bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative assessment of common genetic variations in HLA-DP with hepatitis B virus infection, clearance and hepatocellular carcinoma development
Authors: Yu Lei , Cheng Yi-ju , Cheng Ming-liang , Yao Yu-mei , Zhang Quan , Zhao Xue-ke , Liu Hua-juan , Hu Ya-xin , Mu Mao , Wang Bi , Yang Guo-zhen , Zhu Li-li , Zhang Shuai
Published: October 2015

Hepatitis B virus (HBV) infection is the predominant risk factor for chronic hepatitis B (CHB), liver cirrhosis (LC) and hepatocellular carcinoma (HCC). Recently, genome-wide association studies have identified human leukocyte antigen (HLA)-DP polymorphisms (rs3077 and rs9277535) as a new chronic HBV infection susceptibility locus. Since then, the relationship between HLA-DP polymorphisms and various outcomes of HBV infection has been reported. However, the results have been inconclusive. To derive a more precise estimation of the relationship between HLA-DP polymorphisms and various outcomes of HBV infection, a meta-analysis of 62,050 subjects from 29 case-control studies was performed. We found that rs3077 and rs9277535 in HLA-DP significantly decreased HBV infection risks and increased HBV clearance possibility in a dose-dependent manner. In the subgroup analysis by ethnicity, study design and sample size, significant associations were found for these polymorphisms in almost all comparisons. Meanwhile, haplotype analyses of the two polymorphisms revealed a significant association between the combination of these alleles and HBV infection outcomes. However, no significant results were observed in HCC development. Our results further confirm that genetic variants in the HLA-DP locus are strongly associated with reduced HBV infection and increased the likelihood of spontaneous viral clearance.
Dressed Gain from the Parametrically Amplified Four-Wave Mixing Process in an Atomic Vapor
Authors: Zhang Zhaoyang , Wen Feng , Che Junling , Zhang Dan , Li Changbiao , Zhang Yanpeng , Xiao Min
Published: October 2015

With a forward cone emitting from the strong pump laser in a thermal rubidium atomic vapor, we investigate the non-degenerate parametrically amplified four-wave mixing (PA-FWM) process with dressing effects in a three-level “double-Λ” configuration both theoretically and experimentally. By seeding a weak probe field into the Stokes or anti-Stokes channel of the FWM, the gain processes are generated in the bright twin beams which are called conjugate and probe beams, respectively. However, the strong dressing effect of the pump beam will dramatically affect the gain factors both in the probe and conjugate channels and can inevitably impose an influence on the quantum effects such as entangled degree and the quantum noise reduction between the two channels. We systematically investigate the intensity evolution of the dressed gain processes by manipulating the atomic density, the Rabi frequency and the frequency detuning. Such dressing effects are also visually evidenced by the observation of Autler-Townes splitting of the gain peaks. The investigation can contribute to the development of quantum information processing and quantum communications.
Lipids assist the membrane insertion of a BAM-independent outer membrane protein
Authors: Huysmans Gerard H. M. , Guilvout Ingrid , Chami Mohamed , Nickerson Nicholas N. , Pugsley Anthony P.
Published: October 2015

Like several other large, multimeric bacterial outer membrane proteins (OMPs), the assembly of the Klebsiella oxytoca OMP PulD does not rely on the universally conserved β-barrel assembly machinery (BAM) that catalyses outer membrane insertion. The only other factor known to interact with PulD prior to or during outer membrane targeting and assembly is the cognate chaperone PulS. Here, in vitro translation-transcription coupled PulD folding demonstrated that PulS does not act during the membrane insertion of PulD and engineered in vivo site-specific cross-linking between PulD and PulS showed that PulS binding does not prevent membrane insertion. In vitro folding kinetics revealed that PulD is atypical compared to BAM-dependent OMPs by inserting more rapidly into membranes containing E. coli phospholipids than into membranes containing lecithin. PulD folding was fast in diC14:0-phosphatidylethanolamine liposomes but not diC14:0-phosphatidylglycerol liposomes and in diC18:1-phosphatidylcholine liposomes but not in diC14:1-phosphatidylcholine liposomes. These results suggest that PulD efficiently exploits the membrane composition to complete final steps in insertion and explain how PulD can assemble independently of any protein-assembly machinery. Lipid-assisted assembly in this manner might apply to other large OMPs whose assembly is BAM-independent.
Adeno-associated-virus-mediated transduction of the mammary gland enables sustained production of recombinant proteins in milk
Authors: Wagner Stefan , Thresher Rosemary , Bland Ross , Laible Götz
Published: October 2015

