bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma Vitamin B12, Methylmalonic Acid and Heart Rate Variability in Healthy Young Indian Adults
Authors: Sucharita Sambashivaiah , Sowmya Sharma , Thomas Tinku , Kurpad Anura V. , Vaz Mario
Published: May 2014

Prevalence of vitamin B12 deficiency in the Indian population is not known, however; it is considered to be higher than in the Western population. Vitamin B12 deficiency is generally diagnosed by the plasma vitamin B12 level. Metabolites of vitamin B12 such as homocysteine (Hcy) and methylmalonic acid (MMA) are considered to be better markers to diagnose vitamin B12 deficiency at the tissue level. Autonomic neuropathy in vitamin B12 deficiency appears to precede other neurological signs. One of the recent techniques to evaluate autonomic neuropathy is heart rate variability (HRV). We evaluated 14 healthy young adults to explore the association of plasma vitamin B12, MMA, and Hcy levels with HRV. Resting lead II ECG was recorded and power spectral analyses were performed. Plasma MMA level was significantly and negatively correlated with the log-transformed low frequency (r = - 0.74, p = 0.002) and total power spectra (r = - 0.55, p = 0.03) of HRV in absolute units. Low frequency (LF) (r = - 0.56, p = 0.03) and high frequency (HF) (r = 0.57, p = 0.03), when represented in normalized units, were also correlated significantly with plasma MMA. In summary, plasma MMA but not vitamin B12 was significantly associated with HRV indices in a young adult population, suggesting that a tissue-level marker of vitamin B12 deficiency is more closely correlated with functional changes.
HIF1-α-Mediated Gene Expression Induced by Vitamin B1 Deficiency
Authors: Sweet Rebecca L. , Zastre Jason A.
Published: May 2014

It is well established that thiamine deficiency results in an excess of metabolic intermediates such as lactate and pyruvate, which is likely due to insufficient levels of cofactor for the function of thiamine-dependent enzymes. When in excess, both pyruvate and lactate can increase the stabilization of the hypoxia-inducible factor 1-alpha (HIF-1α) transcription factor, resulting in the trans-activation of HIF-1α regulated genes independent of low oxygen, termed pseudo-hypoxia. Therefore, the resulting dysfunction in cellular metabolism and accumulation of pyruvate and lactate during thiamine deficiency may facilitate a pseudo-hypoxic state. In order to investigate the possibility of a transcriptional relationship between hypoxia and thiamine deficiency, we measured alterations in metabolic intermediates, HIF-1α stabilization, and gene expression. We found an increase in intracellular pyruvate and extracellular lactate levels after thiamine deficiency exposure to the neuroblastoma cell line SK-N-BE. Similar to cells exposed to hypoxia, there was a corresponding increase in HIF-1α stabilization and activation of target gene expression during thiamine deficiency, including glucose transporter-1 (GLUT1), vascular endothelial growth factor (VEGF), and aldolase A. Both hypoxia and thiamine deficiency exposure resulted in an increase in the expression of the thiamine transporter SLC19A3. These results indicate thiamine deficiency induces HIF-1α-mediated gene expression similar to that observed in hypoxic stress, and may provide evidence for a central transcriptional response associated with the clinical manifestations of thiamine deficiency.
FUO – alles in Butter?
Authors: Jenni Stefan , Kositz Christian , Diethelm Markus , Albrich Werner
Published: May 2014

Wir stellen den Fall eines 77-jährigen Mannes vor, bei dem ein unklares Fieber auftrat, das trotz detaillierten Abklärungen zunächst unklar blieb. Erst die Serologie brachte am Schluss die Diagnose eines Q-Fiebers. Retrospektiv passen die Anamnese und die Befunde gut zu einem akuten Q-Fieber.
Comparison of Cerebral Blood Flow Acquired by Simultaneous [15O]Water Positron Emission Tomography and Arterial Spin Labeling Magnetic Resonance Imaging
Authors: Zhang Ke , Herzog Hans , Mauler Jörg , Filss Christian , Okell Thomas W , Kops Elena Rota , Tellmann Lutz , Fischer Thomas , Brocke Burkhard , Sturm Walter , Coenen Heinz H , Shah N Jon
Published: May 2014

Until recently, no direct comparison between [15O]water positron emission tomography (PET) and arterial spin labeling (ASL) for measuring cerebral blood flow (CBF) was possible. With the introduction of integrated, hybrid magnetic resonance (MR)-PET scanners, such a comparison becomes feasible. This study presents results of CBF measurements recorded simultaneously with [15O]water and ASL. A 3T MR-BrainPET scanner was used for the simultaneous acquisition of pseudo-continuous ASL (pCASL) magnetic resonance imaging (MRI) and [15O]water PET. Quantitative CBF values were compared in 10 young healthy male volunteers at baseline conditions. A statistically significant ( P<0.05) correlation was observed between the two modalities; the whole-brain CBF values determined with PET and pCASL were 43.3 ±6.1 mL and 51.9 ± 7.1 mL per 100 g per minute, respectively. The gray/white matter (GM/WM) ratio of CBF was 3.0 for PET and 3.4 for pCASL. A paired t-test revealed differences in regional CBF between ASL and PET with higher ASL-CBF than PET-CBF values in cortical areas. Using an integrated, hybrid MR-PET a direct simultaneous comparison between ASL and [15O]water PET became possible for the first time so that temporal, physiologic, and functional variations were avoided. Regional and individual differences were found despite the overall similarity between ASL and PET, requiring further detailed investigations.
Pathogenic potential of interferon αβ in acute influenza infection
Authors: Davidson Sophia , Crotta Stefania , McCabe Teresa M , Wack Andreas
Published: May 2014

