bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative effects of valsartan plus cilnidipine or hydrochlorothiazide on nocturnal home blood pressure
Authors: Fujiwara Takeshi , Hoshide Satoshi , Tomitani Naoko , Kanegae Hiroshi , Kario Kazuomi
Published: January 2021

We tested our hypothesis that, in hypertensive patients with higher nocturnal home systolic blood pressure (HSBP) at baseline, a valsartan/cilnidipine (80/10 mg) combination would reduce nocturnal HSBP more markedly than a valsartan/hydrochlorothiazide (80/12.5 mg) combination. Patients measured their nocturnal HSBP over three nights prior to study randomization and at the end of treatment. Sixty‐three and 66 patients comprised the valsartan/cilnidipine and valsartan/hydrochlorothiazide groups; their respective baseline nocturnal HSBP values were 124.3 ± 15.6 and 125.8 ± 15.2 mm Hg (P = .597). Nocturnal HSBPs were significantly reduced from baseline in both groups. Although the valsartan/hydrochlorothiazide group exhibited a significantly greater reduction in nocturnal HSBP compared to the valsartan/cilnidipine group (−5.0 vs. −10.0 mm Hg, P = .035), interaction between the treatment groups and the baseline nocturnal HSBP levels for the changes in nocturnal HSBP after the treatment periods was significant (P = .047). The BP‐lowering effect of valsartan/cilnidipine was more dependent on baseline nocturnal HSBP than that of valsartan/hydrochlorothiazide.
Human antigen R regulates hypoxia‐induced mitophagy in renal tubular cells through PARKIN/BNIP3L expressions
Authors: Yu Shao‐Hua , Palanisamy Kalaiselvi , Sun Kuo‐Ting , Li Xin , Wang Yao‐Ming , Lin Feng‐Yen , Chen Kuen‐Bao , Wang I‐Kuan , Yu Tung‐Min , Li Chi‐Yuan
Published: January 2021

Mitochondrial dysfunction contributes to the pathophysiology of acute kidney injury (AKI). Mitophagy selectively degrades damaged mitochondria and thereby regulates cellular homeostasis. RNA‐binding proteins (RBPs) regulate RNA processing at multiple levels and thereby control cellular function. In this study, we aimed to understand the role of human antigen R (HuR) in hypoxia‐induced mitophagy process in the renal tubular cells. Mitophagy marker expressions (PARKIN, p‐PARKIN, PINK1, BNIP3L, BNIP3, LC3) were determined by western blot analysis. Immunofluorescence studies were performed to analyze mitophagosome, mitolysosome, co‐localization of p‐PARKIN/TOMM20 and BNIP3L/TOMM20. HuR‐mediated regulation of PARKIN/BNIP3L expressions was determined by RNA‐immunoprecipitation analysis and RNA stability experiments. Hypoxia induced mitochondrial dysfunction by increased ROS, decline in membrane potential and activated mitophagy through up‐regulated PARKIN, PINK1, BNIP3 and BNIP3L expressions. HuR knockdown studies revealed that HuR regulates hypoxia‐induced mitophagosome and mitolysosome formation. HuR was significantly bound to PARKIN and BNIP3L mRNA under hypoxia and thereby up‐regulated their expressions through mRNA stability. Altogether, our data highlight the importance of HuR in mitophagy regulation through up‐regulating PARKIN/BNIP3L expressions in renal tubular cells.
Role of melatonin in the dynamics of acute spinal cord injury in rats
Authors: Bi Jiaqi , Shen Jianxiong , Chen Chong , Li Zheng , Tan Haining , Sun Peiyu , Lin Youxi
Published: January 2021

Melatonin is well‐documented to have the ability of reducing nerve inflammation and scavenging free radicals. However, the therapeutic effect of melatonin on spinal cord injury has not been fully described. In this study, we assessed the effect of melatonin on T9 spinal cord injury established by Allen method in rats. Melatonin deficiency significantly delayed the recovery of sensory and motor functions in SCI rats. Treatment with melatonin significantly alleviated neuronal apoptosis and accelerated the recovery of spinal cord function. These results suggest that melatonin is effective to ameliorate spinal cord injury through inhibition of neuronal apoptosis and promotion of neuronal repair.
Causal Effect of Tooth Loss on Functional Capacity in Older Adults in England: A Natural Experiment
Authors: Matsuyama Yusuke , Listl Stefan , Jürges Hendrik , Watt Richard G. , Aida Jun , Tsakos Georgios
Published: January 2021

Background/Objectives

Tooth loss is associated with reduced functional capacity, but so far, there is no relevant causal evidence reported. We investigated the causal effect of tooth loss on the instrumental activities of daily living (IADL) among older adults in England.

Design

Natural experiment study with instrumental variable analysis.

Setting

The English Longitudinal Study of Aging (ELSA) combined with the participants' childhood exposure to water fluoride due to the community water fluoridation.

Participants

Five thousand six hundred and thirty one adults in England born in 1945–1965 participated in the ELSA wave seven survey (conducted in 2014–2015; average age: 61.0 years, 44.6% men).

