bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-temperature atomic layer deposition delivers more active and stable Pt-based catalysts
Authors: Van Bui Hao , Grillo Fabio , Kulkarni Sri Sharath , Bevaart Ronald , Van Thang Nguyen , van der Linden Bart , Moulijn Jacob A. , Makkee Michiel , Kreutzer Michiel T. , van Ommen J. Ruud
Published: July 2017

We tailored the size distribution of Pt nanoparticles on graphene nanoplatelets at a given metal loading by using low-temperature atomic layer deposition.
Electronic properties and potential applications of the heterojunction between silicon and multi‐nanolayer amorphous selenium
Authors: John J.D. , Saito I. , Toyama R. , Ochiai J. , Yamada T. , Masuzawa T. , Chua D.H.C. , Okano K.
Published: July 2017

The electronic properties of the junction formed between multi‐nanolayer amorphous selenium and silicon are studied. The current–voltage (I–V) relationship of this type of junction was characterised and the result showed pn junction rectification. Capacitance–voltage (C–V) measurements were also used to obtain the value of the diffusion potential of the junction. From these data, the ideality factor and built‐in potential were evaluated. The results show potential in the application of amorphous selenium and silicon as materials in tandem photovoltaic cells and in wide spectral range photodetectors.
Spatial coding in sonar imaging
Authors: Wang Jingxi , Guo Xin , Ge Feng‐Xiang , Arce Gonzalo R.
Published: July 2017

A practical deployment is presented for sonar imaging with fewer transmitters and receivers. Spatial coding via transmit beamforming is used for target detection and localisation. Transmit beamforming reduces the ambiguity in a model and improves imaging performance. To reconstruct the resultant underdetermined system of equations, a sparse signal reconstruction framework is used, and the inverse problem is solved by using an iterative optimisation algorithm. Deployment is optimised for better target detection and localisation performance. Successful sonar imaging reconstruction is guaranteed by the restricted isometry property with high probability. A numerical simulation shows that the proposed method can detect and localise targets efficiently, with better imaging results than those attained by conventional methods or the compressive sensing method without spatial coding.
Discrete‐time speed servo system design – a comparative study: proportional–integral versus integral sliding mode control
Authors: Petronijević Milutin , Peruničić‐Draženović Branislava , Milosavljavić Čedomir , Veselić Boban
Published: July 2017

This work presents a comparative study of two approaches for design of high performance discrete‐time velocity servo systems with induction motors (IMs). The first approach uses the conventional proportional–integral controller with one‐step delayed disturbance compensator (OSDC). The OSDC is based on measurements of the control input and plant states. The second approach uses the discrete‐time integral sliding mode (DISM) controller with a first‐order disturbance compensator, which is based on switching function signal measurement only. The controlled plant, consisting of IM in the commonly used indirect field‐oriented control (IFOC) scheme, is approximated by first‐order dynamic model for control design purpose. Comparisons are conducted through simulations considering an ideal case (without unmodelled dynamics) and a regular one, using MATLAB/Simulink models of real IFOC structure elements. The experimental investigation is conducted as well. The performed tests show that both controllers enhanced with the corresponding disturbance compensators are suitable for high‐performance control systems design if speed measurement is near noise‐free case, with better performance from DISM. If Euler backward difference is applied for speed detection, both control systems need some retuning in order to make a compromise between chattering and tracking accuracy.
Improved BM3D denoising method
Authors: Li YingJiang , Zhang Jiangwei , Wang Maoning
Published: July 2017

Block matching 3D denoising (BM3D) is an excellent single‐image denoising method. However, it still needs to be improved for solving practical problems. In this study, the authors attempt to improve the method of BM3D. First, one of the problems of BM3D is that some of its references cannot perform self‐adaption when the noise intensity of the images is changed. Therefore, they propose a method using total variation (TV) to calculate the image noise intensity and make the references perform self‐adaption. Second, finding similar blocks in the BM3D method is a time‐consuming procedure. To solve this problem, they analyse the relationship between the numbers of similar blocks and denoising effect, improve the process of searching for similar blocks, and reduce the running time. Third, through the experiment they find that the denoising effect of BM3D method in the domain of complex texture is unsatisfactory. Thus, they proposed a hybrid denoising method for the complex texture area, using the new TV model and BM3D method together to restore the image. Their experimental results show that the improved BM3D method performs better than the original BM3D method.
Quantitative growth analysis of pulp necrotic tooth (post‐op) using modified region growing active contour model
Authors: Shanmugam Leninisha , Gunasekaran Krithika , Natarajan Aishwarya , Kaliaperumal Vani
Published: July 2017

In the field of dentistry, prospective clinical study reports affirm the need for approximate growth analysis of endodontic tooth post treatment. There is no difference in the frequency, appearance or extent of root resorption in the teeth. It is necessary to elucidate the role of endodontic treatment in the root resorption. Differences between the two samples (radiographs), which are taken with specified period of intervals, in terms of the frequency of growth changes in treated teeth is needed to observe accurately. This study mainly aims at this requirement by utilising slightly modified region‐based growing active contour model for quantitative growth analysis of tooth. Recall radiographs of endodontic regeneration involving immature permanent teeth with pulp necrosis have been considered as input in this research. Image enhancing techniques such as dilation and erosion of mathematical morphology are then performed sequentially to emphasise the outlying pixels. Finally, the criterions which include the root length, apical diameter and the dentinal wall thickness are calibrated and given in experimental results. The visual sample results and along with its measurements proved the efficiency of the proposed algorithm.
Dynamical characteristics of nano‐lasers subject to optical injection and phase conjugate feedback
Authors: Han Hong , Shore K. Alan
Published: July 2017

