bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rational engineering of a mesohalophilic carbonic anhydrase to an extreme halotolerant biocatalyst
Authors: Warden Andrew C. , Williams Michelle , Peat Thomas S. , Seabrook Shane A. , Newman Janet , Dojchinov Greg , Haritos Victoria S. 
Published: December 2015

AbstractEnzymes expressed by highly salt-tolerant organisms show many modifications compared with salt-affected counterparts including biased amino acid and lower α-helix content, lower solvent accessibility and negative surface charge. Here, we show that halotolerance can be generated in an enzyme solely by modifying surface residues. Rational design of carbonic anhydrase II is undertaken in three stages replacing 18 residues in total, crystal structures confirm changes are confined to surface residues. Catalytic activities and thermal unfolding temperatures of the designed enzymes increase at high salt concentrations demonstrating their shift to halotolerance, whereas the opposite response is found in the wild-type enzyme. Molecular dynamics calculations reveal a key role for sodium ions in increasing halotolerant enzyme stability largely through interactions with the highly ordered first Na+ hydration shell. For the first time, an approach to generate extreme halotolerance, a trait with broad application in industrial biocatalysis, in a wild-type enzyme is demonstrated.
MN1–Fli1 oncofusion transforms murine hematopoietic progenitor cells into acute megakaryoblastic leukemia cells
Authors: Wenge D V , Felipe-Fumero E , Angenendt L , Schliemann C , Schmidt E , Schmidt L H , Thiede C , Ehninger G , Berdel W E , Arteaga M-F , Mikesch J-H 
Published: December 2015

AbstractLong-term outcome of acute megakaryoblastic leukemia (AMKL) patients without Down’s syndrome remains poor. Founding mutations and chimeric oncogenes characterize various AMKL subtypes. However, for around one third of all cases the underlying mechanisms of AMKL leukemogenesis are still largely unknown. Recently, an in-frame fusion of meningeoma 1–friend leukemia virus integration 1 (MN1–Fli1) gene was detected in a child with AMKL. We intended to investigate the potential role of this oncofusion in leukemogenesis of acute myeloid leukemia. Strikingly, expression of MN1–Fli1 in murine hematopoietic progenitor cells was sufficient to induce leukemic transformation generating immature myeloid cells with cytomorphology and expression of surface markers typical for AMKL. Systematic structure function analyses revealed FLS and 3′ETS domains of Fli1 as decisive domains for the AMKL phenotype. Our data highlight an important role of MN1–Fli1 in AMKL leukemogenesis and provide a basis for research assessing the value of this oncofusion as a future diagnostic marker and/or therapeutic target in AMKL patients.
Constructive remodeling of a synthetic endothelial extracellular matrix
Authors: Han Sewoon , Shin Yoojin , Jeong Hyo Eun , Jeon Jessie S. , Kamm Roger D. , Huh Dongeun , Sohn Lydia L. , Chung Seok 
Published: December 2015

AbstractThe construction of well-controllable in vitro models of physiological and pathological vascular endothelium remains a fundamental challenge in tissue engineering and drug development. Here, we present an approach for forming a synthetic endothelial extracellular matrix (ECM) that closely resembles that of the native structure by locally depositing basement membrane materials onto type 1 collagen nanofibers only in a region adjacent to the endothelial cell (EC) monolayer. Culturing the EC monolayer on this synthetic endothelial ECM remarkably enhanced its physiological properties, reducing its vascular permeability and promoting a stabilized, quiescent phenotype. We demonstrated that the EC monolayer on the synthetic endothelial ECM neither creates non-physiological barriers to cell-cell or cell-ECM interactions, nor hinders molecular diffusion of growth factors and other molecules. The synthetic endothelial ECM and vascular endothelium on it may help us enter in a new phase of research in which various models of the biological barrier behavior can be tested experimentally.
Single-target high-throughput transcription analyses reveal high levels of alternative splicing present in the FPPS/GGPPS from Plasmodium falciparum
Authors: Gabriel Heloisa B. , de Azevedo Mauro F. , Palmisano Giuseppe , Wunderlich Gerhard , Kimura Emília A. , Katzin Alejandro M. , Alves João M. P. 
Published: December 2015

