bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of dense polymer‐derived silicon carbonitride ceramic bulks by precursor infiltration and pyrolysis processes without losing piezoresistivity
Authors: Ma Baisheng , Wang Yiguang
Published: January 2018

Dense polymer‐derived silicon carbonitride (SiCN) ceramic bulks were fabricated by powder consolidation following precursor infiltration and pyrolysis (PIP) densification. The density and open porosity of the ceramics varied from 1.42 g/cm3 and 32.75% before the PIP to 2.29 g/cm3 and 3.64% after the PIP, respectively. The electrical conductivity of the ceramics sharply increased from 6.26 × 10−10 S/cm before the PIP process to 3.20 × 10−7 S/cm after the 1st cycle of PIP and then gradually increased to 6.89 × 10−6 S/cm after four cycles of PIP. However, the piezoresistive coefficient did not change with the PIP. The Raman and electron paramagnetic resonance results show that the graphitization level of free carbon in ceramics derived from PIP was higher than the ceramics derived from powder consolidation. The high graphitization level of free carbon leads to a high conductivity, and thus the conductivity of ceramics increased significantly after the PIP process. The carbon cluster size, which is related to the gauge factor of piezoresistivity, did not change significantly after the PIP process; thus, the gauge factor did not change significantly. Dense, large‐scale polymer‐derived ceramics were fabricated by combined conventional powder consolidation and PIP without the loss of piezoresistivity. These ceramics have potential application as both structural and functional components that can bear loads as well as monitor variations in external stress.
Realism and Pragmatism in a mixed methods study
Authors: Allmark Peter , Machaczek Katarzyna
Published: January 2018

Aim

A discussion of how adopting a Realist rather than Pragmatist methodology affects the conduct of mixed methods research.

Background

Mixed methods approaches are now extensively employed in nursing and other healthcare research. At the same time, realist methodology is increasingly used as philosophical underpinning of research in these areas. However, the standard philosophical underpinning of mixed methods research is Pragmatism, which is generally considered incompatible or at least at odds with Realism. This paper argues that Realism can be used as the basis of mixed methods research and that doing so carries advantages over using Pragmatism. A mixed method study into patient handover reports is used to illustrate how Realism affected its design and how it would have differed had a Pragmatist approach been taken.

Design

Discussion Paper.

Data sources

Philosophers Index; Google Scholar.

Implications for nursing

Those undertaking mixed methods research should consider the use of Realist methodology with the addition of some insights from Pragmatism to do with the start and end points of enquiry.

Conclusion

Realism is a plausible alternative methodology for those undertaking mixed methods studies.
The existential experience of everyday life with systemic lupus erythematosus
Authors: Larsen Janni Lisander , Hall Elisabeth O. C. , Jacobsen Søren , Birkelund Regner
Published: January 2018

Aim

To explore from the perspective of women the nature of basic existential conditions while living with systemic lupus erythematosus.

Background

Systemic lupus erythematosus has an unpredictable disease course and is documented to cause an existential rearrangement of life. The significance of changes in existential conditions and related experiences are unclear in the context of nursing and women with systemic lupus erythematosus.

Design

A qualitative design guided by Van Manen's hermeneutic‐phenomenological methodology.

Method

Individual in‐depth interviews with 15 women diagnosed with systemic lupus erythematosus and of various ages, disease durations and severities were undertaken from September 2013 ‐ October 2015. Data were analysed following van Manen's phenomenological approach and using drawing as an interpretive tool.

Findings

The main existential experience was interpreted as a person “moving with the waves of systemic lupus erythematosus” constituted by the themes “oscillating between presence and absence of systemic lupus erythematosus,” “recognizing space and bodily possibilities and limitations” and “being enriched through relationships and activities.” When systemic lupus erythematosus was flaring, well‐being was threatened and a laborious time to escape the feeling of a setback‐in‐life persisted long after the disease was medically under control.

Conclusion

Daily life with systemic lupus erythematosus is conditioned by a prominent need to be in existential motion, related to the absence and presence of systemic lupus erythematosus. The experience of a setback‐in‐life by illness might challenge well‐being and indicates that periods of disease flares or disturbing symptoms are critical time points to provide support.
An evolutionary concept analysis of futility in health care
Authors: Morata Lauren
Published: January 2018

Aim

To report a concept analysis of futility in health care.

Background

Each member of the healthcare team: the physician, the nurse, the patient, the family and all others involved perceive futility differently. The current evidence and knowledge in regard to futility in health care manifest a plethora of definitions, meanings and interpretations without consensus.

Design

Concept analysis.

Data Sources

Databases searched included Medline, Cumulative Index of Nursing and Allied Health Literature, Academic Search Premier, Cochrane Database of Systematic Reviews and PsycINFO. Search terms included “futil*,” “concept analysis,” “concept,” “inefficacious,” “non‐beneficial,” “ineffective” and “fruitless” from 1935–2016 to ensure a historical perspective of the concept. A total of 106 articles were retained to develop the concept.

Methods

Rogers’ evolutionary concept analysis was used to evaluate the concept of futility from ancient medicine to the present.

