bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep tissue volume imaging of birefringence through fibre-optic needle probes for the delineation of breast tumour
Authors: Villiger Martin , Lorenser Dirk , McLaughlin Robert A. , Quirk Bryden C. , Kirk Rodney W. , Bouma Brett E. , Sampson David D.
Published: July 2016

Identifying tumour margins during breast-conserving surgeries is a persistent challenge. We have previously developed miniature needle probes that could enable intraoperative volume imaging with optical coherence tomography. In many situations, however, scattering contrast alone is insufficient to clearly identify and delineate malignant regions. Additional polarization-sensitive measurements provide the means to assess birefringence, which is elevated in oriented collagen fibres and may offer an intrinsic biomarker to differentiate tumour from benign tissue. Here, we performed polarization-sensitive optical coherence tomography through miniature imaging needles and developed an algorithm to efficiently reconstruct images of the depth-resolved tissue birefringence free of artefacts. First ex vivo imaging of breast tumour samples revealed excellent contrast between lowly birefringent malignant regions, and stromal tissue, which is rich in oriented collagen and exhibits higher birefringence, as confirmed with co-located histology. The ability to clearly differentiate between tumour and uninvolved stroma based on intrinsic contrast could prove decisive for the intraoperative assessment of tumour margins.
Paraoxonase 2 modulates a proapoptotic function in LS174T cells in response to quorum sensing molecule N-(3-oxododecanoyl)-L-homoserine lactone
Authors: Tao Shiyu , Luo Yanwen , Bin He  , Liu Jie , Qian Xi , Ni Yingdong , Zhao Ruqian
Published: July 2016

A mucus layer coats the gastrointestinal tract and serves as the first line of intestinal defense against infection. N-acyl-homoserine lactone (AHL) quorum-sensing molecules produced by gram-negative bacteria in the gut can influence the homeostasis of intestinal epithelium. In this study, we investigated the effects of two representative long- and short-chain AHLs, N-3-(oxododecanoyl)-homoserine lactone (C12-HSL) and N-butyryl homoserine lactone (C4-HSL), on cell viability and mucus secretion in LS174T cells. C12-HSL but not C4-HSL significantly decreased cell viability by inducing mitochondrial dysfunction and activating cell apoptosis which led to a decrease in mucin expression. Pretreatment with lipid raft disruptor (Methyl-β-cyclodextrin, MβCD) and oxidative stress inhibitor (N-acetyl-L-cysteine, NAC) slightly rescued the viability of cells damaged by C12-HSL exposure, while the paraoxonase 2 (PON2) inhibitor (Triazolo[4,3-a]quinolone, TQ416) significantly affected recovering cells viability and mucin secretion. When LS174T cells were treated with C12-HSL and TQ416 simultaneously, TQ416 showed the maximal positive effect on cells viability. However, if cells were first treated with C12-HSL for 40 mins, and then TQ46 was added, the TQ416 had no effect on cell viability. These results suggest that the C12-HSL-acid process acts at an early step to activate apoptosis as part of C12-HSL’s effect on intestinal mucus barrier function.
Involvement of the pagR gene of pXO2 in anthrax pathogenesis
Authors: Liang Xudong , Zhang Enmin , Zhang Huijuan , Wei Jianchun , Li Wei , Zhu Jin , Wang Bingxiang , Dong Shulin
Published: July 2016

Anthrax is a disease caused by Bacillus anthracis. Specifically, the anthrax toxins and capsules encoded by the pXO1 and pXO2 plasmids, respectively, are the major virulence factors. We previously reported that the pXO1 plasmid was retained in the attenuated strain of B. anthracis vaccine strains even after subculturing at high temperatures. In the present study, we reinvestigate the attenuation mechanism of Pasteur II. Sequencing of pXO1 and pXO2 from Pasteur II strain revealed mutations in these plasmids as compared to the reference sequences. Two deletions on these plasmids, one each on pXO1 and pXO2, were confirmed to be unique to the Pasteur II strain as compared to the wild-type strains. Gene replacement with homologous recombination revealed that the mutation in the promoter region of the pagR gene on pXO2, but not the mutation on pXO1, contributes to lethal levels of toxin production. This result was further confirmed by RT-PCR, western blot and animal toxicity assays. Taken together, our results signify that the attenuation of the Pasteur II vaccine strain is caused by a mutation in the pagR gene on its pXO2 plasmid. Moreover, these data suggest that pXO2 plasmid encoded proteins are involved in the virulence of B. anthracis.
Optical gain in GaAsBi/GaAs quantum well diode lasers
Authors: Marko Igor P. , Broderick Christopher A. , Jin Shirong , Ludewig Peter , Stolz Wolfgang , Volz Kerstin , Rorison Judy M. , O’Reilly Eoin P. , Sweeney Stephen J.
Published: July 2016

