bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolutionary dynamics and genomic features of the Elizabethkingia anophelis 2015 to 2016 Wisconsin outbreak strain
Authors: Perrin Amandine , Larsonneur Elise , Nicholson Ainsley C. , Edwards David J. , Gundlach Kristin M. , Whitney Anne M. , Gulvik Christopher A. , Bell Melissa E. , Rendueles Olaya , Cury Jean , Hugon Perrine , Clermont Dominique , Enouf Vincent , Loparev Vladimir , Juieng Phalasy , Monson Timothy , Warshauer David , Elbadawi Lina I. , Walters Maroya Spalding , Crist Matthew B. , Noble-Wang Judith , Borlaug Gwen , Rocha Eduardo P. C. , Criscuolo Alexis , Touchon Marie , Davis Jeffrey P. , Holt Kathryn E. , McQuiston John R. , Brisse Sylvain
Published: May 2017

An atypically large outbreak of Elizabethkingia anophelis infections occurred in Wisconsin. Here we show that it was caused by a single strain with thirteen characteristic genomic regions. Strikingly, the outbreak isolates show an accelerated evolutionary rate and an atypical mutational spectrum. Six phylogenetic sub-clusters with distinctive temporal and geographic dynamics are revealed, and their last common ancestor existed approximately one year before the first recognized human infection. Unlike other E. anophelis, the outbreak strain had a disrupted DNA repair mutY gene caused by insertion of an integrative and conjugative element. This genomic change probably contributed to the high evolutionary rate of the outbreak strain and may have increased its adaptability, as many mutations in protein-coding genes occurred during the outbreak. This unique discovery of an outbreak caused by a naturally occurring mutator bacterial pathogen provides a dramatic example of the potential impact of pathogen evolutionary dynamics on infectious disease epidemiology.
Spin-orbit torque-driven skyrmion dynamics revealed by time-resolved X-ray microscopy
Authors: Woo Seonghoon , Song Kyung Mee , Han Hee-Sung , Jung Min-Seung , Im Mi-Young , Lee Ki-Suk , Song Kun Soo , Fischer Peter , Hong Jung-Il , Choi Jun Woo , Min Byoung-Chul , Koo Hyun Cheol , Chang Joonyeon
Published: May 2017

Magnetic skyrmions are topologically protected spin textures with attractive properties suitable for high-density and low-power spintronic device applications. Much effort has been dedicated to understanding the dynamical behaviours of the magnetic skyrmions. However, experimental observation of the ultrafast dynamics of this chiral magnetic texture in real space, which is the hallmark of its quasiparticle nature, has so far remained elusive. Here, we report nanosecond-dynamics of a 100nm-diameter magnetic skyrmion during a current pulse application, using a time-resolved pump-probe soft X-ray imaging technique. We demonstrate that distinct dynamic excitation states of magnetic skyrmions, triggered by current-induced spin–orbit torques, can be reliably tuned by changing the magnitude of spin–orbit torques. Our findings show that the dynamics of magnetic skyrmions can be controlled by the spin–orbit torque on the nanosecond time scale, which points to exciting opportunities for ultrafast and novel skyrmionic applications in the future.
TAL effector driven induction of a SWEET gene confers susceptibility to bacterial blight of cotton
Authors: Cox Kevin L. , Meng Fanhong , Wilkins Katherine E. , Li Fangjun , Wang Ping , Booher Nicholas J. , Carpenter Sara C. D. , Chen Li-Qing , Zheng Hui , Gao Xiquan , Zheng Yi , Fei Zhangjun , Yu John Z. , Isakeit Thomas , Wheeler Terry , Frommer Wolf B. , He Ping , Bogdanove Adam J. , Shan Libo
Published: May 2017

Transcription activator-like (TAL) effectors from Xanthomonas citri subsp. malvacearum (Xcm) are essential for bacterial blight of cotton (BBC). Here, by combining transcriptome profiling with TAL effector-binding element (EBE) prediction, we show that GhSWEET10, encoding a functional sucrose transporter, is induced by Avrb6, a TAL effector determining Xcm pathogenicity. Activation of GhSWEET10 by designer TAL effectors (dTALEs) restores virulence of Xcm avrb6 deletion strains, whereas silencing of GhSWEET10 compromises cotton susceptibility to infections. A BBC-resistant line carrying an unknown recessive b6 gene bears the same EBE as the susceptible line, but Avrb6-mediated induction of GhSWEET10 is reduced, suggesting a unique mechanism underlying b6-mediated resistance. We show via an extensive survey of GhSWEET transcriptional responsiveness to different Xcm field isolates that additional GhSWEETs may also be involved in BBC. These findings advance our understanding of the disease and resistance in cotton and may facilitate the development cotton with improved resistance to BBC.
Sublingual house dust mite immunotherapy has no impact on decrease of circulating erythrocytes upon airway allergen challenge in allergic rhinitis
Authors: Jordakieva Galateja , Kundi Michael , Lemell Patrick , Zieglmayer René , Zieglmayer Petra , Godnic-Cvar Jasminka , Jensen-Jarolim Erika
Published: May 2017

