bluuebunny/crossref_metadata_2025 huggingface dataset:
Training program for researchers in design and manufacturing of experimental prototypes for fluids engineering using additive technologies
Authors: Santamaría L , García M , Gharib A , Galdo M , Blanco E , Fernández J M , Velarde S
Published: October 2021

Experimental testing is one of the pillars in Fluids Engineering research. The arrival of rapid prototyping, and especially, Additive Manufacturing (AM), has revolutionized this field, allowing fast and flexible prototype manufacturing. Among these technologies, Fused Deposition Modelling (FDM) allows to fabricate complex parts using light, resistant, composite materials at a very affordable cost. To harness the full potential of this technology, the fluid dynamics engineering research group (GIFD) of the University of Oviedo started a training program for researchers in this area. This rich and complete program is presented herein, emphasizing its elaborate methodology and highlighting the successful case-studies derived from its application. Knowledge and integration of this technology has granted the capability of self-manufacturing customizable, low-cost experimental prototypes with adequate mechanical properties and accuracy, which produce high-quality results. Additionally, it has widened remarkably the possibilities of experimental research, resulting in a significant increase of experimental publications.
Re-design of a component of a lower-limb robotic exoskeleton for integrating sensing capacity and enhancing multi-material direct additive manufacturing
Authors: Minguella J , Challa P R , De Los Santos M A , Lobo J , Morey P , Font J M
Published: October 2021

The quest for the materialisation of advanced products is expanding the need for intelligent components and devices. One of the fields of application for such products is the medical technology industry, in which many value-added products could benefit from extending its embedded functionalities. To this regard, the obtention of such products via Additive Manufacturing Technologies would be very beneficial, providing that the design requirements could be met in a seamless and direct manner. In this context, the present article develops and analyses three design iterations of a component of a lower-limb robotic exoskeleton for integrating sensing capacity on it via multi-material direct additive manufacturing. In subsequent steps, the component geometry is optimised for additive direct manufacturing, and different functionalities are incorporated (padding for comfort and circuitry for sensing). For each iteration, the design is validated by means of finite element analysis and the main manufacturing parameters are assessed to compare the different times and costs yield. The third redesign incorporates three different materials (ABS, TPU and PE+Cu), but still it is possible to be 3D printed with a two extruder-head FDM 3D printer. The design and manufacturing results obtained could be implemented in further biomedical products or other parts requiring advanced functionalities.
Product development methodology: non-quality caused in production by mistakes in product development, its measurement and improvement integration in the product development process
Authors: Gracia C , Acero R , Yagüe J A
Published: October 2021

A new quality focused product development (NPD) methodology, applying lean manufacturing principles and Industry 4.0 paradigms is described in this paper. This methodology has been tested in a tailor-made equipment manufacturer for the retail sector, where tight product development times are needed. This requires a high agility in the processes, meaning the overlap of phases, the integration of processes, cooperation, and automation of tasks. We have generated a system concept that collects all the manufacturing incidences related to NPD, integrated in workshops stations, creating a system that enables real time data capture and a valuable feedback loop to NPD processes. Its implementation showed an improvement over 10% in the quality of the NPD process in a period of 3 months, an increase of the productivity in both product development and manufacturing areas, and a boost of the internal customer satisfaction in manufacturing area with the product development area.
Production optimization oriented to value-added: from conceptual to a simulation case study
Authors: Pérez S , Gallego S , García M
Published: October 2021

Management in companies today faces a true paradigm shift, characterized by a growing optimization of global value-added structures. To pursue this goal, lean philosophy is used as it allows applying sustainable improvements to the processes of a company, focusing on the value of the process and eliminating if possible or minimizing all those activities or tasks that when executed are not beneficial, that is, they do not add value. The research pursues to design and apply a systematic methodology to improve efficiency of a manufacturing plant increasing the value-added towards the end-customer. The objective of the work is to carry out an analysis of the manufacturing process of charged detonators to be potentially applied for other sectors. With the development of this work, it is described how it is possible to analyze, assess and implement improvement tools in manufacturing systems with a long tradition and that to date have not needed to improve their processes significantly due to market dynamics such as manufacturing of detonators. Moreover, a work methodology for optimizing manufacturing plants based on the proposed tools can be applied to other sectors.
Fatigue behaviour analysis of AISI 316-L parts obtained by machining process and additive manufacturing
Authors: Bermudo C , Trujillo F J , Martín S , Herrera M , Sevilla L
Published: October 2021

