bluuebunny/crossref_metadata_2025 huggingface dataset:
Correction: Systematic investigation of the SERS efficiency and SERS hotspots in gas-phase deposited Ag nanoparticle assemblies
Authors: He L. B. , Wang Y. L. , Xie X. , Han M. , Song F. Q. , Wang B. J. , Cheng W. L. , Xu H. X. , Sun L. T.
Published: June 2017

Correction for ‘Systematic investigation of the SERS efficiency and SERS hotspots in gas-phase deposited Ag nanoparticle assemblies’ by L. B. He et al., Phys. Chem. Chem. Phys., 2017, 19, 5091–5101.
Facile synthesis and enhanced electrochemical properties of reduced graphene oxide/MoS2/polyaniline ternary composites
Authors: Yu Ling , Wang Qianqian , Yang Hui , Zhang Qilong , Luo Zhongkuan
Published: June 2017

Ternary composites of reduced graphene oxide/molybdenum disulfide/polyaniline with superior electrochemical performances were prepared via a two-stage facile synthesis.
Urchin-like NiCo2O4 nanoneedles grown on mesocarbon microbeads with synergistic electrochemical properties as electrodes for symmetric supercapacitors
Authors: Zhang Yu , Zhang Yihe , Zhang Deyang , Sun Li
Published: June 2017

Urchin-like NiCo2O4@MCMB nanocomposites were fabricated as electrodes for symmetric supercapacitors, which demonstrated outstanding pseudocapacitive characteristics.
Fast and cost-effective cyclotron production of61Cu using anatZn liquid target: an opportunity for radiopharmaceutical production and R&D
Authors: do Carmo S. J. C. , Alves V. H. P. , Alves F. , Abrunhosa A. J.
Published: June 2017

Following our previous work on the production of radiometals, such as64Cu and68Ga, through the irradiation of liquid targets using a medical cyclotron, we describe in this paper a technique to produce61Cu through the irradiation of natural zinc using a liquid target.
Novel red-emitting phosphors A2HfF6:Mn4+(A = Rb+, Cs+) for solid-state lighting
Authors: Yang Zhaofeng , Wei Qianwen , Rong Meizhu , Yang Zhiyu , Wang Zhengliang , Zhou Qiang , Wang Qin
Published: June 2017

New red-emitting phosphors A2HfF6(A = Rb+, Cs+) doped with Mn4+located at the center of a regular octahedron show intense red emission under blue light excitation and find potential application in LED chips.
β-Pyridylenolate zinc catalysts for the ring-opening homo- and copolymerization of ε-caprolactone and lactides
Authors: Bai Jianliang , Xiao Xia , Zhang Yue , Chao Jianbin , Chen Xia
Published: June 2017

Eleven zinc β-quinolylenolates with varying substituents have been synthesized, and some of these complexes are excellent catalysts for the ring-opening homo- and copolymerization of ε-CL and LAs.
Synthesis, spectroscopic, electrochemical and computational studies of rhenium(i) tricarbonyl complexes based on bidentate-coordinated 2,6-di(thiazol-2-yl)pyridine derivatives
Authors: Klemens Tomasz , Czerwińska Katarzyna , Szlapa-Kula Agata , Kula Slawomir , Świtlicka Anna , Kotowicz Sonia , Siwy Mariola , Bednarczyk Katarzyna , Krompiec Stanisław , Smolarek Karolina , Maćkowski Sebastian , Danikiewicz Witold , Schab-Balcerzak Ewa , Machura Barbara
Published: June 2017

The impact of structure modification of the 2,6-di(thiazol-2-yl)pyridine based ligand was investigated.
Lantern-shaped 3d–4f high-nuclearity clusters with magnetocaloric effect
Authors: Lin Qingfang , Li Jing , Dong Yayu , Zhou Guangpeng , Song You , Xu Yan
Published: June 2017

Two lantern-shaped, high-nuclearity 3d–4f clusters were synthesized by using iminodiacetic acid (IDA) and isonicotinic acid (HIN) as the co-ligand under solvothermal conditions. Magnetic studies show a large magnetocaloric effect (MCE) for the gadolinium analogue.
In vitro and in vivo trackable titanocene-based complexes using optical imaging or SPECT
Authors: Florès Océane , Trommenschlager Audrey , Amor Souheila , Marques Fernanda , Silva Francisco , Gano Lurdes , Denat Franck , Cabral Campello Maria Paula , Goze Christine , Bodio Ewen , Le Gendre Pierre
Published: June 2017

Two unprecedented titanocene-based theranostics have been synthesized, characterized, and tracked either in vitro (BODIPY probe) or in vivo (111In-DOTA probe).
Thorium complexes possessing expanded ring N-heterocyclic iminato ligands: synthesis and applications
Authors: Ghatak Tapas , Drucker Shani , Fridman Natalia , Eisen Moris S.
Published: June 2017

