bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of Choline‐Based Deep Eutectic Solvents in the Extraction of Tocols from Crude Palm Oil
Authors: Abdul Hadi Nu’man , Ng Mei Han , Choo Yuen May , Hashim Mohd Ali , Jayakumar Natesan Subramanian 
Published: September 2015

AbstractDeep eutectic solvents are emerging green solvents that have potential in many separation processes. This study investigates the performance of choline‐based deep eutectic solvents in the extraction of tocopherols and tocotrienols (collectively known as tocols) from palm oil, a major natural source of tocols. Deep eutectic solvents comprised of choline chloride salt and selected carboxylic acids as hydrogen bond donors were prepared and used in the extraction of tocols from crude palm oil by liquid–liquid extraction. Tocols concentration in the extracted product was at least double that in the control (8671 mg/kg compared to 3285 mg/kg, respectively). Increasing the amount of the deep eutectic solvents increased the tocols concentration in the extracted product up to 18,525 mg/kg, but the yields lowered from 4 % to less than 1 %. The tocols profile was significantly improved by the increase of the tocotrienols fraction in the products from 80.8 to 99.8 %. This study showed that unique interaction between the selected deep eutectic solvents with the tocols make it possible to selectively separate individual tocols in palm oil, where products with fractions rich in tocotrienols and low in tocopherols (particularly α‐tocopherol) are favorable.
Soaking Conditions Affect the Contents of Tocopherols, Tocotrienols, and γ‐Oryzanol in Pigmented and Non‐Pigmented Brown Rice
Authors: Lin Tsu‐Chi , Huang Shao‐Hua , Ng Lean‐Teik 
Published: September 2015

AbstractTocopherols (Toc), tocotrienols (T3), and γ‐oryzanol (GO), important lipid antioxidants in rice, are known to possess various pharmacological properties. In this study, our aim was to examine the effects of soaking conditions on the extractable contents of Toc, T3, and GO in cooked pigmented (PBR) and non‐pigmented brown rice (non‐PBR). The results showed that Toc, T3, and GO concentrations in non‐PBR peaked after soaking at 25 °C for 120 min, whereas soaking conditions showed minimal effects on these compounds in PBR. In non‐PBR, high Toc, T3, and GO levels were also noted in the treatments at higher soaking temperatures (45 and 55 °C) with a shorter soaking time (less than 60 min). The GO level in both cultivars was at least ten times greater than the total vitamin E content. Vitamin E analogues having concentrations greater than 10 mg/kg in PBR and non‐PBR were γ‐Toc and γ‐T3, and α‐Toc and γ‐T3, respectively. This study concludes that presoaking and cooking processes can improve the extractable contents of Toc, T3, and GO in cooked PBR and non‐PBR, and the extraction yield of these bioactive compounds was significantly different between cultivars.
Barriers to early prenatal care in South Africa
Authors: Haddad Diane N. , Makin Jennifer D. , Pattinson Robert C. , Forsyth Brian W. 
Published: September 2015

AbstractObjectiveTo understand the barriers delaying early prenatal care for women in South Africa.MethodsA mixed‐methods study was conducted at a center in Pretoria.ResultsFollowing interviews with 21 women at a prenatal clinic in Pretoria, a quantitative survey was completed by 204 postpartum women. During interviews, women described presenting late owing to contemplating induced abortion, fear of HIV testing, and fear of jealousy and bewitching. The survey results demonstrated that a majority of women (133 [65.2%]) reported knowledge of recommendations to present before 12 weeks; however, the average gestational age at initial presentation was 19.1 ± 7.7 weeks. Women were more likely to present earlier if the pregnancy was planned (P = 0.013) and were less likely to if they had at any point contemplated induced abortion (P = 0.021). Fears of bewitching and harmful psychological stress owing to a positive HIV test result prevailed in both the interviews and the surveys.ConclusionSignificant efforts should be devoted to improving access to contraception and prepregnancy counseling in order to improve early prenatal care attendance. Similarly, addressing cultural concerns and fears regarding pregnancy is imperative in promoting early attendance.
Peak and ceiling effects in final-product analysis of mastoidectomy performance
Authors: West N , Konge L , Cayé-Thomasen P , Sørensen M S , Andersen S A W 
Published: September 2015