Due to the great technological growth, 3D printing is becoming of great relevance within the automotive, aerospace and even medicine sectors. With this manufacturing method, parts with a complex geometry can be manufacture with considerable time and material savings compared to traditional processes such as machining. However, additive manufacturing processes still have a series of unresolved problems. Present work makes a comparison between AISI 316-L samples obtained by Selective Laser Melting technique and Dry Machining. The comparison is focus in properties mainly relevant in the industrial sectors highlighted. Macro and microgeometrical deviations, such as roughness, roundness and straightness are obtained in each case study and compared. Results show that, although for the printed samples the material deposition direction plays a fundamental role, being the horizontal samples the ones with better results due to the direction of the layers, the machining process is the one with significant better results compared to the 3D printing process. After the macro and microgeometrical deviations measurements, all samples were subjected to a rotational bending fatigue test for a mechanical behaviour study. As expected, the mechanized specimens have a better fatigue behaviour due to the better surface finish, among other aspects. Between the additive manufactured specimens, the vertical is the one that presents a better behaviour due to the transverse orientation of the deposited layers.
Analysis of residual plastic deformation of blanked sheets out of automotive aluminium alloys through hardness map
Authors: Maculotti G , Bonù S , Bonù L , Cagliero R , Genta G , Marchiandi G , Galetto M
Published: October 2021

Reducing overall vehicle weight is essential to reduce fuel consumption and pollutant emission and to improve noise, vibration, and harshness (NVH) performances. The substitution with lighter alloys can involve the grand majority of vehicle components, depending on the market sector. In several applications, e.g., chassis, pulleys, and viscodampers, metal sheets are formed in several steps, each of whom work-hardens the material reducing the available residual plasticity. Typically, the process is designed via FEM, whose results are affected by the initial conditions, often neglected, and is performed on pre-processed materials from suppliers. In this regard, correctly simulating the first step of the process is critical. However, the related initial conditions, in terms of residual stress and strain induced by former preliminary operations, are often neglected. This work proposes a quick and economical experimental procedure based on a hardness map to estimate initial conditions and to validate FEM results. The procedure allows evaluating the material’s residual plasticity, which is necessary to process engineers to design following manufacturing steps. The approach is demonstrated on an industrially relevant case study, i.e., the blanking of an AA 5754, in use for water pump pulleys.
Labour productivity in mixed-model manual assembly 4.0
Authors: Miqueo A , Martín M , Torralba M , Yagüe J A
Published: October 2021

Manual assembly lines productivity is threatened by the increased complexity brought by mass customisation demand trends. Industry 4.0 offers potential solutions to address this situation, but the methodology to implement it is still a subject of study. As a preliminary step, this article aims to identify the dominant factors affecting the Key Performance Indicators of mixed-model assembly lines. To do so, parametric and discrete-events simulation models were developed, and Design of Experiments techniques were used. The results show that the key drivers for assembly line performance are number of work stations and batch size, and that increasing the work content ratio of the products assembled does not interact negatively with other factors. The results presented here pave the way for developing Industry 4.0 projects that address specifically the most relevant factors that affect assembly lines performance.
An approach for the identification of production process variables in cross-process chain production processes like battery cell production
Authors: Aichele A , Schäffer K , Sauer A
Published: October 2021

Europe is currently not competitive in battery cell production. In order to increase competitiveness, battery cell production must be made more efficient. A major factor in improving efficiency is the reduction of waste. This requires understanding the many dependencies between the production process variables within battery cell manufacturing. For clarifying these dependencies, knowledge of the variables is essential. The challenge here is to completely determine them. For this purpose, different tools and methods are applied. But, in the case of cross-process chain production processes like battery cell production, they quickly reach their limits because these tools are not suitable for the structure and properties of the respective processes. The aim of the approach presented here is to support a complete identification of all process variables of battery cell production in the best possible way.
Project portfolio risk assessment in digital transformation: challenges and opportunities
Authors: Mican C , Fernandes G , Araújo M , Ares E
Published: October 2021

Digital Transformation (DT) has its own challenges and demands on organizational strategy and processes. Consequently, DT also has implications on Project Portfolio Risk Assessment (PPRA). Thus, this study is focused on identifying these implications based on a structured search and content analysis of the literature in the field, which led to the identification of eight implications for risk assessment. Then, through qualitative analysis and according to the nature of each implication identified, a set of five challenges and three opportunities were established for PPRA considering DT context. This research shows that DT not only demands new considerations for PPRA but also offers opportunities to face them, leading to improve the PPRA impact on project portfolio management decision-making process. The present study contributes to the current PPRA research by outlining a view of how PPRA can be integrated into organizational DT. The challenges and opportunities identified could be used by practitioners and scholars to research, design, and implement PPRA in DT context.
Cyber Physical Systems implementation to develop a Smart Manufacturing
Authors: Morella P , Lambán M P , Royo J A , Sánchez J C , Muñoz O
Published: October 2021

This paper aims to show how the Cyber Physical Systems (CPS) are able to transform the actual manufacturing process. For that purpose, a case of study has been developed as an example of how to implement a CPS in a machine tool, specifically a 5-axis vertical milling machine of the Haas brand. This CPS transforms the acquisition of real-time data into worthy information for the industry. CPS implementation consists of 5 levels, which are explained and exemplified in this study. As a result of the implementation, it is shown a real-time indicator which takes part of our research. Our study concludes that CPS implementation enhance and speed up the decision-making of the companies.
First approach for the optimization and fabrication of a customizable esophageal stent prototype by 3D printing technologies
Authors: Ivorra J , Quiles L , Compañy L , Perez N J , Boronat T
Published: October 2021