Electrically pumped GaAsBi/GaAs quantum well lasers are a promising new class of near-infrared devices where, by use of the unusual band structure properties of GaAsBi alloys, it is possible to suppress the dominant energy-consuming Auger recombination and inter-valence band absorption loss mechanisms, which greatly impact upon the device performance. Suppression of these loss mechanisms promises to lead to highly efficient, uncooled operation of telecommunications lasers, making GaAsBi system a strong candidate for the development of next-generation semiconductor lasers. In this report we present the first experimentally measured optical gain, absorption and spontaneous emission spectra for GaAsBi-based quantum well laser structures. We determine internal optical losses of 10–15 cm−1 and a peak modal gain of 24 cm−1, corresponding to a material gain of approximately 1500 cm−1 at a current density of 2 kA cm−2. To complement the experimental studies, a theoretical analysis of the spontaneous emission and optical gain spectra is presented, using a model based upon a 12-band k.p Hamiltonian for GaAsBi alloys. The results of our theoretical calculations are in excellent quantitative agreement with the experimental data and together provide a powerful predictive capability for use in the design and optimisation of high efficiency lasers in the infrared.
Alzheimer’s disease AdvaxCpG- adjuvanted MultiTEP-based dual and single vaccines induce high-titer antibodies against various forms of tau and Aβ pathological molecules
Authors: Davtyan Hayk , Zagorski Karen , Rajapaksha Harinda , Hovakimyan Armine , Davtyan Arpine , Petrushina Irina , Kazarian Konstantin , Cribbs David H. , Petrovsky Nikolai , Agadjanyan Michael G. , Ghochikyan Anahit
Published: July 2016

Although β-amyloid (Aβ) may be the primary driver of Alzheimer’s disease (AD) pathology, accumulation of pathological tau correlates with dementia in AD patients. Thus, the prevention/inhibition of AD may require vaccine/s targeting Aβ and tau simultaneously or sequentially. Since high antibody titers are required for AD vaccine efficacy, we have decided to generate vaccines, targeting Aβ (AV-1959R), Tau (AV-1980R) or Aβ/tau (AV-1953R) B cell epitopes, based on immunogenic MultiTEP platform and evaluate the immunogenicity of these vaccines formulated with AdvaxCpG, delta inulin, Alhydrogel®, Montanide-ISA51, Montanide-ISA720, MPLA-SM pharmaceutical grade adjuvants. Formulation of AV-1959R in AdvaxCpG induced the highest cellular and humoral immune responses in mice. The dual-epitope vaccine, AV-1953R, or the combination of AV-1959R and AV-1980R vaccines formulated with AdvaxCpG induced robust antibody responses against various forms of both, Aβ and tau pathological molecules. While anti-Aβ antibody titers after AV-1953R immunization were similar to that in mice vaccinated with AV-1959R or AV-1959R/AV-1980R combination, anti-tau titers were significantly lower after AV-1953R injection when compared to the AV-1980R or AV-1959R/AV-1980R. In silico 3D-modeling provided insight into the differences in immunogenicity of these vaccine constructs. In sum, AV-1959R and AV-1980R formulated with AdvaxCpG adjuvant were identified as promising immunogenic vaccines for ongoing pre-clinical assessment and future human clinical trials.
miR-2861 acts as a tumor suppressor via targeting EGFR/AKT2/CCND1 pathway in cervical cancer induced by human papillomavirus virus 16 E6
Authors: Xu Junfen , Wan Xiaoyun , Chen Xiaojing , Fang Yifeng , Cheng Xiaodong , Xie Xing , Lu Weiguo
Published: July 2016

Persistent infection with oncogenic human papillomavirus viruses (HPVs) is a casual factor for cervical cancer and its precursors and the abnormal constitutive expression of viral oncoprotein E6 is a key event during the malignant transformation. Here, we performed miRNA microarray to identify changes of miRNAs following ectopic HPV16 E6 overexpression in HEK293T cells and found miR-2861 was greatly decreased in both HEK293T and HaCaT cells expressing HPV16 E6 compared to vector control. Further, we demonstrated a biological link among HPV16 E6, miR-2861, EGFR, AKT2 and CCND1 in cervical cancer cells. We showed that miR-2861 was downregulated in cervical cancer tissues and negatively correlated with advanced tumor stage and lymph node metastasis. Overexpression of miR-2861 suppressed cervical cancer cell proliferation and invasion and enhanced apoptosis. Subsequent investigation revealed that EGFR, AKT2 and CCND1 were all the direct targets of miR-2861. Importantly, silencing EGFR, AKT2, and/or CCND1 recapitulated the cellular effects seen upon miR-2861 overexpression. Restoration of EGFR, AKT2, and/or CCND1 counteracted the effects of miR-2861 expression. Thus, we identified a new pathway employing miR-2861, EGFR, AKT2 and CCND1 that may mediate HPV16 E6 induced initiation and progression of cervical cancer.
Accelerating skin wound healing by M-CSF through generating SSEA-1 and -3 stem cells in the injured sites
Authors: Li Yunyuan , Jalili Reza Baradar , Ghahary Aziz
Published: July 2016

Wound healing is a complicated process requiring the collaborative efforts of different cell lineages. Our recent studies have found that one subset of hematopoietic cells can be induced to dedifferentiate into multipotent stem cells by means of a proliferating fibroblast releasable factor, M-CSF. Understanding the importance of stem cells on skin wound healing, here we evaluate the biological significance of M-CSF on skin wound healing. In anin vivomouse skin excisional wound model, we found that SSEA-positive stem cells were present in wounded but not normal skin. After isolating skin cells from either normal or wounded skin by collagenase digestion and analyzing the SSEA-1 positive cells by flow cytometry, we found a significant increase in the number of SSEA-1 positive cells in wounded skin. Topical application of M-CSF in skin wounds accelerated healing remarkably, while application of M-CSF-neutralizing antibody slowed wound healing. Furthermore, injection of EGFP-labeled hematopoietic cell-derived stem cells generated from M-CSF treated splenocytes resulted in EGFP-labeled cells being enriched in the skin wound site and further differentiated into functional organ-specific cells. Together, these data demonstrated that M-CSF makes a significant contribution to the healing process by inducing hematopoietic cell dedifferentiation into stem cells.
Classification of fracture and non-fracture groups by analysis of coherent X-ray scatter
Authors: Dicken A. J. , Evans J. P. O. , Rogers K. D. , Stone N. , Greenwood C. , Godber S. X. , Clement J. G. , Lyburn I. D. , Martin R. M. , Zioupos P.
Published: July 2016