Novel thorium complexes containing six- and seven-membered rings iminato moieties are disclosed. The complexes are highly active for the Tishchenko and cross-Tishchenko reaction.
Investigation of self-ignition characteristics of the microwave plasma torch
Authors: Zhu Dan , Jin Wei , Yu Bingwen , Ying Yangwei , Yu Haixiang , Shan Jin , Yan Yuwei , Jin Qinhan
Published: June 2017

Photos of the dynamic self-ignition process of the plasma with 0.1 ms exposure time.
The catalytic efficiency of Fe–porphyrins supported on multi-walled carbon nanotubes in the oxidation of olefins and sulfides with molecular oxygen
Authors: Rayati Saeed , Nejabat Fatemeh
Published: June 2017

A Fe–porphyrin catalyst was anchored covalently onto functionalized multi-walled carbon nanotubes.
CuO@Fe2O3 catalyzed C1-alkynylation of tetrahydroisoquinolines (THIQs) via A3 coupling and its decarboxylative strategies
Authors: Gulati Upasana , Rawat Srishti , Rajesh U. Chinna , Rawat Diwan S.
Published: June 2017

C1-alkynylation of tetrahydroisoquinoline (THIQ) with wide substrate scope was achieved via A3 coupling strategy from the reaction among THIQ, aldehydes and alkynes using CuO@Fe2O3 as a nanocatalyst under green reaction conditions.
Enhancing a long-range salt bridge with intermediate aromatic and nonpolar amino acids
Authors: Smith Mason S. , Billings Wendy M. , Whitby Frank G. , Miller McKenzie B. , Price Joshua L.
Published: June 2017

Nonpolar residues enhance a long-range salt-bridge interaction in an α-helix.
Photovoltaic performances of type-II dye-sensitized solar cells based on catechol dye sensitizers: retardation of back-electron transfer by PET (photo-induced electron transfer)
Authors: Ooyama Yousuke , Yamaji Kosuke , Ohshita Joji
Published: June 2017

Catechol dyes (CAT-PET) possessing PET (photo-induced electron transfer) characteristics, which make it possible to retard the back-electron transfer rate, are an efficient dye sensitizer for type-II DSSCs.
Palladium-catalyzed site-selective direct olefination of 6-electron-withdrawing group substituted 3-arylbenzo[d]isoxazoles
Authors: Guo Ying , Shao Ling-Yan , Yu Kun-Kun , Hu Ya-Hua , Liu Hong-Wei , Liao Dao-Hua , Ji Ya-Fei
Published: June 2017

Palladium-catalyzed direct olefination of 6-electron-withdrawing group substituted 3-arylbenzo[d]isoxazoles has been developed with exclusive site-selectivity and excellent E-stereoselectivity.
Perceptually Salient Sound Distortions and Apraxia of Speech: A Performance Continuum
Authors: Haley Katarina L. , Jacks Adam , Richardson Jessica D. , Wambaugh Julie L.
Published: June 2017

Purpose

We sought to characterize articulatory distortions in apraxia of speech and aphasia with phonemic paraphasia and to evaluate the diagnostic validity of error frequency of distortion and distorted substitution in differentiating between these disorders.

Method

Study participants were 66 people with speech sound production difficulties after left-hemisphere stroke or trauma. They were divided into 2 groups on the basis of word syllable duration, which served as an external criterion for speaking rate in multisyllabic words and an index of likely speech diagnosis. Narrow phonetic transcriptions were completed for audio-recorded clinical motor speech evaluations, using 29 diacritic marks.

Results

Partial voicing and altered vowel tongue placement were common in both groups, and changes in consonant manner and place were also observed. The group with longer word syllable duration produced significantly more distortion and distorted-substitution errors than did the group with shorter word syllable duration, but variations were distributed on a performance continuum that overlapped substantially between groups.

Conclusions

Segment distortions in focal left-hemisphere lesions can be captured with a customized set of diacritic marks. Frequencies of distortions and distorted substitutions are valid diagnostic criteria for apraxia of speech, but further development of quantitative criteria and dynamic performance profiles is necessary for clinical utility.
Range and Precision of Formant Movement in Pediatric Dysarthria
Authors: Allison Kristen M. , Annear Lucas , Policicchio Marisa , Hustad Katherine C.
Published: June 2017

Purpose

This study aimed to improve understanding of speech characteristics associated with dysarthria in children with cerebral palsy by analyzing segmental and global formant measures in single-word and sentence contexts.

Method

Ten 5-year-old children with cerebral palsy and dysarthria and 10 age-matched, typically developing children participated in this study. Vowel space area and second formant interquartile range were measured from children's elicited productions of single words and sentences.

Results

Results showed that the children with dysarthria had significantly smaller vowel space areas than typically developing children in both word and sentence contexts; however, overall ranges of second formant movement did not differ between groups in word or sentence contexts. Additional analysis of single words revealed that, compared to typical children, children with dysarthria had smaller second formant interquartile ranges in single words with phonetic contexts requiring large changes in vocal tract configuration, but not in single words with monophthongs.

