bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification of myasthenia gravis and congenital myasthenic syndromes in dogs and cats
Authors: Mignan Thomas , Targett Mike , Lowrie Mark
Published: July 2020

Myasthenia, a syndrome of impaired neuromuscular transmission, occurs as either an acquired or congenital condition. Myasthenia gravis (MG) is an acquired autoimmune disorder with autoantibodies against the neuromuscular junction (NMJ) of skeletal muscle whereas congenital myasthenic syndromes (CMSs) are a clinically heterogeneous group of genetic disorders affecting the NMJ with a young age of onset. Both conditions are diseases for which recognition is important with regard to treatment and outcome. We review the published literature on MG and CMSs in dogs and cats, and by comparison with published classification used in humans, propose a classification system for MG and CMSs in dogs and cats. Myasthenia gravis is first classified based on focal, generalized, or acute fulminating presentation. It then is subclassified according to the autoimmune disease mechanism or seronegativity. Autoimmune disease mechanism relates to the presence or absence of a thymoma, or administration of thiourylene medication in cats. Congenital myasthenic syndromes are classified according to the affected NMJ component, the mechanism of the defect of neuromuscular transmission, the affected protein, and ultimately the mutated gene responsible. In proposing this categorization of MG and CMSs, we hope to aid recognition of the disease groups for both conditions, as well as guide treatment, refine prognosis, and provide a framework for additional studies of these conditions.
Hepatitis B surface antigen, core‐related antigen and HBV RNA: Predicting clinical relapse after NA therapy discontinuation
Authors: Kaewdech Apichat , Tangkijvanich Pisit , Sripongpun Pimsiri , Witeerungrot Teepawit , Jandee Sawangpong , Tanaka Yasuhito , Piratvisuth Teerha
Published: July 2020

Background & Aims

The safe discontinuation of nucleos(t)ide analogue therapy remains challenging in chronic hepatitis B. We investigated the potential role of quantitative hepatitis B surface antigen, hepatitis B core‐related antigen and hepatitis B virus RNA at the end of treatment in predicting off‐therapy relapse.

Methods

Patients who fulfilled the stopping criteria of the Asian Pacific Association for the Study of the Liver guideline were enrolled. Virological relapse was defined as hepatitis B virus DNA level greater than 2000 IU/mL, and clinical relapse was defined as virological relapse plus alanine aminotransferase level of more than twice the upper limit of normal.

Results

Ninety‐two patients participated. The combination of end‐of‐treatment hepatitis B core‐related antigen and hepatitis B virus RNA levels was most predictive of clinical relapse. Multivariate analysis revealed that end‐of‐treatment hepatitis B core‐related antigen and hepatitis B virus RNA were independently associated with clinical relapse. During follow‐up, no patients with undetectable hepatitis B core‐related antigen (<3.0 log10 U/mL) and hepatitis B virusRNA (<2.0 log10 copies/mL) at end of treatment developed clinical relapse, in comparison with 22.9% and 62.5% patients with detectable levels of one or both biomarkers respectively. End‐of‐treatment quantitative hepatitis B surface antigen was linked to a likelihood of hepatitis B surface antigen clearance.

Conclusions

The combined hepatitis B core‐related antigen and hepatitis B virus RNA assays at end of treatment were highly predictive of subsequent clinical relapse. These novel biomarkers could potentially be used to identify patients who could safely discontinue nucleos(t)ide analogue therapy.
Hepatitis C virus eradication by direct antiviral agents abates oxidative stress in patients with advanced liver fibrosis
Authors: Salomone Federico , Petta Salvatore , Micek Agnieszka , Pipitone Rosaria Maria , Distefano Alfio , Castruccio Castracani Carlo , Rini Francesca , Di Rosa Michelino , Gardi Concetta , Calvaruso Vincenza , Di Marco Vito , Li Volti Giovanni , Grimaudo Stefania , Craxì Antonio
Published: July 2020

Background and aims

HCV eradication improves non‐hepatic outcomes such as cardiovascular diseases, although without clearly defined mechanisms. In this study we aimed to assess whether improvement of carotid atherosclerosis may be linked to a reduction in systemic oxidative stress after viral clearance.

Methods

We studied a retrospective cohort of 105 patients (age 62.4 ± 11.2 years; 62 men) with F3/F4 fibrosis, characterized by carotid ultrasonography at baseline and at sustained virologic response (SVR) follow‐up. Levels of 8‐iso‐prostaglandin F2α (F2‐isoprostanes) and other oxidative stress markers were measured on frozen sera. Association between change (denoted as Δ) in oxidative stress markers (exposures) and change in carotid intima‐media thickness (cIMT) (outcome) was examined using multiple linear regression.

Results

Subclinical atherosclerosis, defined as the presence of carotid plaque and/or cIMT ≥ 0.9, was present in 72% of the cohort. All patients achieved SVR that led to reduction in cIMT (0.92 ± 0.20 vs 0.83 ± 0.21 mm, P < .001). HCV eradication markedly decreased serum levels of F2‐isoprostanes (620.5 [143.2; 1904.1] vs 119.51 [63.2; 400.6] pg/mL, P < .0001), lipid hydroperoxides (13.8 [6.3; 20.7] vs 4.9 [2.3; 9.6] nmol/μl, P < .0001) and 8‐hydroxy‐2'‐deoxyguanosine (558.9 [321.0; 6301.2] vs 294.51 [215.31; 408.95] pg/mL, P < .0001), whereas increased serum GPx activity (10.44 [4.6; 16.3] vs 13.75 [9.42; 20.63] nmol/min/mL, P = .001). By multiple linear regression analysis ΔcIMT was independently associated with ΔF2‐isoprostanes (β: 1.746 [0.948; 2.543]; P < .0001) after adjustment for age, baseline F2‐isoprostanes and baseline IMT.

