bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverted critical adsorption of polyelectrolytes in confinement
Authors: de Carvalho Sidney J. , Metzler Ralf , Cherstvy Andrey G.
Published: April 2015

What are the fundamental laws for the adsorption of charged polymers onto oppositely charged surfaces, for convex, planar, and concave geometries?
The effect of high external pressure on the structure and stability of MOF α-Mg3(HCOO)6 probed by in situ Raman and FT-IR spectroscopy
Authors: Mao Haiyan , Xu Jun , Hu Yue , Huang Yining , Song Yang
Published: April 2015

A first high-pressure study on MOF α-Mg3(HCOO)6 probed by in situ vibrational spectroscopy revealed strongly contrasting host-dependent structural transitions and stabilities.
Highly efficient photocatalytic conversion of CO2 into solid CO using H2O as a reductant over Ag-modified ZnGa2O4
Authors: Wang Zheng , Teramura Kentaro , Hosokawa Saburo , Tanaka Tsunehiro
Published: April 2015

Highly crystalline ZnGa2O4 modified with Ag particles photocatalytically and selectively converted CO2 into CO (155.0 μmol h−1) using H2O as an electron donor.
Controllable construction of micro/nanostructured NiO arrays in confined microchannels via microfluidic chemical fabrication for highly efficient and specific absorption of abundant proteins
Authors: Zhao De , Wang Gang , He Zhongyuan , Wang Hongzhi , Zhang Qinghong , Li Yaogang
Published: April 2015

The multiple micro/nanostructured NiO arrays constructed on the inner walls of the microchannels via a simple microfluidic chemical method exhibit highly efficient and specific absorption of abundant proteins.
(Et3Si)2Se as a precursor for atomic layer deposition: growth analysis of thermoelectric Bi2Se3
Authors: Sarnet Tiina , Hatanpää Timo , Vehkamäki Marko , Flyktman Timo , Ahopelto Jouni , Mizohata Kenichiro , Ritala Mikko , Leskelä Markku
Published: April 2015

An atomic layer deposition (ALD) process was developed for an important thermoelectric material Bi2Se3utilizing dechlorosilylation reactions between BiCl3and (Et3Si)2Se precursors.
Proteome-wide identification and quantification of S-glutathionylation targets in mouse liver
Authors: McGarry David J. , Chen Wenzhang , Chakravarty Probir , Lamont Douglas L. , Wolf C. Roland , Henderson Colin J.
Published: April 2015

Protein S-glutathionylation is a reversible post-translational modification regulating sulfhydryl homeostasis. However, little is known about the proteins and pathways regulated by S-glutathionylation in whole organisms and current approaches lack the sensitivity to examine this modification under basal conditions. We now report the quantification and identification of S-glutathionylated proteins from animal tissue, using a highly sensitive methodology combining high-accuracy proteomics with tandem mass tagging to provide precise, extensive coverage of S-glutathionylated targets in mouse liver. Critically, we show significant enrichment of S-glutathionylated mitochondrial and Krebs cycle proteins, identifying that S-glutathionylation is heavily involved in energy metabolism processes in vivo. Furthermore, using mice nulled for GST Pi (GSTP) we address the potential for S-glutathionylation to be mediated enzymatically. The data demonstrate the impact of S-glutathionylation in cellular homeostasis, particularly in relation to energy regulation and is of significant interest for those wishing to examine S-glutathionylation in an animal model.
Full length and protease domain activity of chikungunya virus nsP2 differ from other alphavirus nsP2 proteases in recognition of small peptide substrates
Authors: Saisawang Chonticha , Sillapee Pornpan , Sinsirimongkol Kwanhathai , Ubol Sukathida , Smith Duncan R. , Ketterman Albert J.
Published: April 2015

Alphavirus nsP2 proteins are multifunctional and essential for viral replication. The protease role of nsP2 is critical for virus replication as only the virus protease activity is used for processing of the viral non-structural polypeptide. Chikungunya virus is an emerging disease problem that is becoming a world-wide health issue. We have generated purified recombinant chikungunya virus nsP2 proteins, both full length and a truncated protease domain from the C-terminus of the nsP2 protein. Enzyme characterization shows that the protease domain alone has different properties compared with the full length nsP2 protease. We also show chikungunya nsP2 protease possesses different substrate specificity to the canonical alphavirus nsP2 polyprotein cleavage specificity. Moreover, the chikungunya nsP2 also appears to differ from other alphavirus nsP2 in its distinctive ability to recognize small peptide substrates.
Metabolic dysfunction in lymphocytes promotes postoperative morbidity
Authors: Edwards Mark R. , Sultan Pervez , del Arroyo Ana Gutierrez , Whittle John , Karmali Shamir N. , Moonesinghe S. Ramani , Haddad Fares S. , Mythen Michael G. , Singer Mervyn , Ackland Gareth L.
Published: April 2015