Results

Seven antecedents (the patient/family autonomy, surrogate decision‐making movement, the patient–family/physician relationship, physician authority, legislation and court rulings, catastrophic events and advancing medical technology) lead to four major attributes (quantitative, physiologic, qualitative, and disease‐specific). Ultimately, futile care could lead to consequences such as litigation, advancing technology, increasing healthcare costs, rationing, moral distress and ethical dilemmas.

Conclusion

Futility in health care demonstrates components of a cyclical process and a consensus definition is proposed. A framework is developed to clarify the concept and articulate relationships among attributes, antecedents and consequences. Further testing of the proposed definition and framework are needed.
GP73 promotes invasion and metastasis of bladder cancer by regulating the epithelial–mesenchymal transition through the TGF‐β1/Smad2 signalling pathway
Authors: Yang Han‐Jie , Liu Ge‐Liang , Liu Bo , Liu Tian
Published: January 2018

This study investigated the effects of Golgi membrane protein 73 (GP73) on the epithelial–mesenchymal transition (EMT) and on bladder cancer cell invasion and metastasis through the TGF‐β1/Smad2 signalling pathway. Paired bladder cancer and adjacent tissue samples (102) and normal bladder tissue samples (106) were obtained. Bladder cancer cell lines (T24, 5637, RT4, 253J and J82) were selected and assigned to blank, negative control (NC), TGF‐β, thrombospondin‐1 (TSP‐1), TGF‐β1+ TSP‐1, GP73‐siRNA‐1, GP73‐siRNA‐2, GP73‐siRNA‐1+ TSP‐1, GP73‐siRNA‐1+ pcDNA‐GP73, WT1‐siRNA and WT1‐siRNA + GP73‐siRNA‐1 groups. Expressions of GP73, TGF‐β1, Smad2, p‐Smad2, E‐cadherin and vimentin were detected using RT‐qPCR and Western blotting. Cell proliferation, migration and invasion were determined using MTT assay, scratch testing and Transwell assay, respectively. Compared with the blank and NC groups, levels of GP73, TGF‐β1, Smad2, p‐Smad2, N‐cadherin and vimentin decreased, and levels of WT1 and E‐cadherin increased in the GP73‐siRNA‐1 and GP73‐siRNA‐2 groups, while the opposite results were observed in the WT1 siRNA, TGF‐β, TSP‐1 and TGF‐β + TSP‐1 groups. Cell proliferation, migration and invasion notably decreased in the GP73‐siRNA‐1 and GP73‐siRNA‐2 groups in comparison with the blank and NC groups, while in the WT1 siRNA, TGF‐β, TSP‐1 and TGF‐β + TSP‐1 groups, cell migration, invasion and proliferation showed the reduction after the EMT. These results suggest that GP73 promotes bladder cancer invasion and metastasis by inducing the EMT through down‐regulating WT1 levels and activating the TGF‐β1/Smad2 signalling pathway.
Where Less Is More: Reducing Variable Annuity Fees to Benefit Policyholder and Insurer
Authors: Bernard Carole , Moenig Thorsten
Published: January 2018

In the United States, variable annuities (VAs) are popular long‐term personal investment vehicles. Recently, however, sales have begun to dwindle. In fact, financial advisers have long argued against investing in VAs due to the products’ high fees. VA providers charge these fees—typically at a constant rate throughout the policy period—to cover their expenses and the costs of embedded guarantees, and lowering this constant fee rate could make the VA unprofitable. Instead, we propose and analyze a simple change to the fee “structure” that would lower fee rates overall (and thus make the product more attractive to investors) without reducing the insurer's profit. The key insight is that this time‐dependent fee rate (with moderate front‐loading) implicitly discourages policy lapses and exchanges, which reduces the providers’ policy acquisition expenses. Taking into account financially optimal lapse (and reentry) decisions, we determine the optimal timing and rate of the fee reduction for a competitive as well as for an innovative VA provider. An important characteristic of this feature is that it can be implemented easily and effectively to both new and existing VA policies.
Validation of the hedonic threshold methodology in determining the hedonic rejection threshold
Authors: Lima Filho Tarcísio , Della Lucia Suzana Maria , Minim Luis Antônio , Silva Rita de Cássia dos Santos Navarro da , Minim Valéria Paula Rodrigues
Published: January 2018

The hedonic thresholds methodology was recently proposed which allows for determination of two new sensorial thresholds, the compromised acceptance threshold and the hedonic rejection threshold (HRT). For a new methodology to be accepted by the scientific community, its ability to produce reliable results must be demonstrated. Thus, this study sought to validate this new methodology when used to calculate the HRT. In order to do so, the analytical performance indices of precision (repeatability, intermediate precision, and reproducibility), accuracy and robustness for the results for the HRT calculation were measured. The results of seven experiments demonstrated that the methodology possesses high repeatability, intermediate precision and robustness, and satisfactory accuracy and reproducibility. It was therefore concluded that the HRT determination methodology satisfactorily met the analytical performance criteria evaluated, therefore generating reliable results.