House dust mite (HDM) allergy is a predominant cause for perennial allergic rhinitis (AR) in Europe. We recently reported that circulating erythrocyte numbers decrease after airway allergen challenge in a murine asthma model and in grass-pollen sensitized AR subjects. Consequently, we aimed to evaluate these findings in HDM sensitized AR subjects and the influence of preceding allergen immunotherapy. Seventy-seven (age 26.8 ± 7.3 years; 54.5% female) HDM-allergic rhinitis subjects previously enrolled in a randomized, monocentric sublingual immunotherapy (SLIT) trial at the Vienna Challenge Chamber (VCC) were included. Subjects had either received placebo (n = 22), low-dose HDM (n = 29) or high-dose HDM specific sublingual immunotherapy (n = 26) daily for 24 weeks. Blood sampling was performed before and after 6 hours of HDM allergen exposure. Overall, specific airway allergen challenge resulted in a significant decrease in circulating erythrocytes and hematocrit (p < 0.001), and elevation of leukocytes (p < 0.001), particularly segmented neutrophils (p < 0.001). Gender had no significant effect on the observed changes in circulating blood cells. Erythrocytes decreased and neutrophil counts increased significantly after airway allergen challenge regardless of preceding immunotherapy. These findings imply a rapid systemic mobilization of neutrophils occurring within immediate type hypersensitivity response upon a specific allergen challenge, which is possibly inversely linked with the erythrocyte numbers.
A Benzothiazole Derivative (5g) Induces DNA Damage And Potent G2/M Arrest In Cancer Cells
Authors: Hegde Mahesh , Vartak Supriya V. , Kavitha Chandagirikoppal V. , Ananda Hanumappa , Prasanna Doddakunche S. , Gopalakrishnan Vidya , Choudhary Bibha , Rangappa Kanchugarakoppal S. , Raghavan Sathees C.
Published: May 2017

Chemically synthesized small molecules play important role in anticancer therapy. Several chemical compounds have been reported to damage the DNA, either directly or indirectly slowing down the cancer cell progression by causing a cell cycle arrest. Direct or indirect reactive oxygen species formation causes DNA damage leading to cell cycle arrest and subsequent cell death. Therefore, identification of chemically synthesized compounds with anticancer potential is important. Here we investigate the effect of benzothiazole derivative (5g) for its ability to inhibit cell proliferation in different cancer models. Interestingly, 5g interfered with cell proliferation in both, cell lines and tumor cells leading to significant G2/M arrest. 5g treatment resulted in elevated levels of ROS and subsequently, DNA double-strand breaks (DSBs) explaining observed G2/M arrest. Consistently, we observed deregulation of many cell cycle associated proteins such as CDK1, BCL2 and their phosphorylated form, CyclinB1, CDC25c etc. Besides, 5g treatment led to decreased levels of mitochondrial membrane potential and activation of apoptosis. Interestingly, 5g administration inhibited tumor growth in mice without significant side effects. Thus, our study identifies 5g as a potent biochemical inhibitor to induce G2/M phase arrest of the cell cycle, and demonstrates its anticancer properties both ex vivo and in vivo.
Efficacy and Tolerability of Second and Third Generation Anti-epileptic Drugs in Refractory Epilepsy: A Network Meta-Analysis
Authors: Zhuo Chuanjun , Jiang Ronghuan , Li Gongying , Shao Mingjing , Chen Ce , Chen Guangdong , Tian Hongjun , Li Jie , Xue Rong , Jiang Deguo
Published: May 2017

This study was proposed to compare the relative efficacy and tolerability of the second and third generation AEDs for refractory epilepsy. The 50% responder rate (RR) was selected as the efficacy outcome whereas the incidence of dizziness and somnolence were considered to evaluate the tolerability of AEDs. Odds ratio (OR) and their 95% credible interval (CrI) were obtained using a consistency model and surface under the cumulative ranking curve (SUCRA) value was calculated to rank AEDs. Topiramate appeared to be significantly more effective than placebo, eslicarbazepine acetate, perampanel, pregabalin, zonisamide, gabapentin and lamotrigine with respect to the 50% RR (all OR > 1). Patients who were managed by eslicarbazepine acetate, perampanel, oxcarbazepine, topiramate and pregabalin were more likely to suffer from dizziness compared to those who receive placebo (all OR > 1). Perampanel, topiramate and pregabalin were related to elevated risks of somnolence compared to placebo (all OR > 1). Moreover, topiramate ranked highest with respect to 50% RR (SUCRA = 0.968) whereas levetiracetam appeared to have balanced efficacy and tolerability (SUCRA = 0.769, 0.743, 0.604 and 0.659). In conclusion, topiramate was the most efficacious AED, while levetiracetam was able to provide patients with balanced efficacy and tolerability.
Potent anti-cancer effects of less polar Curcumin analogues on gastric adenocarcinoma and esophageal squamous cell carcinoma cells
Authors: Alibeiki Fatemeh , Jafari Naser , Karimi Maryam , Peeri Dogaheh Hadi
Published: May 2017

Curcumin and its chalcone derivatives inhibit the growth of human cancer cells. It is reported that replacement of two OH groups in curcumin with less polar groups like methoxy increases its anti-proliferative activity. In this study, we explored benzylidine cyclohexanone derivatives with non-polar groups, to see if they possess increased anti-cancer activity. Novel 2,6-bis benzylidine cyclohexanone analogues of curcumin were synthesized, and their inhibitory effects on gastric adenocarcinoma (AGS) and esophageal squamous cell carcinoma (KYSE30) cancer cells were studied using an MTT assay. Cell apoptosis was detected by EB/AO staining, and cell cycle was analyzed by flow cytometry. Real-time PCR was performed for gene expression analysis. All synthesized analogues were cytotoxic toward gastric and esophageal cancer cells and showed lower IC50 values than curcumin. Treatment with 2,6-Bis-(3-methoxy-4-propoxy-benzylidene)-cyclohexanone (BM2) was 17 times more toxic than curcumin after 48 h incubation. All novel compounds were more effective than curcumin in apoptosis induction and cell cycle arrest at G1 phase. These results suggest that less polar analogues of curcumin have potent cytotoxicity in vitro. However, they need to be investigated further, especially with animal tumor models, to confirm their chemotherapeutic activity in vivo.
Molecular alignment in degenerated dissociation channels in strong laser fields
Authors: Lai Wei , Heins Alan , Guo Chunlei
Published: May 2017

