bluuebunny/crossref_metadata_2025 huggingface dataset:
Salivary and gingival CXCL8 correlation with periodontal status, periodontal pathogens, and smoking
Authors: Frasheri Iris , Heym Richard , Ern Christina , Summer Burkhard , Hennessen Till G. , Högg Christof , Reichl Franz‐Xaver , Folwaczny Matthias
Published: August 2021

Objectives

Neutrophil granulocytes have been proposed to play a major role in the mediation of periodontitis‐associated tissue destruction. Their recruitment and activation are regulated by the chemokine CXCL8. This study aimed to delineate the dependency of CXCL8 expression in gingival crevicular fluid (GCF) and saliva on periodontal status, bacterial infection, and smoking, in patients with periodontitis.

Methods

The study cohort comprised 279 subjects with untreated periodontitis. Probing pocket depth (PPD), gingival recession, bleeding on probing (BOP), plaque index, and bone loss were evaluated. CXCL8 was determined in saliva and GCF using flow cytometry.

Results

Considering the entire study sample, CXCL8 levels were correlated with the mean PPD (ρ = 0.131; p = 0.029), severity of periodontitis (ρ = 0.121; p = 0.043), BOP (ρ = 0.204; p = 0.001), and smoking (ρ = −0.219; p < 0.0001) in GCF; and, in whole saliva, with mean PPD (ρ = 0.154; p = 0.010) severity of periodontitis (ρ = 0.140; p = 0.020), gender (ρ = 0.178; p = 0.003), and smoking (ρ = −0.156; p = 0.010). Subgroup analysis among non‐smokers revealed significantly higher amounts of CXCL8 in GCF (p = 0.012) and saliva (p = 0.026) comparing subjects with mean PPD ≤3mm and >3mm.

Conclusion

The current study revealed a strong dependency of CXCL8 expression in GCF on the severity and activity of periodontal disease. Smoking causes a significant reduction in CXCL8 expression in saliva and GCF.
Triggering receptor expressed on myeloid cells‐2 stimulates osteoclast differentiation and bone loss in periodontitis
Authors: Pei Qing‐guo , Wang Hai‐cheng , Li Lin , Wang Zuo‐lin
Published: August 2021

Objective

To investigate the expression of triggering receptor expressed on myeloid cells 2 (TREM‐2) in the healthy and diseased tissue, including gingivitis or periodontitis, and then to assess whether it has an impact on the development of periodontitis.

Methods and materials

The gingival tissues from healthy controls, gingivitis, and periodontitis underwent hematoxylin–eosin and immunohistochemical staining, and the association of TREM‐2 expression or TREM‐2+ cell counts with clinical parameters was assessed. An anti‐TREM‐2 antibody was used to block the osteoclastogenesis in vitro and during the experimental periodontitis by injection into the gingiva. The relative gene expression of TREM‐2 in different gingival tissues was analyzed by quantitative PCR.

Results

In the gingival tissues of periodontitis, TREM‐2 expression and TREM‐2+ cell counts were significantly higher than those of gingivitis and healthy controls (p<0.05). In the group of periodontitis showing moderate signs, the gingival tissues displayed significantly lower TREM‐2 expression, in contrast with the group with advanced periodontal symptoms (p < 0.05). Consistently, blocking TREM‐2 significantly decreased osteoclast formation both in vitro and in vivo (p < 0.05).

Conclusion

Increased TREM‐2 expression and TREM‐2+ cells were positively associated with the development of periodontitis. Osteoclast differentiation and stimulating alveolar bone loss were partly relied on TREM‐2, which could be a target to be blocked for attenuating osteoclastogenesis in periodontitits.
Bidirectional ventricular tachycardia induced by respiratory alkalosis mediated hypokalemia in a patient with acute ischemic heart failure
Authors: Kulahcioglu Seyhmus , Baysal Pınar Karaca , Kup Ayhan , Imanov Elmin , Uslu Abdulkadir , Demir Serdar , Gulsen Kamil
Published: August 2021

Bidirectional ventricular tachycardia (BVT) is a rare arrhythmia that is generally observed in patients with catecholaminergic ventricular tachycardia or digoxin overdose. Herein, we present a case of BVT and electrical storm (ES) in an acute ischemic heart failure patient that is typically induced by hypokalemia. The patient was in invasive mechanical ventilator (MV) support and hypokalemia was related to acute respiratory alkalosis and that caused refractory hypokalemia despite intravenous (IV) potassium replacement. We also discuss our approach to solve refractory hypokalemia caused by respiratory alkalosis.
Embodiment in online psychotherapy: A qualitative study
Authors: García Enara , Di Paolo Ezequiel A. , De Jaegher Hanne
Published: August 2021

As a result of the COVID‐19 pandemic, many therapists and patients have been required to switch to online sessions in order to continue their treatments. Online psychotherapy has become increasingly popular, and although its efficacy seems to be similar to face‐to‐face encounters, its capacity to support the implicit nonverbal and embodied aspects of the therapeutic relationship has been questioned and remains understudied.

Objectives

To study how embodied and intersubjective processes are modified in online psychotherapy sessions.

Design

Taking the enactive concept of participatory sense‐making as a guiding thread, we designed an interpretative phenomenological analysis to examine the experiences of embodiment in online therapy.

Methods

We conducted phenomenological semi‐structured interviews with patients and therapists who have recently switched from face‐to‐face encounters to online modality.