The design of an esophageal stent is optimised using finite element analysis (FEM). The proposed design has been optimized in order to be manufactured by Fused Deposition Modelling (FDM) so that it can be easily customised to the patient. TPU is an elastomer that sometimes proposes some difficulties to be printed especially in relation to retraction, to avoid this kind of movements the stent has been specially designed to be printed in vase mode.
A case study of re-design for 3D printing: proposal to replace metallic fastening elements in an orthopedic corset with 3D printed PLA850 substitutes
Authors: Cerro A , Salinas F , Romero P E
Published: October 2021

Medicine is implementing revolutionary techniques like 3D printing in customized patient care. This enables tailor-made manufacturing with high productivity and low cost. In this work, the possibility of replacing the metal closures of an orthopedic corset using 3D printing has been studied. For the redesign, a multi-criteria decision analysis method is carried out. A design of experiments of nine specimens on the final prototype has been realized to determinate the most optimal printing parameters. The printing parameters analysed have been: infill density, infill pattern and printing speed. These specimens were subjected to a non-standardized bending test. From the experimental results, a triangular infill pattern, 100% infill density and 100 mm/s in printing speed provide the best bending strength values.
Safety efficiency value stream mapping (SEVSM) - A new tool to support the implementation of Lean Safety
Authors: Marques J P , Sá J C , Silva F J G , Pereira T , Ferreira L P , Santos G
Published: October 2021

Occupational health and safety constitutes a topic of great importance in organizations nowadays, given the social and financial implications that arise. In addition to these problems, the manufacturing industry is greatly responsible for the number of accidents at work worldwide. In parallel, organizations focus on improving processes and eradicating waste from production flows. Therefore, there is a need to develop tools which are able to combine these two factors. Metalworking industry suffers of safety problems usually due to the great weight of the parts involved, as well as the processes used. The Safety Efficiency Value Stream Mapping (SEVSM) tool was developed to address these issues with the purpose of facilitating the identification of the risk level at each workstation, which is determined through risk assessment, as well as by verifying the type of risk which causes the security breach, and then indicating the most appropriate Lean tool to be applied for risk resolution. Besides these, it is also possible to obtain a diagnosis of the production flow, enabling an analysis of the most significant production indicators. The results obtained pointed to a 38% reduction in the risk level associated to job preparation activities through the introduction of Total Productive Maintenance, as well as a 31.8% reduction in compressor assembly process time, and 49.3% in the risk level related to the latter through Standard Work.
Fused deposition modelling process environmental performance through the carbon footprint evaluation
Authors: Hernandez M E , Albajez J A , Lamban M P , Royo J , Santolaria J , Ng Corrales L C
Published: October 2021

Additive manufacturing (AM) is a free-form build process in which an object is created adding multiple layers. AM process is characterized by on-demand freeform part manufacturing with multiple materials and not for big production batches. There are different types of additive technologies that are capable of building pieces in diverse materials. For this study, various types of materials were tested in a fused deposition modeling (FDM) process using a standard workpiece and the build process was simulated in CURA software. The aim is to show the variability of the energy and the CO2 equivalent emissions produced in FDM manufacturing technology depending on the material used, specimen orientation, and the production batches. Variability in the material choice and the orientation of the piece was found for the environmental performance.
Evaluation of a soft skills serious game educational methodology in an industrial branches technical training program
Authors: Mateo J , Yagüe JA
Published: October 2021

The technical training of the industrial branches sometimes shows important shortcomings of new graduates in training and practice in analytical skills, high-level critical thinking, communication skills, teamwork and understanding of engineering in business practice. Gamification, understood as the application of design elements and game principles in the context of achieving learning outcomes, acquires a remarkable dimension and relevance. In this context, this job is focused on designing, developing, and measuring the results of a training module including gamification. This module is taught in an experimental training course aimed at a group with a heterogeneous educational level whose all its members play the role of team leader in manufacturing industries. The course is promoted by the Aragon (Spain) Government, and the Aragon Automotive Cluster Association, Caar. This work carries out a methodology and results evaluation project for soft skills problem solving and conflict resolution module, through gamification. For this evaluation, a discussion is carried out on the evaluation methods of gamified training. The work allows to obtain significant results on the methodology used in relation to the heterogeneity of the group. The study draws conclusions about the design of the methodology, the validity and efficacy of the educational method, the evaluation model and the relationship between training, experience and educational results.
The teaching-learning process in specific engineering subjects through different technology-based teaching methodologies applied during the State of Alarm
Authors: López O , Álvarez F J , González A , Rodríguez D , García J , Romero F
Published: October 2021

The safety measures contemplated in Real Decreto 463/2020, of March 14, which declares the State of Alarm for the management of the health crisis situation caused by COVID-19, determine the temporary suspension of the face-to-face educational activities and establish that these will have to be developed through distance and online modalities. This fact, which conditions traditional face-to-face teaching, forced us to look for new alternatives to meet the teaching objectives. This article presents the results and qualifications obtained by the students in the application of three different teaching methodologies in the teaching of the subject Manufacturing Processes II, of the University Center of Mérida in the Degree in Engineering in Industrial Design and Product Development (GIDIDP). The main objective has been to evaluate the influence of the different methodologies on the qualification of the students and the skills acquired. In the analysis of the results, in the application of the different methodologies, no significant differences have been obtained. The students assimilated the required competencies in a satisfactory way.
Integrating BIM in Industrial Engineering programs. A new strategy model
Authors: Meana V , García R , Bello A , León I , Giganto S
Published: October 2021

