bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk factors for difficult‐to‐treat hepatitis C virus genotype 4r in Rwanda and implications for elimination in sub‐Saharan Africa
Authors: Shumbusho Fabienne , Liu Anne F. , Kateera Fredrick , Kabahizi Jules , Nsanzaimana Sabin , Serumondo Janvier , Damascene Makuza Jean , Grant Philip M. , Musabeyezu Emmanuel , Muvunyi Claude , Gupta Neil
Published: January 2021

In sub‐Saharan Africa, there exist distinct HCV genotype (GT) subtypes harbouring resistance‐associated substitutions to commonly used non‐structural protein 5A (NS5A) inhibitor–based direct‐acting antiviral (DAA) regimens. In particular, GT4r subtype has demonstrated high rates of treatment failure. In the absence of routine viral sequencing in sub‐Saharan Africa, it is important to identify sociodemographic, epidemiologic, and clinical characteristics that may be associated with GT4r infection. Methods: A secondary analysis was performed on data from 300 adults with HCV GT4 enrolled in a prospective trial assessing the safety and efficacy of sofosbuvir‐ledipasvir in Rwanda in 2017. The association between characteristics at enrolment and GT subtype was assessed by chi‐square analysis and logistic regression. In multivariate analysis, there were a higher proportion of participants with GT4r subtype with age <40 years (OR: 3.6, 95% CI: 1.3–10.5, p = 0.02), previous hospitalization (OR: 2.5, 95% CI: 1.3–5.0, p = 0.006), previous surgery (OR: 2.2, 95% CI: 1.1–4.2, p = 0.03), cirrhosis (OR: 3.2, 95% CI: 1.3–7.5, p = 0.008) and baseline HCV RNA >1 million IU/ml (OR: 3.4, 95% CI: 1.6–6.9, p = 0.001). Rwandan adults with GT4r are more likely to be younger, have a history of hospital admissions and surgeries and have more active or advanced liver disease compared to those with other GT4 subtypes. In the absence of advanced diagnostics to assess GT subtype, patients with these characteristics may warrant closer monitoring for treatment failure or alternative DAA regimens. More treatment experience with diverse DAA regimens is urgently needed for GT subtypes particular to this region.
Visualization of brain microvasculature and blood flow in vivo: Feasibility study using confocal laser endomicroscopy
Authors: Belykh Evgenii , Zhao Xiaochun , Ngo Brandon , Farhadi Dara S. , Kindelin Adam , Ahmad Saif , Martirosyan Nikolay L. , Lawton Michael T. , Preul Mark C.
Published: January 2021

Objective

Qualitative and quantitative analyses of blood flow in normal and pathologic brain and spinal cord microvasculature were performed using confocal laser endomicroscopy (CLE).

Methods

Blood flow in cortical, dural, and spinal cord microvasculature was assessed in vivo in swine. We assessed microvasculature under normal conditions and after vessel occlusion, brain injury due to cold or surgical trauma, and cardiac arrest. Tumor‐associated microvasculature was assessed in vivo and ex vivo in 20 patients with gliomas.

Results

We observed erythrocyte flow in vessels 5‐500 µm in diameter. Thrombosis, flow arrest and redistribution, flow velocity changes, agglutination, and cells rolling were assessed in normal and injured brain tissue. Microvasculature in in vivo CLE images of gliomas was classified as normal in 68% and abnormal in 32% of vessels on the basis of morphological appearance. Dural lymphatic channels were discriminated from blood vessels. Microvasculature CLE imaging was possible for up to 30 minutes after a 1 mg/kg intravenous dose of fluorescein.

Conclusions

CLE imaging allows assessment of cerebral and tumor microvasculature and blood flow alterations with subcellular resolution intraoperative imaging demonstrating precise details of real‐time cell movements. Research and clinical scenarios may benefit from this novel intraoperative in vivo microscopic fluorescence imaging modality.
Novel Design of the Chimeric Deep Inferior Epigastric Artery Perforator Flap that Provides for Three‐Dimensional Reconstruction of Composite Tissue Defects of the Heel in Children
Authors: Yu Junyi , Luo Zhenhua , Wu Panfeng , Tang Juyu
Published: January 2021

Objective

The aim of the present study was to report a novel design of the chimeric deep inferior epigastric artery perforator flap (DIEP) to achieve dead space filling, Achilles tendon bridging, and skin resurfacing simultaneously with minimal donor‐site morbidity.

Methods

From September 2012 to May 2016, a retrospective study was carried out on six pediatric patients with composite soft tissue defects of the heel that were repaired with the chimeric DIEP flap. The chimeric flap design included a flap of the anterior sheath of the rectus, a block of rectus muscle, and a large skin paddle. All the parts were supplied by a common artery. After harvesting the flap, all element parts were inserted at the corresponding sites in a tension‐free manner. With one set of vessel anastomoses at the recipient site, accurate repair with tendon reconstruction, dead space elimination, and wound covering were accomplished. The donor site incisions were closed initially. Data on patient age, medical history, injury severity, defect size, flap dimensions, recipient vessels, donor site closure, complications, and follow‐up were collected and reviewed.