Osteoporotic fractures present a significant social and economic burden, which is set to rise commensurately with the aging population. Greater understanding of the physicochemical differences between osteoporotic and normal conditions will facilitate the development of diagnostic technologies with increased performance and treatments with increased efficacy. Using coherent X-ray scattering we have evaluated a population of 108 ex vivo human bone samples comprised of non-fracture and fracture groups. Principal component fed linear discriminant analysis was used to develop a classification model to discern each condition resulting in a sensitivity and specificity of 93% and 91%, respectively. Evaluating the coherent X-ray scatter differences from each condition supports the hypothesis that a causal physicochemical change has occurred in the fracture group. This work is a critical step along the path towards developing an in vivo diagnostic tool for fracture risk prediction.
In vivo assessment of behavioral recovery and circulatory exchange in the peritoneal parabiosis model
Authors: Castellano Joseph M. , Palner Mikael , Li Shi-Bin , Freeman G. Mark , Nguyen Andy , Shen Bin , Stan Trisha , Mosher Kira I. , Chin Frederick T. , de Lecea Luis , Luo Jian , Wyss-Coray Tony
Published: July 2016

The sharing of circulation between two animals using a surgical procedure known as parabiosis has created a wealth of information towards our understanding of physiology, most recently in the neuroscience arena. The systemic milieu is a complex reservoir of tissues, immune cells and circulating molecules that is surprisingly not well understood in terms of its communication across organ systems. While the model has been used to probe complex physiological questions for many years, critical parameters of recovery and exchange kinetics remain incompletely characterized, limiting the ability to design experiments and interpret results for complex questions. Here we provide evidence that mice joined by parabiosis gradually recover much physiology relevant to the study of brain function. Specifically, we describe the timecourse for a variety of recovery parameters, including those for general health and metabolism, motor coordination, activity and sleep behavior. Finally, we describe the kinetics of chimerism for several lymphocyte populations as well as the uptake of small molecules into the brains of mice following parabiosis. Our characterization provides an important resource to those attempting to understand the complex interplay between the immune system and the brain as well as other organ systems.
Why the dipolar response in dielectrics and spin-glasses is unavoidably universal
Authors: Cuervo-Reyes Eduardo
Published: July 2016

Materials response to electric or magnetic fields is often dominated by the dynamics of dipoles in the system. This is for instance the case of polar dielectrics and many transition metal compounds. An essential and not yet well understood fact is that, despite their structural diversity, dielectric solids exhibit a striking universality of frequency and time responses, sharing many aspects with the behaviour of spin-glasses. In this article I propose a stochastic approach to dipole dynamics within which the “universal frequency response” derives naturally with Debye’s relaxation mechanism as a special case. This formulation reveals constraints to the form of the relaxation functions, which are essential for a consistent representation of the dynamical slowing-down at the spin-glass transition. Relaxation functions with algebraic- and exponential-tails, as well as damped oscillations, are shown to have a unified representation in which the stable limit of the distribution of waiting-times between dipole flips determines the present type of dynamics.
TRPV1-mediated presynaptic transmission in basolateral amygdala contributes to visceral hypersensitivity in adult rats with neonatal maternal deprivation
Authors: Xiao Ying , Chen Xiaoqi , Zhang Ping-An , Xu Qiya , Zheng Hang , Xu Guang-Yin
Published: July 2016

The central mechanisms of visceral hypersensitivity remain largely unknown. It’s reported that there are highest densities of TRPV1 labeled neurons within basolateral amygdala (BLA). The aim of this study was to explore the role and mechanisms of TRPV1 in BLA in development of visceral hypersensitivity. Visceral hypersensitivity was induced by neonatal maternal deprivation (NMD) and was quantified by abdominal withdrawal reflex. Expression of TRPV1 was determined by Western blot. The synaptic transmission of neurons in BLA was recorded by patch clamping. It was found that the expression of TRPV1 in BLA was significantly upregulated in NMD rats; glutamatergic synaptic activities in BLA were increased in NMD rats; application of capsazepine (TRPV1 antagonist) decreased glutamatergic synaptic activities of BLA neurons in NMD slices through a presynaptic mechanism; application of capsaicin (TRPV1 agonist) increased glutamatergic synaptic activities of BLA neurons in control slices through presynaptic mechanism without affecting GABAergic synaptic activities; microinjecting capsazepine into BLA significantly increased colonic distension threshold both in control and NMD rats. Our data suggested that upregulation of TRPV1 in BLA contributes to visceral hypersensitivity of NMD rats through enhancing excitation of BLA, thus identifying a potential target for treatment of chronic visceral pain.
Volumetric Light-Field Excitation
Authors: Schedl David C. , Bimber Oliver
Published: July 2016

