bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluid escapes to the “third space” during anesthesia, a commentary
Authors: Hahn Robert G.
Published: November 2020

Background

The “third fluid space” is a concept that has caused much confusion for more than half a century, dividing anesthesiologists into believers and non‐believers.

Aim

To challenge the existence of the “third fluid space” based on analysis of crystalloid fluid kinetics.

Methods

Data on hemodilution patterns from 157 infusion experiments performed in volunteers and from 85 patients undergoing surgery under general anesthesia were studied by population volume kinetic analysis. Elimination of infused crystalloid fluid from the kinetic model could occur either as urine or "third space" accumulation. The latter fluid volume remained in the body, but without equilibrating with the plasma within the 3‐4 h of the experiment.

Results

The rate constant for "third space" loss of fluid accounted for 20% of the elimination in conscious volunteers and for 75% during general anesthesia and surgery. The two elimination constants showed a reciprocal relationship, resulting in that "third‐space" losses increase when urinary excretion is restricted. The effect on the plasma volume was smaller than indicated by these figures because fluid distributed to the extravascular space continuously redistributed to the plasma. Worked‐out examples show that one‐third of an infused crystalloid volume has been confined to the "third space" after 3 h of surgery. When equilibration with the plasma eventually occurs, which is necessary for excretion of the fluid, is not known.

Conclusion

During anesthesia and surgery one third of the infused crystalloid fluid is at least temporarily unavailable for excretion, which probably contributes to postoperative weight increase and edema.
Patient‐reported oral hygiene and implant outcomes in general dental practice
Authors: Cheung Monique Charlene , Hopcraft Matthew S. , Darby Ivan B.
Published: November 2020

Background

This study investigated the possible correlations between patient‐performed implant hygiene and peri‐implant success and disease, as well as patient‐reported outcomes, in a community‐based cohort.

Methods

Fifty‐one patients (78 implants) from two private general practices were surveyed on their dental implant treatment history, oral hygiene instructions (OHI) received, home hygiene habits and current implant concerns. Their dentition, plaque/calculus scores and clinical implant parameters were examined. Correlations between hygiene habits, risk factors, implant success and peri‐implant disease rates were assessed.

Results

Implants had a patient‐reported mean time in function of 6.7 years. Floss (74.4%), interdental brushes (IDB) (44.9%) and mouthwash (39.7%) were commonly used, while 7.7% of implants were only cleaned by brushing. Over half (56.4%) of implants fulfilled the success criteria, 61.5% had peri‐implant health, 24.4% had mucositis and 7.7% had peri‐implantitis. Only brushing (P < 0.001) and detectable plaque/calculus (P < 0.001) were significantly associated with more peri‐implant disease. Local prosthetic factors affecting cleaning accessibility significantly reduced implant success (P < 0.001). Patients reported mixed recall of implant OHI, 7.7% of implants were aesthetically unsatisfactory and 9.0% had peri‐implant symptoms.

Conclusions

Lack of interproximal cleaning and the presence of plaque/calculus were significantly associated with peri‐implant disease in a community‐based general practice setting, and patients reported mixed recall of OHI.
Exploring the limits of prolonged apnoea with high‐flow nasal oxygen: an observational study
Authors: Piosik Z. M. , Dirks J. , Rasmussen L. S. , Kristensen C. M. , Kristensen M. S.
Published: November 2020

High‐flow nasal oxygen is increasingly used for oxygenation during apnoea. Extending apnoea duration using this technique has mainly been investigated during minor laryngeal surgery, but it is unclear how long it can be administered for before it should be discontinued due to acidosis. We aimed to describe the dynamics of arterial blood gases during apnoeic oxygenation with high‐flow nasal oxygen with jaw thrust only, to explore the limits of this technique. We included adult orthopaedic patients scheduled for general anaesthesia. After pre‐oxygenation, anaesthesia with neuromuscular blockade was induced and high‐flow nasal oxygen (70 l.min−1) was continued with jaw thrust as the only means of airway management, with monitoring of vital signs and arterial blood gas sampling every 5 minutes. Apnoeic oxygenation with high‐flow nasal oxygen was discontinued when arterial carbon dioxide tension (PaCO2) exceeded 12 kPa or pH fell to 7.15. This technique was used in 35 patients and median (IQR [range]) apnoea time was 25 (20–30 [20–45]) min and was discontinued in all patients when pH fell to 7.15. The mean (SD) PaCO2 increase was 0.25 (0.06) kPa.min−1 but it varied substantially (range 0.13–0.35 kPa.min−1). Mean (SD) arterial oxygen tension was 48.6 (11.8) kPa when high‐flow nasal oxygen was stopped. Patients with apnoea time > 25 minutes were significantly older (p = 0.025). We conclude that apnoeic oxygenation with high‐flow nasal oxygen resulted in a significant respiratory acidosis that varies substantially on the individual level, but oxygenation was maintained.
Camostat mesylate against SARS‐CoV‐2 and COVID‐19—Rationale, dosing and safety
Authors: Breining Peter , Frølund Anne Lier , Højen Jesper Falkesgaard , Gunst Jesper Damsgaard , Staerke Nina B. , Saedder Eva , Cases‐Thomas Manuel , Little Paul , Nielsen Lars Peter , Søgaard Ole S. , Kjolby Mads
Published: November 2020