Perioperative lymphopenia has been linked with an increased risk of postoperative infectious complications, but the mechanisms remain unclear. We tested the hypothesis that bioenergetic dysfunction is an important mechanism underlying lymphopenia, impaired functionality and infectious complications. In two cohorts of patients (61–82 years old) undergoing orthopaedic joint replacement (n=417 and 328, respectively), we confirmed prospectively that preoperative lymphopenia (≤1.3 x 109·l−1; <20% white cell count; prevalence 15–18%) was associated with infectious complications (relative risk 1.5 (95% confidence interval 1.1–2.0); P=0.008) and prolonged hospital stay. Lymphocyte respirometry, mitochondrial bioenergetics and function were assessed (n=93 patients). Postoperative lymphocytes showed a median 43% fall (range: 26–65%; P=0.029; n=13 patients) in spare respiratory capacity, the extra capacity available to produce energy in response to stress. This was accompanied by reduced glycolytic capacity. A similar hypometabolic phenotype was observed in lymphocytes sampled preoperatively from chronically lymphopenic patients (n=21). This hypometabolic phenotype was associated with functional lymphocyte impairment including reduced T-cell proliferation, lower intracellular cytokine production and excess apoptosis induced by a range of common stressors. Glucocorticoids, which are ubiquitously elevated for a prolonged period postoperatively, generated increased levels of mitochondrial reactive oxygen species, activated caspase-1 and mature interleukin (IL)-1β in human lymphocytes, suggesting inflammasome activation. mRNA transcription of the NLRP1 inflammasome was increased in lymphocytes postoperatively. Genetic ablation of the murine NLRP3 inflammasome failed to prevent glucocorticoid-induced lymphocyte apoptosis and caspase-1 activity, but increased NLRP1 protein expression. Our findings suggest that the hypometabolic phenotype observed in chronically lymphopenic patients and/or acquired postoperatively increases the risk of postoperative infection through glucocorticoid activation of caspase-1 via the NLRP1 inflammasome.
Resource management for interference mitigation in device‐to‐device communication
Authors: Xu Yanli , Liu Yong , Li Dong
Published: April 2015

Resource management issue is studied for device‐to‐device (D2D) communication in cellular networks to improve the overall system capacity and spectrum efficiency. Firstly, a lower bound of the interference distance is derived for a D2D user equipment's according to the transmitter density and the quality of servicerequirement of a D2D pair. By using this distance, an interference set can be chosen adaptively based on the interference condition to guarantee the signal‐to‐interference‐plus‐noise ratio of the D2D pair at a desired probability. Then, the authors propose two resource allocation schemes, the dual metric scheme and the TID (tolerant interference degree) scheme, to mitigate interference among coexistent D2D pairs. The dual metric scheme aims for uniform resource allocation to avoid excess interference in some resources. The TID scheme is designed to guarantee the interference at each D2D pair tolerable. The simulation results show that both the dual metric scheme and the TID scheme achieve more uniform resource allocation at the cost of a negligible increase of resource usage. Compared with the existing schemes such as the random scheme and the freedom degree scheme, the system performance in terms of resource efficiency is significantly improved by two proposed schemes.
Composite right‐/left‐handed coplanar waveguide ferrite forward coupled‐line coupler
Authors: Abdalla Mahmoud Abdelrahman , Hu Zhirun
Published: April 2015

In this study, the authors present a novel compact non‐reciprocal ferrite forward composite right‐/left‐handed (CRLH) coupled‐line coupler (CLC). The proposed forward coupler is realised in coplanar waveguide configuration using series air gap capacitors and shunt planar segment inductors. A theoretical coupled mode analysis of a general non‐ferrite CRLH forward CLC has been proposed. The mode analysis is then extended to ferrite CRLH forward CLC. The ferrite coupler's performance has been further analysed numerically and verified experimentally. Both numerical and experimental results have shown that the coupler demonstrates non‐reciprocal operation for both forward coupling and through propagations. The coupler can achieve ∼10 dB forward coupling and through levels with non‐reciprocity isolation up to 30 dB. Moreover, the coupler has high backward coupling isolation better than 20 dB and very compact size with coupling length = 0.08 λ0 or (0.2 λg) at 8 GHz which is significantly smaller compared with any forward coupler reported to date in the similar operating frequency bands. Although, a conventional ferrite forward CLC can be non‐reciprocal, it has long length, resulting in very high losses. This is not the case for the proposed CRLH coupler. Hence, the novelty and advantage of the coupler are its combined properties in compactness and non‐reciprocity. Furthermore, the coupler requires very low external DC magnetic bias because of its much lower demagnetisation compared with the microstrip configuration.
Multidimensional characterization of stochastic dynamical systems based on multiple perturbations and measurements
Authors: Kryvohuz Maksym , Mukamel Shaul
Published: April 2015

Generalized nonlinear response theory is presented for stochastic dynamical systems. Experiments in which multiple measurements of dynamical quantities are used along with multiple perturbations of parameters of dynamical systems are described by generalized response functions (GRFs). These constitute a new type of multidimensional measures of stochastic dynamics either in the time or the frequency domains. Closed expressions for GRFs in stochastic dynamical systems are derived and compared with numerical non-equilibrium simulations. Several types of perturbations are considered: impulsive and periodic perturbations of temperature and impulsive perturbations of coordinates. The present approach can be used to study various types of stochastic processes ranging from single-molecule conformational dynamics to chemical kinetics of finite-size reactors such as biocells.
Rigidity and soft percolation in the glass transition of an atomistic model of ionic liquid, 1-ethyl-3-methyl imidazolium nitrate, from molecular dynamics simulations—Existence of infinite overlapping networks in a fragile ionic liquid
Authors: Habasaki Junko , Ngai K. L.
Published: April 2015