Practical applications

The hedonic thresholds methodology (HTM) has numerous applications, including the application of a more severe thermal treatment to obtain greater microbial or enzymatic inactivation, the determination of food shelf life based on its sensory acceptance, the reduction of specific, expensive ingredients in food formulations, reduction of ingredients that are harmful to health when consumed in excess (e.g., sucrose, sodium, and fat), determination of the maximum “defect” threshold that may be present in food and others. The HTM is a recently proposed methodology; therefore, the reliability of the values of the hedonic rejection threshold must be validated, calculated via the HTM. Reliability of the HRT results was confirmed when HTM validation was performed. Thus, the methodology can undoubtedly be applied for the intended purpose.
Victorian media studies, history, and theory
Authors: Wong Amy R.
Published: January 2018

This article gives an account of Victorian media studies as a sub‐field that emerged primarily from investigations of nineteenth‐century communication technologies and the century's accompanying preoccupations with transmission and the idea of in‐betweenness. Owing to unprecedented developments such as the rise of the universal postal system, telegraphy, phonography, photography, and mass print media, historicist inquiries have proven fruitful for the sub‐field. At the same time, continuities between how Victorians (such as the journalist and editor W. T. Stead) imagined communication's unifying reach across Britain and the globe and twentieth‐century media theory's critique of this same reach have ensured the sub‐field's grounding in theoretical engagements. The second part of the article considers how alternative frameworks for understanding media beyond communication (such as immersion, virtuality, and media archaeology) are currently redefining Victorian media studies in the twenty‐first century, continuing the sub‐field's robust dialectical engagements of history and theory.
Intraosseous mandibular xanthomas – an interesting diagnostic dilemma?
Authors: Whitehouse L.L.E. , Bobinskas A.M. , Chengot P. , Ong T.K.
Published: January 2018

Intraosseous xanthomas are rare, benign entities and may present a diagnostic challenge to clinicians, radiologists and histopathologists due to the non‐specific features of this lesion. Presented here is the first definitive reported recurrence of an intraosseous xanthoma, which was previously diagnosed as a granular cell odontogenic tumour. We include a review of the existing literature and discuss the diagnostic pitfalls in navigating the differences between granular cell odontogenic tumour and intraosseous xanthoma.
Mirror neurons and intention understanding: Dissociating the contribution of object type and intention to mirror responses using electromyography
Authors: Ruggiero Maura , Catmur Caroline
Published: January 2018

Since their discovery in the monkey and human brain, mirror neurons have been claimed to play a key role in understanding others' intentions. For example, “action‐constrained” mirror neurons in inferior parietal lobule fire when the monkey observes a grasping movement that is followed by an eating action, but not when it is followed by a placing action. It is claimed these responses enable the monkey to predict the intentions of the actor. These findings have been replicated in human observers by recording electromyography responses of the mouth‐opening mylohyoid muscle during action observation. Mylohyoid muscle activity was greater during the observation of actions performed with the intention to eat than of actions performed with the intention to place, again suggesting an ability to predict the actor's intentions. However, in previous studies, intention was confounded with object type (food for eating actions, nonfood for placing actions). We therefore used electromyography to measure mylohyoid activity in participants observing eating and placing actions. Unlike previous studies, we used a design in which each object (food, nonfood) could be both eaten and placed, and thus participants could not predict the actor's intention at the onset of the action. Greater mylohyoid activity was found for the observation of actions performed on food objects, irrespective of intention, indicating that the object type, not the actor's intention, drives the mirror response. This result suggests that observers' motor responses during action observation reflect the presence of a particular object, rather than the actor's underlying intentions.
The Ethical Foundations of Risk Analysis
Authors: Rozell Daniel J.
Published: January 2018

In the field of risk analysis, the normative value systems underlying accepted methodology are rarely explicitly discussed. This perspective provides a critique of the various ethical frameworks that can be used in risk assessments and risk management decisions. The goal is to acknowledge philosophical weaknesses that should be considered and communicated in order to improve the public acceptance of the work of risk analysts.
Border carbon adjustments and unilateral incentives to regulate the climate
Authors: Sanctuary Mark
Published: January 2018

It is suggested that trade measures should be used to induce exporters to adopt more ambitious climate policy and reduce global emissions. However, a tariff and the exporter's emission tax are likely substitutes, which would undermine the rationale for these trade measures. This paper examines incentives to regulate the climate under border carbon adjustment (BCA), defined as an import duty of a magnitude determined by the difference in emission taxes between trade partners. Unlike a tariff, a BCA can induce the exporter to adopt a higher tax, suggesting that the BCA and tariff are not equally effective at targeting global emission levels and that the features of the border measure matter in assessing the effectiveness of trade policy in targeting global emissions.
Blue Monday Is Real for Suicide: A Case–Control Study of 188,601 Suicides
Authors: Kim Eunkyong , Cho Seo‐Eun , Na Kyoung‐Sae , Jung Han‐Yong , Lee Kang‐Joon , Cho Seong‐Jin , Han Dae‐Guen
Published: January 2018