Conclusions

Results of this study suggest that children with dysarthria may not have globally reduced ranges of articulatory movement compared to typically developing peers; however, they do exhibit reduced precision in producing phonetic targets.
Kinematic Analysis of Speech Sound Sequencing Errors Induced by Delayed Auditory Feedback
Authors: Cler Gabriel J. , Lee Jackson C. , Mittelman Talia , Stepp Cara E. , Bohland Jason W.
Published: June 2017

Purpose

Delayed auditory feedback (DAF) causes speakers to become disfluent and make phonological errors. Methods for assessing the kinematics of speech errors are lacking, with most DAF studies relying on auditory perceptual analyses, which may be problematic, as errors judged to be categorical may actually represent blends of sounds or articulatory errors.

Method

Eight typical speakers produced nonsense syllable sequences under normal and DAF (200 ms). Lip and tongue kinematics were captured with electromagnetic articulography. Time-locked acoustic recordings were transcribed, and the kinematics of utterances with and without perceived errors were analyzed with existing and novel quantitative methods.

Results

New multivariate measures showed that for 5 participants, kinematic variability for productions perceived to be error free was significantly increased under delay; these results were validated by using the spatiotemporal index measure. Analysis of error trials revealed both typical productions of a nontarget syllable and productions with articulatory kinematics that incorporated aspects of both the target and the perceived utterance.

Conclusions

This study is among the first to characterize articulatory changes under DAF and provides evidence for different classes of speech errors, which may not be perceptually salient. New methods were developed that may aid visualization and analysis of large kinematic data sets.

Supplemental Material

https://doi.org/10.23641/asha.5103067
Effects of Blocked and Random Practice Schedule on Outcomes of Sound Production Treatment for Acquired Apraxia of Speech: Results of a Group Investigation
Authors: Wambaugh Julie L. , Nessler Christina , Wright Sandra , Mauszycki Shannon C. , DeLong Catharine , Berggren Kiera , Bailey Dallin J.
Published: June 2017

Purpose

The purpose of this investigation was to compare the effects of schedule of practice (i.e., blocked vs. random) on outcomes of Sound Production Treatment (SPT; Wambaugh, Kalinyak-Fliszar, West, & Doyle, 1998) for speakers with chronic acquired apraxia of speech and aphasia.

Method

A combination of group and single-case experimental designs was used. Twenty participants each received SPT administered with randomized stimuli presentation (SPT-R) and SPT applied with blocked stimuli presentation (SPT-B). Treatment effects were examined with respect to accuracy of articulation as measured in treated and untreated experimental words produced during probes.

Results

All participants demonstrated improved articulation of treated items with both practice schedules. Effect sizes were calculated to estimate magnitude of change for treated and untreated items by treatment condition. No significant differences were found for SPT-R and SPT-B relative to effect size. Percent change over the highest baseline performance was also calculated to provide a clinically relevant indication of improvement. Change scores associated with SPT-R were significantly higher than those for SPT-B for treated items but not untreated items.

Conclusion

SPT can result in improved articulation regardless of schedule of practice. However, SPT-R may result in greater gains for treated items.

Supplemental Materials

https://doi.org/10.23641/asha.5116831
Versatility of Free Cutaneous Flaps for Upper Extremity Soft Tissue Reconstruction
Authors: Wang Howard , Alonso-Escalante Jose , Cho Brian , DeJesus Ramon
Published: June 2017

The goals of upper extremity soft tissue reconstruction should go well beyond providing coverage and restoring function. As the field of reconstructive microsurgery has evolved, free cutaneous flaps (FCFs) are gaining wider application. The advantages of FCF include minimizing donor-site morbidity by preserving the muscle and fascia, improving versatility of flap design, and superior aesthetic results. This review highlights the application of anterolateral thigh, superficial circumflex iliac artery, deep inferior epigastric perforator, superficial inferior epigastric artery, and flow-through flaps for reconstruction of upper extremity defects. These flaps share several qualities in common: well-concealed donor sites, preservation of major arteries responsible of providing inflow to distal extremity, and potential for a two-team approach (donor and recipient sites). While the choice of flaps should be decided based on individual patient and defect characteristics, FCF should be considered as excellent options to achieve the goals of upper extremity reconstruction.
Phobische Angst
Authors: Müller H.V.
Published: June 2017

Schlußfolgerung: Die Anthropophobie des jungen Mediziners gehört wie alle Phobien zu der Crux medicorum. Um so erfreulicher ist es, daß die Homöopathie in diesem wie in ähnlichen Fällen dem Patienten vermitteln kann, sich mit seiner Krankheit auseinanderzusetzen.
A model combustor for studying a reacting jet in an oscillating crossflow
Authors: Fugger Christopher A. , Gejji Rohan M. , Portillo J. Enrique , Yu Yen , Lucht Robert P. , Anderson William E.
Published: June 2017