Measurements

The number of natural teeth predicted by the exogenous geographical and historical variation in exposure to water fluoride from age 5 to 20 years old (instrumental variable) was used as an exposure variable. The outcome, having any limitations in IADL (preparing a hot meal, shopping for groceries, making telephone calls, taking medications, doing work around the house or garden, or managing money), was assessed by self‐reported questionnaires.

Results

Linear probability model with Two‐Stage Least Squares estimation was fitted. Being exposed to fluoridated water was associated with having more natural teeth in later life (coefficient: 0.726; 95% confidence interval (CI) = 0.311, 1.142; F = 11.749). Retaining one more natural tooth reduced the probability of having a limitation in IADL by 3.1 percentage points (coefficient: −0.031; 95% CI = −0.060, −0.002).

Conclusion

Preventing tooth loss maintains functional capacity among older adults in England. Given the high prevalence of tooth loss, this effect is considerable. Further research on the mechanism of the observed causal relationship is needed.
Potassium reduction in food by preparation technique for the dietetic management of patients with chronic kidney disease: a review
Authors: Batista R. Aparecida Borges , Japur C. Cremonezi , Prestes I. Valente , Fortunato Silva J. , Cavanha M. , das Graças Pena G.
Published: January 2021

Background

Chronic kidney disease patients often use food preparation techniques to reduce potassium intake. However, the most effective techniques have not yet been determined for all food groups. The present study aimed to analyse all of the available information on potassium reduction in the food and identify the best preparation techniques by comparing the trend of change in potassium level.

Methods

Nine databases were searched from 1976 to May 2020, according to the PRISMA Statement. We included all articles reporting the amount of potassium before and after the application of food preparation techniques. Data were analysed using the Wilcoxon test and statistical simulation.

Results

A wide variety of food and culinary processes was observed in the 65 included articles. Cooking in water, pressure cooking and cooking in a microwave oven reduced potassium levels in all food groups, particularly in cereals and derivatives, fruits and derivatives, meats and derivatives, legumes, and leafy and cruciferous vegetables. Soaking food significantly reduced the potassium content in tubers and roots and leafy and cruciferous vegetables. Steam cooking and dry heating cooking also reduced potassium, although at a level lower than the other techniques.

Conclusions

The present review shows that, in general, all food preparation techniques can reduce the potassium content, although cooking in water and soaking promotes a greater reduction; however, more studies with standardised techniques and complete data are necessary.
Morphological changes in the experimental model of polycystic ovary syndrome and effects of vitamin D treatment
Authors: Azhar Arfa , Haider Ghulam , Naseem Zehra , Farooqui Nida , Farooqui Mohammad U. , Rehman Rehana
Published: January 2021

Aim

This research was designed to develop an animal model by inducing polycystic ovary syndrome (PCOS) with dehydroepiandrosterone (DHEA) and observe reproductive and morphological changes after treatment with vitamin D.

Materials and Methods

Thirty pre‐pubertal female Sprague–Dawley (SD) dams were recruited. The animals were distributed 10 each in control, PCOS and vitamin D‐treated groups. In control group 0.2 ml of sesame oil was given. PCOS group was administered DHEA by the daily dose of 6 mg/kg for 30 days. In vitamin D‐treated group, animals were injected 6 mg/kg/day DHEA daily and 120 ng 1, 25(OH) 2D3/100 g subcutaneously once a week. The occurrence of reproductive phenotypic PCOS was evaluated by estrous cycle, morphology and histological changes of ovary, uterus on light microscope.

Results

The results of this study showed significant weight gain, obesity, and estrous irregularity in PCOs group as compared to control and vitamin D‐treated group.

Conclusion

Administration of vitamin D (120 ng 1, 25(OH) 2D3/100) improved the cycle characteristics, reduced body weight and morphological features in PCOS induced animals. The results support the effect of vitamin D treatment for metabolic and reproductive characteristic features in PCOS females.
Cord blood gas results of pregnancies complicated by preeclampsia and the relationship of these results with the amount of proteinuria
Authors: Demir Ömer , Sal Hidayet , Ozalp Mirac , Aran Turhan , Osmanağaoğlu Mehmet A.
Published: January 2021

Aim

To evaluate whether there is a statistically significant difference between the cord blood gas parameters of pregnancies complicated with preeclampsia and uncomplicated pregnancies and to show whether the amount of proteinuria affects fetal cord blood gas parameters in pregnancies complicated with preeclampsia.

Methods

The study was designed retrospectively. Between 2016 and 2019, the neonatal results and cord blood gas results of 109 pregnant women who were diagnosed with preeclampsia and 75 nonpreeclamptic randomly selected pregnant women were compared. The preeclampsia group was divided into groups according to amount of proteinuria. SPSS 21.0 statistics program was used, and comparative analysis was carried out.

Results

The data of the 109 preeclampsia cases and 75 control groups included in the study were compared, and there was no statistical difference between the fetal cord blood gas parameters between the groups (p > 0.05). The median first and fifth minute Apgar scores were found significantly lower in the preeclampsia group compared to the control group (6, 8 and 8, 9, respectively;p < 0.001). Also, the amount of proteinuria does not alter cord blood gas parameters (p > 0.05).