Results

Adjustments in verbal and nonverbal behavior, gaze behavior, management of silences, and displacements of non‐intentional and pre‐reflective patterns onto reflective ones are reported as necessary to compensate for changes introduced in the online modality.

Conclusions

From an enactive perspective, such adaptations manifest regulatory processes aimed at sustaining interactive dynamics and coordinating the primordial tension between relational and individual norms in social encounters.

Practitioner points

We examine different aspects of embodiment that practitioners should take into account when switching from face‐to‐face to online encounters with their clients.

Online communication systems can alter aspects of the therapeutic relationship, such as its structure, its fragility, and its significance.

Video calls afford new forms of intervention such as integrating the experience of patients with their self‐image, incorporating information about their habitual environment into the process, and adopting less confrontational therapeutic styles.
Invasive candidiasis in a neonatal intensive care unit in Fukuoka
Authors: Ohta Eiji , Setoue Takashi , Ito Kazutoshi , Kodera Tatsurou , Onda Yasuhiro , Kawano Hiroyasu , Niimi Toshikazu , Kakura Hiroya , Morii Mariko , Miyamoto Tatsuki , Hashiguchi Chizuru , Nakamura Masatoshi , Hirose Shinichi
Published: August 2021

Background

Invasive candidiasis (IC) is a leading cause of morbidity and mortality in preterm infants. The objective of this study was to determine the prevalence of IC infection in newborns in the neonatal intensive care unit (NICU) of a tertiary hospital in Japan, and to identify specific predisposing factors for IC.

Methods

We retrospectively collected data on demographics, clinical characteristics, and outcomes of infants with IC, who were discharged from a tertiary NICU in Japan between January 2009 and December 2020. We compared predisposing factors associated with the occurrence of early‐onset IC (EOIC < 72 h) and late‐onset IC (LOIC ≥ 72 h) with those of early‐onset and late‐onset bacterial sepsis.

Results

Between January 2009 and December 2020, 3,549 infants were admitted to the NICU, including 344 extremely‐low birthweight (ELBW) infants. Eleven infants (including nine ELBW infants) had IC (incidence 0.31%), and the mortality rate of IC was 0%. Four (36%) infants had EOIC and seven (64%) had LOIC. All those with EOIC presented with skin lesions and 86% with LOIC had thrombocytopenia. Maternal vaginal Candida colonization was a more specific predisposing factor for EOIC, while gestational age <26 weeks, broad‐spectrum antibiotic use, prior bacterial infection, prior gastrointestinal (GI) surgery, and GI diseases were more specific predisposing factors for LOIC.

Conclusions

The findings suggest that maternal vaginal Candida colonization and skin lesions in ELBW infants may contribute to early recognition of EOIC. LOIC should be suspected if ELBW infants with several predisposing factors of LOIC have thrombocytopenia.
Patient background related to success and adverse event in pediatric sedated MRI
Authors: Konda Yutaka , Mihira Hajime , Akiyama Louis , Shiko Yuki , Ozawa Yoshihito , Kawasaki Yohei , Fujii Katsunori , Hiramoto Ryugo
Published: August 2021

Background

The success rate of sedation with triclofos sodium and midazolam for pediatric magnetic resonance imaging (MRI) has been reported. However, there are no reports of an association of adverse events and examination success rates with patient medical backgrounds using a combination of these sedatives. We performed this study to investigate these points.

Methods

We investigated 191 pediatric patients who were sedated for MRI with triclofos sodium and midazolam at Matsudo City Hospital between November 2013 and October 2015. We surveyed the patients' characteristics, including age, sex, body weight, allergies, medication, neuromuscular, gastrointestinal, respiratory, and cardiac disorders, airway obstruction factors, and developmental disorders. Outcomes were sedation success and adverse events, including oxygen desaturation. We reviewed the relationship between patient backgrounds and each adverse event or success rate of sedation.

Results

Among all cases, the success rate was 92.7%. Older age (odds ratio [OR] = 0.984), developmental disorders (OR = 0.215), and respiratory disorders (OR = 0.353) were factors for lower success rates. Adding midazolam was associated with a higher success rate (OR = 5.971), but the higher total dose of midazolam was associated with sedation failure (OR = 0.003). The only adverse event was oxygen desaturation (11.5%). Older age affected oxygen desaturation with multiple analysis. However, by stepwise analysis, no patient medical background nor sedative dose was associated with oxygen desaturation.

Conclusions

Older age, developmental disorders, and respiratory disorders were associated with sedation failure. Increasing midazolam did not increase the success rate, and there might be an optimal dose of midazolam.
Evaluation of children and adolescent with cystic fibrosis by pancreatic elastography
Authors: Yılmaz Kamil , Hattapoğlu Salih , Şen Velat , Karabel Müsemma , Kan Ahmet , Yılmaz Engin Deniz , Selimoglu Sen Hadice , Yılmaz Sureyya
Published: August 2021

Background

Cystic fibrosis (CF) is an autosomal recessively inherited disease. Clinical findings vary by age of the patient, the organ systems involved, and the severity of the CFTR gene mutation. Pancreatic and liver involvement is prominent and exocrine pancreatic insufficiency is observed in the majority of patients. Point shear wave elastography (pSWE) is a non‐invasive method that can quantitatively determine tissue elasticity and stiffness.

In this study, the morphological evaluation of the pancreas was performed using the pSWE technique in pediatric patients diagnosed with CF. The effectiveness of this method for the early detection of pancreatic insufficiency was investigated.