The implementation of the BIM in the AEC sector, both in companies and in academic institutions, is taking place mainly through the knowledge and handling of the software that makes its implementation possible. There are several public and private initiatives that provide professionals with workshops, courses, degree programs and even master’s programmes oriented towards knowledge of the BIM methodology. These are aimed at all types of professionals, from qualified technicians to unskilled labour. In order to achieve a truly successful implementation of BIM, it is important not to focus only on the technological perspective, but to base it on the human aspects involved in the methodology. Working the skills is as important, if not the most, as using the tools. It is the attitude of the professionals that will determine a successful integration. This paper brings together research works on the state of higher education in Spain in industrial engineering programmes related to BIM and the required competencies. Educational guides and also the needs of the sector are reviewed. New roles and skills demanded are also analysed. The implementation strategies and academic barriers found when integrating BIM methodology in higher education are studied in depth. Finally, the paper presents a model proposal that includes the main lines of work to integrate BIM so that the training of future graduates will be effective for the sector.
Impact of technological facilitators in the design and artisanal production processes. The Guarda Ninhos Project - craft and design of Gonçalo’s basketry
Authors: Lemos S , Alexandre C B , Ares E
Published: October 2021

This research project analyses the impact of the use of prototyping and digital manufacturing tools in the development of new products based on the theme of Gonçalo’s basketwork, in Guarda, Portugal [1]. Guarda Ninhos is an inclusive entrepreneurship project, the aim of which was to develop, produce and promote new local handicraft products. Solutions based on the socio-cultural, ecological and economic heritage of this region, knowledge immaterial heritage and expertise of their communities. Reinventing the culture of this place as a way of creating social and economic value, with the people who live there, was the followed line of action. Based on the results obtained, an attempt was made to outline forms of cooperation between this type of artisanal activities, with the most recent concepts of “industry 4.0” and industrial development methodologies - namely, (A) verifying the beneficial impact that the use of prototyping and digital fabrication tools can play in the design process of these products, optimising the development and production processes without jeopardising the premises that define the artisanal product; (B) contributing to the registration of ancestral knowledge and consolidation of artisanal processes and (C) showing how a strategic plan that aims to bring together and sustain the interdisciplinary artisan-designer relationship can be implemented.
The Gallbladder and Vermiform Appendix as Quality Assurance Indicators in Autopsy Pathology
Authors: Kaur Gagandeep , Williams Nathan , Vidhun Ramapriya , Stroever Stephanie , Dodge Jessica L
Published: October 2021

Objectives

We investigate the number of autopsy reports that did or did not document the presence or absence of the gallbladder or appendix or document abdominal scars in patients following cholecystectomy or appendectomy. We also report gallbladder and appendix pathology at autopsy.

Methods

Autopsy reports from patients 18 years or older autopsied at a community teaching hospital between January 1, 2009, and December 31, 2018 were reviewed. Nonabdominal autopsies were excluded. Histopathologic examination of the gallbladder and appendix was only performed if gross pathology was seen.

Results

Of the 385 autopsies studied, 48 (12.5%) had cholecystectomies, of which 6 (12.5%) did not document abdominal scars. Sixty-two (16.1%) had appendectomies, of which 12 (19.4%) did not document abdominal scars. The presence or absence of the gallbladder and appendix was not documented in 6 (1.6%) and 16 (4.2%) of reports, respectively. Pathology was seen in 87 (25.8%) gallbladders and 4 (1.2%) appendixes.

Conclusions

Absence of the gallbladder or appendix is a relatively common autopsy finding. Auditing autopsy reports for documentation of their presence or absence, along with associated abdominal scars, are potential quality assurance indicators of autopsy reports. Documentation of these elements could be improved by changing the autopsy template or using synoptic reporting.
Exploration of chemosensory ionotropic receptors in cephalopods: the IR25 gene is expressed in the olfactory organs, suckers, and fins of Sepia officinalis
Authors: Andouche Aude , Valera Stéphane , Baratte Sébastien
Published: October 2021