The typical ionic liquid, 1-ethyl-3-methyl imidazolium nitrate (EMIM-NO3), was examined by molecular dynamics simulations of an all-atomistic model to show the characteristics of networks of cages and/or bonds in the course of vitrification of this fragile glass-former. The system shows changes of dynamics at two characteristic temperatures, TB (or Tc) and the glass transition temperature Tg, found in other fragile glass forming liquids [K. L. Ngai and J. Habasaki, J. Chem. Phys. 141, 114502 (2014)]. On decreasing temperature, the number of neighboring cation-anion pairs, NB, within the first minimum of the pair correlation function, g(r)min, increases. On crossing TB (>Tg), the system volume and diffusion coefficient both show changes in temperature dependence, and as usual at Tg. The glass transition temperature, Tg, is characterized by the saturation of the total number of “bonds,” NB and the corresponding decrease in degree of freedom, F = [(3N − 6) − NB], of the system consisting of N particles. Similar behavior holds for the other ion-ion pairs. Therefore, as an alternative, the dynamics of glass transition can be interpreted conceptually by rigidity percolation. Before saturation occurring at Tg, the number of bonds shows a remarkable change at around TB. This temperature is associated with the disappearance of the loosely packed coordination polyhedra of anions around cation (or vice versa), related to the loss of geometrical freedom of the polyhedra, fg, of each coordination polyhedron, which can be defined by fg = [(3NV − 6) − Nb]. Here, 3Nv is the degree of freedom of NV vertices of the polyhedron, and Nb is number of fictive bonds. The packing of polyhedra is characterized by the soft percolation of cages, which allows further changes with decreasing temperature. The power spectrum of displacement of the central ion in the cage is found to be correlated with the fluctuation of Nb of cation-cation (or anion-anion) pairs in the polyhedron, although the effect from the coordination shells beyond the neighboring ions is not negligible.
Analysis and implementation of a space resolving spherical crystal spectrometer for x-ray Thomson scattering experiments
Authors: Harding E. C. , Ao T. , Bailey J. E. , Loisel G. , Sinars D. B. , Geissel M. , Rochau G. A. , Smith I. C.
Published: April 2015

The application of a space-resolving spectrometer to X-ray Thomson Scattering (XRTS) experiments has the potential to advance the study of warm dense matter. This has motivated the design of a spherical crystal spectrometer, which is a doubly focusing geometry with an overall high sensitivity and the capability of providing high-resolution, space-resolved spectra. A detailed analysis of the image fluence and crystal throughput in this geometry is carried out and analytical estimates of these quantities are presented. This analysis informed the design of a new spectrometer intended for future XRTS experiments on the Z-machine. The new spectrometer collects 6 keV x-rays with a spherically bent Ge (422) crystal and focuses the collected x-rays onto the Rowland circle. The spectrometer was built and then tested with a foam target. The resulting high-quality spectra prove that a spherical spectrometer is a viable diagnostic for XRTS experiments.
Scaling temperature dependent rheology of magnetorheological fluids
Authors: Sherman Stephen G. , Powell Louise A. , Becnel Andrew C. , Wereley Norman M.
Published: April 2015

Magnetorheological (MR) fluids are suspensions of micron-scale magnetizable particles suspended in a carrier fluid. When field is applied, MR fluids develop a field controllable yield stress and a field independent post-yield viscosity. However, this viscosity has substantial temperature dependence, varying by up to an order of magnitude over the operating temperature range of MR fluid devices. We apply non-Brownian suspension theory to explain this result and find that the majority of this effect should be caused by the temperature dependent behavior of the carrier fluid. Thus, if two fluids share the same carrier fluid, then their fluid properties should scale in temperature similarly. This result is first validated by measuring viscosity across temperature for custom model fluids designed to conform to theory, showing temperature scaling within 5% for both the MR fluids and their carrier fluid. Then, on a series of related commercially available fluids with unknown additive content, we show that the MR fluids exhibit common scaling to within 4%. We also investigate the effects of magnetic hysteresis and find that it induces a negligible increase in yield stress and no measurable change in viscosity. We conclude that our non-dimensional analysis enables the temperature dependence of novel MR fluids to be characterized with fewer experiments.
The effect of working gas impurities on plasma jets
Authors: Liu X. Y. , He M. B. , Liu D. W.
Published: April 2015

Air intrusion reduced the purity of working gas inside the tube for plasma jet, and thereby, affected the discharge dynamics. In this paper, the effect of using working gas with different purity level (helium purity 99.99999%, 99.99%, 99.9%, and 99%) on photoionization and the chemical reactivity of plasma jet were studied using a 2 dimensional plasma jet model. Photoionization of air species acted as a source of pre-ionization in front of the ionization region, which facilitated the transition from localized discharge to streamers inside the tube. The density of reactive species inside the tube was found to increase with the concentration of working gas impurities. For the highest purity helium (99.99999%), despite a low photoionization rate and the distance between the photoionization region and ionization region inside the tube, by increasing the applied voltage and decreasing the distance between the electrode and nozzle, plasma jets were formed
First-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groups
Authors: Li Yang , Tu Xingchen , Wang Hao , Sanvito Stefano , Hou Shimin
Published: April 2015