Conclusion

Preeclampsia poses a risk for the neonatal period as it reduces the neonatal Apgar scores due to the chronic hypoxic process it creates. However, it was observed that the amount of proteinuria, which is one of the diagnostic criteria, did not affect neonatal results on Apgar scores or fetal cord blood gas parameters.
Diagnostic accuracy of a lung ultrasound protocol (Vet BLUE) for detection of pleural fluid, pneumothorax and lung pathology in dogs and cats
Authors: Cole L. , Pivetta M. , Humm K.
Published: January 2021

Objectives

To assess the accuracy of the lung ultrasound protocol Vet BLUE, using thoracic CT as the reference standard, for the detection of thoracic pathology in dogs and cats.

Materials and Methods

Animals that had thoracic ultrasound and thoracic CT were prospectively recruited between May 2017 and September 2018. The Vet BLUE protocol was performed on animals at the time of admission by veterinarians with basic training in emergency ultrasound. A board‐certified radiologist, blinded to the Vet BLUE findings, reviewed the CT images.

Results

CT was abnormal in 64.5% (20/31) animals. The number of CT sites positive for alveolar‐interstitial syndrome was 24.2% (60/248). When using CT as the reference standard, detection of ≥3 B lines with thoracic ultrasound had a sensitivity of 18.33% and specificity of 98.4% for detection of site specific alveolar‐interstitial syndrome. The sensitivity of Vet BLUE to detect alveolar‐interstitial syndrome increased to 56.9% when including the presence of any B line as abnormal. Overall accuracy for detection of alveolar‐interstitial syndrome based on these two criteria was 79% and 73%, respectively. Vet BLUE correctly identified consolidation in 58.3% (14/24) sites, pleural effusion in 66.6% (2/3) cases, pneumothorax in 33.3% (1/3) cases and intrathoracic mass in 25% (1/4) cases.

Clinical Significance

The Vet BLUE protocol is a useful technique to detect alveolar‐interstitial syndrome and other thoracic pathology but should not be used as a sole imaging method. Detection of ≥3 B lines is highly suggestive of alveolar‐interstitial syndrome and warrants further diagnostics.
Temporal Strategies: Governments Alter the Pace of Legislation in Bicameralism Depending on Electoral Expectations
Authors: Garwe Christoph , Engst Benjamin G. , Stawicki Yannick G. , Hönnige Christoph
Published: January 2021

Does a government in a bicameral system strategically alter the length of the legislative process in the first chamber in anticipation of future majorities in the second chamber? Drawing on an existing formal model of dynamic policymaking, we argue that governing majorities strategically accelerate or delay their agenda when a potential majority change in the second chamber is imminent. If the government fears losing control over the second chamber, then the government accelerates their agenda. By contrast, if the government hopes to gain control over the second chamber, the government decelerates their agenda. We test our argument in Germany's symmetric and asymmetric bicameralism by analyzing 1,966 governmental bills from 1998 to 2013. The analyses confirm our expectations for symmetric bicameralism, thus suggesting that the synchronicity of election cycles should be taken into account both in the analysis of bicameral systems and in institutional design of such systems.
Mental health workers' experiences of support and help‐seeking following workplace violence: A qualitative study
Authors: Rodrigues Nicole C. , Ham Elke , Kirsh Bonnie , Seto Michael C. , Hilton N. Zoe
Published: January 2021

The consequences of workplace trauma among mental health staff can include physical injuries and somatic disorders, professional exhaustion and burnout, depression, anxiety, and other occupational stress injuries. For the well‐being of staff and patients, there is a need to understand mental health workers' experiences following exposure to workplace trauma, any subsequent mental health problems, and the process of help‐seeking. The nuances of these experiences can best be captured through qualitative exploration. In this study, we explored inpatient mental health workers' experiences of support and help‐seeking following workplace violence. Four overall themes emerged from interviews with 12 participants: (i) validation as motivation for help‐seeking; (ii) stigma as a barrier to help‐seeking; (iii) gaps in services provided; and (iv) desire for accessible and effective trauma support and education. This study demonstrates the need for supportive management responses and peer support, access to specialized and confidential trauma‐informed mental health services, and reductions in stigma, victim blaming, and other barriers to help‐seeking among mental health workers.
Thiamine fortification strategies in low‐ and middle‐income settings: a review
Authors: Whitfield Kyly C. , Smith Taryn J. , Rohner Fabian , Wieringa Frank T. , Green Tim J.
Published: January 2021

Thiamine (vitamin B1) is an essential micronutrient in energy metabolism and cognitive and neurological health. Thiamine deficiency disorders (TDDs) have a range of clinical presentations that result in various morbidities and can be fatal if not promptly recognized and treated, especially in infants. To intervene, thiamine intakes by breastfeeding mothers and others at risk of thiamine deficiency should be increased to ensure adequate thiamine intake. Although thiamine fortification programs have a long history in high‐income countries, there are few mandatory fortification programs to address TDDs in low‐ and middle‐income countries (LMICs), particularly in the regions of greatest concern, South and Southeast Asia. This review highlights essential aspects for consideration in the development of a mandatory fortification program in LMICs, including an overview of the data required to model fortification dosing schemes, available thiamine fortificants, and potential fortification vehicles, as well as identifies current knowledge gaps.
Ancel Keys: The legacy of a giant in physiology, nutrition, and public health
Authors: Montani Jean‐Pierre
Published: January 2021