Results

Five of the six chimeric DIEP flaps survived without complications. The remaining one case experienced partial necrosis of the skin paddle caused by venous congestion, which healed after routine dressing changes. Primary donor site closure was accomplished in all cases. The mean follow‐up was 18.6 months (range, 10–36 months). Five patients had satisfactory aesthetic and functional outcomes; one patient needed a secondary debulking procedure. Compared to the unaffected side, the affected side showed no obvious difference for ankle movement, tiptoe function, and patient gait during the follow‐up period. Good ankle function was observed in all patients. There was no donor site breakdown, with only a slightly noticeable linear scar.

Conclusion

The chimeric DIEP flap reduced the operative time, solved the problem of deficiency of recipient vessels, and attained satisfactory functional and aesthetic outcomes with low donor site morbidity. Therefore, it is a promising option for three‐dimensional reconstruction of composite defects with dead space and Achilles tendon defects as well as skin loss in children.
Risk‐Stratified Venous Thromboembolism Prophylaxis after Total Joint Arthroplasty: Low Molecular Weight Heparins and Sequential Aspirin vs Aggressive Chemoprophylaxis
Authors: Peng Hui‐ming , Chen Xi , Wang Yi‐ou , Bian Yan‐yan , Feng Bin , Wang Wei , Weng Xi‐sheng , Qian Wen‐wei
Published: January 2021

Objective

Venous thromboembolism (VTE) is a significant concern post total joint arthroplasty (TJA). However, the optimal prevention method of VTE remains controversial at present. This study aims to evaluate a risk‐stratified VTE prophylaxis protocol for patients undergoing TJA.

Methods

A total of 891 TJA patients from January 2011 to November 2019 were retrospectively investigated. The study was divided into two cohorts. In cohort 1, 410 patients (250 females and 160 males, mean age 64.32 years) were treated with an aggressive VTE chemoprophylaxis protocol. In cohort 2, 481 patients were treated with a risk‐stratified protocol that utilized low molecular weight heparins (LMWH) and sequential aspirin (ASA) for standard‐risk patients (a total of 288 containing 177 females and 111 males, mean age 65.4 years), and targeted anticoagulation for high‐risk patients (a total of 193 containing 121 females and 72 males, mean age 66.8 years). The patients were followed up at 2–4 weeks for an initial visit and at 6–10 weeks for a subsequent visit after surgery. A chart review of all patient medical records was performed to record the demographics, comorbidities, deep vein thrombosis, pulmonary embolus, superficial infection, deep infection, bleeding complications, and 90‐day readmissions.

Results

The VTE rate was 1.71% (7/410) in cohort 1 and 1.46% (7/481) in cohort 2 respectively. For cohort 2, the VTE rate was 2.07% (4/193) in high‐risk group and 1.04% (3/288) in standard‐risk group. The readmission rate was 2.44% (10/410) in cohort 1 and 2.08% (10/481) in cohort 2. For cohort 2, the readmission rate was 2.07% (4/193) in high‐risk group and 2.08% (6/288) in standard‐risk group. The reasons for readmission were as follows: infection, 1.3% (5/410) in cohort 1 and 1.3% (6/481) in cohort 2; wound or bleeding complications, 0.48% (2/410) in cohort 1 and 0.2% (1/481) in cohort 2; trauma, 0.2% (1/410) in cohort 1 and 0.2% (1/481) in cohort 2; VTE, 0.2% (1/410) in cohort 1 and 0.2% (1/481) in cohort 2; others, 0.2% (1/410) in cohort 1 and 0.6% (3/481) in cohort 2. There was a decrease in VTE events and readmissions in the risk‐stratified cohort, although this did not reach statistical significance. However, it was found that there was a significant reduction in costs (P < 0.001) with the use of LMWH/ASA, when compared with aggressive anticoagulation agents in the risk‐stratified cohort.

Conclusion

The use of LMWH/ASA in a risk‐stratified TJA population is a safe and cost‐effective method of VTE prophylaxis.
Guide for diagnosis and treatment of hyperphenylalaninemia
Authors: Shintaku Haruo , Ohura Toshihiro , Takayanagi Masaki , Kure Shigeo , Owada Misao , Matsubara Yoichi , Yoshino Makoto , Okano Yoshiyuki , Ito Tetsuya , Okuyama Torayuki , Nakamura Kimitoshi , Matuo Masafumi , Endo Fumio , Ida Hiroyuki
Published: January 2021

Importance

Sapropterin hydrochloride, a natural coenzyme (6R‐tetrahydrobiopterin) of phenylalanine hydroxylase, was first approved as a treatment for tetrahydrobiopterin deficiency in 1992 in Japan, and was then approved as a treatment for a tetrahydrobiopterin‐responsive hyperphenylalaninemia in 2007 and 2008, in the USA and Japan, respectively. Guidelines are required on the proper use of sapropterin hydrochloride for tetrahydrobiopterin‐responsive hyperphenylalaninemia.

Observations

It is recommended that tetrahydrobiopterin‐responsive hyperphenylalaninemia should be diagnosed in all cases of hyperphenylalaninemia, including phenylketonuria, by tetrahydrobiopterin administration tests rather than by phenotype or blood phenylalanine levels.