Conclusions

Besides association of lipid peroxidation with severity of liver disease, the reduction in F2‐isoprostanes may be involved in the improvement of atherosclerosis after HCV eradication.
A large interhemispheric glioependymal cyst associated with partial defect of the corpus callosum in an elderly man
Authors: Takayama Mio , Kashiwagi Masayuki , Hara Kenji , Matsusue Aya , Waters Brian , Kubo Shin‐ichi
Published: July 2020

Interhemispheric cysts are congenital, and usually present symptoms during childhood. However, they are occasionally detected in adults. These cystic lesions are sometimes associated with defects of the corpus callosum. Although defects of the corpus callosum by themselves do not present clinical symptoms, they are often accompanied by other brain malformations. A man in his late 60s was found dead at the scene of a fire. At autopsy, his brain weighed 1223 g and had a large interhemispheric cyst, measuring 5.5 × 4.5 × 4.0 cm in size. The cyst contained clear fluid but was not connected to the ventricular system. On slices of the cerebrum, the corpus callosum did not connect the right and left cerebral hemispheres, and the right lateral ventricle was dilated. By the existence of the cyst, compressed by the cyst, the hemispheres were displaced on either side. Histologically, the cerebral parenchyma around the cyst was slightly edematous but structurally normal. Immunohistochemically, both glial fibrillary acidic protein and podoplanin were expressed in the cystic components. Thus, the cystic lesion was diagnosed as a glioependymal cyst. In this case, because the cyst was located at the interhemispheric space between the right and left frontal lobes, the individual experienced no obvious symptoms, despite its large size. The individual's brain malformations included the partial defect of the corpus callosum and the cyst. The dilation of the right lateral ventricle was considered to result from the location of the cyst. Under the influence of the cyst, the third ventricle was displaced downward, and one or both of the interventricular foramen were obstructed. The decedent had burns over his whole body. Burns to the epiglottis and soot in the airway were also observed. Volatile hydrocarbons, such as benzene and styrene, were detected in the blood. The percentage of carboxyhemoglobin levels in a total of hemoglobin levels were 19‐25%. Therefore, the individual's cause of death was established as death by fire.
Biomechanical correlates of sequential drinking behavior in aging
Authors: Cock Charles , Omari Taher I. , Burgstad Carly M. , Thompson Alison , Doeltgen Sebastian H.
Published: July 2020

Background

The timed water swallow test (TWST) is a test of sequential swallowing where a measured volume is ingested as quickly as comfortably possible. We undertook a study of the biomechanics underpinning the TWST in healthy young and older participants.

Methods

Thirty healthy volunteers underwent high‐resolution impedance manometry (MMS; Unisensor, 2.7 mm diameter, 32 pressure sensors, 16 impedance segments). Participants were asked to drink 150 mL, 0.9% normal saline solution rapidly. Swallowing biomechanics and bolus flow characteristics were assessed using pressure‐flow analysis and compared using t test and Fisher's exact test with significance as P < .05.

Key Results

Older participants (n = 18; 76 ± 11 years) took longer to complete the TWST (21.2 ± 2.5 vs 9.2 ± 1.0 seconds; P < .001) and displayed reduced volume per swallow (16.6 ± 1.3 vs 27.8 ± 2.9 mL; P < .001) compared to younger participants (n = 12; 29 ± 5 years). Two distinctive pharyngeal swallowing patterns were observed: (a) a single rapid sequence of swallows with or without a clearing swallow (Pattern I) or (b) multiple, shorter sequences interrupted and/or interspersed with single swallows or breaks (Pattern II). Some older participants showed biomechanical evidence of upper esophageal sphincter restriction (n = 7) or impaired deglutitive inhibition (n = 7), associated with the more prolonged Pattern II (TWST duration 30.1 ± 1.5 vs Pattern I 11.9 ± 1.5 seconds; P < .001).

Conclusions and Inferences

Healthy older participants had an increased duration of TWST, suggesting a need to adapt normative values for this population. Rapid sequential swallowing was associated with evidence of UES restriction and impaired deglutitive inhibition in some older participants.
Green space access in the neighbourhood and childhood obesity
Authors: Jia Peng , Cao Xinxi , Yang Hongxi , Dai Shaoqing , He Pan , Huang Ganlin , Wu Tong , Wang Yaogang
Published: July 2020

Access to green space may influence individual physical activity (PA) and subsequently weight status, as increased exposure to green space could improve health by increasing opportunities and the actual levels of PA. However, whether such associations hold empirically remains inconclusive. This study reviewed articles that analysed the association between access to green space and weight‐related behaviours/outcomes among children, published before 1 January 2019. The sample sizes ranged from 108 to 44 278. Four cohorts and 17 cross‐sectional studies conducted in nine countries were identified. Overall, evidence showed a positive association between access to green space and PA and a negative association between access to green space and television‐watching time, body mass index (BMI) and weight status among children. Distance to the nearest green space, measured by geographic information system (GIS) in 10 studies, was often used to represent access to the nearest green space. It still remains difficult to draw a clear conclusion on the association between access to green space and BMI. Longitudinal studies can directly estimate the strength of the association between exposure and disease, which is needed to determine the causal association between access to green space and weight status.
Divergence of defensive cucurbitacins in independent Cucurbita pepo domestication events leads to differences in specialist herbivore preference
Authors: Brzozowski Lauren J. , Gore Michael A. , Agrawal Anurag A. , Mazourek Michael
Published: July 2020