Ancel Keys, whose life spanned over 100 years (1904–2004), made a wealth of seminal scientific and public health contributions. As a physiologist, nutritionist, and public health scientist, he has left his mark on the 20th century by exploring different areas of physiology and nutrition, as well as by contributing to the understanding of basic public health issues. Among his major achievements one can mention in chronological order: studying adaptation to very high altitude, developing the K ration to enable the US military to survive with light but dense food, dissecting the physiology of starvation and nutritional rehabilitation to optimize recovery of functions, uncovering the link between serum cholesterol and heart disease, coordinating the first multi‐country epidemiological longitudinal study in nutrition and health, coining the word “body mass index” (BMI), which he showed to be the best body weight index to predict body fat, and promoting the Mediterranean diet for a healthy life style. This review examines the historical events and scientific intrigues that have surrounded Ancel Keys's major classical studies that have ensured him a central place in the history of medical science.
More stories to tell: NONEXPRESSOR OF PATHOGENESIS‐RELATED GENES1, a salicylic acid receptor
Authors: Chen Jian , Zhang Jingyi , Kong Mengmeng , Freeman Andrew , Chen Huan , Liu Fengquan
Published: January 2021

Salicylic acid (SA) plays pivotal role in plant defense against biotrophic and hemibiotrophic pathogens. Tremendous progress has been made in the field of SA biosynthesis and SA signaling pathways over the past three decades. Among the key immune players in SA signaling pathway, NONEXPRESSOR OF PATHOGENESIS‐RELATED GENES1 (NPR1) functions as a master regulator of SA‐mediated plant defense. The function of NPR1 as an SA receptor has been controversial; however, after years of arguments among several laboratories, NPR1 has finally been proven as one of the SA receptors. The function of NPR1 is strictly regulated via post‐translational modifications and transcriptional regulation that were recently found. More recent advances in NPR1 biology, including novel functions of NPR1 and the structure of SA receptor proteins, have brought this field forward immensely. Therefore, based on these recent discoveries, this review acts to provide a full picture of how NPR1 functions in plant immunity and how NPR1 gene and NPR1 protein are regulated at multiple levels. Finally, we also discuss potential challenges in future studies of SA signaling pathway.
High‐resolution phenotyping of sorghum genotypic and phenotypic responses to low nitrogen and synthetic microbial communities
Authors: Chai Yen Ning , Ge Yufeng , Stoerger Vincent , Schachtman Daniel P.
Published: January 2021

Much effort has been placed on developing microbial inoculants to replace or supplement fertilizers to improve crop productivity and environmental sustainability. However, many studies ignore the dynamics of plant‐microbe interactions and the genotypic specificity of the host plant on the outcome of microbial inoculation. Thus, it is important to study temporal plant responses to inoculation in multiple genotypes within a single species. With the implementation of high‐throughput phenotyping, the dynamics of biomass and nitrogen (N) accumulation of four sorghum genotypes with contrasting N‐use efficiency were monitored upon the inoculation with synthetic microbial communities (SynComs) under high and low‐N. Five SynComs comprising bacteria isolated from field grown sorghum were designed based on the overall phylar composition of bacteria and the enriched host compartment determined from a field‐based culture independent study of the sorghum microbiome. We demonstrated that the growth response of sorghum to SynCom inoculation is genotype‐specific and dependent on plant N status. The sorghum genotypes that were N‐use inefficient were more susceptible to the colonization from a diverse set of inoculated bacteria as compared to the N‐use efficient lines especially under low‐N. By integrating high‐throughput phenotyping with sequencing data, our findings highlight the roles of host genotype and plant nutritional status in determining colonization by bacterial synthetic communities.
Germicidal UV Sources and Systems†
Authors: Bergman Rolf S.
Published: January 2021

The COVID‐19 pandemic has generated great interest in reviving an old intervention technology, particularly for air disinfection—ultraviolet germicidal irradiation (UVGI). Since UVGI was developed and refined more than 80–90 years ago, the ultraviolet source of choice has been almost exclusively the low‐pressure mercury vapor discharge lamp. Today, with new lamp technologies, there has been significant interest in the application of ultraviolet light‐emitting diodes and excimer lamps that emit in the UV‐C (180–280 nm) spectral band. This paper reviews these competing technologies with the aim of giving a sound basis for decisions on how to choose and install UV systems for disinfection of air and surfaces given the COVID‐19 pandemic.
Photosynthesis, fluorescence, and biomass responses of white oak seedlings to urban soil and air temperature effects
Authors: Sonti Nancy Falxa , Griffin Kevin L. , Hallett Richard A. , Sullivan Joe H.
Published: January 2021