In this work, we study strong-field molecular alignment in, for the first time, degenerated channels following the same charged states of molecules. By measuring the angular distribution of dissociation fragments from two degenerated N+ + N+ channels of N2, we observe an opposite angular distribution development in these two channels, one expanding and one contracting, when the laser intensity increases. Our further study shows that the expanding channel comes from a nonsequential transition, while the contracting channel involves a sequential transition. We also study the time sequence of the sequential and nonsequential transitions and find that the opposite angular distribution development is due to the different degrees of molecular alignment in these two degenerated channels.
Dynamic control of coherent pulses via destructive interference in graphene under Landau quantization
Authors: Yang Wen-Xing , Chen Ai-Xi , Xie Xiao-Tao , Liu Shaopeng , Liu Shasha
Published: May 2017

We analyze the destructive interference in monolayer graphene under Landau quantization in a time-dependent way by using the Bloch-Maxwell formalism. Based on this analysis, we investigate the dynamics control of an infrared probe and a terahertz (THz) switch pulses in graphene. In presence of the THz switch pulse, the destructive interference take places and can be optimized so that the monolayer graphene is completely transparent to the infrared probe pulse. In absence of the THz switch pulse, however, the infrared probe pulse is absorbed due to such a interference does not take place. Furthermore, we provide a clear physics insight of this destructive interference by using the classical dressed-state theory. Conversely, the present model may be rendered either absorbing or transparent to the THz switch pulse. By choosing appropriate wave form of the probe and switch pulses, we show that both infrared probe and THz switch pulses exhibit the steplike transitions between absorption and transparency. Such steplike transitions can be used to devise a versatile quantum interference-based solid-state optical switching with distinct wave-lengths for optical communication devices.
The agglomeration, coalescence and sliding of nanoparticles, leading to the rapid sintering of zirconia nanoceramics
Authors: Kocjan Andraž , Logar Manca , Shen Zhijian
Published: May 2017

Conventional sintering is a time- and energy-consuming process used for the densification of consolidated particles facilitated by atomic diffusion at high temperatures. Nanoparticles, with their increased surface free energy, can promote sintering; however, size reduction also promotes agglomeration, so hampering particle packing and complete densification. Here we show how the ordered agglomeration of zirconia primary crystallites into secondary particle assemblies ensures their homogeneous packing, while also preserving the high surface energy to higher temperatures, increasing the sintering activity. When exposed to intense electromagnetic radiation, providing rapid heating, the assembled crystallites are subjected to further agglomeration, coalescence and sliding, leading to rapid densification in the absence of extensive diffusional processes, cancelling out the grain growth during the initial sintering stages and providing a zirconia nanoceramic in only 2 minutes at 1300 °C.
Determinants of Quantitative Optical Coherence Tomography Angiography Metrics in Patients with Diabetes
Authors: Tang Fang Yao , Ng Danny S. , Lam Alexander , Luk Fiona , Wong Raymond , Chan Carmen , Mohamed Shaheeda , Fong Angie , Lok Jerry , Tso Tiffany , Lai Frank , Brelen Marten , Wong Tien Y. , Tham Clement C. , Cheung Carol Y.
Published: May 2017

Early microvascular damage in diabetes (e.g. capillary nonperfusion and ischemia) can now be assessed and quantified with optical coherence tomography-angiography (OCT-A). The morphology of vascular tissue is indeed affected by different factors; however, there is a paucity of data examining whether OCT-A metrics are influenced by ocular, systemic and demographic variables in subjects with diabetes. We conducted an observational cross-sectional study and included 434 eyes from 286 patients with diabetes. Foveal avascular zone (FAZ) area, FAZ circularity, total and parafoveal vessel density (VD), fractal dimension (FD), and vessel diameter index (VDI) from the superficial capillary plexus OCT-angiogram were measured by a customized automated image analysis program. We found that diabetic retinopathy (DR) severity was associated with increased FAZ area, decreased FAZ circularity, lower VD, lower FD, and increased VDI. Enlarged FAZ area was correlated with shorter axial length and thinner central subfield macular thickness. Decreased FAZ circularity was correlated with a reduction in visual function. Decreased VD was correlated with thinner macular ganglion-cell inner plexiform layer. Increased VDI was correlated with higher fasting glucose level. We concluded that the effects of ocular and systemic factors in diabetics should be taken into consideration when assessing microvascular alterations via OCT-A.
Combinatorial Delivery of Dual and Triple TLR Agonists via Polymeric Pathogen-like Particles Synergistically Enhances Innate and Adaptive Immune Responses
Authors: Madan-Lala Ranjna , Pradhan Pallab , Roy Krishnendu
Published: May 2017