AbstractBackground:Virtual reality surgical simulation of mastoidectomy is a promising training tool for novices. Final-product analysis for assessing novice mastoidectomy performance could be limited by a peak or ceiling effect. These may be countered by simulator-integrated tutoring.Methods:Twenty-two participants completed a single session of self-directed practice of the mastoidectomy procedure in a virtual reality simulator. Participants were randomised for additional simulator-integrated tutoring. Performances were assessed at 10-minute intervals using final-product analysis.Results:In all, 45.5 per cent of participants peaked before the 60-minute time limit. None of the participants achieved the maximum score, suggesting a ceiling effect. The tutored group performed better than the non-tutored group but tutoring did not eliminate the peak or ceiling effects.Conclusion:Timing and adequate instruction is important when using final-product analysis to assess novice mastoidectomy performance. Improved real-time feedback and tutoring could address the limitations of final product based assessment.
Demasculinization of male guppies increases resistance to a common and harmful ectoparasite
Authors: DARGENT FELIPE , REDDON ADAM R. , SWANEY WILLIAM T. , FUSSMANN GREGOR F. , READER SIMON M. , SCOTT MARILYN E. , FORBES MARK R. 
Published: September 2015

SUMMARYParasites are detrimental to host fitness and therefore should strongly select for host defence mechanisms. Yet, hosts vary considerably in their observed parasite loads. One notable source of inter-individual variation in parasitism is host sex. Such variation could be caused by the immunomodulatory effects of gonadal steroids. Here we assess the influence of gonadal steroids on the ability of guppies (Poecilia reticulata) to defend themselves against a common and deleterious parasite (Gyrodactylus turnbulli). Adult male guppies underwent 31 days of artificial demasculinization with the androgen receptor-antagonist flutamide, or feminization with a combination of flutamide and the synthetic oestrogen 17β-estradiol, and their parasite loads were compared over time to untreated males and females. Both demasculinized and feminized male guppies had lowerG. turnbulliloads than the untreated males and females, but this effect appeared to be mainly the result of demasculinization, with feminization having no additional measurable effect. Furthermore, demasculinized males, feminized males and untreated females all suffered lowerGyrodactylus-induced mortality than untreated males. Together, these results suggest that androgens reduce the ability of guppies to control parasite loads, and modulate resistance to and survival from infection. We discuss the relevance of these findings for understanding constraints on the evolution of resistance in guppies and other vertebrates.
Neuropsychological Testing in Interventional Cardiology Staff after Long-Term Exposure to Ionizing Radiation
Authors: Marazziti Donatella , Tomaiuolo Francesco , Dell’Osso Liliana , Demi Virginia , Campana Serena , Piccaluga Emanuela , Guagliumi Giulio , Conversano Ciro , Baroni Stefano , Andreassi Maria Grazia , Picano Eugenio 
Published: September 2015

AbstractThis study aimed at comparing neuropsychological test scores in 83 cardiologists and nurses (exposed group, EG) working in the cardiac catheterization laboratory, and 83 control participants (non exposed group, nEG), to explore possible cognitive impairments. The neuropsychological assessment was carried out by means of a battery called “Esame Neuropsicologico Breve.” EG participants showed significantly lower scores on the delayed recall, visual short-term memory, and semantic lexical access ability than the nEG ones. No dose response could be detected. EG participants showed lower memory and verbal fluency performances, as compared with nEG. These reduced skills suggest alterations of some left hemisphere structures that are more exposed to IR in interventional cardiology staff. On the basis of these findings, therefore, head protection would be a mandatory good practice to reduce effects of head exposure to ionizing radiation among invasive cardiology personnel (and among other exposed professionals). (JINS, 2015,21, 670–676)
Ex vivoDetermination of an Estradiol Analogue-Induced Changes on Platelet Morphology and Angiogenic Biomarkers
Authors: Repsold Lisa , Pretorius Etheresia , Joubert Annie M. 
Published: September 2015

