bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bone morphogenetic protein 15 supplementation enhances cumulus expansion, nuclear maturation and progesterone production of in vitro‐matured bovine cumulus‐oocyte complexes
Authors: Delgado Juliana de Carvalho , Hamilton Thais Rose dos Santos , Mendes Camilla Mota , Siqueira Adriano Felipe Perez , Goissis Marcelo Demarchi , Buratini José , Assumpção Mayra Elena Ortiz D’Ávila 
Published: February 2021

AbstractIn vitro embryo production (IVP) efficiency is reduced when compared to in vivo. The basic knowledge of bovine in vitro oocyte maturation (IVM) mechanisms provides support to improve in vitro embryo production yields. The present study assessed the effects of bone morphogenetic protein 15 (BMP15), fibroblast growth factor 16 (FGF16) and their combined action on cumulus cells (CC) expansion, oocyte and CC DNA fragmentation, oocyte nuclear maturation, energetic metabolism and progesterone production in bovine IVM. Cumulus‐oocyte complexes (COC) were matured in control or supplemented media containing BMP15 (100 ng/ml), FGF16 (10 ng/ml) or BMP15 combined with FGF16; and assessed at 0 and 22 hr of IVM. BMP15 alone or its association with FGF16 enhanced cumulus expansion. BMP15 decreased DNA fragmentation in both CC and oocytes, and improved oocyte nuclear maturation rate. In addition, BMP15 increased CC progesterone production, an effect not previously reported. The present study reinforces previous data pointing to a beneficial influence of BMP15 during IVM, while providing novel evidence that the underlying mechanisms involve increased progesterone production.
Conceptual Change and Future Paths for Pragmatism
Authors: Shields Matthew 
Published: February 2021

AbstractThe pragmatist faces the challenge of accounting for the possibility of rational conceptual change. Some pragmatists have tried to meet this challenge by appealing to Neurathian imagery—imagery that risks being too figurative to be helpful. I argue that we can develop a clearer view of what rationally constrained conceptual revision looks like for the pragmatist. I do so by examining the work of the pragmatist who in recent years has addressed this issue most directly, Richard Rorty. His attempts to solve the puzzle ultimately fall short, but prove instructive. Rorty characterizes inter‐language transitions in exclusively causal terms because, along with the very philosophical traditions he criticizes, he uncritically privileges the role of truth claims or assertions in our pragmatics. I show that if we instead broaden our pragmatic imaginations, we encounter various non‐assertoric speech acts involved in speakers aiming to change how we make sense of our language and concepts. With these acts in view, we are able to arrive at a demystified view of rational conceptual change from a pragmatist perspective and identify future lines of inquiry for pragmatist projects.
Exercise training decreases whole‐body and tissue iron storage in adults with obesity
Authors: Ryan Benjamin J. , Foug Katherine L. , Gioscia‐Ryan Rachel A. , Varshney Pallavi , Ludzki Alison C. , Ahn Cheehoon , Schleh Michael W. , Gillen Jenna B. , Chenevert Thomas L. , Horowitz Jeffrey F. 
Published: February 2021

New Findings
What is the central question of this study?
Does exercise training modify tissue iron storage in adults with obesity?

What is the main finding and its importance?
Twelve weeks of moderate‐intensity exercise or high‐intensity interval training lowered whole‐body iron stores, decreased the abundance of the key iron storage protein in skeletal muscle (ferritin) and tended to lower hepatic iron content. These findings show that exercise training can reduce tissue iron storage in adults with obesity and might have important implications for obese individuals with dysregulated iron homeostasis.
AbstractThe regulation of iron storage is crucial to human health, because both excess and deficient iron storage have adverse consequences. Recent studies suggest altered iron storage in adults with obesity, with increased iron accumulation in their liver and skeletal muscle. Exercise training increases iron use for processes such as red blood cell production and can lower whole‐body iron stores in humans. However, the effects of exercise training on liver and muscle iron stores in adults with obesity have not been assessed. The aim of this study was to determine the effects of 12 weeks of exercise training on whole‐body iron stores, liver iron content and the abundance of ferritin (the key iron storage protein) in skeletal muscle in adults with obesity. Twenty‐two inactive adults (11 women and 11 men; age, 31 ± 6 years; body mass index, 33 ± 3 kg/m2) completed 12 weeks (four sessions/week) of either moderate‐intensity continuous training (MICT; 45 min at 70% of maximal heart rate; n = 11) or high‐intensity interval training (HIIT; 10 × 1 min at 90% of maximal heart rate, interspersed with 1 min active recovery; n = 11). Whole‐body iron stores were lower after training, as indicated by decreased plasma concentrations of ferritin (P = 3 × 10−5) and hepcidin (P = 0.02), without any change in C‐reactive protein. Hepatic R2*, an index of liver iron content, was 6% lower after training (P = 0.06). Training reduced the skeletal muscle abundance of ferritin by 10% (P = 0.03), suggesting lower muscle iron storage. Interestingly, these adaptations were similar in MICT and HIIT groups. Our findings indicate that exercise training decreased iron storage in adults with obesity, which might have important implications for obese individuals with dysregulated iron homeostasis.
Turbine Hub Cavity Modes and Their Impact on Efficiency
Authors: Iranidokht Vahid , Purwar Naman , Kalfas Anestis I , Abhari Reza S , Senoo Shigeki 
Published: February 2021