The coronavirus responsible for COVID‐19, SARS‐CoV‐2, utilizes a viral membrane spike protein for host cell entry. For the virus to engage in host membrane fusion, SARS‐CoV‐2 utilizes the human transmembrane surface protease, TMPRSS2, to cleave and activate the spike protein. Camostat mesylate, an orally available well‐known serine protease inhibitor, is a potent inhibitor of TMPRSS2 and has been hypothesized as a potential antiviral drug against COVID‐19. In vitro human cell and animal studies have shown that camostat mesylate inhibits virus‐cell membrane fusion and hence viral replication. In mice, camostat mesylate treatment during acute infection with influenza, also dependent on TMPRSS2, leads to a reduced viral load. The decreased viral load may be associated with an improved patient outcome. Because camostat mesylate is administered as an oral drug, it may be used in outpatients as well as inpatients at all disease stages of SARS‐CoV‐2 infection if it is shown to be an effective antiviral agent. Clinical trials are currently ongoing to test whether this well‐known drug could be repurposed and utilized to combat the current pandemic. In the following, we will review current knowledge on camostat mesylate mode of action, potential benefits as an antiviral agent and ongoing clinical trials.
The epidemiology of eczema in children and adults in England: A population‐based study using primary care data
Authors: de Lusignan Simon , Alexander Helen , Broderick Conor , Dennis John , McGovern Andrew , Feeney Claire , Flohr Carsten
Published: November 2020

Background

Whilst eczema is a common inflammatory skin condition, we lack contemporary estimates of disease incidence and prevalence across the lifespan.

Objective

To estimate the incidence and prevalence of eczema in children and adults in England and variation by sociodemographic factors (sex, socio‐economic status, ethnicity, and geography).

Methods

We used the Royal College of General Practitioners Research and Surveillance Centre primary care research database of 3.85 million children and adults registered with participating general practitioner practices between 2009 and 2018 inclusive. Eczema incidence was defined as the first‐ever diagnosis of eczema recorded in the primary care record, and eczema prevalence was defined as fulfilment of criteria for active eczema (two eczema records appearing in the primary care record within any one‐year period).

Results

Eczema incidence was highest in infants younger than 1 year (15.0 per 100 person‐years), lowest in adults aged 40–49 (0.35 p/100 person‐years), and increased from middle age to a second smaller peak in people 80 years or older (0.79 p/100 person‐years). Eczema prevalence was highest in children aged 2 (16.5%) and lowest in adults aged 30–39 (2.8%). Eczema incidence was higher in male infants (<2) and male adults older than 70; for all other ages, incidence was higher in females. Eczema was more common in Asian and black ethnic groups than in people of white ethnicity. Higher socio‐economic status was associated with a greater incidence of eczema in infants younger than 2, but the reverse was seen for all other age groups. Both incidence and prevalence of eczema were greater in urban settings and in North‐West England.

Conclusions and Clinical Relevance

Eczema has a bimodal distribution across the lifespan. We observed differences in incidence and prevalence of eczema by ethnicity, geography, sex, and socio‐economic status, which varied in magnitude throughout life.
The investigation of diabetes in people living with HIV: A systematic review
Authors: Daultrey Harriet , Youseff Elaney , Wright Juliet , Davies Kevin , Chakera Ali J. , Levett Tom
Published: November 2020

Aims

HbA1c is reported to underestimate glycaemia in people living with HIV (PLHIV). There is not an internationally agreed screening method for diabetes. The primary aim was to identify which tests are performed to diagnose and monitor diabetes in PLHIV. Secondary aims were to identify whether prevalence or incidence of diabetes differs according to marker of glycaemia and how figures compare in PLHIV compared to people without.

Methods

Electronic databases were searched for studies investigating diabetes in PLHIV, not pregnant, aged ≥18 years. Narrative analysis and descriptive statistics were used to describe which markers of glycaemia, and their frequency, were employed in the diagnosis and monitoring of diabetes in PLHIV. Diagnostic studies provided prevalence or incidence of diabetes.

Results

In all, 45 of 1028 studies were included. Oral glucose tolerance test (OGTT), fasting glucose (FG), HbA1c and Fructosamine were used to investigate diabetes. In total, 27 studies described diagnosing diabetes, 14 using OGTT, 12 FG and 7 HbA1c. All 18 studies monitoring diabetes used HbA1c. Prevalence ranged from 1.3% to 26% and incidence 2.9% to 12.8%. Studies using glucose and HbA1c reported HbA1c to diagnose fewer people with diabetes, monitoring studies found HbA1c to underestimate glycaemia levels. Controlled studies demonstrate diabetes was more common in PLHIV.

Conclusion

OGTT was used most frequently to diagnose diabetes, and HbA1c to monitor known diabetes. Prevalence and incidence varied depending on marker of glycaemia used. Studies reported a discrepancy in accuracy of HbA1c in PLHIV, to address this, well‐designed, prospective studies, providing individual‐level data on HbA1c levels and an additional marker of glycaemia in PLHIV are needed.
Global status of knowledge for prevention and emergency management of traumatic dental injuries in dental professionals: Systematic review and meta‐analysis
Authors: Tewari Nitesh , Sultan Farheen , Mathur Vijay Prakash , Rahul Morankar , Goel Shubhi , Bansal Kalpana , Chawla Amrita , Haldar Partha , Pandey Ravindra Mohan
Published: November 2020

Background

Dental professionals are the primary care providers for traumatic dental injuries (TDI). The dental traumatology literature has a number of studies evaluating the knowledge of dental professionals from different parts of the world but its global status is unknown. Hence, the aim of this systematic review was to assess the global status of knowledge for the prevention and emergency management of TDI in dental professionals and to provide recommendations for future research.