Many studies have reported that suicides tend to occur on Mondays. However, owing to a lack of controls, conclusive findings on the potential effects of a day of the week on suicides have been lacking. We analyzed public data for causes of death from 1997 to 2015 in the Republic of Korea. Accidental death was used as a control group. The probability of suicide on each day of the week according to age group was calculated. A total of 377,204 deaths (188,601 suicides and 188,603 accidental deaths) were used. The frequency of suicide was highest on Monday and decreased throughout the week until Saturday. Accidental death was highest on Saturday and showed no variations according to weekday. For people in their teens and 20s, the probabilities of suicide on Monday were 9% and 10% higher, respectively, than those on Sunday. As age increased, the differences in suicide probability according to the day of the week were attenuated. The so‐called Blue Monday effect is real, particularly for people in their teens and 20s. Suicide prevention strategies that aim to attenuate the burden and stress of Mondays should be planned.
Unsociability in Chinese adolescents: Cross‐informant agreement and relations with social and school adjustment
Authors: Zhang Linlin , Eggum‐Wilkens Natalie D.
Published: January 2018

We examined cross‐informant agreement of unsociability and associations of unsociability with social and school adjustment. Participants were 229 (48% girls; Mage = 14.25, SD = .78 years) seventh‐ and eighth‐graders in Liaoning, China. Unsociability and shyness were assessed with self‐reports and peer nominations. Social and school adjustment data were obtained from multiple sources (self‐, peer‐, teacher‐reports). Peer‐reported unsociability was not significantly correlated with self‐reported unsociability, but was positively correlated with self‐reported shyness. Path models indicated that controlling for shyness and demographic covariates, peer‐, but not self‐reported, unsociability was associated with low peer acceptance, high peer rejection and exclusion, low school liking, and low academic performance and achievement. The findings suggest that unsociable Chinese adolescents may have multifaceted adjustment difficulties with peers and at school, but only when perceived as unsociable by peers. Methodological and theoretical implications of the results and the lack of correspondence between self‐ and peer‐reports were discussed.
Transplanting corporate culture across international borders: Foreign direct investment and female employment in Japan
Authors: Kodama Naomi , Javorcik Beata S. , Abe Yukiko
Published: January 2018

This paper examines the effect of foreign ownership on gender‐related employment outcomes and work practices in Japan. The data indicate that the proportion of females among workers, managers, directors and board members is higher in foreign affiliates than in domestic firms of comparable size operating in the same industry. Foreign affiliates are also more likely to offer flexible working arrangements, telecommuting and childcare subsidies as well as employ foreign workers. These effects are visible almost exclusively in older affiliates. The analysis of foreign acquisitions combining propensity score matching with a difference in differences suggests that increase in the female labour share takes place a few years after the ownership change. All these patterns are in line with the view that it takes time to transplant corporate culture to an overseas affiliate.
Pharmacokinetic evaluation and safety of topical 1% morphine sulfate application on the healthy equine eye
Authors: Gordon Emma , Stang Bernadette V. , Heidel Jerry , Poulsen Keith P. , Cebra Christopher K. , Schlipf John W.
Published: January 2018

Objective

To determine if corneal epithelial cell integrity is detrimentally affected by short‐term administration of 1.0% morphine sulfate. Additionally, we sought to determine if topical 1.0% morphine applied to the equine cornea would result in ocular or systemic absorption.

Animal studied

Six healthy horses.

Procedure

Morphine sulfate (1.0%) was applied topically to one eye every four hours for 72 h before horses were euthanized. Serum samples were collected at varying time points during the study and aqueous and vitreous humor were collected immediately after euthanasia. Morphine quantification in serum, aqueous, and vitreous humor was performed by ELISA. Treated and control corneas were submitted for histopathology. Horses were monitored for adverse ocular and systemic effects throughout the study period.

Results

All horses developed mild mucoid ocular discharge in the treated eye. One horse developed a fever during treatment. Morphine was detected in the aqueous humor of the treated eye for all horses with mean ± standard deviation of 165.18 ng/mL ± 87.69 ng/mL. Morphine was detected in vitreous humor of the treated eye of 5 of 6 horses with mean ± standard deviation of 4.87 ± 4.46 ng/mL. Morphine was detected in the serum of 5 of 6 horses at varying time points. Maximum systemic concentration reached in a single horse was 6.98 ng/mL. Corneal histopathology revealed no difference in microscopic appearance between morphine‐treated and control corneas.

Conclusions

Topical administration of 1.0% morphine sulfate did not appear to cause any significant ocular or systemic adverse effects. Topical ophthalmic morphine application resulted in both ocular and systemic absorption.
Genetic structuring and diversity patterns along rivers – local invasion history of Ambrosia artemisiifolia (Asteraceae) along the Danube River in Vienna (Austria) shows non‐linear pattern
Authors: Kropf M , Huppenberger A S , Karrer G
Published: January 2018