We explain how to concentrate light simultaneously at multiple selected volumetric positions by means of a 4D illumination light field. First, to select target objects, a 4D imaging light field is captured. A light field mask is then computed automatically for this selection to avoid illumination of the remaining areas. With one-photon illumination, simultaneous generation of complex volumetric light patterns becomes possible. As a full light-field can be captured and projected simultaneously at the desired exposure and excitation times, short readout and lighting durations are supported.
Comparison of three different conjugation strategies in the construction of herceptin-bearing paclitaxel-loaded nanoparticles
Authors: Yu Kongtong , Zhou Yulin , Li Yuhuan , Sun Xiangshi , Sun Fengying , Wang Xinmei , Mu Hongyan , Li Jie , Liu Xiaoyue , Teng Lesheng , Li Youxin
Published: July 2016

We developed an improved pre-conjugation strategy, in which herceptin as a ligand was pre-conjugated with DSPE-PEG2000-Mal via chemical cross-linking, followed by conjugation onto the surface of pre-prepared paclitaxel-loaded PLGA/DODMA nanoparticles through hydrophobic interaction and electrostatic attraction for paclitaxel delivery.
Centric and acentric networks using low-symmetry heterotopic carboxylate/pyridyl ligands
Authors: Hall Gregory S. , Angeles Melissa J. , Hicks Jamie , Turner David R.
Published: July 2016

Four isomeric pyridyl/carboxylate ligands demonstrate the appliability of low-symmetry ligands to the formation of chiral materials.
Alkali metal ion induced cube shaped mesoporous hematite particles for improved magnetic properties and efficient degradation of water pollutants
Authors: Roy Mouni , Naskar Milan Kanti
Published: July 2016

Alkali metal ion induced cube shaped mesoporous α-Fe2O3particles showed improved magnetic properties and efficient photo-Fenton degradation of methylene blue.
Homogeneity and elemental distribution in self-assembled bimetallic Pd–Pt aerogels prepared by a spontaneous one-step gelation process
Authors: Oezaslan M. , Liu W. , Nachtegaal M. , Frenkel A. I. , Rutkowski B. , Werheid M. , Herrmann A.-K. , Laugier-Bonnaud C. , Yilmaz H.-C. , Gaponik N. , Czyrska-Filemonowicz A. , Eychmüller A. , Schmidt T. J.
Published: July 2016

Pd–Pt aerogels prepared by a one-step gelation process exhibit alloy features with different elemental distributions over a broad length scale.
Correction: Sparse sampling methods in multidimensional NMR
Authors: Mobli Mehdi , Maciejewski Mark W. , Schuyler Adam D. , Stern Alan S. , Hoch Jeffrey C.
Published: July 2016

Correction for ‘Sparse sampling methods in multidimensional NMR’ by Mehdi Mobli et al., Phys. Chem. Chem. Phys., 2012, 14, 10835–10843.
Activity and SO2 resistance of amorphous CeaTiOx catalysts for the selective catalytic reduction of NO with NH3: in situ DRIFT studies
Authors: Zhang Zhiping , Chen Liqiang , Li Zhibin , Li Pengying , Yuan Fulong , Niu Xiaoyu , Zhu Yujun
Published: July 2016

Amorphous Ce0.3TiOx exhibits a high activity and sulfur resistance for NH3-SCR of NO due to the strong interactions between Ce and Ti.
Magnetic and thermoelectric properties of the ternary pseudo-hollandite BaxCr5Se8(0.5 < x < 0.55) solid solution
Authors: Lefèvre Robin , Berthebaud David , Bux Sabah , Hébert Sylvie , Gascoin Franck
Published: July 2016

The modification of the Ba content within the pseudo hollandite BaxCr5Se8leads to remarkable variations of the transport properties.
The intrinsic rate constants in diffusion-influenced reactions
Authors: Vijaykumar Adithya , Bolhuis Peter G. , ten Wolde Pieter Rein
Published: July 2016

Intrinsic rate constants play a dominant role in the theory of diffusion-influenced reactions, but usually as abstract quantities that are implicitly assumed to be known. However, recently it has become clear that modeling complex processes requires explicit knowledge of these intrinsic rates. In this paper we provide microscopic expressions for the intrinsic rate constants for association and dissociation processes of isotropically interacting particles and illustrate how these rates can be computed efficiently using rare event simulations techniques. In addition, we address the role of the orientational dynamics, for particles interacting via anisotropic potentials.
Comparison of analytical techniques for the identification of bioactive compounds from natural products
Authors: Cieśla Łukasz , Moaddel Ruin
Published: July 2016

Natural product extracts are a rich source of bioactive compounds.
A real time colorimetric ‘two in one’ kit for tracking ppb levels of uric acid and Hg2+ in live HeLa S3 cells and Hg2+ induced keto–enol tautomerism
Authors: Kumari Chanda , Sain Dibyendu , Kumar Ashish , Debnath Sushanta , Saha Partha , Dey Swapan
Published: July 2016

A TBET based ‘turn-on’ fluorescent reagent with high Stokes shifts, exhibits selective and colorimetric detection of biologically important uric acid as well as toxic Hg2+.
Harnessing the pyrroloquinoxaline scaffold for FAAH and MAGL interaction: definition of the structural determinants for enzyme inhibition
Authors: Brindisi Margherita , Brogi Simone , Maramai Samuele , Grillo Alessandro , Borrelli Giuseppe , Butini Stefania , Novellino Ettore , Allarà Marco , Ligresti Alessia , Campiani Giuseppe , Di Marzo Vincenzo , Gemma Sandra
Published: July 2016