Conclusions and Relevance

If tetrahydrobiopterin‐responsive hyperphenylalaninemia is diagnosed, all ages can be treated with sapropterin hydrochloride. Although there are reports that sapropterin hydrochloride is effective and safe for the prevention of maternal phenylketonuria, further investigation is required.
Implication of actin in the uptake of sucrose and valine in the tap root and leaf of sugar beet
Authors: Michonneau Philippe , Fleurat‐Lessard Pierrette , Cantereau Anne , Crépin Alexandre , Roblin Gabriel , Berjeaud Jean‐Marc
Published: January 2021

Actin microfilaments (F‐actin) are major components of the cytoskeleton essential for many cellular dynamic processes (vesicle trafficking, cytoplasmic streaming, organelle movements). The aim of this study was to examine whether cortical actin microfilaments might be implicated in the regulation of nutrient uptake in root and leaf cells of Beta vulgaris. Using antibodies raised against actin and the AtSUC1 sucrose transporter, immunochemical assays demonstrated that the expression of actin and a sucrose transporter showed different characteristics, when detected on plasma membrane vesicles (PMVs) purified from roots and from leaves. The in situ immunolabeling of actin and AtSUC1 sites in PMVs and tissues showed their close proximity to the plasma membrane. Using co‐labeling in protoplasts, actin and sucrose transporters were localized along the internal border and in the outermost part of the plasma membrane, respectively. This respective membrane co‐localization was confirmed on PMVs and in tissues using transmission electronic microscopy. The possible functional role of actin in sucrose uptake (and valine uptake, comparatively) by PMVs and tissues from roots and leaves was examined using the pharmacological inhibitors, cytochalasin B (CB), cytochalasin D (CD), and phalloidin (PH). CB and CD inhibited the sucrose and valine uptake by root tissues in a concentration‐dependent manner above 1 μM, whereas PH had no such effect. Comparatively, the toxins inhibited the sucrose and valine uptake in leaf discs to a lesser extent. The inhibition was not due to a hindering of the proton pumping and H+‐ATPase catalytic activity determined in PMVs incubated in presence of these toxins.
MicroRNA regulation of viral replication in teleost fish: a review
Authors: Zhang Chi , Tu Jiagang , Zhang Yong‐An
Published: January 2021

MicroRNAs (miRNAs) are single‐stranded non‐coding RNA molecules. In addition to participating in various biological processes of eukaryotes, such as cell proliferation, development, differentiation, metabolism, tumorigenesis, and apoptosis, miRNAs also play an important role in the regulation of virus replication. Here, we review the current knowledge on high‐throughput miRNA sequencing of teleost fish or fish cells in response to virus infection, the role of teleost fish miRNAs in regulating virus replication via targeting either fish or virus genes and the function of teleost fish virus‐encoded miRNAs during virus infection. Understanding the interaction between the miRNAs and the host or virus genes will lead to the identification of novel strategy to prevent virus infection in teleost fish.
Russia's Queer Science, or How Anti‐LGBT Scholarship is Made
Authors: MOSS KEVIN
Published: January 2021

The absence of a politicized gay community and of any real scholarly consensus about sexuality in Russia has made it possible for new “scholars” to advance theories of sexuality that are very much at odds with those that are accepted in Europe and the United States. Much mainstream Russian scholarship on queer topics from the Russian Academy of Sciences and the Sociology Faculty of Moscow State University is highly ideological and based on the universalizing concept that everyone can become lesbian or gay. This paper analyzes several articles written between 2012 and 2014 by prominent Russian sources to show how they confuse concepts basic to queer theory and gender studies (gender/sex/sexual orientation/gender identity), while repeating accounts from right‐wing conservative and anti‐LGBT activists and discredited scholars from the United States. The few Russian scholars who are integrated into international gender studies and queer scholarship tend to be marginalized, while more established senior scholars at important institutions tend to be ideological and anti‐LGBT. This situation has facilitated the adoption of anti‐LGBT laws in Russia, and some of these scholars participate in global right‐wing anti‐gender and anti‐LGBT networks like the World Congress of Families.
Sexual Citizens in Exile: State‐Sponsored Homophobia and Post‐Soviet LGBTQI+ Migration
Authors: NOVITSKAYA ALEXANDRA
Published: January 2021

This article presents a transnational ethnography of a Russian‐speaking LGBTQ (lesbian, gay, bisexual, transgender and queer/questioning) community in New York City addressing the impact of state‐sponsored homophobia in Russia, particularly the 2013 “gay propaganda” ban on international queer migration. Drawing on the theorizations of Russian state‐sponsored homophobia from a perspective of sexual citizenship, the article suggests that emigration through political asylum becomes a new form of the post‐Soviet queer political subject's response to the exclusion from citizenship. Accompanied by the increase in physical and symbolic violence generated by the antigay legislation, the current configuration of sexual citizenship makes staying in Russia unbearable for some non‐heterosexual citizens prompting them to emigrate. In the United States, they attempt to find safety from systemic homophobia and access sexual citizenship rights by applying for political asylum, which is a precarious route in itself as it makes them vulnerable to the structural violence of the U.S. immigration regime. Their willingness to take this risk indicates the significance of both state‐sponsored homophobia and sexual citizenship to their lives. The article also considers another transnational effect of the “gay propaganda” law: the transformation of RUSA LBGT, a New‐York‐City‐based Russian‐speaking LGBTQ community, from a social to activist organization, due to the influx of new migrants seeking asylum in the United States. Thus, it suggests that state‐sponsored homophobia in Russia has de‐territorialized transnational effects such as stimulation of LGBTQ emigration and transformation and mobilization of diasporic communities.
“La Crème de la Crème”: How Racial, Gendered, and Intersectional Social Comparisons Reveal Inequities That Affect Sense of Belonging in STEM
Authors: Brockman Amanda J.
Published: January 2021