The dynamics of nano‐lasers has been analysed using rate equations which include the Purcell cavity‐enhanced spontaneous emission factor F and the spontaneous emission coupling factor β. It is shown that when subject to optical injection and phase conjugate feedback, nano‐lasers may exhibit remarkably stable small‐amplitude oscillations with frequencies of order 300 GHz. Critically, it is established that such oscillations persist when the effects of noise are taken into account. The appearance of such high‐frequency oscillations is associated with the effective reduction of the carrier lifetime for larger values of the Purcell factor, F, and spontaneous coupling factor, β. The effects of the feedback distance and bias currents are also considered. As the optical injection strength increases for fixed phase conjugate feedback and relatively short feedback distances, the nano‐laser displays periodic dynamics and then enters stable locking. As the feedback distance increases, the quasi‐periodic dynamics dominates. Increased bias current can also induce quasi‐periodic behaviour albeit this may be ameliorated by reducing the strength of the phase conjugate feedback.
Understanding Site Selectivity in the Palladium-Catalyzed Cross-Coupling of Allenylsilanolates
Authors: Denmark Scott , Ambrosi Andrea
Published: July 2017

Allenylsilanolates can undergo cross-coupling at the α- or γ-terminus, and site selectivity appears to be determined by the intrinsic transmetalation mechanism. Fine-tuning of concentration, nucleophilicity, and steric bulk of the silanolate moiety allows for the selective formation of one isomer over the other. Whereas the α-isomer can be obtained in synthetically useful yield, the γ-isomer is favored only when employing reaction conditions that are inevitably associated with diminished reactivity.
Preterm Preeclampsia and Timing of Delivery: A Systematic Literature Review
Authors: Guida José Paulo de Siqueira , Surita Fernanda Garanhani , Parpinelli Mary Angela , Costa Maria Laura
Published: July 2017

Introduction Preeclampsia, a multifactorial disease with pathophysiology not yet fully understood, is a major cause of maternal and perinatal morbidity and mortality, especially when preterm. The diagnosis is performed when there is an association between arterial hypertension and proteinuria or evidence of severity. There are unanswered questions in the literature considering the timing of delivery once preterm preeclampsia has been diagnosed, given the risk of developing maternal complications versus the risk of adverse perinatal outcomes associated with prematurity. The objective of this systematic review is to determine the best timing of delivery for women diagnosed with preeclampsia before 37 weeks of gestation.

Methods Systematic literature review, performed in the PubMed database, using the terms preeclampsia, parturition and timing of delivery to look for studies conducted between 2014 and 2017. Studies that compared the maternal and perinatal outcomes of women who underwent immediate delivery or delayed delivery, in the absence of evidence of severe preeclampsia, were selected.

Results A total of 629 studies were initially retrieved. After reading the titles, 78 were selected, and their abstracts, evaluated; 16 were then evaluated in full and, in the end, 6 studies (2 randomized clinical trials and 4 observational studies) met the inclusion criteria. The results were presented according to gestational age range (< 34 weeks and between 34 and 37 weeks) and by maternal and perinatal outcomes, according to the timing of delivery, considering immediate delivery or expectant management. Before 34 weeks, the maternal outcomes were similar, but the perinatal outcomes were significantly worse when immediate delivery occurred. Between 34 and 37 weeks, the progression to severe maternal disease was slightly higher among women undergoing expectant management, however, with better perinatal outcomes.

Conclusions When there is no evidence of severe preeclampsia or impaired fetal well-being, especially before 34 weeks, the pregnancy should be carefully surveilled, and the delivery, postponed, aiming at improving the perinatal outcomes. Between 34 and 37 weeks, the decision on the timing of delivery should be shared with the pregnant woman and her family, after providing information regarding the risks of adverse outcomes associated with preeclampsia and prematurity.
Atropine Treatment for Hypertrophic Pyloric Stenosis: A Systematic Review and Meta-Analysis
Authors: Cascini Valentina , Chiesa Pierluigi , Pierro Agostino , Zani Augusto , Lauriti Giuseppe
Published: July 2017

Introduction Several authors have reported the use of atropine as an alternative treatment to pyloromyotomy in infants with hypertrophic pyloric stenosis (HPS). Our aims were to review the efficacy of atropine in treating HPS and to compare atropine therapy versus pyloromyotomy.

Materials and Methods Using a defined search strategy (PubMed, MEDLINE, OVID, Embase, Cochrane databases), two investigators independently identified studies reporting the use of atropine for HPS. Case reports and opinion articles were excluded. Outcome measures included success rate, side effects, and length of hospital stay. Maneuvers were compared using Fisher's exact test, and meta-analysis was conducted using RevMan 5.3. Data are expressed as mean ± standard deviation.

Results Systematic review: of 2,524 abstracts screened, 51 full-text articles were analyzed. There were no prospective or randomized studies. Twelve articles (508 infants) reported HPS resolution using atropine in 402 (79.1%) patients. Atropine side effects were documented in 38/251 (15.1%) infants and included tachycardia, increased transaminases, and flushed skin. Meta-analysis: five studies compared atropine treatment (293 infants) with pyloromyotomy (537 infants). Pyloromyotomy had higher success rate (100%) than atropine (80.8%; p < 0.01) and shorter hospital stay (5.6 ± 2.3 vs. 10.3 ± 3.8 days, respectively; p < 0.0001).