AbstractAngiogenesis is a closely controlled biological process that takes place during fetal development of blood vessels and wound healing, and includes the development of new blood vessels from preexisting blood vessels. Tumor angiogenesis is a means by which tumors obtain oxygen, nutrition and promote tumor growth. Angiogenesis-regulating proteins are therefore ideal biomarkers in the study of tumor pathophysiology. In our laboratory, a newin silico-designed analogue of 2-methoxyestradiol has been synthesized with angiogenic properties, namely 2-ethyl-3-O-sulfamoyl-estra-1,3,5(10)16-tetraene (ESE-16). Theex vivoinfluence of ESE-16 on angiogenesis and morphology in platelets of healthy participants was investigated. Scanning electron microscopy revealed no morphological changes in ESE-16-treated platelets. The possible antiangiogenic effect of ESE-16-exposed platelets was determined by means of flow cytometry measurement of angiogenic protein levels, which were significantly increased after platelets were added to tumorigenic breast epithelial cells. This indicates that binding of platelets to cancer cells causes differential release of platelet constituents. Vascular endothelial growth factor levels were decreased in platelets, whereas platelet-derived growth factor and matrix metallopeptidase-9 levels were not significantly affected in platelets. In light of the above-mentioned data, further investigation of ESE-16’s influence on morphology and angiogenic markers in platelets of cancer patients is warranted.
DEC1 regulates breast cancer cell proliferation by stabilizing cyclin E protein and delays the progression of cell cycle S phase
Authors: Bi H , Li S , Qu X , Wang M , Bai X , Xu Z , Ao X , Jia Z , Jiang X , Yang Y , Wu H 
Published: September 2015

AbstractBreast cancer that is accompanied by a high level of cyclin E expression usually exhibits poor prognosis and clinical outcome. Several factors are known to regulate the level of cyclin E during the cell cycle progression. The transcription factor DEC1 (also known as STRA13 and SHARP2) plays an important role in cell proliferation and apoptosis. Nevertheless, the mechanism of its role in cell proliferation is poorly understood. In this study, using the breast cancer cell lines MCF-7 and T47D, we showed that DEC1 could inhibit the cell cycle progression of breast cancer cells independently of its transcriptional activity. The cell cycle-dependent timing of DEC1 overexpression could affect the progression of the cell cycle through regulating the level of cyclin E protein. DEC1 stabilized cyclin E at the protein level by interacting with cyclin E. Overexpression of DEC1 repressed the interaction between cyclin E and its E3 ligase Fbw7α, consequently reducing the level of polyunbiquitinated cyclin E and increased the accumulation of non-ubiquitinated cyclin E. Furthermore, DEC1 also promoted the nuclear accumulation of Cdk2 and the formation of cyclin E/Cdk2 complex, as well as upregulating the activity of the cyclin E/Cdk2 complex, which inhibited the subsequent association of cyclin A with Cdk2. This had the effect of prolonging the S phase and suppressing the growth of breast cancers in a mouse xenograft model. These events probably constitute the essential steps in DEC1-regulated cell proliferation, thus opening up the possibility of a protein-based molecular strategy for eliminating cancer cells that manifest a high-level expression of cyclin E.
An intracellular replication niche for Vibrio cholerae in the amoeba Acanthamoeba castellanii
Authors: Van der Henst Charles , Scrignari Tiziana , Maclachlan Catherine , Blokesch Melanie 
Published: September 2015

Abstract
Vibrio cholerae is a human pathogen and the causative agent of cholera. The persistence of this bacterium in aquatic environments is a key epidemiological concern, as cholera is transmitted through contaminated water. Predatory protists, such as amoebae, are major regulators of bacterial populations in such environments. Therefore, we investigated the interaction between V. cholerae and the amoeba Acanthamoeba castellanii at the single-cell level. We observed that V. cholerae can resist intracellular killing. The non-digested bacteria were either released or, alternatively, established a replication niche within the contractile vacuole of A. castellanii. V. cholerae was maintained within this compartment even upon encystment. The pathogen ultimately returned to its aquatic habitat through lysis of A. castellanii, a process that was dependent on the production of extracellular polysaccharide by the pathogen. This study reinforces the concept that V. cholerae is a facultative intracellular bacterium and describes a new host–pathogen interaction.
Electronic cooling via interlayer Coulomb coupling in multilayer epitaxial graphene
Authors: Mihnev Momchil T. , Tolsma John R. , Divin Charles J. , Sun Dong , Asgari Reza , Polini Marco , Berger Claire , de Heer Walt A. , MacDonald Allan H. , Norris Theodore B. 
Published: September 2015