While they are mostly renowned for their visual capacities, cephalopods are also good at olfaction for prey, predator, and conspecific detection. The olfactory organs and olfactory cells are well described but olfactory receptors—genes and proteins—are still undescribed in cephalopods. We conducted a broad phylogenetic analysis of the ionotropic glutamate receptor family in mollusks (iGluR), especially to identify IR members (Ionotropic Receptors), a variant subfamily whose involvement in chemosensory functions has been shown in most studied protostomes. A total of 312 iGluRs sequences (including 111 IRs) from gastropods, bivalves, and cephalopods were identified and annotated. One orthologue of the gene coding for the chemosensory IR25 co-receptor has been found in Sepia officinalis (Soff-IR25). We searched for Soff-IR25 expression at the cellular level by in situ hybridization in whole embryos at late stages before hatching. Expression was observed in the olfactory organs, which strongly validates the chemosensory function of this receptor in cephalopods. Soff-IR25 was also detected in the developing suckers, which suggests that the unique « taste by touch » behavior that cephalopods execute with their arms and suckers share features with olfaction. Finally, Soff-IR25 positive cells were unexpectedly found in fins, the two posterior appendages of cephalopods, mostly involved in locomotory functions. This result opens new avenues of investigation to confirm fins as additional chemosensory organs in cephalopods.
Subterranean Survivorship and Seasonal Emergence ofLaricobiusspp. (Coleoptera: Derodontidae), Biological Control Agents for the Hemlock Woolly Adelgid
Authors: Foley Jeremiah R , McAvoy Thomas J , Grubb Christopher , Mayfield Albert E , Strahm Brian , Salom Scott M
Published: October 2021

Following the adventive arrival, subsequent spread, and ensuing impact of Adelges tsugae Annand (Hemiptera: Adelgidae), the hemlock woolly adelgid (HWA) in the eastern United States, a robust initiative was launched with the goal of decreasing ecosystem impacts from the loss of eastern hemlock (Pinales: Pinaceae). This initiative includes the use of biological control agents, including Laricobius spp. (Insecta: Coleoptera). Laboratory production of these agents is limited by subterranean mortality and early emergence. Therefore, the subterranean survivorship and timing of emergence of a mixture of Laricobius spp. was investigated. PVC traps internally lined with a sticky card and covered with a mesh screen were inserted into the soil to measure the percent emergence of adults based on the number of larvae placed within. The number of emerged adults in the field and laboratory-reared larval treatments was adjusted based on emergence numbers in the control and used as the response variable. Independent variables included in the final model were: treatment (field-collected vs. laboratory-reared), organic layer depth (cm), soil pH, and April-to-December mean soil moisture. No differences were found in survivorship between field-collected and laboratory-reared treatments. As pH and organic layer increased survivorship decreased, significantly. Although the majority of emergence occurred in the fall, emergence also occurred in spring and summer. The occurrence of spring and summer emergence and low survivorship (17.1 ± 0.4%) in the field across all treatments suggests that these are characteristics of Laricobius spp. field biology in their introduced range and not artifacts of the laboratory rearing process.
High Rainfall May Induce Fungal Attack of Hemlock Woolly Adelgid (Hemiptera: Adelgidae) Leading to Regional Decline
Authors: Chandler Jennifer L , Elkinton Joseph S , Orwig David A
Published: October 2021

Hemlock woolly adelgid (HWA; Adelges tsugae Annand (Hemiptera: Adelgidae)) is the cause of widespread mortality of Carolina and eastern hemlock (Tsuga caroliniana Engelmann and T. canadensis (L.) Carrière) throughout the eastern United States (U.S.). Since its arrival in the northeastern U.S., HWA has steadily invaded and established throughout eastern hemlock stands. However, in 2018, anecdotal evidence suggested a sharp, widespread HWA decline in the northeastern U.S. following above-average summer and autumn rainfall. To quantify this decline in HWA density and investigate its cause, we surveyed HWA density in hemlock stands from northern Massachusetts to southern Connecticut and analyzed HWA density and summer mortality in Pennsylvania. As native fungal entomopathogens are known to infect HWA in the northeastern U.S. and rainfall facilitates propagation and spread of fungi, we hypothesized high rainfall facilitates fungal infection of aestivating nymphs, leading to a decline in HWA density. We tested this hypothesis by applying a rain-simulation treatment to hemlock branches with existing HWA infestations in western MA. Our results indicate a regional-scale decline and subsequent rebound in HWA density that correlates with 2018 rainfall at each site. Experimental rain treatments resulted in higher proportions of aestivating nymphs with signs of mortality compared to controls. In conjunction with no evidence of increased mortality from extreme winter or summer temperatures, our results demonstrate an indirect relationship between high rainfall and regional HWA decline. This knowledge may lead to better prediction of HWA population dynamics.
Effect of Spatiotemporal Association and Trophic Interactions Between Aphidophagous Coccinellids Toward Aphid Control
Authors: Rocca Margarita , Díaz Lucas María Florencia , Greco Nancy Mabel
Published: October 2021

