

Methods:

Post-FGL RDA was defined as evidence of clinical and/or radiological activity within 6 months after FGL discontinuation. Relapses with Expanded Disability Status Scale increase ⩾2 points and/or magnetic resonance imaging (MRI) activity with at least five cerebral gadolinium-enhancing lesions and/or ⩾6 cerebral new T2 lesions were defined as severe recurring disease activity (sRDA). Using a multivariate logistic model, we explored the influence of age, disease duration, sex, clinical, and MRI activity under FGL on the occurrence of RDA.

Results:

We identified 110 pwMS who discontinued FGL. Thirty-seven (33.6%) developed post-FGL RDA and 13 (11.8%) also fulfilled criteria for sRDA. Younger age at diagnosis [odds ratio (OR) = 1.10, p < 0.01], shorter disease duration (OR = 1.17, p < 0.01), and MRI activity under FGL (OR = 2.92, p = 0.046) were independent risk factors for the occurrence of post-FGL RDA.

Conclusion:

Individual risk assessment and optimal treatment sequencing can help to minimize the risk of post-FGL RDA. Early switch to highly effective disease-modifying therapy might reduce occurrence of post-FGL RDA.
Immunoadsorption as maintenance therapy for refractory neuromyelitis optica spectrum disorder
Authors: Heigl Franz , Hettich Reinhard , Fassbender Cordula , Klingel Reinhard , Mauch Erich , Durner Joachim , Kern Rolf , Kleiter Ingo
Published: February 2023

Background:

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing autoimmune disease of the central nervous system, affecting mainly optic nerves and spinal cord. NMOSD pathophysiology is associated with anti-aquaporin-4 (AQP4) immunoglobulin G (IgG) autoantibodies. Rapid extracorporeal elimination of autoantibodies with apheresis techniques, such as immunoadsorption (IA), was proven to be an effective treatment of NMOSD attacks. Data on the long-term use of IA to prevent attacks or progression of NMOSD are lacking.

Objectives:

The aim of this study was to evaluate efficacy and safety of maintenance IA for preventing recurrence of NMOSD attacks in patients refractory to other immunotherapies.

Design:

Case study.

Methods:

Retrospective analysis of two female patients with severe NMOSD refractory to conventional immunotherapies was performed. Both patients had responded to tryptophan IA (Tr-IA) as attack therapy and subsequently were treated with biweekly maintenance Tr-IA.

Results:

Patient 1 (AQP4-IgG seropositive, age 42 years) had 1.38 attacks of optic neuritis per year within 10.1 years before commencing regular Tr-IA. With maintenance Tr-IA for 3.1 years, one mild attack occurred, which was responsive to steroid pulse therapy. Expanded Disability Status Scale (EDSS) was stable at 5.0. Visual function score of the last eye improved from 3 to 1. Patient 2 (AQP4-IgG seronegative, age 43 years) experienced 1.7 attacks per year, mainly acute myelitis and optic neuritis, during the period of 10.0 years before the start of Tr-IA. During regular Tr-IA treatment, no further NMOSD attack occurred. The patient was clinically stable without any additional immunosuppressive treatment for 5.3 years. EDSS improved from 6.0 to 5.0, and the ambulation score from 7 to 1. Tolerability of Tr-IA was good in both patients. No serious adverse events occurred during long-term clinical trajectories.

Conclusion:

Tr-IA was well tolerated as maintenance treatment and resulted in clinical stabilization of two patients with highly active NMOSD, who were refractory to standard drug therapy.
Multisequence magnetic resonance neurography of brachial and lumbosacral plexus in chronic inflammatory demyelinating polyneuropathy: correlations with electrophysiological parameters and clinical features
Authors: Su Xiaoyun , Kong Xiangquan , Kong Xiangchuang , Zhu Qing , Lu Zuneng , Zheng Chuansheng
Published: February 2023

Background:

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare and challenging demyelinating disorder. It is necessary to increase our understanding of potential connections between imaging, electromyography, and clinical characteristics.

Objective:

The aim of this study was to evaluate the relationships between multisequence magnetic resonance neurography (MRN) findings, electrophysiological parameters, and clinical characteristics in CIDP patients.

Design:

A cross-sectional study.

Methods:

Overall, 51 CIDP patients underwent MRN of the brachial and lumbosacral plexus, and nerve conduction studies. The inflammatory Rasch-built overall disability scale (I-RODS) questionnaire, CIDP disease activity status (CADS) scale, and muscle strength scores were evaluated by two neurologists. Electrophysiological parameters, clinical information, and multiparameter-MRN were analyzed for correlations. Multiparameter-MRN includes diameter, nerve-to-muscle T2 signal intensity ratio (nT2), contrast-enhanced ratio (CR), fractional anisotropy (FA), and apparent diffusion coefficient (ADC) of bilateral plexus nerve roots.