AbstractIn van der Waals bonded or rotationally disordered multilayer stacks of two-dimensional (2D) materials, the electronic states remain tightly confined within individual 2D layers. As a result, electron–phonon interactions occur primarily within layers and interlayer electrical conductivities are low. In addition, strong covalent in-plane intralayer bonding combined with weak van der Waals interlayer bonding results in weak phonon-mediated thermal coupling between the layers. We demonstrate here, however, that Coulomb interactions between electrons in different layers of multilayer epitaxial graphene provide an important mechanism for interlayer thermal transport, even though all electronic states are strongly confined within individual 2D layers. This effect is manifested in the relaxation dynamics of hot carriers in ultrafast time-resolved terahertz spectroscopy. We develop a theory of interlayer Coulomb coupling containing no free parameters that accounts for the experimentally observed trends in hot-carrier dynamics as temperature and the number of layers is varied.
High charge mobility in two-dimensional percolative networks of PbSe quantum dots connected by atomic bonds
Authors: Evers Wiel H. , Schins Juleon M. , Aerts Michiel , Kulkarni Aditya , Capiod Pierre , Berthe Maxime , Grandidier Bruno , Delerue Christophe , van der Zant Herre S. J. , van Overbeek Carlo , Peters Joep L. , Vanmaekelbergh Daniel , Siebbeles Laurens D. A. 
Published: September 2015

AbstractTwo-dimensional networks of quantum dots connected by atomic bonds have an electronic structure that is distinct from that of arrays of quantum dots coupled by ligand molecules. We prepared atomically coherent two-dimensional percolative networks of PbSe quantum dots connected via atomic bonds. Here, we show that photoexcitation leads to generation of free charges that eventually decay via trapping. The charge mobility probed with an AC electric field increases with frequency from 150±15 cm2 V−1 s−1 at 0.2 terahertz to 260±15 cm2 V−1 s−1 at 0.6 terahertz. Gated four-probe measurements yield a DC electron mobility of 13±2 cm2 V−1 s−1. The terahertz mobilities are much higher than for arrays of quantum dots coupled via surface ligands and are similar to the highest DC mobilities reported for PbSe nanowires. The terahertz mobility increases only slightly with temperature in the range of 15–290 K. The extent of straight segments in the two-dimensional percolative networks limits the mobility, rather than charge scattering by phonons.
Current-driven dynamics of skyrmions stabilized in MnSi nanowires revealed by topological Hall effect
Authors: Liang Dong , DeGrave John P. , Stolt Matthew J. , Tokura Yoshinori , Jin Song 
Published: September 2015

AbstractSkyrmions hold promise for next-generation magnetic storage as their nanoscale dimensions may enable high information storage density and their low threshold for current-driven motion may enable ultra-low energy consumption. Skyrmion-hosting nanowires not only serve as a natural platform for magnetic racetrack memory devices but also stabilize skyrmions. Here we use the topological Hall effect (THE) to study phase stability and current-driven dynamics of skyrmions in MnSi nanowires. THE is observed in an extended magnetic field-temperature window (15–30 K), suggesting stabilization of skyrmions in nanowires compared with the bulk. Furthermore, we show in nanowires that under the high current density of 108–109 A m−2, the THE decreases with increasing current densities, which demonstrates the current-driven motion of skyrmions generating the emergent electric field in the extended skyrmion phase region. These results open up the exploration of skyrmions in nanowires for fundamental physics and magnetic storage technologies.
Exometabolite niche partitioning among sympatric soil bacteria
Authors: Baran Richard , Brodie Eoin L. , Mayberry-Lewis Jazmine , Hummel Eric , Da Rocha Ulisses Nunes , Chakraborty Romy , Bowen Benjamin P. , Karaoz Ulas , Cadillo-Quiroz Hinsby , Garcia-Pichel Ferran , Northen Trent R. 
Published: September 2015

AbstractSoils are arguably the most microbially diverse ecosystems. Physicochemical properties have been associated with the maintenance of this diversity. Yet, the role of microbial substrate specialization is largely unexplored since substrate utilization studies have focused on simple substrates, not the complex mixtures representative of the soil environment. Here we examine the exometabolite composition of desert biological soil crusts (biocrusts) and the substrate preferences of seven biocrust isolates. The biocrust's main primary producer releases a diverse array of metabolites, and isolates of physically associated taxa use unique subsets of the complex metabolite pool. Individual isolates use only 13−26% of available metabolites, with only 2 out of 470 used by all and 40% not used by any. An extension of this approach to a mesophilic soil environment also reveals high levels of microbial substrate specialization. These results suggest that exometabolite niche partitioning may be an important factor in the maintenance of microbial diversity.
Convergent capture of retroviral superantigens by mammalian herpesviruses
Authors: Aswad Amr , Katzourakis Aris 
Published: September 2015