The electronic efficiency and binding energy of contacts formed between graphene electrodes and poly-aromatic hydrocarbon (PAH) anchoring groups have been investigated by the non-equilibrium Green’s function formalism combined with density functional theory. Our calculations show that PAH molecules always bind in the interior and at the edge of graphene in the AB stacking manner, and that the binding energy increases following the increase of the number of carbon and hydrogen atoms constituting the PAH molecule. When we move to analyzing the electronic transport properties of molecular junctions with a six-carbon alkyne chain as the central molecule, the electronic efficiency of the graphene-PAH contacts is found to depend on the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the corresponding PAH anchoring group, rather than its size. To be specific, the smaller is the HOMO-LUMO gap of the PAH anchoring group, the higher is the electronic efficiency of the graphene-PAH contact. Although the HOMO-LUMO gap of a PAH molecule depends on its specific configuration, PAH molecules with similar atomic structures show a decreasing trend for their HOMO-LUMO gap as the number of fused benzene rings increases. Therefore, graphene-conjugated molecule-graphene junctions with high-binding and high-conducting graphene-PAH contacts can be realized by choosing appropriate PAH anchor groups with a large area and a small HOMO-LUMO gap.
The distribution of “time of flight” in three dimensional stationary chaotic advection
Authors: Raynal Florence , Carrière Philippe
Published: April 2015

The distributions of “time of flight” (time spent by a single fluid particle between two crossings of the Poincaré section) are investigated for five different three dimensional stationary chaotic mixers. Above all, we study the large tails of those distributions and show that mainly two types of behaviors are encountered. In the case of slipping walls, as expected, we obtain an exponential decay, which, however, does not scale with the Lyapunov exponent. Using a simple model, we suggest that this decay is related to the negative eigenvalues of the fixed points of the flow. When no-slip walls are considered, as predicted by the model, the behavior is radically different, with a very large tail following a power law with an exponent close to −3.
Interfacial exchange coupling in cubic Heusler Co2FeZ (Z = Al and Si)/tetragonal Mn3Ga bilayers
Authors: Ranjbar R. , Suzuki K. , Sugihara A. , Ma Q. L. , Zhang X. M. , Miyazaki T. , Ando Y. , Mizukami S.
Published: April 2015

We have fabricated bilayer films of tetragonal Heusler-like D022 Mn3Ga and cubic Heusler Co2FeZ (Z = Si and Al) on (100) single-crystalline MgO substrates and investigated their structural and interfacial exchange coupling. The coupling in the Mn3Ga/Co2FeAl bilayer was either ferromagnetic or antiferromagnetic, depending on annealing temperature, whereas only antiferromagnetic exchange coupling was observed in the Mn3Ga/Co2FeSi bilayers. The effects of annealing on the structure and coupling strength in the bilayers are discussed.
Characterization of fluids via measurement of the rotational dynamics of suspended magnetic microdiscs
Authors: Garraud Nicolas , Arnold David P.
Published: April 2015

This paper proposes, analyzes, and demonstrates a method to characterize fluids by monitoring the rotational dynamics of 2.5-μm-diameter magnetic microdiscs in suspension via optical interrogation. The free-floating discs function like synchronized micro-shutters when actuated by an external magnetic field. Their motion is monitored via light transmission in response to a rotating magnetic field. The disc rotation is found, both theoretically and experimentally, to depend on the amplitude and the rotation frequency of the applied magnetic field with a high sensitivity to fluid viscosity changes from 1 to 2 mPa s, independent of the disc concentration in the solution from 20 to 120 M/ml. Consequently, the discs can function as microsensors via simple optical measurements.
Magnetocaloric and thermomagnetic properties of Ni2.18Mn0.82Ga Heusler alloy in high magnetic fields up to 140 kOe
Authors: Kamantsev Alexander P. , Koledov Victor V. , Mashirov Alexey V. , Dilmieva Elvina T. , Shavrov Vladimir G. , Cwik Jacek , Los Anton S. , Nizhankovskii Victor I. , Rogacki Krzysztof , Tereshina Irina S. , Koshkid'ko Yuriy S. , Lyange Maria V. , Khovaylo Vladimir V. , Ari-Gur Pnina
Published: April 2015

Measurements of the adiabatic temperature change (ΔT) and the specific heat transfer (ΔQ) of Ni2.18Mn0.82Ga Heusler alloy were taken in order to quantify the direct giant magnetocaloric effect of the alloy when it is in the vicinity of magneto-structural phase transition (PT) from paramagnetic austenite to ferromagnetic martensite, and their results are presented. A new vacuum calorimeter was used to simultaneously measure ΔT and ΔQ of magnetocaloric materials with a Bitter coil magnet in fields of up to H = 140 kOe. Other thermomagnetic properties of this alloy were investigated using standard differential scanning calorimetry and PPMS equipment. The maximal values of magnetocaloric effect in H = 140 kOe were found to be ΔT = 8.4 K at initial temperature 340 K and ΔQ = 4900 J/kg at 343 K. Using this direct method, we show that the alloy indeed demonstrates the largest value of ΔQ as compared with previously published results for direct measurements of magnetocaloric materials, even though at 140 kOe the magnetic field-induced magnetostructural PT is still not complete.
2:17-type SmCo quasi-single-crystal high temperature magnets
Authors: Zhang Tianli , Liu Hongyuan , Liu Jinghua , Jiang Chengbao
Published: April 2015

2:17-type SmCo high temperature magnets have drawn lots of attentions for potential applications at 500 °C. Usually, 2:17-type SmCo magnets are prepared by powder metallurgy. In this letter, 2:17-type SmCo quasi-single-crystal magnet of Sm(CobalFe0.1Cu0.1Zr0.033)6.93 with [001] orientation is reported, prepared by zone melting directionally solidification. The domain structure and excellent intrinsic magnetic properties of the quasi-single-crystal magnet are investigated. The quasi-single-crystal magnet exhibits a high performance with coercivity of 3.5 T, remanence of 9.5 kG, and energy density of 21.7 MG Oe at room temperature. The coercivity of 1.1 T at 500 °C is achieved, which is the highest value compared with the previously reported SmCo high temperature magnets.
Laser energy deposition and its dynamic uniformity for direct-drive capsules
Authors: Xu Yan , Wu SiZhong , Zheng WuDi
Published: April 2015