Biopharming for the production of recombinant pharmaceutical proteins in the mammary gland of transgenic animals is an attractive but laborious alternative compared to mammalian cell fermentation. The disadvantage of the lengthy process of genetically modifying an entire animal could be circumvented with somatic transduction of only the mammary epithelium with recombinant, replication-defective viruses. While other viral vectors offer very limited scope for this approach, vectors based on adeno-associated virus (AAV) appear to be ideal candidates because AAV is helper-dependent, does not induce a strong immune response and has no association with disease. Here, we sought to test the suitability of recombinant AAV (rAAV) for biopharming. Using reporter genes, we showed that injected rAAV efficiently transduced mouse mammary cells. When rAAV encoding human myelin basic protein (hMBP) was injected into the mammary glands of mice and rabbits, this resulted in the expression of readily detectable protein levels of up to 0.5 g/L in the milk. Furthermore we demonstrated that production of hMBP persisted over extended periods and that protein expression could be renewed in a subsequent lactation by re-injection of rAAV into a previously injected mouse gland.
Comparison of the functional features of the pump organs of Anopheles sinensis and Aedes togoi
Authors: Ha Young-Ran , Lee Seung-Chul , Seo Seung-Jun , Ryu Jeongeun , Lee Dong-Kyu , Lee Sang-Joon
Published: October 2015

Mosquitoes act as vectors for severe tropical diseases. Mosquito-borne diseases are affected by various factors such as environmental conditions, host body susceptibility and mosquito feeding behavior. Among these factors, feeding behavior is affected by the feeding pump system located inside the mosquito head and also depends on the species of mosquito. Therefore, the 3D morphological structures of the feeding pumps ofAedes togoiandAnopheles sinensiswere comparatively investigated using synchrotron X-ray microscopic computed tomography. In addition, the feeding behaviors of their pumping organs were also investigated using a 2D X-ray micro-imaging technique.An. sinensis, a malarial vector mosquito, had a larger feeding pump volume thanAe. togoiin the static or resting position. Interestingly, the two species of mosquitoes exhibited different feeding behaviors.Ae. togoihad a higher feeding frequency and expansion ratio thanAn. sinensis.Ae. togoialso exhibited F-actin localization more clearly. These distinctive variations in feeding volumes and behaviors provide essential insight into the blood-feeding mechanisms of female mosquitoes as vectors for tropical diseases.
Prognostic value of tumor-infiltrating FoxP3+ regulatory T cells in cancers: a systematic review and meta-analysis
Authors: Shang Bin , Liu Yao , Jiang Shu-juan , Liu Yi
Published: October 2015

The prognostic value of FoxP3+regulatory T cells (Tregs) in cancer remains controversial. We did a meta-analysis to assess the prognostic effect of FoxP3+Treg across different types of cancer and to investigate factors associated with variations in this effect. PubMed, Embase, Cochrane CENTRAL and Scopus were searched to identify eligible studies. In total, we analyzed 76 articles encompassing 17 types of cancer and including 15,512 cancer cases. The overall pooled analysis including all types of cancer suggested FoxP3+Tregs had a significant negative effect on overall survival (OS) (OR 1.46, P < 0.001), but the prognostic effect varied greatly according to tumor site. High FoxP3+Tregs infiltration was significantly associated with shorter OS in the majority of solid tumors studied, including cervical, renal, melanomas and breast cancers,et al; whereas, FoxP3+Tregs were associated with improved survival in colorectal, head and neck and oesophageal cancers. The stratified analysis suggested the molecular subtype and tumor stage significantly influenced the prognostic value of FoxP3+Tregs in certain types of cancer. In conclusion, our meta-analysis suggests that the prognostic role of FoxP3+Tregs was highly influenced by tumor site and was also correlated with the molecular subtype and tumor stage.
Starch: Introduction and Structure–Property Relationships
Authors: Srikaeo Khongsak
Published: October 2015

Starch is a versatile and useful polymer, not only because it is a cheap, natural material but also because of the ease with which its physicochemical properties can be altered through various treatments. This chapter provides up-to-date information about starch and its structure–property relationships. The complexes of starch with other components, starch hydrolysis, starch modification methods, industrial production of starches and their uses are also discussed.
Natural Fibre-reinforced Thermoplastic Starch Composites
Authors: Sahari J. , Sapuan S. M. , El-Shekeil Y. A. , Ishak M. R. , Akhtar R.
Published: October 2015

Increasing awareness among the world population of the need to protect the environment has motivated research on agricultural residues. This is due to the abundant sources of agricultural crop wastes that cause handling problems. Agricultural crop residues such as oil palm, pineapple leaf, banana and sugar palm are produced on the scale of billions of tons around the world. They are available in abundance, at low cost, and they are also renewable sources of biomass. Hence natural fibres are potential sources in the design of new green materials associated with polymer matrices. Recently, sugar palm fibre has become the most popular reinforcement material for researchers owing to its high durability. It is important to note that biopolymers that act as a matrix can be produced from the sugar palm tree itself. This chapter reports the preparation of an environmentally friendly composite where the matrix (sugar palm starch) and fibre (sugar palm fibre) are derived from one source, the sugar palm tree. The resulting materials are termed “biocomposites” or “green” composites, and are considered to be totally biodegradable.
The effects of precursors on the morphology and microstructure of potassium sodium niobate nanorods synthesized by molten salt synthesis
Authors: Luo Luying , Chen Chao , Luo Hang , Zhang Ye , Zhou Kechao , Zhang Dou
Published: October 2015

The effects of Nb2O5and K2Nb4O11precursors on the morphology, composition, and piezoelectric properties of potassium sodium niobate (KNN) nanorods were investigated.
The triplet excited state of Bodipy: formation, modulation and application
Authors: Zhao Jianzhang , Xu Kejing , Yang Wenbo , Wang Zhijia , Zhong Fangfang
Published: October 2015