Despite decades of research very few vaccine-adjuvants have received FDA approval. Two fundamental challenges plague clinical translation of vaccine-adjuvants: reducing acute toxicities that result from systemic diffusion of many soluble adjuvants, and delivering multiple adjuvants at the same time to mimic the synergistic immune-stimulation of pathogens, while being safe. In order to address these barriers, we evaluated combinations of four clinically relevant immune-agonists, specifically Toll-like receptor (TLR) ligands, using biodegradable, polymer microparticles. We tested them alone and in combinations of 2 or 3, for a total of 10 unique conditions. We evaluated primary bone-marrow-derived Dendritic Cell phenotypes and functionality, and identified several synergistic combinations. We picked a dual and a triple adjuvant combination, TLR4/TLR9 and TLR4/TLR7/TLR9, for further evaluation and found that both combinations promoted antigen cross-presentation in vitro. Studies in mice using the model antigen Ovalbumin, showed that both combinations enhanced lymph node germinal center and T follicular helper cell responses. The triple adjuvant combination showed increased antigen-specific antibody titer with an overall balanced Th1/Th2 response, while the dual combination promoted Th1-polarized IgG responses. Our results show how polymeric particulate-carriers can be adopted to safely deliver combinatorial adjuvants and selectively synergize specific types of immune responses for vaccine applications.
Adaptation to Progressive Additive Lenses: Potential Factors to Consider
Authors: Alvarez Tara L. , Kim Eun H. , Granger-Donetti Bérangère
Published: May 2017

People develop presbyopia as part of the normal aging process. Most presbyopes adapt to progressive additive lens (PALs), while others do not. This investigation sought to determine whether the ability to modify disparity vergence or phoria was correlated to PALs adaptation. In experiment 1, a double-step paradigm quantified the ability to modify convergence responses in sixteen presbyopes. In experiment 2, thirty-one incipient presbyopes participated in a 5-minute sustained fixation task to evoke phoria adaptation where the magnitude and rate of phoria adaptation were measured. Then, the experiment was repeated after wearing PALs for one month. Linear regression analyses were conducted between the following parameters: near point of convergence, positive fusional vergence at near, vergence facility, net change in the magnitude of phoria adaptation, and the rate of phoria adaptation. The ability to change convergence average peak velocity was significantly greater (p < 0.03) in presbyopic PALs adapters compared to presbyopic PALs non-adapters. The rate of phoria adaptation and vergence facility were significantly greater (p < 0.03) in incipient presbyopic PALs adapters compared to incipient presbyopic PALs non-adapters. Vergence facility and the rate of phoria adaptation may have potential clinical utility in differentiating which patients may adapt to PALs and which ones will have more difficulty.
SPRpages – Getting a Feeling for the Curves
Authors: Marquart J. Arnoud
Published: May 2017

A thorough understanding of how biomolecular interaction curves should look like is essential when evaluating surface plasmon resonance experimental data. This chapter discusses the shape of the biomolecular interaction curve, mentions crucial properties of the interaction curve and shows deviations from the ideal situation. In addition, the experimental conditions are discussed to avoid sub-optimal interaction curves and tests are presented to detect sub-optimal situations. Because the interaction kinetics can vary significantly between different interactants, experimental strategies that can be used are outlined for different situations. A small section is dedicated to the fitting of the curves and the validation of the results. Special attention is given to publishing sensorgrams.
Fragment and Low Molecular Weight Compound Analysis
Authors: Karlsson Robert , Karlsson O. , Belcher P.
Published: May 2017

This chapter describes fragment and low molecular weight compound analysis and covers the screening and characterization of small-molecule binding to protein targets. Screening and characterization can be performed using different assay formats. How do these formats differ from each other and what information do they provide? How should experiments be designed? Are there special considerations for immobilization? Is sample handling and interpretation of signal levels different with low molecular weight analytes? How can screening data be analyzed? How can binders be validated? What is there to consider in the kinetic analysis of small molecules? All of these questions are considered and attempts are made to provide some answers.
Understanding and improving aggregated gold nanoparticle/dsDNA interactions by molecular spectroscopy and deconvolution methods
Authors: Carnerero Jose M. , Jimenez-Ruiz Aila , Grueso Elia M. , Prado-Gotor Rafael
Published: May 2017

The interaction between two anionic substrates (gold nanoparticles and calf thymus DNA) is explored, as well as the influence of NaCl.
ROCK inhibitor Y-27632 attenuated early endothelial dysfunction caused by occupational environmental concentrations of carbon black nanoparticles
Authors: Yan J. Y. , Huang C. C. , Lung S. C. C. , Wang W. C. , Suo G. L. , Lin Y. J. , Lai C. H. , Lin C. H.
Published: May 2017

The unique properties of carbon black nanoparticles (CBNs) make them feasible for new applications and raise concerns about cardiovascular disorders.
Ground-state dioxygen undergoes metal-free [3 + 2]-annulations with allenes and nitrosoarenes under ambient conditions
Authors: Liu Jinxian , Skaria Manisha , Sharma Pankaj , Chiang Yun-Wei , Liu Rai-Shung
Published: May 2017

We report novel [3 + 2]-annulations among ground-state3O2(1 bar), allenes, and nitrosoarenes at low temperatures, efficiently yielding dioxygen-containing oxacycles.
Identification of a conformational heparin-recognition motif on the peptide hormone secretin: key role for cell surface binding
Authors: Quittot Noé , Nguyen Phuong Trang , Nerée Armelle Tchoumi , Lussier Marc P. , Bourgault Steve
Published: May 2017

