bluuebunny/crossref_metadata_2025_split huggingface dataset:
Virtual screening as a tool to discover new β-haematin inhibitors with activity against malaria parasites
Authors: de Sousa Ana Carolina C. , Combrinck Jill M. , Maepa Keletso , Egan Timothy J. 
Published: February 2020

AbstractMalaria remains a major public health problem. With the loss of antimalarials to resistance, the malaria burden will likely continue for decades. New antimalarial scaffolds are crucial to avoid cross-resistance. Here, we present the first structure based virtual screening using the β-haematin crystal as a target for new inhibitor scaffolds by applying a docking method. The ZINC15 database was searched for compounds with high binding affinity with the surface of the β-haematin crystal using the PyRx Virtual Screening Tool. Top-ranked compounds predicted to interact with β-haematin were submitted to a second screen applyingin silicotoxicity and drug-likeness predictions using Osiris DataWarrior. Fifteen compounds were purchased for experimental testing. An NP-40 mediated β-haematin inhibition assay and parasite growth inhibition activity assay were performed. The benzoxazole moiety was found to be a promising scaffold for further development, showing intraparasitic haemozoin inhibition using a cellular haem fractionation assay causing a decrease in haemozoin in a dose dependent manner with a corresponding increase in exchangeable haem. A β-haematin inhibition hit rate of 73% was found, a large enrichment over random screening, demonstrating that virtual screening can be a useful and cost-effective approach in the search for new haemozoin inhibiting antimalarials.
A Comparison Study of Precipitation in the Poyang and the Dongting Lake Basins from 1960–2015
Authors: Guo Ruifang , Zhu Yaqiao , Liu Yuanbo 
Published: February 2020

AbstractThe Dongting Lake Basin and the Poyang Lake Basin, both located in the middle reaches of the Yangtze River, provide 30% of the total water volume for the Yangtze River. Under global climate change, precipitation patterns have undergone varying degrees of changes in different regions. Analysing temporal and spatial rainfall variations is important for understanding the variations in capacity of the two lake basins and the water intake variations by the Yangtze River. This study analyses the temporal and spatial variations of the two basins based on 33 rain-gauge data series from 1960–2015, using statistical methods, GIS spatial analysis and the M-K trend test. Our results showed that the annual precipitation generally increased in the Poyang Lake Basin and we found no obvious changes in the Dongting Lake Basin from 1960 to 2015. Seasonal precipitation levels at interannual scales were roughly consistent, but exhibited variability larger by an order of magnitude in the Poyang Lake Basin than in the Dongting Lake Basin. In general, an increasing trend dominated in spring and autumn while a decreasing trend was observed in summer and winter. The increasing trend was significant from the 1990s in the Poyang Lake Basin and from the late 1990s in the Dongting Lake Basin. It was found that annual precipitation with relatively larger anomalies appeared in ENSO (El Niño and Southern Oscillation) years in most cases, such as in 1963, 1997/1998 and 2002, while a few anomalies appeared in the previous or next year around an ENSO year, such as 1971 and 1978. All monthly precipitation periods with relatively larger or smaller anomalies coincided with ENSO events. In addition, El Niño and SOI (Southern Oscillation) events had significant relationships with negative monthly precipitation anomalies. El Niño and the SOI exerted more significant impacts on the Poyang Lake Basin than on the Dongting Lake Basin, which explains the conclusions regarding seasonal precipitation trends as mentioned above.
Association between ossification of the longitudinal ligament of the cervical spine and arteriosclerosis in the carotid artery
Authors: Oshima Yasushi , Doi Toru , Kato So , Taniguchi Yuki , Matsubayashi Yoshitaka , Nakajima Koji , Oguchi Fumihiko , Oka Hiroyuki , Hayashi Naoto , Tanaka Sakae 
Published: February 2020