Influenza symptoms vary from mild disease to death; however, determinants of severity are unclear. Type I interferons (IFNαβ) are recognized as key antiviral cytokines. Here we show that, surprisingly, influenza-infected 129 mice have increased lung damage, morbidity and mortality, yet higher levels of IFNαβ, than C57BL/6 mice. Consistently, IFNα treatment of influenza-infected C57BL/6 mice increases morbidity. IFNαβ receptor deficiency in 129 mice decreases morbidity, lung damage, proinflammatory cytokines and lung-infiltrating inflammatory cells, and reduces expression of the death-inducing receptor DR5 on lung epithelia and its ligand TRAIL on inflammatory monocytes. Depletion of PDCA-1+ cells or interruption of TRAIL-DR5 interaction protects infected 129 mice. Selective lack of IFNαβ signalling in stromal cells abolishes epithelial DR5 upregulation and apoptosis, reducing host susceptibility. Hence, excessive IFNαβ signalling in response to acute influenza infection can result in uncontrolled inflammation and TRAIL-DR5-mediated epithelial cell death, which may explain morbidity and has important implications for treatment of severe disease.
Model‐Based Meta‐Analysis for Quantifying Paclitaxel Dose Response in Cancer Patients
Authors: Lu D , Joshi A , Li H , Zhang N , Ren MM , Gao Y , Wada R , Jin JY
Published: May 2014

Model‐based meta‐analysis of dose response is a sophisticated method to guide dose and regimen selection. In this report, the effects of paclitaxel dose and regimen (weekly or every 3 weeks) on the efficacy and safety in cancer patients were quantified by model‐based meta‐analysis of 29 monotherapy trials. Logistic regression models were developed to assess the relationship between dose and objective response rate or neutropenia rate. Survival models were developed to assess the relationship between dose and overall survival or progression‐free survival. Paclitaxel efficacy (e.g., objective response rate, median overall survival, and progression‐free survival) is correlated with average dose per week (mg/m2/week), whereas safety (e.g., neutropenia rate) is correlated with dose per administration (mg/m2). Weekly paclitaxel regimen at 65–80 mg/m2 is supported to have comparable to better efficacy and lower neutropenia incidence than an every‐3‐week regimen at 175 mg/m2.

CPT Pharmacometrics Syst. Pharmacol. (2014) 3, e115; doi:10.1038/psp.2014.14; published online 21 May 2014
Copper-catalysed oxidative Csp3–H methylenation to terminal olefins using DMF
Authors: Liu Jianming , Yi Hong , Zhang Xin , Liu Chao , Liu Ren , Zhang Guoting , Lei Aiwen
Published: May 2014

A novel copper-catalysed direct oxidative Csp3–H methylenation to terminal olefins using DMF as one carbon source was developed. In this reaction, various functional groups were well tolerated, thus providing a simple way to construct arylvinylketones and arylvinylpyridines. The preliminary mechanistic investigations revealed that CH2 was from DMF (N–CH3).
Cyclodextrin-based supramolecular nanoparticles stabilized by balancing attractive host–guest and repulsive electrostatic interactions
Authors: Graña Suárez Laura , Verboom Willem , Huskens Jurriaan
Published: May 2014

Multicomponent, negatively charged supramolecular nanoparticles were prepared without the need of a stopper. Their size and stability are controlled owing to a balance of forces between attractive supramolecular and repulsive electrostatic interactions.
Synthesis of very small diameter silica nanofibers using sound waves
Authors: Datskos Panos , Chen Jihua , Sharma Jaswinder
Published: May 2014

Silica nanofibers of an average diameter of 30 nm were synthesized using sound waves.
Fluorine magic: one new organofluorine linker leads to three new metal–organic frameworks
Authors: Peikert K. , Hoffmann F. , Fröba M.
Published: May 2014

2-Fluoro-1,3,5-benzene-tricarboxylic acid (Fbtc) is used as new linker for metal–organic frameworks and leads to three MOFs UHM-31, -32 and -33.
“The Great Beauty” of organolithium chemistry: a land still worth exploring
Authors: Capriati Vito , Perna Filippo M. , Salomone Antonio
Published: May 2014

This Frontier highlights and analyses, from the authors’ perspective, some recent selected contributions from the organolithium field with an eye towards new challenging research directions.
Multicomponent azide–alkyne cycloaddition catalyzed by impregnated bimetallic nickel and copper on magnetite
Authors: Pérez Juana M. , Cano Rafael , Ramón Diego J.
Published: May 2014

Multicomponent azide–alkyne cycloaddition catalyzed by impregnated bimetallic nickel and copper on magnetite.
In situ synthesis, characterization and in vitro studies of ciprofloxacin loaded hydroxyapatite nanoparticles for the treatment of osteomyelitis
Authors: Kumar G. Suresh , Govindan R. , Girija E. K.
Published: May 2014

A series of ciprofloxacin loaded hydroxyapatite nanoparticles has been synthesized by anin situprecipitation method for osteomyelitis treatment.
Squalene mono-oxygenase, a key enzyme in cholesterol synthesis, is stabilized by unsaturated fatty acids
Authors: Stevenson Julian , Luu Winnie , Kristiana Ika , Brown Andrew J.
Published: May 2014