AbstractHorizontal gene transfer from retroviruses to mammals is well documented and extensive, but is rare between unrelated viruses with distinct genome types. Three herpesviruses encode a gene with similarity to a retroviral superantigen gene (sag) of the unrelated mouse mammary tumour virus (MMTV). We uncover ancient retroviral sags in over 20 mammals to reconstruct their shared history with herpesviral sags, revealing that the acquisition is a convergent evolutionary event. A retrovirus circulating in South American primates over 10 million years ago was the source of sag in two monkey herpesviruses, and a different retrovirus was the source of sag in a Peruvian rodent herpesvirus. We further show through a timescaled phylogenetic analysis that a cross-species transmission of monkey herpesviruses occurred after the acquisition of sag. These results reveal that a diverse range of ancient sag-containing retroviruses independently donated sag twice from two separate lineages that are distinct from MMTV.
Cyclic diguanylate monophosphate directly binds to human siderocalin and inhibits its antibacterial activity
Authors: Li Weihui , Cui Tao , Hu Lihua , Wang Ziqing , Li Zongqiang , He Zheng-Guo 
Published: September 2015

AbstractCyclic diguanylate monophosphate (c-di-GMP) is a well-conserved second messenger in bacteria. During infection, the innate immune system can also sense c-di-GMP; however, whether bacterial pathogens utilize c-di-GMP as a weapon to fight against host defense for survival and possible mechanisms underlying this process remain poorly understood. Siderocalin (LCN2) is a key antibacterial component of the innate immune system and sequesters bacterial siderophores to prevent acquisition of iron. Here we show that c-di-GMP can directly target the human LCN2 protein to inhibit its antibacterial activity. We demonstrate that c-di-GMP specifically binds to LCN2. In addition, c-di-GMP can compete with bacterial ferric siderophores to bind LCN2. Furthermore, c-di-GMP can significantly reduce LCN2-mediated inhibition on the in vitro growth of Escherichia coli. Thus, LCN2 acts as a c-di-GMP receptor. Our findings provide insight into the mechanism by which bacteria utilize c-di-GMP to interfere with the innate immune system for survival.
Oscillation of p38 activity controls efficient pro-inflammatory gene expression
Authors: Tomida Taichiro , Takekawa Mutsuhiro , Saito Haruo 
Published: September 2015

AbstractThe p38 MAP kinase signalling pathway controls inflammatory responses and is an important target of anti-inflammatory drugs. Although pro-inflammatory cytokines such as interleukin-1β (IL-1β) appear to induce only transient activation of p38 (over ∼60 min), longer cytokine exposure is necessary to induce p38-dependent effector genes. Here we study the dynamics of p38 activation in individual cells using a Förster resonance energy transfer (FRET)-based p38 activity reporter. We find that, after an initial burst of activity, p38 MAPK activity subsequently oscillates for more than 8 h under continuous IL-1β stimulation. However, as this oscillation is asynchronous, the measured p38 activity population average is only slightly higher than basal level. Mathematical modelling, which we have experimentally verified, indicates that the asynchronous oscillation of p38 is generated through a negative feedback loop involving the dual-specificity phosphatase MKP-1/DUSP1. We find that the oscillatory p38 activity is necessary for efficient expression of pro-inflammatory genes such as IL-6, IL-8 and COX-2.
Matrikines are key regulators in modulating the amplitude of lung inflammation in acute pulmonary infection
Authors: Akthar Samia , Patel Dhiren F. , Beale Rebecca C. , Peiró Teresa , Xu Xin , Gaggar Amit , Jackson Patricia L. , Blalock J. Edwin , Lloyd Clare M. , Snelgrove Robert J. 
Published: September 2015

AbstractBioactive matrix fragments (matrikines) have been identified in a myriad of disorders, but their impact on the evolution of airway inflammation has not been demonstrated. We recently described a pathway where the matrikine and neutrophil chemoattractant proline–glycine–proline (PGP) could be degraded by the enzyme leukotriene A4 hydrolase (LTA4H). LTA4H classically functions in the generation of pro-inflammatory leukotriene B4, thus LTA4H exhibits opposing pro- and anti-inflammatory activities. The physiological significance of this secondary anti-inflammatory activity remains unknown. Here we show, using readily resolving pulmonary inflammation models, that loss of this secondary activity leads to more pronounced and sustained inflammation and illness owing to PGP accumulation. PGP elicits an exacerbated neutrophilic inflammation and protease imbalance that further degrades the extracellular matrix, generating fragments that perpetuate inflammation. This highlights a critical role for the secondary anti-inflammatory activity of LTA4H and thus has consequences for the generation of global LTA4H inhibitors currently being developed.