Urban forest patches can provide critical ecosystem services and their ability to regenerate native tree species is critical to their sustainability. Little is known about native tree seedling establishment and physiological function in urban ecosystems. This growth chamber study examined the effects of urban soil and air temperatures on white oak (Quercus alba L.) germination, seedling growth, and leaf‐level physiology. A split‐plot design tested effects of field collected soils from urban and reference forest sites in Baltimore, Maryland, and warm (urban) versus cool (rural) growth chamber temperature regimes. Seedlings were harvested at the end of the 23‐week experiment to assess foliar chemistry and biomass allocation. Seed germination was unaffected by treatments and was high in both soil types and temperature regimes. Urban soils supported significantly higher total seedling biomass and had a significant effect on leaf‐level physiological parameters, with seedlings grown in urban soils having greater Anet, Vcmax, ETRmax, Jmax, PNUE, gs, Anet/Rd, and PIabs (an integrated chlorophyll fluorescence parameter). PIabs measurements taken throughout the experiment revealed a significant time × temperature interaction effect. Baltimore urban forest patch soils were higher in nutrients than reference soils, but also higher in heavy metals. Despite higher levels of heavy metals, these results demonstrate that urban forest patch soils are able to support robust white oak seedling growth and enhanced seedling physiological parameters. However, interactions with temperature suggest that warming air temperatures may cause seedling stress and reduced growth.
Evolution and biogeography of acidocerine water scavenger beetles (Coleoptera: Hydrophilidae) shaped by Gondwanan vicariance and Cenozoic isolation of South America
Authors: Short Andrew Edward Z. , Girón Jennifer C. , Toussaint Emmanuel F. A.
Published: January 2021

The water scavenger beetle subfamily Acidocerinae is a cosmopolitan, ecologically diverse lineage with more than 500 described species whose morphology and classification are poorly understood. We present the first phylogenetic analyses of the subfamily inferred from five loci (18S, 28S, H3, CAD, COI). We used secondary calibrations to estimate divergence times and employ this phylogeny to revise the classification and examine the historical biogeography of this lineage. Most genera are resolved as reciprocally monophyletic, with several exceptions:Horelophopsissyn. n.is recovered as a derived lineage of and placed in synonymy withAgraphydrus. The large genusHelochares, as well as its primary constituent subgeneraHelochares(s. str.) andHydrobaticusare found to be polyphyletic.Batocharesstat. n.andSindolusstat. rev.are elevated from subgenera ofHelocharesto generic rank.Crephelocharesstat. rev.is removed from synonymy withChasmogenus. We found that the crown Acidocerinae date to the mid‐Jurassic in South America + Africa (West Gondwana). South America and Africa remain important areas of endemism throughout the evolution of the lineage and are resolved either individually or in combination as the ancestral area for all but one clade that is older than 90 million years ago. Six of the seven lineages occurring in South America diverged more than 100 million years ago and are endemic to the region, suggesting the Neotropical acidocerine fauna became isolated following the breakup of West Gondwana. Conversely, lineages found on other Gondwanan fragments (India, Madagascar, Australia) are comparatively young and derived, with all being Cenozoic in age. The few taxa that occur in North America today are all the result of recent Cenozoic dispersal from South America, although North America may have played an important role as an ancestral area in the Mesozoic.
Experiencias del entorno deportivo de origen al asesorar a esgrimistas migrantes
Authors: Prato Luana , Alcaraz Saül , Ramis Yago , Torregrossa Miquel
Published: January 2021

Objetivo. Explorar las experiencias de entrenadores y profesionales de la salud, al asesorar la transición cultural y la carrera deportiva de esgrimistas colombianos migrantes. Método. Se conformaron dos grupos focales en los que participaron nueve personas (seis hombres y tres mujeres), de unequipo multidisciplinario de alto rendimiento en esgrima: cinco entrenadores y cuatro profesionales de la salud. Los datos se analizaron por medio del análisis temático reflexivo. Resultados. Se evidencia que acompañar la transición cultural de esgrimistas migrantesimpacta en el bienestar y las dinámicas de asesoramiento de entrenadores y profesionales de la salud. Se generaron dos temas centrales: (a) en guardia y (b) marchar y romper. En el primero comentaron haber experimentado sorpresa, dilemas y la sensación de pasar a un segundo plano respecto a su rol como asesores técnicos y de la salud. En el segundo, se evidenció el cambio en las dinámicas de asesoramiento (comunicación virtual) y el carácter reactivo de las relaciones a distancia. Conclusión. La migración en el deporte genera nuevos desafíos para el equipo multidisciplinario que acompaña y asesora a los deportistas, tanto mujeres como hombres. Se proponen recomendaciones prácticas para entrenadores y profesionales de la salud, basadas en la praxis cultural de la Psicología Cultural aplicada al deporte.
Research on Light-Weighting Mechanism of Pressure Strengthening for Austenitic Stainless Steels Cryogenic Vessels
Authors: Lu Qunjie , Zheng Jinyang , Huang Gai , Wu Yingzhe , Ding Huiming , Wang Yibo
Published: January 2021

Pressure strengthening (PS) technology, also called cold stretching, is widely used to increase the allowable stress and reduce the weight of cryogenic pressure vessels (CPVs) made of austenitic stainless steels (ASSs). However, with taking accounts of the manufacturing process and service environment of CPVs, the main source of the strengthening effect for yielding strength improvement is still unclarified. Therefore, in this work, the effect of the 9% prestrain and low-temperature (−196 °C) on cryogenic mechanical properties of S30408 stainless steel was comparatively investigated by cryogenic tensile test and martensitic transformation measurement. After evaluating the main source of strengthening increments, the effect of prestraining on welded joints was studied by Vickers microhardness test. Then the engineering significance of performing the PS on a cryogenic inner vessel was explored based on finite element analysis (FEA). It revealed that at −196 °C, the strengthening effect of low-temperature plays a leading role for strength increments, though the yield strength can be increased obviously by prestraining at room temperatures. Meanwhile, the performing of 9% prestrain could enhance the distribution uniformity of the Vickers microhardness of welded joints. Furthermore, the prior operation of PS on inner vessels is beneficial to prevent further plastic deformation during the subsequent hydraulic test, avoid thermal insulation degradation of the vacuum jackets and even stress concentrations in roots of pipes, which is also of engineering significance to smooth the subsequent processes such as the assembly with outer containers and other product tests.
Laminar Flame Speed Measurements of Kerosene-Based Fuels Accounting for Uncertainties in Mixture Average Molecular Weight
Authors: Keesee Charles L. , Guo Bing , Petersen Eric L.
Published: January 2021