Materials and Methods

The protocol was designed as per the PRISMA guidelines and registered in PROSPERO (CRD42020192381). A broad‐based search using text words and MeSH terms was performed in established databases as per a pre‐defined strategy without any distinction of language and year of publication. Studies without details of the questionnaire, knowledge score, validity and reliability were excluded. Data extraction was performed, risk of bias assessment was done using the Joanna Briggs Institute's critical appraisal tool, and a meta‐analysis was performed.

Results

Sixteen studies, which had been published between 2008 and 2020, were included for qualitative synthesis. Most of them were cross‐sectional, used convenience sampling and evaluated knowledge for avulsion. Previous dental trauma training was undertaken by <50% of the participants of five studies, <50% knew about the correct approach in management of complicated crown fractures in three studies and ≤60% in four studies knew the critical time for replantation. There was insufficient level of knowledge in >50% of the included studies. High risk of bias was found in three studies.

Conclusion

The knowledge level in several areas of the world was unknown. The studies lacked uniformity in methods and well‐designed questionnaires and they revealed insufficient levels of knowledge among dental professionals.
RivFishTIME: A global database of fish time‐series to study global change ecology in riverine systems
Authors: Comte Lise , Carvajal‐Quintero Juan , Tedesco Pablo A. , Giam Xingli , Brose Ulrich , Erős Tibor , Filipe Ana F. , Fortin Marie‐Josée , Irving Katie , Jacquet Claire , Larsen Stefano , Sharma Sapna , Ruhi Albert , Becker Fernando G. , Casatti Lilian , Castaldelli Giuseppe , Dala‐Corte Renato B. , Davenport Stephen R. , Franssen Nathan R. , García‐Berthou Emili , Gavioli Anna , Gido Keith B. , Jimenez‐Segura Luz , Leitão Rafael P. , McLarney Bill , Meador Jason , Milardi Marco , Moffatt David B. , Occhi Thiago V. T. , Pompeu Paulo S. , Propst David L. , Pyron Mark , Salvador Gilberto N. , Stefferud Jerome A. , Sutela Tapio , Taylor Christopher , Terui Akira , Urabe Hirokazu , Vehanen Teppo , Vitule Jean R. S. , Zeni Jaquelini O. , Olden Julian D.
Published: November 2020

Motivation

We compiled a global database of long‐term riverine fish surveys from 46 regional and national monitoring programmes and from individual academic research efforts, with which numerous basic and applied questions in ecology and global change research can be explored. Such spatially and temporally extensive datasets have been lacking for freshwater systems in comparison to terrestrial ones.

Main types of variables contained

The database includes 11,386 time‐series of riverine fish community catch data, including 646,270 species‐specific abundance records, together with metadata related to the geographical location and sampling methodology of each time‐series.

Spatial location and grain

The database contains 11,072 unique sampling locations (stream reach), spanning 19 countries, five biogeographical realms and 402 hydrographical basins world‐wide.

Time period and grain

The database encompasses the period 1951–2019. Each time‐series is composed of a minimum of two yearly surveys (mean = 8 years) and represents a minimum time span of 10 years (mean = 19 years).

Major taxa and level of measurement

The database includes 944 species of ray‐finned fishes (Class Actinopterygii).

Software format

csv.

Main conclusion

Our collective effort provides the most comprehensive long‐term community database of riverine fishes to date. This unique database should interest ecologists who seek to understand the impacts of human activities on riverine fish biodiversity and to model and predict how fish communities will respond to future environmental change. Together, we hope it will promote advances in macroecological research in the freshwater realm.
Inflammation accelerates copper‐mediated cytotoxicity through induction of six‐transmembrane epithelial antigens of prostate 4 expression
Authors: Jiang Cen , Wu Beiying , Xue Minghui , Lin Jiafei , Hu Zhenli , Nie Xiaomeng , Cai Gang
Published: November 2020

Copper is an essential trace metal, but imbalance in copper homeostasis can induce oxidative damage. Inflammation is a fundamental element of various pulmonary diseases. Although a positive relationship between copper and chronic pulmonary diseases has been reported, the underlying reasons are still not clear. The copper level in the sputum of patients with various pulmonary diseases was measured. An inflammatory model was established to evaluate the impact of inflammation on copper uptake in the lung. We found that the level of sputum copper was increased in patients with various pulmonary diseases, especially chronic obstructive pulmonary disease and asthma. Then, we confirmed that mice with pulmonary inflammation were susceptible to copper‐mediated oxidative damage because of copper overload in lung tissue. Further investigation demonstrated that interleukin (IL)‐17 and tumor necrosis factor (TNF)‐α exerted synergistic effects in airway epithelial cells by upregulating the expression of six‐transmembrane epithelial antigens of prostate 4 (STEAP4), a metalloreductase that reduces extracellular copper ions from the cupric state to the cuprous state and facilitates copper uptake. Inhibition of STEAP4 decreased the copper uptake of cells and inhibited copper‐mediated oxidative damage. Moreover, we demonstrated that the upregulation of STEAP4 by IL‐17 and TNF‐α was largely dependent on TNF receptor‐associated factor 4 (TRAF4). Traf4−/− mice were resistant to copper‐mediated oxidative damage. Our data suggest a novel IL‐17/TNF‐α–TRAF4–STEAP4 axis that regulates copper homeostasis.
Fracture strength of various titanium‐based, CAD‐CAM and PFM implant crowns
Authors: DuVall Nicholas B. , DeReis Stephen P. , Vandewalle Kraig S.
Published: November 2020