AbstractMalaria is a tropical disease with significant morbidity and mortality. A better understanding of the metabolism of its most important etiological agent, Plasmodium falciparum, is paramount to the development of better treatment and other mitigation measures. Farnesyldiphosphate synthase/geranylgeranyldiphosphate synthase (FPPS/GGPPS) is a key enzyme in the synthesis of isoprenic chains present in many essential structures. In P. falciparum, as well as a handful of other organisms, FPPS/GGPPS has been shown to be a bifunctional enzyme. By genetic tagging and microscopy, we observed a changing localization of FPPS/GGPPS in blood stage parasites. Given the great importance of alternative splicing and other transcriptional phenomena in gene regulation and the generation of protein diversity, we have investigated the processing of the FPPS/GGPPS transcript in P. falciparum by high-throughput sequencing methods in four time-points along the intraerythrocytic cycle of P. falciparum. We have identified levels of transcript diversity an order of magnitude higher than previously observed in this organism, as well as a few stage-specific splicing events. Our data suggest that alternative splicing in P. falciparum is an important feature for gene regulation and the generation of protein diversity.
Characterization and Biotechnological Potential Analysis of a New Exopolysaccharide from the Arctic Marine Bacterium Polaribacter sp. SM1127
Authors: Sun Mei-Ling , Zhao Fang , Shi Mei , Zhang Xi-Ying , Zhou Bai-Cheng , Zhang Yu-Zhong , Chen Xiu-Lan 
Published: December 2015

AbstractAlthough many kinds of exopolysaccharides (EPSs) from microorganisms have been used in industry, the exploration and utilization of EPSs from polar microorganisms is still rather rare. In this study, a flavobacterial strain, SM1127, from the Arctic brown alga Laminaria, was screened for its high EPS production (2.11 g/l) and was identified as belonging to the genus Polaribacter. The EPS secreted by strain SM1127 has a molecular mass of 220 kDa and it mainly comprises N-acetyl glucosamine, mannose and glucuronic acid residues bound by heterogeneous linkages. Rheological studies on the aqueous EPS showed that it had a high viscosity and good shear-thinning property. Moreover, the EPS showed a high tolerance to high salinity and a wide pH range. The EPS also had good antioxidant activity. Particularly, its moisture-retention ability was superior to that of any other reported EPS or functional ingredient generally used in cosmetics. The EPS also showed a protective effect on human dermal fibroblasts at low temperature (4 °C). Safety assessment indicated that the EPS is safe for oral administration and external use. These results indicate the promising potential of the EPS from strain SM1127 in the food, cosmetic, pharmaceutical and biomedical fields.
Engineering Heteromaterials to Control Lithium Ion Transport Pathways
Authors: Liu Yang , Vishniakou Siarhei , Yoo Jinkyoung , Dayeh Shadi A. 
Published: December 2015

AbstractSafe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through the systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation and open new pathways to aid in the development of compact, safe and efficient batteries.
High risk of plant invasion in the understory of eucalypt plantations in South China
Authors: Jin Dongmei , Huang Yong , Zhou Xi-Le , Chen Bin , Ma Jinshuang , Yan Yue-Hong 
Published: December 2015