SM (squalene mono-oxygenase) catalyses the first oxygenation step in cholesterol synthesis, immediately before the formation of the steroid backbone at lanosterol. SM is an important control point in the pathway, and is regulated at the post-translational level by accelerated cholesterol-dependent ubiquitination and proteasomal degradation, which is associated with the accumulation of squalene. Using model cell systems, we report that SM is stabilized by unsaturated fatty acids. Treatment with unsaturated fatty acids such as oleate, but not saturated fatty acids, increased protein levels of SM or SM-N100–GFP (the first 100 amino acids of SM fused to GFP) at the post-translational level and partially overcame cholesterol-dependent degradation, as well as reversing cholesterol-dependent squalene accumulation. Maximum stabilization required activation of fatty acids, but not triacylglycerol or phosphatidylcholine synthesis. The mechanism of oleate-mediated stabilization appeared to occur through reduced ubiquitination by the E3 ubiquitin ligase MARCH6. Stabilization of a cholesterol biosynthetic enzyme by unsaturated fatty acids may help maintain a constant cholesterol/phospholipid ratio.
Lysine acetylation: enzymes, bromodomains and links to different diseases
Authors: You Linya , Nie Jianyun , Sun Wei-Jian , Zheng Zhi-Qiang , Yang Xiang-Jiao
Published: May 2014

Lysine acetylation refers to transfer of the acetyl moiety from acetyl-CoA to the ε-amino group of a lysine residue on a protein. This has recently emerged as a major covalent modification and interplays with other modifications, such as phosphorylation, methylation, ubiquitination (addition of a small protein called ubiquitin) and SUMOylation [addition of a ubiquitin-like protein known as SUMO (small ubiquitin-related modifier)], to form multisite modification programmes for cellular regulation in diverse organisms. This modification is post-translational (i.e. after synthesis of a protein) and reversible, with its level being dynamically balanced by two groups of enzymes known as lysine acetyltransferases and deacetylases. The acetyltransferases belong to three major families, whereas deacetylases have been divided into the classical and sirtuin [Sir-tu-in, for Sir2 (silent information regulator 2)-like protein; named after the yeast protein Sir2] families. In addition to these enzymes, proteins containing the bromodomain, a protein module named after the fly protein Brahma (God of creation in Hindu), are relevant to lysine acetylation biology due to their ability to recognize acetyl-lysine-containing peptides. Importantly, recent studies have made intimate links between these three different groups of proteins to different pathological conditions. In this chapter, we provide a brief overview of these proteins and emphasize their direct links to related human diseases.
Mitochondrial protein acetylation regulates metabolism
Authors: Anderson Kristin A. , Hirschey Matthew D.
Published: May 2014

Changes in cellular nutrient availability or energy status induce global changes in mitochondrial protein acetylation. Over one-third of all proteins in the mitochondria are acetylated, of which the majority are involved in some aspect of energy metabolism. Mitochondrial protein acetylation is regulated by SIRT3 (sirtuin 3), a member of the sirtuin family of NAD+-dependent protein deacetylases that has recently been identified as a key modulator of energy homoeostasis. In the absence of SIRT3, mitochondrial proteins become hyperacetylated, have altered function, and contribute to mitochondrial dysfunction. This chapter presents a review of the functional impact of mitochondrial protein acetylation, and its regulation by SIRT3.
Lysine methylation and the regulation of p53
Authors: Carr Simon M. , Munro Shonagh , Thangue Nicholas B. La
Published: May 2014

The p53 tumour suppressor protein functions as a guardian against genotoxic stress. This function is mediated in part by the transcriptional activation of genes involved in cell-cycle arrest, apoptosis, DNA repair and autophagy. The activity of p53 is regulated by a complex array of post-translational modifications, which function as a code to determine cellular responses to a given stress. In this chapter we highlight recent advances in our understanding of this code, with particular reference to lysine methylation, and discuss implications for future research.
High velocity flyer plates launched by magnetic pressure on pulsed power generator CQ-4 and applied in shock Hugoniot experiments
Authors: Zhang Xuping , Wang Guiji , Zhao Jianheng , Tan Fuli , Luo Binqiang , Sun Chengwei
Published: May 2014

High velocity flyer plates with good flatness and some thickness have being widely used to the field of shock physics for characterizations of materials under dynamical loading. The techniques of magnetically driven high-velocity flyer plates are further researched based on our pulsed power generators CQ-4 and some good results got on Sandia's Z machine. With large current of several mega-amperes, the loading surface of electrode panel will suffer acute phase transitions caused from magnetic diffusion and Joule heating, and the thickness and flatness of the flyer plates will change with time. In order to obtain the flyer plates with high performances for shock physics, some researches on electrode panels were done by means of LS-DYNA980 software with electro-magnetic package. Two typical configurations for high velocity flyer plates were compared from distribution uniformity of magnetic field in simulation. The results show that the configuration with counter-bore with “notch” and “ear” is better than the other. Then, with the better configuration panels, some experiments were designed and done to validate the simulation results and obtain high velocity flyer plates with good flatness for one-dimensional strain shock experiments on CQ-4. The velocity profiles of the flyer plates were measured by displacement interferometer systems for any reflectors. And the planarity of flyer plates was measured by using the optical fiber pins array for recording the flyer arrival time. The peak velocities of 8.7 km/s with initial dimension of 10 × 7.2 × 0.62 mm for aluminum flyer plates have been achieved. And the flyer plate with initial size of 12 × 9.2 × 0.73 mm was accelerated to velocity of 6.5 km/s with the flatness of less than 11 ns in the central region of 6 mm in diameter and the effective thickness of about 0.220 mm. Based on these work, the symmetrical impact experiments were performed to obtain the high accuracy Hugoniot data of OFHC (oxygen free high conductance) copper on CQ-4. The experimental results agree well with previous experiment's data given by Mcqueen and Marsh [J. Appl. Phys. 31, 1253 (1960)] and Mitchell and Nellis [J. Appl. Phys. 52, 3363 (1981)], and the experimental uncertainty of shock wave velocity is less than 2.4%.
Laser control of the radiationless decay in pyrazine using the dynamic Stark effect
Authors: Sala Matthieu , Saab Mohamad , Lasorne Benjamin , Gatti Fabien , Guérin Stéphane
Published: May 2014