Predator diversity in a system can have different results on the biological control of pests. Positive results can arise if natural enemies have niche complementarity, whereas negative effects can occur when one enemy interferes with heterospecifics—e.g., via intraguild predation—resulting in weaker pest suppression. Nevertheless, a coexistence is possible if enemies use the resource differentially leading to resource partitioning, and/or if the intraguild prey has some competitive advantage over the intraguild predator—i.e., is better at exploiting the shared resource or exhibits avoidance behavior. In this study, we conducted a series of field-sampling and semifield experiments to elucidate the spatiotemporal association patterns of the coccinellids Eriopis connexa (Germar) and Cycloneda sanguinea L. (Coleoptera: Coccinellidae) and determine how the trophic interactions between them could affect the biological control of aphids. We found that both coccinellid species coexist in sweet-pepper crops over time, and this coexistence could be explained by a temporal niche complementarity. Despite cooccurring spatially, they were segregated at the leaf level, which segregation can be explained by an avoidance behavior to prevent negative trophic interactions, such as cannibalism and intraguild predation. Under semifield conditions, the possible negative trophic interactions did not affect the control of aphids when both species were present, but the density of C. sanguinea was reduced at the end of the experiment. These results suggest that biological control strategies that include both species would be positive for the control of aphids on the basis of these considerations.
Prognostic impact of different parameters of right ventricular systolic function in patients with significant tricuspid regurgitation. A cardiac magnetic resonance study
Authors: Hinojar Baydes R , Gonzalez-Gomez A , Garcia-Martin A , Monteagudo J M , Alonso-Salinas G , Hernandez-Jimenez S , Fernandez-Mendez M A , Garcia De Vicente A , Rajjoub Al-Mahdi E A , Pascual-Izco M , Zamorano J L , Fernandez-Golfin C
Published: October 2021

Background

Right ventricle (RV) dysfunction represent an established criteria for intervention in patients with significant tricuspid regurgitation (TR). RV ejection fraction (RVEF) by Cardiac Magnetic Resonance (CMR) is considered the gold standard of RV function; however it is influenced by changes of preload conditions and may remain unaffected until late stages in severe TR. Novel measures of RV function such as RV longitudinal shortening (RV-LS) and effective RV ejection fraction (eRVEF) may be earlier markers of RV dysfunction.

Purpose

To compare the prognostic impact of conventional and novel parameters of RV systolic function.

Methods

Consecutive patients in stable clinical condition evaluated in the Heart Valve Clinic with significant TR (severe, massive or torrential TR) undergoing a CMR study were included. In addition to conventional parameters of biventricular volume and function, RV-LS and eRVEF were assessed as novel parameters of RV function. RV-LS was assessed in the 4-chamber view by measuring the displacement of the tricuspid annulus during the cardiac cycle. The length between the epicardial border of the LV apex and the middle of a line connecting the origins of the tricuspid valve leaflets was measured in both end-systole and end-diastole. Effective RVEF (eRVEF) is a measure of RV global systolic function but corrected by TR volume. Both formulas are represented in figure 1. A combined endpoint of hospital admission due to right heart failure and cardiovascular mortality was defined

Results

75 patients were included in this study (age 75±8 years, 75% female, 91% functional TR) During a median follow-up of 3 years (IQR: 1.4–3.9 years), 39% of the patients (n=29) experienced the combined endpoint. RV-LS and eRVEF identified higher rates of RV dysfunction than RVEF. RV-LS of ≥−14% and eRVEF of ≤34% were associated with impaired prognosis (figure 2). After adjustment of age and LVEF, both eRVEF (adjusted HR per abnormal value: 5.29 95% CI, [2.25–12.4]) and RV-LS (adjusted HR per abnormal value: 3.46, 95% CI, [1.13–9.17]) were significantly associated with outcomes. Among all parameters of RV function, eRVEF was the strongest predictor of outcomes, incremental to RVEF (Δ C-statistic 0.139 [0.040–0.237], p=0.005).

Conclusion

RV function is crucial for determining optimal timing for TR intervention. RV-LS and eRVEF identify higher rates of RV dysfunction beyond RVEF. Among all measures of RV function, eRVEF held the strongest association with outcome, incremental to RVEF.

Funding Acknowledgement

Type of funding sources: None. Figure 1. RV-LS and eRVEF calculationFigure 2. Kaplan Meier Curves
Natural variation in the transcriptional response ofDrosophila melanogasterto oxidative stress
Authors: Ramnarine Timothy J S , Grath Sonja , Parsch John
Published: October 2021

Broadly distributed species must cope with diverse and changing environmental conditions, including various forms of stress. Cosmopolitan populations of Drosophila melanogaster are more tolerant to oxidative stress than those from the species’ ancestral range in sub-Saharan Africa, and the degree of tolerance is associated with an insertion/deletion polymorphism in the 3′ untranslated region of the Metallothionein A (MtnA) gene that varies clinally in frequency. We examined oxidative stress tolerance and the transcriptional response to oxidative stress in cosmopolitan and sub-Saharan African populations of D. melanogaster, including paired samples with allelic differences at the MtnA locus. We found that the effect of the MtnA polymorphism on oxidative stress tolerance was dependent on the genomic background, with the deletion allele increasing tolerance only in a northern, temperate population. Genes that were differentially expressed under oxidative stress included MtnA and other metallothioneins, as well as those involved in glutathione metabolism and other genes known to be part of the oxidative stress response or the general stress response. A gene coexpression analysis revealed further genes and pathways that respond to oxidative stress including those involved in additional metabolic processes, autophagy, and apoptosis. There was a significant overlap among the genes induced by oxidative and cold stress, which suggests a shared response pathway to these two stresses. Interestingly, the MtnA deletion was associated with consistent changes in the expression of many genes across all genomic backgrounds, regardless of the expression level of the MtnA gene itself. We hypothesize that this is an indirect effect driven by the loss of microRNA binding sites within the MtnA 3′ untranslated region.
The relation of number of childbirths with age at natural menopause: a population study of 310 147 women in Norway
Authors: Gottschalk Marthe S , Eskild Anne , Hofvind Solveig , Bjelland Elisabeth K
Published: October 2021

STUDY QUESTION

Does age at natural menopause increase with increasing of number of childbirths?