This paper analyses the social‐psychological processes of social comparison and relative deprivation with regard to race, gender, and their intersections in STEM higher education through the narratives of 33 Black respondents who described their experiences within engineering and computer science doctoral programs. I use social comparison and relative deprivation, a subsidiary theory of social comparison, as guiding theoretical frameworks. Since the intersections of race and gender are salient, I also incorporate an intersectional framework as an analytical tool. Through data derived from semi‐structured interviews, I find that, when describing graduate‐school experiences, Black engineering and computer science respondents use social comparisons with regard to race, gender, and their intersections to juxtapose their experiences with those of their peers. Participants described feeling relatively deprived due to inequities resulting from racism and/or sexism and primarily felt that STEM privileged students that were Asian men. Nevertheless, Black men described downward social comparisons with their Black female counterparts, recognizing the sexist culture of STEM. Overall, however, social comparison processes led Black respondents to identify inequities within their Ph.D. programs in engineering and computer science that made them feel as though STEM was not intended for them, but, rather, for their Asian and white male peers who are positioned as belonging.
Inequalities and poverty risks in old age across Europe: The double‐edged income effect of pension systems
Authors: Ebbinghaus Bernhard
Published: January 2021

While the sustainability of pension systems facing demographic ageing has been widely discussed, the adequacy of retirement income has often been neglected in current debate. However, considerable poverty and income inequality in old age exists across Europe. Using recent EU‐SILC data (2017/18), the comparative analysis of poverty rates and income inequality in old age shows important cross‐national variations that need to be seen in context of market‐related inequalities but also the specific pension system. Beveridge basic security is not always capable of effectively reducing poverty despite the explicit goal to do so. In addition, private funded pensions may generate social inequality. Some contributory Bismarckian systems are better suited to reduce poverty, but given their focus on status maintenance also reproduce inequality. Poverty rates are low due to encompassing basic pensions in Dutch and some Nordic multipillar systems and in core Central and Eastern European countries. Bismarckian pensions such as in Germany are generating some inequality and medium level of poverty, while France and some Southern European countries perform better on poverty but reproduce larger inequalities. Beveridge systems such as in the United Kingdom and Switzerland with rather meagre basic multipillar systems have relatively medium to high poverty risks. In addition, the Baltic countries and new EU member states in the periphery have the highest poverty rates across Europe. The analysis shows that the minimum income provision of public pension systems matters most for poverty risks, while the overall pension architecture has an impact on reproducing inequality in old age acquired during working life.
An integrated‐likelihood‐ratio confidence interval for a proportion based on underreported and infallible data
Authors: Wiley Briceön , Elrod Chris , Young Phil D. , Young Dean M.
Published: January 2021

We derive and examine the interval width and coverage properties of an integrated‐likelihood‐ratio confidence interval for the binomial parameter p using a double‐sampling scheme. The data consist of a relatively large fallible sample containing underreported data and a relatively small infallible subsample. Via Monte Carlo simulations, we determine that the new integrated‐likelihood‐ratio interval estimator displays slightly conservative to moderately conservative coverage properties for small to medium sample sizes and can have shorter average‐interval width than two previously proposed confidence intervals when p < 0.10 or p > 0.90. We also apply the integrated‐likelihood‐ratio confidence interval to a real‐data set and determine that the integrated‐likelihood‐ratio interval has superior performance when contrasted to two properties of two competing confidence intervals.
Rank atmospheres: The more‐than‐human scentspace and aesthetic of a pigdogging hunt
Authors: Keil Paul G.
Published: January 2021

Pigdogging is a popular pastime in Australia, a form of recreational hunting whereby people collaborate with dogs to chase and catch wild pigs. This paper analyses the hunt as an interspecies event that unfolds through the sensual and sensory entanglements of human and nonhuman, with a particular focus on the perspectives of the hunters. The concept of ‘atmosphere’ will be employed to frame an ethnographic analysis of two facets of pigdogging. First, by hunting with a dog, humans augment their capacity to identify the presence of pigs through the canine's extraordinary sense of scent. Through this relationship, the world of scent is revealed as having atmospheric properties: an enveloping phenomenon which is known through the dog, yet also escapes the hunter's perceptual apprehension. Second, this paper will illustrate examples of how atmosphere develops through the sensual relations between human and nonhuman bodies during the hunt. An affectively charged interspecies encounter is composed and participated in by the hunter through this recreational practice, and affords the enactment of subjectivities central to an aesthetics of pigdogging. Hunting atmospheres in this paper emerge at the juncture of human and more‐than‐human bodies, perspectives and worlds.
Usefulness of PCR for Trypanosoma cruzi DNA in blood and endomyocardial biopsies for detection of Chagas disease reactivation after heart transplantation: A comparative study
Authors: Benvenuti Luiz A. , Freitas Vera L. T. , Roggério Alessandra , Nishiya Anna S. , Mangini Sandrigo , Strabelli Tânia M. V.
Published: January 2021

Background

Chagas disease reactivation (CDR) after heart transplantation is characterized by relapse of the infectious disease with proliferation and dissemination of Trypanosoma cruzi parasites. Serial blood PCR testing is consensually recommended for CDR monitoring, but there is uncertainty about the incremental value in performing the molecular tests in endomyocardial biopsies (EMB).