The laser control of the radiationless decay between the B3u(nπ*) and B2u(ππ*) states of pyrazine using the dynamic Stark effect has been investigated. A vibronic coupling model Hamiltonian in diabatic representation, including potential energy, transition dipole, and static polarizability surfaces as a function of the four most important vibrational modes of the molecule has been parametrized using multi-reference electronic structure calculations. The interaction of the molecule with a strong non-resonant laser pulse has been analyzed in terms of dressed potential energy surfaces. Because of the large polarizability difference between the vibronically coupled B3u(nπ*) and B2u(ππ*) states, the Stark effect induced by the non-resonant laser pulse shifts the conical intersection away from the Franck-Condon region. We have shown, by solving the time-dependent Schrödinger equation for the molecule interacting with a relatively weak pump pulse driving the electronic excitation from the ground state to the B2u(ππ*) state, and a strong non-resonant control pulse, that this control mechanism can be used to trap the wavepacket on the B2u(ππ*) potential energy surface for a much longer time than the natural B2u(ππ*) lifetime.
Simulation of the single-vibronic-level emission spectrum of HPS
Authors: Mok Daniel K. W. , Lee Edmond P. F. , Chau Foo-tim , Dyke John M.
Published: May 2014

We have computed the potential energy surfaces of the ${\rm \tilde X}{}^{\rm 1}{\rm A^\prime }$X̃1A′ and ${\rm \tilde A}{}^{\rm 1}{\rm A^{\prime \prime} }$Ã1A′′ states of HPS using the explicitly correlated multi-reference configuration interaction (MRCI-F12) method, and Franck–Condon factors between the two states, which include anharmonicity and Duschinsky rotation, with the aim of testing the assignment of the recently reported single-vibronic-level (SVL) emission spectrum of HPS [R. Grimminger, D. J. Clouthier, R. Tarroni, Z. Wang, and T. J. Sears, J. Chem. Phys. 139, 174306 (2013)]. These are the highest level calculations on these states yet reported. It is concluded that our spectral simulation supports the assignments of the molecular carrier, the electronic states involved and the vibrational structure of the experimental laser induced fluorescence, and SVL emission spectra proposed by Grimminger et al. [J. Chem. Phys. 139, 174306 (2013)]. However, there remain questions unanswered regarding the relative electronic energies of the two states and the geometry of the excited state of HPS.
Statistical mechanical models for dissociative adsorption of O2 on metal(100) surfaces with blocking, steering, and funneling
Authors: Evans James W. , Liu Da-Jiang
Published: May 2014

We develop statistical mechanical models amenable to analytic treatment for the dissociative adsorption of O2 at hollow sites on fcc(100) metal surfaces. The models incorporate exclusion of nearest-neighbor pairs of adsorbed O. However, corresponding simple site-blocking models, where adsorption requires a large ensemble of available sites, exhibit an anomalously fast initial decrease in sticking. Thus, in addition to blocking, our models also incorporate more facile adsorption via orientational steering and funneling dynamics (features supported by ab initio Molecular Dynamics studies). Behavior for equilibrated adlayers is distinct from those with finite adspecies mobility. We focus on the low-temperature limited-mobility regime where analysis of the associated master equations readily produces exact results for both short- and long-time behavior. Kinetic Monte Carlo simulation is also utilized to provide a more complete picture of behavior. These models capture both the initial decrease and the saturation of the experimentally observed sticking versus coverage, as well as features of non-equilibrium adlayer ordering as assessed by surface-sensitive diffraction.
Backscattering and absorption coefficients for electrons: Solutions of invariant embedding transport equations using a method of convergence
Authors: Figueroa C. , Brizuela H. , Heluani S. P.
Published: May 2014

The backscattering coefficient is a magnitude whose measurement is fundamental for the characterization of materials with techniques that make use of particle beams and particularly when performing microanalysis. In this work, we report the results of an analytic method to calculate the backscattering and absorption coefficients of electrons in similar conditions to those of electron probe microanalysis. Starting on a five level states ladder model in 3D, we deduced a set of integro-differential coupled equations of the coefficients with a method know as invariant embedding. By means of a procedure proposed by authors, called method of convergence, two types of approximate solutions for the set of equations, namely complete and simple solutions, can be obtained. Although the simple solutions were initially proposed as auxiliary forms to solve higher rank equations, they turned out to be also useful for the estimation of the aforementioned coefficients. In previous reports, we have presented results obtained with the complete solutions. In this paper, we present results obtained with the simple solutions of the coefficients, which exhibit a good degree of fit with the experimental data. Both the model and the calculation method presented here can be generalized to other techniques that make use of different sorts of particle beams.
Carbon tetrachloride under extreme conditions
Authors: Pravica Michael , Sneed Daniel , Wang Yonggang , Smith Quinlan , Subrahmanyam Garimella
Published: May 2014