The total laser energy deposition of multi-laser-beam irradiation is not only associated with the dynamic behavior of capsule but also the time-dependent angular distribution of the energy deposition of each beam around its axis. The dynamic behavior of laser energy deposition does not linearly respond to the dynamic behavior of laser irradiation. The laser energy deposition uniformity determines the symmetry of implosion. The dynamic behavior of laser energy deposition non-uniformity in OMEGA for laser with square beam shape intensity profile is investigated. In the case of smaller laser spot, the initial non-uniformity caused by laser beam overlap is very high. The shell asymmetry caused by the high initial laser irradiation non-uniformity is estimated by the extent of distortion of shock front which is not as severe as expected before the shock driven by main pulse arrives. This suggests that the large initial non-uniformity due to smaller laser spot is one of the elements that seed disturbance before the main pulse. The rms of laser energy deposition during the main pulse remains above 2%. Since the intensity of main driving pulse usually is several times higher than that of picket pulses, the non-uniformity in main pulse period may jeopardize the symmetrical implosion. When dynamic behavior of capsule is considered, the influence of beam pointing error, the target positioning error, and beam-to-beam power unbalance is quite different for the case of static capsule.
Large electrocaloric effect in Ba(Ti1−xSnx)O3 ceramics over a broad temperature region
Authors: Zhang X. , Wu L. , Gao S. , Liu J. Q. , Xu B. , Xia Y. D. , Yin J. , Liu Z. G.
Published: April 2015

A large electrocaloric effect (ECE) near room temperature is reported in Sn doped BaTiO3 ceramics. By tuning Ba(Ti1−xSnx)O3 compositions which also exhibit relaxor ferroelectric response to near the invariant critical point, the Ba(Ti1−xSnx)O3 bulk ceramics at x ∼ 0.12 exhibit a large EC coefficient (ΔT/ΔE =0.27*10−6K⋅mV−1) over a 50 K temperature range. In addition to that, the diffuse phase transition is successfully applied to broaden the EC peaks under low electric field. These properties added together indicate a general solution of the electrocaloric materials with high performance for practical cooling applications.
Reduced leakage current and improved ferroelectricity in magneto-electric composite ceramics prepared with microwave assisted radiant hybrid sintering
Authors: Upadhyay Sanjay Kumar , Reddy V. Raghavendra , Gupta S. M. , Chauhan N. , Gupta Ajay
Published: April 2015

Structural, electrical and magnetic properties of magneto-electric composite ceramics viz., 0.9 BaTi0.95Sn0.05O3 (BTSO)- 0.1 Ni0.8Zn0.2Fe2O4 (NZFO) prepared with microwave assisted radiant hybrid sintering (MARH) are reported. Phase purity and isovalent substitution of Ti4+ by Sn4+ of the samples is confirmed from x-ray diffraction and 119Sn Mossbauer measurements respectively. Significant suppression of leakage current and improvement of ferroelectricity is observed for the composites prepared with MARH. The observed results are explained in terms of uniform dispersion of ferrite (NZFO) phase in the ferroelectric (BTSO) matrix as evidenced from back-scattered scanning electron micrographs.
An ecological study of the central Queensland ultramafic endemic shrub Neoroepera buxifolia (Picrodendraceae), Australia
Authors: Hendry Rebecca , Wormington Kevin , Walsh Kerry
Published: April 2015

The ultramafic endemic shrub Neoroepera buxifolia Muell.Arg. & F.Muell (Picrodendraceae) has high habitat specificity and is mostly restricted to the perennial and ephemeral creeks and drainage lines of the central Queensland ultramafic landscape. It has an association with high magnesium (Mg) concentrations in the soil and the present study seeks to determine whether there is a correlation between populations of N. buxifolia and the soil extractable Mg and/or Mg : calcium (Ca) quotients in the soil. This was achieved by measuring the standing volume, height and seedling counts of N. buxifolia against the soil elements and other plot characteristics. Whereas correlations were found between increased height of N. buxifolia and the Mg : Ca quotients, soil extractable nickel (Ni) had the greatest influence. The standing volume of N. buxifolia also increased with soil extractable Ni. The standing volume of N. buxifolia was greatest in the upper tributaries of the first-order ephemeral creeks and presence of permanent water of the perennial creeks did not influence the standing volume or height of N. buxfolia.
Biodiversity influences plant productivity through niche–efficiency
Authors: Liang Jingjing , Zhou Mo , Tobin Patrick C. , McGuire A. David , Reich Peter B.
Published: April 2015

Significance

International society has made a commitment to mainstreaming biodiversity conservation into broader socioeconomic development, but an incomplete theoretical basis translates into a lack of practical applications, especially regarding how individual plant productivity changes in response to the overall species loss. In this study, we developed niche–efficiency theory to address two mechanisms behind the effects of biodiversity on individual plant productivity. Supported by empirical evidence at the individual plant level, our theory facilitates adaptive biodiversity management implementation, and the straightforward mathematical formula facilitates the integration of biological conservation in our campaign against pressing global issues. Based on this theory, we developed relative productivity and productivity impact index to provide function-based tools for prioritizing biological conservation efforts.
Maternal Wnt/STOP signaling promotes cell division during early
Xenopus
embryogenesis
Authors: Huang Ya-Lin , Anvarian Zeinab , Döderlein Gabriele , Acebron Sergio P. , Niehrs Christof
Published: April 2015