Objective

CAD‐CAM has dramatically advanced dental restorative procedures to include implant‐supported crowns. The purpose of this study was to compare the fracture resistance following mechanical loading and thermocycling of various screw‐retained and cement‐retained ceramic and polymethylmethacrylate material combinations using the TiBase abutment compared to PFM implant‐supported crowns.

Overview

Twelve implant restorations were fabricated for each of eight groups. Three groups were screw‐retained and five groups were cement‐retained implant restorations. The ceramic and polymethylmethacrylate restorations were fabricated on the TiBase abutment while the PFM restorations were fabricated on an UCLA abutment. Data were analyzed with a one way Analysis of Variance and Tukey's post‐hoc test to evaluate the effect of abutment and crown type on fracture load (alpha = 0.05). A significant difference was found in the maximum fracture load between groups (P < 0.001).

Conclusions

The screw‐retained implant restorations demonstrated higher fracture loads than their cement‐retained counterparts. The TiBase abutment compared favorably to the UCLA abutment.

Clinical Significance

The TiBase abutment is a titanium insert which combines the esthetics of a ceramic abutment with the mechanical properties of a titanium abutment and should be considered a viable clinical alternative to the conventional implant‐supported PFM crown based on theses in vitro results and in context of in vivo studies. The lithium disilicate hybrid abutment/crown implant‐supported restoration utilizing the TiBase abutment may be an ideal clinical choice due to simplicity, single appointment CAD‐CAM, and esthetics.
Interdental papilla reconstruction using injectable hyaluronic acid: A 6 month prospective longitudinal clinical study
Authors: Alhabashneh Rola , Alomari Sawsan , Khaleel Bassam , Qinawi Haytham , Alzaubi Majdi
Published: November 2020

The objective of this study was to assess the efficacy of Hyaluronic Acid (HA) on interdental papilla (IDP) loss in the esthetic zone. Twenty one subjects (14 females and 7 males) from those referred for treatment of IDP loss at Periodontics postgraduate clinics at the Jordan University of Science and Technology. A total of 86 interdental sites (58 sites in the maxillary jaw and 28 sites in the mandibular jaw) were treated and followed up. A 0.2 ml of Hyaluronic acid was injected in each receded IDP site and injections were repeated after 21 days. Papilla sites were evaluated and statistically analyzed. At the 3 week interval the mean reduction of black triangle (BT) height was 0.17 mm (8% reduction) (P‐value <0.001), at the 3 month interval there was a mean reduction of BT height of 0.83 mm (39% reduction) (P‐value <0.001). At 6 months however, the reduction in BT height was 0.62 mm (29% reduction) (P‐value <0.001). Within the limitations of this study, it can be concluded that the use of commercially available HA gel for the treatment of interdental papillae loss may have promising results over the first 6 months after injection. The maximum improvement in black triangles was at 3 months after injection with a reduction of improvement between 3 and 6 months. Clinical Relevance Helping clinician to take evidence based decision while considering Hyaluronic acid injection as a short term nonsurgical treatment modality for interdental papilla loss.
Landscape genomics of Quercus lobata reveals genes involved in local climate adaptation at multiple spatial scales
Authors: Gugger Paul F. , Fitz‐Gibbon Sorel T. , Albarrán‐Lara Ana , Wright Jessica W. , Sork Victoria L.
Published: November 2020

Understanding how the environment shapes genetic variation provides critical insight about the evolution of local adaptation in natural populations. At multiple spatial scales and multiple geographic contexts within a single species, such information could address a number of fundamental questions about the scale of local adaptation and whether or not the same loci are involved at different spatial scales or geographic contexts. We used landscape genomic approaches from three local elevational transects and rangewide sampling to (a) identify genetic variation underlying local adaptation to environmental gradients in the California endemic oak, Quercus lobata; (b) examine whether putatively adaptive SNPs show signatures of selection at multiple spatial scales; and (c) map putatively adaptive variation to assess the scale and pattern of local adaptation. Of over 10 k single‐nucleotide polymorphisms (SNPs) generated with genotyping‐by‐sequencing, we found signatures of natural selection by climate or local environment at over 600 SNPs (536 loci), some at multiple spatial scales across multiple analyses. Candidate SNPs identified with gene–environment tests (LFMM) at the rangewide scale also showed elevated associations with climate variables compared to the background at both rangewide and elevational transect scales with gradient forest analysis. Some loci overlap with those detected in other oak species, raising the question of whether the same loci might be involved in local climate adaptation in different congeneric species that inhabit different geographic contexts. Mapping landscape patterns of adaptive versus background genetic variation identified regions of marked local adaptation and suggests nonlinear association of candidate SNPs and environmental variables. Taken together, our results offer robust evidence for novel candidate genes for local climate adaptation at multiple spatial scales.
Red Tape, Organizational Performance, and Employee Outcomes: Meta‐analysis, Meta‐regression, and Research Agenda
Authors: George Bert , Pandey Sanjay K. , Steijn Bram , Decramer Adelien , Audenaert Mieke
Published: November 2020