We report on three experiments on carbon tetrachloride subjected to extreme conditions. In the first experiment, Raman spectra of CCl4 were acquired up to 28 GPa. Evidence was observed for at least two new phases of CCl4 above 14 GPa (phase VI) and above 22 GPa (phase VII). Decompression of the sample showed no evidence of pressure-induced decomposition. In the second experiment, a synchrotron x-ray diffraction study was performed up to 30 GPa verifying phase V and potential phases above 14 (VI) and 22 GPa (VII), respectively. In the third study, we examined irradiated CCl4 using synchrotron infrared spectroscopy to reduce fluorescent contamination. Some sort of carbon allotrope appears as a byproduct suggesting the following reaction with hard x-rays: CCl4+ hν → C + 2Cl2.
Accuracy of sample material parameters reconstruction using terahertz pulsed spectroscopy
Authors: Zaytsev Kirill I. , Gavdush Arseniy A. , Karasik Valeriy E. , Alekhnovich Valentin I. , Nosov Pavel A. , Lazarev Vladimir A. , Reshetov Igor V. , Yurchenko Stanislav O.
Published: May 2014

New experimental and theoretical results for the material parameter reconstruction using terahertz (THz) pulsed spectroscopy (TPS) are presented. The material parameter reconstruction algorithm was realized and experimentally implemented to study the test sample. In order to both verify the algorithm and to estimate the reconstruction accuracy, test sample material parameters obtained with the TPS were compared with the results of the same sample studying by the use of the backward-wave oscillator (BWO) spectroscopy. Thus, high reconstruction accuracy was demonstrated for the spectral range, corresponding to the BWO sensitivity and located between 0.2 and 1.2 THz. The numerical simulations were applied for determining the material parameter reconstruction stability in the presence of white Gaussian noise in TPS waveforms as well as fluctuations in the femtosecond (FS) optical pulse duration. We report a strong dependence of the inverse problem solution stability on these factors. We found that the instability of the FS optical pulse duration used for THz pulses generation and detection limits the material parameter reconstruction with TPS.
Development of a cost effective surface-patterned transparent conductive coating as top-contact of light emitting diodes
Authors: Haldar Arpita , Bera Susanta , Jana Sunirmal , Bhattacharya Kallol , Chakraborty Rajib
Published: May 2014

Sol-gel process has been used to form indium zinc oxide films using an optimized combination of zinc to indium concentration in the precursor solutions. Different structures, like one (1D) and two-dimensional (2D) gratings and diffractive optical elements (DOEs) in the form of Fresnel lens are fabricated on the film surface of proposed top metal contact of LED by imprint soft lithography technique. These structures can enhance the LED's light extraction efficiency (LEE) or can shape the output beam pattern, respectively. Several characterizations are done to analyze the material and structural properties of the films. The presence of 1D and 2D gratings as well as DOEs is confirmed from field emission scanning electron and atomic force microscopes analyses. Although, X-ray diffraction shows amorphous nature of the film, but transmission electron microscopy study shows that it is nano crystalline in nature having fine particles (∼8 nm) of hexagonal ZnO. Shrinkage behaviour of gratings as a function of curing temperature is explained by Fourier transform infra-red spectra and thermo gravimetric-differential thermal analysis. The visible transmission and sheet resistance of the sample are found comparable to tin doped indium oxide (ITO). Therefore, the film can compete as low cost substitute of ITO as top metal contact of LEDs.
Scaling of the critical free length for progressive unfolding of self-bonded graphene
Authors: Kwan Kenny , Cranford Steven W.
Published: May 2014

Like filled pasta, rolled or folded graphene can form a large nanocapsule surrounding a hollow interior. Use as a molecular carrier, however, requires understanding of the opening of such vessels. Here, we investigate a monolayer sheet of graphene as a theoretical trial platform for such a nanocapsule. The graphene is bonded to itself via aligned disulfide (S-S) bonds. Through theoretical analysis and atomistic modeling, we probe the critical nonbonded length (free length, Lcrit) that induces fracture-like progressive unfolding as a function of folding radius (Ri). We show a clear linear scaling relationship between the length and radius, which can be used to determine the necessary bond density to predict mechanical opening/closing. However, stochastic dissipated energy limits any exact elastic formulation, and the required energy far exceeds the dissociation energy of the S-S bond. We account for the necessary dissipated kinetic energy through a simple scaling factor (Ω), which agrees well with computational results.
Some characterizations of quantum channel in infinite Hilbert spaces
Authors: Sun Xiu-Hong , Li Yuan
Published: May 2014

We first show that for any quantum states ρ on \documentclass[12pt]{minimal}\begin{document}$\mathcal {H}$\end{document}H and σ on \documentclass[12pt]{minimal}\begin{document}$\mathcal {K}$\end{document}K there exists a quantum channel Φ such that Φ(ρ) = σ, where \documentclass[12pt]{minimal}\begin{document}$\mathcal {H}$\end{document}H and \documentclass[12pt]{minimal}\begin{document}$\mathcal {K}$\end{document}K are finite or infinite dimensional Hilbert spaces. Then we consider some conclusions for the quantum channel Φ such that Φ(ρ) = σ and \documentclass[12pt]{minimal}\begin{document}$\Phi (I_{\mathcal {H}})$\end{document}Φ(IH) exists or \documentclass[12pt]{minimal}\begin{document}$\Phi (I_{\mathcal {H}})=I_{\mathcal {K}}.$\end{document}Φ(IH)=IK.
Array of surface-confined glow discharges in atmospheric pressure helium: Modes and dynamics
Authors: Li D. , Liu D. X. , Nie Q. Y. , Li H. P. , Chen H. L. , Kong M. G.
Published: May 2014

