bluuebunny/crossref_metadata_2025 huggingface dataset:
DDX3 DEAD-box RNA helicase plays a central role in mitochondrial protein quality control in Leishmania
Authors: Padmanabhan Prasad Kottayil , Zghidi-Abouzid Ouafa , Samant Mukesh , Dumas Carole , Aguiar Bruno Guedes , Estaquier Jerome , Papadopoulou Barbara
Published: October 2016

DDX3 is a highly conserved member of ATP-dependent DEAD-box RNA helicases with multiple functions in RNA metabolism and cellular signaling. Here, we describe a novel function for DDX3 in regulating the mitochondrial stress response in the parasitic protozoan Leishmania. We show that genetic inactivation of DDX3 leads to the accumulation of mitochondrial reactive oxygen species (ROS) associated with a defect in hydrogen peroxide detoxification. Upon stress, ROS production is greatly enhanced, causing mitochondrial membrane potential loss, mitochondrial fragmentation, and cell death. Importantly, this phenotype is exacerbated upon oxidative stress in parasites forced to use the mitochondrial oxidative respiratory machinery. Furthermore, we show that in the absence of DDX3, levels of major components of the unfolded protein response as well as of polyubiquitinated proteins increase in the parasite, particularly in the mitochondrion, as an indicator of mitochondrial protein damage. Consistent with these findings, immunoprecipitation and mass-spectrometry studies revealed potential interactions of DDX3 with key components of the cellular stress response, particularly the antioxidant response, the unfolded protein response, and the AAA-ATPase p97/VCP/Cdc48, which is essential in mitochondrial protein quality control by driving proteosomal degradation of polyubiquitinated proteins. Complementation studies using DDX3 deletion mutants lacking conserved motifs within the helicase core support that binding of DDX3 to ATP is essential for DDX3’s function in mitochondrial proteostasis. As a result of the inability of DDX3-depleted Leishmania to recover from ROS damage and to survive various stresses in the host macrophage, parasite intracellular development was impaired. Collectively, these observations support a central role for the Leishmania DDX3 homolog in preventing ROS-mediated damage and in maintaining mitochondrial protein quality control.
Simple phosphinate ligands access zinc clusters identified in the synthesis of zinc oxide nanoparticles
Authors: Pike Sebastian D. , White Edward R. , Shaffer Milo S. P. , Williams Charlotte K.
Published: October 2016

The bottom-up synthesis of ligand-stabilized functional nanoparticles from molecular precursors is widely applied but is difficult to study mechanistically. Here we use31P NMR spectroscopy to follow the trajectory of phosphinate ligands during the synthesis of a range of ligated zinc oxo clusters, containing 4, 6 and 11 zinc atoms. Using an organometallic route, the clusters interconvert rapidly and self-assemble in solution based on thermodynamic equilibria rather than nucleation kinetics. These clusters are also identifiedin situduring the synthesis of phosphinate-capped zinc oxide nanoparticles. Unexpectedly, the ligand is sequestered to a stable Zn11cluster during the majority of the synthesis and only becomes coordinated to the nanoparticle surface, in the final step. In addition to a versatile and accessible route to (optionally doped) zinc clusters, the findings provide an understanding of the role of well-defined molecular precursors during the synthesis of small (2–4 nm) nanoparticles.
Genomic evidence for plant-parasitic nematodes as the earliest Wolbachia hosts
Authors: Brown Amanda M. V. , Wasala Sulochana K. , Howe Dana K. , Peetz Amy B. , Zasada Inga A. , Denver Dee R.
Published: October 2016

Wolbachia, one of the most widespread endosymbionts, is a target for biological control of mosquito-borne diseases (malaria and dengue virus), and antibiotic elimination of infectious filarial nematodes. We sequenced and analyzed the genome of a new Wolbachia strain (wPpe) in the plant-parasitic nematode Pratylenchus penetrans. Phylogenomic analyses placed wPpe as the earliest diverging Wolbachia, suggesting two evolutionary invasions into nematodes. The next branches comprised strains in sap-feeding insects, suggesting Wolbachia may have first evolved as a nutritional mutualist. Genome size, protein content, %GC, and repetitive DNA allied wPpe with mutualistic Wolbachia, whereas gene repertoire analyses placed it between parasite (A, B) and mutualist (C, D, F) groups. Conservation of iron metabolism genes across Wolbachia suggests iron homeostasis as a potential factor in its success. This study enhances our understanding of this globally pandemic endosymbiont, highlighting genetic patterns associated with host changes. Combined with future work on this strain, these genomic data could help provide potential new targets for plant-parasitic nematode control.
Quadrupole lattice resonances in plasmonic crystal excited by cylindrical vector beams
Authors: Sakai Kyosuke , Nomura Kensuke , Yamamoto Takeaki , Omura Tatsuya , Sasaki Keiji
Published: October 2016

We report a scheme to exploit low radiative loss plasmonic resonance by combining a dark (subradiant) mode and a lattice resonance. We theoretically demonstrate that such dark-mode lattice resonances in periodic arrays of nanodisks or plasmonic crystals can be excited by vertically incident light beams. We investigate the excitation of lattice resonances in a finite sized, square-lattice plasmonic crystal by two types of cylindrical vector beams and a linearly polarized Gaussian beam. Quadrupole lattice resonances are excited by all three beams, and the largest peak intensity is obtained by using a specific type of cylindrical vector beam. Because of their lower radiative losses with many hotspots, the quadrupole lattice resonances in plasmonic crystal may pave the way for photonic research and applications that require strong light-matter interactions.
Quantum key distribution with prepare-and-measure Bell test
Authors: Tan Yong-gang
Published: October 2016

