bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural basis of ion transport and inhibition in ferroportin
Authors: Pan Yaping , Ren Zhenning , Gao Shuai , Shen Jiemin , Wang Lie , Xu Zhichun , Yu Ye , Bachina Preetham , Zhang Hanzhi , Fan Xiao , Laganowsky Arthur , Yan Nieng , Zhou Ming 
Published: November 2020

AbstractFerroportin is an iron exporter essential for releasing cellular iron into circulation. Ferroportin is inhibited by a peptide hormone, hepcidin. In humans, mutations in ferroportin lead to ferroportin diseases that are often associated with accumulation of iron in macrophages and symptoms of iron deficiency anemia. Here we present the structures of the ferroportin from the primate Philippine tarsier (TsFpn) in the presence and absence of hepcidin solved by cryo-electron microscopy. TsFpn is composed of two domains resembling a clamshell and the structure defines two metal ion binding sites, one in each domain. Both structures are in an outward-facing conformation, and hepcidin binds between the two domains and reaches one of the ion binding sites. Functional studies show that TsFpn is an electroneutral H+/Fe2+ antiporter so that transport of each Fe2+ is coupled to transport of two H+ in the opposite direction. Perturbing either of the ion binding sites compromises the coupled transport of H+ and Fe2+. These results establish the structural basis of metal ion binding, transport and inhibition in ferroportin and provide a blueprint for targeting ferroportin in pharmacological intervention of ferroportin diseases.
A new Majorana platform in an Fe-As bilayer superconductor
Authors: Liu Wenyao , Cao Lu , Zhu Shiyu , Kong Lingyuan , Wang Guangwei , Papaj Michał , Zhang Peng , Liu Ya-Bin , Chen Hui , Li Geng , Yang Fazhi , Kondo Takeshi , Du Shixuan , Cao Guang-Han , Shin Shik , Fu Liang , Yin Zhiping , Gao Hong-Jun , Ding Hong 
Published: November 2020

AbstractIron-chalcogenide superconductors have emerged as a promising Majorana platform for topological quantum computation. By combining topological band and superconductivity in a single material, they provide significant advantage to realize isolated Majorana zero modes. However, iron-chalcogenide superconductors, especially Fe(Te,Se), suffer from strong inhomogeneity which may hamper their practical application. In addition, some iron-pnictide superconductors have been demonstrated to have topological surface states, yet no Majorana zero mode has been observed inside their vortices, raising a question of universality about this new Majorana platform. In this work, through angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy measurement, we identify Dirac surface states and Majorana zero modes, respectively, for the first time in an iron-pnictide superconductor, CaKFe4As4. More strikingly, the multiple vortex bound states with integer-quantization sequences can be accurately reproduced by our model calculation, firmly establishing Majorana nature of the zero mode.
N-type organic thermoelectrics: demonstration of ZT > 0.3
Authors: Liu Jian , van der Zee Bas , Alessandri Riccardo , Sami Selim , Dong Jingjin , Nugraha Mohamad I. , Barker Alex J. , Rousseva Sylvia , Qiu Li , Qiu Xinkai , Klasen Nathalie , Chiechi Ryan C. , Baran Derya , Caironi Mario , Anthopoulos Thomas D. , Portale Giuseppe , Havenith Remco W. A. , Marrink Siewert J. , Hummelen Jan C. , Koster L. Jan Anton 
Published: November 2020

AbstractThe ‘phonon-glass electron-crystal’ concept has triggered most of the progress that has been achieved in inorganic thermoelectrics in the past two decades. Organic thermoelectric materials, unlike their inorganic counterparts, exhibit molecular diversity, flexible mechanical properties and easy fabrication, and are mostly ‘phonon glasses’. However, the thermoelectric performances of these organic materials are largely limited by low molecular order and they are therefore far from being ‘electron crystals’. Here, we report a molecularly n-doped fullerene derivative with meticulous design of the side chain that approaches an organic ‘PGEC’ thermoelectric material. This thermoelectric material exhibits an excellent electrical conductivity of >10 S cm−1 and an ultralow thermal conductivity of <0.1 Wm−1K−1, leading to the best figure of merit ZT = 0.34 (at 120 °C) among all reported single-host n-type organic thermoelectric materials. The key factor to achieving the record performance is to use ‘arm-shaped’ double-triethylene-glycol-type side chains, which not only offer excellent doping efficiency (~60%) but also induce a disorder-to-order transition upon thermal annealing. This study illustrates the vast potential of organic semiconductors as thermoelectric materials.
Active learning for the power factor prediction in diamond-like thermoelectric materials
Authors: Sheng Ye , Wu Yasong , Yang Jiong , Lu Wencong , Villars Pierre , Zhang Wenqing 
Published: November 2020