Array of atmospheric pressure surface discharges confined by a two-dimensional hexagon electrode mesh is studied for its discharge modes and temporal evolution so as to a theoretical underpinning to their growing applications in medicine, aerodynamic control, and environmental remediation. Helium plasma surface-confined by one hexagon-shaped rim electrode is shown to evolve from a Townsend mode to a normal and abnormal glow mode, and its evolution develops from the rim electrodes as six individual microdischarges merging in the middle of the hexagon mesh element. Within one hexagon element, microdischarges remain largely static with the mesh electrode being the instantaneous cathode, but move towards the hexagon center when the electrode is the instantaneous anode. On the entire array electrode surface, plasma ignition is found to beat an unspecific hexagon element and then spreads to ignite surrounding hexagon elements. The spreading of microdischarges is in the form of an expanding circle at a speed of about 3 × 104 m/s, and their quenching starts in the location of the initial plasma ignition. Plasma modes influence how input electrical power is used to generate and accelerate electrons and as such the reaction chemistry, whereas plasma dynamics are central to understand and control plasma instabilities. The present study provides an important aspect of plasma physics of the atmospheric surface-confined discharge array and a theoretical underpinning to its future technological innovation.
Spectral dependence of third-order nonlinear optical properties in InN
Authors: Ahn H. , Lee M.-T. , Chang Y.-M.
Published: May 2014

We report on the nonlinear optical properties of InN measured in a wide near-infrared spectral range with the femtosecond Z-scan technique. The above-bandgap nonlinear absorption in InN is found to originate from the saturation of absorption by the band-state-filling and its cross-section increases drastically near the bandgap energy. With below-bandgap excitation, the nonlinear absorption undergoes a transition from saturation absorption (SA) to reverse-SA (RSA), attributed to the competition between SA of band-tail states and two-photon-related RSA. The measured large nonlinear refractive index of the order of 10−10 cm2/W indicates InN as a potential material for all-optical switching and related applications.
A Three-Component 1D/2D → 2D Interpenetrated Coordination Network: Structure and Gas Adsorption Studies
Authors: Chen Jin-Xiang , Ding Ni-Ni , Chen Ming , Chen Wen-Hua , Young David J. , Zhang Wen-Hua , Hor T. S. Andy
Published: May 2014

We herein report a Cd-based coordination polymer containing three integrated polymeric components: two neutral and entangled two-dimensional (6,3) nets and one zwitterionic one-dimensional polymer with corner-sharing double-stranded chains propagating along the c-direction to lock the consecutive ligand struts of the (6,3) nets. Despite a sophisticated entanglement, this coordination polymer is porous to selectively adsorb CO2.
The latitudinal species richness gradient in New World woody angiosperms is consistent with the tropical conservatism hypothesis
Authors: Kerkhoff Andrew J. , Moriarty Pamela E. , Weiser Michael D.
Published: May 2014

Significance

The diversity of living things generally peaks in the tropics and declines toward the poles. This “latitudinal gradient” is Earth’s most prevalent biogeographic pattern, but biologists do not agree about its cause. Here, we use geographic and evolutionary data for over 12,500 species of woody flowering plants to test the “tropical conservatism hypothesis,” which attributes the phenomenal diversity of tropical environments to their large extent over the past 55 million years (My) and the evolutionary conservatism of environmental tolerances. As predicted, we find that transitions between tropical and temperate environments are quite rare over the evolutionary history and that most temperate lineages originated as Earth cooled over the past 34 My. Thus, the correlation between diversity and climate reflects plants’ evolutionary history.
Positive and negative gustatory inputs affect
Drosophila
lifespan partly in parallel to dFOXO signaling
Authors: Ostojic Ivan , Boll Werner , Waterson Michael J. , Chan Tammy , Chandra Rashmi , Pletcher Scott D. , Alcedo Joy
Published: May 2014

Significance

The ability of the worm
Caenorhabditis elegans
to taste or smell can influence its lifespan, and the effect of odors on lifespan has also been shown to exist in the fruit fly
Drosophila
. Now we provide evidence that fly lifespan is also affected by its ability to taste: some taste inputs shorten lifespan, whereas others increase it. In flies, the lifespan-shortening taste inputs act via an insulin-like signaling pathway and its downstream transcription factor dFOXO, whereas the lifespan-lengthening taste inputs can act independently of this pathway. The taste influence on lifespan is also unlikely linked to changes in food intake levels. Thus, different taste inputs will affect lifespan through more than one mechanism.
Acid-sensing ion channel (ASIC) 1a/2a heteromers have a flexible 2:1/1:2 stoichiometry
Authors: Bartoi Tudor , Augustinowski Katrin , Polleichtner Georg , Gründer Stefan , Ulbrich Maximilian H.
Published: May 2014

Significance

Our work concerns the stoichiometry of acid-sensing ion channels (ASICs), proton-gated Na
+
channels. In the central nervous system ASICs are composed of either only ASIC1a subunits or ASIC1a and ASIC2a subunits. Blockade of the ASIC1a/2a heteromer causes strong analgesia. Because ligands and drugs bind at subunit interfaces of ASICs, knowing the exact stoichiometry of heteromeric ASICs is pivotal for an informed drug design. We used a single-molecule method where we image individual ion channels that we fused to fluorescent proteins to clearly demonstrate that ASICs assemble into trimers and that coexpression of ASIC1a and ASIC2a leads to a mix of ASIC1a and ASIC2a homomers and ASIC1a:ASIC2a heteromers. Heteromers assemble randomly in both 1:2 and 2:1 compositions.
Impact of scaffold rigidity on the design and evolution of an artificial Diels-Alderase
Authors: Preiswerk Nathalie , Beck Tobias , Schulz Jessica D. , Milovník Peter , Mayer Clemens , Siegel Justin B. , Baker David , Hilvert Donald
Published: May 2014