Abstract
Non-synchronous pressure and temperature fluctuations at the hub cavity of a turbine stage are the main focus of this study. Cavity modes are unsteady fluctuations generated at the cavity exit due to instabilities in this region. The cavity modes carried into the main flow impose an unsteady flow field in the rotor passages, which varies the passage-wise flow parameters considerably. A two-stage axial turbine was designed and tested in the “LISA” test facility at ETH Zurich. A reference case with baseline geometry and a modified case with an axial deflector at the hub cavity exit were tested. Comprehensive unsteady pressure and temperature measurements were performed using fast response aerodynamic (FRAP) and entropy probes (FENT), respectively. In addition, 12 fast response unsteady pressure transducers were mounted on the stationary wall of the cavity exit to measure the main characteristic parameters of the cavity modes. Full annular unsteady simulations were also carried out for both cases to support the experiments. Computational fluid dynamics (CFD) successfully predicted the effect of cavity modes on both frequency and amplitude of the fluctuations. The cavity modes indicated fluctuation amplitudes up to eight times of the blade passing fluctuations at the cavity exit. The analysis shows that the convected cavity modes alter the efficiency of different rotor passages by redistributing the mass flow and the losses resulting in a drop in overall efficiency. This work suggests that implementing a small axial deflector at the hub cavity exit would completely eliminate the cavity modes leading to a reduced pressure unsteadiness and enhanced efficiency.
Heat Transfer Characteristics Within the Matrix Cooling Channels
Authors: Tariq Andallib , Prajapati Anjana N. 
Published: February 2021

Abstract
Matrix or latticework cooling has become a new area of research due to its advantage of providing a structural rigidity to the fragile structures like gas turbine blades, electronic components or circuitries, and compact heat exchangers. In this article, the heat transfer characteristics in matrix cooling channels with different rib angles have been studied using liquid crystal thermography. A total of three matrix models with rib angles 35 deg, 45 deg, and 55 deg having a common subchannel aspect ratio 0.8 have been studied. The results are evaluated in terms of local and average augmentation Nusselt numbers for different regions of the matrix. The augmentation Nusselt number has been found to increase in each region as the angle increases from 35 deg to 45 deg and the same has been found to decrease slightly upon the further increase in angle from 45 deg to 55 deg. The highest percentage increase in augmentation Nusselt number up to 50% has been observed in entry region, whereas the same remained nearly 26–30% in middle and exit regions in streamwise directions, i.e., the effect of the matrix rib angle is more prominent in the entry region. The higher resistance offered by the greater number of ribs for angle 55 deg is believed to be responsible for the decrease in augmentation Nusselt number for Re ≤ 9000.
Effect of Radiation on Heat Transfer Inside Aeroengine Compressor Rotors
Authors: Tang Hui , Owen J. Michael 
Published: February 2021

AbstractThe blade clearance in aero-engine compressors is mainly controlled by the radial growth of the compressor discs, to which the blades are attached. This growth depends on the radial distribution of the disc temperature, which in turn is determined by the heat transfer inside the internal rotating cavity between adjacent discs. The buoyancy-induced convection inside the cavity is significantly weaker than that associated with the forced convection in the external mainstream flow, and consequently radiation between the cavity surfaces cannot be ignored in the calculation of the disc temperatures. In this paper, both the Monte Carlo Ray-Trace (MCRT) method and the view factor (VF) method are used to calculate the radiative flux when the temperatures of the discs, shroud, and inner shaft of the compressor vary radially and axially. The Monte Carlo Ray-Trace method is computationally expensive, but it is able to incorporate the effect of complex geometries on radiation. The view factor method is quick to compute and, although the derivation becomes complicated when geometrical details are considered, it can be used as a first check of the effect of radiation in compressor cavities. Given distributions of surface temperatures, the blackbody and gray body heat fluxes were calculated for the discs, shroud, and inner shaft in two experimental compressor rigs and in a simulated compressor stage. For the experimental rigs, although the effect of radiation was relatively small for the case of large Grashof numbers, the relative effect of radiation increases as Gr (and consequently the convective heat transfer) decreases. For the simulated compressor, with a pressure ratio of 50:1 for state-of-the-art aircraft engines, radiation could have a significant effect on the disc temperature and consequently on the blade clearance; the effect is predicted to be more prominent for the next generation of aircraft engines with pressure ratios up to 70:1.
Experimental Study of Vaneless Diffuser Rotating Stall Development and Cell-Merging Phenomena
Authors: Grapow Filip , Olasek Krzysztof , Liśkiewicz Grzegorz , Magiera Radomir , Kryłłowicz Władysław 
Published: February 2021