The prepare-and-measure quantum key distribution (QKD) has the merits of fast speed, high key generation rate, and easy implementation. However, the detector side channel attacks greatly undermine the security of the key bits. The eavesdropper, Eve, exploits the flaws of the detectors to obtain illegal information without violating quantum principles. It means that she can intervene in the communication without being detected. A prepare-and-measure Bell test protocol will be proposed. By randomly carrying out Bell test at the side of the information receiver, Bob, Eve’s illegal information gain within the detector side channel attack can be well bounded. This protocol does not require any improvement on the detectors used in available prepare-and-measure QKD. Though we only illustrate its application in the BB84 protocol, it is applicable for any prepare-and-measure QKD.
Graphlet-based Characterization of Directed Networks
Authors: Sarajlić Anida , Malod-Dognin Noël , Yaveroğlu Ömer Nebil , Pržulj Nataša
Published: October 2016

We are flooded with large-scale, dynamic, directed, networked data. Analyses requiring exact comparisons between networks are computationally intractable, so new methodologies are sought. To analyse directed networks, we extend graphlets (small induced sub-graphs) and their degrees to directed data. Using these directed graphlets, we generalise state-of-the-art network distance measures (RGF, GDDA and GCD) to directed networks and show their superiority for comparing directed networks. Also, we extend the canonical correlation analysis framework that enables uncovering the relationships between the wiring patterns around nodes in a directed network and their expert annotations. On directed World Trade Networks (WTNs), our methodology allows uncovering the core-broker-periphery structure of the WTN, predicting the economic attributes of a country, such as its gross domestic product, from its wiring patterns in the WTN for up-to ten years in the future. It does so by enabling us to track the dynamics of a country’s positioning in the WTN over years. On directed metabolic networks, our framework yields insights into preservation of enzyme function from the network wiring patterns rather than from sequence data. Overall, our methodology enables advanced analyses of directed networked data from any area of science, allowing domain-specific interpretation of a directed network’s topology.
Bone marrow-derived and peritoneal macrophages have different inflammatory response to oxLDL and M1/M2 marker expression – implications for atherosclerosis research
Authors: Bisgaard Line S. , Mogensen Christina K. , Rosendahl Alexander , Cucak Helena , Nielsen Lars Bo , Rasmussen Salka E. , Pedersen Tanja X.
Published: October 2016

Macrophages are heterogeneous and can polarize into specific subsets, e.g. pro-inflammatory M1-like and re-modelling M2-like macrophages. To determine if peritoneal macrophages (PEMs) or bone marrow derived macrophages (BMDMs) resembled aortic macrophages from ApoE−/− mice, their M1/M2 phenotype, inflammatory status, and lipid metabolism signatures were compared. oxLDL accumulation was similar in PEMs and BMDMs. On protein expression level, BMDMs showed an M2-like CD206highCD11clow profile, while cholesterol loading led to enhanced CD11c expression and reduced MCP-1 secretion. In contrast, PEMs expressed low levels of CD206 and CD11c, and responded to cholesterol loading by increasing CD11c expression and MCP-1 secretion. mRNA expression of M1/M2 markers was higher in PEMS than BMDMs, while lipid metabolism genes were similarly expressed. Whole aorta flow cytometry showed an accumulation of M2-like CD206highCD11clow macrophages in advanced versus early atherosclerotic disease in ApoE−/− mice. In isolated lesions, mRNA levels of the M2 markers Socs2, CD206, Retnla, and IL4 were downregulated with increasing disease severity. Likewise, mRNA expression of lipid metabolism genes (SREBP2, ACSL1, SRB1, DGAT1, and cpt1a) was decreased in advanced versus early lesions. In conclusion, PEMs and BMDMs are phenotypically distinct and differ from macrophages in lesions with respect to expression of M1/M2 markers and lipid metabolism genes.
The Role of PIK3CA Mutations among Lung Adenocarcinoma Patients with Primary and Acquired Resistance to EGFR Tyrosine Kinase Inhibition
Authors: Wu Shang-Gin , Chang Yih-Leong , Yu Chong-Jen , Yang Pan-Chyr , Shih Jin-Yuan
Published: October 2016

To understand the impact of PIK3CA mutations on clinical characteristics and treatment response to epidermal growth factor tyrosine kinase inhibitors (EGFR TKIs) of lung adenocarcinoma, we examined PIK3CA and EGFR mutations in lung adenocarcinoma patients, and analyzed their clinical outcomes. Surgically excised tumor, bronchoscopy biopsy/brushing specimens and pleural effusions were prospectively collected from 1029 patients. PIK3CA and EGFR mutations were analyzed by RT-PCR and direct sequencing. In EGFR TKI-nave specimens, PIK3CA mutation rate was 1.8% (14/760). Twelve patients had coexisting PIK3CA and EGFR mutations. Among the 344 EGFR TKI-treated EGFR mutant patients, there was no significant difference in treatment response (p = 0.476) and progression-free survival (p = 0.401) of EGFR TKI between PIK3CA mutation-positive and negative patients. The PIK3CA mutation rate in lung adenocarcinoma with acquired resistance to EGFR TKI is not higher than that in EGFR TKI-naïve tissue specimens (2.9% (6/207) vs. 1.8%; p = 0.344). Of the 74 patients with paired specimens (TKI-naïve and acquired resistance to TKIs) only one patient (1.4%) developed acquired PIK3CA (E545K) mutation, and he also had acquired EGFR (T790M) mutation. In conclusion, PIK3CA mutation may not be associated with primary resistance to EGFR TKI among lung adenocarcinoma patients. Acquired PIK3CA mutation related to EGFR TKI treatment is rare.
Metabolomics approach reveals metabolic disorders and potential biomarkers associated with the developmental toxicity of tetrabromobisphenol A and tetrachlorobisphenol A
Authors: Ye Guozhu , Chen Yajie , Wang Hong-ou , Ye Ting , Lin Yi , Huang Qiansheng , Chi Yulang , Dong Sijun
Published: October 2016