Significance

Creating artificial enzymes that catalyze arbitrary chemical reactions is challenging. Although computational approaches to this problem hold great promise, starting designs typically exhibit low efficiency and require extensive optimization through directed evolution. In this study, we chronicle the evolution of a modestly active, computationally designed Diels-Alderase into a proficient biocatalyst for an abiological [4+2] cycloaddition reaction. Biochemical and structural characterization of the evolved enzyme reveals the molecular origins of its enhanced efficiency. The close match between the experimental structure, which changed only subtly over the course of evolution, and the original design model is particularly notable. In addition to enhancing our understanding of the principles of enzymatic catalysis, these findings should aid future efforts to produce active enzymes more reliably.
Linkage disequilibrium and signatures of positive selection around LINE-1 retrotransposons in the human genome
Authors: Kuhn Alexandre , Ong Yao Min , Cheng Ching-Yu , Wong Tien Yin , Quake Stephen R. , Burkholder William F.
Published: May 2014

Significance

LINE-1 (L1) retrotransposons have been shown to mediate various regulatory effects and can affect the transcription of neighboring genes. Thus, novel insertions can potentially result in phenotypic differences that, in turn, could be acted on by selection. We found that a standard Illumina SNP array did not efficiently capture L1s, so that their phenotypic effects might have been missed by previous genome-wide association studies. However, we also found that using whole genome sequencing data, tag SNPs can be identified for a majority of L1s, which opens the way for SNP-based genetic association studies of L1 effects. Moreover, we detected common and unusually long haplotypes around several L1s, which suggests that these insertions might have undergone recent, positive selection in humans.
From the open road to the high seas? Piracy, damnation and resistance in academic consumption of publishing
Authors: Beverungen Armin , Böhm Steffen , Land Christopher
Published: May 2014

Armin Beverungen conducts research on how universities retain their charitable status in a market environment, and on the teaching of ethics in business schools. Steffen Böhm has a particular interest in the economics and management of sustainability. He has also founded an open access journal and an open access press, MayFlyBooks. Christopher Land works on artists and the management of their creativity.
Academic publishing riposte. Do not shoot the messenger
Authors: Stevenson Iain
Published: May 2014

Iain Stevenson is Professor of Publishing and Director Emeritus of the Centre for Publishing at University College London. He has worked in the academic publishing area for many years and has been on the governing board of the Publishers’ Association. Current research is on the history of British publishing, on new publishing technology, and on the experiences of new authors in Britain and France.
Construction and basic characterization of deletion mutants of the genes involved in chitin utilization by Serratia marcescens 2170
Authors: Takanao Shinya , Honma Syouta , Miura Takuma , Ogawa Chisana , Sugimoto Hayuki , Suzuki Kazushi , Watanabe Takeshi
Published: May 2014

In order to elucidate the roles of ChiP, ChiQ, and ChiX in chitin utilization by Serratia marcescens 2170, the construction of single-gene deletion mutants of the chiP, chiQ, and chiX genes was attempted by allelic exchange mutagenesis. ΔchiP formed smaller clearing zones and ΔchiX formed larger ones than wild-type 2170 on an agar plate containing colloidal chitin. ΔchiP grew slowly on the lower concentration of (GlcNAc)2, and there was essentially no growth on chitin oligosaccharides larger than (GlcNAc)3. The gene product of chiP was detected in the outer membrane fraction, consistently with the hypothesis that chiP encodes outer membrane chitoporin. Deletion of chiQ decreased and that of chiX increased the growth rates on chitin oligosaccharides. These observations strongly suggest that all three genes are involved in chitin utilization and that the deletion mutants obtained in this study might prove useful tools to clarify the details of the chitin utilization system of this bacterium.
Histone Deacetylase Inhibition with Trichostatin a does not Reverse Severe Angioproliferative Pulmonary Hypertension in Rats (2013 Grover Conference Series)
Authors: De Raaf Michiel Alexander , Hussaini Aysar Al , Gomez‐Arroyo Jose G. , Kraskaukas Donatas , Farkas Daniela , Happé Chris , Voelkel Norbert F. , Bogaard Harm Jan
Published: May 2014

Pulmonary arterial hypertension (PAH) is a rapidly progressive and devastating disease characterized by remodeling of lung vessels, increased pulmonary vascular resistance, and eventually right ventricular hypertrophy and failure. Because histone deacetylase (HDAC) inhibitors are agents hampering tumor growth and cardiac hypertrophy, they have been attributed a therapeutic potential for patients with PAH. Outcomes of studies evaluating the use of HDAC inhibitors in models of PAH and right ventricular pressure overload have been equivocal, however. Here we describe the levels of HDAC activity in the lungs and hearts of rats with pulmonary hypertension and right heart hypertrophy or failure, experimentally induced by monocrotaline (MCT), the combined exposure to the VEGF‐R inhibitor SU5416 and hypoxia (SuHx), and pulmonary artery banding (PAB). We show that HDAC activity levels are reduced in the lungs of rat with experimentally induced hypertension, whereas activity levels are increased in the hypertrophic hearts. In contrast to what was previously found in the MCT model, the HDAC inhibitor trichostatin A had no effect on pulmonary vascular remodeling in the SuHx model. When our results and those in the published literature are taken together, it is suggested that the effects of HDAC inhibitors in humans with PAH and associated RV failure are, at best, unpredictable. Significant progress can perhaps be made by using more specific HDAC inhibitors, but before clinical tests in human PAH can be undertaken, careful preclinical studies are required to determine potential cardiotoxicity.
Extremal length boundary of the Teichmüller space contains non-Busemann points
Authors: Miyachi Hideki
Published: May 2014