Secretin is a peptide hormone that exerts pleiotropic physiological functions by specifically binding to its cognate membrane-bound receptor. The membrane catalysis model of peptide–receptor interactions states that soluble peptidic ligands initially interact with the plasma membrane. This interaction increases the local concentration and structures the peptide, enhancing the rate of receptor binding. However, this model does not consider the dense network of glycosaminoglycans (GAGs) at the surface of eukaryotic cells. These sulfated polysaccharide chains are known to sequester numerous proteic signaling molecules. In the present study, we evaluated the interaction between the peptide hormone secretin and sulfated GAGs and its contribution to cell surface binding. Using GAG-deficient cells and competition experiments with soluble GAGs, we observed by confocal microscopy and flow cytometry that GAGs mediate the sequestration of secretin at the cell surface. Isothermal titration calorimetry and surface plasmon resonance revealed that secretin binds to heparin with dissociation constants ranging between 0.9 and 4 μM. By designing secretin derivatives with a restricted conformational ensemble, we observed that this interaction is mediated by the presence of a specific conformational GAG-recognition motif that decorates the surface of the peptide upon helical folding. The present study identifies secretin as a novel GAG-binding polypeptide and opens new research direction on the functional role of GAGs in the biology of secretin.
Exploring Audiologists' Language and Hearing Aid Uptake in Initial Rehabilitation Appointments
Authors: Sciacca Anna , Meyer Carly , Ekberg Katie , Barr Caitlin , Hickson Louise
Published: May 2017

Purpose

The study aimed (a) to profile audiologists' language during the diagnosis and management planning phase of hearing assessment appointments and (b) to explore associations between audiologists' language and patients' decisions to obtain hearing aids.

Method

Sixty-two audiologist–patient dyads participated. Patient participants were aged 55 years or older. Hearing assessment appointments were audiovisually recorded and transcribed for analysis. Audiologists' language was profiled using two measures: general language complexity and use of jargon. A binomial, multivariate logistic regression analysis was conducted to investigate the associations between these language measures and hearing aid uptake.

Results

The logistic regression model revealed that the Flesch–Kincaid reading grade level of audiologists' language was significantly associated with hearing aid uptake. Patients were less likely to obtain hearing aids when audiologists' language was at a higher reading grade level. No associations were found between audiologists' use of jargon and hearing aid uptake.

Conclusions

Audiologists' use of complex language may present a barrier for patients to understand hearing rehabilitation recommendations. Reduced understanding may limit patient participation in the decision-making process and result in patients being less willing to trial hearing aids. Clear, concise language is recommended to facilitate shared decision making.
Metal frame repeater antenna with partial slotted ground for bandwidth enhancement of wristband devices
Authors: Duan Zhu , Xu Li‐Jie , Geyi Wen
Published: May 2017

This work proposes a metal frame wristband antenna for biomedical healthcare monitoring applications. The repeater antenna is supported by printed circuit board (PCB), surrounded by a metal frame with a planar size of 40 mm × 20 mm. By introducing a partial ground with two L‐shaped cuts at the centre of the PCB, wideband performance can be achieved, ranging from 4.0 to 7.2 GHz in free space and 3.4 to 7.3 GHz on human body. For on‐body application, it covers both the interference‐free subset of the unlicensed 3.5–4.5 GHz ultra‐wideband (UWB) and 5.725–5.875 GHz industrial scientific and medical (ISM) band. The UWB band is intended for near field communication with implanted device, while the ISM band is intended for far‐field telemetry with monitoring station. Good agreement is obtained between measurements and simulations.
Non‐linearity in superconducting microstrip open‐ring resonators
Authors: Mostaani Abolfazl , Javadzadeh S. Mohammad Hassan
Published: May 2017

The non‐linear behaviour of the superconducting microstrip open‐ring resonators is computed by an analytical method based on the distributed equivalent circuit model of transmission lines. In fact, the equivalent circuit model of the open‐ring resonator is analysed and relative non‐linearities such as third‐order harmonic generation and third‐order inter‐modulation (IMD3) distortion, are computed by the harmonic balance approach. As an example, the method is applied to a superconducting open‐ring resonator and its IMD3 is obtained and compared with experiment to validate the accuracy of the proposed method. Such approach can considerably save time, cost and memory usage of the simulation and experiments.
Intramolecular Hydroalkoxylation/Reduction and Hydroamination/Reduction of Unactivated Alkynes Using a Silane–Iodine Catalytic System
Authors: Shibuya Masatoshi , Fujita Shoji , Yamamoto Yoshihiko
Published: May 2017

A transition-metal-free silane–iodine catalytic system comprising I2 and Et3SiH promotes intramolecular hydroalkoxylation/reduction and hydroamination/reduction of unactivated alkynes. This system allows the reaction to proceed at room temperature affording 2,4- and 2,5-disubstituted pyrrolidines as well as a 2,3-disubstituted tetrahydrofuran with high diastereoselectivity.
A Rapid and Diastereoselective Synthesis of 2-Deoxy-2-iodo-α-glycosides and its Mechanism for Diastereoselectivity
Authors: Li Chunbao , Yuan Wenjiao , Liu Yali
Published: May 2017