The pharmacogenic pyrroloquinoxaline scaffold has been exploited for developing piperazine and 4-aminopiperidine carboxamides/carbamates as inhibitors of the endocannabinoids’ catabolic enzymes fatty acid amide hydrolase and monoacylglycerol lipase.
α-Iminonitrile: a new cyanating agent for the palladium catalyzed C–H cyanation of arenes
Authors: Chen Zhen-Bang , Zhang Fang-Ling , Yuan Qing , Chen Hai-Fang , Zhu Yong-Ming , Shen Jing-Kang
Published: July 2016

An efficient palladium-catalyzed C–H cyanation reaction of arenes using α-iminonitrile as a new cyanating reagent has been developed.
Prevalence and Predictors of Persistent Speech Sound Disorder at Eight Years Old: Findings From a Population Cohort Study
Authors: Wren Yvonne , Miller Laura L. , Peters Tim J. , Emond Alan , Roulstone Sue
Published: July 2016

Purpose

The purpose of this study was to determine prevalence and predictors of persistent speech sound disorder (SSD) in children aged 8 years after disregarding children presenting solely with common clinical distortions (i.e., residual errors).

Method

Data from the Avon Longitudinal Study of Parents and Children (Boyd et al., 2012) were used. Children were classified as having persistent SSD on the basis of percentage of consonants correct measures from connected speech samples. Multivariable logistic regression analyses were performed to identify predictors.

Results

The estimated prevalence of persistent SSD was 3.6%. Children with persistent SSD were more likely to be boys and from families who were not homeowners. Early childhood predictors identified as important were weak sucking at 4 weeks, not often combining words at 24 months, limited use of word morphology at 38 months, and being unintelligible to strangers at age 38 months. School-age predictors identified as important were maternal report of difficulty pronouncing certain sounds and hearing impairment at age 7 years, tympanostomy tube insertion at any age up to 8 years, and a history of suspected coordination problems. The contribution of these findings to our understanding of risk factors for persistent SSD and the nature of the condition is considered.

Conclusion

Variables identified as predictive of persistent SSD suggest that factors across motor, cognitive, and linguistic processes may place a child at risk.

Supplemental Material

https://doi.org/10.23641/asha.14963811
Cochlear Implants 2016: Advances in Candidacy, Technology, and Outcomes, Factors That Drive the Expansion of Pediatric Cochlear Implant Candidacy
Authors: Zwolan Teresa A. , Sorkin Donna L.
Published: July 2016

Cochlear implant candidacy and outcomes have advanced reflecting technology improvements, early identification, and better linkage between the surgical intervention and follow-up care. Children and adults with a range of hearing losses and other issues are now benefitting importantly from traditional cochlear implants as well as hybrid and auditory brainstem implants.
Cochlear Implant Recipients: Device Selection Preferences and Experiences
Authors: Pitt Cache , Heitzinger Christina , Nelson Lauri , Preston Elizabeth , Muñoz Karen
Published: July 2016

Cochlear implants can provide benefit for many deaf and hard of hearing individuals. When candidacy for implantation is determined, recipients are often responsible for selecting the manufacturer of their own cochlear implant. Recipients may, however, encounter various challenges in the selection process, due to the complexity of information and lack of standardization for patient education. This study explored the experiences of cochlear implant recipients with the selection process, including influential factors in their selection, their commitment to the implant, and their post-implantation perceptions. Eighty recipients who had received their implant within the last 12 months completed an online survey. Results of the survey revealed that a wide range of factors influenced selection, that most recipients chose a device without direct recommendations from their audiologist, and that many would have preferred to receive advice from their cochlear implant center in the selection of the device manufacturer.
Coupled‐line directional coupler with tunable power division ratio and operating frequency
Authors: Shen Xiaochuan , Liu Yuanan , Zhou Siyue , Wu Yongle
Published: July 2016

This study presents a novel planar coupled‐line directional coupler with tunable both power division ratio and operating frequency, which is achieved using microstrip technology for the first time. Its tunability of the operating frequency and the power division ratio, or coupling ratio, can be independently controlled by the bias voltages. Moreover, it can simultaneously maintain perfect port match and isolation. On the basis of the even–odd mode analysis method, both the closed‐form analytical equations and parameter discussions are provided to facilitate the practical design. An experimental prototype of the tunable coupler is simulated, fabricated, and measured to demonstrate how it works. The measured results indicate that power division ratio can vary from 0.35 (9 dB) to 0.71 (3 dB) when operating frequency ranges from 0.55 to 1.48 GHz (91.63%) while power division ratio varies from 0.35 (9 dB) to 1 (0 dB) when operating frequency is fixed at 1 GHz, which validated the reliability of the proposed model.
Bifurcations of families of 1D-tori in 4D symplectic maps
Authors: Onken Franziska , Lange Steffen , Ketzmerick Roland , Bäcker Arnd
Published: July 2016