The accessing of the triplet excited state of one of the most popular fluorophores, boron-dipyrromethene (Bodipy), was summarized.
2′-Cyanoethyl thioglycosides: effective nucleophiles for synthesis of (hetero)aryl thioglycosides under the catalysis of Cu
Authors: Yuan Xiaolong , Kou Yazhen , Yu Lan , Zhang Zhan-Xin , Xue Weihua
Published: October 2015

2′-Cyanoethyl thioglycosides are designed and synthesized, which are demonstrated to function as powerful nucleophiles to a wide variety of organic iodides.
Sensitive and selective amplified detection of silver ion based on NEase-aided target recycling
Authors: Zhang Kai , Wang Ke , Zhu Xue , Xie Minhao
Published: October 2015

A new Ag+ detection strategy that can be devised utilizing the advantages of both the nicking endonuclease-assisted signaling amplification (NEASA) method and the label-free architecture of G-quadruplex–hemin complex is reported.
Curcumin intercalated layered double hydroxide nanohybrid as a potential drug delivery system for effective photodynamic therapy in human breast cancer cells
Authors: Khorsandi Khatereh , Hosseinzadeh Reza , Fateh Mohsen
Published: October 2015

Curcumin intercalated layered double hydroxide nanohybrid as a potential drug delivery system has been used for effective photodynamic therapy (PDT) in human breast cancer cells.
Construction of Fe6, Fe8 and Mn8 metallamacrocyclic complexes and magnetic properties
Authors: Li Huijun , Wang Yuan , Cai Hongxin , Xu Zhouqing , Jia Lei , Hou Hongwei
Published: October 2015

Hexanuclear-based 1 and octanuclear metallamacrocycle-based three-dimensional isostructural framework 2 and 3 have been obtained and characterised. Magnetic susceptibility measurements show that the three complexes display antiferromagnetic couplings.
Light-emitting properties of donor–acceptor and donor–acceptor–donor dyes in solution, solid, and aggregated states: structure–property relationship of emission behavior
Authors: Ishi-i Tsutomu , Ikeda Kei , Ogawa Michiaki , Kusakaki Yutarou
Published: October 2015

In a polar aqueous environment, a series of triphenylamine-based donor–acceptor-type dyes showed efficient light emission upon the formation of aggregates.
Highly selective and sensitive fluorescence probe based on thymine-modified carbon dots for Hg2+ and l-cysteine detection
Authors: Xu Hui , Huang Shanshan , Liao Caiyun , Li Yang , Zheng Baozhan , Du Juan , Xiao Dan
Published: October 2015

The as-prepared thymine-modified carbon dots were applied to as a sensor for detecting Hg2+ and l-cysteine with high sensitivity and selectivity.
pH-Sensitive graphene oxide/sodium alginate/polyacrylamide nanocomposite semi-IPN hydrogel with improved mechanical strength
Authors: Zhang Huijuan , Pang Xianjuan , Qi Yuan
Published: October 2015

A pH-sensitive and mechanically strong graphene oxide/sodium alginate/polyacrylamide nanocomposite semi-IPN hydrogel was designed and prepared. The composite semi-IPN hydrogel showed superior mechanical strength and pH-dependent swelling behavior.
Fructose conversion in the presence of Sn(iv) catalysts exhibiting high selectivity to lactic acid
Authors: Barros dos Santos Jailma , José Araújo de Albuquerque Nilson , Lúcia de Paiva e Silva Zanta Carmen , Roberto Meneghetti Mario , Margareti Plentz Meneghetti Simoni
Published: October 2015

The catalytic performance of a series of Sn(iv)-based organometallic complexes in fructose conversion was studied under several reaction conditions, and the conversion, yields, and selectivity measurements of this transformation have been evaluated.
Stabilizing an amorphous V2O5/carbon nanotube paper electrode with conformal TiO2 coating by atomic layer deposition for lithium ion batteries
Authors: Xie Ming , Sun Xiang , Sun Hongtao , Porcelli Tim , George Steven M. , Zhou Yun , Lian Jie
Published: October 2015

Amorphous V2O5 (a-V2O5) thin films were conformally coated onto the surface of hydroxyl (–OH) functionalized multi-walled carbon nanotubes (CNTs) and carbon nanotube (CNT) paper using atomic layer deposition (ALD).
Selective photocatalytic N2 fixation dependent on g-C3N4 induced by nitrogen vacancies
Authors: Dong Guohui , Ho Wingkei , Wang Chuanyi
Published: October 2015

We report for the first time that NV-incorporated g-C3N4 can selectively photoreduce N2 and is free from the interference of other gases.
Compositionally-tunable mechanochemical synthesis of ZnxCo3−xO4 nanoparticles for mesoporous p-type photocathodes
Authors: McCullough Shannon M. , Flynn Cory J. , Mercado Candy C. , Nozik Arthur J. , Cahoon James F.
Published: October 2015

A solid-state mechanochemical synthesis of ZnxCo3−xO4 was developed with highly tunable Zn concentration.
Solitons and chaos of the Klein-Gordon-Zakharov system in a high-frequency plasma
Authors: Zhen Hui-Ling , Tian Bo , Sun Ya , Chai Jun , Wen Xiao-Yong
Published: October 2015