Significance

Regulation of differential gene expression by Wnt/glycogen synthase kinase 3 (GSK3) signaling plays a major role in development, but there is accumulating evidence for a transcription-independent function of this pathway. In mature oocytes and early embryos, transcription is temporarily silenced, providing an opportunity to study the nontranscriptional role of Wnt signaling. Our study shows that inhibition of Wnt signaling in frog oocytes leads to early cleavage arrest after fertilization and provides evidence that this process occurs by regulating proteins involved in mitosis. Our study indicates that control of early development is a prominent role for nontranscriptional, Wnt/GSK3 signaling.
Dynamic regulation of innate immune responses in
Drosophila
by Senju-mediated glycosylation
Authors: Yamamoto-Hino Miki , Muraoka Masatoshi , Kondo Shu , Ueda Ryu , Okano Hideyuki , Goto Satoshi
Published: April 2015

Significance

The innate immune system is the first line of defense against invading pathogens. Activation of the innate immune response by infection and suppression during steady state are stringently controlled to eliminate pathogens and prevent inflammation. We found that host glycosylation plays an important role in the activation of immune responses and in maintaining innate immune homeostasis. In the steady state, a high amount of galactose-containing glycan suppresses undesirable activation of the immune response; however, activation of immune responses leads to reduced levels of galactose-containing glycan, which is needed for raising immune responses to an adequate level. Our finding suggests a novel mechanism for the regulation of innate immune quiescence and activation via changes in glycosylation status.
Designing multivalent probes for tunable superselective targeting
Authors: Dubacheva Galina V. , Curk Tine , Auzély-Velty Rachel , Frenkel Daan , Richter Ralf P.
Published: April 2015

Significance

A basic requirement in biomedical research is the ability to specifically target cells and tissues. Targeting typically relies on the specific binding of a “ligand” on a tailor-made probe to a “receptor” on the desired cell/tissue. Conventional probes efficiently distinguish a biological entity displaying the receptor from others that do not, but exhibit limited selectivity when the entities to be distinguished display a given receptor at different densities. Multivalent probes that bind several receptors simultaneously potentially can sharply discriminate between different receptor densities. We demonstrate how such “superselective” binding can be tuned through probe design to target a desired receptor density, and thus lay the foundation for the rational design of a new generation of analytical, diagnostic, and therapeutic probes.
Functional and mechanistic studies of XPC DNA-repair complex as transcriptional coactivator in embryonic stem cells
Authors: Cattoglio Claudia , Zhang Elisa T. , Grubisic Ivan , Chiba Kunitoshi , Fong Yick W. , Tjian Robert
Published: April 2015

Significance

Because of their unique ability to self-renew and generate all cell lineages of an organism (pluripotency), embryonic stem cells represent a versatile model for developmental biology, and a promising avenue for regenerative medicine. Understanding the molecular mechanisms regulating self-renewal and pluripotency provides a productive path to effectively use embryonic stem cells, and to improve current methods for induction/differentiation of pluripotent stem cells and direct somatic cell reprogramming. This study provides novel insights into transcriptional regulation of the stem cell state by characterizing interactions between key transcription factors SOX2 and OCT4, and a recently identified, multifunctional, stem cell coactivator—the xeroderma pigmentosum, complementation group C DNA repair complex—to control pluripotency gene-expression networks.
Translocation of Humpback Chub into Tributary Streams of the Colorado River: Implications for Conservation of Large‐River Fishes
Authors: Spurgeon Jonathan J. , Paukert Craig P. , Healy Brian D. , Trammell Melissa , Speas Dave , Omana‐Smith Emily
Published: April 2015

The Humpback Chub Gila cypha, a large‐bodied, endangered cyprinid endemic to the Colorado River basin, is in decline throughout most of its range due largely to anthropogenic factors. Translocation of Humpback Chub into tributaries of the Colorado River is one conservation activity that may contribute to the expansion of the species’ current range and eventually provide population redundancy. We evaluated growth, survival, and dispersal following translocation of approximately 900 Humpback Chub over a period of 3 years (2009, 2010, and 2011) into Shinumo Creek, a tributary stream of the Colorado River within Grand Canyon National Park. Growth and condition of Humpback Chub in Shinumo Creek were consistent among year‐classes and equaled or surpassed growth estimates from both the main‐stem Colorado River and the Little Colorado River, where the largest (and most stable) Humpback Chub aggregation remains. Based on passive integrated tag recoveries, 53% (= 483/902) of translocated Humpback Chub dispersed from Shinumo Creek into the main‐stem Colorado River as of January 2013, 35% leaving within 25 d following translocation. Annual apparent survival estimates within Shinumo Creek ranged from 0.22 to 0.41, but were strongly influenced by emigration. Results indicate that Shinumo Creek provides favorable conditions for growth and survival of translocated Humpback Chub and could support a new population if reproduction and recruitment occur in the future. Adaptation of translocation strategies of Humpback Chub into tributary streams ultimately may refine the role translocation plays in recovery of the species.
Na+/H+ Exchange and Hypoxic Pulmonary Hypertension
Authors: Huetsch John , Shimoda Larissa A.
Published: April 2015