Methods

We compared qualitative and quantitative results of PCR for T cruzi DNA in 62 pairs of blood and EMB collected with a maximum time interval of 7 days, from 34 heart‐transplanted, chagasic patients.

Results

Blood PCR resulted positive in 39/62 (62.9%) samples, with PL ranging from 0.14 to 1610.73 (median: 3.31). PCR resulted positive in 8/60 (13.3%) EMB, with PL ranging from 2.82 to 1670.55 (median: 65.63). All blood samples which tested negative presented a paired EMB which also tested negative. However, 31/39 (79.5%) blood samples which tested positive presented a paired EMB which tested negative. There was poor agreement between blood and EMB PCR (kappa = 0.153). CDR affecting the myocardium (myo‐CDR) was diagnosed in three occasions. PCR resulted positive in both blood and EMB at the time of myo‐CDR, with PL ranging from 0.61 to 1610.73 in blood and 13.8 to 1670.55 in EMB.

Conclusions

Negative PCR for T cruzi in blood rules out myo‐CDR, with no value of testing EMB. Positive PCR in blood with high PL is diagnostic for myo‐CDR. If PCR in blood results positive with low PL, testing EMB is useful: negative PCR turns unlikely, and positive PCR reinforces greatly the possibility of myo‐CDR.
The impact of the sample time of secondary bacterial culture on the risk of exposure to contaminated platelet components: A mathematical analysis
Authors: Moore Ryleigh A. , Schmidt Robert L. , Metcalf Ryan A.
Published: January 2021

Background

The US Food and Drug Administration (FDA) issued a guidance for bacterial risk control strategies for platelet components in September 2019 that includes strategies using secondary bacterial culture (SBC). While an SBC likely increases safety, the optimal timing of the SBC is unknown. Our aim was to develop a model to provide insight into the best time for SBC sampling.

Study Design and Methods

We developed a mathematical model based on the conditional probability of a bacterial contamination event. The model evaluates the impact of secondary culture sampling time over a range of bacterial contamination scenarios (lag and doubling times), with the primary outcome being the optimal secondary sampling time and the associated risk.

Results

Residual risk of exposure decreased with increasing inoculum size, later sampling times for primary culture, and using higher thresholds of exposure (in colony‐forming units per milliliter). Given a level of exposure, the optimal sampling time for secondary culture depended on the timing of primary culture and on the expiration time. In general, the optimal sampling time for secondary culture was approximately halfway between the time of primary culture and the expiration time.

Conclusion

Our model supports that the FDA guidance is quite reasonable and that sampling earlier in the specified secondary culture windows may be most optimal for safety.
Neutralizing activity to SARS‐CoV‐2 of convalescent and control plasma used in a randomized controlled trial
Authors: Freedenberg Alex T. , Pan Chun‐Hao , Diehl William E. , Romeiser Jamie L. , Hwang Ga‐Ram , Leiton Cindy V. , Muecksch Frauke , Shroyer Kenneth R. , Bennett‐Guerrero Elliott
Published: January 2021

Background

There are limited data on the neutralizing activity of convalescent plasma (CP) administered in randomized controlled trials (RCT) of COVID‐19 infection.

Study Design and Methods

As part of an RCT, CP was collected per FDA guidelines from individuals recovered from COVID‐19 infection. CP donors had to have ≥145 optical density (OD) units (ideal target ≥300) using a semiquantitative, immunochromatographic test for IgG antibody to the nucleocapsid protein (NP) of SARS‐CoV‐2 (typical range 0–500 OD units). A random subset of samples [14 control plasma, 12 CP “medium‐anti‐NP” (145–299 OD units), and 13 CP “high” anti‐NP (≥300 OD units)] were tested for neutralizing antibodies using an established viral luciferase antibody inhibition assay to detect the infection of SARS‐CoV‐2 pseudovirus that encoded spike protein (SARS2‐Strunc) on a human immunodeficiency virus 1 vector (NL43dEnvNanoLuc), using ACE2‐expressing 293 T cells. The titer needed to neutralize 50% of viral activity (NT50) was calculated.

Results

The uptake of SARS‐CoV‐2 pseudovirus by 293TACE2 cells was inhibited by pretreatment with CP compared to control CP (p < .001) with control plasma having a median (IQR) 50% neutralization titer (NT50) of 1:28 (1:16,1:36) compared to 1:334 (1:130,1:1295) and 1:324 (1:244,1:578), for medium anti‐NP and high anti‐NP CP units, respectively. The neutralizing activity of CP met minimum FDA criteria with neutralizing antibody titers >1:80 in 100% of randomly selected samples, using a conservative approach that excluded non‐specific binding.