Crop domestication and improvement often concurrently affect plant resistance to pests and production of secondary metabolites, creating challenges for isolating the ecological implications of selection for specific metabolites. Cucurbitacins are bitter triterpenoids with extreme phenotypic differences between Cucurbitaceae lineages, yet we lack integrated models of herbivore preference, cucurbitacin accumulation, and underlying genetic mechanisms. In Cucurbita pepo, we dissected the effect of cotyledon cucurbitacins on preference of a specialist insect pest (Acalymma vittatum) for multiple tissues, assessed genetic loci underlying cucurbitacin accumulation in diverse germplasm and a biparental F2 population (from a cross between two independent domesticates), and characterized quantitative associations between gene expression and metabolites during seedling development. Acalymma vittatum affinity for cotyledons is mediated by cucurbitacins, but other traits contribute to whole‐plant resistance. Cotyledon cucurbitacin accumulation was associated with population structure, and our genetic mapping identified a single locus, Bi‐4, containing genes relevant to transport and regulation – not biosynthesis – that diverged between lineages. These candidate genes were expressed during seedling development, most prominently a putative secondary metabolite transporter. Taken together, these findings support the testable hypothesis that breeding for plant resistance to insects involves targeting genes for regulation and transport of defensive metabolites, in addition to core biosynthesis genes.
How Valuable Could a Person Be?*
Authors: Bailey Andrew M. , Rasmussen Joshua
Published: July 2020

We investigate the value of persons. Our primary goal is to chart a path fromequalandextremevalue toinfinitevalue. We advance two arguments. Each argument offers a reason to think that equal and extreme value are best accounted for if we are infinitely valuable. We then raise some difficult but fruitful questions about the possible grounds or sources of our infinite value, if we indeed have such value.
Movement competency and measures of isometric and dynamic strength and power in boys of different maturity status
Authors: Dobbs Ian J. , Oliver Jon L. , Wong Megan A. , Moore Isabel S. , Lloyd Rhodri S.
Published: July 2020

An understanding of how movement competency, strength, and power interact with natural growth and maturation is required in order to determine meaningful changes with developing athletes. Isometric and dynamic testing in youth athletes provides insight into the natural development of the force‐velocity (F‐V) spectrum. Two‐hundred and six young male athletes, aged 9‐17 years of age, were grouped according to stage of maturation based on their maturity offset which was determined as number of years from peak height velocity (PHV). All participants performed the back‐squat assessment (BSA), isometric mid‐thigh pull (IMTP), countermovement jump (CMJ), and squat jump (SJ) tests. Absolute and scaled force‐time variables were collected from the IMTP, CMJ, and SJ. No significant differences were observed between maturational groups for squat movement competency (P > .05). One‐way ANOVA with Bonferroni post‐hoc analysis revealed that increasing maturity led to significant, moderate to large increases in allometrically scaled peak force (PFallo) for all tests (P < .05). Multiple stepwise linear regression models revealed IMTP PFallo significantly predicted 34.8% and 41.3% of variance in SJ and CMJ jump height, respectively (P < .05). Natural growth and maturation induces positive adaptations to movement competency as well as isometric and dynamic strength and power. Trends from the IMTP, SJ, and CMJ tests indicate the largest differences in strength, and power may occur around the adolescent growth spurt despite the large variation in rates of change within the circa‐PHV group.
Indirect effects of the Family Check‐Up on youth extracurricular involvement at school‐age through improvements in maternal positive behavior support in early childhood
Authors: Feldman Julia S. , Zhou Yiyao , Krug Chelsea Weaver , Wilson Melvin N. , Shaw Daniel S.
Published: July 2020

Extracurricular involvement in the school‐age years has widespread potential benefits for children's subsequent socioemotional development, especially for low‐income youth. However, there is a dearth of research on interventions aimed at increasing school‐age extracurricular involvement in low‐income youth. Thus, the present study aimed to test the collateral effect of a brief, family‐focused intervention for low‐income families, the Family Check‐Up, on children's school‐age extracurricular involvement via improvements in maternal positive behavior support (PBS) in early childhood. The sample (n = 630, 50% female, 50% White, 28% Black/African American) represented a subsample of families from the Early Steps Multisite Study. At the age of two, families were randomly assigned to the Family Check‐Up or Women, Infants, and Children Nutritional Supplement Services as usual. Mother‐child dyads participated in observed interaction tasks at child ages 2 and 3 that were subsequently coded to assess PBS. Primary caregivers reported on children's school‐age extracurricular involvement at ages 7.5, 8.5, and 9.5. Results indicated that although there was not a direct path between intervention status and children's school‐age extracurricular involvement, a significant indirect path emerged from intervention group to changes in PBS between ages 2 to 3 to children's school‐age extracurricular involvement. The results are discussed in terms of implications for designing preventive interventions in early childhood that promote extracurricular involvement at school‐age, particularly for children at risk for maladaptive outcomes.
Interpersonal skills scale: Development and validation in urbanized sample of adolescents
Authors: Zahra Sayyeda Taskeen , Saleem Sadia , Subhan Sara , Mahmood Zahid
Published: July 2020