Results:

Electrophysiological parameters that were not elicited were significantly higher in the lower extremities than in the upper extremities, and those were higher in sensory nerve conduction than in motor. There were moderate correlations between motor nerve conduction velocity and distal motor latency in nerve diameter, nT2, FA, and ADC, respectively (| r|, 0.45–0.64, p < 0.05). The correlations between CR and sensory nerve conduction velocity and peak latency were moderate, and ADC had a positive correlation with compound motor action potential amplitude (| r|, 0.45–0.63). FA correlated negatively with the course ( r = −0.62) and cerebrospinal fluid (CSF) protein ( r = −0.41), whereas ADC had correlated positively with CSF protein ( r = 0.34). Only CR had a moderately negative correlation with CADS ( r’s = −0.57). Muscle strength in all extremities was positively correlated with FA ( r’s range, 0.41–0.49). There was no significant correlation between I-RODS scores and multiparameter-MR.

Conclusion:

MRN-derived multiparameter [nerve size, nT2, and diffusion tensor imaging (DTI) parameters] could serve as quantitative biomarkers of myelin sheath integrity in CIDP. DTI parameters and CR correlated with clinical characteristics better than morphological parameters-MR for CIDP patients.
Health-related Quality of life of medical students during the COVID-19 pandemic: A cross-sectional study in Lebanon
Authors: Awada Sanaa , Ahmad Lama , Assi Roula Bou , Rafei Zad , Omar Chaza Abou , Hatem Georges
Published: February 2023

Objectives: This study aims to assess (i) the health-related Quality of Life (QoL) of medical students in Lebanon, (ii) its association with their general characteristics, and (iii) to investigate the combined effects of the predictors affecting the quality of life of students. Methods: An observational cross-sectional study was performed over three months, targeting 401 medical students from six universities. The 36-item Short Form survey was used to quantify the different QoL scores. Results: The physical component (PC) domains had higher scores than the mental component (MC) ones (70.2 vs. 55.9). Students aged 30 years or less had higher scores in all the PC domains than older students (70.9 vs. 59.3; p<0.010) but comparable scores in the MC domains (55.6 vs. 59.8; p>0.050). Single students had a significantly higher role-emotional score (63.5 vs. 49.0; p<0.050), and those studying in public universities had greater general health scores (57.7 vs. 53.7; p<0.050). Younger age significantly increased most of the health-related PC scores, and having chronic diseases decreased all the QoL scores except the mental health score. Conclusion: The QoL of medical students was negatively affected during the pandemic, particularly their mental health. Informed educational and health decisions are required to minimize this impact on their academic performance.
Polymer blends of poly(lactic acid) and starch for the production of films applied in food packaging: A brief review
Authors: Carneiro da Silva Lucas Rafael , Rios Alessandro de Oliveira , Campomanes Santana Ruth Marlene
Published: February 2023

The limited degradation of synthetic polymers used in food packaging when discarded in the environment is a major concern for society. Therefore, industry and academia have sought to develop biodegradable and eco-friendly materials for single-use in packaging. An interesting alternative for the food industry is biodegradable polymeric films, which is why different biopolymers have been used in the production of sustainable packaging. It is worth mentioning that the use of biodegradable polymers is one of the most successful innovations in the industry to address issues related to the environment. Among the available raw materials, starch extracted from different renewable sources is very promising for this purpose, due to its abundance, low-cost compared to other polymers and ability to produce non-toxic films. However, when used alone, pure starch has many limitations, which can be overcome by developing a mixture with other polymers (polymer blends), preferably from renewable and biodegradable sources, such as poly(lactic acid) (PLA). In this context, the absence of literature reviews evidencing the results of the application of films in foods led us to write this article, given the importance of polymer blends produced with different types of starch (cassava, corn, pea, potato, rice and wheat) and the PLA matrix. According to the results, it is clear that polymer blends based on PLA/Starch for food packaging are very promising, already being part of the industries solutions, aiming to minimize the large volume of plastic waste of petrochemical origin discarded in nature. Obviously, as with any technology, more research is needed to further improve the performance of the films, and while much research has made great strides, there are still limitations that prevent the commercialization of these materials.
Blended matters: Nurturing critical thinking
Authors: Jaswal Pooja , Behera Biswajit
Published: February 2023

The Organization for Economic Cooperation and Development (OECD) Learning Framework-2030 presents critical thinking as one of the transformative competencies for incorporation into the curriculum. Critical thinking refers to one’s ability to distinguish relevant information from irrelevant information, relate ideas, infer and justify whether a particular assumption is acceptable or unacceptable. This article argues that blended learning provides a concrete and meaningful context for enhancing learners’ critical thinking. Through collaboration, blended learning makes it possible to control, observe interactions, regulate tasks, and mediate in the acquisition of new knowledge. This form of collaboration creates a student-centered learning environment. Such a shift prompts to examine three objectives: (1) comprehend the creation of a blended learning environment. (2) discuss the characteristics of collaborative blended learning. (3) examine the role of collaboration in developing critical thinking among learners. To achieve the purpose of implementing a blended learning strategy in the classroom, the classroom teacher must create collaborative and participative learning experiences. Blended learning brings collaborative experience to develop higher-order thinking skills such as critical thinking.
Radiotherapy services in low resource settings: The situation in Nigeria
Authors: Akinwande Abidoye Matthew , Ugwuanyi Daniel Chimuanya , Chiegwu Hyacienth Uche , Idigo Felicitas , Ogolodom Michael Promise , Anakwenze Chidinma Pamela , Abi Roland , Odukoya Oluwaponmile
Published: February 2023