Tetrabromobisphenol A and tetrachlorobisphenol A are halogenated bisphenol A (H-BPA), and has raised concerns about their adverse effects on the development of fetuses and infants, however, the molecular mechanisms are unclear, and related metabolomics studies are limited. Accordingly, a metabolomics study based on gas chromatography-mass spectrometry was employed to elucidate the molecular developmental toxicology of H-BPA using the marine medaka (Oryzias melastigmas) embryo model. Here, we revealed decreased synthesis of nucleosides, amino acids and lipids, and disruptions in the TCA (tricarboxylic acid) cycle, glycolysis and lipid metabolism, thus inhibiting the developmental processes of embryos exposed to H-BPA. Unexpectedly, we observed enhanced neural activity accompanied by lactate accumulation and accelerated heart rates due to an increase in dopamine pathway and a decrease in inhibitory neurotransmitters following H-BPA exposure. Notably, disorders of the neural system, and disruptions in glycolysis, the TCA cycle, nucleoside metabolism, lipid metabolism, glutamate and aspartate metabolism induced by H-BPA exposure were heritable. Furthermore, lactate and dopa were identified as potential biomarkers of the developmental toxicity of H-BPA and related genetic effects. This study has demonstrated that the metabolomics approach is a useful tool for obtaining comprehensive and novel insights into the molecular developmental toxicity of environmental pollutants.
A generalized quantitative interpretation of dark-field contrast for highly concentrated microsphere suspensions
Authors: Gkoumas Spyridon , Villanueva-Perez Pablo , Wang Zhentian , Romano Lucia , Abis Matteo , Stampanoni Marco
Published: October 2016

In X-ray grating interferometry, dark-field contrast arises due to partial extinction of the detected interference fringes. This is also called visibility reduction and is attributed to small-angle scattering from unresolved structures in the imaged object. In recent years, analytical quantitative frameworks of dark-field contrast have been developed for highly diluted monodisperse microsphere suspensions with maximum 6% volume fraction. These frameworks assume that scattering particles are separated by large enough distances, which make any interparticle scattering interference negligible. In this paper, we start from the small-angle scattering intensity equation and, by linking Fourier and real-space, we introduce the structure factor and thus extend the analytical and experimental quantitative interpretation of dark-field contrast, for a range of suspensions with volume fractions reaching 40%. The structure factor accounts for interparticle scattering interference. Without introducing any additional fitting parameters, we successfully predict the experimental values measured at the TOMCAT beamline, Swiss Light Source. Finally, we apply this theoretical framework to an experiment probing a range of system correlation lengths by acquiring dark-field images at different energies. This proposed method has the potential to be applied in single-shot-mode using a polychromatic X-ray tube setup and a single-photon-counting energy-resolving detector.
Nanoscale solely amorphous layer in silicon wafers induced by a newly developed diamond wheel
Authors: Zhang Zhenyu , Guo Liangchao , Cui Junfeng , Wang Bo , Kang Renke , Guo Dongming
Published: October 2016

Nanoscale solely amorphous layer is achieved in silicon (Si) wafers, using a developed diamond wheel with ceria, which is confirmed by high resolution transmission electron microscopy (HRTEM). This is different from previous reports of ultraprecision grinding, nanoindentation and nanoscratch, in which an amorphous layer at the top, followed by a crystalline damaged layer beneath. The thicknesses of amorphous layer are 43 and 48 nm at infeed rates of 8 and 15 μm/min, respectively, which is verified using HRTEM. Diamond-cubic Si-I phase is verified in Si wafers using selected area electron diffraction patterns, indicating the absence of high pressure phases. Ceria plays an important role in the diamond wheel for achieving ultrasmooth and bright surfaces using ultraprecision grinding.
Comparison of overall survival in patients with unresectable hepatic metastases with or without transarterial chemoembolization: A Propensity Score Matching Study
Authors: Wang F. Y. , Meng W. , Li Y. , Li T. , Qin C. Y.
Published: October 2016

Transarterial chemoembolization (TACE) has mostly been used in hypervascular tumours such as hepatocellular carcinoma, and may be an effective palliative treatment in patients with metastatic liver cancer. Our goal is to determine whether TACE increases overall survival (OS) of in patients with liver metastases. The retrospective cohort study included 171 patients with liver metastases diagnosed between 2001 and 2015. OS was compared between the TACE and non-TACE groups after propensity score matching to reduce the effects of selection bias and potential confounders. Multivariate analysis was conducted to confirm the confounding factors with OS. After excluding 43 patients, 128 patients were analysed and among thses 64 patients (50%) were included in the TACE group. In the propensity score matched cohort (42 pairs), the OS was non-significantly longer in the TACE group than in the non-TACE group (p = 0.789). Multivariate analysis revealed that international normalized ratio (INR) (HR 0.058, 95%CI: [0.005, 0.681]; p = 0.023) and Radiofrequency ablation (RFA) (HR 3.054, 95%CI: [1.418, 6.579]; p = 0.004) were independent risk factors for OS in patients with unresectable liver metastases. There were no significant differences in patients with unresectable liver metastases with or without TACE. INR and RFA can significantly affect OS in patients with unresectable liver metastases.
Development of Rapid Electrobiochemical Assays for Food Toxins
Authors: Zia A. I. , Mukhopadhyay S. C.
Published: October 2016