AbstractAlthough several risk factors have been reported for cervical ossification of the longitudinal ligament (OPLL), most evaluations made in the past were based on plain X-ray, not on computed tomography (CT) scan. In this study, we aimed to clarify novel risk factors for cervical OPLL in asymptomatic subjects undergoing CT scan as their routine medical checkups. A total of 1789 Japanese asymptomatic subjects who underwent CT scan for the whole body as their routine medical checkups were retrospectively reviewed. The medical checkup also included laboratory examinations, bone mineral status, and ultrasound of the carotid artery. As a result, cervical OPLL was seen in 120 subjects (6.7%). As we compared the demographic and clinical data between subjects with and without OPLL, OPLL group showed older age, higher proportion of male sex, higher BMI, higher incidence of hypertension, higher levels of blood HbA1c and triglyceride, and higher incidence of plaques in the carotid artery. A multivariate logistic regression analysis revealed that age (Odds ratio (OR):1.03), male sex (OR: 1.91), and the presence of plaque in the carotid artery (OR: 1.71) were risk factors for OPLL. To the best of our knowledge, this is the first report to reveal an association between OPLL and arteriosclerotic lesions.
Chimpanzee Coordination and Potential Communication in a Two-touchscreen Turn-taking Game
Authors: Voinov Pavel V. , Call Josep , Knoblich Günther , Oshkina Marina , Allritz Matthias 
Published: February 2020

AbstractRecent years have seen a growing interest in the question of whether and how groups of nonhuman primates coordinate their behaviors for mutual benefit. On the one hand, it has been shown that chimpanzees in the wild and in captivity can solve various coordination problems. On the other hand, evidence of communication in the context of coordination problems is scarce. Here, we investigated how pairs of chimpanzees (Pan troglodytes) solved a problem of dynamically coordinating their actions for achieving a joint goal. We presented five pairs of chimpanzees with a turn-taking coordination game, where the task was to send a virtual target from one computer display to another using two touch-screens. During the joint practice of the game some subjects exhibited spontaneous gesturing. To address the question whether these gestures were produced to sustain coordination, we introduced a joint test condition in which we simulated a coordination break-down scenario: subjects appeared either unwilling or unable to return the target to their partner. The frequency of gesturing was significantly higher in these test trials than in the regular trials. Our results suggest that at least in some contexts chimpanzees can exhibit communicative behaviors to sustain coordination in joint action.
Dissolved organic matter-mediated photodegradation of anthracene and pyrene in water
Authors: Zhao Siyu , Xue Shuang , Zhang Jinming , Zhang Zhaohong , Sun Jijun 
Published: February 2020

AbstractToxicity and transformation process of polycyclic aromatic hydrocarbons (PAHs) is strongly depended on the interaction between PAHs and dissolved organic matters (DOM). In this study, a 125W high-pressure mercury lamp was used to simulate the sunlight experiment to explore the inhibition mechanism of four dissolved organic matters (SRFA, LHA, ESHA, UMRN) on the degradation of anthracene and pyrene in water environment. Results indicated that the photodegradation was the main degradation approach of PAHs, which accorded with the first-order reaction kinetics equation. The extent of degradation of anthracene and pyrene was 36% and 24%, respectively. DOM influence mechanism on PAHs varies depending upon its source. SRFA, LHA and ESHA inhibit the photolysis of anthracene, however, except for SRFA, the other three DOM inhibit the photolysis of pyrene. Fluorescence quenching mechanism is the main inhibiting mechanism, and the binding ability of DOM and PAHs is dominantly correlated with its inhibiting effect. FTIR spectroscopies and UV–Visible were used to analyze the main structural changes of DOM binding PAHs. Generally, the stretching vibration of N–H and C–O of polysaccharide carboxylic acid was the key to affect its binding with anthracene and C–O–C in aliphatic ring participated in the complexation of DOM and pyrene.
Distinct surfaces on Cdc5/PLK Polo-box domain orchestrate combinatorial substrate recognition during cell division
Authors: Almawi Ahmad W. , Langlois-Lemay Laurence , Boulton Stephen , Rodríguez González Javier , Melacini Giuseppe , D’Amours Damien , Guarné Alba 
Published: February 2020