Objective:

About 50%–60% of all cancer cases will require radiotherapy during their treatment. Nonetheless, radiotherapy facilities are limited in low- and middle-income countries and despite high cancer burden in these regions of the world, only 5% have access to radiation therapy. This study identified the location of radiotherapy centers, the types of radiotherapy machines available and the personnel available in each radiotherapy center in Nigeria.

Methods:

A cross-sectional questionnaire-based study conducted across the six geopolitical zones of Nigeria from May 2020 to April 2021. A questionnaire having sections on facility profile, status of facility, and human resources, was used to elucidate information for the study. Descriptive statistics (frequency and proportion) were used to describe facilities’ characteristics, status, and human resources available.

Results:

Out of nine radiotherapy centers evaluated, the majority 33.3% ( n = 3) were found in the southwest geopolitical zone of Nigeria. Out of 10 equipment and accessories evaluated for availability, Ahmadu Bello University Teaching Hospital and University of Benin Teaching Hospital had the highest number of available equipment and accessories 90% ( n = 9) each respectively. Out of the nine centers evaluated, only four centers had at least one functional equipment. The highest number 64.3% ( n = 9) out of the 14 required number of staff in each center was found at University College Hospital. Out of 31 medical physicists identified, the majority 22.6% ( n = 7) was found at University of Nigeria Teaching Hospital.

Conclusion:

A high percentage of radiotherapy centers in Nigeria lacks the equipment and manpower to function optimally and is located within the southwest geopolitical zone of Nigeria. Therefore, proper investment in the radiotherapy service through private–public partnership, staff training, and equipment upgrade and maintenance could substantially improve the state of cancer care.
Spontaneous cesarean scar dehiscence during pregnancy: A case report and review of the literature
Authors: Tilahun Temesgen , Nura Abdulaziz , Oljira Rut , Abera Mesfin , Mustafa Jafar
Published: February 2023

Worldwide, the incidence of cesarean sections has increased. Cesarean scar dehiscence, in which the scar tissue from the prior cesarean section is disrupted and separated, is one of the most significant complications of cesarean deliveries. Spontaneous cesarean scar dehiscence is among rare obstetric events. It carries catastrophic fetal and maternal complications. Timing of occurrence, screening, diagnosis, and obstetrics management in the current and subsequent pregnancies are full of controversies. Here, we present a case of spontaneous cesarean scar dehiscence in a patient who had an inter-pregnancy interval of only 4 months. We present the case of spontaneous cesarean scar dehiscence during pregnancy in a 30-year-old patient from western Ethiopia. She got pregnant after 4 months of previous cesarean delivery. Currently, she presented to the hospital with previous two cesarean scars and a term pregnancy. Intraoperative findings showed separation of the uterine wall which is covered by only fetal membranes. After delivering the fetus and placenta, the uterus was repaired in two layers. The patient had a smooth postoperative course and was discharged on the fifth day with appropriate counseling. During pregnancy, there is a chance of spontaneous cesarean scar dehiscence. Therefore, it is essential to properly assess pregnant mothers who have had a previous cesarean scar. If the cesarean scar dehiscence is diagnosed before the elective cesarean section, the obstetrician should get prepared to prevent potential complications.
Candidate sites and other reference sections for the Global boundary Stratotype Section and Point of the Anthropocene series
Authors: Waters Colin N , Turner Simon D , Zalasiewicz Jan , Head Martin J
Published: February 2023

We review and compare proposals for 12 reference sections submitted to the Anthropocene Working Group of the International Subcommission on Quaternary Stratigraphy, of which one will be recommended as the Global boundary Stratotype Section and Point (GSSP) to define the base of the Anthropocene as a series within the Geological Time Scale. The sites span five continents and are located in diverse environments, with all but one sampled by coring. Many sites show annually resolved laminae (here considered optimal for GSSP selection) that can be independently dated radiometrically to confirm a complete succession over the critical interval. An extensive range of proxies, documenting profound human modification of the Earth System at around the mid-20th century interval, has been analysed. Airborne signals (e.g. radioisotopes, fly ash, stable carbon and nitrogen isotopes) provide the most widespread and near-isochronous proxies, applicable across most environments. Additional means of correlation include the appearance of microplastics and persistent organic pollutants, and shifts in heavy metal concentrations and lead isotope ratios. Assemblage changes of microfossils (and some macrofossils) in marine, estuarine and lake settings reflect environmental changes and biological introductions. These systematic and comprehensive datasets, with correlation established between sections, provide the basis for a proposal to formalize the Anthropocene.