AbstractThe Materials Genome Initiative requires the crossing of material calculations, machine learning, and experiments to accelerate the material development process. In recent years, data-based methods have been applied to the thermoelectric field, mostly on the transport properties. In this work, we combined data-driven machine learning and first-principles automated calculations into an active learning loop, in order to predict the p-type power factors (PFs) of diamond-like pnictides and chalcogenides. Our active learning loop contains two procedures (1) based on a high-throughput theoretical database, machine learning methods are employed to select potential candidates and (2) computational verification is applied to these candidates about their transport properties. The verification data will be added into the database to improve the extrapolation abilities of the machine learning models. Different strategies of selecting candidates have been tested, finally the Gradient Boosting Regression model of Query by Committee strategy has the highest extrapolation accuracy (the Pearson R = 0.95 on untrained systems). Based on the prediction from the machine learning models, binary pnictides, vacancy, and small atom-containing chalcogenides are predicted to have large PFs. The bonding analysis reveals that the alterations of anionic bonding networks due to small atoms are beneficial to the PFs in these compounds.
The role of hyaluronic acid and hyaluronidase-1 in obstructive sleep apnoea
Authors: Meszaros Martina , Kis Adrian , Kunos Laszlo , Tarnoki Adam Domonkos , Tarnoki David Laszlo , Lazar Zsofia , Bikov Andras 
Published: November 2020

AbstractBiological functions of hyaluronic acid (HA) depend on its molecular size. High-molecular weight HA (HMW-HA) is an important component of the endothelial wall and has anti-inflammatory and antioxidant properties. Under inflammation or hypoxia, HMW-HA is degraded by hyaluronidases, such as HYAL-1 resulting in pro-inflammatory low-molecular weight fragments. Obstructive sleep apnoea (OSA) is characterised by intermittent hypoxia and systemic inflammation. Our aim was to evaluate circulating HMW-HA and HYAL-1 in OSA. We recruited 68 patients with OSA and 40 control volunteers. After full-night sleep study blood samples were taken for HMW-HA and HYAL-1 measurements. HYAL-1 levels were significantly higher in patients with OSA compared to controls (0.59/0.31–0.88/ng/mL vs. 0.31/0.31–0.58/ng/mL; p = 0.005) after adjustment for gender, age, BMI and smoking. There was a trend for reduced HMW-HA concentrations in OSA (31.63/18.11–59.25/ng/mL vs. 46.83/25.41–89.95/ng/mL; p = 0.068). Significant correlation was detected between circulating HMW-HA and apnoea-hypopnoea-index (r = − 0.195, p = 0.043), HYAL-1 and apnoea-hypopnoea-index (r = 0.30, p < 0.01) as well as oxygen desaturation index (r = 0.26, p < 0.01). Our results suggest that chronic hypoxia is associated with increased plasma HYAL-1 concentration and accelerated HMW-HA degradation. Altered hyaluronan metabolism may be involved in the inflammatory cascade potentially leading to endothelial dysfunction in OSA.
In-situ porosity recognition for laser additive manufacturing of 7075-Al alloy using plasma emission spectroscopy
Authors: Ren Wenjing , Mazumder Jyoti 
Published: November 2020

AbstractPoor quality and low repeatability of additively manufactured parts are key technological obstacles for the widespread adoption of additive manufacturing (AM). In-situ monitoring and control of the AM process is vital to overcome this problem. This paper describes the combined artificial intelligence and plasma emission spectroscopy to identify the porosity of AM parts during the process. The time- and position-synchronized spectra were collected during the directed energy deposition (DED) manufacturing process of a 7075-Al alloy part. Eighteen features extracted from spectra were coupled with the deposition qualities which were characterized by the 3D X-ray Computed Tomography (CT) scan and used to train a Random Forest (RF) classifier. The well-trained RF classifier achieved up to 83% precision for the porosity recognition of depositions. The feature importance recorded by the RF classifier indicates that the intensities of spectra at the wavelength of 414.234 (Fe I) nm and 396.054 (Al I) nm, and the kurtosis of spectra at wavelength ranges of 484–490 nm and 508–518 nm, are the most effective features for porosity recognition. The physical correlations between spectra, porosity formation, and thermal accumulation during the AM process were analyzed. This study demonstrates the great potentials, as well as challenges of plasma emission spectroscopy for in-situ quality monitoring of laser AM which allows the enhancement of AM technique.
Resolving the systematics of Richtersiidae by multilocus phylogeny and an integrative redescription of the nominal species for the genus Crenubiotus (Tardigrada)
Authors: Stec Daniel , Vecchi Matteo , Maciejowski Wojciech , Michalczyk Łukasz 
Published: November 2020