Interpersonal skills play a vital role in the growth and development of adolescents. The current study explored the experience and manifestation of interpersonal skills in Pakistani adolescents. In phase I, using open‐ended phenomenological approach, key components of interpersonal skills were elicited from 32 adolescents (boys = 16; girls = 16) aged 11–19 years (M = 14.48;SD = 1.06). In phase II, Content Validity Index for items (I‐CVIs) and scale (S‐CVI) was established. In phase III, pilot testing was carried out on 21 adolescents (boys = 11; girls = 10). In Phase IV, a sample of 674 adolescents (boys = 47%; girls = 53%) aged 11–19 years (M = 14.88;SD = 1.33) were tested for psychometric properties of Interpersonal Skills Scale along with Social Intelligence Scale for Adolescents and Self‐Esteem Scale for Children. Exploratory Factor Analysis (n = 221) generated three factors of the Interpersonal Skills Scalesocial engagement,sociability, andsocial etiquettes. Confirmatory Factor Analysis (n = 453) also supported the three‐factor structure of the Interpersonal Skills Scale. Furthermore, the scale found to have high internal consistency, construct validity, discriminant validity, split‐half reliability, and test–retest reliability. The results are discussed in the light of factorial structure in the Pakistani cultural context.
“We Need to Do Something About This”: Children and Youth’s Post‐Disaster Views on Climate Change and Environmental Crisis
Authors: McDonald‐Harker Caroline , Bassi Emilie M. , Haney Timothy J.
Published: July 2020

Research is increasingly uncovering the many ways that individuals affected by disasters change their environmental views in response to their direct experience of such catastrophic events. There is a growing body of research that focuses on adults’ environmental views, revealing that they often remain complacent toward environmental problems even after experiencing a disaster. However, very little research examines whether and to what extent children and youth’s environmental views shift and change after experiencing a disaster. This article fills this gap by specifically focusing on the environmental views and practices of 83 children and youth between the ages of 5 and 17 years who experienced the 2013 Southern Alberta Flood, the costliest flood disaster in Canadian history. Findings suggest that disaster catalyzes a process of reflexivity in children and youth. Experiencing the flood prompted children and youth to think more about the environment than prior to the flood; contemplate larger environmental issues, such as climate change, as the root cause of the locally experienced flood; and take action, as well as call others to action, to ameliorate climate and environmental problems in their own lives and communities. We discuss the implications these findings have for environmental and disaster education, policies, and practices.
Post‐truth politics and discursive psychology
Authors: Demasi Mirko A.
Published: July 2020

This article argues for the potential of discursive psychology (DP) in the study of post‐truth politics. Work produced outside of psychology is considered, particularly from political science and international relations, which have made a promising start. Providing an overview of this body of research, I argue for their respective strengths and weaknesses. The literature so far tends to work with the notion that truth and emotion are matters that are, or at least should be, distinguishable. Instead, I argue that, rather than lament the blurring between truth and untruth, one should look to how these unfold as matters of practical concern in political discourse. DP is a tool particularly suited to the task; it highlights the importance of viewing ‘truth’ as a rhetorical resource. In this light, we can view post‐truth politics as a rhetorical matter rather than a degeneration of truth.
Lipid kinases PIP5K7 and PIP5K9 are required for polyamine‐triggered K+ efflux in Arabidopsis roots
Authors: Zarza Xavier , Van Wijk Ringo , Shabala Lana , Hunkeler Anna , Lefebvre Matthew , Rodriguez‐Villalón Antia , Shabala Sergey , Tiburcio Antonio F. , Heilmann Ingo , Munnik Teun
Published: July 2020

Polyamines, such as putrescine, spermidine and spermine (Spm), are low‐molecular‐weight polycationic molecules present in all living organisms. Despite their implication in plant cellular processes, little is known about their molecular mode of action. Here, we demonstrate that polyamines trigger a rapid increase in the regulatory membrane lipid phosphatidylinositol 4,5‐bisphosphate (PIP2), and that this increase is required for polyamine effects on K+ efflux in Arabidopsis roots. Using in vivo 32Pi‐labelling of Arabidopsis seedlings, low physiological (μm) concentrations of Spm were found to promote a rapid PIP2 increase in roots that was time‐ and dose‐dependent. Confocal imaging of a genetically encoded PIP2 biosensor revealed that this increase was triggered at the plasma membrane. Differential 32Pi‐labelling suggested that the increase in PIP2 was generated through activation of phosphatidylinositol 4‐phosphate 5‐kinase (PIP5K) activity rather than inhibition of a phospholipase C or PIP2 5‐phosphatase activity. Systematic analysis of transfer DNA insertion mutants identified PIP5K7 and PIP5K9 as the main candidates involved in the Spm‐induced PIP2 response. Using non‐invasive microelectrode ion flux estimation, we discovered that the Spm‐triggered K+ efflux response was strongly reduced in pip5k7 pip5k9 seedlings. Together, our results provide biochemical and genetic evidence for a physiological role of PIP2 in polyamine‐mediated signalling controlling K+ flux in plants.
Thyroid hormone treatment improved the response to maximum exercise test and preserved the ventricular geometry in myocardial infarcted rats
Authors: Teixeira Rayane Brinck , Zimmer Alexsandra , Godoy Alessandra Eifler Guerra , de Castro Alexandre Luz , Campos‐Carraro Cristina , Belló‐Klein Adriane , da Rosa Araujo Alex Sander
Published: July 2020

New Findings

What is the central question of this study?

Does thyroid hormone treatment given after myocardial infarction preserve left ventricular function and treadmill exercise performance, and improve parameters of oxidative stress in the right ventricle and lungs of Wistar rats?