Although there is consensus among scholars that red tape has negative consequences, there is a lack of synthesis on these negative effects. We conduct a meta‐analysis and meta‐regression of public administration evidence and ask: What is the impact of red tape on organizational performance and employee outcomes, and which conditions moderate this impact? Our meta‐analysis finds that red tape has a significant, negative, and small‐to‐medium impact on both organizational performance and employee outcomes. Meta‐regression shows that red tape imposed by the organization itself is more harmful than red tape imposed by external parties. Moreover, red tape's negative impact remains quite stable across sectors, administrative traditions, and research methods. In conclusion, an agenda for future public administration research on red tape is presented. We recommend that future research syntheses on red tape include research on concepts that bear a family resemblance (e.g., sludge, administrative burden) and also encourage analyses of differing discourses to identify common themes.
Risks and outcomes of adenovirus disease in pediatric hematopoietic stem cell transplant recipients—Comparison of current antiviral treatment options
Authors: Thomas Sanya J. , Young Rebecca T. , Steinbach William J. , Lugo Debra J.
Published: November 2020

Background

Adenovirus disease (ADVd) is a significant burden in pediatric hematopoietic stem cell transplant (HSCT) recipients. However, current knowledge of risk factors associated with poor clinical outcome and the effectiveness of antiviral therapy are not well understood. This study determined the relationship between transplant characteristics and risk of ADVd and also compared time to resolution of disease between pediatric patients who did and did not receive antiviral therapy.

Methods

We conducted a retrospective, single‐center cohort study of pediatric patients undergoing HSCT at Duke University (2005‐2016). Cases of ADVd were defined a priori using a classification tool. Cox proportional hazards (CPH) regression models were used to compare the hazard of ADVd between HSCT recipients differing by type of transplant and type of conditioning regimen. The hazard of time to resolution of ADVd by antiviral therapy (cidofovir, brincidofovir, both, or neither) was compared.

Results

Ninety‐three of 830 subjects had ADVd post‐HSCT (11.2%). Umbilical cord transplant (UCT) recipients had 2.30 (95% CI 1.57, 6.90, P = .002) higher hazard of developing ADVd compared to non‐cord allogeneic transplants, and 6.30 higher (95% CI 2.70, 19.61, P < .001) hazard compared to autologous transplants. Subjects who did not receive antiviral therapy experienced earlier resolution of ADVd compared to subjects who received therapy, even after adjusting for subjects with disseminated disease (HR [95% CI]: 3.75 [1.57, 8.93], P = .003).

Conclusions

Pediatric UCT recipients are at a higher risk for ADVd. Antiviral therapy was not associated with an earlier resolution of ADVd, even in patients with higher disease burden.
Increased sympathetic and haemodynamic responses to exercise and muscle metaboreflex activation in post‐menopausal women with rheumatoid arthritis
Authors: Peçanha Tiago , Meireles Kamila , Pinto Ana Jéssica , Rezende Diego Augusto Nunes , Iraha Amanda Yuri , Mazzolani Bruna Caruso , Smaira Fabiana Infante , Sales Allan Robson Kluser , Bonfiglioli Karina , Sá‐Pinto Ana Lúcia de , Lima Fernanda Rodrigues , Irigoyen Maria Cláudia , Gualano Bruno , Roschel Hamilton
Published: November 2020

Key points

 Rheumatoid arthritis (RA) patients present exacerbated blood pressure responses to exercise, but little is known regarding the underlying mechanisms involved.

 This study assessed autonomic and haemodynamic responses to exercise and to the isolated activation of muscle metaboreflex in post‐menopausal women with RA.

 Participants with RA showed augmented pressor and sympathetic responses to exercise and to the activation of muscle metaboreflex. These responses were associated with multiple pro‐ and anti‐inflammatory cytokines and with pain.

 The results of the present study support the suggestion that an abnormal reflex control of circulation is an important mechanism underlying the exacerbated cardiovascular response to exercise and increased cardiovascular risk in RA.