AbstractEucalypt plantations expand rapidly out of their natural distribution zones, thus inducing a concern on their effects on biodiversity and ecosystem functions. We compare the understory plant diversity of 46 plots of eucalypt plantations, including early and later stages in rotation, with that of 21 plots of contrast vegetation, including other types of plantations and secondary shrub grassland, in Guangdong and Guangxi Provinces, South China. Although the overall plant diversity did not change significantly in eucalypt plantations relative to the contrast vegetation, the community structures changed dramatically. The Asteraceae family, which is the most important source of destructive invasive plant species in China, is ranked 3rd(7.42%) and 7th(3.14%) in species importance in the early and later stages in eucalypt plantations, respectively. Nevertheless, Asteraceae is ranked 15th(1.73%) in other types of plantations and 21st(0.94%) in secondary shrub grassland. Significant increases in the richness and frequency of invasive species were also observed in eucalypt plantations. Among the 20 invasive species recorded in the eucalypt plantations, 9 species were destructive invasive species and 7 of these species belonged to Asteraceae. This study highlights an enhanced plant invasion risk in eucalypt plantations in South China, particularly by Asteraceae.
Sensitivity of proxies on non-linear interactions in the climate system
Authors: Schultz Johannes A. , Beck Christoph , Menz Gunter , Neuwirth Burkhard , Ohlwein Christian , Philipp Andreas 
Published: December 2015

AbstractRecent climate change is affecting the earth system to an unprecedented extent and intensity and has the potential to cause severe ecological and socioeconomic consequences. To understand natural and anthropogenic induced processes, feedbacks, trends and dynamics in the climate system, it is also essential to consider longer timescales. In this context, annually resolved tree-ring data are often used to reconstruct past temperature or precipitation variability as well as atmospheric or oceanic indices such as the North Atlantic Oscillation (NAO) or the Atlantic Multidecadal Oscillation (AMO). The aim of this study is to assess weather-type sensitivity across the Northern Atlantic region based on two tree-ring width networks. Our results indicate that nonstationarities in superordinate space and time scales of the climate system (here synoptic- to global scale, NAO, AMO) can affect the climate sensitivity of tree-rings in subordinate levels of the system (here meso- to synoptic scale, weather-types). This scale bias effect has the capability to impact even large multiproxy networks and the ability of these networks to provide information about past climate conditions. To avoid scale biases in climate reconstructions, interdependencies between the different scales in the climate system must be considered, especially internal ocean/atmosphere dynamics.
From red to green: the propidium iodide-permeable membrane of Shewanella decolorationis S12 is repairable
Authors: Yang Yonggang , Xiang Yinbo , Xu Meiying 
Published: December 2015

AbstractViability is a common issue of concern in almost all microbial processes. Fluorescence-based assays are extensively used in microbial viability assessment, especially for mixed-species samples or biofilms. Propidium iodide (PI) is the most frequently used fluorescence indicator for cell viability based on the membrane permeability. Our results showed that the accumulation of succinate from fumarate respiration could induce PI-permeability in Shewanella decolorationis biofilm cells. Confocal laser scanning microscope further showed that the PI-permeable membrane could be repaired in situ when the extracellular succinate was eliminated by switching fumarate respiration to electrode respiration. Simultaneously with the membrane repair, the electrode respiring capacity of the originally PI-permeable cells was recovered. Agar-colony counts suggested that a major portion of the repaired cells were viable but nonculturable (VBNC). The results evidenced that S. decolorationis S12 has the capacity to repair PI-permeable membranes which suggests a reevaluation of the fate and function of the PI-permeable bacteria and expanded our knowledge on the flexibility of bacterial survival status in harsh environments.
Expression of FABP4, adipsin and adiponectin in Paneth cells is modulated by gut Lactobacillus
Authors: Su Xiaomin , Yan Hui , Huang Yugang , Yun Huan , Zeng Benhua , Wang Enlin , Liu Yu , Zhang Yuan , Liu Feifei , Che Yongzhe , Zhang Zhiqian , Yang Rongcun 
Published: December 2015