In this paper, we study the Klein-Gordon-Zakharov (KGZ) system, which describes the interaction between the Langmuir wave and ion sound wave in a high-frequency plasma. By means of the Hirota method and symbolic computation, bright and mixed-type soliton solutions are obtained. For the one soliton, amplitude of E is positively related to β2, and that of n is inversely related to β2, while they are both positively related to α, where E refers to the high-frequency part of the electrostatic potential of the electric field raised by the electrons, and n represents the deviation of ion density from its equilibrium, β2 and α are the plasma frequency and ion sound speed, respectively. Head-on interactions between the two bright solitons and two mixed-type ones are respectively displayed. With β2 increasing, the head-on interaction is transformed into an overtaking one. Bright bound-state solitons are investigated, and the interaction period decreases with α increasing. Furthermore, with the external forces Γ1(t) and Γ2(t) introduced, the perturbed KGZ system is studied numerically for its associated chaotic motions. Both the weak and developed chaotic motions can be observed. Γ1(t) and Γ2(t) have different effects on the chaotic motions: the chaotic motion can be weakened by decreasing the amplitude of Γ1(t) or increasing the amplitude and frequency of Γ2(t).
Optimization of a Nucleic Acids united-RESidue 2-Point model (NARES-2P) with a maximum-likelihood approach
Authors: He Yi , Liwo Adam , Scheraga Harold A.
Published: October 2015

Coarse-grained models are useful tools to investigate the structural and thermodynamic properties of biomolecules. They are obtained by merging several atoms into one interaction site. Such simplified models try to capture as much as possible information of the original biomolecular system in all-atom representation but the resulting parameters of these coarse-grained force fields still need further optimization. In this paper, a force field optimization method, which is based on maximum-likelihood fitting of the simulated to the experimental conformational ensembles and least-squares fitting of the simulated to the experimental heat-capacity curves, is applied to optimize the Nucleic Acid united-RESidue 2-point (NARES-2P) model for coarse-grained simulations of nucleic acids recently developed in our laboratory. The optimized NARES-2P force field reproduces the structural and thermodynamic data of small DNA molecules much better than the original force field.
Insight into organic reactions from the direct random phase approximation and its corrections
Authors: Ruzsinszky Adrienn , Zhang Igor Ying , Scheffler Matthias
Published: October 2015

The performance of the random phase approximation (RPA) and beyond-RPA approximations for the treatment of electron correlation is benchmarked on three different molecular test sets. The test sets are chosen to represent three typical sources of error which can contribute to the failure of most density functional approximations in chemical reactions. The first test set (atomization and n-homodesmotic reactions) offers a gradually increasing balance of error from the chemical environment. The second test set (Diels-Alder reaction cycloaddition = DARC) reflects more the effect of weak dispersion interactions in chemical reactions. Finally, the third test set (self-interaction error 11 = SIE11) represents reactions which are exposed to noticeable self-interaction errors. This work seeks to answer whether any one of the many-body approximations considered here successfully addresses all these challenges.
Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations
Authors: Ferreira da Silva F. , Lange E. , Limão-Vieira P. , Jones N. C. , Hoffmann S. V. , Hubin-Franskin M.-J. , Delwiche J. , Brunger M. J. , Neves R. F. C. , Lopes M. C. A. , de Oliveira E. M. , da Costa R. F. , Varella M. T. do N. , Bettega M. H. F. , Blanco F. , García G. , Lima M. A. P. , Jones D. B.
Published: October 2015

The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5–10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.
Higher certainty of the laser-induced damage threshold test with a redistributing data treatment
Authors: Jensen Lars , Mrohs Marius , Gyamfi Mark , Mädebach Heinrich , Ristau Detlev
Published: October 2015

As a consequence of its statistical nature, the measurement of the laser-induced damage threshold holds always risks to over- or underestimate the real threshold value. As one of the established measurement procedures, the results of S-on-1 (and 1-on-1) tests outlined in the corresponding ISO standard 21 254 depend on the amount of data points and their distribution over the fluence scale. With the limited space on a test sample as well as the requirements on test site separation and beam sizes, the amount of data from one test is restricted. This paper reports on a way to treat damage test data in order to reduce the statistical error and therefore measurement uncertainty. Three simple assumptions allow for the assignment of one data point to multiple data bins and therefore virtually increase the available data base.
The high pressure structure and equation of state of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) up to 20 GPa: X-ray diffraction measurements and first principles molecular dynamics simulations
Authors: Stavrou Elissaios , Riad Manaa M. , Zaug Joseph M. , Kuo I-Feng W. , Pagoria Philip F. , Kalkan Bora , Crowhurst Jonathan C. , Armstrong Michael R.
Published: October 2015