Methods

Fifty‐five patients with CF (24 girls, 31 boys) and 60 healthy children (29 girls, 31 boys) without any chronic diseases and who were suitable for the pSWE examination were included in the study.

Results

The mean value of pSWE was 1.12 ± 0.16 in the healthy group and 0.97 ± 0.16 in the patients with cystic fibrosis. There was a statistically significant difference between the two groups (P < 0.001). Significant negative correlations were found between pSWE and age (r = −0.319; P = 0.018), height (r = −0.293; P = 0.03), serum glucose (r = −0.346; P = 0.01), HbA1C (r = −0.592; P = 0.02), and duration of the disease (r = −0.806; P < 0.001).

Conclusions

Investigating pancreatic elasticity and detecting pancreatic insufficiency using pSWE (a simple, inexpensive, and non‐invasive method) in the early period before overt laboratory and clinical symptoms of EPI appear can contribute positively to long‐term results in young patients with CF.
Inherited metabolic disorders in the neonatal intensive care unit: Red flags to look out for
Authors: Eminoğlu Fatma Tuba , Koç Yekedüz Merve , Doğulu Neslihan , Öncül Ümmühan , Köse Engin , Okulu Emel , Erdeve Ömer , Atasay Begüm , Arsan Saadet
Published: August 2021

Background

We aimed to assess symptoms, laboratory findings, and radiological abnormalities in patients diagnosed with inherited metabolic disorders (IMDs) in the neonatal intensive care unit.

Methods

A total of 6,150 newborns treated in a third‐level neonatal intensive care unit between 2012 and 2020 in Turkey were screened, of which 195 consulted with a suspicion of metabolic disease based on their clinical, laboratory, or radiological findings were included in the present study.

Results

The prevalence of IMDs in the patients was 1:94.6. Those consulted in the department of pediatric metabolism were divided into two groups, with the 65 diagnosed with IMDs assigned as Group I, and the 130 patients who were not diagnosed with IMDs as Group II. The most common IMDs were organic acidemias (29.23%) and urea cycle disorders (UCDs) (26.15%). The rates of consanguinity marriage (75.3% vs 37.6%, P < 0.001), siblings diagnosed with an IMD (27.6% vs 3.8%, P < 0.001), and sibling death (56.9% vs 14.6%, P < 0.001) were higher in Group I than in Group II. Hyperammonemia (61.5% vs 18.4%, P < 0.001) was the most common laboratory finding in Group I, and anemia (Group I 60.0% vs 43.0% P = 0.033), metabolic acidosis (53.8% vs 36.9%, P = 0.028) and respiratory alkalosis (16.9% vs 1.5%, P < 0.001) were all higher in Group I.

Conclusions

This retrospective study found that the results of clinical findings and basic laboratory tests could be strong indicators of IMDs, although extensive newborn screening tests and advanced biochemical and genetic tests should be carried out for the diagnosis of IMDs in newborns.
Covalent Triazine Framework as an Efficient Photocatalyst for Regeneration of NAD(P)H and Selective Oxidation of Organic Sulfide
Authors: Chaubey Surabhi , Yadav Rajesh K. , Tripathi Santosh K. , Yadav Bal Chandra , Singh Sudhir N. , Kim Tae Wu
Published: August 2021

Covalent triazine frameworks (CTFs), belonging to the super‐family of covalent organic frameworks, have attracted significant attention as a new type of photosensitizer due to the superb light‐harvesting ability and efficient charge transfer originating from the large surface area. However, the wide optical band gap in CTFs, which is larger than 3.0 eV, hinders the efficient light harvesting in the visible range. To overcome this limitation, we developed the new type CTFs photocatalyst based on the donor–acceptor conjugation scheme by using melamine (M) and 2,6‐diaminoanthraquinone (AQ) as monomeric units. The melamine‐2,6‐diaminoanthraquinone‐based covalent triazine frameworks (M‐AQ‐CTFs) photocatalyst shows the excellent light‐harvesting capacity with high molar extinction coefficient, and the suitable optical band gap involving the internal charge transfer character. Combination of M‐AQ‐CTFs and artificial photosynthetic system including the organometallic rhodium complex, acting as an electron mediator, exhibited the excellent photocatalytic efficiency for the regeneration of the nicotinamide cofactors such as NAD(P)H. In addition, this photocatalyst showed the high photocatalytic efficiency for the metal‐free aerobic oxidation of sulfide. This study demonstrates the high potential of CTFs photocatalyst with the donor–acceptor conjugated scheme can be actively used for artificial photosynthesis.
Cardiac response in aversive and appetitive olfactory conditioning: Evidence for a valence‐independent CS‐elicited bradycardia
Authors: Exner Anna , Tapia León Isabell , Mueller Erik M. , Klucken Tim
Published: August 2021