What is the main finding and its importance?

Thyroid hormone treatment improved the performance of the maximum exercise test in infarcted rats and induced effects in the heart and lungs that were similar to those observed with exercise training. This suggests there is a significant value of thyroid hormones for preserving exercise tolerance after myocardial infarction.

Left ventricular myocardial infarction (MI) provokes damage in the heart and in other tissues, such as right ventricle and lungs. The present study elucidated whether thyroid hormone treatment (THT) may present positive effects in heart and lungs after MI, and whether or not these effects are similar to those of exercise training (ET). Male Wistar rats were divided into four groups: sham operated (SHAM), infarcted (MI), infarcted + exercise training (MIE), and infarcted + thyroid hormones (MIH). A maximum exercise test, left ventricle echocardiography, pulmonary histology, and oxidative stress in the right ventricle and lung were evaluated. THT and ET both reduced left ventricular dilatation and end‐diastolic wall stress indexes to a similar extent. MI accentuated the content of macrophages and inflammatory infiltrate in the lungs, which was partially prevented in the MIH and MIE groups. THT and ET presented similar effects in the heart and lungs, and both improved the performance of the maximum exercise test in infarcted animals.
A Mixture Theory Model for Blood Combined With Low-Density Lipoprotein Transport to Predict Early Atherosclerosis Regions in Idealized and Patient-Derived Abdominal Aorta
Authors: Ameenuddin Mohammed , Anand Mohan
Published: July 2020

Genesis and onset of atherosclerosis are greatly influenced by hemodynamic forces. Two-phase transient computational fluid dynamic (CFD) simulations are performed using a mixture theory model for blood, and a transport equation for low-density lipoprotein (LDL), in idealized and patient-derived abdominal aorta to predict the sites at risk for atherosclerosis. Flow patterns at different time instants and relevant hemodynamic indicators—wall shear stress (WSS)-based (time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT)), and LDL concentration—are used concurrently to predict the susceptible sites of atherosclerosis. In the case of idealized geometry, flow recirculations are observed on the posterior wall opposite the superior mesenteric artery and below the renal bifurcations. Low TAWSS, high OSI, high RRT and high concentration of LDL are observed in these regions. This suggests that in idealized abdominal aorta, the posterior wall proximal to the renal artery junction is more prone to atherosclerosis. This matches qualitatively with the experimental and simulation data in the literature. In the case of patient-derived geometry, flow reversal, low TAWSS, high OSI and high RRT are observed infrarenal on the anterior wall. Further, high concentration of LDL is observed at the same location on the anterior wall suggesting anterior wall distal to the renal artery junction is more prone to atherosclerosis. These findings demonstrate the use of a novel method to predict the sites at risk for atherosclerosis in geometries where complexities like junctions and curvature play a major role.
Analysis Methods for High Energy Line Break Jet Flows in Nuclear Power Plants
Authors: Charrouf Marwan , Kauffman Storm , Yoon Jin-Kyoo , Lee Sang-Gyu , Kim Taejoon
Published: July 2020

The effects of postulated accidents, including dynamic effects of pipe ruptures, must be analyzed for licensing of nuclear power plants (NPPs). Applicants and licensees of NPPs have struggled to address U.S. Nuclear Regulatory Commission (NRC) expectations to assess if high energy line break (HELB) jet impingement on structures and components can lead to dynamic amplification, and to accurately simulate blast wave-induced loadings. In this paper, evaluation of the potential for load amplification and occurrence of resonance conclusively demonstrates that the phenomenon does not occur. In a HELB, several physical parameters of jets issuing from a ruptured pipe—such as nonequilibrium condensation of steam, unsteady separation between the jet exit and target, nonorthogonal alignment of jet axis to impingement surface, uneven impingement surfaces, or mismatch of jet excitation frequency and target natural frequency—prevent occurrence of the phase lock conditions needed to initiate and maintain a resonance. The analytical approach to evaluate the blast wave-induced loading applied a pressure vessel burst (PVB) correlation instead of performing computational fluid dynamics (CFD) analysis for all break locations. Three-dimensional (3D) CFD analysis of blast wave transient propagation provided the basis to develop benchmarking factors for use with the PVB correlation. The simplified methodology utilizes shockwave reflection, shape, and environment factors for application to impacted targets, which significantly reduces the amount of time to evaluate all break locations. The modified PVB method is also more appropriate than an explosion-type correlation to model the blast wave pressures from steam pipe breaks.
Thermomechanical Modeling of a Sleeve Rehabilitation System for Pressure Pipes
Authors: Pérez José David , Maury Heriberto , Bris Jorge , Ojeda Marianella
Published: July 2020

The thermomechanical modeling of a sleeve rehabilitation system for pressure pipes is studied including temperature effect on system behavior. The rehabilitation system consists of a multicylinder axisymmetric layer system, with an intermediate layer of epoxy resins and two outer steel covers that are longitudinally welded forming a sleeve. The analysis is conducted over several stages; initially, the incidence of temperature on the rigidity of three types of resins currently available on the market is experimentally evaluated. Then, nonlinear relationships between rigidity and temperature are established from the evaluation of the resins, which are typical of an inhomogeneous material. The resins exhibit a significant loss of rigidity with temperature, generating a risk of delamination that could drastically reduce the effectiveness of the rehabilitation system in the event of possible temperature rises. An analytical model was developed to calculate contact pressures between the resin layer and the external sleeve, internal pipeline displacements, stresses, and deformations. Finally, contour plots were developed for different temperature, pressure levels, and pipe thickness as a graphics tool to predict pipeline failure due to plastic deformation or rupture.
Experimental and Numerical Study on the Formation Mechanism of Flow Field in a Side-Ported Rotary Engine Considering Apex Seal Leakage
Authors: Fan Baowei , Zhang Yaoyuan , Pan Jianfeng , Wang Yuanguang , Otchere Peter
Published: July 2020