The regular structures of a generic 4d symplectic map with a mixed phase space are organized by one-parameter families of elliptic 1d-tori. Such families show prominent bends, gaps, and new branches. We explain these features in terms of bifurcations of the families when crossing a resonance. For these bifurcations, no external parameter has to be varied. Instead, the longitudinal frequency, which varies along the family, plays the role of the bifurcation parameter. As an example, we study two coupled standard maps by visualizing the elliptic and hyperbolic 1d-tori in a 3d phase-space slice, local 2d projections, and frequency space. The observed bifurcations are consistent with the analytical predictions previously obtained for quasi-periodically forced oscillators. Moreover, the new families emerging from such a bifurcation form the skeleton of the corresponding resonance channel.
Hybrid RANS/LES of turbulent flow in a rotating rib-roughened channel
Authors: Xun Qian-Qiu , Wang Bing-Chen
Published: July 2016

In this paper, we investigate the effect of the Coriolis force on the flow field in a rib-roughened channel subjected to either clockwise or counter-clockwise system rotation using hybrid RANS/LES based on wall modelling. A simplified dynamic forcing scheme incorporating backscatter is proposed for the hybrid simulation approach. The flow is characterized by a Reynolds number of Re = 1.5 × 104 and a rotation number Ro ranging from −0.6 to 0.6. The mean flow speed and turbulence level near the roughened wall are enhanced under counter-clockwise rotation and suppressed under clockwise rotation. The Coriolis force significantly influences the stability of the wall shear layer and the free shear layers generated by the ribs. Consequently, it is interesting to observe that the classification of the roughness type relies not only on the pitch ratio, but also on the rotation number in the context of rotating rib-roughened flows. In order to validate the present hybrid approach, the first- and second-order statistical moments of the velocity field obtained from the simulations are thoroughly compared with the available laboratory measurement data.
The melting of stable glasses is governed by nucleation-and-growth dynamics
Authors: Jack Robert L. , Berthier Ludovic
Published: July 2016

We discuss the microscopic mechanisms by which low-temperature amorphous states, such as ultrastable glasses, transform into equilibrium fluids, after a sudden temperature increase. Experiments suggest that this process is similar to the melting of crystals, thus differing from the behaviour found in ordinary glasses. We rationalize these observations using the physical idea that the transformation process takes place close to a “hidden” equilibrium first-order phase transition, which is observed in systems of coupled replicas. We illustrate our views using simulation results for a simple two-dimensional plaquette spin model, which is known to exhibit a range of glassy behaviour. Our results suggest that nucleation-and-growth dynamics, as found near ordinary first-order transitions, is also the correct theoretical framework to analyse the melting of ultrastable glasses. Our approach provides a unified understanding of multiple experimental observations, such as propagating melting fronts, large kinetic stability ratios, and “giant” dynamic length scales. We also provide a comprehensive discussion of available theoretical pictures proposed in the context of ultrastable glass melting.
Parametric symmetries in exactly solvable real and PT symmetric complex potentials
Authors: Yadav Rajesh Kumar , Khare Avinash , Bagchi Bijan , Kumari Nisha , Mandal Bhabani Prasad
Published: July 2016

In this paper, we discuss the parametric symmetries in different exactly solvable systems characterized by real or complex PT symmetric potentials. We focus our attention on the conventional potentials such as the generalized Pöschl Teller (GPT), Scarf-I, and PT symmetric Scarf-II which are invariant under certain parametric transformations. The resulting set of potentials is shown to yield a completely different behavior of the bound state solutions. Further, the supersymmetric partner potentials acquire different forms under such parametric transformations leading to new sets of exactly solvable real and PT symmetric complex potentials. These potentials are also observed to be shape invariant (SI) in nature. We subsequently take up a study of the newly discovered rationally extended SI potentials, corresponding to the above mentioned conventional potentials, whose bound state solutions are associated with the exceptional orthogonal polynomials (EOPs). We discuss the transformations of the corresponding Casimir operator employing the properties of the so(2, 1) algebra.
Phenomenology of a flow around a circular cylinder at sub-critical and critical Reynolds numbers
Authors: Capone Alessandro , Klein Christian , Di Felice Fabio , Miozzi Massimo
Published: July 2016

In this work, the flow around a circular cylinder is investigated at Reynolds numbers ranging from 79 000 up to 238 000 by means of a combined acquisition system based on Temperature Sensitive Paint (TSP) and particle velocimetry. The proposed setup allows simultaneous and time-resolved measurement of absolute temperature and relative skin friction fields onto the cylinder surface and near-wake velocity field. Combination of time-resolved surface measurements and planar near-field velocity data allows the investigation of the profound modifications undergone by the wall shear stress topology and its connections to the near-field structure as the flow regime travels from the sub-critical to the critical regime. Laminar boundary-layer separation, transition, and re-attachment are analyzed in the light of temperature, relative skin friction maps, and Reynolds stress fields bringing about a new perspective on the relationship between boundary layer development and shear layer evolution. The fast-responding TSP employed allows high acquisition frequency and calculation of power spectral density from surface data. Correlation maps of surface and near-wake data provide insight into the relationship between boundary-layer evolution and vortex shedding. We find that as the Reynolds number approaches the critical state, the separation line oscillations feature an increasingly weaker spectrum peak compared to the near-wake velocity spectrum. In the critical regime, separation line oscillations are strongly reduced and the correlation to the local vorticity undergoes an overall decrease giving evidence of modifications in the vortex shedding mechanism.
Interparticle interactions mediated superspin glass to superferromagnetic transition in Ni-bacterial cellulose aerogel nanocomposites
Authors: Thiruvengadam V. , Vitta Satish
Published: July 2016