AbstractThe family Richtersiidae, although established recently with the use of phylogenetic methods, was considered potentially paraphyletic at the time of its erection. Until now, the family comprised four genera, Richtersius, Diaforobiotus, Adorybiotus and a newly erected genus Crenubiotus. However, the genetic characterisation for the latter two genera was very limited or absent. To address concerns about the phylogenetic affinity of these two genera, we present a multilocus phylogeny of the families Richtersiidae and Murrayidae based on four molecular markers (18S rRNA, 28S rRNA, ITS-2 and COI). Our results show a distinct evolutionary lineage composed of Adorybiotus and Crenubiotus, which is sister to Murrayidae. In order to accommodate the phylogenetic and morphological distinctiveness of this lineage, we erect a new family, Adorybiotidae fam. nov. The new taxon differs morphologically from other families in the superfamily Macrobiotoidea by a unique combination of traits: (1) the presence of tubercles/cushions with aggregations of microgranules on their surfaces present on all legs and on the dorso-caudal cuticle, (2) a system of internal septa in claws, and (3) buccal apparatus morphology. Moreover, in order to stabilise the taxonomy and nomenclature in the genus Crenubiotus, we redescribe its type species, Crenubiotus crenulatus, by means of integrative taxonomy and designate a new neotype based on a population from the original terra typica.
Field induced crossover in critical behaviour and direct measurement of the magnetocaloric properties of La0.4Pr0.3Ca0.1Sr0.2MnO3
Authors: Ghorai Sagar , Skini Ridha , Hedlund Daniel , Ström Petter , Svedlindh Peter 
Published: November 2020

AbstractLa0.4Pr0.3Ca0.1Sr0.2MnO3 has been investigated as a potential candidate for room temperature magnetic refrigeration. Results from X-ray powder diffraction reveal an orthorhombic structure with Pnma space group. The electronic and chemical properties have been confirmed by X-ray photoelectron spectroscopy and ion-beam analysis. A second-order paramagnetic to ferromagnetic transition was observed near room temperature (289 K), with a mean-field like critical behaviour at low field and a tricritical mean-field like behaviour at high field. The field induced crossover in critical behaviour is a consequence of the system being close to a first-order magnetic transition in combination with a magnetic field induced suppression of local lattice distortions. The lattice distortions consist of interconnected and weakly distorted pairs of Mn-ions, where each pair shares an electron and a hole, dispersed by large Jahn–Teller distortions at Mn3+ lattice sites. A comparatively high value of the isothermal entropy-change (3.08 J/kg-K at 2 T) is observed and the direct measurements of the adiabatic temperature change reveal a temperature change of 1.5 K for a magnetic field change of 1.9 T.
18F-THK5351 PET imaging in patients with progressive supranuclear palsy: associations with core domains and diagnostic certainty
Authors: Hsu Jung-Lung , Chen Shih-Hsin , Hsiao Ing-Tsung , Lu Chin-Song , Yen Tzu-Chen , Okamura Nobuyuki , Lin Kun-Ju , Weng Yi-Hsin 
Published: November 2020