While the examination of conditioned cardiac responses is well established in human fear conditioning research, comparable studies using less‐aversive or rather appetitive unconditioned stimuli (UCS) are sparse and results are mixed. Therefore, the aim of this study was a systematic analysis of cardiac reactions in aversive and appetitive conditioning. Olfactory stimuli were used as unconditioned stimuli as they are suitable reinforcers in both an aversive and an appetitive conditioning offering the opportunity for a comparison between conditioned responses. In total,n = 86 participants took part in both an aversive and an appetitive differential conditioning task with a counterbalanced order across participants. Aversive or appetitive odors, respectively, served as UCS and neutral geometrical figures as CS. Subjective ratings, skin conductance response (SCRs), and evoked cardiac reactions were analyzed and compared between tasks. Conditioned responses in subjective ratings could be observed in both aversive conditioning and appetitive conditioning, while SCRs discriminated between CS+ and CS− in aversive conditioning only. Regarding conditioned cardiac responses, the deceleration for the CS+ was longer than for the CS− in both tasks. In addition, a higher deceleration magnitude and a shorter acceleration for the CS+ as compared to the CS− were found in aversive but not in appetitive conditioning. There were medium‐size correlations between aversive and appetitive CRs for subjective ratings and none for physiological responses. The results suggest similarities between cardiac response patterns in aversive and appetitive conditioning, which implies that bradycardia in conditioning might not be fear‐specific but presents a valence‐independent CS‐elicited bradycardia.
The influence of environmental drivers and restoration intervention methods on postmine restoration trajectories
Authors: Mounsey Cameron M. , Stevens Jason C. , Renton Michael , Dixon Kingsley W. , Miller Ben P.
Published: August 2021

Mining activity causes major changes in site topography, soil physical and chemical properties, hydrology, and biological assemblages. Reassembling plant communities in these highly altered environments is dependent on interactions between environmental drivers and management intervention techniques through time, yet the long‐term effects of these interactions have rarely been quantified. This study examined a 19‐year‐old, postmining woodland restoration chronosequence in southwest Australia to understand plant community compositional development in postmine restoration sites. We tested the effects of environmental drivers (rainfall regimes, site aspect, slope) and management intervention techniques (substrate ripping and material properties) in terms of four restoration criteria: species richness, plant density, vegetation cover, and compositional similarity to reference sites. Irrespective of environmental drivers or management intervention techniques, vegetation cover increased through time, while plant density and species richness declined. Bray–Curtis similarity to reference communities remained unchanged. Within these trends, ripping and first‐year rainfall significantly affected restoration criteria outcomes; species richness and plant density were greatest when rainfall in the first winter immediately following site restoration was low but followed by a high summer rainfall. The most effective ripping depth was dependent on rainfall, deep‐ripped sites performed best when rainfall was high, and nonripped sites performed best under low‐mean rainfall conditions. Measured restoration criteria had not reached the levels of the target reference community after 19 years, which may be attributable to the still‐developing vegetation structure. This emphasizes the importance of assessing postmining restoration outcomes over longer time frames (>>5 years) with implications for determining appropriate, time‐dependent completion criteria.
The binary Darboux transformation revisited and KdV solitons on arbitrary short‐range backgrounds
Authors: Rybkin Alexei
Published: August 2021

In the KdV context, we revisit the classical Darboux transformation in the framework of the vector Riemann–Hilbert problem. This readily yields a version of the binary Darboux transformation providing a short‐cut to explicit formulas for solitons traveling on a wide range of background solutions. Our approach also links the binary Darboux transformation and the double commutation method.
Understudied questions of Key's friends and neighbors voting thesis
Authors: Frendreis John , Tatalovich Raymond
Published: August 2021

Objectives

This study addressesfour questions posed by V.O. Key's friends‐and‐neighbors (F&N) voting thesis that have been neglected in the scholarly literature.

Methods

Pooled regression of 101 primary and 66 general elections in Mississippi, South Carolina, Pennsylvania, and Wisconsin for the offices of U.S. senator and governor over the period 2002–2016 yielded a total of 11,263 candidate‐county cases.

Results

F&N effects are most pronounced in primary elections, for Democratic candidates, and for nonincumbents. Also greater F&N effects for candidates whose “home” county populations were less well educated. The relative importance of F&N effects is displaced by social cleavage variables in elections where they are relevant to voter choices, namely general elections rather than primaries.

Conclusion

This study begs the larger question for future research of why F&N has greater effect for Democrats than Republicans and whether more Democrats tend to be low‐information voters.
Exploring geographic hotspots using topological data analysis
Authors: Zhang Rui , Lukasczyk Jonas , Wang Feng , Ebert David , Shakarian Paulo , Mack Elizabeth A. , Maciejewski Ross
Published: August 2021

This article describes a scalar field topology (SFT)‐based methodology for the interactive characterization and analysis of hotspots for density fields defined on a regular grid. In contrast to the common approach of simply identifying hotspots as areas that exceed a chosen density threshold, SFT provides various data abstractions—such as the merge tree and the Morse complex—to characterize hotspots and their boundaries at multiple scales. Moreover, SFT enables the ranking of hotspots based on analyst‐defined importance measures, which also makes it possible to explore hotspots using a level‐of‐detail approach. We present a visual analytics system to support analysts in hotspot analysis and abstraction using SFT, and we demonstrate the merit of the proposed SFT‐based methodology on two crime datasets.
Molecular validation of pathogen‐reduction technologies using rolling‐circle amplification coupled with real‐time PCR for torquetenovirus DNA quantification
Authors: Focosi Daniele , Macera Lisa , Spezia Pietro Giorgio , Ceccarelli Francesca , Lanza Maria , Maggi Fabrizio
Published: August 2021

Background

Pathogen reduction technologies (PRT) based on nucleic‐acid damaging chemicals and/or irradiation are increasingly being used to increase safety of blood components against emerging pathogens, such as convalescent plasma in the ongoing COVID‐19 pandemic. Current methods for PRT validation are limited by the resources available to the blood component manufacturer, and quality control rely over pathogen spiking and hence invariably require sacrifice of the tested blood units: quantitative real‐time PCR is the current pathogen detection method but, due to the high likelihood of detecting nonviable fragments, requires downstream pathogen culture. We propose here a new molecular validation of PRT based on the highly prevalent human symbiont torquetenovirus (TTV) and rolling circle amplification (RCA).