Ambrosia artemisiifolia is an annual weed from North America that nowadays is invasive in many countries worldwide. In Austria, numerous populations of A. artemisiifolia are located along the Danube River, especially along the ‘New Danube’ (Vienna). This area is characterised by ruderal and riparian sites, which are regularly flooded. To better understand the spread of A. artemisiifolia and its colonising behaviour along the Danube River, we analysed genetic structure and diversity based on 23 populations linearly arranged along the Viennese Danube riverbed and upstream, utilising the Amplified Fragment Length Polymorphism (AFLP) fingerprint method. We generated 284 polymorphic AFLP markers across 446 A. artemisiifolia plants. The genetic diversity within populations was higher (HW = 0.091) than among populations (HB = 0.007). This result indicates A. artemisiifolia introductions from similar mixtures of sources or spread from a single already mixed introduction. Within our local setting, we were unable to identify neither source or sink populations nor an obvious linear genetic structuring. Genetic among‐population differentiation was low to moderate (amova‐derived FST = 0.124). Lack of geographical structuring is indicative of highly dynamic gene flow, which is further supported by the absence of an isolation‐by‐distance pattern. Multiple introductions and non‐directional gene flow are most likely promoted by anthropogenic disturbance and human‐mediated dispersal. Our results demonstrate the ability and speed of A. artemisiifolia to settle in newly disturbed areas and the difficulties to predict invasion directions, as downstream river dispersal was negligible.
Effects of yoga interventions practised in heated and thermoneutral conditions on endothelium‐dependent vasodilatation: The Bikram yoga heart study
Authors: Hunter Stacy D. , Laosiripisan Jitanan , Elmenshawy Ahmed , Tanaka Hirofumi
Published: January 2018

New Findings

What is the central question of this study?

Does the heated practice environment enhance the effects of Bikram yoga on endothelium‐dependent vasodilatation in healthy, middle‐aged adults?

What is the main finding and its importance?

The primary finding from this investigation is that the hatha yoga postures in the Bikram yoga series produce similar enhancements in endothelium‐dependent vasodilatation in healthy, middle‐aged adults regardless of environmental temperature. These findings highlight the efficacy of yoga postures in producing improvements in vascular health and downplay the necessity of the heated practice environment in inducing vascular adaptations.

We have previously documented improvements in endothelium‐dependent vasodilatation with a Bikram (hot) yoga intervention in middle‐aged adults. At present, the effect of environmental temperature in hot yoga on endothelial function is unknown. The purpose of this investigation was to determine the effects of Bikram yoga interventions performed in heated or thermoneutral conditions on endothelium‐dependent vasodilatation. Fifty‐two sedentary but apparently healthy adults aged 40–60 years were randomly assigned to one of three groups: Bikram yoga practised at 40.5°C (n = 19), Bikram yoga practised at 23°C (n = 14) or sedentary time control (n = 19). The yoga interventions consisted of 90 min Bikram yoga classes three times a week for 12 weeks. Endothelium‐dependent vasodilatation was measured non‐invasively using brachial artery flow‐mediated dilatation (FMD). Body fat percentage determined via dual‐energy X‐ray absorptiometry was significantly lower in the hot yoga group after the intervention than in the thermoneutral yoga and control conditions. Brachial artery FMD increased (P < 0.05) in the thermoneutral yoga group and tended to increase in the hot yoga group (P = 0.056). No changes occurred in the control group. There were no significant differences in FMD change scores between groups. We conclude that Bikram yoga practised in thermoneutral conditions improved endothelium‐dependent vasodilatation in healthy, middle‐aged adults. These new findings highlight the effectiveness of hatha yoga postures alone, in the absence of a heated practice environment, in improving vascular health and are of clinical significance given the increased propensity for heat intolerance in ageing adults.
Aortic dysfunction in metabolic syndrome mediated by perivascular adipose tissue TNFα‐ and NOX2‐dependent pathway
Authors: DeVallance Evan , Branyan Kayla W. , Lemaster Kent , Olfert I. Mark , Smith David M. , Pistilli Emidio E. , Frisbee Jefferson C. , Chantler Paul D.
Published: January 2018

New Findings

What is the central question of this study?

Tumour necrosis factor‐α (TNFα) has been shown to impair vascular function, but the impact of thoracic aorta perivascular adipose tissue (tPVAT)‐derived TNFα on tPVAT and aortic function in metabolic syndrome is unknown.

What is the main finding and its importance?

Release of TNFα by tPVAT causes production of reactive oxygen species in tPVAT through activation of an NADPH‐oxidase 2 (NOX2)‐dependent pathway, activates production of aortic reactive oxygen species and mediates aortic stiffness, potentially through matrix metalloproteinase 9 activity. Neutralization of TNFα and/or inhibition of NOX2 blocks the tPVAT‐induced impairment of aortic function. These data partly implicate tPVAT NOX2 and TNFα in mediating the vascular pathology of metabolic syndrome.