Recent theoretical studies of 2,6-diamino-3,5-dinitropyrazine-1-oxide (C4H4N6O5 Lawrence Livermore Molecule No. 105, LLM-105) report unreacted high pressure equations of state that include several structural phase transitions, between 8 and 50 GPa, while one published experimental study reports equation of state (EOS) data up to a pressure of 6 GPa with no observed transition. Here we report the results of a synchrotron-based X-ray diffraction study and also ambient temperature isobaric-isothermal atomistic molecular dynamics simulations of LLM-105 up to 20 GPa. We find that the ambient pressure phase remains stable up to 20 GPa; there is no indication of a pressure induced phase transition. We do find a prominent decrease in b-axis compressibility starting at approximately 13 GPa and attribute the stiffening to a critical length where inter-sheet distance becomes similar to the intermolecular distance within individual sheets. The ambient temperature isothermal equation of state was determined through refinements of measured X-ray diffraction patterns. The pressure-volume data were fit using various EOS models to yield bulk moduli with corresponding pressure derivatives. We find very good agreement between the experimental and theoretically derived EOS.
Chiral assembly of weakly curled hard rods: Effect of steric chirality and polarity
Authors: Wensink H. H. , Morales-Anda L.
Published: October 2015

We theoretically investigate the pitch of lyotropic cholesteric phases composed of slender rods with steric chirality transmitted via a weak helical deformation of the backbone. In this limit, the model is amenable to analytical treatment within Onsager theory and a closed expression for the pitch versus concentration and helical shape can be derived. Within the same framework, we also briefly review the possibility of alternative types of chiral order, such as twist-bend or screw-like nematic phases, finding that cholesteric order dominates for weakly helical distortions. While long-ranged or “soft” chiral forces usually lead to a pitch decreasing linearly with concentration, steric chirality leads to a much steeper decrease of quadratic nature. This reveals a subtle link between the range of chiral intermolecular interaction and the pitch sensitivity with concentration. A much richer dependence on the thermodynamic state is revealed for polar helices where parallel and anti-parallel pair alignments along the local director are no longer equivalent. It is found that weak temperature variations may lead to dramatic changes in the pitch, despite the lyotropic nature of the assembly.
Installation of spectrally selective imaging system in RF negative ion source
Authors: Ikeda K. , Wünderlich D. , Fantz U. , Heinemann B. , Kisaki M. , Nagaoka K. , Nakano H. , Osakabe M. , Tsumori K. , Geng S. , Kaneko O. , Takeiri Y.
Published: October 2015

A spectrally selective imaging system has been installed in the RF negative ion source in the International Thermonuclear Experimental Reactor-relevant negative ion beam test facility ELISE (Extraction from a Large Ion Source Experiment) to investigate distribution of hydrogen Balmer-α emission (Hα) close to the production surface of hydrogen negative ion. We selected a GigE vision camera coupled with an optical band-path filter, which can be controlled remotely using high speed network connection. A distribution of Hα emission near the bias plate has been clearly observed. The same time trend on Hα intensities measured by the imaging diagnostic and the optical emission spectroscopy is confirmed.
Thomson scattering in high-intensity chirped laser pulses
Authors: Holkundkar Amol R. , Harvey Chris , Marklund Mattias
Published: October 2015

We consider the Thomson scattering of an electron in an ultra-intense laser pulse. It is well known that at high laser intensities, the frequency and brilliance of the emitted radiation will be greatly reduced due to the electron losing energy before it reaches the peak field. In this work, we investigate the use of a small frequency chirp in the laser pulse in order to mitigate this effect of radiation reaction. It is found that the introduction of a negative chirp means the electron enters a high frequency region of the field while it still has a large proportion of its original energy. This results in a significant enhancement of the frequency and intensity of the emitted radiation as compared to the case without chirping.
Electrical charging effects on the sliding friction of a model nano-confined ionic liquid
Authors: Capozza R. , Benassi A. , Vanossi A. , Tosatti E.
Published: October 2015

Recent measurements suggest the possibility to exploit ionic liquids (ILs) as smart lubricants for nano-contacts, tuning their tribological and rheological properties by charging the sliding interfaces. Following our earlier theoretical study of charging effects on nanoscale confinement and squeezout of a model IL, we present here molecular dynamics simulations of the frictional and lubrication properties of that model under charging conditions. First, we describe the case when two equally charged plates slide while being held together to a confinement distance of a few molecular layers. The shear sliding stress is found to rise strongly and discontinuously as the number of IL layers decreases stepwise. However, the shear stress shows, within each given number of layers, only a weak dependence upon the precise value of the normal load, a result in agreement with data extracted from recent experiments. We subsequently describe the case of opposite charging of the sliding plates and follow the shear stress when the charging is slowly and adiabatically reversed in the course of time, under fixed load. Despite the fixed load, the number and structure of the confined IL layers change with changing charge, and that in turn drives strong friction variations. The latter involves first of all charging-induced freezing of the IL film, followed by a discharging-induced melting, both made possible by the nanoscale confinement. Another mechanism for charging-induced frictional changes is a shift of the plane of maximum shear from mid-film to the plate-film interface, and vice versa. While these occurrences and results invariably depend upon the parameters of the model IL and upon its specific interaction with the plates, the present study helps identifying a variety of possible behavior, obtained under very simple assumptions, while connecting it to an underlying equilibrium thermodynamics picture.
Neutron spectra from beam-target reactions in dense Z-pinches
Authors: Appelbe B. , Chittenden J.
Published: October 2015