New laminar flame speed experiments have been collected for some kerosene-based liquid fuels: Jet-A, RP-1, and diesel fuel #2. Accurately understanding the combustion characteristics of these, and all kerosene-based fuels in general, is an important step in developing new chemical kinetics mechanisms that can be applied to these fuels. It is well known that the precise composition of these fuels changes from one production batch to the next, leading to significant uncertainty in the mixture average properties. For example, uncertainty in a fuel blend's molecular weight can have a noticeable effect on defining an equivalence ratio for a typical fuel–air mixture, of the order of 15%. Because of these uncertainties, fuel mole fraction, XFUEL, is shown to be a more appropriate parameter for comparison between different batches of fuel. Additionally, a strong linear correlation was detected between the burned-gas Markstein length and the equivalence ratio. This correlation is shown to be useful in determining the acceptability and accuracy of individual data points. Spherically expanding flames were measured over a range of fuel mole fractions corresponding to equivalence ratios of φ = 0.7 to φ = 1.5, at initial conditions of 1 atm and 403 K in the high-temperature, high-pressure (HTHP) constant volume vessel at Texas A&M University. These new results are compared with the limited set of laminar flame speed data currently available in the literature for this fuel.
Prediction of Rotor Burst Using Strain-Based Fracture Criteria to Comply With the Engine Airworthiness Regulation
Authors: Li Huihui , Wang Kaiming , Zhang Chuncheng , Wang Weiguo , Chen Guoguang
Published: January 2021

Relative to the rotor overspeed compliance governed by civil aviation airworthiness regulation, nowadays the Area-Average Stress method is commonly used approach. However, in order to effectively apply the Area-Average Stress method in analyzing burst speed, large amount of testing data is needed to define an important element of this method: a correction factor. This prerequisite hinders the use of this method for many companies that have limited test data. Meanwhile, analysis of rotor burst speed based on Strain-based Fracture Criteria using true stress–strain curves and burst tests has been done on the low-pressure turbine (LPT) rotor, and a work procedure obtaining the most critical burst speed for certification is proposed. The analysis results, which had a good correlation with test results, showed that Strain-based Fracture Criteria can accurately predict the burst speed considering the most adverse combination of dimensional tolerances, temperature, and material properties, and rotor dimensional growth under the overspeed condition. Both are required by the aircraft engine airworthiness overspeed regulation. Compared to the Area-Average Stress method, Strain-based Fracture Criteria reflects the physical essence of the rotor burst more realistically and can be simply verified without requiring too much test data, therefore it has a good application prospect in the aircraft engine airworthiness.
Design, Development, and Temporal Evaluation of a Magnetic Resonance Imaging-Compatible In Vitro Circulation Model Using a Compliant Abdominal Aortic Aneurysm Phantom
Authors: Thirugnanasambandam Mirunalini , Canchi Tejas , Piskin Senol , Karmonik Christof , Kung Ethan , Menon Prahlad G. , Avril Stephane , Finol Ender A.
Published: January 2021

Biomechanical characterization of abdominal aortic aneurysms (AAAs) has become commonplace in rupture risk assessment studies. However, its translation to the clinic has been greatly limited due to the complexity associated with its tools and their implementation. The unattainability of patient-specific tissue properties leads to the use of generalized population-averaged material models in finite element analyses, which adds a degree of uncertainty to the wall mechanics quantification. In addition, computational fluid dynamics modeling of AAA typically lacks the patient-specific inflow and outflow boundary conditions that should be obtained by nonstandard of care clinical imaging. An alternative approach for analyzing AAA flow and sac volume changes is to conduct in vitro experiments in a controlled laboratory environment. In this study, we designed, built, and characterized quantitatively a benchtop flow loop using a deformable AAA silicone phantom representative of a patient-specific geometry. The impedance modules, which are essential components of the flow loop, were fine-tuned to ensure typical intraluminal pressure conditions within the AAA sac. The phantom was imaged with a magnetic resonance imaging (MRI) scanner to acquire time-resolved images of the moving wall and the velocity field inside the sac. Temporal AAA sac volume changes lead to a corresponding variation in compliance throughout the cardiac cycle. The primary outcome of this work was the design optimization of the impedance elements, the quantitative characterization of the resistive and capacitive attributes of a compliant AAA phantom, and the exemplary use of MRI for flow visualization and quantification of the deformed AAA geometry.
Aerodynamics of Boundary Layer Ingesting Fuselage Fans
Authors: Castillo Pardo Alejandro , Hall Cesare A.
Published: January 2021