Perivascular adipose tissue (PVAT) is recognized for its vasoactive effects, but it is unclear how metabolic syndrome impacts thoracic aorta (t)PVAT and the subsequent effect on functional and structural aortic stiffness. Thoracic aorta and tPVAT were removed from 16‐ to 17‐week‐old lean (LZR, n = 16) and obese Zucker rats (OZR, n = 16). The OZR presented with aortic endothelial dysfunction, assessed by wire myography, and increased aortic stiffness, assessed by elastic modulus. The OZR tPVAT exudate further exacerbated the endothelial dysfunction, reducing nitric oxide and endothelium‐dependent relaxation (P < 0.05). Additionally, OZR tPVAT exudate had increased MMP9 activity (P < 0.05) and further increased the elastic modulus of the aorta after 72 h of co‐culture (P < 0.05). We found that the observed aortic dysfunction caused by OZR tPVAT was mediated through increased production and release of tumour necrosis factor‐α (TNFα; P < 0.01), which was dependent on tPVAT NADPH‐oxidase 2 (NOX2) activity. The OZR tPVAT release of reactive oxygen species and subsequent aortic dysfunction were inhibited by TNFα neutralization and/or inhibition of NOX2. Additionally, we found that OZR tPVAT had reduced activity of the active sites of the 20S proteasome (P < 0.05) and reduced superoxide dismutase activity (P < 0.01). In conclusion, metabolic syndrome causes tPVAT dysfunction through an interplay between TNFα and NOX2 that leads to tPVAT‐mediated aortic stiffness by activation of aortic reactive oxygen species and increased MMP9 activity.
Method and Validation for Measurement of Effective Thermal Diffusivity and Conductivity of Pebble Bed in High Temperature Gas-Cooled Reactors
Authors: Wu Yongyong , Ren Cheng , Li Rui , Yang Xingtuan , Tu Jiyuan , Jiang Shengyao
Published: January 2018

The effective thermal diffusivity and conductivity of pebble bed in the high temperature gas-cooled reactor (HTGR) are two vital parameters to determine the operating temperature and power in varisized reactors with the restriction of inherent safety. A high-temperature heat transfer test facility and its inverse method for processing experimental data are presented in this work. The effective thermal diffusivity as well as conductivity of pebble bed will be measured at temperature up to 1600 °C in the under-construction facility with the full-scale in radius. The inverse method gives a global optimal relationship between thermal diffusivity and temperature through those thermocouple values in the pebble bed facility, and the conductivity is obtained by conversion from diffusivity. Furthermore, the robustness and uncertainty analyses are also set forth here to illustrate the validity of the algorithm and the corresponding experiment. A brief experimental result of preliminary low-temperature test is also presented in this work.
Plane Contact and Adhesion of Two Elastic Solids With an Interface Groove
Authors: Jin Fan , Guo Xu , Wan Qiang
Published: January 2018

A systematic study is performed on the plane contact and adhesion of two elastic solids with an interface groove. The nonadhesion and Johnson–Kendall–Roberts (JKR) adhesion solutions for a typical groove shape are obtained in closed form by solving singular integral equations and using energy release rate approaches. It is found that the JKR adhesion solution depends solely on a dimensionless parameter α and the groove is predicted to be unstably flattened with no applied load when α≥0.535. Furthermore, the corresponding Maugis–Dugdale adhesion model has been revisited with three possible equilibrium states. By introducing the classical Tabor parameter μ, a complete transition between the nonadhesion and the JKR adhesion contact models is captured, which can be recovered as two limiting cases of the Maugis–Dugdale model. Depending on two nondimensional parameters α and μ, where α2 represents the ratio of the surface energy in the groove to the elastic strain energy when the grooved surface is flattened, different transition processes among three equilibrium states are characterized by one or more jumps between partial and full contact. Larger values of α and μ tend to induce more energy loss due to adhesion hysteresis. Combination values of α and μ are also suggested to design self-healing interface grooves due to adhesion.
Validation of a Numerical Model for Predicting Stalled Flows in a Low-Speed Fan—Part II: Unsteady Analysis
Authors: Lee Kuen-Bae , Dodds John , Wilson Mark , Vahdati Mehdi
Published: January 2018

This paper investigates the flow near the stall boundary for a low-speed/low-pressure ratio fan. Three-dimensional, Reynolds-averaged Navier–Stokes computations are performed for a modern low speed fan rig for which extensive measured data are available. Simulations are conducted at 80% corrected speed, for which the measured constant speed characteristic contains a part with positive slope. It is shown in this paper that by using an unsteady whole assembly approach, it is possible to predict the flow for all the points on the measured constant speed characteristic (including those on the positive slope part), which is not achievable by using a single passage strategy as it would result in premature “numerical stall.” The results of the computations reveal that for the operating points on the positive slope part of the characteristic, the flow structure becomes asymmetric and hence requires a whole assembly numerical model. The type of asymmetry which appears at lower flow coefficients is similar to the multicell, part span rotating stall, which can occur on the front stages of core compressors at stable operating conditions. The numerical results showed a good correlation with the measured data in terms of stall characteristics.
Measurements of Radial Vortices, Spill Forward, and Vortex Breakdown in a Transonic Compressor
Authors: Brandstetter Christoph , Jüngst Maximilian , Schiffer Heinz-Peter
Published: January 2018