Abstract
This paper describes the vaneless diffuser rotating stall (VDRS) development and cell-merging phenomena. A centrifugal compressor’s lifespan may be limited by flow instabilities occurring in off-design operation. One such instability is the VDRS, which generates oscillating, asymmetrical flow fields in the diffuser and, thus, undesired forces acting on the rotor. Understanding and prevention of VDRS behavior are crucial for achieving safe and undisturbed compressor operation. Experimental measurements of centrifugal compressors operating under the influence of VDRS have been presented. Two different approaches were used for the identification of VDRS: pressure measurements and two-dimensional (2D) particle image velocimetry (PIV). Frequency analysis based on spectral maps and cell development processes were investigated. The presented results showed that mass flowrate has an impact on the rotating frequency of both the entire structure and single cells. Additionally, it affects radial cell size, which grows with compressor throttling and ultimately reaches the length of the diffuser. During the experiments, the cell-merging phenomenon was observed which has not been widely described in the literature. The results presented in this paper allow a better understanding of vaneless diffuser rotating stall behavior. The phenomenon of the change of cell size and frequency could be very important for machine fatigue. Cell-merging could also have an impact on the machine’s vibrations and flow stability. Since it is believed that VDRS is one of the factors inducing surge, its understanding and prevention may have a positive influence on surge margins.
Experimental Test and Estimation of the Equivalent Thermoelectric Properties for a Thermoelectric Module
Authors: Luo Ding , Wang Ruochen 
Published: February 2021

Abstract
When analyzing and optimizing the performance of thermoelectric (TE) devices in theory, Seebeck coefficient, thermal conductivity, and electrical resistivity are indispensable TE properties. However, most manufacturers do not provide or overestimate these data. Under the consideration of temperature dependence, this paper discloses an experimental measurement approach to estimate the equivalent Seebeck coefficient, thermal conductivity, and electrical resistivity of a TE module. A thermal resistance network is also established to work out the hot and cold side temperatures of TE legs. Based on a designed test bench, required temperature and electrical parameters in both open circuit and closed circuit are measured and recorded, where the data of open circuit are used to calculate the equivalent Seebeck coefficient and thermal conductivity, and the data of closed circuit are used to calculate the equivalent electrical resistivity. To eliminate the error of parasitic internal resistance, a thermal-electric finite element model is adopted to modify the equivalent electrical resistivity. The modification results indicate that the equivalent internal resistance is about 1.033 times the real internal resistance, and the ratio is related to the working temperature. This work provides a new idea to obtain the TE material properties via an experimental test.
The Effect of Bionic 3D Printed Structure Morphology on Skin Friction
Authors: Zhihao Zhang , Makoto Ito , Xishu Wang , Jinsheng Liu 
Published: February 2021

Abstract
Dragonfly has remarkable flight efficiency, with unique wing structural properties such as the surface topological vein structures, corrugation, etc. The object of this paper is to identify how the polygonal patterns of the samples with bionic wing veins affected the skin friction. Four kinds of polygonal three-dimensional (3D) patterns were designed and fabricated by additive manufacturing technology, and the skin friction coefficients (Cf) of various models were measured by the wind channel experiments. The quantitative effects of models on Cf with different Reynolds numbers (Re) in laminar, transitional, and turbulent flow conditions were obtained. Results indicated that the law of whole change of the skin friction coefficient versus Re is the same for all patterns which can be expressed by an empirical formula Cf=kReα. The model with mixed square and pentagonal patterns always generates the highest skin friction in the different flow conditions, which was speculated to play an important role on the attenuation of the flow separation of the dragonfly wing.
Formation of High-Temperature Minerals From an Evaporite-Rich Dust in Gas Turbine Engine Ingestion Tests
Authors: Elms Jacob , Pawley Alison , Bojdo Nicholas , Jones Merren , Clarkson Rory 
Published: February 2021