Conclusion Comparative but nonrandomized studies indicate that atropine is less effective than pyloromyotomy to treat infants with HPS. Currently, there is no evidence-based literature to support atropine treatment in these infants. To our knowledge, atropine should be reserved for patients unfit for general anesthesia or surgery.
Modified Intervastus Approach to the Knee
Authors: Kohlman James , Valle Craig , Sartawi Muthana
Published: July 2017

The modified intervastus approach to the anterior knee is an approach that may be used in the majority of patients undergoing total knee arthroplasty. This article presents the first description of this approach. The advantages of this approach include its extensile nature, similar to a medial parapatellar approach, and preservation of the extensor mechanism and the vastus medialis, leading to a more rapid return to active knee extension than is traditionally observed. The approach is also simple to perform, easy to close, and is compatible with more extensile approaches such as a quadriceps snip if required in revision scenarios.
Tolerance Induction of Horse Allergy by Horse Contact with Curly Horses
Authors: Mitlehner W. , Mitlehner H.
Published: July 2017

A horse allergic rider completed 60 riding lessons on Curly Horses within six months. This rider has become clinically tolerant to normal horse breeds within this time. This case may indicate that riding and brushing ABCR Curly Horses after 60 riding hours facilitates tolerance induction. Our data indicate that this could be a valid alternative to the common recommendation to strictly avoid horse riding.
Spacer, Aerosoltherapie durch Raum und Zeit
Authors: Voshaar Thomas , Haidl Peter , Clös Rolf
Published: July 2017

Ziel der Literaturübersicht In diesem Review werden die Ergebnisse einer Literaturanalyse zur Anwendung von Spacern mit Dosieraerosolen beschrieben und bewertet.

Methodik Neben einer umfangreichen Aufarbeitung der Spacereffekte werden die Auswirkungen aktueller Leitlinien und Rahmenbedingungen für Produktzulassungen auf die Spaceranwendung beschrieben, die sich aus der Interaktion der Eigenschaften von Dosieraerosolen mit einem Spacer ergeben.

Ergebnisse Zur Vermeidung von Koordinationsproblemen bei der Auslösung eines Dosieraerosols zu Beginn der Einatmung sind Spacer generell sinnvoll. Für alle Dosieraerosol-Spacer-Kombinationen gilt zudem, dass die Mund-Rachen-Deposition im Vergleich zur Dosieraerosolanwendung ohne Spacer reduziert wird. Einige neuere Dosieraerosole setzen allerdings das Aerosol in einer Qualität frei, die einen Spacer zur Vermeidung einer hohen Wirkstoffdeposition im Mund-Rachen-Raum nicht zwingend erforderlich macht, weil die Aerosolqualität über einen Spacer nicht mehr wesentlich verbessert werden kann. Die aus einem Spacer freigesetzte Wirkstoffmasse und die Aerosolqualität variieren aber erheblich bei Verwendung unterschiedlicher Spacer. Ein Spacerwechsel kann bei Verwendung des gleichen Dosieraerosols maximal zu einer Verdopplung oder Halbierung der applizierten Wirkstoffmenge führen. Diese Fakten werden inzwischen von der europäischen Zulassungsbehörde berücksichtigt.

Schlussfolgerung Die Fachinformationen der Dosieraerosole, die nach 2009 entwickelt und zugelassen wurden, sollten, sofern eine Spaceranwendung vorgesehen ist, mindestens eine konkrete Spacerempfehlung aussprechen, die auf entsprechenden In-vitro-Daten bzw. ergänzenden In-vivo-Daten beruht. Wird ein anderer Spacer als der empfohlene mit diesem Dosieraerosol eingesetzt, ist es nicht möglich, die applizierte Dosis vorherzusehen. Dies sollte bei der Spacerauswahl berücksichtigt werden.
Aktuelle Bedeutung der dermatologischen Röntgentherapie
Authors: Eberlein B.
Published: July 2017

Die dermatologische Röntgentherapie hat mit neuen Geräten wieder eine langfristige Perspektive. Auch deshalb ist es wichtig, diejenigen Indikationen für eine Röntgentherapie im Bereich der Dermatologie und deren Stellenwert im therapeutischen Kanon herauszustellen. Die Therapie kann vom spezialisierten Dermatologen eingesetzt werden bei gutartigen Hauterkrankungen wie Keloiden (v. a. postoperativ), in den frühen Stadien des M. Dupuytren, des M. Ledderhose und der Induratio penis plastica. Bei den Präkanzerosen werden sehr gute Erfolgsraten bei der Lentigo maligna erreicht, wobei die Therapie bei älteren Patienten auch als Primärtherapie eingesetzt werden kann. Eine Strahlentherapie für Basalzellkarzinome, Plattenepithelkarzinome und Lentigo-maligna-Melanome kommt dann infrage, wenn lokal nicht in sano resezierbare Tumoren vorliegen, Patienten inoperabel sind oder eine Einwilligung zur Operation nicht gegeben wird. Sowohl die Mycosis fungoides wie auch das Kaposi-Sarkom sind strahlungssensible Tumoren, bei denen die Radiotherapie primär oder adjuvant zur Lokalkontrolle erfolgreich einsetzbar ist. Aufgrund dieser Einsatzmöglichkeiten werden Kenntnisse im Bereich der dermatologischen Röntgenweichstrahltherapie vermittelt, um Patienten diese erfolgreichen Behandlungen bei entsprechender Indikation anbieten zu können.
Die Dermatologische Klinik am UniversitätsSpital Zürich heute
Authors: French L.
Published: July 2017