AbstractPolo-like kinases (Plks) are key cell cycle regulators. They contain a kinase domain followed by a polo-box domain that recognizes phosphorylated substrates and enhances their phosphorylation. The regulatory subunit of the Dbf4-dependent kinase complex interacts with the polo-box domain of Cdc5 (the sole Plk in Saccharomyces cerevisiae) in a phosphorylation-independent manner. We have solved the crystal structures of the polo-box domain of Cdc5 on its own and in the presence of peptides derived from Dbf4 and a canonical phosphorylated substrate. The structure bound to the Dbf4-peptide reveals an additional density on the surface opposite to the phospho-peptide binding site that allowed us to propose a model for the interaction. We found that the two peptides can bind simultaneously and non-competitively to the polo-box domain in solution. Furthermore, point mutations on the surface opposite to the phosphopeptide binding site of the polo-box domain disrupt the interaction with the Dbf4 peptide in solution and cause an early anaphase arrest phenotype distinct from the mitotic exit defect typically observed in cdc5 mutants. Collectively, our data illustrates the importance of non-canonical interactions mediated by the polo-box domain and provide key mechanistic insights into the combinatorial recognition of substrates by Polo-like kinases.
Risk of cadmium, lead and zinc exposure from consumption of vegetables produced in areas with mining and smelting past
Authors: Ćwieląg-Drabek Małgorzata , Piekut Agata , Gut Klaudia , Grabowski Mateusz 
Published: February 2020

AbstractThe study reveals links between disturbed geochemical environment being the result of mining and smelting activities with consumers exposure to toxic and carcinogenic metallic trace elements (MTEs). This study focused on evaluation on vegetable and soil pollution in family allotment gardens (FAGs), considering in the aspects of consumer exposure to cadmium, lead and zinc. Study material consisted of 219 soil samples from FAGs located in one of the most polluted areas in Poland, and 64 samples of edible plants. Contents of analyzed MTEs in topsoil in the studied area were spatially diversified and depended primarily on the location of industrial pollution sources. The average content of cadmium (0.52 mg kg−1fresh weight) and lead (0.57 mg kg−1fresh weight) in vegetables exceeded maximum permissible concentrations according to the European Quality Standards. Human health risk assessment was based on three scenarios of dietary exposure to cadmium, lead and zinc. In every scenario the highest average daily dose for all three elements was estimated for potatoes which are one of the main components of Poles’ diet. Presented study showed that consumption of vegetables cultivated in FAGs located in Silesia Province may pose a significant health risk for their consumers.
Rational Design of Photo-Electrochemical Hybrid Devices Based on Graphene and Chlamydomonas reinhardtii Light-Harvesting Proteins
Authors: Ortiz-Torres Martha I. , Fernández-Niño Miguel , Cruz Juan C. , Capasso Andrea , Matteocci Fabio , Patiño Edgar J. , Hernández Yenny , González Barrios Andrés Fernando 
Published: February 2020

AbstractDye-sensitized solar cells (DSSCs) have been highlighted as the promising alternative to generate clean energy based on low pay-back time materials. These devices have been designed to mimic solar energy conversion processes from photosynthetic organisms (the most efficient energy transduction phenomenon observed in nature) with the aid of low-cost materials. Recently, light-harvesting complexes (LHC) have been proposed as potential dyes in DSSCs based on their higher light-absorption efficiencies as compared to synthetic dyes. In this work, photo-electrochemical hybrid devices were rationally designed by adding for the first time Leu and Lys tags to heterologously expressed light-harvesting proteins from Chlamydomonas reinhardtii, thus allowing their proper orientation and immobilization on graphene electrodes. The light-harvesting complex 4 from C. reinhardtii (LHC4) was initially expressed in Escherichia coli, purified via affinity chromatography and subsequently immobilized on plasma-treated thin-film graphene electrodes. A photocurrent density of 40.30 ± 9.26 μA/cm2 was measured on devices using liquid electrolytes supplemented with a phosphonated viologen to facilitate charge transfer. Our results suggest that a new family of graphene-based thin-film photovoltaic devices can be manufactured from rationally tagged LHC proteins and opens the possibility to further explore fundamental processes of energy transfer for biological components interfaced with synthetic materials.
Natural selection supports escape from concerted evolution of a recently duplicated CEACAM1 paralog in the ruminant CEA gene family
Authors: Hänske Jana , Hammacher Tim , Grenkowitz Franziska , Mansfeld Martin , Dau Tung Huy , Maksimov Pavlo , Friedrich Christin , Zimmermann Wolfgang , Kammerer Robert 
Published: February 2020