Discussion

Plasma from donors screened using an immunochromatographic test for IgG antibody to SARS‐CoV‐2 NP exhibited neutralizing activity meeting FDA's minimum standard in all randomly selected COVID‐19 CP units.
Cutaneous and systemic granulomatous disease associated with hairy vetch toxicosis in a French Holstein dairy herd
Authors: Plassard Vincent , Briand Amaury , Laloy Eve , Gourreau Jean‐Marie , Pin Didier , Millemann Yves
Published: January 2021

This report describes an outbreak of hairy vetch toxicosis afflicting a herd of cattle with a fatal cutaneous and systemic granulomatous disease. It highlights how this condition remains poorly recognized by cattle production professionals in Europe and the need for communication about vetch‐associated diseases.
Ground Sea
Authors: Van Gelder Hilde
Published: January 2021

Imagine a world in which each individual has a fundamental right to be reborn. This idle dream haunts Hilde Van Gelder’s associative travelogue that takes Allan Sekula’s sequence Deep Six / Passer au bleu (1996/1998) as a touchstone for a dialogue with more recent artworks zooming in on the borderscape near the Channel Tunnel, such as those by Sylvain George and Bruno Serralongue. Combining ethnography, visual materials, political philosophy, cultural geography, and critical analysis, Ground Sea proceeds through an innovative methodological approach. Inspired by the meandering writings of W.G. Sebald, Javier Marías, and Roland Barthes, Van Gelder develops a style both interdisciplinary and personal. Resolutely opting for an aquatic perspective, Ground Sea offers a powerful meditation on the indifference of an increasingly divided European Union with regard to considerable numbers of persons on the move, who find themselves stranded close to Calais. The contested Strait of Dover becomes a microcosm where our present global challenges of migration, climate change, human rights, and neoliberal surveillance technology converge.
Design and Evaluation of Generic Bump for Flow Control in a Supersonic Inlet Isolator
Authors: Khan Md. Raihan Ali , Hasan A. B. M. Toufique
Published: January 2021

In this paper, the geometry of a supersonic inlet isolator is modified by the introduction of a two-dimensional (2D) bump to control the complex lip shock wave/boundary layer interaction (SWBLI). The bump is of general shape whose profile is designed primarily based on the inviscid theory of oblique shock waves, which accommodates the effect of freestream conditions; particularly, the flow Mach number. Further, the geometric constraints of the inlet are taken into consideration to generate a contoured bump. This well-designed generic bump is tested in the range of flight Mach number of 2.5 to 3.8 through numerical computations. The adopted computational methods are validated with the available experimental data. Results showed that the modified inlet using the present generic bump changes the internal shock structure, weakens the intensity of SWBLI, and subsequently reduces shock reflection phenomena which are prevalent in baseline inlet. The wall characteristics such as separation bubble (SB), skin friction, and total pressure loss are found to be reduced in inlet with bump. The SB in baseline inlet typically corresponds with the geometric profile of the bump. As a result, ramp of baseline inlet is apparently replaced by this generic bump, which eliminates the low momentum fluid adjacent to the wall and the passage of modified inlet is found to be mostly occupied by high momentum supersonic flow. The flow control and associated performance improvement are linked with this modification of supersonic inlet isolator.
Study on the Reduction of the Resonant Stress of Turbine Blades Caused by the Stage Interaction Force (Simultaneous Optimization of Blade Resonant Stress and Amount of Unbalance)
Authors: Kaneko Yasutomo , Watanabe Toshio , Furukawa Tatsuya
Published: January 2021

Although the bladed disks of turbomachinery are nominally designed to be cyclically symmetric (tuned system), the vibration characteristics of individual blades on a disk vary slightly owing to manufacturing tolerances, deviations in material properties, wear during operation, etc. These small variations break the cyclic symmetry and split eigenvalue pairs. Actual bladed disks with small variations are called mistuned systems. The resonant stress on a mistuned bladed disk may become large and cause a blade failure due to high cycle fatigue (HCF). Especially for a bladed disk with a free-standing blade structure, it is essential to use a sufficiently large safety factor at the design stage, considering the mistuning effect. Traditionally, blade designers have adopted various countermeasures to reduce the resonant stress at the design stage. Besides the countermeasures adopted in blade design, for a variable speed engine, which cannot avoid resonance, it is thought that a practical optimization method for a mistuned system (bladed disk with a free-standing blade structure) is to sort the blades so that the resonant stress is minimized. In this study, a simultaneous method for optimizing the blade resonant stress and the amount of unbalance causing rotor vibration is proposed. In this method, first, the natural frequencies and weights of all blades on a disk are measured. Then, a mistuned system is assembled and the analysis model is generated. Next, the resonant stress and the amount of unbalance in the mistuned system are analyzed. To reduce the computation time, the reduced-order model known as fundamental mistuning model (FMM) is used to calculate the resonant stress in the mistuned system. The analyses of the resonant stress and the amount of unbalance are carried out repeatedly, sorting the blades on the disk, and the optimal solution is explored using Monte Carlo simulations (MCS) or discrete differential evolution (DDE). As an example, a mistuned bladed disk of an aero-engine was analyzed and the validity of the proposed method was verified.
Effects of Cylindrical-Hole Shape and Fillet on Flow and Temperature Fields in Vane Cascade With Endwall Film-Cooling
Authors: Huyssen B. B. , Mahmood G. I.
Published: January 2021