Die Dermatologische Klinik des UniversitätsSpitals Zürich fokussiert als eines der renommiertesten universitären Zentren Europas primär darauf, eine fundierte, breite und möglichst innovative Grundversorgung der Patientinnen und Patienten sicherzustellen. Dies basierend auf einer aktiven und sehr zielgerichteten klinischen und Grundlagen-Forschung in den Bereichen schwere entzündliche Hautkrankheiten und Dermatoonkologie unter der Prämisse und langjährigen Tradition der translationalen Forschung. Ziel ist es, mit einem hochprofessionellen Mitarbeiterstab und entsprechender Nachwuchsförderung die führende Position der Klinik und ihre Kompetitivität auf die Zukunft langfristig zu halten und weiter zu entwickeln durch innovativste Forschung und Behandlung/Diagnostik-Methoden in der Patientenversorgung. Der Rolle in der Gesellschaft als führendes Dermatologie-Zentrum wird die Klinik gerecht durch engen Austausch mit den zuweisenden Ärzten – in Sinne der Weitergabe von aktuellstem Knowhow für die Patienten in den Praxen. Durch gezielte Öffentlichkeitsarbeit soll das Bewusstsein der Bevölkerung auf häufige und risikoreiche Hautkrankheiten sensibilisiert und damit das Verständnis für das Fach der Dermatologie gestärkt werden.
The Identification of Araliaceae Species by ITS2 Genetic Barcoding and Pollen Morphology
Authors: Reunov Arkadiy , Reunova Galina , Atopkin Dmitry , Reunova Yulia , Muzarok Tamara , Zakharov Evgeny , Zhuravlev Yury
Published: July 2017

The genetic barcode ITS2 (ITS: internal transcribed spacer) and pollen morphology were used for the identification of the pharmacologically valuable wild Araliaceae species Panax ginseng, Oplopanax elatus, Aralia elata, Aralia continentalis, Eleutherococcus senticosus, and Eleutherococcus sessiliflorus inhabiting the natural forests of Primorye, Russia. The ITS2 locus successfully identified all six species, which supports the use of ITS2 as a standard barcode for medicinal plants. However, the ITS2 locus was insufficient for intra-specific discrimination in these species, neither within Primorye nor from other world representatives within GenBank. Araliaceae pollen was confirmed to undergo size-reducing metamorphosis. The final morphotypes were species-specific for each of the six species but could not discriminate intra-species geographic localities within Primorye. The morphologies of the final pollen morphotypes from homologous species inhabiting other parts of the world are not yet known. Therefore, whether pollen is applicable for Araliaceae intra-species discrimination between Primorye and other world localities could not be established. Based on these findings, we propose that the ITS2 genetic barcode and the final pollen morphotypes are suitable for the identification of Araliaceae species. However, further studies will be needed to determine the suitability of genetic and pollen traits for Araliaceae geographic authentication.
Epidemiology of hepatic encephalopathy in german hospitals – the EpHE study
Authors: Labenz Christian , Wörns Marcus-Alexander , Schattenberg Jörn , Huber Yvonne , Galle Peter , Labenz Joachim ,   ALGK study group
Published: July 2017

Background Hepatic encephalopathy (HE) is a serious complication of liver cirrhosis. The proportion of patients with liver cirrhosis attending German hospitals suffering from HE is unknown.

Methods In the first part of the study, data of 14 community hospitals and 5 university hospitals covering the years 2010 and 2011 were analyzed retrospectively for the DRG codes of liver cirrhosis and hepatic encephalopathy. In the second prospective part of the multicenter observational study, all patients with liver cirrhosis attending the departments of gastroenterology of 16 participating community hospitals within a study period of 3 months were included and screened for HE clinically according to the West Haven criteria (grades 1 – 4).

Results A diagnosis of liver cirrhosis has been coded in 6366 cases in 2010 and in 7279 cases in 2011. In the vast majority of hospitals, less than 20 % of these cases had an additional DRG code for HE. Two hundred seventy-eight patients with liver cirrhosis were included into the prospective study. A clinically detectable HE was present in 36 % of the patients (n = 99). The majority was classified as West Haven 1 (n = 59, 59.6 %). Of the patients without clinical sings of HE, 48 % (n = 134) showed a pathological NCT.

Conclusion Our data suggest that HE is underdiagnosed in German hospitals. Since treatment of HE may improve the prognosis of the patients as well as their quality of life, hospitalized patients with liver cirrhosis should be routinely screened for HE.
Decontamination of Mikania glomerata Leaves by Gamma Irradiation: Coumarin Determination by HPLC-DAD, Microbiological Control and Genotoxicological Studies
Authors: Gouvêa Marcos , Ferreira-Machado Samara , da Silva Thalita , Lima Julien , Lau Cláudio , Esper Luciana , Mourão Samanta , Macedo Elizabeth , Vital Helio , Andrade Edson , Netto Annibal , Marques Flávia , Peregrino Carlos
Published: July 2017