Food consumed by human beings may contain biotoxins, endotoxins, or chemotoxins that could lead to adverse effects on human health. Ingested toxins generally produce short-term illness that could be fatal. Biotoxins may occur in human food naturally, whereas endotoxins may arise in the food chain due to bacterial degradation. Chemotoxins are added during food preparation; their leaching from plastic packaging leads to long-term malfunctions of the endocrine system. Phthalates are ubiquitous chemotoxins that have penetrated the ecosystem due to their wide use in the plastics industry. Conventional quantification assays for food toxins require skill, expensive equipment, and longer analysis time than the assay techniques presented here. Hydrogen bonding and electrostatic attraction phenomena can be used for the selective capture of toxins present in consumable food. Analyte-sensitive materials immobilized on interdigital capacitive sensing surfaces were developed to design novel assay techniques for real-time monitoring. This chapter describes the electrobiochemical detection of food toxins employing electrochemical impedance spectroscopy in conjunction with smart sensors and selective coatings to quantify their concentration in real time without the need for sample preparation, bulky instrumentation, or skilled operators.
Correction: Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids
Authors: Corzilius Björn
Published: October 2016

Correction for ‘Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids’ by Björn Corzilius et al., Phys. Chem. Chem. Phys., 2016, DOI: 10.1039/c6cp04621e.
The electron's spin and molecular chirality – how are they related and how do they affect life processes?
Authors: Michaeli Karen , Kantor-Uriel Nirit , Naaman Ron , Waldeck David H.
Published: October 2016

The recently discovered chiral induced spin selectivity (CISS) effect gives rise to a spin selective electron transmission through biomolecules.
Sewage sludge-based functional nanomaterials: development and applications
Authors: Yuan Shi-Jie , Dai Xiao-Hu
Published: October 2016

The development and applications of sewage sludge-based functional nanomaterials are reviewed, and future opportunities and challenges are addressed.
Continuous high throughput nanofluidic separation through tangential-flow vertical nanoslit arrays
Authors: Bassu Margherita , Holik Peter , Schmitz Sam , Steltenkamp Siegfried , Burg Thomas P.
Published: October 2016

We describe the fabrication of ultra uniform nanoslit arrays and their application to continuous separation of small molecules by charge.
Comparative studies on photophysical and optical limiting characterizations of low symmetry phthalocyanine linked to Fe3O4–Ag core–shell or hybrid nanoparticles
Authors: Bankole Owolabi M. , Nyokong Tebello
Published: October 2016

Zinc phthalocyanine was linked to Fe3O4/Ag core–shell or Fe3O4Ag hybrid heterodimer nanoparticles with improved nonlinear optical behavior.
Laccase-catalyzed controlled radical polymerization of N-vinylimidazole
Authors: Fodor Csaba , Gajewska Bernadetta , Rifaie-Graham Omar , Apebende Edward A. , Pollard Jonas , Bruns Nico
Published: October 2016

Laccase fromTrametes versicolorcatalyzes the controlled radical polymerization ofN-vinylimidazole, yielding narrowly dispersed, metal-free polymers.
Electronic and magnetic properties regulation of finite to infinite half sandwich organo-transition-metal-complexes functionalized graphene
Authors: Zhang Xiuyun , Bian Yajie , Sun Weikang , Hu Ting , Liu Yongjun
Published: October 2016

Total band gaps (Δt) and band gaps of free “graphene”, ignoring impurity bands of TMnOLs (Δg).
High-sensitivity stimuli-responsive polysiloxane synthesized via catalyst-free aza-Michael addition for ibuprofen loading and controlled release
Authors: Li Shusheng , Feng Shengyu
Published: October 2016

High-sensitive stimuli-responsive polysiloxanes with high sensitive respond to three changes of thermo-, pH-, and salinity were synthesized via a facile, highly efficient, catalyst-free aza-Michael addition of poly(aminopropylmethylsiloxane) with N-isopropylacrylamide.
High pressure studies of trimethyltin azide by Raman scattering, IR absorption, and synchrotron X-ray diffraction
Authors: Jiang Junru , Zhu Peifen , Li Dongmei , Chen Yanmei , Li Miaoran , Wang Xiaoli , Liu Bingbing , Cui Qiliang , Zhu Hongyang
Published: October 2016

The azide group becomes increasingly asymmetric with increasing pressure, and the amorphization pressure of azide group is much lower than that of inorganic azide.
Preparation and application of surface activated Si-MCM-41 and SBA-16 as reusable supports for reduction of cyclic ketones with preferential stereoselectivity
Authors: Chaudhuri Haribandhu , Dash Subhajit , Sarkar Ashis
Published: October 2016

Surface activated calcined Si-MCM-41 and SBA-16 materials as activators in the reduction of cyclic ketones.
A label-free kissing complex-induced fluorescence sensor for DNA and RNA detection by using DNA-templated silver nanoclusters as a signal transducer
Authors: Zhang Kai , Wang Ke , Zhu Xue , Xie Minhao , Xu Fei
Published: October 2016