Studies have reported abnormal cardiovascular responses to exercise in rheumatoid arthritis (RA) patients, but little is known regarding the underlying mechanisms involved. This study assessed haemodynamic and sympathetic responses to exercise and to the isolated activation of muscle metaboreflex in women diagnosed with RA. Thirty‐three post‐menopausal women diagnosed with RA and 10 matched controls (CON) participated in this study. Mean arterial pressure (MAP), heart rate (HR) and muscle sympathetic nerve activity (MSNA frequency and incidence) were measured during a protocol of isometric knee extension exercise (3 min, 30% of maximal voluntary contraction), followed by post‐exercise ischaemia (PEI). Participants with RA showed greater increases in MAP and MSNA during exercise and PEI than CON (ΔMAPexercise = 16 ± 11 vs. 9 ± 6 mmHg, P = 0.03; ΔMAPPEI = 15 ± 10 vs. 5 ± 5 mmHg, P = 0.001; ΔMSNAexercise = 17 ± 14 vs. 7 ± 9 bursts min–1, P = 0.04; ΔMSNAPEI = 14 ± 10 vs. 6 ± 4 bursts min–1, P = 0.04). Autonomic responses to exercise showed significant (P < 0.05) association with pro‐ (i.e. IFN‐γ, IL‐8, MCP‐1 and TNFα) and anti‐inflammatory (i.e. IL‐1ra and IL‐10) cytokines and with pain. In conclusion, post‐menopausal women with RA showed augmented pressor and sympathetic responses to exercise and to the activation of muscle metaboreflex. These findings provide mechanistic insights that may explain the abnormal cardiovascular responses to exercise in RA.
Integration of Data Management Systems With an Ontology Based Information Management System
Authors: Wijnker T. C. , Lutters D. , van Houten F. J. A. M. , Kals H. J. J.
Published: November 2020

In analyzing design and manufacturing tasks and their mutual interactions, it appears that the underlying information of these tasks is of the utmost importance. If this information is managed on an integral level, in a formalized, structured way, it can serve as a basis for the control of design and manufacturing processes. The ontological description that is used for this purpose is elaborated upon. It is indicated how an ontological description of the information content can govern design and manufacturing processes, and support their execution with all required information and functionality of resources. Moreover, it is expound how the ontological description can serve as the basis for integrating information that, in industry, is often dispersedly managed in separate coexisting data management systems. Furthermore, a framework is proposed for the implementation of an Information Management system as well as for the additional applications that utilize its functionality. Finally, a pilot implementation at a large Dutch industrial company is discussed concerning the aspect of integrating dispersedly managed information. This implementation is also compared to some currently available commercial solutions in this area that were tested at the company as well.
Topology Synthesis of Electrothermal Compliant (ETC) Mechanisms Using Line Elements
Authors: Mankame Nilesh D. , Ananthasuresh G. K.
Published: November 2020

This paper presents a line element based approach to the synthesis of electrothermally actuated compliant (ETC) mechanisms. A line element is a one-dimensional model of the electrical, thermal and elastic behavior of a beam-like continuum. In contrast to topology synthesis of ETC mechanisms by a continuum element based approach, the line element based approach offers significant conceptual and practical advantages. The line element approach allows for accurate modeling of surface heat transfer in a straightforward manner. Moreover, this approach results in clean geometries that are easy to fabricate. The line element based ETC mechanism synthesis procedure is used to study the influence of the direction of output and the electrical and thermal resistance of the workpiece on the resulting optimal topology. Solutions obtained from this procedure are compared with results from continuum based optimal synthesis procedures as well as intuitive designs reported in literature. The ability of the procedure to generate non-intuitive topologies is also demonstrated through design examples.
Global System Optimization Using Hierarchical Genetic Algorithms Based on Decision-Making Components
Authors: Yoshimura Masataka , Izui Kazuhiro
Published: November 2020

The efficient, optimized manufacture of sophisticated products largely depends upon a globally optimized design and manufacturing solution. Ideally, the decision-making tools independently used within various enterprise divisions, such as design and manufacturing, should be integrated, and all decisions made should take into account the goal of global optimization of the entire system. This paper proposes an integrated global optimization technique especially suited to systems consisting of multiple divisions. Each division’s decision-making tools are transformed into components, the interrelationships of these components and other decision variables are classified, and an optimization problem is formulated based on these classifications. The obtained optimization problem is constructed from hierarchically structured decision variables, and the optimization problem is represented by hierarchical genes. Finally, to achieve a globally optimal solution, a hybrid optimization method is demonstrated, that uses a combination of hierarchical genetic algorithms in concert with the optimization methods attached to divisional decision-making components.
Gradation of Planar Mechanism Structures for Robot Arms Based on Their Structural Error Performance
Authors: Pathapati V. V. N. R. Prasad Raju , Rao A. C.
Published: November 2020

Robot arms which received greater attention in the recent past are open chain linkages. Each joint in these robot arms, is actuated independently. While possessing many advantages such as large workspace and maneuverability, they do suffer from disadvantages like less rigidity, accumulation of mechanical errors from shoulder to end effector, control problems etc. The alternative to the open chain robot arms is the in-parallel actuator arrangement often referred to as the platform-type whose successful application is reported by many investigators. Multi-degree-of-freedom Mechanisms are now receiving active consideration for application as platform type robots. In fact in the literature, a number of distinct multi degree of freedom planar linkage mechanisms are available and all of them can be considered as platform type Robots. In this paper numerical measures are proposed to compare all the distinct planar linkage mechanisms at the conceptual stage of design in the category of 9 link, 2 degree of freedom and 10 link, 3 degree of freedom, from the view point of structural error performance. The proposed method is based on the deployment of design parameters in different topological features of the chain Viz., links, Joints and loops.
Derivation of Analytical Expressions for Calculation of AGMA Geometry Factor J for External Spur Gears
Authors: Arikan M. A. Sahir
Published: November 2020

Analytical expressions for calculation of AGMA geometry factor J are derived for external spur gears. Thus, it is made possible to evaluate the J factor easily and with minimum process time for computerized gear analysis and design applications. A computer program is developed to demonstrate the usage of the derived expressions.
Predicting Change Propagation in Complex Design
Authors: Clarkson P. John , Simons Caroline , Eckert Claudia
Published: November 2020