Reductive deiodination of 2-deoxy-2-iodo-glycoside is an efficient and practical approach for the synthesis of 2-deoxyglycosides, which are moieties of bioactive compounds. However, inseparable diastereoisomers are usually formed in the preparation of 2-deoxy-2-iodo-glycosides via glycosylation of glycals with alcohols using current methods. To overcome this problem, a rapid and diastereoselective transformation of glycals and alcohols into 2-deoxy-2-iodo-α-glycosides enabled by I2/PhI(OAc)2 has been developed. 14 glycals, derived from 13 monosaccharides and one disaccharide, diastereoselectively yielded α-glycosides. Only in two cases the diastereoselectivity of the glycosylation was poor. The yields of glycosylation range from 73% to 95%, and the reactions are finished in only five minutes. Investigations for better diastereoselectivity by comparing I2/Ph(OAc)2- with I2/Cu(OAc)2-mediated glycosylations using UV analysis have been conducted.
The asymmetric band structure and electrical behavior of the GdScO3/GaN system
Authors: Iacopetti S. , Shekhter P. , Winter R. , Tromm T. C. U. , Schubert J. , Eizenberg M.
Published: May 2017

III–V nitrides are interesting materials for a very wide variety of electronic and optoelectronic devices. In this study, their interaction with GdScO3 (GSO), a ternary rare earth oxide, is investigated for MOS applications. We compare pulsed laser deposited amorphous and crystalline epitaxial GdScO3 in terms of their band alignment with the underlying GaN substrate and the resulting electrical characteristics of the MOS stack. The crystal structure of GdScO3 and GaN is investigated by means of x-ray diffraction, showing that crystalline oxide is growing epitaxially on GaN. X-ray photoelectron spectroscopy analysis shows a staggered band alignment with a GdScO3-GaN valence band offset of 3.6–3.7 eV, which is reflected in a very asymmetric current-voltage behaviour of the MOS capacitors: breakdown at positive bias, significantly earlier for the crystalline oxide (around 5 MV/cm) compared to the amorphous oxide (around 8 MV/cm), and no breakdown up to a field of −14 MV/cm at negative bias. Transmission electron microscopy images show a crystalline, two-atom thick interface layer between GaN and both crystalline and amorphous GdScO3, which is thought to be an electron barrier between GSO and GaN and a possible source of the staggered band alignment. The electrical behaviour can be exploited for asymmetric nano-electronic devices.
Advanced materials for magnetic cooling: Fundamentals and practical aspects
Authors: Balli M. , Jandl S. , Fournier P. , Kedous-Lebouc A.
Published: May 2017

Over the last two decades, the research activities on magnetocalorics have been exponentially increased, leading to the discovery of a wide category of materials including intermetallics and oxides. Even though the reported materials were found to show excellent magnetocaloric properties on a laboratory scale, only a restricted family among them could be upscaled toward industrial levels and implemented as refrigerants in magnetic cooling devices. On the other hand, in the most of the reported reviews, the magnetocaloric materials are usually discussed in terms of their adiabatic temperature and entropy changes (ΔTad and ΔS), which is not enough to get more insight about their large scale applicability. In this review, not only the fundamental properties of the recently reported magnetocaloric materials but also their thermodynamic performance in functional devices are discussed. The reviewed families particularly include Gd1-xRx alloys, LaFe13-xSix, MnFeP1-xAsx, and R1-xAxMnO3 (R = lanthanide and A = divalent alkaline earth)–based compounds. Other relevant practical aspects such as mechanical stability, synthesis, and corrosion issues are discussed. In addition, the intrinsic and extrinsic parameters that play a crucial role in the control of magnetic and magnetocaloric properties are regarded. In order to reproduce the needed magnetocaloric parameters, some practical models are proposed. Finally, the concepts of the rotating magnetocaloric effect and multilayered magnetocalorics are introduced.
Vertical transport in isotype InAlN/GaN dipole induced diodes grown by molecular beam epitaxy
Authors: Fireman M. N. , Li Haoran , Keller Stacia , Mishra Umesh K. , Speck James S.
Published: May 2017

InAlN dipole diodes were developed and fabricated on both (0001) Ga-Face and 0001¯ N-face oriented GaN on sapphire templates by molecular beam epitaxy. The orientation and direction of the InAlN polarization dipole are functions of the substrate orientation and composition, respectively. Special consideration was taken to minimize growth differences and impurity uptake during growth on these orientations of opposite polarity. Comparison of devices on similarly grown structures with In compositions in excess of 50% reveals that dipole diodes shows poorer forward bias performance and exhibited an increase in reverse bias leakage, regardless of orientation. Similarly, (0001) Ga-face oriented InAlN at a lowered 40% In composition had poor device characteristics, namely, the absence of expected exponential turn on in forward bias. By contrast, at In compositions close to 40%, 0001¯ N-face oriented InAlN devices had excellent performance, with over five orders of magnitude of rectification and extracted barrier heights of 0.53– 0.62 eV; these values are in close agreement with simulation. Extracted ideality factors ranging from 1.08 to 1.38 on these devices are further evidence of their optimal performance. Further discussion focuses on the growth and orientation conditions that may lead to this discrepancy yet emphasizes that with proper design and growth strategy, the rectifying dipole diodes can be achieved with InAlN nitride dipole layers.
Ion cyclotron resonance heating (ICRH) systems for the Keda Mirror with AXisymmetry (KMAX)
Authors: Liu Ming , Yi Hongshen , Lin Munan , Wang Yanpeng , Shi Peiyun , Zheng Jian , Sun Xuan
Published: May 2017