Gamma irradiation as a decontaminating physical agent could be an important tool in the production chain of herbal medicines by improving the microbiological quality of raw materials and the safety of final products. This study was undertaken to investigate the genotoxic potential and eventual chemical modifications of a batch of Mikania glomerata raw material decontaminated by different doses of gamma irradiation (2.0, 3.5, and 5.0 kGy), using a cesium-137 source. DNA damage was assessed in vitro by agarose gel electrophoresis in regard to double-chain breaks of plasmid pUC 9.1 DNA and in vivo by micronucleus test in bone marrow cells of Wistar rats. Cytotoxicity in bone marrows was assessed by scoring polychromatic and normochromatic erythrocytes ratio. An HPLC-DAD method was adapted and validated for the enhancement of coumarin selectivity from the other matrix constituents. The microbial load was satisfactorily reduced, leading to sterilization at the highest dose. Genotoxic and cytotoxic effects were not increased in the in vitro and in vivo models. The concentration of coumarin and the chromatographic profiles of the hydroalcoholic plant extracts (ethanol 70% v/v) were not modified after such process. Therefore, this work suggests that gamma irradiation of M. glomerata raw material is suitable and safe for microbiological control purposes at the employed doses.
Interiors and interiority in Vermeer: empiricism, subjectivity, modernism
Authors: Binstock Benjamin
Published: July 2017

Johannes Vermeer may well be the foremost painter of interiors and interiority in the history of art, yet we have not necessarily understood his achievement in either domain, or their relation within his complex development. This essay explains how Vermeer based his interiors on rooms in his house and used his family members as models, combining empiricism and subjectivity. Vermeer was exceptionally self-conscious and sophisticated about his artistic task, which we are still laboring to understand and articulate. He eschewed anecdotal narratives and presented his models as models in “studio” settings, in paintings about paintings, or art about art, a form of modernism. In contrast to the prevailing conception in scholarship of Dutch Golden Age paintings as providing didactic or moralizing messages for their pre-modern audiences, we glimpse in Vermeer’s paintings an anticipation of our own modern understanding of art. This article is published as part of a collection on interiorities.
Characterization of intrinsic subgap density-of-states in exfoliated MoS2 FETs using a multi-frequency capacitance-conductance technique
Authors: Bae Hagyoul , Kim Choong-Ki , Choi Yang-Kyu
Published: July 2017

A multi-frequency capacitance-conductance technique is proposed for characterizing the intrinsic density-of-states (DOS: gint(E)) inside an energy bandgap range (EV < E < EC) by de-embedding the structure-dependent parameters such as parasitic capacitance and resistance in a fabricated exfoliated molybdenum disulfide (MoS2) field effect transistor (EM-FET). The proposed technique uses the measured frequency-dispersive capacitance (Cm) and conductance (Gm=1/Rm=ωCmDm) data with the measured dissipation factor Dm(=Gm/ωCm) at a frequency range of 0.3 kHz to 10 kHz. To extract gint(E), an equivalent circuit model of the MoS2 FET converted from a two-element model for the parallel-mode (Cm-Dm) measurement was developed with this technique.
Improving proton conduction pathways in di- and triblock copolymer membranes: Branched versus linear side chains
Authors: Dorenbos G.
Published: July 2017

Phase separation within a series of polymer membranes in the presence of water is studied by dissipative particle dynamics. Each polymer contains hydrophobic A beads and hydrophilic C beads. Three parent architectures are constructed from a backbone composed of connected hydrophobic A beads to which short ([C]), long ([A3C]), or symmetrically branched A5[AC][AC] side chains spring off. Three di-block copolymer derivatives are constructed by covalently bonding an A30 block to each parent architecture. Also three tri-blocks with A15 blocks attached to both ends of each parent architecture are modeled. Monte Carlo tracer diffusion calculations through the water containing pores for 1226 morphologies reveal that water diffusion for parent architectures is slowest and diffusion through the di-blocks is fastest. Furthermore, diffusion increases with side chain length and is highest for branched side chains. This is explained by the increase of water pore size with 〈Nbond〉, which is the average number of bonds that A beads are separated from a nearest C bead. Optimization of 〈Nbond〉 within the amphiphilic parent architecture is expected to be essential in improving proton conduction in polymer electrolyte membranes.
An experimental study of OH(A2Σ+) + H2: Electronic quenching, rotational energy transfer, and collisional depolarization
Authors: Brouard M. , Lawlor J. , McCrudden G. , Perkins T. , Seamons S. A. , Stevenson P. , Chadwick H. , Aoiz F. J.
Published: July 2017

Zeeman quantum beat spectroscopy has been used to determine the thermal (300 K) rate constants for electronic quenching, rotational energy transfer, and collisional depolarization of OH(A2Σ+) by H2. Cross sections for both the collisional disorientation and collisional disalignment of the angular momentum in the OH(A2Σ+) radical are reported. The experimental results for OH(A2Σ+) + H2 are compared to previous work on the OH(A2Σ+) + He and Ar systems. Further comparisons are also made to the OH(A2Σ+) + Kr system, which has been shown to display significant non-adiabatic dynamics. The OH(A2Σ+) + H2 experimental data reveal that collisions that survive the electronic quenching process are highly depolarizing, reflecting the deep potential energy wells that exist on the excited electronic state surface.
Diffusion and interactions of point defects in hard-sphere crystals
Authors: van der Meer Berend , Dijkstra Marjolein , Filion Laura
Published: July 2017