The aerodynamic performances of the cascade can be improved using the filleted blade profile. The non-uniform distributions of the endwall film-cooling flow from the cylindrical coolant holes have prompted the investigations of cascade flow-field employing several variations of the cylindrical coolant hole geometry. While some variants of the cylindrical hole show potential of improved film-cooling effectiveness on the endwall, the aerodynamic performances of the cascade on the other hand suffer. This paper presents results from the measurements of the flow-field and air temperature along a cascade passage that employs filleted vanes and endwall film-cooling using a diffused shape of the cylindrical coolant holes. The experimental results are also presented in the same vane cascade with the endwall film-cooling using the regular cylindrical coolant holes and without the fillet at the vane endwall junction. The diffused coolant hole is a smooth geometric variation of diffused area of the cylindrical hole and diffuses the coolant flow smoothly along the hole axis. The objectives are to investigate the effects of the fillet and new diffused cylindrical hole on the cascade aerodynamic performances. The effects are illuminated through the interactions of the coolant streams with the mainstream. The measurements are obtained in a linear atmospheric cascade employing a two-dimensional vane profile and an inlet Reynolds number of 2.0E+06. The axis of the coolant holes are oriented at 30° to the endwall at inlet from the coolant plenum. The coolant holes are employed both at upstream and inside of the cascade passage. The fillet extends from the leading edge region to half-way of the vane profile. The time-averaged local velocities, total pressures, and air temperatures are measured at different pitchwise planes in the cascade for the different cases at the endwall. The density ratio of the coolant flow to mainstream is about 1.0 for the flow-field measurements and about 0.94 for the temperature measurements. The overall blowing ratio of the film-cooling flow varies between 1.0 and 2.8. The results of the yaw angle deviations of endwall region flow, total pressure loss coefficients, and non-dimensional temperatures are then presented to provide the effects of the fillet and film-cooling hole geometry. The results show the desirable performances of the local distributions and concentrations of the coolant streams, the low flow turning near endwall, and the reduction of total pressure losses are better when the diffused holes are employed without the presence of fillet. With the fillet and diffused cylindrical holes, the aforementioned aerodynamic performances are improved further compared to those for the regular cylindrical coolant holes.
Vibration Fatigue Assessment of Additive Manufactured Nickel Alloy With Inherent Damping
Authors: Scott-Emuakpor Onome , Sheridan Luke , Runyon Brian , George Tommy
Published: January 2021

The fatigue life behavior and internal surface conditions of inherently damped Additive Manufactured (AM) specimens subjected to vibration bending are under investigation. This study supports research that demonstrated 95% vibration suppression due to damping capability of AM components with 1–3% internal volume of unfused powder. The damping demonstrations have been carried out using laser powder bed fusion (LPBF) specimens of various thicknesses, lengths, and unfused internal powder configurations. In addition, damping is shown to be achievable with both nickel-based alloys and stainless steel specimens. Despite the promise of this method, the viability of fatigue performance is unknown. The following effort aims to address this structural integrity issue; specifically, this study explores whether internal pocket roughness or erosion caused by powder particle motion induces a fatigue life debit. These concerns are addressed by comparing the fatigue behaviors of unfused powder pocket and fully-fused nickel based alloy 718 specimens. Microscopy results confirmed a long suspected powder interaction phenomena as well as appearances of erosion. Furthermore, fractography supports that fatigue failures initiate near the surface of maximum strain/stress at porous features consistent with stock (non-optimized) LPBF process parameters.
Large-Eddy Simulation of the Variable Speed Power Turbine Cascade With Inflow Turbulence
Authors: Miki Kenji , Ameri Ali
Published: January 2021

Numerical results are presented from the NASA Glenn Research Center’s in-house turbomachinery code, Glenn-HT applied to the Variable Speed Power Turbine (VSPT) experiment at the NASA Transonic Turbine Blade Cascade Facility. The main goal of this paper is to implement a digital filtering method to generate turbulence upstream and a sub-grid model (Localized dynamic k-equation model (LDKM)) in the framework of LES in order to investigate the effect of inflow turbulence on the transition seen in the VSPT experimental data at the cruise condition (incidence angle of 40° and Tu = 0.5%, 5%, 10%, and 15%). Although the boundary layer on the suction side and pressure side of the blades is initially laminar due to favorable pressure gradient, the laminar flow can transition to turbulent flow past a separation zone on the suction side or by natural or by-pass transition. This process determines the total-pressure losses in the wake. Therefore, it is desirable to develop a reliable prediction tool to accurately capture the transition mechanism in blade rows operated under the conditions of low Reynolds number and at a variety of free stream turbulence conditions. Our numerical studies reveal that the location of separation is rather insensitive to the level of Tu, however the effect of increasing Tu seems to be in reducing the size and ultimately suppressing the separation bubble. In addition, we performed spectral analysis to identify the peak frequencies in the region where the separation bubble is formed, which provides valuable insights into the transition/separation mechanism.
Gradient-Based Optimization of a Radial Turbine Volute and a Downstream Bend Using Vertex Morphing
Authors: Lachenmaier Nicolas , Baumgärtner Daniel , Schiffer Heinz-Peter , Kech Johannes
Published: January 2021