In redesign and design for customization, products are changed. During this process a change to one part of the product will, in most cases, result in changes to other parts. The accurate prediction of this change propagation provides a significant challenge in the management of redesign and customization. This paper reports on an analysis of change behavior based on a case study in GKN Westland Helicopters of rotorcraft design; the development of mathematical models to predict the risk of change propagation in terms of likelihood and impact of change; and the development of a prototype computer support tool.
Engineering Design in New Zealand: Introducing Internet Based Design at Canterbury
Authors: Gooch Shayne , Hales Crispin , Raine John
Published: November 2020

In this paper it is proposed that more emphasis be placed on promoting an entrepreneurial spirit amongst undergraduate students in their final year of study. This is to be achieved through an updated approach to design teaching and by setting projects that have good commercial viability. The aim is to produce graduate engineers with exceptional design and communication skills that they can market competitively around the globe.
Wavelet Transform of Sound Signal in Fluid-Filled Viscoelastic Pipes
Authors: Prek Matjaz
Published: November 2020

In viscoelastic pipes, where the material properties depends on a complex bulk modulus as well as on a complex shear modulus, the sound field within the fluid is affected. Therefore, the dispersion of flexural waves occurs in the pipe, while the speed of flexural waves decreases due to the coupled fluid mass. Coupling between the pipe wall and the fluid as decreases the sound speed in the fluid. Likewise, the speed of sound in fluid is frequency-dependent, just as the group velocity of bending waves depends on the frequency. Wavelet transform of non-stationary sound signal was used to identify the frequency-dependent fluid sound speed. A time-frequency map, constructed by plotting the wavelet coefficient against the translation and scale parameters, shows an alteration in the low frequency waves. The so called “fluid mode” and “pipe mode” resonant frequencies are also clearly evident. Lastly, the impact of different pipe wall material properties is also shown. Wavelet analysis of the measured impulse response of a fluid-filled viscoelastic pipe provides useful tool for investigating its acoustical properties.
Auto-Balance Anisotropic Mounted Rotors
Authors: Wettergren Håkan L.
Published: November 2020

By using balancing balls constrained to move in a circular groove filled with oil, it is possible to reduce, under certain circumstances, the vibration of rotating machinery.

The critical ball-damping ratio is highest just above the natural frequency, after which it rapidly decreases. Consequently, since the interval between instability and critical damping is quite small, the ball damping should be as small as possible without getting too close to the instability threshold. If the rotational frequency is lower than the first eigenfrequency the balls stay together near 0°. Passing the first critical speed the balls almost immediately find the stable position.

Just before the second critical speed, the balls cannot find a steady-state position but simply rotate in the circular groove. Prior to that, the balls find another stable position, which is different from the one that eliminates the mass unbalance.
Active Mass Auto-Balancing System for Centrifuge Rotor Providing an Artificial Gravity in Space
Authors: Ohtomi Koichi , Otsuki Fumio , Uematsu Hirohiko , Nakamura Yasuhiro , Chida Yuichi , Nishimura Osamu , Okamura Ryo
Published: November 2020

The Centrifuge Rotor (CR) is an artificial gravity generator, which is aiming at launch in 2006 as a portion of the life science experimental facility of the International Space Station (ISS). The CR rotates habitats located radially around the axis and generates centrifugal force, imposing artificial gravity of arbitrary magnitude up to 22.0 m/s2 (about 2.2 g) on the specimens housed in the habitats. The imbalance is caused by the asymmetry of two habitats opposite each other, which brings about change in the mass of the habitats as well as the quasi-static change of the CG of plants and fluids and the dynamic rodent motions in the habitats. The active mass Auto-Balancing System (ABS) is provided for automatic canceling of the above-mentioned imbalance of the rotor. This paper presents the concept and the test results of the ABS.
Pattern Formation in a Parametrically-Excited P.D.E.
Authors: Stubna Michael D. , Rand Richard H.
Published: November 2020

We investigate the dynamics of the parametrically-excited P.D.E.(1)∂2u∂t2-c2(∂2u∂x2+∂2u∂y2)+εβ∂u∂t+(∂+εγcos⁡t)u=εαu3 with Neumann boundary conditions on a rectangular region:∂u∂x=0forx=0,π and ∂u∂y=0fory=0,πμ where 0 < μ ≤ 1. Our approach involves expanding u(x, y, t) in a 3-term Fourier series truncation:(2)u=f0(t)+f1(t)cos⁡x+f2(t)cos⁡μy By substituting (2) into (1) we obtain a system of 3 coupled nonlinear Mathieu equations which we analyze using averaging in the neighborhood of 2 : 1 resonance.

By varying the parameters c and δ we obtain bifurcation curves which divide the cδ-plane into more than forty regions, each containing a distinct slow flow. Individual regions are found to differ from one another with respect to such features as the number and character of slow flow equilibria, and the presence or absence of a limit cycle. When interpreted in the original variable u, these regions account for a variety of patterns which may be classified as stationary, traveling or rotating.