AbstractWe here found that intestinal epithelial Paneth cells secrete FABP4, adipsin and adiponectin in both mice and human. Deletion of Paneth cell results in the decrease of FABP4, adipsin and adiponectin not only in intestinal crypt cells but also in sera, suggesting that they may influence the state of the whole body. We also demonstrate that expression of FABP4, adipsin and adiponectin may be modulated by specific gut microbiota. In germ-free (GF) mice, the expression of FABP4, adipsin and adiponectin were lower or difficult to be detected. Feces transplantation promoted the expression of FABP4, adipsin and adiponectin in gut epithelial Paneth cells. We have found that Lactobacillus NK6 colony, which has the highest similarity with Lactobacillus taiwanensis strain BCRC 17755, may induce the expression of FABP4, adipsin and adiponectin through TRAF2 and TRAF6 ubiquitination mediated NF-κB signaling. Taken together, our findings set up a novel mechanism for FABP4, adipsin and adiponectin through gut microbiota mediating expression in gut Paneth cells.
Magnetic field induced flow pattern reversal in a ferrofluidic Taylor-Couette system
Authors: Altmeyer Sebastian , Do Younghae , Lai Ying-Cheng 
Published: December 2015

AbstractWe investigate the dynamics of ferrofluidic wavy vortex flows in the counter-rotating Taylor-Couette system, with a focus on wavy flows with a mixture of the dominant azimuthal modes. Without external magnetic field flows are stable and pro-grade with respect to the rotation of the inner cylinder. More complex behaviors can arise when an axial or a transverse magnetic field is applied. Depending on the direction and strength of the field, multi-stable wavy states and bifurcations can occur. We uncover the phenomenon of flow pattern reversal as the strength of the magnetic field is increased through a critical value. In between the regimes of pro-grade and retrograde flow rotations, standing waves with zero angular velocities can emerge. A striking finding is that, under a transverse magnetic field, a second reversal in the flow pattern direction can occur, where the flow pattern evolves into pro-grade rotation again from a retrograde state. Flow reversal is relevant to intriguing phenomena in nature such as geomagnetic reversal. Our results suggest that, in ferrofluids, flow pattern reversal can be induced by varying a magnetic field in a controlled manner, which can be realized in laboratory experiments with potential applications in the development of modern fluid devices.
Comparative transcriptome analysis of different chemotypes elucidates withanolide biosynthesis pathway from medicinal plant Withania somnifera
Authors: Gupta Parul , Goel Ridhi , Agarwal Aditya Vikram , Asif Mehar Hasan , Sangwan Neelam Singh , Sangwan Rajender Singh , Trivedi Prabodh Kumar 
Published: December 2015

AbstractWithania somnifera is one of the most valuable medicinal plants synthesizing secondary metabolites known as withanolides. Despite pharmaceutical importance, limited information is available about the biosynthesis of withanolides. Chemo-profiling of leaf and root tissues of Withania suggest differences in the content and/or nature of withanolides in different chemotypes. To identify genes involved in chemotype and/or tissue-specific withanolide biosynthesis, we established transcriptomes of leaf and root tissues of distinct chemotypes. Genes encoding enzymes for intermediate steps of terpenoid backbone biosynthesis with their alternatively spliced forms and paralogous have been identified. Analysis suggests differential expression of large number genes among leaf and root tissues of different chemotypes. Study also identified differentially expressing transcripts encoding cytochrome P450s, glycosyltransferases, methyltransferases and transcription factors which might be involved in chemodiversity in Withania. Virus induced gene silencing of the sterol ∆7-reductase (WsDWF5) involved in the synthesis of 24-methylene cholesterol, withanolide backbone, suggests role of this enzyme in biosynthesis of withanolides. Information generated, in this study, provides a rich resource for functional analysis of withanolide-specific genes to elucidate chemotype- as well as tissue-specific withanolide biosynthesis. This genomic resource will also help in development of new tools for functional genomics and breeding in Withania.
PEDOT/PSS-Halloysite Nanotubes (HNTs) Hybrid Films: Insulating HNTs Enhance Conductivity of the PEDOT/PSS Films
Authors: Yan Hu , Zhang Ping , Li Juan , Zhao Xiao-Li , Zhang Ke , Zhang Bing 
Published: December 2015