Abstract
The ingestion of multi-mineral dusts by gas turbine engines during routine operations is a significant problem for engine manufacturers because of the damage caused to engine components and their protective thermal barrier coatings. A complete understanding of the reactions forming these deposits is limited by a lack of knowledge of compositions of ingested dusts and unknown engine conditions. Testbed engines can be dosed with dusts of known composition under controlled operating conditions, but past engine tests have used standardized test dusts that do not resemble the composition of the background dust in the operating regions. New evaporite-rich test dust was developed and used in a full engine ingestion test, designed to simulate operation in regions with evaporite-rich geology, such as Doha or Dubai. Analysis of the engine deposits showed that mineral fractionation was present in the cooler, upstream sections of the engine. In the hotter, downstream sections, deposits contained new, high-temperature phases formed by the reaction of minerals in the test dust. The mineral assemblages in these deposits are similar to those found from previous analyses of service returns. Segregation of anhydrite from other high-temperature phases in a deposited sample taken from a high-pressure turbine blade suggests a relationship between temperature and sulfur content. This study highlights the potential for manipulating deposit chemistry to mitigate the damage caused in the downstream sections of gas turbine engines. The results of this study also suggest that the concentration of ingested dust in the inlet air may not be a significant contributing factor to deposit chemistry.
Structure Synthesis of a Class of Parallel Manipulators With Fully Decoupled Projective Motion
Authors: Kuo Chin-Hsing , Dai Jian S. 
Published: February 2021

Abstract
This paper describes the structure synthesis of a special class of parallel manipulators with fully decoupled motion, that is, a one-to-one correspondence between the instantaneous motion space of the end-effector and the joint space of the manipulator. A notable finding of this study is that a fully decoupled design can be achieved for parallel manipulators with any number of degrees-of-freedom (DOFs) when the rotational DOF of the end-effector is expressed in the form of a projective angle representation. On the basis of the geometrical reasoning of the projective motion interpreted by screw algebra, a systematic approach is developed for synthesizing the structures of f-DOF (f ≤ 6) parallel manipulators with fully decoupled projective motion. Several 2-, 3-, 4-, 5-, and 6-DOF parallel manipulators with fully decoupled projective motion were designed for illustrating the developed method.
Modelling the determinants of health and cancers as perceived by children: using imagery as a mediator of expression and narration
Authors: Gay Chloé , Deyra Maeliane , Berland Pauline , Gerbaud Laurent , Pizon Frank 
Published: February 2021

ObjectivesTo model and analyse conceptions of determinants of health and cancer that are expressed and perceived by school children aged 6–11 based on a multiphase qualitative protocol.MethodologyThis is a multicentric, qualitative study of human and social sciences conducted among school children aged 6–11 years old. Two different tools were used, e.Photoexpression and Photonarration, in four French schools. This innovative and exploratory method addresses global health during the first phase (e.Photoexpression) and the theme of cancer during the second phase (Photonarration). The children express themselves through photography and narration.Results1498 qualitative productions were made by 381 children aged 6–11 years old. The analysis of these productions of expression and narration through images allowed modelling of determinants of health and cancer as perceived by children through 7 fields and 28 categories. The conceptions of determinants of health and child cancer refer to rationalities that are centred on individual determinants (76%), minimise environmental determinants (20%) and conceal the parameters of access to healthcare and social services (3%).DiscussionThese findings provide new data to the international literature on children’s perceptions of determinants of health and cancer. These research findings, which can be applied to interventions and current practices, will enable prevention workers to act more effectively, closer to children’s perceptions and needs.
SARS-CoV-2 genome and antibodies in breastmilk: a systematic review and meta-analysis
Authors: Zhu Faith , Zozaya Carlos , Zhou Qi , De Castro Charmaine , Shah Prakesh S 
Published: February 2021

ObjectiveTo systematically review and meta-analyse the rate of SARS-CoV-2 genome identification and the presence of SARS-CoV-2 antibodies in breastmilk of mothers with COVID-19.DesignA systematic review of studies published between January 2019 and October 2020 without study design or language restrictions.SettingData sourced from Ovid Embase Classic+Embase, PubMed, Web of Science, Scopus, relevant bibliographies and the John Hopkins University COVID-19 database.PatientsMothers with confirmed COVID-19 and breastmilk tested for SARS-CoV-2 by RT-PCR or for anti-SARS-CoV-2 antibodies.Main outcome measuresPresence of SARS-CoV-2 genome and antibodies in breastmilk.ResultsWe included 50 articles. Twelve out of 183 women from 48 studies were positive for SARS-CoV-2 genome in their breastmilk (pooled proportion 5% (95% CI 2% to 15%; I2=48%)). Six infants (50%) of these 12 mothers tested positive for SARS-CoV-2, with one requiring respiratory support. Sixty-one out of 89 women from 10 studies had anti-SARS-CoV-2 antibody in their breastmilk (pooled proportion 83% (95% CI 32% to 98%; I2=88%)). The predominant antibody detected was IgA.ConclusionsSARS-CoV-2 genome presence in breastmilk is uncommon and is associated with mild symptoms in infants. Anti-SARS-CoV-2 antibodies may be a more common finding. Considering the low proportion of SARS-CoV-2 genome detected in breastmilk and its lower virulence, mothers with COVID-19 should be supported to breastfeed.