A new strategy integrate silver nanoclusters (AgNCs) and riboswitches for the expanding of the application of a kissing complexes-induced sensor (KCIS) for the assay of DNA and RNA was reported.
Improving critical thinking via authenticity: the CASPiE research experience in a military academy chemistry course
Authors: Chase A. M. , Clancy H. A. , Lachance R. P. , Mathison B. M. , Chiu M. M. , Weaver G. C.
Published: October 2016

Course-based undergraduate research experiences (CUREs) can introduce many students to authentic research activities in a cost-effective manner. Past studies have shown that students who participated in CUREs report greater interest in chemistry, better data collection and analysis skills, and enhanced scientific reasoning compared to traditional laboratory activities. Though self-reports are informative, performance measures are needed to evaluate CURE effectiveness objectively. The present study examines whether a CURE implementation at the United States Military Academy (by the Center for Authentic Science Practice in Education [CASPiE]) affects students' self-reported perceptions or critical thinking test scores. Students reported significant increases in their perceptions of learning through the laboratory, authentic scientific laboratory practices and interest in chemistry when compared to previous chemistry courses with traditional laboratory activities. Results also showed a significant increase in critical thinking scores, moderated by student perception of the authenticity of the laboratory activities.
Mechanistic study of the rhodium-catalyzed carboxylation of simple aromatic compounds with carbon dioxide
Authors: Suga Takuya , Saitou Takanobu , Takaya Jun , Iwasawa Nobuharu
Published: October 2016

A detailed mechanistic study of the rhodium-catalyzed carboxylation of aromatic compounds was carried out to clarify the unique characteristics of this reaction.
Pharmacotherapy in Psychiatric Disorders of Children: Current Evidence and Trends
Authors: Kölch M. , Plener P.
Published: October 2016

Pharmacotherapeutic interventions are available for most psychiatric disorders in children. Evidence for these interventions varies, depending on the targeted disorders. For attention-deficit/hyperactivity disorder, a sound database on efficacy and safety of medication exists. For other common disorders or psychopathological phenomena like disruptive behavior, anxiety disorders, depressive disorders, or autism, data on efficacy and safety are much scarcer. This selective review aims to provide an overview about current psychopharmacological interventions in child and adolescent psychiatry. The literature indicates either a lower efficacy than other interventions or less beneficial effects compared to possible adverse events in these cases. Most guidelines recommend psychopharmacotherapy in children to be embedded in a psychosocial or therapeutic intervention plan. Decision for medication depends on the severity of symptoms, chronicity, and, most important, impairment of the child in academic performance, family relationships, and everyday life. The high rates of off-label use in the age group of children are often due to a lack of market authorization studies less indicative of low efficacy. As adverse events need to be monitored closely, pharmacotherapy should mainly be restricted to experienced mental health care providers.
Diagnostics for molybdenum and tungsten erosion and transport in NSTX-U
Authors: Scotti F. , Soukhanovskii V. A. , Weller M. E.
Published: October 2016

A comprehensive set of spectroscopic diagnostics is planned in the National Spherical Torus Experiment Upgrade to connect measurements of molybdenum and tungsten divertor sources to scrape-off layer (SOL) and core impurity transport, supporting the installation of high-Z plasma facing components which is scheduled to begin with a row of molybdenum tiles. Imaging with narrow-bandpass interference filters and high-resolution spectroscopy will be coupled to estimate divertor impurity influxes. Vacuum ultraviolet and extreme ultraviolet spectrometers will allow connecting high-Z sources to SOL transport and core impurity content. The high-Z diagnostics suite complements the existing measurements for low-Z impurities (carbon and lithium), critical for the characterization of sputtering of high-Z materials.
Formation and properties of high-dose nitrogen implanted epitaxially grown Gd2O3 on silicon
Authors: Joseph A. , Tetzlaff D. , Schmidt J. , Böttger R. , Wietler T. F. , Osten H. J.
Published: October 2016

The effects of nitrogen incorporation by high-dose ion implantation in epitaxial Gd2O3 films on Si(111) followed by annealing have been investigated. Nitrogen incorporation is believed to occur by filling the oxygen vacancies or by removing hydroxyl group ions in gadolinium oxide (Gd2O3). The nitrogen content in the oxide layer has been altered by changing the implantation dose. The impact of nitrogen incorporation on Gd-O bonding is studied using X-ray photoelectron spectroscopy. A shift in the Gd and O peak positions indicate the presence of nitrogen in the layer. Raman spectroscopy reveals heavy structural changes. The newly appearing structure is crystalline, but not in agreement with either the known bixbyite (Gd2O3) or rocksalt (GdN) structure. Electron microscopic investigations reveal the formation of cracks and small areas with lower densities or even voids. That structure exhibits similarities with transmission electron microscopy images of gadolinium nitride (GdN) layers. The electronic band gap of Gd2O3 estimated from O1s plasmon energy loss measurements was found to decrease significantly by the incorporation of nitrogen. Reduction in the valence band and conduction band offset is obtained as a function of implantation dose.
Seamless measurement technology of transient signals based on approximate entropy
Authors: Jiang Jun , Tian Shulin , Guo Lianping , Huang Wuhuang
Published: October 2016