Using computer simulations, we study the diffusion, interactions, and strain fields of point defects in a face-centered-cubic crystal of hard spheres. We show that the vacancy diffusion decreases rapidly as the density is increased, while the interstitial diffusion exhibits a much weaker density-dependence. Additionally, we predict the free-energy barriers associated with vacancy hopping and find that the increasing height of the free-energy barrier is solely responsible for the slowing down of vacancy diffusion. Moreover, we find that the shape of the barriers is independent of the density. The interactions between vacancies are shown to be weakly attractive and short-ranged, while the interactions between interstitials are found to be strongly attractive and are felt over long distances. As such, we find that vacancies do not form vacancy clusters, while interstitials do form long-lived interstitial clusters. Considering the strain field of vacancies and interstitials, we argue that vacancies will hardly feel each other, as they do not substantially perturb the crystal, and as such exhibit weak interactions. Two interstitials, on the other hand, interact with each other over long distances and start to interact (attractively) when their strain fields start to overlap.
Repetition and pair-interaction of string-like hopping motions in glassy polymers
Authors: Lam Chi-Hang
Published: July 2017

The dynamics of many glassy systems are known to exhibit string-like hopping motions each consisting of a line of particles displacing one another. By using the molecular dynamics simulations of glassy polymers, we show that these motions become highly repetitive back-and-forth motions as temperature decreases and do not necessarily contribute to net displacements. Particle hops which constitute string-like motions are reversed with a high probability, reaching 73% and beyond at low temperature. The structural relaxation rate is then dictated not by a simple particle hopping rate but instead by the rate at which particles break away from hopping repetitions. We propose that disruption of string repetitions and hence also structural relaxations are brought about by pair-interactions between strings.
Stiffness-guided motion of a droplet on a solid substrate
Authors: Theodorakis Panagiotis E. , Egorov Sergei A. , Milchev Andrey
Published: July 2017

A range of technologies require the directed motion of nanoscale droplets on solid substrates. A way of realizing this effect is durotaxis, whereby a stiffness gradient of a substrate can induce directional motion without requiring an energy source. Here, we report on the results of extensive molecular dynamics investigations of droplets on a surface with varying stiffness. We find that durotaxis is enhanced by increasing the stiffness gradient and, also, by increased wettability of the substrate, in particular, when the droplet size decreases. We anticipate that our study will provide further insights into the mechanisms of nanoscale directional motion.
Investigation of intrinsic toroidal rotation scaling in KSTAR
Authors: Yoo J. W. , Lee S. G. , Ko S. H. , Seol J. , Lee H. H. , Kim J. H.
Published: July 2017

The behaviors of an intrinsic toroidal rotation without any external momentum sources are investigated in KSTAR. In these experiments, pure ohmic discharges with a wide range of plasma parameters are carefully selected and analyzed to speculate an unrevealed origin of toroidal rotation excluding any unnecessary heating sources, magnetic perturbations, and strong magneto-hydrodynamic activities. The measured core toroidal rotation in KSTAR is mostly in the counter-current direction and its magnitude strongly depends on the ion temperature divided by plasma current (Ti/IP). Especially the core toroidal rotation in the steady-state is well fitted by Ti/IP scaling with a slope of ∼−23, and the possible explanation of the scaling is compared with various candidates. As a result, the calculated offset rotation could not explain the measured core toroidal rotation since KSTAR has an extremely low intrinsic error field. For the stability conditions for ion and electron turbulences, it is hard to determine a dominant turbulence mode in this study. In addition, the intrinsic toroidal rotation level in ITER is estimated based on the KSTAR scaling since the intrinsic rotation plays an important role in stabilizing resistive wall modes for future reference.
Enhanced radiation tolerance in Mn-doped ferroelectric thin films
Authors: Brewer S. J. , Williams S. C. , Griffin L. A. , Cress C. D. , Rivas M. , Rudy R. Q. , Polcawich R. G. , Glaser E. R. , Bassiri-Gharb N.
Published: July 2017

This work investigates the role of Mn-doping of ferroelectric lead zirconate titanate (PZT) thin films exposed to a range of ionizing radiation doses. PZT thin films were fabricated with both undoped and 4% Mn-doped compositions, and the functional response was compared both before and after exposure to gamma radiation doses up to 10 Mrad. A phenomenological model was applied to quantify defect interactions and compare trends in the degradation of the functional response. Mn-doped PZT samples demonstrate reduced magnitude of functional response in non-irradiated samples but exhibit vastly superior radiation tolerance of dielectric and ferroelectric properties across the range of gamma doses studied here. Strong MnZr/Ti″−VO·· defect dipoles pin domain walls, resulting in a lower initial functional response and mitigating the deleterious effects of irradiation on extrinsic contributions to the said response. Piezoelectric response trends as a function of radiation dose are highly nonlinear. The results of this work can be leveraged to engineer next-generation radiation-tolerant ferroelectric materials for applications where high levels of functional response stability are required, especially at elevated ionizing radiation dose.
The chirality-dependent fracture properties of single-layer graphene sheets: Molecular dynamics simulations and finite element method
Authors: Jiang Zonghuiyi , Lin Rong , Yu Peishi , Liu Yu , Wei Ning , Zhao Junhua
Published: July 2017