This paper discusses a novel model combustion experiment that was built for studying the structure and dynamics of a reacting jet in an unsteady crossflow. A natural-gas-fired dump combustor is used to generate and sustain an acoustically oscillating vitiated flow that serves as the crossflow for transverse jet injection. Unlike most other techniques that are limited in operating pressure or acoustic amplitude, this method of generating an unsteady flow field is demonstrated at a pressure of 10 atm with peak-to-peak oscillation amplitudes approaching 20% of the mean pressure. An optically accessible test section designed for these conditions provides access for advanced laser and optical diagnostic measurements. Detailed measurements provide insight into the complex acoustic-hydrodynamic-combustion coupling processes and offer high-quality, high-resolution validation data for numerical simulations. Careful instrumentation port design considerations for the higher amplitude acoustics are detailed. As a whole, this paper focuses on select representative segments of the experiment operational space that highlight our strategy of providing an oscillatory flowfield. This includes presenting the acoustic operational space such as acoustic amplitudes, frequencies, and mode shapes. Select imaging results are then reported to support our strategies capability to produce high-fidelity measurements.
Note: Fabrication of roughened tips for liquid metal ion sources
Authors: Guo Dengshuai , Kang Xiaoming , Hu Jing , Liu Xinyu , He Weiguo
Published: June 2017

In a liquid metal ion source (LMIS), the radius and the surface texture of the LMIS needle tip are demonstrated to have great effect on the I-V characteristics and the threshold voltages. In this paper, the dependence of the AC electrochemical etching parameters on the radius and the surface texture of the needle tip is investigated experimentally. A new method for fabricating the needle tip with the designed radius and texture for the LMIS is proposed. In this method, the roughening of a needle tip consists of two processes: a short time high AC voltage etching process and a long time low AC voltage etching process. The performances of the presented method are validated by a number of experiments.
Vibration and vibration-torsion levels of the S1 state of para-fluorotoluene in the 580–830 cm−1 range: Interactions and coincidences
Authors: Tuttle William D. , Gardner Adrian M. , Whalley Laura E. , Wright Timothy G.
Published: June 2017

A study of the vibration and vibration-torsion levels of para-fluorotoluene in the 580–830 cm−1 region is presented, where a number of features are located whose identity is complicated by interactions and overlap. We examine this region with a view to ascertaining the assignments of the bands; in particular, identifying those that arise from interactions involving various zero-order states (ZOSs) involving both vibrations and torsions. Resonance-enhanced multiphoton ionization (REMPI) is employed to identify the wavenumbers of the relevant transitions, and subsequently zero-kinetic-energy (ZEKE) spectra are recorded to assign the various eigenstates. In some cases, a set of ZEKE spectra are recorded across the wavenumber range of a REMPI feature, and we construct what we term a two-dimensional ZEKE (2D-ZEKE) spectrum, which allows the changing ZOS contributions to the eigenstates to be ascertained. Assignment of the observed bands is aided by quantum chemical calculations and all b1 and a2 symmetry vibrational wavenumbers are now determined in the S1 state and cation, as well as those of the D10 vibration. We also compare to the activity seen in the corresponding S1 ← S0 spectrum of para-difluorobenzene.
Stripe distribution on graphene-coated Cu surface and its effect on oxidation and corrosion resistance of graphene
Authors: Zhang Yanhui , Zhang Haoran , Chen Zhiying , Ge Xiaoming , Liang Yijian , Hu Shike , Deng Rongxuan , Sui Yan-ping , Yu Guang-hui
Published: June 2017

The morphology and distribution of the stripes caused by Cu surface reconstruction were measured, and the effects of stripes on graphene stability were studied by oxidation and corrosion. The results reveal that the stripes are determined by the crystal orientation of both the Cu surface and graphene, which can both change the stripe distribution, and the stripes can also be influenced by the graphene thickness. The stripes would not induce cracks or destruction to the graphene. The oxidation resistance of graphene can be improved by Cu surface reconstruction. The local nonuniform distortion of the stripe area may induce a bigger strain in the graphene which, in turn, may induce structure instability and result in local stability degeneration in the stripe area.
Structure-based sampling and self-correcting machine learning for accurate calculations of potential energy surfaces and vibrational levels
Authors: Dral Pavlo O. , Owens Alec , Yurchenko Sergei N. , Thiel Walter
Published: June 2017

We present an efficient approach for generating highly accurate molecular potential energy surfaces (PESs) using self-correcting, kernel ridge regression (KRR) based machine learning (ML). We introduce structure-based sampling to automatically assign nuclear configurations from a pre-defined grid to the training and prediction sets, respectively. Accurate high-level ab initio energies are required only for the points in the training set, while the energies for the remaining points are provided by the ML model with negligible computational cost. The proposed sampling procedure is shown to be superior to random sampling and also eliminates the need for training several ML models. Self-correcting machine learning has been implemented such that each additional layer corrects errors from the previous layer. The performance of our approach is demonstrated in a case study on a published high-level ab initio PES of methyl chloride with 44 819 points. The ML model is trained on sets of different sizes and then used to predict the energies for tens of thousands of nuclear configurations within seconds. The resulting datasets are utilized in variational calculations of the vibrational energy levels of CH3Cl. By using both structure-based sampling and self-correction, the size of the training set can be kept small (e.g., 10% of the points) without any significant loss of accuracy. In ab initio rovibrational spectroscopy, it is thus possible to reduce the number of computationally costly electronic structure calculations through structure-based sampling and self-correcting KRR-based machine learning by up to 90%.
On the computations of interatomic Coulombic decay widths with R-matrix method
Authors: Sisourat Nicolas , Engin Selma , Gorfinkiel Jimena D. , Kazandjian Sévan , Kolorenč Přemysl , Miteva Tsveta
Published: June 2017