In this paper, we describe the engineering work involved in constructing two ion cyclotron resonance heating (ICRH) systems for use in the Keda Mirror with AXisymmetry tandem mirror experiment. Because they offer an effective and robust heating method, ICRH systems have been widely used in a variety of plasma experiments. The goal of our system is to heat the hydrogen plasma contained in the central cell using the fundamental ion cyclotron frequency. Both systems can deliver a radiofrequency power of ∼120 kW with adjustable operating frequencies that are tuned to be slightly lower than their local ion cyclotron frequencies. Two types of antennas are installed in the central cell in an attempt to launch both slow and fast waves. The heating mechanism is reliant on the magnetic beach effect for slow waves.
A compact multi-wire-layered secondary winding for Tesla transformer
Authors: Zhao Liang , Su Jian-cang , Li Rui , Wu Xiao-long , Xu Xiu-dong , Qiu Xu-dong , Zeng Bo , Cheng Jie , Zhang Yu , Gao Peng-cheng
Published: May 2017

A compact multi-wire-layered (MWL) secondary winding for a Tesla transformer is put forward. The basic principle of this winding is to wind the metal wire on a polymeric base tube in a multi-layer manner. The tube is tapered and has high electrical strength and high mechanical strength. Concentric-circle grooves perpendicular to the axis of the tube are carved on the surface of the tube to wind the wire. The width of the groove is basically equal to the diameter of the wire so that the metal wire can be fixed in the groove without glue. The depth of the groove is n times of the diameter of the wire to realize the n-layer winding manner. All the concentric-circle grooves are connected via a spiral groove on the surface of the tube to let the wire go through. Compared with the traditional one-wire-layered (OWL) secondary winding for the Tesla transformer, the most conspicuous advantage of the MWL secondary winding is that the latter is compact with only a length of 2/n of the OWL. In addition, the MWL winding has the following advantages: high electrical strength since voids are precluded from the surface of the winding, high mechanical strength because polymer is used as the material of the base tube, and reliable fixation in the Tesla transformer as special mechanical connections are designed. A 2000-turn MWL secondary winding is fabricated with a winding layer of 3 and a total length of 1.0 m. Experiments to test the performance of this winding on a Tesla-type pulse generator are conducted. The results show that this winding can boost the voltage to 1 MV at a repetition rate of 50 Hz reliably for a lifetime longer than 104 pulses, which proves the feasibility of the MWL secondary winding.
Descriptors for predicting the lattice constant of body centered cubic crystal
Authors: Takahashi Keisuke , Takahashi Lauren , Baran Jakub D. , Tanaka Yuzuru
Published: May 2017

The prediction of the lattice constant of binary body centered cubic crystals is performed in terms of first principle calculations and machine learning. In particular, 1541 binary body centered cubic crystals are calculated using density functional theory. Results from first principle calculations, corresponding information from periodic table, and mathematically tailored data are stored as a dataset. Data mining reveals seven descriptors which are key to determining the lattice constant where the contribution of descriptors is also discussed and visualized. Support vector regression (SVR) technique is implemented to train the data where the predicted lattice constants have the mean score of 83.6% accuracy via cross-validation and maximum error of 4% when compared to experimentally determined lattice constants. In addition, trained SVR is successful in predicting material combinations from a desired lattice constant. Thus, a set of descriptors for determining the lattice constant is identified and can be used as a base descriptor for lattice constants of further complex crystals. This would allow for the acceleration of the search for lattice constants of desired atomic compositions as well as the prediction of new materials based on a specified lattice constant.
Modeling of the multilevel conduction characteristics and fatigue profile of Ag/La1/3Ca2/3MnO3/Pt structures using a compact memristive approach
Authors: Miranda E. , Román Acevedo W. , Rubi D. , Lüders U. , Granell P. , Suñé J. , Levy P.
Published: May 2017

The hysteretic conduction characteristics and fatigue profile of La1/3Ca2/3MnO3 (LCMO)-based memristive devices were investigated. The oxide films were grown by pulsed laser deposition (PLD) and sandwiched between Ag and Pt electrodes. The devices exhibit bipolar resistive switching (RS) effect with well-defined intermediate conduction states that arise from partial SET and RESET events. The current-voltage curves are modeled and simulated using a compact memristive approach. Two equations are considered: one for the electron transport based on the double-diode equation and the other for the memory state of the device driven by the play operator with logistic ridge functions. An expression that accounts for the remnant resistance of the device is obtained after simplifying the model equations in the low-voltage limit. The role played by the power dissipation in the LCMO reset dynamics as well as the asymmetrical reduction of the resistance window caused by long trains of switching pulses are discussed.
Reaching saturation in patterned source vertical organic field effect transistors
Authors: Greenman Michael , Sheleg Gil , Keum Chang-min , Zucker Jonathan , Lussem Bjorn , Tessler Nir
Published: May 2017

Like most of the vertical transistors, the Patterned Source Vertical Organic Field Effect Transistor (PS-VOFET) does not exhibit saturation in the output characteristics. The importance of achieving a good saturation is demonstrated in a vertical organic light emitting transistor; however, this is critical for any application requiring the transistor to act as a current source. Thereafter, a 2D simulation tool was used to explain the physical mechanisms that prevent saturation as well as to suggest ways to overcome them. We found that by isolating the source facet from the drain-source electric field, the PS-VOFET architecture exhibits saturation. The process used for fabricating such saturation-enhancing structure is then described. The new device demonstrated close to an ideal saturation with only 1% change in the drain-source current over a 10 V change in the drain-source voltage.
Quasi-free-standing graphene nano-islands on Ag(110), grown from solid carbon source
Authors: Wu Rongting , Ren Junhai , Dong Li , Wang Yeliang , Huan Qing , Gao H.-J.
Published: May 2017