SUMMARY ANSWER

Age at menopause increased with increasing number of childbirths up to three childbirths; however, we found no further increase in age at menopause beyond three childbirths.

WHAT IS KNOWN ALREADY

Pregnancies interrupt ovulation, and a high number of pregnancies have therefore been assumed to delay menopause. Previous studies have had insufficient statistical power to study women with a high number of childbirths. Thus, the shape of the association of number of childbirths with age at menopause remains unknown.

STUDY DESIGN, SIZE, DURATION

A retrospective population study of 310 147 women in Norway who were 50–69 years old at data collection.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The data were obtained by two self-administered questionnaires completed by women attending BreastScreen Norway, a population-based screening program for breast cancer. The associations of number of childbirths with age at menopause were estimated as hazard ratios by applying Cox proportional hazard models, adjusting for the woman’s year of birth, cigarette smoking, educational level, country of birth, oral contraceptive use and body mass index.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with three childbirths had the highest mean age at menopause (51.36 years; 95% CI: 51.33–51.40 years), and women with no childbirths had the lowest (50.55 years; 95% CI: 50.48–50.62 years). Thus, women with no childbirths had higher hazard ratio of reaching menopause compared to women with three childbirths (reference group) (adjusted hazard ratio, 1.24; 95% CI: 1.22–1.27). Beyond three childbirths, we estimated no further increase in age at menopause. These findings were confirmed in sub-analyses among (i) women who had never used hormonal intrauterine device and/or systemic menopausal hormonal therapy; (ii) women who were born before 1950 and (iii) women who were born in 1950 or after.

LIMITATIONS, REASONS FOR CAUTION

Information about age at menopause was based on self-reports.

WIDER IMPLICATIONS OF THE FINDINGS

If pregnancies truly delay menopause, one would expect that women with the highest number of childbirths had the highest age at menopause. Our results question the assumption that interrupted ovulation during pregnancy delays menopause.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the South-Eastern Norway Regional Health Authority [2016112 to M.S.G.] and by the Norwegian Cancer Society [6863294-2015 to E.K.B.]. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.
Completion lobectomy after anatomical segmentectomy
Authors: Takamori Satoshi , Oizumi Hiroyuki , Suzuki Jun , Suzuki Katsuyuki , Watanabe Hikaru , Sato Kaito
Published: October 2021

Patient selection flowchart.

OBJECTIVES

Completion lobectomy (CL) after anatomical segmentectomy in the same lobe can be complicated by severe adhesions around the hilar structures and may lead to fatal bleeding and lung injury. Therefore, we aimed to investigate the perioperative outcomes of CL after anatomical segmentectomy.

METHODS

Among 461 patients who underwent anatomical segmentectomy (thoracotomy, 62 patients; thoracoscopic surgery, 399 patients) between January 2005 and December 2019, data of patients who underwent CL after segmentectomy were extracted and analysed in this study.

RESULTS

Eight patients underwent CL after segmentectomy. CL was performed via video-assisted thoracic surgery in 3 patients and thoracotomy in 5 patients. In each case, there were moderate to severe adhesions. Four patients required simultaneous resection of the pulmonary parenchyma and pulmonary artery. Thoracotomy was not required after thoracoscopic surgery in any patient. Two patients experienced complications (air leakage and arrhythmia). The median duration of hospitalization after CL was 6 (range, 5–7) days. No postoperative mortality or recurrence of lung cancer was observed. All the patients with lung cancer were alive and recurrence-free at the time of publication.

CONCLUSIONS

Although individual adhesions render surgery difficult, CL after anatomical segmentectomy shows acceptable perioperative outcomes. However, CL by video-assisted thoracoscopic surgery may be considered on a case-by-case basis depending on the initial surgery.
Heat transfer and economic analyses of using various nanofluids in shell and tube heat exchangers for the cogeneration and solar-driven organic Rankine cycle systems
Authors: Mehrpooya Mehdi , Dehqani Meqdad , Mousavi Seyed Ali , Moosavian SM Ali
Published: October 2021