AbstractThe associations of 18F-THK5351 tau positron emission tomography (PET) findings with core domains of progressive supranuclear palsy (PSP) and its diagnostic certainty have yet to be fully elucidated. The 18F-THK5351 PET patterns of 17 patients with PSP (68.9 ± 6.5 years; 8 women) were compared with those observed in 28 age-matched and sex-matched (66.2 ± 4.5 years, 18 women) control subjects (CS). Tracer accumulation—as reflected by standardized uptake value ratios (SUVRs) and z-scores—was correlated with core domains of PSP and different levels of diagnostic certainty. Compared with CS, patients with PSP showed an increased 18F-THK5351 uptake in the globus pallidus and red nucleus. Patients with PSP and oculomotor dysfunction had significantly higher SUVRs in the midbrain, red nucleus, and raphe nucleus than those without. In addition, cases who meet criteria for level 1 (highest) certainty in the postural instability domain showed significantly higher SUVRs in the frontal, parietal, precuneus, and sensory-motor cortex. Patients with probable PSP had significantly higher SUVR values than those with possible PSP in multiple cortical (i.e., frontal, parietal, temporal, anterior cingulate gyrus, precuneus, and sensory-motor gyrus) and subcortical (i.e., putamen, thalamus, and raphe nucleus) regions. Patterns of 18F-THK5351 uptake were correlated to core domains of PSP—including oculomotor dysfunction and postural instability. Moreover, the degree of diagnostic certainty for PSP was appreciably associated with 18F-THK5351 PET findings.
Delphi methodology for symptomatology associated with visual dysfunctions
Authors: Cantó-Cerdán Mario , Cacho-Martínez Pilar , García-Muñoz Ángel 
Published: November 2020

AbstractTo analyse what eyecare clinicians think about which symptoms are associated with refractive, accommodative and binocular dysfunctions, and which of them should be used in a questionnaire of visual symptomatology. A Delphi method was developed, using a coordinating group and a group of experts, and the process was conducted in three rounds. In the first round we compiled a list of 34 symptoms from the scientific literature and additional 10 suggested by the experts. These symptoms were categorized by each expert to the associated visual anomalies and working distance. In the second round, the relationship between each symptom and visual dysfunctions was analysed using a numeric scale. In the third round, the appearance or absence of the 44 symptoms in a questionnaire was assessed. Symptoms most frequently assigned by the experts to visual anomalies were related to near vision. Symptoms of blurred vision, difficulty focusing from one distance to another and close one eye obtained the highest mean score for refractive, accommodative and binocular disorders respectively. The experts were in agreement for 15 symptoms and in disagreement for 5 symptoms that should appear in a questionnaire. Delphi method has been used to identify the symptoms related to visual dysfunctions according to eyecare professionals and has allowed to arrive at appropriate symptoms to be asked for in a visual symptomatology questionnaire.
Antibiotic-induced DNA damage results in a controlled loss of pH homeostasis and genome instability
Authors: Booth James Alexander , Špírek Mário , Lobie Tekle Airgecho , Skarstad Kirsten , Krejci Lumir , Bjørås Magnar 
Published: November 2020

AbstractExtracellular pH has been assumed to play little if any role in how bacteria respond to antibiotics and antibiotic resistance development. Here, we show that the intracellular pH of Escherichia coli equilibrates to the environmental pH following treatment with the DNA damaging antibiotic nalidixic acid. We demonstrate that this allows the environmental pH to influence the transcription of various DNA damage response genes and physiological processes such as filamentation. Using purified RecA and a known pH-sensitive mutant variant RecA K250R we show how pH can affect the biochemical activity of a protein central to control of the bacterial DNA damage response system. Finally, two different mutagenesis assays indicate that environmental pH affects antibiotic resistance development. Specifically, at environmental pH’s greater than six we find that mutagenesis plays a significant role in producing antibiotic resistant mutants. At pH’s less than or equal to 6 the genome appears more stable but extensive filamentation is observed, a phenomenon that has previously been linked to increased survival in the presence of macrophages.
Genome-wide scan for selection signatures reveals novel insights into the adaptive capacity in local North African cattle
Authors: Ben-Jemaa Slim , Mastrangelo Salvatore , Lee Seung-Hwan , Lee Jun Heon , Boussaha Mekki 
Published: November 2020

AbstractNatural-driven selection is supposed to have left detectable signatures on the genome of North African cattle which are often characterized by the fixation of genetic variants associated with traits under selection pressure and/or an outstanding genetic differentiation with other populations at particular loci. Here, we investigate the population genetic structure and we provide a first outline of potential selection signatures in North African cattle using single nucleotide polymorphism genotyping data. After comparing our data to African, European and indicine cattle populations, we identified 36 genomic regions using three extended haplotype homozygosity statistics and 92 outlier markers based on Bayescan test. The 13 outlier windows detected by at least two approaches, harboured genes (e.g. GH1, ACE, ASIC3, HSPH1, MVD, BCL2, HIGD2A, CBFA2T3) that may be involved in physiological adaptations required to cope with environmental stressors that are typical of the North African area such as infectious diseases, extended drought periods, scarce food supply, oxygen scarcity in the mountainous areas and high-intensity solar radiation. Our data also point to candidate genes involved in transcriptional regulation suggesting that regulatory elements had also a prominent role in North African cattle response to environmental constraints. Our study yields novel insights into the unique adaptive capacity in these endangered populations emphasizing the need for the use of whole genome sequence data to gain a better understanding of the underlying molecular mechanisms.
Developmental differences in the intestinal microbiota of Chinese 1-year-old infants and 4-year-old children
Authors: Guo Min , Miao Maohua , Wang Yuezhu , Duan Mengmeng , Yang Fen , Chen Yao , Yuan Wei , Zheng Huajun 
Published: November 2020