Interatomic Coulombic Decay (ICD) is a general mechanism in which an excited atom can transfer its excess energy to a neighbor which is thus ionized. ICD belongs to the family of Feshbach resonance processes, and, as such, states undergoing ICD are characterized by their energy width. In this work, we investigate the computations of ICD widths using the R-matrix method as implemented in the UKRmol package. Helium dimer is used here as a benchmark system. The results are compared with those obtained with the well established Fano-Algebraic Diagrammatic Construction method. It is shown that the R-matrix method in its present implementation provides accurate total and partial widths if the kinetic energy of the ICD electron is lower than 10 eV. Advantages and limitations of the R-matrix method on the computations of ICD widths are discussed.
Optimizing symmetry-based recoupling sequences in solid-state NMR by pulse-transient compensation and asynchronous implementation
Authors: Hellwagner Johannes , Sharma Kshama , Tan Kong Ooi , Wittmann Johannes J. , Meier Beat H. , Madhu P. K. , Ernst Matthias
Published: June 2017

Pulse imperfections like pulse transients and radio-frequency field maladjustment or inhomogeneity are the main sources of performance degradation and limited reproducibility in solid-state nuclear magnetic resonance experiments. We quantitatively analyze the influence of such imperfections on the performance of symmetry-based pulse sequences and describe how they can be compensated. Based on a triple-mode Floquet analysis, we develop a theoretical description of symmetry-based dipolar recoupling sequences, in particular, R26411, calculating first- and second-order effective Hamiltonians using real pulse shapes. We discuss the various origins of effective fields, namely, pulse transients, deviation from the ideal flip angle, and fictitious fields, and develop strategies to counteract them for the restoration of full transfer efficiency. We compare experimental applications of transient-compensated pulses and an asynchronous implementation of the sequence to a supercycle, SR26, which is known to be efficient in compensating higher-order error terms. We are able to show the superiority of R26 compared to the supercycle, SR26, given the ability to reduce experimental error on the pulse sequence by pulse-transient compensation and a complete theoretical understanding of the sequence.
Edge-illumination x-ray phase contrast imaging with Pt-based metallic glass masks
Authors: Saghamanesh Somayeh , Aghamiri Seyed Mahmoud-Reza , Olivo Alessandro , Sadeghilarijani Maryam , Kato Hidemi , Kamali-Asl Alireza , Yashiro Wataru
Published: June 2017

Edge-illumination x-ray phase contrast imaging (EI XPCI) is a non-interferometric phase-sensitive method where two absorption masks are employed. These masks are fabricated through a photolithography process followed by electroplating which is challenging in terms of yield as well as time- and cost-effectiveness. We report on the first implementation of EI XPCI with Pt-based metallic glass masks fabricated by an imprinting method. The new tested alloy exhibits good characteristics including high workability beside high x-ray attenuation. The fabrication process is easy and cheap, and can produce large-size masks for high x-ray energies within minutes. Imaging experiments show a good quality phase image, which confirms the potential of these masks to make the EI XPCI technique widely available and affordable.
Noise, gain, and capture probability of p-type InAs-GaAs quantum-dot and quantum dot-in-well infrared photodetectors
Authors: Wolde Seyoum , Lao Yan-Feng , Unil Perera A. G. , Zhang Y. H. , Wang T. M. , Kim J. O. , Schuler-Sandy Ted , Tian Zhao-Bing , Krishna S.
Published: June 2017

We report experimental results showing how the noise in a Quantum-Dot Infrared photodetector (QDIP) and Quantum Dot-in-a-well (DWELL) varies with the electric field and temperature. At lower temperatures (below ∼100 K), the noise current of both types of detectors is dominated by generation-recombination (G-R) noise which is consistent with a mechanism of fluctuations driven by the electric field and thermal noise. The noise gain, capture probability, and carrier life time for bound-to-continuum or quasi-bound transitions in DWELL and QDIP structures are discussed. The capture probability of DWELL is found to be more than two times higher than the corresponding QDIP. Based on the analysis, structural parameters such as the numbers of active layers, the surface density of QDs, and the carrier capture or relaxation rate, type of material, and electric field are some of the optimization parameters identified to improve the gain of devices.
Model of ultrafast demagnetization driven by spin-orbit coupling in a photoexcited antiferromagnetic insulator Cr2O3
Authors: Guo Feng , Zhang Na , Jin Wei , Chang Jun
Published: June 2017