The chirality-dependent mixed-mode I-II fracture toughness and crack growth angles of single-layer graphene sheets are determined using molecular dynamics (MD) simulations and the finite element (FE) method based on the boundary layer model, respectively. The carbon–carbon bond in the FE method is equivalent to a nonlinear Timoshenko beam based on the Tersoff–Brenner potential. All the results of the present FE method agree well with those of our MD simulations performed using the REBO potential. The chiral crack angles of α = 0° (zigzag), 15°, 30° (or 90°, armchair), and 45° at different loading angles from 0° ≤ φ ≤ 90° (φ = 90° for mode I and φ = 0° for mode II) are studied. The present results show that both critical stress intensity factors (SIFs) and crack growth angles strongly depend on the chiral angle α, the dimensions [in two-dimensional (2D) or three-dimensional (3D) states], as well as the temperature, for a given loading angle φ. The critical equivalent SIFs change from 2.52 to 4.07 nN Å−3/2 in the 2D state and from 2.46 to 5.06 nN Å−3/2 in the 3D state at different loading angles. The SIFs are around one order of magnitude smaller than those of ordinary steel, which indicates that chiral graphene is remarkably brittle in contrast to its ultrahigh strength. These findings should be of great help in understanding the chirality-dependent fracture properties of graphene sheets and designing graphene-based nanodevices.
Phosphorescent Cationic Iridium(III) Complexes with 1,3,4-Oxadiazole Cyclometalating Ligands: Solvent-Dependent Excited-State Dynamics
Authors: Kuang Zhuoran , Wang Xian , Wang Zhen , He Guiying , Guo Qianjin , He Lei , Xia Andong
Published: July 2017

To elucidate the nature of low-lying triplet states and the effect of ligand modifications on the excited-state properties of functional cationic iridium complexes, the solvent-dependent excited-state dynamics of two phosphorescent cationic iridium(III) complexes, namely [Ir(dph-oxd)2(bpy)]PF6 (1) and [Ir(dph-oxd)2(pzpy)]PF6 (2), were investigated by femtosecond and nanosecond transient absorption spectroscopy. Upon photoexcitation to the metal-to-ligand charge-transfer (MLCT) states, the excited-state dynamics shows a rapid process (τ=0.7−3 ps) for the formation of solvent stabilized 3MLCT states, which significantly depends on the solvent polarity for both 1 and 2. Sequentially, a relatively slow process assigned to the vibrational cooling/geometrical relaxation and a long-lived phosphorescent emissive state is identified. Due to the different excited-state electronic structures regulated by ancillary ligands, the solvation-induced stabilization of the 3MLCT state in 1 is faster than that in 2. The present results provide a better sight of excited-state relaxation dynamics of ligand-related iridium(III) complexes and solvation effects on triplet manifolds.
Two Step Chemical Vapor Deposition of In2Se3/MoSe2 van der Waals Heterostructures
Authors: Chen Yu-lin , Li Ming-ling , Wu Yi-ming , Li Si-jia , Lin Yue , Du Dong-xue , Ding Huai-yi , Pan Nan , Wang Xiao-ping
Published: July 2017

Two-dimensional transition metal dichalcogenides heterostructures have stimulated wide interest not only for the fundamental research, but also for the application of next generation electronic and optoelectronic devices. Herein, we report a successful two-step chemical vapor deposition strategy to construct vertically stacked van der Waals epitaxial In2Se3/MoSe2 heterostructures. Transmission electron microscopy characterization reveals clearly that the In2Se3 has well-aligned lattice orientation with the substrate of monolayer MoSe2. Due to the interaction between the In2Se3 and MoSe2 layers, the heterostructure shows the quenching and red-shift of photoluminescence. Moreover, the current rectification behavior and photovoltaic effect can be observed from the heterostructure, which is attributed to the unique band structure alignment of the heterostructure, and is further confirmed by Kevin probe force microscopy measurement. The synthesis approach via van der Waals epitaxy in this work can expand the way to fabricate a variety of two-dimensional heterostructures for potential applications in electronic and optoelectronic devices.
Liana and bamboo cover threaten shrub populations in Atlantic forest fragments
Authors: Carneiro Magda Silva , Campos Caroline Cambraia Furtado , Ramos Flavio Nunes
Published: July 2017

Abiotic and biotic changes caused by forest fragmentation have led to the decline of many plant species. We sought to investigate how biotic (liana and bamboo cover) and abiotic (soil moisture, litter depth, and canopy openness) factors affect the total abundance and the numbers of individuals of Psychotria vellosiana Benth. at each stage of its life cycle (seedlings, juvenile I and II, adult reproductive and vegetative) in a fragmented landscape. P. vellosiana was selected because it is a forest species, important for fauna, especially ants and birds in the understory, and is highly abundant in semideciduous Atlantic forest areas. We hypothesised that fragments with less humidity, greater litter depth, greater canopy openness, and more liana and bamboo cover would contain fewer individuals at all five life cycle stages of that species. Ten 0.01 ha plots were set up in semideciduous Atlantic Forest fragments, and all individuals of P. vellosiana were tagged and measured. The study also measured canopy openness, soil moisture, litter depth, and bamboo and liana cover. Our results indicated that there was a negative relationship between liana and bamboo cover at all stages of the life cycle of P. vellosiana. This is one of the few studies that has investigated environmental effects on all stages of the life cycle of a plant population, and demonstrates that liana and bamboo cover can affect all stages of plant growth and development. Despite some restrictions, we can affirm that forest species are threatened by fragmentation processes, and that the main threat to local populations of P. vellosiana is liana and bamboo cover.
Monomeric and fibrillar α-synuclein exert opposite effects on the catalytic cycle that promotes the proliferation of Aβ42 aggregates
Authors: Chia Sean , Flagmeier Patrick , Habchi Johnny , Lattanzi Veronica , Linse Sara , Dobson Christopher M. , Knowles Tuomas P. J. , Vendruscolo Michele
Published: July 2017