AbstractConcerted evolution is often observed in multigene families such as the CEA gene family. As a result, sequence similarity of paralogous genes is significantly higher than expected from their evolutionary distance. Gene conversion, a “copy paste” DNA repair mechanism that transfers sequences from one gene to another and homologous recombination are drivers of concerted evolution. Nevertheless, some gene family members escape concerted evolution and acquire sufficient sequence differences that orthologous genes can be assigned in descendant species. Reasons why some gene family members can escape while others are captured by concerted evolution are poorly understood. By analyzing the entire CEA gene family in cattle (Bos taurus) we identified a member (CEACAM32) that was created by gene duplication and cooption of a unique transmembrane domain exon in the most recent ancestor of ruminants. CEACAM32 shows a unique, testis-specific expression pattern. Phylogenetic analysis indicated that CEACAM32 is not involved in concerted evolution of CEACAM1 paralogs in ruminants. However, analysis of gene conversion events revealed that CEACAM32 is subject to gene conversion but remarkably, these events are found in the leader exon and intron sequences but not in exons coding for the Ig-like domains. These findings suggest that natural selection hinders gene conversion affecting protein sequences of the mature protein and thereby support escape of CEACAM32 from concerted evolution.
Leucine-rich alpha 2 glycoprotein is a new marker for active disease of tuberculosis
Authors: Fujimoto Minoru , Matsumoto Tomoshige , Serada Satoshi , Tsujimura Yusuke , Hashimoto Shoji , Yasutomi Yasuhiro , Naka Tetsuji 
Published: February 2020

AbstractTuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is a global health problem. At present, prior exposure to Mtb can be determined by blood-based interferon-gamma release assay (IGRA), but active TB is not always detectable by blood tests such as CRP and ESR. This study was undertaken to investigate whether leucine-rich alpha-2 glycoprotein (LRG), a new inflammatory biomarker, could be used to assess active disease of TB. Cynomolgus macaques pretreated with or without Bacille Calmette-Guerin (BCG) vaccination were inoculated with Mtb to induce active TB. Blood was collected over time from these animals and levels of LRG as well as CRP and ESR were quantified. In the macaques without BCG vaccination, Mtb inoculation caused extensive TB and significantly increased plasma CRP and LRG levels, but not ESR. In the macaques with BCG vaccination, whereas Mtb challenge caused pulmonary TB, only LRG levels were significantly elevated. By immunohistochemical analysis of the lung, LRG was visualized in epithelioid cells and giant cells of the granulation tissue. In humans, serum LRG levels in TB patients were significantly higher than those in healthy controls and declined one month after anti-tubercular therapy. These findings suggest that LRG is a promising biomarker when performed following IGRA for the detection of active TB.
300 GHz optical waveform measurement by novel THz‐wave autocorrelator
Authors: Yamamoto R. , Ichiyama K. , Che M. , Kuboki T. , Ito H. , Ishibashi T. , Kato K. 
Published: February 2020

A novel THz‐wave autocorrelator consisting of an optical delay line and high‐speed photodiodes was proposed for the measurement of optical waveforms with a high rate of repetition. In this system, the waveform is delayed at the optical domain and correlated at the THz domain. Experimental results show clear autocorrelations of 100, 200 and 300 GHz sinusoidal waveforms which indicate the feasibility of the proposed method.
Discovery of technetium- and niobium-rich S stars: The case for bitrinsic stars
Authors: Shetye S. , Van Eck S. , Goriely S. , Siess L. , Jorissen A. , Escorza A. , Van Winckel H. 
Published: February 2020