We theoretically study the dynamic time evolution following laser pulse pumping in an antiferromagnetic insulator Cr2O3. From the photoexcited high-spin quartet states to the long-lived low-spin doublet states, the ultrafast demagnetization processes are investigated by solving the dissipative Schrödinger equation. We find that the demagnetization times are of the order of hundreds of femtoseconds, in good agreement with recent experiments. The switching times could be strongly reduced by properly tuning the energy gaps between the multiplet energy levels of Cr3+. Furthermore, the relaxation times also depend on the hybridization of atomic orbitals in the first photoexcited state. Our results suggest that the selective manipulation of the electronic structure by engineering stress-strain or chemical substitution allows effective control of the magnetic state switching in photoexcited insulating transition-metal oxides.
Photoinduced charge carriers' accumulation and its impact on random lasing in Nd3+ doped (Pb,La)(Zr,Ti)O3 ceramics
Authors: Xu Caixia , Zhang Jingwen , Xu Long , Ma Xinyan , Zhao Hua
Published: June 2017

To pinpoint the driving forces behind the random lasing in Nd3+ doped lanthanum lead zirconate titanate (Nd:PLZT) ceramic plates, a combinatorial cavity with two gain media (Nd:YVO4 and Nd:PLZT) was used to study the switching feature between conventional lasing and random lasing oscillations. The complex laser output dynamics observed hinted that the photo-induced charge accumulation on the plate surface and the grain boundaries of Nd:PLZT is responsible for the lasing action switching, which was confirmed by a series of experiments, including strong electro-induced scattering, remarkable photoinduced currents, and light transmission reduction, along with measured single-pass-gain over the theoretical limit. It was found that the charge accumulation results in optical energy storage and nonuniform refractive index and hence strong scattering, which give rise to the random walks and weak localization of photons and long lasting lasing action and mode switching.
Non-local Ohm's law during collisions of magnetic flux ropes
Authors: Gekelman W. , DeHaas T. , Pribyl P. , Vincena S. , Van Compernolle B. , Sydora R.
Published: June 2017

Two kink unstable magnetic flux ropes are produced in a carefully diagnosed laboratory experiment. Using probes, the time varying magnetic field, plasma potential, plasma flow, temperature, and density were measured at over 42 000 spatial locations. These were used to derive all the terms in Ohm's law to calculate the plasma resistivity. The resistivity calculated by this method was negative in some spatial regions and times. Ohm's law was shown to be non-local. Instead, the Kubo resistivity at the flux rope kink frequency was calculated using the fluctuation dissipation theorem. The resistivity parallel to the magnetic field was as large as 40 times the classical value and peaked where magnetic field line reconnection occurred as well as in the regions of large flux rope current.
New study provides guide on how to make your own hyperuniform system
Authors: Bello Mark
Published: June 2017

Novel hidden long-range order can yield materials with special properties.
Triplet–triplet energy transfer in artificial and natural photosynthetic antennas
Authors: Ho Junming , Kish Elizabeth , Méndez-Hernández Dalvin D. , WongCarter Katherine , Pillai Smitha , Kodis Gerdenis , Niklas Jens , Poluektov Oleg G. , Gust Devens , Moore Thomas A. , Moore Ana L. , Batista Victor S. , Robert Bruno
Published: June 2017

Significance

Rapid chlorophyll-to-carotenoid triplet–triplet energy transfer (T-TET) in photosynthetic organisms is crucial to photoprotection from singlet oxygen. Photosynthesis reengineered for increased efficiency will result in increased oxygen levels in the cells, and the need to ensure adequately rapid T-TET will arise. Using a combination of theoretical and experimental studies on artificial and natural carotenoid–chlorophyll complexes, we have identified spectroscopic markers indicative of specific pigment–pigment interactions promoting fast T-TET. These interactions comprise essential design principles necessary for photoprotection in reengineered photosynthesis. Antenna systems from anoxygenic organisms suitably reengineered for photoprotection could be used to gather solar energy in the near infrared, which would markedly increase photosynthetic efficiency by better matching the solar spectrum to water oxidation and CO2reduction.
Protein homeostasis of a metastable subproteome associated with Alzheimer’s disease
Authors: Kundra Rishika , Ciryam Prajwal , Morimoto Richard I. , Dobson Christopher M. , Vendruscolo Michele
Published: June 2017

Significance

Alzheimer’s disease is a neurodegenerative disorder whose molecular origins have been associated with the dysregulation of a set of metastable proteins prone to aggregation. Under conditions of cellular and organismal health, the protein homeostasis system prevents effectively the misfolding and aggregation of these metastable proteins. Although it is well established that such regulatory mechanisms become progressively impaired with aging, resulting in an accumulation of protein deposits, the specific nature of such impairment has remained incompletely characterized. Through a gene coexpression analysis, here we identify the endosomal–lysosomal and ubiquitin–proteasome systems, and more generally the protein trafficking and clearance mechanisms, as key components of the protein homeostasis system that maintains the metastable proteins in their functional states.
Nonenzymatic gluconeogenesis-like formation of fructose 1,6-bisphosphate in ice
Authors: Messner Christoph B. , Driscoll Paul C. , Piedrafita Gabriel , De Volder Michael F. L. , Ralser Markus
Published: June 2017