The higher the efficiency of a turbocharger’s radial turbine, the lower is the necessary pressure ratio to deliver a specified power to the compressor. This, in turn, reduces the fuel consumption of the internal combustion engine as a lower pressure upstream of the turbine increases the obtained charge-cycle work. In this paper, two components of a nozzled radial turbine system are redesigned: Both the volute upstream and the 90°-bend downstream of the turbine wheel will be improved. To reduce pressure drops, a gradient-based shape optimization workflow based on adjoint methods is applied. The scheme works in an iterative manner, i.e. after running a primal and an adjoint simulation to gather shape sensitivities, the geometry is deformed and the next iteration is started. A steepest descent approach is used to guide the optimization process. As parametrization strategy the Vertex Morphing Method is used to explore design potential, while maintaining smooth surfaces. Both the volute and the bend are optimized successfully leading to an efficiency increase of the turbine system of up to 3%, depending on the load condition.
Gas Labyrinth Seals: Improved Prediction of Leakage in Gas Labyrinth Seals Using an Updated Kinetic Energy Carry-Over Coefficient
Authors: Wu Tingcheng , San Andrés Luis
Published: January 2021

Though simple and fast, bulk-flow models (BFMs) for gas labyrinth seals (LSs) often predict the mass flow inaccurately. The BFM models rely on classical Neumann’s equation model to characterize the flow through a labyrinth tooth. Presently, a CFD analysis quantifies the effects of tip clearance (Cr) and operating conditions on the prediction of LS mass flow, and then derives an updated kinetic energy carry-over coefficient (μ1i) to improve the accuracy of Neumann’s leakage equation. μ1i is a function of the seal tip clearance (Cr), the tooth pitch, and the total teeth number; but it does not depend on the seal supply or discharge pressures. The analysis selects a fourteen teeth on stator LS (Length/Diameter = L/D = 0.29) with clearance Cr = (1/733)D and operating at nominal supply (Pin) and discharge (Pout) pressures equal to 73 bar and 51 bar, respectively, and at a rotor speed of 12 krpm (surface speed = 138 m/s.). The CFD produces flow fields for LSs with a clearance varying from 80% to 200% of the nominal Cr, a gas supply pressure from 60 bar to 100 bar, and with various discharge pressures giving a pressure ratio (PR = Pout/Pin) ranging from 0.40 to 0.85. The numerous predictions deliver the mass flow as well as the bulk-flow velocities and cavity pressures within the seals. The kinetic energy carry-over coefficient (μ1i) increases with respect to the seal radial clearance (Cr). μ1i shows a parabolic correlation with PR; at first μ1i increases with a rise in PR from a low value; and then a further increase in PR leads to a decrease in μ1i. The coefficient μ1i is only sensitive to the pressure ratio and not to the magnitude of either the supply or discharge pressures. Lastly, for use with Neumann’s leakage model, the CFD predictions produce an updated μ1i, a function of the seal geometry and the PR condition. Integration of the new μ1i correlation into a BFM code improves its accuracy to predict LS mass flow rate, a 19% difference against test data reduces to within 6%. A TOS LS tested by Ertas et al. (2012) serves to further validate the accuracy of the modified leakage model.
Flow Distortion Into the Core Engine for an Installed Variable Pitch Fan in Reverse Thrust Mode
Authors: Rajendran David John , Pachidis Vassilios
Published: January 2021

The flow distortion at core engine entry for a Variable Pitch Fan (VPF) in reverse thrust mode is described from a realistic flow field obtained using an integrated airframe-engine model. The model includes the VPF, core entry splitter, complete bypass nozzle flow path wrapped in a nacelle and installed to an airframe in landing configuration through a pylon. A moving ground plane to mimic the rolling runway is included. 3D RANS solutions are generated at two combinations of VPF stagger angle and rotational speed settings for the entire aircraft landing run from 140 to 20 knots. The internal reverse thrust flow field is characterized by bypass nozzle lip separation, pylon wake and recirculation of flow turned back from the VPF. A portion of the reverse stream flow turns 180° with separation at the splitter leading edge to feed the core engine. The core engine feed flow exhibits circumferential and radial non-uniformities that depend on the reverse flow development at different landing speeds. The temporal dependence of the distorted flow features is also explored by an URANS analysis.

Total pressure and swirl angle distortion descriptors, as defined by the Society of Automotive Engineers (SAE) S-16 committee, and, total pressure loss into the core engine are described for the core feed flow at different operating conditions and landing speeds. It is observed that the radial intensity of total pressure distortion is critical to core engine operation, while the circumferential intensity is within acceptable limits. Therefore, the baseline sharp splitter edge is replaced by two larger rounded splitter edges of radii, ∼0.1x and ∼0.2x times the core duct height. This was found to reduce the radial intensity of total pressure distortion to acceptable levels. The description of the installed core feed flow distortion, as described in this study, is necessary to ascertain stable core engine operation, which powers the VPF in reverse thrust mode.
Factors of Influence on the Leakage of Brush Seals
Authors: Fuchs Alexander , Göttler Johann , Haidn Oskar J.
Published: January 2021

Based on previous research from the authors a modeling approach for brush seals is developed further. Each individual bristle is reproduced in both the fluid dynamics and the structural mechanics model. An investigation regarding the influence of the free bristle height and the sealing gap on the leakage mass flow rate is carried out. Results are compared to experimental and literature data. Furthermore, preliminary results of the segregated fluid-structure interaction model are presented briefly, and matched to literature data.