The energy spectrum of neutrons emitted by a range of deuterium and deuterium-tritium Z-pinch devices is investigated computationally using a hybrid kinetic-MHD model. 3D MHD simulations are used to model the implosion, stagnation, and break-up of dense plasma focus devices at currents of 70 kA, 500 kA, and 2 MA and also a 15 MA gas puff. Instabilities in the MHD simulations generate large electric and magnetic fields, which accelerate ions during the stagnation and break-up phases. A kinetic model is used to calculate the trajectories of these ions and the neutron spectra produced due to the interaction of these ions with the background plasma. It is found that these beam-target neutron spectra are sensitive to the electric and magnetic fields at stagnation resulting in significant differences in the spectra emitted by each device. Most notably, magnetization of the accelerated ions causes the beam-target spectra to be isotropic for the gas puff simulations. It is also shown that beam-target spectra can have a peak intensity located at a lower energy than the peak intensity of a thermonuclear spectrum. A number of other differences in the shapes of beam-target and thermonuclear spectra are also observed for each device. Finally, significant differences between the shapes of beam-target DD and DT neutron spectra, due to differences in the reaction cross-sections, are illustrated.
Silver nanoparticles with tunable work functions
Authors: Wang Pangpang , Tanaka Daisuke , Ryuzaki Sou , Araki Shohei , Okamoto Koichi , Tamada Kaoru
Published: October 2015

To improve the efficiencies of electronic devices, materials with variable work functions are required to decrease the energy level differences at the interfaces between working layers. Here, we report a method to obtain silver nanoparticles with tunable work functions, which have the same silver core of 5 nm in diameter and are capped by myristates and 1-octanethoilates self-assembled monolayers, respectively. The silver nanoparticles capped by organic molecules can form a uniform two-dimensional sheet at air-water interface, and the sheet can be transferred on various hydrophobic substrates. The surface potential of the two-dimensional nanoparticle sheet was measured in terms of Kelvin probe force microscopy, and the work function of the sheet was then calculated from the surface potential value by comparing with a reference material. The exchange of the capping molecules results in a work function change of approximately 150–250 meV without affecting their hydrophobicity. We systematically discussed the origin of the work function difference and found it should come mainly from the anchor groups of the ligand molecules. The organic molecule capped nanoparticles with tunable work functions have a potential for the applications in organic electronic devices.
A 350-nm-band GaN/AlGaN multiple-quantum-well laser diode on bulk GaN
Authors: Aoki Yuta , Kuwabara Masakazu , Yamashita Yoji , Takagi Yasufumi , Sugiyama Atsushi , Yoshida Harumasa
Published: October 2015

We have demonstrated the pulsed operation of a 350-nm-band ultraviolet laser diode with a vertical current path. The laser structure was grown on a (0001)-face bulk GaN substrate. The lasing wavelength was 356.6 nm and the peak output power reached to 10 mW from the one side of uncoated facets under pulsed current operation with a pulse duration of 10 ns and a repetition frequency of 5 kHz at room temperature. The GaN substrate is expected to provide a cleaved facet configuration leading to an excellent far-field pattern as well as an advantageous thermal management solution of the devices relative to sapphire substrates. The far-field pattern of actual device on GaN substrate has been improved dramatically compared with distorted one on that of sapphire substrates.
Threshold current reduction and directional emission of deformed microdisk lasers via spatially selective electrical pumping
Authors: Aung Nyan L. , Ge Li , Malik Omer , Türeci Hakan E. , Gmachl Claire F.
Published: October 2015

We report on laser threshold current reduction and directional emission from quadrupole-shaped AlGaInAs microdisk diode lasers by selective electrical pumping. The directional emission results from breaking the 2-fold rotation symmetry of the system by the introduction of a triangle-shaped contact geometry, and the laser threshold reduction results from a small current injection area. Room temperature laser operation is achieved in both pulsed and continuous-wave operation for a microdisk radius of 50 μm and deformation constant of ε = 0.09, with optical output power of more than 8 mW and 3 mW, respectively. Under pulsed operation, the minimum measured threshold current for selectively pumped microlasers is 42 mA, significantly lower than the minimum measured threshold current for uniformly pumped microlasers (58 mA) and standard ridge lasers (80 mA) of the same device size and material.
Dual role of boron in improving electrical performance and device stability of low temperature solution processed ZnO thin film transistors
Authors: Gandla Srinivas , Gollu Sankara Rao , Sharma Ramakant , Sarangi Venkateshwarlu , Gupta Dipti
Published: October 2015

In this paper, we have demonstrated the dual role of boron doping in enhancing the device performance parameters as well as the device stability in low temperatures (200 °C) sol-gel processed ZnO thin film transistors (TFTs). Our studies suggest that boron is able to act as a carrier generator and oxygen vacancy suppressor simultaneously. Boron-doped ZnO TFTs with 8 mol. % of boron concentration demonstrated field-effect mobility value of 1.2 cm2 V−1 s−1 and threshold voltage of 6.2 V, respectively. Further, these devices showed lower shift in threshold voltage during the hysteresis and bias stress measurements as compared to undoped ZnO TFTs.
N,N-Dialkyl-N′-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part XIII. Cleavage and Rearrangement Reactions of Pyrazolo[1,5-b][1,2,4,6]thiatriazine 1,1-Dioxides
Authors: Norman Rebecca E. , Perkins Michael V. , Liepa Andris J. , Francis Craig L.
Published: October 2015