Materials and methods

Serial apheresis plasma donations were tested for TTV before and after inactivation with Intercept® PRT using real‐time quantitative PCR (conventional validation), RCA followed by real‐time PCR (our validation), and reverse PCR (for cross‐validation).

Results

While only 20% of inactivated units showed significant decrease in TTV viral load using real‐time qPCR, all donations tested with RCA followed by real‐time PCR showed TTV reductions. As further validation, 2 units were additionally tested with reverse PCR, which confirmed absence of entire circular genomes.

Discussion

We have described and validated a conservative and easy‐to‐setup protocol for molecular validation of PRT based on RCA and real‐time PCR for TTV.
WHO ARE THE HUMANITIES FOR? DECOLONIZING THE HUMANITIES
Authors: Stenmark Lisa L.
Published: August 2021

Drees makes a strong case for the importance of the humanities in the university, providing an excellent resource for anyone in the Western Academy. Its usefulness for those who want to work outside the West is limited, however, because he does not engage with literature that challenges its methods and disciplines. If we are to have a positive global impact, we need to do more than clarify existing boundaries, we need to blur them, beginning with an examination of inherent biases reflected in its history, structure, and content. This article focuses on one critique, a decolonial critique of the Western view that ontology precedes epistemology (an external reality produces knowledge). Outside the modern Western Academy, epistemologies create ontologies (epistemic creations/stories about the world give us a sense of the world and its materiality). I describe a relational understanding of knowledge and how this changes our understanding of the humanities and our epistemic responsibilities.
Effects of long‐term immobilisation on endomysium of the soleus muscle in humans
Authors: Thot Georgina K. , Berwanger Carolin , Mulder Edwin , Lee Jessica K. , Lichterfeld Yannick , Ganse Bergita , Giakoumaki Ifigeneia , Degens Hans , Duran Ibrahim , Schönau Eckhard , Clemen Christoph S. , Brachvogel Bent , Rittweger Jörn
Published: August 2021

New Findings

What is the central question of this study?

While muscle fibre atrophy in response to immobilisation has been extensively examined, intramuscular connective tissue, particularly endomysium, has been largely neglected: does endomysium content of the soleus muscle increase during bed rest?

What is the main finding and its importance?

Absolute endomysium content did not change, and previous studies reporting an increase are explicable by muscle fibre atrophy. It must be expected that even a relative connective tissue accumulation will lead to an increase in muscle stiffness.

Muscle fibres atrophy during conditions of disuse. Whilst animal data suggest an increase in endomysium content with disuse, that information is not available for humans. We hypothesised that endomysium content increases during immobilisation. To test this hypothesis, biopsy samples of the soleus muscle obtained from 21 volunteers who underwent 60 days of bed rest were analysed using immunofluorescence‐labelled laminin γ‐1 to delineate individual muscle fibres as well as the endomysium space. The endomysium‐to‐fibre‐area ratio (EFAr, as a percentage) was assessed as a measure related to stiffness, and the endomysium‐to‐fibre‐number ratio (EFNr) was calculated to determine whether any increase in EFAr was absolute, or could be attributed to muscle fibre shrinkage. As expected, we found muscle fibre atrophy (P = 0.0031) that amounted to shrinkage by 16.6% (SD 28.2%) on day 55 of bed rest. ENAr increased on day 55 of bed rest (P < 0.001). However, when analysing EFNr, no effect of bed rest was found (P = 0.62). These results demonstrate that an increase in EFAr is likely to be a direct effect of muscle fibre atrophy. Based on the assumption that the total number of muscle fibres remains unchanged during 55 days of bed rest, this implies that the absolute amount of connective tissue in the soleus muscle remained unchanged. The increased relative endomysium content, however, could be functionally related to an increase in muscle stiffness.
High-Temperature Solid Particle Erosion in a Melt-Infiltrated SiC/SiC Ceramic Matrix Composite
Authors: Presby Michael J.
Published: August 2021

Ceramic matrix composites are an enabling propulsion material system that offer weight benefits over current Ni-based superalloys, and have higher temperature capabilities that can reduce cooling requirements. Incorporating ceramic matrix composites into the hot section of gas-turbine engines therefore leads to an increase in engine efficiency. While significant advancements have been made, challenges still remain for current and next-generation gas turbines; particularly when operating in dust laden or erosive environments. Solid particles entrained in the gas flow can impact engine hardware resulting in localized damage and material removal due to repeated, cumulative impacts. In this study, the erosion behavior of a melt-infiltrated (MI) silicon carbide fiber-reinforced silicon carbide (SiC/SiC) ceramic matrix composite is investigated at high temperature (1200 °C) in a simulated combustion environment using 150 μm alumina particles as erodent. Particle impact velocities ranged from 100 to 200 m/s and the angle of impingement varied from 30 to 90 deg. Erosion testing was also performed on α-SiC to elucidate similarities and differences in the erosion response of the composite compared to that of a monolithic ceramic. Scanning electron microscopy was used to study the posterosion damage morphology and the governing mechanisms of material removal.
Impact of a Centerbody on the Unsteady Flow Dynamics of a Swirl Nozzle: Intermittency of Precessing Vortex Core Oscillations
Authors: Gupta Saarthak , Shanbhogue Santosh , Shimura Masayasu , Ghoniem Ahmed , Hemchandra Santosh
Published: August 2021