The acquisition of waveforms and the analysis of transient characteristics of signals are the fundamental tasks for time-domain measurement, while the reduction of the measuring gap till seamless measurement is extremely important to the acquisition, measurement, and analysis of transient signals. This paper, aimed at the seamless time-domain measurement of non-stationary transient signals, proposes an approximate entropy-based characteristic signal extraction algorithm on the basis of information entropy theories. The algorithm quantitatively describes the complexity (amount of information) of sampled signals using the approximate entropy value, self-adaptively captures characteristic signals under the control of the approximate entropy in real time, extracts the critical or useful information, and removes redundant or useless information so as to reduce the time consumption of processing data and displaying waveforms and realize the seamless time-domain measurement of transient signals finally. Experimental results show that the study could provide a new method for the design of electronic measuring instrument with seamless measurement capability.
Time-independent states of a non-neutral plasma diode when emitted electrons are partially turned around by a transverse magnetic field
Authors: Pramanik Sourav , Kuznetsov V. I. , Gerasimenko A. B. , Chakrabarti Nikhil
Published: October 2016

An analytical study is presented on the steady states of a plasma diode that is uniformly occupied by infinitely massive ions of constant density and driven by a cold electron beam in the presence of an external transverse magnetic field. In contrast to our previous work [Pramanik et al., Phys. Plasmas 23, 062118 (2016)], here, we investigate the case when electrons are reflected back to the emitter by the magnetic field for arbitrary values of the neutralization parameter. Using the emitter electric field as a characteristic parameter, the steady-state solutions have been evaluated for the specific values of the diode gap, applied voltage, neutralization parameter, and magnetic field strength. It was found that unlike vacuum diodes (e.g., the Bursian diode), steady state solutions also exist for negative values of the emitter field strength. In case of the Bursian diode, only a single type of solutions (Bursian branches) was observed. However, for the Pierce diode, the new family of solutions appeared along with the Bursian ones. In the absence of the external magnetic field as well as when it is weak, the potential distribution shows a wavy nature. However, when the Larmor radius was ten times the beam Debye length, the wavy potential profile and non-Bursian branches disappeared. Based on this phenomenon, a non-neutral diode can be used to operate fast electronic switches.
Nonlinear effects in an acoustic metamaterial with simultaneous negative modulus and density
Authors: Li Yifeng , Lan Jun , Li Baoshun , Liu Xiaozhou , Zhang Jiashu
Published: October 2016

Nonlinear effects in an acoustic metamaterial with simultaneous negative modulus and density based on Helmholtz resonators and membranes periodically distributed along a pipe are studied theoretically. Analyses of the transmission coefficient and dispersion relation of the composite system are realized using the acoustic transmission line method and Bloch theory, respectively. Due to the nonlinearities of the Helmholtz resonators and membranes, the acoustic wave propagation properties vary with the different incident acoustic intensities, and the frequency band gaps of the transmission coefficient are amplitude dependent. The nonlinearities shift the double negative pass band into the adjacent modulus negative forbidden band and transform the metamaterial from an acoustic insulator into an acoustic conductor, leading to some new potential acoustic applications.
Characterization of spin-orbit fields in InGaAs quantum wells
Authors: Henn T. , Czornomaz L. , Salis G.
Published: October 2016

Coherent electron spin dynamics in 10-nm-wide InGaAs/InAlAs quantum wells is studied from 10 K to room temperature using time-resolved Kerr rotation. The spin lifetime exceeds 1 ns at 10 K and decreases with temperature. By varying the spatial overlap between pump and probe pulses, a diffusive velocity is imprinted on the measured electron spins and a spin precession in the spin-orbit field is measured. A Rashba symmetry of the spin-orbit interaction is determined. By comparing the spatial precession frequency gradient with the spin decay rate, an upper limit for the Rashba coefficients α of 2 × 10−12 eVm is estimated.
Investigations on the emission in the extreme ultraviolet of a pseudospark based discharge light source
Authors: Bergmann Klaus , Vieker Jochen , von Wezyk Alexander
Published: October 2016

A new concept of a discharge based extreme ultraviolet radiation source is presented. This concept is based on an electrode system that consists of two consecutive pseudospark discharge stages. The first stage is used to create a pinch plasma as emitter in the extreme ultraviolet and soft X-ray range and the second stage is used as a high current switch between the storage capacity and the first stage. First results on the emission characteristics for the working gases nitrogen, krypton, and xenon, with focus on the emission at 2.88 nm, 6–7 nm, and around 13.5 nm, respectively, are disclosed under the aspect of the access to a larger discharge parameter range. It is shown that this increased range opens a path to a higher spectral peak brightness.
Extinction efficiency of “elastic–sheet” beams by a cylindrical (viscous) fluid inclusion embedded in an elastic medium and mode conversion—Examples of nonparaxial Gaussian and Airy beams
Authors: Mitri F. G.
Published: October 2016