The aim of this research is to investigate the influences of apex seal leakage on the formation mechanism of flow field in a side-ported rotary engine by particle image velocimetry (PIV) and computational fluid dynamics (CFD). In this study, a PIV was used to acquire the two-dimensional (2D) flow field on the rotor housing central plane at an engine speed of 700 rpm. A three-dimensional (3D) dynamic simulation model considering leakage through apex seals was established and verified by the 2D-PIV experiment results. Thereafter, CFD analysis was used to further understand the 3D flow field in combustion chamber under the action of apex seal leakage. The simulation results showed that for the three engine speeds (2000, 3500, and 5000 rpm), in the intake stroke, the vortex generated in the front end of combustion chamber under the condition with no leakage, was strengthened and destroyed by the effects of the small (0.02 mm) and the large (0.08 mm) apex seal leakage gaps, respectively. As the apex seal leakage gap increased, the volume efficiency and the peak pressure decreased continuously. The volume efficiency and the peak pressure caused by any fixed apex seal leakage gap decreased with the increase of the engine speed. Compared with the volumetric efficiency of the condition with no leakage at 2000 and 5000 rpm, the volumetric efficiency of apex seal leakage gap of 0.08 mm decreased only by 24.6% at 5000 rpm, but by 41.2% at 2000 rpm.
Extending Engine Gas Path Analysis Using Full Flight Data
Authors: Tang Liang , Volponi Allan J. , Prihar Ethan
Published: July 2020

The ability to trend engine module performance and provide engine system fault detection and isolation are arguably, core capabilities for any engine Condition Based Maintenance (CBM) system. The origins of on-condition monitoring can be traced back nearly four decades, and a methodology known as Gas Path Analysis (GPA) has played a pivotal role in its evolution. Legacy Gas Path Analysis is a general methodology that assesses and quantifies changes in the underlying performance of the major modules of the engine (compressors and turbines), which in turn, directly affect overall performance measures of interest such as fuel consumption, power availability, compressor surge margins, and the like. Additionally, this approach is easily adapted to enable fault detection and identification of many engine system accessory faults such as variable stator vanes, handling and customer bleeds, sensor biases, and drift. Classical GPA has been confined to off-board analysis of averaged snapshot data when the engine is in steady state operation. This discrete data point approach, while reasonably accurate and repeatable, introduces a time latency to confidently detect and identify a faulty condition. Depending on the type and severity of the underlying fault, time to identify can be the differentiating factor in avoiding an unanticipated engine removal, flight delay or cancellation, in-flight engine shutdown, or catastrophic event. In this paper, we explore the use of streaming full flight data, which includes both transient and steady state operation. This type of data stream, when properly processed by gas path analysis and information fusion algorithms, allows faster anomaly detection, credible fault persistency checks, and timely fault identification within the current flight.
Numerical Investigations on the Static and Rotordynamic Characteristics of Hole-Pattern Seals With Annular or Pocket Grooves on Seal Stator
Authors: Fang Zhi , Li Zhigang , Li Jun , Feng Zhenping
Published: July 2020

Annular damper seals, such as hole-pattern seals, are widely used to control leakage and enhance rotordynamic stability in turbomachinery, especially for the balance-piston seal in the straight-through compressor, and the center seal in the back-to-back compressor. To avoid or minimize negative static stiffness, annular grooves on seal stator have been used to increase direct static stiffness of hole-pattern seals by dividing one long seal to several shorter seal sections. However, few literatures are available for understanding the influences of annular grooves on seal static and rotordynamic characteristics.

To understand the comprehensive effects of grooves on the static and rotordynamic characteristics of annular seals, a proposed three-dimensional (3D) transient CFD-based method was used for predictions of rotordynamic characteristics of hole-pattern seals, based on the multi-frequency one-dimensional rotor oscillating model and mesh deformation technique. Moreover, a 3D steady CFD-based method based on the mesh deformation technique was also utilized to predict static characteristics of hole-pattern seals. The accuracy and reliability of the present transient CFD-based method were demonstrated with experimental data of frequency-dependent rotordynamic coefficients of an experimental hole-pattern seal (HPS) at three inlet preswirl conditions (μ0 = −0.2441, 0, 0.598). The leakage flow rates, static and rotordynamic force coefficients were computed for three types of HPS (one without grooves - HPS, one with annular grooves on stator - HPS-AG, and one with pocket grooves on stator – HPS-PG) with three axial locations of grooves (20%, 40%, 60% of seal axial length) at zero and positive inlet preswirl conditions. The effects of groove types (annular and pocket grooves) and groove locations on the static and rotordynamic coefficients of HPS were numerically discussed.