The precessing vortex core (PVC) is a self-excited flow oscillation state occurring in swirl nozzles. This is caused by the presence of a marginally unstable hydrodynamic helical mode that induces precession of the vortex breakdown bubble (VBB) around the flow axis. The PVC can impact emissions and thermoacoustic stability characteristics of combustors in various ways, as several prior studies have shown. In this paper, we examine the impact of centerbody diameter (Dc) on the PVC in a nonreacting flow in a single nozzle swirl combustor. Time-resolved high-speed stereoscopic PIV measurements are performed for combinations of two swirl numbers, S = 0.67 and 1.17 and Dc = 9.5 mm, 4.73 mm, and 0 (i.e., no centerbody). The bulk flow velocity at the nozzle exit plane is kept constant as Ub = 8 m/s for all cases (Re∼20,000). The centerbody end face lies in the nozzle exit plane. A new modal decomposition technique based on wavelet filtering and proper orthogonal decomposition provides insight into flow dynamics in terms of global modes extracted from the data. The results show that without a centerbody, a coherent PVC is present in the flow as expected. The introduction of a centerbody makes the PVC oscillations intermittent. These results suggest two routes to intermittency as follows. For S = 0.67, the VBB and centerbody wake recirculation zone regions are nominally distinct. Intermittent separation and merger due to turbulence result in PVC oscillations due to the destabilization of the hydrodynamic VBB precession mode of the flow. In the S = 1.17 case, the time averaged VBB position causes it to engulf the centerbody. In this case, the emergence of intermittent PVC oscillations is a result of the response of the flow to broadband stochastic forcing imposed on the time averaged vorticity field due to turbulence.
A Code for the Preliminary Design of Cooled Supercritical CO2 Turbines and Application to the Allam Cycle
Authors: Scaccabarozzi Roberto , Martelli Emanuele , Pini Matteo , De Servi Carlo Maria , Chiesa Paolo , Gatti Manuele
Published: August 2021

This paper documents a thermo-fluid-dynamic mean-line model for the preliminary design of multistage axial turbines with blade cooling applicable to supercritical CO2 turbines. Given the working fluid and coolant inlet thermodynamic conditions, blade geometry, number of stages and load criterion, the model computes the stage-by-stage design along with the cooling requirement and ultimately provides an estimate of turbine efficiency via a semi-empirical loss model. Different cooling modes are available and can be selected by the user (stand-alone or combination): convective cooling, film cooling, and thermal barrier coating. The model is applied to attain the preliminary aero-thermal design of the 600 MW cooled axial supercritical CO2 turbine of the Allam cycle. Results show that a load coefficient varying from 3 to 1 throughout the machine, and a reaction degree ranging from 0.1 to 0.5 lead to the maximum total-to-static turbine efficiency of about 85%. Consequently, as opposed to uncooled CO2 turbines, a repeated stage configuration is an unsuited design choice for cooled sCO2 machines. Moreover, the study highlights that film cooling is considerably less effective compared to conventional gas turbines, while increasing the number of stages from 5 to 6 and adopting higher rotational speeds leads to an increased efficiency.
Nanoscale Continuous Directional Motion Driven by a Cyclic Thermal Field
Authors: Chen Yichang , Leng Jiantao , Guo Zhengrong , Zhang Yingyan , Chang Tienchong
Published: August 2021

Directional motion plays a crucial role in various mechanical systems. Although mechanisms for nanoscale directional motion have been widely used in many aspects of nanotechnology, it remains a great challenge to generate continuous and controllable motion at the nanoscale. Herein, we propose a nanoscale continuous directional motion in cyclic thermal fields by using a double-walled system which consists of an outer BN/C heterojunction nanotube and a concentric inner carbon nanotube (CNT). By manipulating the heating regions of the outer BN/C heterojunction tube, the continuous motion of the inner CNT can be realized with ease. The inner CNT demonstrates three distinct movements due to the joint actions of the asymmetric thermal gradient forces and interlayer attraction forces caused by the presence of the outer BN/C heterojunction nanotube. The mechanism revealed in the present study may be useful in designing novel devices for energy conversion and directional transportation.
Thermal Analysis and Parametric Investigation of Phase Change Material-Air Cooled Lithium Ion Battery Pack
Authors: Türkakar Göker
Published: August 2021

A parametric analysis has been conducted for the phase change material (PCM)-air cooled battery pack. The system is composed of 26650 lithium-ion LiFePO4 batteries enclosed by PCM. A one-dimensional thermal model for the PCM domain is developed using the enthalpy method. The finite volume method is employed to solve the energy equation for both cell and PCM domain. The developed computational algorithm has been validated as a result of the simulations for the same conditions with the literature. The discharge process of the batteries has been investigated for 2C, 3C, and 5C rates. Thermal analyses have been performed for passive (natural convection) and active cooling (forced convection). It is aimed to keep the temperature of the battery cell under critical levels. A parametric investigation for crucial parameters like PCM layer thickness, the thermal conductivity of the PCM, arrangement of the batteries has been performed. Simulations have been conducted for the constant air velocity and the pumping power. Thanks to the constant pumping power analysis, thermally best-performing configuration have been sought by eliminating the hydrodynamic effect.
A Thermo-Hydraulic Investigation of the Unprecedented TMRS Upper Neutron Spallation Target
Authors: Scheel Matthew , Woloshun Keith , Olivas Eric
Published: August 2021