Treatment of pyrazolo[1,5-b][1,2,4,6]thiatriazines 1 with the Vilsmeier–Haack reagent afforded pyrazolo[1,5-a][1,3,5]triazines 5. Reaction of compounds 1 with trifluoroacetic anhydride, dimethyl sulfoxide, and triethylamine afforded 5-dimethylsulfanylidene derivatives 8. The guanidino-pyrazole-sulfonic acid 9 was produced from treatment of compounds 1 with trifluoroacetic acid under anhydrous conditions. Similar treatment in the presence of water afforded the desulfonated pyrazolo-guanidine 6. Reactions of 6 with one-carbon electrophiles provided various 4-substituted pyrazolo[1,5-a][1,3,5]triazines 5. Attempted catalytic hydrogenolysis of N7-benzyl pyrazolo[1,5-b][1,2,4,6]thiatriazines 2 in alcohols led to sulfamates 12 from thiatriazine ring cleavage. Ethyl acetate or tert-butanol as solvent allowed successful debenzylation to provide compounds 1. Aminolysis of compounds 2 gave sulfamides 13. Thermal rearrangement of compounds 2 afforded 6-benzyl-pyrazolo[3,4-e][1,2,4]thiadiazines 14.
Exploring the Catalytic Reactivity of Nickel Phosphine–Phosphite Complexes
Authors: Kampmann Sven S. , Man Nikki Y. T. , McKinley Allan J. , Koutsantonis George A. , Stewart Scott G.
Published: October 2015

In this study, we present an investigation into various nickel phosphite and phosphite–phosphine complexes for use in the Mizoroki–Heck and Suzuki–Miyaura cross-coupling reactions and the ammonia arylation reaction. In these coupling reactions, it was discovered that the Ni[P(OEt)3]4, (dppf)Ni[P(OPh)3]2, and (binap)Ni[P(OPh)3]2 catalysts were the most effective. In addition, an optimisation process for these catalytic systems as well as functional group compatibility are discussed.
Structure and assembly of the mouse ASC inflammasome by combined NMR spectroscopy and cryo-electron microscopy
Authors: Sborgi Lorenzo , Ravotti Francesco , Dandey Venkata P. , Dick Mathias S. , Mazur Adam , Reckel Sina , Chami Mohamed , Scherer Sebastian , Huber Matthias , Böckmann Anja , Egelman Edward H. , Stahlberg Henning , Broz Petr , Meier Beat H. , Hiller Sebastian
Published: October 2015

Significance

Invading pathogens and other danger-associated signals are recognized by the innate immune system. Subsequently, the eukaryotic protein ASC [apoptosis-associated speck-like protein containing a caspase-recruitment domain (CARD)] assembles to long filaments, which might serve to amplify the signal and activate an inflammatory response. We have determined the structure of the mouse ASC filament at atomic resolution. The pyrin domain of ASC forms the helical filament core, and the CARD, thus far elusive to experimental observation, is flexibly unfolded on the filament periphery. The integration of data from two structural methods, cryo-electron microscopy and solid-state NMR spectroscopy, opens perspectives for structural studies of inflammasomes and related molecular assemblies.
Whole-agent selectivity within the macaque face-processing system
Authors: Fisher Clark , Freiwald Winrich A.
Published: October 2015

Significance

From the ever-changing patterns of light captured by the eyes, our brains construct a meaningful model of the world. Although we do not know the mechanisms that accomplish this feat, important clues are provided by a series of areas in the primate brain called face patches, which take visual inputs and sequentially process information to extract facial identity. This system is widely considered to be specialized exclusively for faces. However, this study shows that with every processing step, the system increasingly integrates face and body information to represent whole agents. Nearby body patches, in contrast, do not engage in this process. These findings advance our understanding of the neural circuitry that enables the understanding of our social world.
Vitamin B12 deficiency-induced increase of osteoclastic bone resorption caused by abnormal renal resorption of inorganic phosphorus via Napi2a
Authors: Shiga Takahiro , Kimira Yoshifumi , Mano Hiroshi , Kawata Tetsunori , Tadokoro Tadahiro , Suzuki Tsukasa , Yamamoto Yuji
Published: October 2015

Vitamin B12 deficiency is a risk factor for bone disorders via mechanisms not fully understood. In this study, an increase in serum inorganic phosphorus (Pi) concentrations was associated with a vitamin B12 deficiency. Napi2a, a renal cotransporter for Pi reabsorption, accumulated on plasma membranes in a vitamin B12 deficiency suggests that vitamin B12 plays an important role in Pi homeostasis.
Bilateral vs. Multilateral? On the economics and politics of a global mechanism for genetic resource use
Authors: Winands-Kalkuhl Sarah , Holm-Müller Karin
Published: October 2015