This project attempts to evaluate the effect of nanofluids on thermal performance and the economic parameters of shell and tube heat exchangers. First, two thermodynamic processes including combined heat and power (CHP) system and solar-driven organic Rankine cycle (ORC) are simulated using the Aspen HYSYS. The CHP and ORC systems can produce 25 MW and 175.8 kW of electrical power, respectively. Thereafter, to use the nanofluids in the heat exchangers of these systems, the thermophysical specifications are modeled in the MATLAB software and validated with previous investigations. For this purpose, four kinds of nanofluids consisting of Al2O3/H2O, TiO2/H2O, Cu/H2O and Ag/H2O are utilized. According to the results, by adding the nanoparticles to the base fluid, the thermal conductivity, viscosity, heat transfer coefficient and density increase and the heat capacity reduces. The economic assessment and parametric analysis on concentration of the nanoparticles are conducted. The variations of concentration of nanoparticles are taken to be 0.5–4%. It was found that in ORC system, by employing 1% concentration of Ag/H2O, Cu/H2O, Al2O3/H2O and TiO2/water nanofluids, the overall cost is reduced by 3.1%, 1.9%, 1.2% and 0.9%, respectively. Also, in CHP system, at a concentration of 2% for Ag/water, Cu/water Al2O3/water and TiO2/water nanofluids, the total cost decreases by 4.4%, 3%, 1% and 0.5%, respectively. It was denoted that the utilization of nanofluids in thermodynamic cycles can considerably reduce the total cost of heat exchangers and the whole process.
Bone changes with candidate PrEP regimens containing tenofovir disoproxil fumarate and/or maraviroc and/or emtricitabine in US men and women: HPTN 069/ACTG A5305
Authors: Brown Todd T. , Yuhas Krista , Mayer Kenneth H. , Landovitz Raphael J. , Marzinke Mark A. , Hendrix Craig W. , Chen Ying Q. , Klingman Karen L. , Chege Wairimu , Mccauley Marybeth B. , Gulick Roy M. , Wilkin Timothy J.
Published: October 2021

Background

Tenofovir disoproxil fumarate-containing pre-exposure prophylaxis (PrEP) has been associated with decreases in bone mineral density (BMD), but the bone effects of other non-tenofovir disoproxil fumarate candidate PrEP regimens are not well described.

Methods

The HPTN 069/ACTG A5305 study randomized 406 US cisgender men and transgender women, and 188 cisgender women at risk for HIV infection to one of four double-blinded regimens: (i) maraviroc; (ii) maraviroc + emtricitabine; (iii) maraviroc + tenofovir disoproxil fumarate; or (iv) tenofovir disoproxil fumarate + emtricitabine. BMD was measured in a subset of participants at the lumbar spine (LS) and hip by dual-energy X-ray absorptiometry (DXA) at baseline and 48 weeks. Percentage change in LS and hip BMD was compared between the tenofovir disoproxil fumarate- and non-tenofovir disoproxil fumarate-containing arms by Wilcoxon rank-sum tests and multiple linear regression adjusting for sex, race and baseline BMI.

Results

At baseline (n = 307), the median age was 33 years, 56% male and 43% black. At the hip, the median percentage change in BMD at 48 weeks was –1.05% in the tenofovir disoproxil fumarate arms and 0.0% in the non-tenofovir disoproxil fumarate arms (between group P = 0.001). No interaction by sex was observed. The median percentage change in LS BMD was not different between arms.

Conclusions

Tenofovir disoproxil fumarate-containing PrEP was associated with significantly greater bone loss compared with maraviroc ± emtricitabine PrEP at the hip, but not the LS. The BMD changes at the hip were similar in magnitude in men and women.
Ultra-deep long-read sequencing detects IS-mediated gene duplications as a potential trigger to generate arrays of resistance genes and a mechanism to induce novel gene variants such as blaCTX-M-243
Authors: Schuster Christopher F. , Weber Robert E. , Weig Michael , Werner Guido , Pfeifer Yvonne
Published: October 2021

Background

Extended-spectrum β-lactamases (ESBLs) are enzymes that can render their hosts resistant to various β-lactam antibiotics. CTX-M-type enzymes are the most prevalent ESBLs and the main cause of resistance to third-generation cephalosporins in Enterobacteriaceae. The number of described CTX-M types is continuously rising, currently comprising over 240 variants. During routine screening we identified a novel blaCTX-M gene.

Objectives

To characterize a novel blaCTX-M variant harboured by a multidrug-resistant Escherichia coli isolate of sequence type ST354.

Methods

Antibiotic susceptibilities were determined using broth microdilution. Genome and plasmid sequences were reconstructed using short- and long-read sequencing. The novel blaCTX-M locus was analysed using long-read and Sanger sequencing. Plasmid polymorphisms were determined in silico on a single plasmid molecule level.

Results

The novel blaCTX-M-243 allele was discovered alongside a nearly identical blaCTX-M-104-containing gene array on a 219 kbp IncHI2A plasmid. CTX-M-243 differed from CTX-M-104 by only one amino acid substitution (N109S). Ultra-deep (2300-fold coverage) long-read sequencing revealed dynamic scaling of the blaCTX-M genetic contexts from one to five copies. Further antibiotic resistance genes such as blaTEM-1 also exhibited sequence heterogeneity but were stable in copy number.

Conclusions

We identified the novel ESBL gene blaCTX-M-243 and illustrate a dynamic system of varying blaCTX-M copy numbers. Our results highlight the constant emergence of new CTX-M family enzymes and demonstrate a potential evolutionary platform to generate novel ESBL variants and possibly other antibiotic resistance genes.