Intracellular pH (pHi) homeostasis is key to the functioning of vascular smooth muscle cells, including pulmonary artery smooth muscle cells (PASMCs). Sodium‐hydrogen exchange (NHE) is an important contributor to pHi control in PASMCs. In this review, we examine the role of NHE in PASMC function, in both physiologic and pathologic conditions. In particular, we focus on the contribution of NHE to the PASMC response to hypoxia, considering both acute hypoxic pulmonary vasoconstriction and the development of pulmonary vascular remodeling and pulmonary hypertension in response to chronic hypoxia. Hypoxic pulmonary hypertension remains a disease with limited therapeutic options. Thus, this review explores past efforts at disrupting NHE signaling and discusses the therapeutic potential that such efforts may have in the field of pulmonary hypertension.
ELMOD2 is anchored to lipid droplets by palmitoylation and regulates adipocyte triglyceride lipase recruitment
Authors: Suzuki Michitaka , Murakami Tatsuro , Cheng Jinglei , Kano Hiroyuki , Fukata Masaki , Fujimoto Toyoshi
Published: April 2015

Adipocyte triglyceride lipase (ATGL) is the major enzyme involved in the hydrolysis of triglycerides. The Arf1–coat protein complex I (COPI) machinery is known to be engaged in the recruitment of ATGL to lipid droplets (LDs), but the regulatory mechanism has not been clarified. In the present study, we found that ELMOD2, a putative noncanonical Arf–GTPase activating protein (GAP) localizing in LDs, plays an important role in controlling ATGL transport to LDs. We showed that knockdown of ELMOD2 by RNA interference induced an increase in the amount of ATGL existing in LDs and decreased the total cellular triglycerides. These effects of ELMOD2 knockdown were canceled by transfection of small interfering RNA-resistant cDNA of wild-type ELMOD2 but not by that of mutated ELMOD2 lacking the Arf-GAP activity. ELMOD2 was distributed in the endoplasmic reticulum and mitochondria as well as in LDs, but palmitoylation was required only for distribution to LDs. An ELMOD2 mutant deficient in palmitoylation failed to reconstitute the ATGL transport after the ELMOD2 knockdown, indicating that distribution in LDs is indispensable to the functionality of ELMOD2. These results indicate that ELMOD2 regulates ATGL transport and cellular lipid metabolism by modulating the Arf1-COPI activity in LDs.
MultiP-SChlo: multi-label protein subchloroplast localization prediction with Chou’s pseudo amino acid composition and a novel multi-label classifier
Authors: Wang Xiao , Zhang Weiwei , Zhang Qiuwen , Li Guo-Zheng
Published: April 2015

Motivation: Identifying protein subchloroplast localization in chloroplast organelle is very helpful for understanding the function of chloroplast proteins. There have existed a few computational prediction methods for protein subchloroplast localization. However, these existing works have ignored proteins with multiple subchloroplast locations when constructing prediction models, so that they can predict only one of all subchloroplast locations of this kind of multilabel proteins.

Results: To address this problem, through utilizing label-specific features and label correlations simultaneously, a novel multilabel classifier was developed for predicting protein subchloroplast location(s) with both single and multiple location sites. As an initial study, the overall accuracy of our proposed algorithm reaches 55.52%, which is quite high to be able to become a promising tool for further studies.

Availability and implementation: An online web server for our proposed algorithm named MultiP-SChlo was developed, which are freely accessible at http://biomed.zzuli.edu.cn/bioinfo/multip-schlo/.

Contact:  pandaxiaoxi@gmail.com or gzli@tongji.edu.cn

Supplementary information:  Supplementary data are available at Bioinformatics online.
Combined Anterior-Posterior Fixation and Fusion for Completely Dislocated Hangman’s Fracture
Authors: Wang Jianxi , Chen Huajiang , Cao Peng , Yuan Wen , Wu Xiaodong , Liu Gang , Li Renhu , Zang Fazhi , Shi Liangyu , Wang An
Published: April 2015

Study Design:

Retrospective clinical study.

Purpose:

To evaluate the effectiveness and feasibility of combined anterior-posterior fixation and fusion for the treatment of completely dislocated hangman’s fracture.

Summary of Background Data:

A completely dislocated hangman’s fracture describes the complete anterior displacement of the C2 vertebral body onto the C3 body. This type of fracture is exceptionally unstable, and for which the management is challenging. Specific treatment strategies need to be further clarified.

Methods:

From January 2003 to January 2012, 11 patients with completely dislocated hangman’s fracture underwent combined anterior-posterior fixation and fusion at our institution; an anterior-posterior approach was used in 9 patients, and an anterior-posterior-anterior approach was used in 2 patients. The operative time, hospital duration, neurological improvement, fusion rate, and complications were assessed.

Results:

The operation times of the 2 anterior-posterior-anterior surgeries (165 and 210 min) were longer than the anterior-posterior approach surgeries (mean, 133 min; range: 110–155 min). The average hospital duration was 8.5 days (range: 7.0–13.0 d). Postoperative reduction and solid fusion were achieved in all patients. Neurological status was significantly improved, as the mean Japanese Orthopedic Association (JOA) score significantly increased from a preoperative score of 8.9±1.7 to 14.6±1.6 at the final follow-up (P<0.01). The mean neurological recovery rate was 51%. Moderate postoperative neck pain occurred in 2 patients, which was relieved after 2 months of conservative treatment with oral celecoxib. The mean visual analog scale pain score was 1.4±0.8 at the last assessment. Hoarseness was found after surgery in 1 patient who recovered 1 month later without any treatment. No graft-related or plate-related complications occurred during the entire follow-up period.