Numerical results show that the annular groove and pocket groove on the seal stator both produce a significantly increase in static stiffness, and the HPS-PG seal possesses relatively optimal static stiffness. The annular groove and pocket groove both result in slight increase (less than 5%) in leakage flow rate. The annular groove will significantly weaken the seal dynamic stiffness capability but weakly influence the seal net damping capability. However, the pocket groove shows weakly influences on the dynamic stiffness and damping characteristics. This suggests that the pocket groove is a more suitable design to improve the static and rotordynamic characteristic. The rotordynamic force coefficients show strong dependence on the annular groove location for the HPS-AG seal, but are insensitive to the pocket groove location for the HPS-PG seal. The optimal location of annular groove is strongly related to the inlet preswirl conditions. The increasing swirl velocity induced by the annular groove results in the decrease in stiffness and damping of the HPS-AG seal.
Production and characterization of alginate bilayer membranes for releasing simvastatin to treat wounds
Authors: Monteiro Rubens T. , Andrade Fabia K. , Vasconcelos Niédja F. , Nogueira Karina A. B. , Petrilli Raquel , Vieira Rodrigo S.
Published: July 2020

This study aims to produce and characterize alginate bilayer membranes composed of single membranes with varying cross-linking degrees to modulate simvastatin release, with potential to be used for wound-dressing. The single-layer and bilayer membranes were characterized by weight, thickness, surface pH, equilibrium-humidity, swelling degree, solubility, infrared spectroscopy (attenuated total reflectance Fourier-transform infrared), scanning electron microscopy, and water vapor transmission. Simvastatin diffusion and release rates were analyzed using Franz’s cells; its indirect cytotoxicity was analyzed using human keratinocyte cells. The difference in the cross-linking degree (bottom and top layers) influenced the morphology of the membrane, and consequently its physical barrier properties. An in vitro release study demonstrated that the bilayer membrane could sustain drug-release for longer time as compared to the single-layer membrane, which could be potentially beneficial for long-term treatment of chronic wounds. A cell viability assay showed that simvastatin-loaded alginate membranes could be characterized as noncytotoxic, demonstrating their potential for use in wound-dressing applications.
Pathogen associated molecular pattern-decorated mesoporous silica—A colloidal model for studying bacterial-host cell interactions
Authors: Valdemar-Aguilar Carlos M. , Manisekaran Ravichandran , Avila Remy , Compeán-García Vicente D. , Nava-Mendoza Rufino , Lopez-Marin Luz M.
Published: July 2020

Tuberculosis is the top infectious disease worldwide and the development of a vaccine and diagnostic tools to control the disease is a priority that requires a better understanding of the factors involved in the pathogenesis of Mycobacterium tuberculosis, the infectious agent. It is known that bacterial cell surface components are released, interact with immune cell receptors, and may traffic toward host cell structures. Many of these compounds are lipids that have been associated with mycobacterial virulence. However, their hydrophobic nature has frequently hampered their biological study. In this work, silica particles were coated with functional lipids to obtain a colloidal bioinspired system based on nonhydrosoluble glycolipids. Mycobacterium tuberculosis phosphatidylinositol mannosides (PIMs), known to interact with receptors of innate immune cells, were purified from the M. tuberculosis H37Rv type strain, and used to prepare large unilamellar liposomes in combination with zwitterionic phosphatidyl choline. Then, bacillary-like Santa Barbara Amorphous-15 (SBA-15) silica particles were cationized and the vesicle fusion method was used to promote the attachment of anionic PIM-containing lipid bilayers. Thermogravimetric analysis, x-ray diffraction, N2 adsorption-desorption isotherm analysis, Fourier transform infrared spectroscopy, electron microscopy, and zeta potential analyses were used to characterize the materials obtained. The as-prepared PIM-containing colloids, named PIM@SBA-15, showed biocompatibility toward human fibroblasts and were found to colocalize with Toll-like receptor (TLR)2 upon their incubation with THP1-derived macrophages. Furthermore, the particles induced the formation of pseudopods and were internalized into phagocytic cells. In all, these data suggest the usefulness of PIM@SBA-15 particles to better comprehend the interactions between immune cells and PIMs.
Randomized Clinical Trial of Water-Based Aerobic Training in Older Women (WATER Study): Functional Capacity and Quality of Life Outcomes
Authors: Andrade Luana Siqueira , Pinto Stephanie Santana , Silva Mariana Ribeiro , Campelo Paula Carolini , Rodrigues Samara Nickel , Gomes Mariana Borba , Krüger Vitor Lima , de Ferreira Graciele Ferreira , Alberton Cristine Lima
Published: July 2020

Background: The purpose of this study was to investigate the effects of 2 water-based aerobic training programs on functional capacity and quality of life (QoL) of older women. Design: Randomized clinical trial. Methods: A total of 41 women (64.3 [3.1] y) were randomized into a continuous (CTG) and an interval (ITG) water-based aerobic training group. Training programs were performed with exercise intensity based on rating of perceived exertion throughout 12 weeks (twice a week). Functional tests with and without dual-task and QoL questionnaire were applied pretraining and posttraining. Per protocol and intention to treat analysis were conducted using generalized estimating equations, with Bonferroni post hoc test (α = .05). Results: The per protocol analysis showed an increase in the 30-second chair stand (6% [12%] vs 18% [13%]), 6-minute walk (4% [7%] vs 2% [8%]), and 5-m habitual gait velocity (6% [11%] vs 4% [7%]) tests after CTG and ITG training groups. In addition, the intention to treat analysis revealed an increase in the 30-second chair stand test (7% [13%] vs 12% [13%]) and physical domain of QoL (8% [26%] vs 14% [22%]) after CTG and ITG training groups, as well as an increase in the gait velocity with verbal task after CTG (6% [11%]). Conclusions: Both water-based aerobic training programs induced similar improvements in the functional capacity and maintained the QoL perception in older women.
2018 Chilean Physical Activity Report Card for Children and Adolescents: Full Report and International Comparisons
Authors: Aguilar-Farias Nicolas , Miranda-Marquez Sebastian , Martino-Fuentealba Pia , Sadarangani Kabir P. , Chandia-Poblete Damian , Mella-Garcia Camila , Carcamo-Oyarzun Jaime , Cristi-Montero Carlos , Rodriguez-Rodriguez Fernando , Delgado-Floody Pedro , Von Oetinger Astrid , Balboa-Castillo Teresa , Peña Sebastian , Cuadrado Cristobal , Bedregal Paula , Celis-Morales Carlos , Garcia-Hermoso Antonio , Cortínez-O’Ryan Andrea
Published: July 2020