The interparticle interactions in the magnetic nanocomposites play a dominant role in controlling phase transitions: superparamagnetic to superspin glass and to superferromagnetic. These interactions can be tuned by controlling the size and number density of nanoparticles. The aerogel composites, 0.3Ni-BC and 0.7Ni-BC, consisting of Ni nanoparticles distributed in the bacterial cellulose have been used as a model system to study these interactions. Contrary to conventional approach, size of Ni-nanoparticles is not controlled and allowed to form naturally in bacterial cellulose template. The uncontrolled growth of Ni results in the formation of nanoparticles with 3 different size distributions—<10 nm particles along the length of fibrils, 50 nm particles in the intermediate spaces between the fibrils, and >100 nm particles in voids formed by reticulate structure. At room temperature, the composites exhibit a weakly ferromagnetic behaviour with a coercivity of 40 Oe, which increases to 160 Oe at 10 K. The transition from weakly ferromagnetic state to superferromagnetic state at low temperatures is mediated by the superspin glass state at intermediate temperatures via the interparticle interactions aided by nanoparticles present along the length of fibres. A temperature dependent microstructural model has been developed to understand the magnetic behaviour of nanocomposite aerogels.
Singlet-paired coupled cluster theory for open shells
Authors: Gomez John A. , Henderson Thomas M. , Scuseria Gustavo E.
Published: July 2016

Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior for strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.
Ab initio study of vacancy formation in cubic LaMnO3 and SmCoO3 as cathode materials in solid oxide fuel cells
Authors: Olsson Emilia , Aparicio-Anglès Xavier , de Leeuw Nora H.
Published: July 2016

Doped LaMnO3 and SmCoO3 are important solid oxide fuel cell cathode materials. The main difference between these two perovskites is that SmCoO3 has proven to be a more efficient cathode material than LaMnO3 at lower temperatures. In order to explain the difference in efficiency, we need to gain insight into the materials’ properties at the atomic level. However, while LaMnO3 has been widely studied, ab initio studies on SmCoO3 are rare. Hence, in this paper, we perform a comparative DFT + U study of the structural, electronic, and magnetic properties of these two perovskites. To that end, we first determined a suitable Hubbard parameter for the Co d–electrons to obtain a proper description of SmCoO3 that fully agrees with the available experimental data. We next evaluated the impact of oxygen and cation vacancies on the geometry, electronic, and magnetic properties. Oxygen vacancies strongly alter the electronic and magnetic structures of SmCoO3, but barely affect LaMnO3. However, due to their high formation energy, their concentrations in the material are very low and need to be induced by doping. Studying the cation vacancy concentration showed that the formation of cation vacancies is less energetically favorable than oxygen vacancies and would thus not markedly influence the performance of the cathode.
CsPbBr3 nanocrystal saturable absorber for mode-locking ytterbium fiber laser
Authors: Zhou Yan , Hu Zhiping , Li Yue , Xu Jianqiu , Tang Xiaosheng , Tang Yulong
Published: July 2016

Cesium lead halide perovskite nanocrystals (CsPbX3, X = Cl, Br, I) have been reported as efficient light-harvesting and light-emitting semiconductor materials, but their nonlinear optical properties have been seldom touched upon. In this paper, we prepare layered CsPbBr3 nanocrystal films and characterize their physical properties. Broadband linear absorption from ∼0.8 to over 2.2 μm and nonlinear optical absorption at the 1-μm wavelength region are measured. The CsPbBr3 saturable absorber (SA), manufactured by drop-casting of colloidal CsPbBr3 liquid solution on a gold mirror, shows modulation depth and saturation intensity of 13.1% and 10.7 MW/cm2, respectively. With this SA, mode-locking operation of a polarization-maintained ytterbium fiber laser produces single pulses with duration of ∼216 ps, maximum average output power of 10.5 mW, and the laser spectrum is centered at ∼1076 nm. This work shows that CsPbBr3 films can be efficient SA candidates for fiber lasers and also have great potential to become broadband linear and nonlinear optical materials for photonics and optoelectronics.
Financial risks of solar photovoltaic companies: Do managerial power and ownership concentration really matter? Empirical evidence from China
Authors: Liu Yue , Shuai Chuanmin , Ding Liping
Published: July 2016

Photovoltaic companies have been developing very rapidly in China and facing huge financial crisis as well. By adopting the Z-score and multi-regression models, this paper evaluated the financial risks of China's 57 solar photovoltaic companies, in an attempt to reveal the relationships between managerial power, ownership concentration, and their financial risks. Empirical results show that the expansion of photovoltaic companies' managerial power significantly increases the financial risks of these companies. More specifically, (1) combining board chairman and the Chief Executive Officer (CEO) increases their financial risks; (2) the size of the board of directors and the tenure of the CEO have positive correlations with their financial risks; and (3) the percentage of management shareholdings and the degree of ownership concentration have negative correlations with their financial risks. Management implications are proposed accordingly based on the findings of this study.
Multi-step resistive switching behavior of Li-doped ZnO resistance random access memory device controlled by compliance current
Authors: Lin Chun-Cheng , Tang Jian-Fu , Su Hsiu-Hsien , Hong Cheng-Shong , Huang Chih-Yu , Chu Sheng-Yuan
Published: July 2016