The next-generation neutron spallation target station, the Target–Moderator-Reflector System (TMRS) Mk. IV, will be installed in 2021. This iteration features an unprecedented, water-cooled, third internal target aptly named the upper target. With the upper target designed completely by analysis, a complementary empirical investigation was undertaken to ascertain target conformance to those computational results which deemed the cooling efficacious. Three facets of the target were designated for verification: displacement under hydraulic load, critical fluid velocities, and the characteristic heat transfer coefficient (HTC). With the potential for flow maldistribution under excessive displacements, static pressure testing was performed. Discrepancies of an order of magnitude became evident between empirical and simulated displacements, 1.499 mm versus 0.203 mm, respectively. A closed-water flow loop reproducing the flow parameters intrinsic to the TMRS Mk. IV was constructed. Utilizing particle image velocimetry, global fluid dynamics were observed to be analogous to computer simulation. Furthermore, crucial velocities such as those at the point of beam impingement were met or exceeded, thus satisfying cooling requirements by a preponderance. A graphite susceptor mirroring nominal beam geometry was coupled to a solenoid coil to replicate a prodigious peak heat flux of 169 W/cm2 via induction heating. Matching peak heat flux within 3% engendered a HTC of 80% that of simulation. Consistent with analysis, the local HTC sufficiently mitigated nucleate/flow boiling. In summary, the analytically derived upper target design empirically demonstrated sufficient cooling despite quixotic beam conditions and unforeseen displacements.
A Novel Test Rig Using Air for Investigation of Vibration and Interaction of Two Steam Turbine Control Valves
Authors: Wallat Stefan , Preibisch Stefan , Strauch Matthias , Brillert Dieter
Published: August 2021

The governing of steam turbines is often realized by a set of two or more valves, which control the amount of steam entering the turbine. During part-load operation forces caused by pressure fluctuations and turbulence are acting on the throttling valve and lead to spindle vibrations. Besides these mechanisms, it is assumed that there is also an interaction between the control valves, which leads to another source of vibration. In this paper, the design of a new test rig using air with two parallel control valves is presented. One aspect of the design is the chosen scaling method, which includes a material selection for the valve spindle, and ensures comparability and transferability of the vibrational behavior to the full scale with steam. Another aspect is the selection of measurement equipment. The results show that the reasons for valve vibrations can be located both upstream and downstream of the valve seat. Forces caused by pressure fluctuations in and behind the valve gap lead to similar oscillations at both valves. In addition, the upstream valve causes disturbances that lead to partly differing behavior of the second valve.
Associations Between Perceived Neighborhood Walkability and Device-Based Physical Activity and Sedentary Behavior Patterns in Older Adults
Authors: Greenwood-Hickman Mikael Anne , Walker Rod , Bellettiere John , LaCroix Andrea Z. , Kim Boeun , Wing David , Richmire KatieRose , Crane Paul K. , Larson Eric B. , Rosenberg Dori E.
Published: August 2021

Neighborhood walkability has been associated with self-reported sedentary behavior (SB) and self-reported and objective physical activity. However, self-reported measures of SB are inaccurate and can lead to biased estimates, and few studies have examined how associations differ by gender and age. The authors examined the relationships between perceived neighborhood walkability measured with the Physical Activity Neighborhood Environment Scale (scored 1.0–4.0) and device-based SB and physical activity in a cohort of community-dwelling older adults (N = 1,077). The authors fit linear regression models adjusting for device wear time, demographics, self-rated health, and accounting for probability of participation. The Higher Physical Activity Neighborhood Environment Scale was associated with higher steps (+676 steps/point on the Physical Activity Neighborhood Environment Scale, p = .001) and sit-to-stand transitions (+2.4 transitions/point, p = .018). Though not statistically significant, stratified analyses suggest an attenuation of effect for those aged 85 years and older and for women. Consistent with previous literature, neighborhood walkability was associated with more steps, though not with physical activity time. The neighborhood environment may also influence SB.
Impact of Social Isolation on Physical Activity and Factors Associated With Sedentary Behavior in Older Adults During the COVID-19 Pandemic
Authors: Mazo Giovana Z. , Fank Felipe , Franco Pedro S. , Capanema Bruna da Silva Vieira , Pereira Franciele da Silva
Published: August 2021

The objective was to analyze the impact of social isolation on moderate physical activity and factors associated with sedentary behavior of older adults during the COVID-19 pandemic. This was a cross-sectional study involving 111 older adults (aged 71.0 ± 6.87 years). The data were collected at two time points: in November 2019 and in June 2020. There was a decline in moderate physical activity when the minutes/week were compared before and during social isolation (p < .001). Sedentary behavior was associated with the condition of living alone. Older adults who lived alone were 3.29 times more likely to spend 4 hr or more in sedentary behavior than those who lived with a partner (95% confidence interval [1.01, 10.74]). Government agencies must establish PA-related health promotion strategies, especially in developing and low-income countries. Therefore, home exercises need to be encouraged to prevent the consequences of this pandemic period.
Efferocytosis fuels malignant pleural effusion through TIMP1
Authors: Zhao Lilan , Giannou Anastasios D. , Xu Yang , Shiri Ahmad Mustafa , Liebold Imke , Steglich Babett , Bedke Tanja , Zhang Tao , Lücke Jöran , Scognamiglio Pasquale , Kempski Jan , Woestemeier Anna , Chen Jing , Agalioti Theodora , Zazara Dimitra E. , Lindner Diana , Janning Melanie , Hennigs Jan K. , Jagirdar Rajesh M. , Kotsiou Ourania S. , Zarogiannis Sotirios G. , Kobayashi Yasushi , Izbicki Jacob R. , Ghosh Sourav , Rothlin Carla V. , Bosurgi Lidia , Huber Samuel , Gagliani Nicola
Published: August 2021