Background: The study summarizes the findings of the 2018 Chilean Report Card (RC) on Physical Activity (PA) for Children and Adolescents and compares the results with the first Chilean RC and with other countries from the Global Matrix 3.0. Methods: A Research Work Group using a standardized methodology from the Global Matrix 3.0 awarded grades for 13 PA-related indicators based on the percentage of compliance for defined benchmarks. Different public data sets, government reports, and papers informed the indicators. Results: The grades assigned were for (1) “behaviors that contribute to overall PA levels”: overall PA, D−; organized sport participation, D−; active play, INC; and active transportation, F; (2) “factors associated with cardiometabolic risk”: sedentary behavior, C−; overweight and obesity, F; fitness, D; sleep, INC; and (3) “factors that influence PA”: family and peers, F; school, D; inclusion, INC; community and built environment, B; government strategies and investments, B−. Conclusions: Chile’s grades remained low compared with the first RC. On the positive side, Chile is advancing in environmental and policy aspects. Our findings indicate that the implementation of new strategies should be developed through collaboration between different sectors to maximize effective investments for increasing PA and decreasing sedentary time among children and adolescents in Chile.
Targeting brain metastases with ultrasmall theranostic nanoparticles, a first-in-human trial from an MRI perspective
Authors: Verry Camille , Dufort Sandrine , Lemasson Benjamin , Grand Sylvie , Pietras Johan , Troprès Irène , Crémillieux Yannick , Lux François , Mériaux Sébastien , Larrat Benoit , Balosso Jacques , Le Duc Géraldine , Barbier Emmanuel L. , Tillement Olivier
Published: July 2020

Intravenously injected theranostic Gd-based nanoparticles enable targeting and MRI detection of brain metastases in patients.
ARID1A loss in neuroblastoma promotes the adrenergic-to-mesenchymal transition by regulating enhancer-mediated gene expression
Authors: Shi Hui , Tao Ting , Abraham Brian J. , Durbin Adam D. , Zimmerman Mark W. , Kadoch Cigall , Look A. Thomas
Published: July 2020

ARID1A is a tumor suppressor in neuroblastoma, whose loss promotes the adrenergic-to-mesenchymal transition.
Beyond the cell factory: Homeostatic regulation of and by the UPR
ER
Authors: Metcalf Melissa G. , Higuchi-Sanabria Ryo , Garcia Gilberto , Tsui C. Kimberly , Dillin Andrew
Published: July 2020

The UPR
ER
is generally considered a protein homeostasis machinery, but this review uncovers many additional functions of UPR
ER
.
Ionic spiderwebs
Authors: Lee Younghoon , Song Won Jun , Jung Yeonsu , Yoo Hyunjae , Kim Man-Yong , Kim Ho-Young , Sun Jeong-Yun
Published: July 2020

Ionic spiderwebs emulate the capturing strategies of a spider with a single pair of threads based on electrostatics.
Spinning artificial spiderwebs
Authors: Rossiter Jonathan
Published: July 2020

Sensing, adhesion, and self-cleaning capabilities are demonstrated in artificial spiderwebs through electrostatic actuation and a dirt-shirking coating.
A bug’s-eye view
Authors: Aloimonos Yiannis , Fermüller Cornelia
Published: July 2020

An insect-scale visual sensing system indicates the return of active vision for robotics.
Ethical challenges for pediatric liver organoid transplantation
Authors: Schneemann Sarah A. , Boers Sarah N. , van Delden Johannes J. M. , Nieuwenhuis Edward E. S. , Fuchs Sabine A. , Bredenoord Annelien L.
Published: July 2020

The authors discuss whether it is ethically acceptable to include children in a first-in-human clinical trial of liver organoid transplantation.
STING differentially regulates experimental GVHD mediated by CD8 versus CD4 T cell subsets
Authors: Bader Cameron S. , Barreras Henry , Lightbourn Casey O. , Copsel Sabrina N. , Wolf Dietlinde , Meng Jingjing , Ahn Jeonghyun , Komanduri Krishna V. , Blazar Bruce R. , Jin Lei , Barber Glen N. , Roy Sabita , Levy Robert B.
Published: July 2020

STING differentially regulates experimental graft-versus-host disease mediated by distinct T cell subsets.
Mapping the tumor frontline
Authors: Billi Allison C.
Published: July 2020

In cutaneous squamous cell carcinoma, a tumor-specific cell type at the leading edge may drive stromal and immune changes that facilitate progression.
Plasma proteins have a ticket to ride the blood-brain barrier
Authors: Davis Albert A.
Published: July 2020

Analysis of labeled plasma proteins reveals a shift from receptor-mediated brain uptake to less specific transcytosis that occurs with aging.
Care packages for the bone marrow
Authors: Kanakry Christopher G.
Published: July 2020

Platelets secrete extracellular vesicles that can traffic to the bone marrow and stimulate megakaryopoiesis.