Boundary layer ingestion (BLI) potentially offers significant reductions in fuel burn and pollutant emissions. The propulsive fuselage concept features a fan at the back of the airframe that ingests the 360 deg fuselage boundary layer. Consequently, the distortion at the fan face during cruise is close to radial. This article aims to devise and test a fan design philosophy that is tuned to this inflow distortion. Initially, a free-vortex fan design matched to clean inflow is presented. The effects of BLI on the aerodynamics of this fan are investigated. A series of design steps are then presented to develop the baseline fan into a new design matched to fuselage BLI inflow. Both fan designs have been tested within a low-speed rig. The impact of the fan design changes on the aerodynamics and the performance with BLI are evaluated using the test results. This article presents the successful application of a unique experimental facility for the analysis of BLI fuselage fans. It shows that it is possible to design a fan that accepts the radial distortion caused by fuselage BLI with a modified profile of work input. The new fan design was found to increase the work input by 4.9% and to improve the efficiency by 2.75% relative to a fan designed for clean flow. This new fan design has reduced loading near the hub to account for the incoming distortion and increased mid span loading and negative incidence toward the tip for tolerance to circumferential distortion off-design.
Investigation of Rapid, Moderate Temperature Change Thermal Cycles of a Micro-Tubular Flame-Assisted Fuel Cell
Authors: Milcarek Ryan J. , Garrett Michael J. , Welles Thomas S. , Ghotkar Rhushikesh , Ahn Jeongmin
Published: January 2021

Despite many efforts and improvements over the last few decades, two of the major challenges facing solid oxide fuel cells (SOFCs) are slow heating rates to operating temperature (typically < 5 °C · min−1) and a limited ability to thermal cycle (<200 cycles). Recently, a novel hybrid setup that combines a fuel-rich combustion reformer with a SOFC was developed and utilized to investigate rapid heating, cooling, and thermal cycling of a micro-tubular SOFC. In this work, 3000 moderate thermal cycles are conducted at a heating rate exceeding 140 °C · min−1 and a cooling rate that exceeded 100 °C · min−1. The open-circuit voltage (OCV) was analyzed over the 150 h test, and a low degradation rate of ∼0.0008 V per 100 cycles per fuel cell was observed in the absence of the current collector degradation. Unlike a previous test, which was conducted at lower temperatures, significant degradation of the current collector was observed during this test. Electrochemical impedance spectroscopy shows that degradation in the SOFC was due to increases in ohmic losses, activation losses at the cathode, and increased concentration losses.
Ammonia Borane and Its Applications in the Advanced Energy Technology
Authors: Li Haojie , Yan Yunfei , Feng Shuai , Chen Yanrong , Fan Hu
Published: January 2021

Ammonia borane (AB) is deemed to be the most promising energy storage material with varieties of exceptional properties, most reports mainly discuss its application in hydrogen storage and release as the hydrogen storage materials, which intends to address the hydrogen storage issues of on-board hydrogen fuel cell. However, some other promising applications of AB have also been confirmed by researchers, although these applications have not been intensively studied like its application of hydrogen storage materials. The article mainly introduce the synthesis, dehydrogenation (themolysis, hydrolysis, and methanolysis), and regeneration of AB and highlight the applications in green propulsion system of rocket, portable hydrogen source for on-board fuel cell, chemical catalysis, and electrochemical energy systems. In the meantime, the main achievements, current developments, limitations, and challenges in AB for advanced energy technology applications are briefly discussed. This article will provide inspiration for expanding the application of AB in the future.
Simplified Thermal Model for Absolute Radiometer Simulation
Authors: Lopes Andre Godoi , Irita Ricardo Toshiyuki , Berni Luiz Angelo , Vilela Waldeir Amaral , da Silva Savonov Graziela , Carlesso Franciele , Vieira Luis Eduardo Antunes , de Miranda Edson Luiz
Published: January 2021

The study of solar radiation in space has become something necessary, motivating the launch of radiometers on board satellites dedicated to perform total solar irradiance (TSI) measurements and to build a record of their behavior over the years, thus making these data essential for meteorology and climatology. In this study, we propose a simplified model to understand the thermal behavior of absolute radiometers, which are used in this type of measurement. The model considers the heat transfer among parts through conduction and loss only by radiation since the instrument operates in a space environment. The goal is to understand how each component interferes with sensitivity and response time of the instrument depending on its design, material, volume, and thermal contact. The model was applied to data generated by a prototype for validation.
Experimental Investigation of the Vibration Control of Nonrotating Periodic Drill Strings
Authors: Sassi Sadok , Renno Jamil , Zhou Han , Baz Amr
Published: January 2021

During the drilling process in oil and gas fields, slender drill strings often experience a multitude of complex and simultaneous vibrational phenomena. Drill string vibrations hinder the drilling process and can cause premature wear and damage to the drilling equipment. Here, the suppression of drill string vibrations during drilling operations is experimentally investigated using a novel drill string design, based on the use of innovative periodic inserts that control the vibration transmissibility in different directions. These inserts are equipped with viscoelastic rings that act as sources of local resonances, surrounding piezoelectric actuators that generate internal axial loading when electrically excited. An experimental prototype that combined all these details was constructed and tested to demonstrate the periodic drill string's feasibility and effectiveness in minimizing undesirable vibrations. The obtained results indicate that the periodic inserts’ careful design can effectively enhance the drill strings’ dynamic behavior and conveniently regulate its bandgap characteristics. Both radial and axial vibrations were controlled, and the vibrations’ amplitude was reduced significantly over a wide range of frequencies. The proposed approach appears to present a viable means for designing intelligent drill strings with tunable bandgap characteristics.
Modeling Analysis of the Wrist Dynamics via an Ellipsoidal Joint
Authors: Wang Jiamin , Gupta Sunit K. , Barry Oumar
Published: January 2021