The clearance of apoptotic cells by Mφs favors malignant pleural effusion progression in a murine cancer model.
A cyanosulfidic origin of the Krebs cycle
Authors: Ritson Dougal J.
Published: August 2021

All four cellular subsystems can be provided under compatible prebiotic conditions.
Excess of COVID-19 cases and deaths due to fine particulate matter exposure during the 2020 wildfires in the United States
Authors: Zhou Xiaodan , Josey Kevin , Kamareddine Leila , Caine Miah C. , Liu Tianjia , Mickley Loretta J. , Cooper Matthew , Dominici Francesca
Published: August 2021

High levels of PM
2.5
during the 2020 wildfires in the western United States led to an excess of COVID-19 cases and deaths.
Acute Q fever in third trimester pregnancy
Authors: Braddick Maxwell , Woods Marion L , Prabhaharan Suji
Published: August 2021

A 29-year-old gravida 2 para 1 woman presented at 29 weeks gestation with fevers, back pain, thrombocytopenia and hepatitis. PCR testing of blood samples detectedCoxiella burnetiiand paired serology later confirmed the diagnosis of acute Q fever in pregnancy. The patient was treated empirically with oral clarithromycin and experienced a symptomatic and biochemical improvement. Therapy was changed to oral trimethoprim/sulphamethoxazole but was complicated by a delayed cutaneous reaction, prompting recommencement of clarithromycin. Therapy continued until delivery of a healthy girl at 39 weeks and 3 days. Q fever in pregnancy is likely under-reported and is associated with the development of chronic infection and obstetric complications. Treatment with clarithromycin is an alternative to trimethoprim/sulphamethoxazole in the setting of drug intolerance.
Autoimmune atrophic gastritis in systemic sclerosis
Authors: Avasthi Deepti , Thomas Jean , Miriyala Leela Krishna Vamsee , Avasthi Salil
Published: August 2021

Systemic sclerosis (SSc) is a rare connective tissue disorder with a complex pathogenesis involving vascular dysfunction, small vessel proliferation as well as alterations of innate and adaptive immunity. Gastrointestinal (GI) involvement in SSc is almost universal and affects nearly 90% of the patients. Of all the GI manifestations, 30%–75% are oesophageal abnormalities, including gastro-oesophageal reflux disease, reflux oesophagitis and Barret’s oesophagus. The incidence of gastric manifestations is about 22% with a common presentation of gastric antral vascular ectasia (GAVE). However, autoimmune atrophic gastritis (AIG) is not a known manifestation of SSc. Our case has a unique presentation of the coexistence of GAVE and AIG. We have conducted a thorough literature review to study a possible association of AIG and SSc and understand the pathology of SSc.
Isolated hepatosplenic tuberculosis: a rare presentation with persistent fever in a 2-year-old female child
Authors: Tharakan Riya , John Sujonitha , Devdas Jaidev Mangalore , Hegde Pavan
Published: August 2021

A 2-year-old female child from South India presented with persistent fever for 3 weeks, pallor and hepatosplenomegaly. There was no history of contact with tuberculosis (TB) and BCG scar was absent. Tests for TB (Mantoux and gastric aspirate) were negative. Blood and bone marrow tests for other infections, inflammation and infiltration were inconclusive. Chest X-ray was normal. Ultrasound study (USS) of abdomen showed multiple microabscesses in the liver and spleen. USS-guided fine needle aspiration cytology from splenic lesion demonstrated epithelioid granuloma while bacteriology was negative. Commencement of anti-tubercular therapy (ATT) resulted in remarkable clinical improvement in a week with resolution of lesions on follow-up USS in 2 months. Isolated hepatosplenic TB in children, though rare, has a wide, non-specific clinical spectrum and potential of delaying diagnosis. Probability diagnosis and therapeutic trials of ATT are accepted approaches, using treatment response as indirect confirmation of the likely cause.
Atypical presentation of catastophric spontaneous mesenteric bleeding
Authors: Ohn May Honey , Ng Jun Rong , Luen Ng Pey , Ohn Khin Maung
Published: August 2021

Spontaneous mesenteric bleeding is an exceptionally rare clinical condition and potentially lethal especially among elderly patients who are taking oral anticoagulant. We present a case of a 79-year-old woman who presented to the emergency department with atypical chest pain which was radiating to the back. She developed profound hypotension with a sudden drop of haemoglobin. Contrast-enhanced CT of the aorta showed active mesenteric bleeding with mesenteric haematoma. The early diagnosis relies solely on a high index of suspicion of occult bleeding in patients with unexplained hypotension with a sudden drop of haemoglobin. Troponin can be falsely positive in mesenteric bleeding. Close monitoring to detect any sign of deterioration and early imaging in diagnosing intra-abdominal bleeding can help to avoid delay in treatment which is essential to prevent mortality and morbidity.