Significance

A variety of neurodegenerative disorders, such as Alzheimer’s and Parkinson’s diseases, involve the aggregation of Aβ and α-synuclein. These two proteins can influence each other in a complex manner, which has so far prevented firm conclusions to be established about whether, in particular, α-synuclein promotes or inhibits Aβ aggregation. By exploiting a highly quantitative chemical kinetics approach, we show that α-synuclein monomers inhibit Aβ42 aggregation by binding to Aβ42 fibrils, thereby preventing them from catalysing the nucleation of further Aβ42 aggregates. By contrast, α-synuclein fibrils do just the opposite, as they catalyse the nucleation of Aβ42 aggregates. These results show how approaches based on chemical kinetics can provide essential insights into complex aggregation phenomena and illustrate the nature of the interaction between Aβ and α-synuclein.
G9a coordinates with the RPA complex to promote DNA damage repair and cell survival
Authors: Yang Qiaoyan , Zhu Qian , Lu Xiaopeng , Du Yipeng , Cao Linlin , Shen Changchun , Hou Tianyun , Li Meiting , Li Zhiming , Liu Chaohua , Wu Di , Xu Xingzhi , Wang Lina , Wang Haiying , Zhao Ying , Yang Yang , Zhu Wei-Guo
Published: July 2017

Significance

The G9a histone methyltransferase primarily regulates the expression of genes associated with cancer development in cancer cells, but it has also been implicated in mediating the DNA damage response. Here, we confirmed a role for G9a in DNA damage repair following double-strand breaks. G9a is recruited to chromatin as a result of casein kinase 2-mediated phosphorylation, where it directly interacts with replication protein A (RPA). G9a binding to RPA modulates RPA and Rad51 foci formation and permits efficient homologous recombination. This molecular mechanism renders cancer cells more resistant to radiation and chemotherapeutics. Our improved understanding of the molecular function of G9a may help with the future design of G9a inhibitors and G9a-based DNA damage agents as cancer therapeutics.
NLR network mediates immunity to diverse plant pathogens
Authors: Wu Chih-Hang , Abd-El-Haliem Ahmed , Bozkurt Tolga O. , Belhaj Khaoula , Terauchi Ryohei , Vossen Jack H. , Kamoun Sophien
Published: July 2017

Significance

Plant and animal nucleotide-binding domain and leucine-rich repeat-containing (NLR) proteins often function in pairs to mediate innate immunity to pathogens. However, the degree to which NLR proteins form signaling networks beyond genetically linked pairs is poorly understood. In this study, we discovered that a large NLR immune signaling network with a complex genetic architecture confers immunity to oomycetes, bacteria, viruses, nematodes, and insects. The network emerged over 100 Mya from a linked NLR pair that diversified into up to one-half of the NLRs of asterid plants. We propose that this NLR network increases robustness of immune signaling to counteract rapidly evolving plant pathogens.
Haploid selection within a single ejaculate increases offspring fitness
Authors: Alavioon Ghazal , Hotzy Cosima , Nakhro Khriezhanuo , Rudolf Sandra , Scofield Douglas G. , Zajitschek Susanne , Maklakov Alexei A. , Immler Simone
Published: July 2017

Significance

Diploid organisms produce haploid gametes for sexual reproduction, resulting in a biphasic life cycle. Although selection during the diploid phase is well understood, selection during the haploid gametic stage and its consequences are largely ignored despite its potential importance for fundamental evolutionary processes, including the rate of adaptation and inbreeding depression, as well as for applied research into fertilization technology. A current dogma assumes that in animals selection on the haploid gametic genotype is minimal. We examined the importance of haploid selection in the zebrafish and found strong fitness consequences of selection on sperm phenotype in the resulting offspring. Genomic data support the idea that these effects may well be the consequence of selection on the haploid sperm genotype.
Conventionalisation and discrimination as competing pressures on continuous speech-like signals
Authors: Little Hannah , Eryilmaz Kerem , de Boer Bart
Published: July 2017

Arbitrary communication systems can emerge from iconic beginnings through processes of conventionalisation via interaction. Here, we explore whether this process of conventionalisation occurs with continuous, auditory signals. We conducted an artificial signalling experiment. Participants either created signals for themselves, or for a partner in a communication game. We found no evidence that the speech-like signals in our experiment became less iconic or simpler through interaction. We hypothesise that the reason for our results is that when it is difficult to be iconic initially because of the constraints of the modality, then iconicity needs to emerge to enable grounding before conventionalisation can occur. Further, pressures for discrimination, caused by the expanding meaning space in our study, may cause more complexity to emerge, again as a result of the restrictive signalling modality. Our findings have possible implications for the processes of conventionalisation possible in signed and spoken languages, as the spoken modality is more restrictive than the manual modality.
Renegotiating the empire, forging the nation (-state): the Bohemian/Czechoslovakian case through the political–economic thought of Thomas G. Masaryk and Karel Kramář, c. 1890–1920s
Authors: Brisku Adrian
Published: July 2017

This article explores the dilemma of the small Bohemian Lands/Czechoslovak nation (-state) in staying “in” or “out” of the larger Habsburg supranational entity in the late nineteenth and the early twentieth century. It does so mainly through the language of political economy (on national wealth creation and redistribution) articulated in the opinions and political actions of Czechoslovakia's two founding statesmen, the first president, Thomas G. Masaryk, and the first prime minister, Karel Kramař. The article argues that their choice of staying “in” the large imperial space was premised upon renegotiating a better political and political–economic deal for the Bohemian Lands, whereas the option of abandoning it and of forging the Czechoslovak nation-state was essentially based on political reasons. And while both advocated an interventionist role for the state in the economy during the imperial period, they considered such a prerogative even more essential for their new nation-state.