AbstractWe have for the first time found that completely insulating Halloysite nanotubes (HNTs) significantly enhance electrical conductivity of PEDOT/PSS films by simply mixing. Based on this accident finding we have created highly porous and conductive PEDOT/PSS films hybridized with the HNTs. Through further optimization of the mixing condition we have obtained flexible and conductive hybrid films with high specific surface area. Based on experimental evidences we proposed a plausible mechanism of the phenomenon where the PEDOT/PSS colloidal particle with particle size of several tens nanometers well pack at the nano-channels into well-ordered structures of PEDOT/PSS particles, which show conductivity as higher as several order of magnitude than that of PEDOT/PSS particles in outside of the HNTs.
Responses of community-level plant-insect interactions to climate warming in a meadow steppe
Authors: Zhu Hui , Zou Xuehui , Wang Deli , Wan Shiqiang , Wang Ling , Guo Jixun 
Published: December 2015

AbstractClimate warming may disrupt trophic interactions, consequently influencing ecosystem functioning. Most studies have concentrated on the temperature-effects on plant-insect interactions at individual and population levels, with a particular emphasis on changes in phenology and distribution. Nevertheless, the available evidence from the community level is limited. A 3-year field manipulative experiment was performed to test potential responses of plant and insect communities and plant-insect interactions, to elevated temperature in a meadow steppe. Warming increased the biomass of plant community and forbs and decreased grass biomass, indicating a shift from grass-dominant to grass-forb mixed plant community. Reduced abundance of the insect community under warming, particularly the herbivorous insects, was attributed to lower abundance ofEuchorthippus unicolorand a Cicadellidae species resulting from lower food availability and higher defensive herbivory. Lower herbivore abundance caused lower predator species richness because of reduced prey resources and contributed to an overall decrease in insect species richness. Interestingly, warming enhanced the positive relationship between insect and plant species richness, implying that the strength of the plant-insect interactions was altered by warming. Our results suggest that alterations to plant-insect interactions at a community level under climate warming in grasslands may be more important and complex than previously thought.
Competition between strain and dimensionality effects on the electronic phase transitions in NdNiO3 films
Authors: Wang Le , Ju Sheng , You Lu , Qi Yajun , Guo Yu-wei , Ren Peng , Zhou Yang , Wang Junling 
Published: December 2015

AbstractTransition metal oxides host an array of exotic electronic phases, including superconductivity, ferroelectricity, quantum spin liquid and Mott insulators. Their extreme sensitivity to external stimuli enables various routes to manipulate the ground state, which greatly improves our understanding of the physics involved. Here, we report the competition between strain and dimensionality effects on the phase evolution in high quality NdNiO3 films down to several unit cells. While both compressive and tensile strains increase the Ni 3d band width and favor the metallic phase, reducing dimensionality, on the other hand, decreases the covalent band width and favors the insulating phase in NdNiO3. The experimental observations are well supported by ab initio calculations and improve our understanding of the electronic behavior in strongly correlated electron systems.
Charge-Transfer Induced High Efficient Hydrogen Evolution of MoS2/graphene Cocatalyst
Authors: Li Honglin , Yu Ke , Li Chao , Tang Zheng , Guo Bangjun , Lei Xiang , Fu Hao , Zhu Ziqiang 
Published: December 2015

AbstractThe MoS2 and reduced graphite oxide (rGO) composite has attracted intensive attention due to its favorable performance as hydrogen evolution reaction (HER) catalyst, but still lacking is the theoretical understanding from a dynamic perspective regarding to the influence of electron transfer, as well as the connection between conductivity and the promoted HER performance. Based on the first-principles calculations, we here clearly reveal how an excess of negative charge density affects the variation of Gibbs free energy (ΔG) and the corresponding HER behavior. It is demonstrated that the electron plays a crucial role in the HER routine. To verify the theoretical analyses, the MoS2 and reduced graphite oxide (rGO) composite with well defined 3-dimensional configuration was synthesized via a facile one-step approach for the first time. The experimental data show that the HER performance have a direct link to the conductivity. These findings pave the way for a further developing of 2-dimension based composites for HER applications.