AbstractThe microbiota profile of children changes with age. To investigate the differences in the gut microbiota profile of 1- and 4-year-old children, we collected fecal samples and sequenced the V3–V4 hypervariable region of the 16S rRNA gene via high-throughput DNA sequencing. From phylum to species level, the microbiota underwent significant changes with age. The abundance of phyla Proteobacteria and Actinobacteria declined with age, whereas phyla Firmicutes and Bacteroidetes increased with age and dominated the gut microbiota of 4-year-olds. The intestinal environment of children at age four is closer to maturity. Hence, the abundance of Bifidobacterium significantly decreased in the gut of 4-year-olds, whereas Akkermansia muciniphila increased from 0.14% in 1-year-olds to 4.25% in 4-year-olds. The functional change in gut microbiota is consistent with changes in infant food, as microbiota participating in amino acid and vitamin metabolism were enriched in 1-year-olds, whereas microbiota involved in lipid metabolism increased with age.
Antioxidant activity and mechanism of inhibitory action of gentisic and α-resorcylic acids
Authors: Mardani-Ghahfarokhi Azadeh , Farhoosh Reza 
Published: November 2020

AbstractThe antioxidant activity of gentisic (GA) and α-resorcylic (α-RA) acids was investigated by considering their molecular structures in various oxidative environments, including DPPH· scavenging assay, stripped olive and soybean oils, and the corresponding oil-in-water emulsions. The mechanism of action in the oils was evaluated in the presence of different concentrations of the antioxidants at 60 °C, using the kinetic parameters the stabilization factor (F), the oxidation rate ratio (ORR), the activity (A), and the average rate of antioxidant consumption ($$\overline{r}_{{{\text{AH}}}}$$

r
¯

AH

). GA was significantly more potent antioxidant than α-RA in all the environments. Although the less polar α-RA showed better activity in the emulsions rather than in the bulk oils, GA with an ortho-hydroxy structure had higher capacity to scavenge DPPH·, and LOO· in the oils and emulsions. The lower performance of α-RA was attributed to its participation in side reactions of chain initiation (AH + LOOH → A· + L· + H2O) and propagation (A· + LH → AH + L·) as competed with the main chain termination reaction (LOO· + AH → LOOH + A·).
Recovery of motor function of chronic spinal cord injury by extracellular pyruvate kinase isoform M2 and the underlying mechanism
Authors: Kikuchi Takahiro , Tohda Chihiro , Suyama Masato 
Published: November 2020

AbstractIn our previous study, we found that pyruvate kinase isoform M2 (PKM2) was secreted from the skeletal muscle and extended axons in the cultured neuron. Indirect evidence suggested that secreted PKM2 might relate to the recovery of motor function in spinal cord injured (SCI) mice. However, in vivo direct evidence has not been obtained, showing that extracellular PKM2 improved axonal density and motor function in SCI mice. In addition, the signal pathway of extracellular PKM2 underlying the increase in axons remained unknown. Therefore, this study aimed to identify a target molecule of extracellular PKM2 in neurons and investigate the critical involvement of extracellular PKM2 in functional recovery in the chronic phase of SCI. Recombinant PKM2 infusion to the lateral ventricle recovered motor function in the chronic phase of SCI mice. The improvement of motor function was associated with axonal increase, at least of raphespinal tracts connecting to the motor neurons directly or indirectly. Target molecules of extracellular PKM2 in neurons were identified as valosin-containing protein (VCP) by the drug affinity responsive target stability method. ATPase activation of VCP mediated the PKM2-induced axonal increase and recovery of motor function in chronic SCI related to the increase in axonal density. It is a novel finding that axonal increase and motor recovery are mediated by extracellular PKM2-VCP-driven ATPase activity.