Stemming from the law of the conservation of energy in an elastic medium, this work extends the scope of the previous analysis for a scatterer immersed in a nonviscous liquid [F. G. Mitri, Ultrasonics 62, 20–26 (2015)] to the case of a (viscous) fluid circular cylinder cross-section encased in a homogeneous, isotropic, elastic matrix. Analytical expressions for the absorption, scattering, and extinction efficiencies (or cross-sections) are derived for “elastic-sheets” (i.e., finite beams in 2D propagating in elastic media) of arbitrary wavefront, in contrast to the ideal case of plane waves of infinite extent. The mathematical expressions are formulated in generalized partial-wave series expansions in cylindrical coordinates involving the beam-shape coefficients of finite elastic-sheet beams with arbitrary wavefront, and the scattering coefficients of the fluid cylinder encased in the elastic matrix. The analysis shows that in elastodynamic scattering, both the scattered L-wave as well as the scattered T-wave contribute to the time-averaged scattered efficiency (or power). However, the extinction efficiency only depends on the scattering coefficients characterizing the same type (L or T) as the incident wave. Numerical computations for the (non-dimensional energy) efficiency factors such as the absorption, scattering, and extinction efficiencies of a circular cylindrical viscous fluid cavity embedded in an elastic aluminum matrix are performed for nonparaxial focused Gaussian and Airy elastic-sheet beams with arbitrary longitudinal and transverse normally-polarized (shear) wave incidences in the Rayleigh and resonance regimes. A series of elastic resonances are manifested in the plots of the efficiencies as the non-dimensional size parameters for the L- and T-waves are varied. As the beam waist for the nonparaxial Gaussian beam increases, the plane wave result is recovered, while for a tightly focused wavefront, some of the elastic resonances can be suppressed. Moreover, the efficiencies for the embedded circular viscous fluid cylinder in the field of an Airy elastic-sheet display a spatial parabolic (nonlinear) type of absorption, scattering, and extinction, representative of the intrinsic property of the curved accelerating beam in the elastic matrix. The present analysis provides an improved method for the computations of energy efficiency factors in elastodynamics for finite beams in 2D, which can be used as a priori information in the direct or inverse characterization of the mechanical properties of cylindrical fiber-reinforced materials, pipes, vessels, etc., embedded in an elastic medium.
The near constant loss dynamic mode in metallic glass
Authors: Jiang H. Y. , Luo P. , Wen P. , Bai H. Y. , Wang W. H. , Pan M. X.
Published: October 2016

The near constant loss (NCL) in relaxation spectra is a crucial dynamic phenomenon for glass-forming materials, while its underlying mechanism remains unclear and is hard to study due to the absence of characteristic time scale. We define a characteristic crossover point from both the dynamic mechanical measurements and the quasi-static tension experiments in the metallic glasses (MGs), to study the transition regime, where the NCL dynamics terminates and evolves to the initiation of the β-relaxation. It is found that such transition shows an apparent activation energy well below that of the β-relaxation. Our results also show the concomitant change of the crossover points and the NCL with aging and provide a cursory physical picture on how the NCL occurs, decays and evolves to the β- and α-relaxations in MGs.
Negative activation energy and dielectric signatures of excitons and excitonic Mott transitions in quantum confined laser structures
Authors: Bhunia Amit , Bansal Kanika , Henini Mohamed , Alshammari Marzook S. , Datta Shouvik
Published: October 2016

Mostly, optical spectroscopies are used to investigate the physics of excitons, whereas their electrical evidences are hardly explored. Here, we examined a forward bias activated differential capacitance response of GaInP/AlGaInP based multi-quantum well laser diodes to trace the presence of excitons using electrical measurements. Occurrence of “negative activation energy” after light emission is understood as thermodynamical signature of steady state excitonic population under intermediate range of carrier injections. Similar corroborative results are also observed in an InGaAs/GaAs quantum dot laser structure grown by molecular beam epitaxy. With increasing biases, the measured differential capacitance response slowly vanishes. This represents gradual Mott transition of an excitonic phase into an electron-hole plasma in a GaInP/AlGaInP laser diode. This is further substantiated by more and more exponentially looking shapes of high energy tails in electroluminescence spectra with increasing forward bias, which originates from a growing non-degenerate population of free electrons and holes. Such an experimental correlation between electrical and optical properties of excitons can be used to advance the next generation excitonic devices.
Creating a new investment pool for innovative health systems research
Authors: Laba Tracey-Lea , Patel Anushka , Jan Stephen
Published: October 2016

Recent trends in health research funding towards ‘safe bets’ is discouraging investment into the development of health systems interventions and choking off a vital area of policy-relevant research. This paper argues that to encourage investment into innovative and perceivably riskier health systems research, researchers need to create more attractive business cases by exploring alternative approaches to the design and evaluation of health system interventions. At the same time, the creation of dedicated funding opportunities to support this work, as well as for relevant early career researchers, is needed.
Priming anoestrous Corriedale ewes with progesterone and gonadotrophin-releasing hormone causes cervical tissue remodelling due to metalloproteinase-2 (MMP-2) activity
Authors: Rodríguez-Piñón M. , Tasende C. , Genovese P. , Bielli A. , Casuriaga D. , Garófalo E. G.
Published: October 2016

The aim was to obtain experimental evidence of cervical collagen degradation in anoestrous Corriedale adult ewes induced to ovulate with progesterone (P) and gonadotrophin-releasing hormone (GnRH), at the expected time of induced ovulation and early luteal phase. In Experiment 1, anoestrous ewes were treated with P for 10 days (P, n = 4), with nine micro-doses of GnRH followed by a GnRH bolus injection (GnRH, n = 4) or with P plus GnRH treatments (P+GnRH, n = 3), and cervices were obtained either without treatment (A, n = 4), when P was removed, or 24 h after the GnRH bolus injection. In Experiment 2, cervices were obtained 1 (group P+GnRH, n = 5) or 5 (P+GnRH 5, n = 6) days after the GnRH bolus injection with P pretreatment. MMP-2 activity was detected in all samples; however, MMP-9 activity was only detected in 15% of the samples. The activity of the latent (L) form of MMP-2 in the cranial zone of group A was higher than in the cranial zone of groups P, GnRH and P+GnRH, and was also higher than that in the caudal zone of the same group (P < 0.05). The collagen concentration was lower in group P+GnRH 1 than in group P+GnRH 5 (P < 0.04). The activity of the activated (A) form of MMP-2 and the A/L MMP-2 ratio were higher in group P+GnRH 1 than in group P+GnRH 5 (P < 0.05). Data suggest that the L form of MMP-2 was expressed mainly in a constitutive form in the cervix of anoestrous ewes and that an oestrogen-dependent activation mechanisms due to the GnRH treatment may be responsible for the lowest collagen content at the moment of the induced ovulation. This work provides evidence about cervical collagen remodelling in anoestrous ewes treated with P + GnRH.
Parafoveal preview effects depend on both preview plausibility and target predictability
Authors: Veldre Aaron , Andrews Sally
Published: October 2016