The phenomena prior to rotating stall were investigated in a high-speed compressor test rig using optical and pneumatic measurement techniques. A number of throttling procedures were performed at transonic and subsonic speedlines with the aim to detect the unsteady effects initiating rotating stall or large amplitude blade vibrations. At transonic speed, radial vortices traveling around the circumference were detected in the upstream part of the rotor using phase-locked particle-image-velocimetry (PIV) measurements above 92% span and unsteady wall pressure measurements. When these radial vortices impinge on a blade leading edge (LE), they cause a forward spill of fluid around the LE. The effects are accompanied by a large-scale vortex breakdown in the blade passage leading to immense blockage in the endwall region. At subsonic speeds, the observed flow phenomena are similar but differ in intensity and structure. During the throttling procedure, blade vibration amplitudes were monitored using strain gauges (SG) and blade tip timing instrumentation. Nonsynchronous blade vibrations in the first torsional eigenmode were measured as the rotor approached stall. Using the different types of instrumentation, it was possible to align the aerodynamic flow features with blade vibration levels. The results show a clear correlation between the occurrence of radial vortices and blade vibrations.
Detailed Heat Transfer Measurements of Jet Impingement on Dimpled Target Surface Under Rotation
Authors: Singh Prashant , Ekkad Srinath V.
Published: January 2018

The present study investigates the effects of Coriolis force and centrifugal buoyancy force on heat transfer due to jet impingement on dimpled target surface (DT). Detailed heat transfer measurements were carried out using transient liquid crystal (LC) thermography, where the target surface was modeled as one-dimensional (1D) semi-infinite solid. Three different configurations of DT surfaces have been studied. The flow and rotation conditions have been kept the same for all the configurations, where the average Reynolds number (based on jet hole hydraulic diameter: Rej) was 2500 and the rotational speed was 400 rpm (corresponding to Roj of 0.00274). Under nonrotating conditions, DT surface showed positive heat transfer enhancements compared to smooth target surfaces. Under rotating conditions, it was observed that rotation was helpful in enhancing heat transfer on leading and trailing sides for smooth target surface. However, for the DT surfaces, rotation proved to be detrimental to heat transfer enhancement.
Planar Linkage Synthesis for Mixed Motion, Path, and Function Generation Using Poles and Rotation Angles1
Authors: Zimmerman Ronald A.
Published: January 2018

The kinematic synthesis of planar linkage mechanisms has traditionally been broken into the categories of motion, path, and function generation. Each of these categories of problems has been solved separately. Many problems in engineering practice require some combination of these problem types. For example, a problem requiring coupler points and/or poses in addition to specific input and/or output link angles that correspond to those positions. A limited amount of published work has addressed some specific underconstrained combinations of these problems. This paper presents a general graphical method for the synthesis of a four bar linkage to satisfy any combination of these exact synthesis problems that is not overconstrained. The approach is to consider the constraints imposed by the target positions on the linkage through the poles and rotation angles. These pole and rotation angle constraints (PRCs) are necessary and sufficient conditions to meet the target positions. After the constraints are made, free choices which may remain can be explored by simply dragging a fixed pivot, a moving pivot, or a pole in the plane. The designer can thus investigate the family of available solutions before making the selection of free choices to satisfy other criteria. The fully constrained combinations for a four bar linkage are given and sample problems are solved for several of them.
Deterministic Design for a Compliant Parallel Universal Joint With Constant Rotational Stiffness
Authors: Xie Yan , Yu Jingjun , Zhao Hongzhe
Published: January 2018

Compliant universal joints have been widely employed in high-precision fields due to plenty of good performance. However, the stiffness characteristics, as the most important consideration for compliant mechanisms, are rarely involved. In this paper, a deterministic design for a constraint-based compliant parallel universal joint with constant rotational stiffness is presented. First, a constant stiffness realization principle is proposed by combination of the freedom and constraint topology (FACT) method and beam constraint model (BCM) to establish a mapping relationship between stiffness characteristics and topology configurations. A parallel universal joint topology is generated by the constant stiffness realization principle. Then, the analytical stiffness model of the universal joint with some permissible approximations is formulated based on the BCM, and geometrical prerequisites are derived to achieve the desired constant rotational stiffness. After that, finite element analysis (FEA), experimental testing, and detailed stiffness analysis are carried out. It turns out that the rotational stiffness of the universal joint can keep constant with arbitrary azimuth angles even if the rotational angle reaches up to ±5 deg. Meanwhile, the acceptable relative errors of rotational stiffness are within 0.53% compared with the FEA results and 2.6% compared with the experimental results, which indicates the accuracy of the theoretical stiffness model and further implies the feasibility of constant stiffness realization principle on guiding the universal joint design.
Residual Stresses in Dissimilar Friction Stir Welding of AA2024 and AZ31: Experimental and Numerical Study
Authors: Hou Z. , Sheikh-Ahmad J. , Jarrar F. , Ozturk F.
Published: January 2018

Thermal history and residual stresses in dissimilar friction stir welding (FSW) of AA2024 and AZ31 were studied under different tool offsets using a coupled Eulerian–Lagrangian (CEL) finite element model and a mechanical model. Welding experiments and residual stresses' measurements were conducted to validate the models. Comparisons between the experimental and numerical results indicated good agreement. The maximum temperature in the welded zone was predicted to be slightly lower than 400 °C, regardless of offset, and that its location shifted with tool offset from the advancing side (AS) to the retreating side (RS). Longitudinal residual stresses changed from tensile under the tool shoulder to compressive beyond this region and it appeared to be the dominant stress component. The transverse stresses were tensile and of lower magnitude. Both the longitudinal and transverse residual stresses have their maximum values within the weld zone near the end of the weld length. For both peak temperatures and residual stresses, higher values were obtained at the AS with no tool offset and 1 mm offset to the AS, and at the RS with 1 mm offset to the RS. Lower residual stresses and better weld quality were obtained with tool offset to the aluminum side.
Antimicrobial Resistance in
Stenotrophomonas
spp
Authors: Wang Yang , He Tao , Shen Zhangqi , Wu Congming
Published: January 2018