Context. S stars are late-type giants with overabundances of s-process elements. They come in two flavors depending on the presence or lack of presence of technetium (Tc), an element without stable isotopes. Intrinsic S stars are Tc-rich and genuine asymptotic giant branch (AGB) stars, while extrinsic S stars owe their s-process over abundances to the pollution from a former AGB companion, which is now a white dwarf (WD). In addition to Tc, another distinctive feature between intrinsic and extrinsic S stars is the overabundance of niobium (Nb) in the latter class. Indeed, since the mass transfer occurred long ago, 93Zr had time to decay into the only stable isotope of Nb, 93Nb, causing its overabundance.
Aims. We discuss the case of the S stars BD+79°156 and o1 Ori, whose specificity lies in sharing the distinctive features of both intrinsic and extrinsic S stars, namely the presence of Tc along with a Nb overabundance.
Methods. We used high-resolution HERMES optical spectra, MARCS model atmospheres of S stars, Gaia DR2 parallaxes, and STAREVOL evolutionary tracks to determine the stellar parameters and chemical abundances of the two S stars, and to locate them in the Hertzsprung-Russell (HR) diagram.
Results. BD+79°156 is the first clear case of a bitrinsic star, that is, a doubly s-process-enriched object, first through mass transfer in a binary system and then through internal nucleosynthesis that is responsible for the Tc-enrichment in BD+79°156, which must, therefore, have reached the AGB phase of its evolution. This hybrid nature of the s-process pattern in BD+79°156 is supported by its binary nature and its location in the HR diagram that is just beyond the onset of the third dredge-up on the AGB. The Tc-rich, binary S-star o1 Ori with a WD companion was another long-standing candidate for a similar hybrid s-process enrichment. However, the marginal overabundance of Nb derived in o1 Ori does not allow one to trace evidence of large amounts of pollution coming from the AGB progenitor of its current WD companion unambiguously. As a side product, the current study offers a new way of detecting binary AGB stars with WD companions by identifying their Tc-rich nature along with a Nb overabundance.
New white dwarf envelope models and diffusion
Authors: Koester D. , Kepler S. O. , Irwin A. W. 
Published: February 2020

Context.Recent studies of the atmospheres of carbon-rich (DQ) white dwarfs have demonstrated the existence of two different populations that are distinguished by the temperature range, but more importantly, by the extremely high masses of the hotter group. The classical DQ below 10 000 K are well understood as the result of dredge-up of carbon by the expanding helium convection zone. The high-mass group poses several problems regarding their origin and also an unexpected correlation of effective temperature with mass.Aims.We propose to study the envelopes of these objects to determine the total hydrogen and helium masses as possible clues to their evolution.Methods.We developed new codes for envelope integration and diffusive equilibrium that are adapted to the unusual chemical composition, which is not necessarily dominated by hydrogen and helium.Results.Using the new results for the atmospheric parameters, in particular, the masses obtained usingGaiaparallaxes, we confirm that the narrow sequence of carbon abundances withTeffin the cool classical DQ is indeed caused by an almost constant helium to total mass fraction, as found in earlier studies. This mass fraction is smaller than predicted by stellar evolution calculations. For the warm DQ above 10 000 K, which are thought to originate from double white dwarf mergers, we obtain extremely low hydrogen and helium masses. The correlation of mass withTeffremains unexplained, but another possible correlation of helium layer masses withTeffas well as the gravitational redshifts casts doubt on the reality of both and suggests possible shortcomings of current models.
Dynamics of life expectancy and life span equality
Authors: Aburto José Manuel , Villavicencio Francisco , Basellini Ugofilippo , Kjærgaard Søren , Vaupel James W. 
Published: February 2020

Significance
Why life expectancy and life span equality have increased together is a question of scientific interest. Both measures are calculated for a calendar year and might not describe a cohort’s actual life course. Nonetheless, life expectancy provides a useful measure of average life spans, and life span equality gives insights into uncertainty about age at death. We show how patterns of change in life expectancy and life span equality are described by trajectories of mortality improvements over age and time. The strength of the relationship between life expectancy and life span equality is not coincidental but rather a result of progress in saving lives at specific ages: the more lives saved at the youngest ages, the stronger the relationship is.
Evaluation of a concerted vs. sequential oxygen activation mechanism in α-ketoglutarate–dependent nonheme ferrous enzymes
Authors: Goudarzi Serra , Iyer Shyam R. , Babicz Jeffrey T. , Yan James J. , Peters Günther H. J. , Christensen Hans E. M. , Hedman Britt , Hodgson Keith O. , Solomon Edward I. 
Published: February 2020

Significance
Many iron-dependent enzymes utilize molecular oxygen to functionalize inert C–H bonds in biology. Nonheme ferrous enzymes perform these reactions by reducing dioxygen, often in the presence of a sacrificial electron donor, to form a reactive intermediate that converts substrate to product. In α-ketoglutarate (αKG)–dependent enzymes, there has been discussion on the necessity of substrate prebinding to the αKG-bound ferrous center for productive chemistry. This study demonstrates that, when substrate is not prebound to the enzyme, the species generated in the reaction with dioxygen is not competent to perform hydrogen atom abstraction from the substrate. In contrast, when both cosubstrates are prebound to the enzyme, efficient coupling between dioxygen reduction and substrate oxidation is observed, leading to productive chemistry.