Structural, electronic, and mechanical properties of graphene islands grown by depositing carbon atoms directly onto a hot single crystal Ag(110) surface are experimentally investigated. First, graphene nano-islands with morphologies tuned by carbon flux and substrate temperatures are fabricated. Moiré superstructures are found to be superposed on the graphene islands, corresponding to the islands' varied orientations and periodicities with respect to the underlying Ag(110) substrate. Both Scanning tunnelling spectroscopy and Raman spectroscopy indicate a weak interaction between graphene and the substrate, which is further confirmed by scanning tunnelling microscopy tip induced graphene flake movement.
Planar lighting from optimized graphite papers made of graphite oxide
Authors: Tan Ziqi , Xu Huailiang , Zhou Bucun , Qi Zeming , Qu Yan , Zhu Yanwu
Published: May 2017

We report the preparation of large-area graphite papers with thicknesses from 100 μm to more than 1 mm, by the reduction and graphitization of graphite oxide at elevated temperatures. The papers can be produced on a size of 20 × 20 cm2 and have a low mass density. X-ray diffraction and Raman characterization show that the stacking of graphitic layers in the papers follows the Bernal stacking, and X-ray photoelectron spectroscopy indicates a carbon purity of above 98 at. % in the papers. The graphite papers have an electrical conductivity of 2533–4996 S/m and a thermal conductivity of 42–149 W/mK, depending on the thickness. When a power input of above 10 W is applied on the paper with a thickness of 98 μm, incandescence is observed, corresponding to a temperature of higher than 1000 °C, which is increased with the input power.
Liquid marble: A novel liquid nanofoam structure for energy absorption
Authors: Li Mingzhe , Lu Weiyi
Published: May 2017

The liquid nanofoam (LN), a system composed of liquid and hydrophobic nanoporous particles, is a promising energy absorbing material. Despite its excellent energy absorbing capabilities under quasi-static conditions, the LN’s performance is limited under dynamic impacts due to its heterogeneity. We hypothesize that the energy absorption capacity of the LN can be increased by reconfiguration of the material into a liquid marble form. To test this hypothesis, we have prepared the LN sample in two different configurations, one with the heterogeneous layered structure and the other with a macroscopically homogeneous liquid marble structure. The mechanical behavior of these two types of LN was examined by quasi-static compression tests and dynamic impact tests. We demonstrated that although both types of LN exhibited comparable quasi-static energy absorption capacity, the liquid marble form of LN showed better performance under dynamic impacts. These findings suggest that the liquid marble form is the preferred LN structure under blunt impact and shed lights on the design of next-generation energy absorbing materials and structures.
Impact of E × B shear flow on low-n MHD instabilities
Authors: Chen J. G. , Xu X. Q. , Ma C. H. , Xi P. W. , Kong D. F. , Lei Y. A.
Published: May 2017

Recently, the stationary high confinement operations with improved pedestal conditions have been achieved in DIII-D [K. H. Burrell et al., Phys. Plasmas 23, 056103 (2016)], accompanying the spontaneous transition from the coherent edge harmonic oscillation (EHO) to the broadband MHD turbulence state by reducing the neutral beam injection torque to zero. It is highly significant for the burning plasma devices such as ITER. Simulations about the effects of E × B shear flow on the quiescent H-mode (QH-mode) are carried out using the three-field two-fluid model in the field-aligned coordinate under the BOUT++ framework. Using the shifted circular cross-section equilibriums including bootstrap current, the results demonstrate that the E × B shear flow strongly destabilizes low-n peeling modes, which are mainly driven by the gradient of parallel current in peeling-dominant cases and are sensitive to the Er shear. Adopting the much more general shape of E × B shear (ωE=Er/RBθ) profiles, the linear and nonlinear BOUT++ simulations show qualitative consistence with the experiments. The stronger shear flow shifts the most unstable mode to lower-n and narrows the mode spectrum. At the meantime, the nonlinear simulations of the QH-mode indicate that the shear flow in both co- and counter directions of diamagnetic flow has some similar effects. The nonlinear mode interaction is enhanced during the mode amplitude saturation phase. These results reveal that the fundamental physics mechanism of the QH-mode may be shear flow and are significant for understanding the mechanism of EHO and QH-mode.
Wrinkling reduction of membrane structure by trimming edges
Authors: Liu Mingjun , Huang Jin , Liu Mingyue
Published: May 2017

Thin membranes have negligible bending stiffness, compressive stresses inevitably lead to wrinkling. Therefore, it is important to keep the surface of membrane structures flat in order to guarantee high precision. Edge-trimming is an effective method to passively diminish wrinkles, however a key difficulty in this process is the determination of the optimal trimming level. In this paper, regular polygonal membrane structures subjected to equal radial forces were analyzed, and a new stress field distribution model for arc-edge square membrane structure was proposed to predict the optimal trimming level. This model is simple and applicable to any polygonal membrane structures. Comparison among the results of the finite element analysis, and the experimental and analytical results showed that the proposed model accurately described the stress field distribution and guaranteed that there are no wrinkles appear inside the effective inscribed circle region for the optimal trimming level.