Conclusions:

Combined anterior-posterior fixation and fusion is an effective and safe treatment for completely dislocated hangman’s fracture.
Delayed Superficial Migration of Retained Hyaluronic Acid Years Following Periocular Injection
Authors: Chang Jessica R. , Baharestani Samuel , Salek Sherveen S. , Piluek W. Jordan , Eberhart Charles G. , McCulley Timothy J.
Published: April 2015

Cosmetic injection of hyaluronic acid (HA) and other fillers is increasingly common, and the late complications of these relatively new procedures are now coming to medical attention. Three patients with delayed periocular swelling that began years after injection of HA are described, with CT, MRI, and histopathologic characterization. While HA fillers are marketed as having a temporary effect of several months, the authors demonstrate that they may persist in the body for up to 9 years. Unlike most previous reports, there was no inflammatory reaction or encapsulation, simply infiltration into more superficial subcutaneous layers. All cases improved after surgical biopsy and hyaluronidase injections. Delayed periocular swelling after filler injections from several years prior can mimic serious medical conditions. With a detailed history and high index of suspicion, one may avoid a costly and invasive workup.
Periorbital Necrotizing Fasciitis Secondary to Candida parapsilosis and Streptococcus pyogenes
Authors: Zhang Matthew , Chelnis James , Mawn Louise A.
Published: April 2015

Necrotizing fasciitis is most often caused by either polymicrobial bacterial infections or by Gram-positive organisms, such as Streptococcus or Staphylococcus; however, rare cases of fungal necrotizing fasciitis have been reported. Candida parapsilosis is an emerging fungal pathogen. This fungus grows in either a yeast or pseudohyphal form. C. parapsilosis has been reported to cause keratitis, intraocular infection, and seeding of frontalis slings. C. parapsilosis is a commensal of human skin and can be acquired by nosocomial spread. Necrotizing fasciitis due to Candida has rarely been reported, but to date C. parapsilosis has not been identified as the causative organism in necrotizing fasciitis. This is the first documented case of human periocular soft tissue infection by C. parapsilosis, and also the first report providing evidence of mycotic infection in a necrotizing fasciitis concurrently infected by Streptococcus pyogenes.
Coordination of contractility, adhesion and flow in migratingPhysarumamoebae
Authors: Lewis Owen L. , Zhang Shun , Guy Robert D. , del Álamo Juan C.
Published: April 2015

This work examines the relationship between spatio-temporal coordination of intracellular flow and traction stress and the speed of amoeboid locomotion of microplasmodia ofPhysarum polycephalum. We simultaneously perform particle image velocimetry and traction stress microscopy to measure the velocity of cytoplasmic flow and the stresses applied to the substrate by migratingPhysarummicroamoebae. In parallel, we develop a mathematical model of a motile cell which includes forces from the viscous cytosol, a poro-elastic, contractile cytoskeleton and adhesive interactions with the substrate. Our experiments show that flow and traction stress exhibit back-to-front-directed waves with a distinct phase difference. The model demonstrates that the direction and speed of locomotion are determined by this coordination between contraction, flow and adhesion. Using the model, we identify forms of coordination that generate model predictions consistent with experiments. We demonstrate that this coordination produces near optimal migration speed and is insensitive to heterogeneity in substrate adhesiveness. While it is generally thought that amoeboid motility is robust to changes in extracellular geometry and the nature of extracellular adhesion, our results demonstrate that coordination of adhesive forces is essential to producing robust migration.
The pseudo-compartment method for coupling partial differential equation and compartment-based models of diffusion
Authors: Yates Christian A. , Flegg Mark B.
Published: April 2015

Spatial reaction–diffusion models have been employed to describe many emergent phenomena in biological systems. The modelling technique most commonly adopted in the literature implements systems of partial differential equations (PDEs), which assumes there are sufficient densities of particles that a continuum approximation is valid. However, owing to recent advances in computational power, the simulation and therefore postulation, of computationally intensive individual-based models has become a popular way to investigate the effects of noise in reaction–diffusion systems in which regions of low copy numbers exist. The specific stochastic models with which we shall be concerned in this manuscript are referred to as ‘compartment-based’ or ‘on-lattice’. These models are characterized by a discretization of the computational domain into a grid/lattice of ‘compartments’. Within each compartment, particles are assumed to be well mixed and are permitted to react with other particles within their compartment or to transfer between neighbouring compartments. Stochastic models provide accuracy, but at the cost of significant computational resources. For models that have regions of both low and high concentrations, it is often desirable, for reasons of efficiency, to employ coupled multi-scale modelling paradigms. In this work, we develop two hybrid algorithms in which a PDE in one region of the domain is coupled to a compartment-based model in the other. Rather than attempting to balance average fluxes, our algorithms answer a more fundamental question: ‘how are individual particles transported between the vastly different model descriptions?’ First, we present an algorithm derived by carefully redefining the continuous PDE concentration as a probability distribution. While this first algorithm shows very strong convergence to analytical solutions of test problems, it can be cumbersome to simulate. Our second algorithm is a simplified and more efficient implementation of the first, it is derived in the continuum limit over the PDE region alone. We test our hybrid methods for functionality and accuracy in a variety of different scenarios by comparing the averaged simulations with analytical solutions of PDEs for mean concentrations.