Many industries benefit from public biodiversity conservation through the use of genetic resources in R&D processes. The conservation of biodiversity, though, is an under-provided public good. The aim of this paper is to analyze a global mechanism as a policy tool to internalize the positive conservation externalities accruing to commercial users of genetic resources. The United Nations ‘Convention on Biological Diversity’ (CBD) and its ‘Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilisation’ provide a framework for such mechanism. In light of economic arguments in favor of a global mechanism, we study official CBD documents and an online discussion forum launched by the Convention's Secretariat on a global multilateral mechanism, as well as conduct expert interviews with important political stakeholders on genetic resource trade. We find that the economically preferable instrument of a comprehensive global mechanism is politically not feasible any time soon due to path dependencies and an arguably narrow understanding of national sovereignty. Technological progress in genetic resource use, though, might finally induce countries to establish a confined one in the mid-term future. We provide substantiated findings on countries' preferences for its scope and modalities.
Gender and political representation in the de facto states of the Caucasus: women and parliamentary elections in Abkhazia
Authors: Stefańczak Karolina Ó Beacháin , Connolly Eileen
Published: October 2015

This article examines if the reasons suggested for the relatively low percentage of women in parliaments across the former Soviet space can provide an explanation for the low, and deteriorating, percentage of women in the National Assembly of Abkhazia. In the 2012 election women’s representation in the de facto state of Abkhazia dropped from 11.4% to 2.8%, a fall from the highest to the lowest percentage of women in the parliament since 1991 in one election. This result can be explained as a consequence of Abkhazia’s political system, the strong presidency that dominates parliament, the limitations on the capacity of political parties to contest elections and the majoritarian electoral system that all negatively impact on women’s representation. Its single mandate district electoral system would make the application of gender quotas difficult, but in the case of Abkhazia it is the weak party system that creates additional barrier to promoting women candidates. The limitations on political parties mean that the gatekeeper role exercized by them in other polities is hardly present in Abkhazia and as a result social relations rather than the institutionalized practices within political parties dominate electoral competition at the constituency level to the disadvantage of women.
Recognizing the 35th anniversary of the proposal that snRNPs are involved in splicing
Authors: Mount Stephen M. , Wolin Sandra L.
Published: October 2015

Thirty-five years ago, as young graduate students, we had the pleasure and privilege of being in Joan Steitz’s laboratory at a pivotal point in the history of RNA molecular biology. Introns had recently been discovered in the laboratories of Philip Sharp and Richard Roberts, but the machinery for removing them from mRNA precursors was entirely unknown. This Retrospective describes our hypothesis that recently discovered snRNPs functioned in pre-mRNA splicing. The proposal was proven correct, as has Joan’s intuition that small RNAs provide specificity to RNA processing reactions through base pairing in diverse settings. However, research over the intervening years has revealed that both splice site selection and splicing itself are much more complex and dynamic than we imagined.
Sperm motility and fertilisation success in an acidified and hypoxic environment
Authors: Graham Helen , Rastrick Samuel P. S. , Findlay Helen S. , Bentley Matthew G. , Widdicombe Stephen , Clare Anthony S. , Caldwell Gary S.
Published: October 2015

The distribution and function of many marine species is largely determined by the effect of abiotic drivers on their reproduction and early development, including those drivers associated with elevated CO2 and global climate change. A number of studies have therefore investigated the effects of elevated pCO2 on a range of reproductive parameters, including sperm motility and fertilisation success. To date, most of these studies have not examined the possible synergistic effects of other abiotic drivers, such as the increased frequency of hypoxic events that are also associated with climate change. The present study is therefore novel in assessing the impact that an hypoxic event could have on reproduction in a future high CO2 ocean. Specifically, this study assesses sperm motility and fertilisation success in the sea urchin Paracentrotus lividus exposed to elevated pCO2 for 6 months. Gametes extracted from these pre-acclimated individuals were subjected to hypoxic conditions simulating an hypoxic event in a future high CO2 ocean. Sperm swimming speed increased under elevated pCO2 and decreased under hypoxic conditions resulting in the elevated pCO2 and hypoxic treatment being approximately equivalent to the control. There was also a combined negative effect of increased pCO2 and hypoxia on the percentage of motile sperm. There was a significant negative effect of elevated pCO2 on fertilisation success, and when combined with a simulated hypoxic event there was an even greater effect. This could affect cohort recruitment and in turn reduce the density of this ecologically and economically important ecosystem engineer therefore potentially effecting biodiversity and ecosystem services.
Impact of the initial disk mass function on the disk fraction
Authors: Ohsawa Ryou , Onaka Takashi , Yasui Chikako
Published: October 2015

The disk fraction, the percentage of stars with a disk in a young cluster, is widely used to investigate the lifetime of the protoplanetary disk, which can impose an important constraint on the planet formation mechanism. The relationship between the decay timescale of the disk fraction and the mass dissipation timescale of individual disks, however, remains unclear. Here we investigate the effect of the disk mass function (DMF) on the evolution of the disk fraction. We show that the time variation in the disk fraction depends on the spread of the DMF and the detection threshold of the disk. In general, the disk fraction decreases more slowly than the disk mass if a typical initial DMF and a detection threshold are assumed. We find that, if the disk mass decreases exponentially, the mass dissipation timescale of the disk can be as short as 1 Myr even when the disk fraction decreases with a time constant of ∼2.5 Myr. The decay timescale of the disk fraction can be a useful parameter to investigate the disk lifetime, but the difference between the mass dissipation of individual disks and the decrease in the disk fraction should be properly appreciated to estimate the timescale of the disk mass dissipation.