We present an overview of the extremal length embedding of a Teichmüller space and its extremal length compactification. For Teichmüller spaces of dimension at least two, we describe a large class of non-Busemann points on the metric boundary, that is, points that cannot be realized as limits of almost geodesic rays.
Active and Successful Aging: A European Policy Perspective
Authors: Foster Liam , Walker Alan
Published: May 2014

Over the past two decades, “active aging” has emerged in Europe as the foremost policy response to the challenges of population aging. This article examines the concept of active aging and how it differs from that of “successful aging.” In particular, it shows how active aging presents a more holistic, life course–oriented approach than successful aging. We provide a critical perspective on active aging too by, first, tracing its emergence in Europe and then showing how, in practice, it has been dominated by a narrow economic or productivist perspective that prioritizes the extension of working life. It has also been gender blind. Nonetheless, it is argued that an active aging approach has the potential to enable countries to respond successfully to the challenges of population aging because of its comprehensive focus and emphasis on societal as well as individual responsibility. Finally, we set out the basic principles that need to be followed if the full potential of active aging is to be achieved.
The Far-Reaching Implications of the Laval Quartet: The Case of the UK Living Wage
Authors: Koukiadaki Aristea
Published: May 2014

The decisions of the Court of Justice of the European Union (CJEU) in the Laval quartet1 called in question the diversity of labour law rules and industrial relations systems at national level and brought the issue of the interaction between economic freedoms and social rights in the European Union (EU) into political focus.2 While related to the question of labour standards in the case of posted workers, Rüffert has been used to question in some cases the more general issue of the application of Article 56 of the Treaty on the Functioning of the European Union (TFEU) to the inclusion of social and environmental considerations in procurement. Against this context, the paper examines the implications of Rüffert for the UK Living Wage. While the UK government has relied on the CJEU case law to challenge the inclusion of living wage clauses in public procurement, there is evidence of significant consolidation and even further promotion of the Living Wage Campaign. This may be attributed to the concerted efforts of non-judicial actors to respond to the challenges to the campaign following Rüffert3 as well to recent developments in UK procurement law that provide for a more supportive reading of living wage clauses in public procurement.
First Report of Anthracnose of Onion Caused by Colletotrichum coccodes in Ohio
Authors: Baysal-Gurel F. , Subedi N. , Mamiro D. P. , Miller S. A.
Published: May 2014

Dry bulb onion (Allium cepa L. cvs. Pulsar, Bradley, and Livingston) plants with symptoms of anthracnose were observed in three commercial fields totaling 76.5 ha in Huron Co., Ohio, in July 2013. Symptoms were oval leaf lesions and yellowing, curling, twisting, chlorosis, and death of leaves. Nearly half of the plants in a 32.8-ha field of the cv. Pulsar were symptomatic. Concentric rings of acervuli with salmon-colored conidial masses were observed in the lesions. Conidia were straight with tapered ends and 16 to 23 × 3 to 6 μm (2). Colletotrichum coccodes (Wallr.) S. Hughes was regularly isolated from infected plants (2). Culturing diseased leaf tissue on potato dextrose agar (PDA) amended with 30 ppm rifampicin and 100 ppm ampicillin at room temperature yielded white aerial mycelia and salmon-colored conidial masses in acervuli. Numerous spherical, black microsclerotia were produced on the surface of colonies after 10 to 14 days. To confirm pathogen identity, total DNA was extracted directly from a 7-day-old culture of isolate SAM30-13 grown on PDA, using the Wizard SV Genomic DNA Purification System (Promega, Madison, WI) following the manufacturer's instructions. The ribosomal DNA internal transcribed spacer (ITS) region was amplified by PCR using the primer pair ITS1 and ITS4 (2), and sequenced. The sequence, deposited in GenBank (KF894404), was 99% identical to that of a C. coccodes isolate from Michigan (JQ682644) (1). Ten onion seedlings cv. Ebenezer White at the two- to three-leaf stage of growth were spray-inoculated with a conidial suspension (1 × 105 conidia/ml containing 0.01% Tween 20, with 10 ml applied/plant). Plants were maintained in a greenhouse (21 to 23°C) until symptoms appeared. Control plants were sprayed with sterilized water containing 0.01% Tween 20, and maintained in the same environment. After 30 days, sunken, oval lesions each with a salmon-colored center developed on the inoculated plants, and microscopic examination revealed the same pathogen morphology as the original isolates. C. coccodes was re-isolated consistently from leaf lesions. All non-inoculated control plants remained disease-free, and C. coccodes was not re-isolated from leaves of control plants. C. coccodes was reported infecting onions in the United States for the first time in Michigan in 2012 (1). This is the first report of anthracnose of onion caused by C. coccodes in Ohio. Unusually wet, warm conditions in Ohio in 2013 likely contributed to the outbreak of this disease. Timely fungicide applications will be necessary to manage this disease in affected areas.

References: (1) A. K. Lees and A. J. Hilton. Plant Pathol. 52:3. 2003. (2) L. M. Rodriguez-Salamanca et al. Plant Dis. 96:769. 2012. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.