Recent studies using the boundary paradigm have shown that readers benefit from a parafoveal preview of a plausible continuation of the sentence. This plausibility preview effect occurs irrespective of the semantic or orthographic relatedness of the preview and target word, suggesting that it depends on the degree to which a preview word fits the preceding context. The present study tested this hypothesis by examining the impact of contextual constraint on processing a plausible word in the parafovea. Participants’ eye movements were recorded as they read sentences in which a target word was either highly predictable or unpredictable. The boundary paradigm was used to compare predictable, unpredictable, and implausible previews. The results showed that target predictability significantly modulated the effects of identical and plausible previews. Identical previews yielded significantly more benefit than plausible previews for highly predictable targets, but for unpredictable targets a plausible preview was as beneficial as an identical preview. The results shed light on the role of contextual predictability in early lexical processing. Furthermore, these data support the view that readers activate a set of appropriate words from the preceding sentence context, prior to the presentation of the target word.
Analysis of diffusion in curved surfaces and its application to tubular membranes
Authors: Klaus Colin James Stockdale , Raghunathan Krishnan , DiBenedetto Emmanuele , Kenworthy Anne K.
Published: October 2016

Diffusion of particles in curved surfaces is inherently complex compared with diffusion in a flat membrane, owing to the nonplanarity of the surface. The consequence of such nonplanar geometry on diffusion is poorly understood but is highly relevant in the case of cell membranes, which often adopt complex geometries. To address this question, we developed a new finite element approach to model diffusion on curved membrane surfaces based on solutions to Fick’s law of diffusion and used this to study the effects of geometry on the entry of surface-bound particles into tubules by diffusion. We show that variations in tubule radius and length can distinctly alter diffusion gradients in tubules over biologically relevant timescales. In addition, we show that tubular structures tend to retain concentration gradients for a longer time compared with a comparable flat surface. These findings indicate that sorting of particles along the surfaces of tubules can arise simply as a geometric consequence of the curvature without any specific contribution from the membrane environment. Our studies provide a framework for modeling diffusion in curved surfaces and suggest that biological regulation can emerge purely from membrane geometry.
The phospholipid flippase ATP9A is required for the recycling pathway from the endosomes to the plasma membrane
Authors: Tanaka Yoshiki , Ono Natsuki , Shima Takahiro , Tanaka Gaku , Katoh Yohei , Nakayama Kazuhisa , Takatsu Hiroyuki , Shin Hye-Won
Published: October 2016

Type IV P-type ATPases (P4-ATPases) are phospholipid flippases that translocate phospholipids from the exoplasmic (or luminal) to the cytoplasmic leaflet of lipid bilayers. In Saccharomyces cerevisiae, P4-ATPases are localized to specific subcellular compartments and play roles in compartment-mediated membrane trafficking; however, roles of mammalian P4-ATPases in membrane trafficking are poorly understood. We previously reported that ATP9A, one of 14 human P4-ATPases, is localized to endosomal compartments and the Golgi complex. In this study, we found that ATP9A is localized to phosphatidylserine (PS)-positive early and recycling endosomes, but not late endosomes, in HeLa cells. Depletion of ATP9A delayed the recycling of transferrin from endosomes to the plasma membrane, although it did not affect the morphology of endosomal structures. Moreover, depletion of ATP9A caused accumulation of glucose transporter 1 in endosomes, probably by inhibiting their recycling. By contrast, depletion of ATP9A affected neither the early/late endosomal transport and degradation of epidermal growth factor (EGF) nor the transport of Shiga toxin B fragment from early/recycling endosomes to the Golgi complex. Therefore ATP9A plays a crucial role in recycling from endosomes to the plasma membrane.
Prevalence of Endometriosis During Abdominal or Laparoscopic Hysterectomy for Chronic Pelvic Pain
Authors: Mowers Erika L. , Lim Courtney S. , Skinner Bethany , Mahnert Nichole , Kamdar Neil , Morgan Daniel M. , As-Sanie Sawsan
Published: October 2016

(Abstracted from Obstet Gynecol 2016;127:1045–1053)

Chronic pelvic pain is common in reproductive-aged women. A large number of women with chronic pelvic pain or endometriosis undergo hysterectomy: 10% to 32% for chronic pelvic pain and 5% to 19% for endometriosis.
“The More the Better” Paradox of Antenatal Ultrasound Examinations in Low-Risk Pregnancy
Authors: Chiossi Giuseppe , Palomba Stefano , Balduzzi Sara , Costantine Maged M. , Falbo Angela I. , La Sala Giovanni B.
Published: October 2016

(Abstracted from Am J Perinatol 2016;33:646–657)

The increasing rates of cesarean delivery (CD) worldwide have caused concern regarding maternal risks in subsequent pregnancies, higher neonatal and childhood morbidity, and increased health care costs. The identification of modifiable risk factors for CD and operative vaginal deliveries has therefore assumed importance.