An accurate wrist model is crucial to the understanding of human wrist mechanics and the development of forearm rehabilitation devices. This paper studied the nonlinear dynamics of the wrist through an ellipsoidal joint model. Compared to many studies where a universal joint is used to model the wrist, the proposed ellipsoidal model intends to better approximate the human wrist biomechanics with the use of kinematic constraints. The constraint on the original 3-dimensional rotation of the wrist is realized based on a quaternion formulation, reducing the wrist kinematics to the coupled 2-degree-of-freedom motions of flexion-extension and radial-ulnar deviation. The ellipsoidal joint also introduces additional coupling from the translational motion constraints. The multibody modeling of the wrist model is then established. The stability and control of the model are analyzed based on a constrained state-space model. Numerical simulations validate the analytical results and demonstrate the coupled dynamical behavior of the wrist. The simulations also show that the proposed model constraint is an ideal base regression function for wrist joint parameter identification. Finally, with the involvement of nonlinear stiffness and damping, chaotic-like behaviors and limit cycles are observed. The approach in this study is also generally applicable to a family of ellipsoidal joint systems.
On a Gamified Brain-Computer Interface for Cognitive Training of Spatial Working Memory
Authors: Liu Ziming , Bryan Jonathan , Borkoski Robert , Yuan Fengpei , Li Yansong , Zhao Xiaopeng
Published: January 2021

In the United States, there are a large number of people suffering from memory and attention deficit problems. For example, patients with attention-deficit hyperactivity disorder (ADHD) and dementia have difficulties in performing activities of daily living and have a low quality of life. Currently, there exist no effective treatment for these memory and attention issues in specific cognitive impairments. In this paper, we developed a gamified platform of brain-computer interface (BCI) for cognitive training, which can engage users in the training and provide users qualitative and quantitative feedback for their training of spatial working memory. The user is able to control the movement of a drone using motor imager, which is imagined movement of body part. Sensorimotor rhythms of the user are calculated using the user’s EEG to drive the movement of the drone. Twenty normal healthy subjects were recruited to test the user experience. Our system showed the capability of engaging users, good robustness, user acceptability and usability. Therefore, we think our platform might be an alternative to provide more accessible, engaging, and effective cognitive training for people with memory and attention problems. In future, we will test the usability and effectiveness of the system for cognitive training in patients with ADHD and dementia.
Adaptive Equivalent Factors of Multi-Objective Energy Management for Fuel Cell Hybrid Electric Vehicles
Authors: Ma Yan , Chen Jian , Wang Junmin
Published: January 2021

In this paper, a multi-objective energy management strategy with an adaptive equivalent factor is proposed to improve the fuel economy, system durability, and charge-sustenance performance of fuel cell hybrid electric vehicles. Firstly, the total hydrogen consumption and degradation cost of power sources can be calculated by flexible empirical models. Then, the multi-objective optimization problem can be transformed into an objective function, which can be solved by quadratic programming to improve the real-time performance. Furthermore, an adaptive Unscented Kalman filter is designed to estimate the aging state of the fuel cell system. The equivalent factor in the objective function can be adaptively updated by the estimated aging state, which can balance the conflict between the fuel economy and the system durability while keeping the state-of-charge in an ideal range. Finally, simulation results show that when the fuel cell system is obviously damaged during the operation, the proposed energy management strategy still can minimize the total cost and maintain the charge-sustenance performance under different driving cycles compared with other methods.
Optimal Control and Energy Management in Hybrid Turbojet Engines
Authors: Richter Hanz , Connolly Joseph W. , Simon Donald L.
Published: January 2021

Speed regulation with simultaneous electric and fuel energy management in electrified aircraft engines is considered. An optimal control approach is formulated and solved that uses a weighted measure of stored energy and fuel consumption as cost function. The semiactive virtual control technique, originally developed for robots with regenerative drives, is suitably extended and used to treat the torque applied by the electromechanical subsystem upon the engine as an independent control input to be optimized. The standard proportional-integral loop used for the primary fuel flow control is maintained for compatibility with industry practice and gain scheduling and limit management logic schemes. A single tunable weight reflects design preferences for fuel or stored electric energy preservation. The magnitude of the weight yields feedback gains which can effectively reverse the direction of power flow between the engine and the electromechanical system, providing a direct way to induce power extraction or injection in transient and steady regimes. In the steady-state, infinite-horizon case, the optimal torque controller is shown to reduce to simple proportional action on the shaft speed plus a bias, paralleling standard linear quadratic tracking with a custom cost function. The paper includes simulation results using the gas turbine model included in NASA’s open-source T-MATS package (Toolbox for the Modeling and Analysis of Thermodynamic Systems) and a representative electromechanical system.