Bacteria of the genus
Stenotrophomonas
are found throughout the environment, in close association with soil, sewage, and plants.
Stenotrophomonas maltophilia
, the first member of this genus, is the predominant species, observed in soil, water, plants, animals, and humans. It is also an opportunistic pathogen associated with the increased number of infections in both humans and animals in recent years. In this article, we summarize all
Stenotrophomonas
species (mainly
S. maltophilia
) isolated from animals and food products of animal origin and further distinguish all isolates based on antimicrobial susceptibility and resistance phenotypes. The various mechanisms of both intrinsic and acquired antimicrobial resistance, which were mainly identified in
S. maltophilia
isolates of nosocomial infections, have been classified as follows: multidrug efflux pumps; resistance to β-lactams, aminoglycosides, quinolones, trimethoprim-sulfamethoxazole, and phenicols; and alteration of lipopolysaccharide and two-component regulatory systems. The dissemination, coselection, and persistence of resistance determinants among
S. maltophilia
isolates have also been elaborated.
Toward Forensic Uses of Microbial Source Tracking
Authors: Teaf Christopher M. , Flores David , Garber Michele , Harwood Valerie J.
Published: January 2018

The science of microbial source tracking has allowed researchers and watershed managers to go beyond general indicators of fecal pollution in water such as coliforms and enterococci, and to move toward an understanding of specific contributors to water quality issues. The premise of microbial source tracking is that characteristics of microorganisms that are strongly associated with particular host species can be used to trace fecal pollution to particular animal species (including humans) or groups, e.g., ruminants or birds. Microbial source tracking methods are practiced largely in the realm of research, and none are approved for regulatory uses on a federal level. Their application in the conventional sense of forensics, i.e., to investigate a crime, has been limited, but as some of these methods become standardized and recognized in a regulatory context, they will doubtless play a larger role in applications such as total maximum daily load assessment, investigations of sewage spills, and contamination from agricultural practices.
P20 Stability study of a mixed system of sodium benzoate and sodium phenylbutyrate in intravenous (iv) infusion fluids
Authors: William Batten , Hannah Batechelor , Daniela Monti
Published: January 2018

Aim

A combination of sodium benzoate and sodium phenylbutyrate is used as intravenous therapy in hyperammonaemia at concentrations up to 50 mg/mL. Currently, concentrated solutions of each component are available. The preparation relies on the accurate measurement of each component in a syringe or bag which then mixes via a Y-site, immediately prior to administration. A ready mixed product would potentially confer improvements in safety and convenience. An improvement would be the availability of a pre-mixed product, which requires less manipulation prior to administration. The aim of this work was to evaluate the chemical stability of a mixed system of sodiumbenzoate and sodium phenylbutyrate in glucose 10%, with relevant packaging conditions both at room temperature and at accelerated- degradations temperatures, with exposure to ultra violet (UV) light. Successful demonstration of compatibility across a range of conditions may provide impetus for the manufacture of pre-mixed intravenous therapy. This would improve efficiency of intravenous drug preparation and administration with the associated patient safety benefits of more accurate drug concentrations.

Method

The chemical stability of sodium benzoate and sodium phenylbutyrate was monitored by measuring concentrations using high-performance liquid chromatography. The stability of the mixed system was evaluated at a range of concentrations(20 mg/mL, 25 mg/mL, 30 mg/mL, 40 mg/mL and 50 mg/mL) of both components in solutions of 10% w/v glucose in deionised water stored at three temperatures; refrigerated (4°C–8°C), at room temperature (20°C–25°C), and at 37°C. Glass and plastic were compared as packaging materials both with and without exposure to UV light. All mixed solutions were stored for up to 12 weeks.

Results

Drug content remained above 98% for all mixed systems at all conditions for 12 weeks.

Conclusion

Combination mixed systems of sodium benzoate and sodium phenylbutyrate were found to be stable for up to 12 weeks when stored in glass or plastic containers, exposure to high temperatures and UV light did not significantly affect the concentration of the drug present. This stability data will allow institutions to prepare pre-mixed solutions in advance for sodium benzoate and sodium phenylbutyrate in 10% glucose.It has patient safety benefits as it provides support of current clinical practice of the IV drug compatibility of sodium benzoate and sodium phenylbutyrate. It also provides quantitative reassurance in larger patients where current practice is to add the two drugs to a single bag for infusion. Moreover, it may also pave the way for commercial manufactured solutions of sodium benzoate and sodium phenylbutyrate to be produced. In practice, l-arginine is given via a Y-site alongside the two components,and work is currently underway repeating the study with all three components to assess compatibility.