The multi-step resistive switching (RS) behavior of a unipolar Pt/Li0.06Zn0.94O/Pt resistive random access memory (RRAM) device is investigated. It is found that the RRAM device exhibits normal, 2-, 3-, and 4-step RESET behaviors under different compliance currents. The transport mechanism within the device is investigated by means of current-voltage curves, in-situ transmission electron microscopy, and electrochemical impedance spectroscopy. It is shown that the ion transport mechanism is dominated by Ohmic behavior under low electric fields and the Poole-Frenkel emission effect (normal RS behavior) or Li+ ion diffusion (2-, 3-, and 4-step RESET behaviors) under high electric fields.
Temporal and spatial evolution of runaway electrons at the instability moments in Damavand tokamak
Authors: Pourshahab B. , Abdi M. R. , Sadighzadeh A. , Rasouli C.
Published: July 2016

The time and position behavior of runaway electrons at the Parail–Pogutse instability moments has been investigated using experimental observations in plasma current, loop voltage, the Hard X-ray (HXR) radiations, and 18 poloidal pickup coils signals received by data acquisition system simultaneously. The conditional average sampling (CAS) method was used to analyze the output data. Moreover, a filament current code was modified to study the runaway electrons beam movement in the event of instabilities. The results display a rapid drift of runaway beam toward the inner wall of the vacuum vessel and the collision with the wall components at the instability moments. The existence of the collisions in these experiments is evident in the HXR bursts which are considered as the main trigger for CAS Analysis. Also, the variation of HXR bursts with the toroidal magnetic field shows that the hard X-ray bursts drop with increase in the toroidal magnetic field and runaway electrons confinement quality.
Field emission analysis of band bending in donor/acceptor heterojunction
Authors: Xing Yingjie , Li Shuai , Wang Guiwei , Zhao Tianjiao , Zhang Gengmin
Published: July 2016

The donor/acceptor heterojunction plays an important role in organic solar cells. An investigation of band bending in the donor/acceptor heterojunction is helpful in analysis of the charge transport behavior and for the improvement of the device performance. In this work, we report an approach for detection of band bending in a donor/acceptor heterojunction that has been prepared on a small and sharp tungsten tip. In situ field emission measurements are performed after the deposition process, and a linear Fowler-Nordheim plot is obtained from the fresh organic film surface. The thickness-dependent work function is then measured in the layer-by-layer deposited heterojunction. Several different types of heterojunction (zinc phthalocyanine (ZnPc)/C60, copper phthalocyanine (CuPc)/3,4,9,10-perylenetetracarboxylic bisbenzimidazole, and CuPc/C60) are fabricated and analyzed. The different charge transfer directions in the heterojunctions are distinguished by field emission measurements. The calculation method used to determine the band bending is then discussed in detail. A triple layer heterojunction (C60/ZnPc/CuPc) is also analyzed using this method. A small amount of band bending is measured in the outer CuPc layer. This method provides an independent reference method for determination of the band bending in an organic heterojunction that will complement photoemission spectroscopy and current-voltage measurement methods.
National labs are nurturing clean-energy startups
Authors: Kramer David
Published: July 2016

Programs aim to assist scientists in fleshing out their inventions.
Studies on the Nitrogen Metabolism of Plants VIII. Utilization of a-Oximinocarboxylic Acids by Oat Plants
Authors: Wood JG , R Hone Mary
Published: July 2016

Oat plants were grown in culture solutions containing hydroxylamine, oximinopropionic acid, trans-oximinosuccinic acid and cis- and trans-oximinoglutaric acids in different concentrations at pH 7. MorpholOgical changes and nitrogen contents, including protein-N contents, of these plants are described. It is shown that all these oximes can be utilized as a source of nitrogen for protein synthesis; optimum concentrations for protein synthesis in oats is about 1 x 1O-5M for hydroxylamine, 1 x 1O-4M for oximinopropionate and 1 x 1O-3M for the oximino-dicarboxylic acids.
A Study of Certain Aspects of the Ecology of the Inter-Tidal Zone of the New South Wales Coast
Authors: Dakin WJ , Benneti IsobeI , Pope Elizabeth
Published: July 2016

This paper is the result of an ecological study pursued for several years and extending over the entire length of the New South Wales coast. It is not a systematic investigation of one limited locality, but an attempt to analyse basically a long stretch of the east Australian coast.
The Wood Anatomy of the Proteaceae
Authors: Margabet Chattaway M
Published: July 2016

This paper contains a general description of the wood anatomy of 26 genera of the Proteaceae. The genera described are those which produce timber trees or large woody shrubs. A map is given to show the geographical distribution of the woody genera of the Proteaceae. The relationship of the wood anatomy to the botanical classification is discussed, with special reference to those genera in which there are marked anatomical differences within the genus.
Yield Trends in The Wheat Belt of South Australia During 1896-1941
Authors: Cornish EA
Published: July 2016

The history of the wheat industry in South Australia is reviewed to provide a background for discussion of the fomls of trend observed in yield. The period chosen for examination was 1896-1941, and the analysis extends to practically the entire wheat belt, the basic territorial unit used for assessing yield being the hundred, the mean area of which in South Australia is approximately 118 square miles. As a preliminary to the evaluation of the trends it was necessary to estimate and to eliminate the effects of variations in seasonal rainfall; the statistical technique used was that of partial regression, and reasons are given for the choice of rainfall variates.