This type of behavior is comparable to various experimental observations made by other investigators on vertically driven fluids or sand.
Optimal Control Design of a Bimorph Optical Beam Deflector
Authors: Chao Chang-Po , Huang Jeng-Sheng , Yung Ching-Lung Ou , Fung Rong-Fong
Published: November 2020

The optical beam deflector is composed of two piezoelectric layers, one sandwiched brass layer in the middle with both ends clamped and a mirror attached to the upper surface of the top piezoelectric layer in the central position. This structure is designed to deflect the mirror to a certain angular position by applying external voltage supply to piezo-layers. This study proposes an optimal angular position control scheme of the attached mirror. The governing partial differential equations are first derived for the ensuing analysis and control design, which is followed by the establishment of finite element model in ten nodes specified at some longitudinal points of the optical beam deflector. In order to achieve a faster convergent rate for the deflector to reach the desired angular position, the optimal control of LQ regulator with final states fixed is employed to explore the possibility of shorter transient response and less cost of control effort and states. The optimal feedback control is obtained based on solving a dynamic Riccati equation backward in time. The numerical simulation results are finally provided to validate the theoretical control design.
An Investigation of a Rocking-Sliding Block
Authors: Virgin L. N. , Aldemir U. , Gavin H. P. , Nichols J. M. , Plaut R. H.
Published: November 2020

The short end of a rigid rectangular block with a 2:1 aspect ratio is placed on a flat horizontal surface. The surface exhibits a horizontal harmonic motion, and two-dimensional motions of the block are investigated numerically and experimentally. A variety of modes of behavior are possible, and, when viewed from the side, attention is focused on (a) rocking of the block about either bottom corner or (b) sliding while rocking about one of those corners. Different periodic or erratic rocking-sliding responses are observed, with overturning being one of the possible outcomes. This system has relevance to a number of practical applications, especially in the context of earthquake engineering.

The experiment consists of two aluminum blocks separated by a heavy steel cylinder. It is mounted on a shake table that oscillates harmonically in the horizontal direction. Data are acquired using image video processing with a number of targets mounted on the block face. Two guides are used to ensure that the motion remains in the vertical plane. Reasonable qualitative agreement between simulations and experimental data is achieved, especially when viewed within the context of highly nonlinear systems and their inherent sensitivity. This work may be considered as an extension to our previous work (Fielder et al., 1997), with the addition of sliding being the major new ingredient.
Feasibility of Two-Dimensional Control for Ship-Mounted Cranes
Authors: Abdel-Rahman Eihab M. , Nayfeh Ali H.
Published: November 2020

We test the feasibility of employing an exclusively planar control effort to suppress unsafe ship-mounted crane pendulations induced by sea motions. The new crane configuration, designed to apply the control effort, is modeled and the proposed control effort, employing Coulomb friction and viscous damping, is applied. The three-dimensional nonlinear dynamics of the crane is then investigated.

The new crane configuration, dubbed Maryland Rigging, transforms a crane from a single spherical pendulum to a double pendulum system. The upper pendulum, a pulley riding on a cable suspended from the boom, is constrained to move over an ellipsoid. The major axis of the ellipsoid is the boom and the foci are the two points at which the riding cable attaches to it. The lower pendulum, the payload suspended by a cable from the pulley, continues to act as a spherical pendulum. Due to the geometry of the ellipsoid, the natural frequencies of the crane in the plane of the boom (in-plane) are almost equal to the out-of-plane natural frequencies.

The model is used to examine the response of a Maryland rigged crane to direct, in-plane, harmonic forcing. The frequency of the excitation is set almost equal to the crane’s lowest natural frequency. It is found that under this excitation and due to the one-to-one internal resonance between the lowest in-plane and out-of-plane natural frequencies, significant out-of-plane motions are induced by applying a purely in-plane forcing. Thus an in-plane control mechanism is not adequate for safe operation of the crane. To guarantee safe operation of a ship-mounted crane, one must apply both in-plane and out-of-plane control efforts.
Effect of Piezoceramic Hysteresis in Passive and Hybrid Structural Acoustic Control
Authors: Ozer M. Bulent , Royston Thomas J.
Published: November 2020

Structural acoustic control via passive and hybrid electrical shunting of a piezoceramic wafer bonded onto the surface of a simply supported plate is investigated with emphasis on modeling and understanding the effect of piezoceramic nonlinearity on system performance. A nonlinear rate-independent finite-dimension Ishlinskii hysteresis model is experimentally identified for the PZT wafer by itself and then integrated into the coupled dynamic equations of the overall system consisting of the plate and electrically shunted PZT wafer. This model is then used to investigate the impact of PZT hysteresis on its structural acoustic control performance in passive and hybrid scenarios. A multi-term describing function representation of the Ishlinskii hysteresis model is formulated to aid in computational studies.
Identifying Coulomb and Viscous Friction in Forced Dual-Damped Oscillators
Authors: Liang J.-W. , Feeny B. F.
Published: November 2020

This paper presents a method for estimating Coulomb and viscous friction coefficients from responses of an harmonically excited dual-damped oscillator. The identification method is based on analytical solutions of non-sticking responses excited near the natural frequency. It is applicable if the damping ratio of the viscous component can be considered small. The Coulomb and viscous friction parameters can be extracted from two or more input-output amplitude pairs at resonance. The method is tested numerically and experimentally. Experimental results are cross checked with estimations from free-vibration decrements and also from friction measurements.