Significance

It is still unknown how an early metabolism produced the sugar phosphates central for life. We provide evidence that gluconeogenesis, the anabolic counterpart to glycolysis, could have emerged nonenzymatically. We describe that the gluconeogenic carbon-bond–forming reaction has a nonenzymatic pendant that occurs in ice and that leads to the accumulation of fructose 1,6-bisphosphate as (re-)built from glycolytic catabolites. As a nonenzymatic glycolysis has been described previously, the discovery of this reaction could both help to explain the origin of the larger cellular sugar phosphates and provide a scenario in which an early metabolic system was able to escape equilibrium. The reaction further hints that the earliest anabolic enzymes could have been as simple as single amino acids.
Rapid phenotypic antimicrobial susceptibility testing using nanoliter arrays
Authors: Avesar Jonathan , Rosenfeld Dekel , Truman-Rosentsvit Marianna , Ben-Arye Tom , Geffen Yuval , Bercovici Moran , Levenberg Shulamit
Published: June 2017

Significance

Antibiotic resistance is fueled by antibiotic misuse and has become a major global health concern. The phenomenon warrants improved diagnostics that can more rapidly and efficiently elucidate information about the infectious agent to aid in establishing a more targeted and knowledge-based treatment regimen. This paper introduces a rapid antibiotic susceptibility test and automated data analysis algorithm that can, unlike traditional methods, deliver results on the same working day in an efficient and translatable manner for clinical use. This paper also introduces a method for direct urine testing that can help save days of diagnosis time. The platform is expected to promote more judicious use of antibiotics, thereby reducing the emergence of antibiotic resistance, lowering healthcare costs and ultimately saving lives.
Spatially resolved multicolor CsPbX
3
nanowire heterojunctions via anion exchange
Authors: Dou Letian , Lai Minliang , Kley Christopher S. , Yang Yiming , Bischak Connor G. , Zhang Dandan , Eaton Samuel W. , Ginsberg Naomi S. , Yang Peidong
Published: June 2017

Significance

Semiconductor heterojunction is a key building block in modern electronics and optoelectronics. The accurate control over the composition, band gap, energy level (band bending), and doping level is the foundation of ideal functional heterojunctions. We demonstrate highly spatially resolved heterojunctions in a type of semiconductor, halide perovskites, which show great potential in photovoltaic and solid-state lighting applications. We accomplish this through the combination of facile anion-exchange chemistry with nanofabrication techniques. The halide perovskite nanowire heterojunction provides an ideal platform for fundamental studies and technological applications. For example, multicolor lasers or LEDs could be made using such localized heterojunctions; quantitative interdiffusion and ion migration dynamics could be examined at elevated temperatures, etc.
Evolution of immune chemoreceptors into sensors of the outside world
Authors: Dietschi Quentin , Tuberosa Joël , Rösingh Lone , Loichot Gregory , Ruedi Manuel , Carleton Alan , Rodriguez Ivan
Published: June 2017

Significance

Immune formyl peptide receptors (Fprs) evolved in rodents from expression in immune cells to be transcribed in olfactory sensory neurons. Explaining the initial neuronal acquisition, we found that an Fpr coding exon landed in front of a vomeronasal receptor promoter, hijacking its expression pattern. This type of gene shuffling occurred twice in the mouse lineage, many million years apart, leading to the exclusive expression of Fprs in the two main populations of vomeronasal sensory neurons. Finally, we demonstrate that the immune expression of one of the mouse vomeronasal Fprs can be restored via the production of an intergenic transcript. Thus, we provide the complete history of genomic events that led to a model case of evolutionary neofunctionalization in a mammal.
Optimal multivalent targeting of membranes with many distinct receptors
Authors: Curk Tine , Dobnikar Jure , Frenkel Daan
Published: June 2017

Significance

A key challenge in biomedical research is the ability to specifically target cells and tissues. Targeting typically relies on identifying a suitable marker, e.g., a highly expressed receptor, and choosing a ligand that strongly and specifically binds to the marker. However, this procedure fails when a suitable marker unique to the targeted cells cannot be identified, notably in many forms of cancer. We show that properly designed multivalent targeting of multiple cognate receptor types results in a specificity toward a chosen receptor density profile, thus demonstrating a general route toward targeting cells without particularly dominant markers.
Dissecting and modeling zeaxanthin- and lutein-dependent nonphotochemical quenching in
Arabidopsis thaliana
Authors: Leuenberger Michelle , Morris Jonathan M. , Chan Arnold M. , Leonelli Lauriebeth , Niyogi Krishna K. , Fleming Graham R.
Published: June 2017

Significance

The balance between light harvesting and photoprotection is a critical component of photosynthetic efficiency and must be maintained in fluctuating light conditions. Two xanthophylls play key roles in the vascular plant response to changes in light intensity: zeaxanthin and lutein. Chlorophyll fluorescence decay studies of
Arabidopsis thaliana
mutants enabling the isolation of individual contributions of zeaxanthin and lutein to the response and a kinetic model of quenching make it possible to model the mutant data and predict the combined influence of zeaxanthin and lutein on nonphotochemical quenching in WT
A. thaliana
with the use of a single scaling factor. The model informs efforts to improve the response of plants to fluctuating light in natural environments and increase crop yields.
Simulating tactile signals from the whole hand with millisecond precision
Authors: Saal Hannes P. , Delhaye Benoit P. , Rayhaun Brandon C. , Bensmaia Sliman J.
Published: June 2017

Significance

When we grasp an object, thousands of tactile nerve fibers become activated and inform us about its physical properties (e.g., shape, size, and texture). Although the properties of individual fibers have been described, our understanding of how object information is encoded in populations of fibers remains primitive. To fill this gap, we have developed a simulation of tactile fibers that incorporates much of what is known about skin mechanics and tactile nerve fibers. We show that simulated fibers match biological ones across a wide range of conditions sampled from the literature. We then show how this simulation can reveal previously unknown ways in which populations of nerve fibers cooperate to convey sensory information and discuss the implications for bionic hands.
CIDE domains form functionally important higher-order assemblies for DNA fragmentation
Authors: Choi Jae Young , Qiao Qi , Hong Se-Hoon , Kim Chang Min , Jeong Jae-Hee , Kim Yeon-Gil , Jung Yong-Keun , Wu Hao , Park Hyun Ho
Published: June 2017

Significance

Cell death-inducing DFF45-like effector (CIDE) domains, initially identified in apoptotic nucleases, form a highly conserved family with diverse functions ranging from cell death to lipid homeostasis and synaptic regulation. Through structural determination of two CIDE family proteins, Drep2 and Drep4, we found that CIDE domains can form helical oligomers. Our results reveal that such higher-order structures not only are conserved in the CIDE family, but also are critically important for both DNA fragmentation and lipid droplet fusion. Therefore, our findings identify the CIDE domain as a scaffolding component for higher-order structure assembly. Our results expand the importance of higher-order structures from the established field of immune signaling to broader biological functions.
Quantitative proteomics identify Tenascin-C as a promoter of lung cancer progression and contributor to a signature prognostic of patient survival
Authors: Gocheva Vasilena , Naba Alexandra , Bhutkar Arjun , Guardia Talia , Miller Kathryn M. , Li Carman Man-Chung , Dayton Talya L. , Sanchez-Rivera Francisco J. , Kim-Kiselak Caroline , Jailkhani Noor , Winslow Monte M. , Del Rosario Amanda , Hynes Richard O. , Jacks Tyler
Published: June 2017

Significance

Quantitative mass spectrometric profiling of the extracellular matrix composition of normal lung, fibrotic lung, primary lung tumors, and lung metastases to the lymph nodes uncovered specific signatures distinguishing these tissues. CRISPR/Cas9-mediated gene activation of one of the identified factors, Tenascin-C (Tnc), showed that this protein plays a role in mediating lung adenocarcinoma metastasis. Tnc expression is repressed, directly or indirectly, by the transcription factor Nkx2-1. Bioinformatic analysis shows that expression of three matrisome factors (TNC,S100A10, andS100A11) can predict survival in patients with lung adenocarcinoma. These factors could serve as disease markers that could be exploited for better diagnosis of lung cancer, and their future study could be used to inform the design of more potent treatments for patients.
CRISPR-Cas9 conformational activation as elucidated from enhanced molecular simulations
Authors: Palermo Giulia , Miao Yinglong , Walker Ross C. , Jinek Martin , McCammon J. Andrew
Published: June 2017

Significance

The CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats–CRISPR-associated protein 9) system recently emerged as a transformative genome editing technology that is innovating life science, with cutting-edge impact in biomedicine, pharmaceutics, and agriculture. Nevertheless, the molecular mechanism underlying CRISPR-Cas9 function is still incompletely understood. Here, enhanced molecular dynamics (MD) simulations, probing displacements over long timescales, capture at atomic level specific features that are difficult to reach via conventional MD simulations and via the currently available experimental techniques, clarifying the molecular mechanism of CRISPR-Cas9, with understanding of its activation process. The insights obtained from our molecular simulations provide key reference points for future experimental studies of CRISPR-Cas9 and its applications as a genome editing tool.
Reconstruction from limited single-particle diffraction data via simultaneous determination of state, orientation, intensity, and phase
Authors: Donatelli Jeffrey J. , Sethian James A. , Zwart Peter H.
Published: June 2017

Significance

Single-particle diffraction is an emerging technique in which diffraction images are collected from individual particles, and is used to study molecular structure from multiple conformational states that may be inaccessible through other methods. However, determining structure from these experiments is challenging, since orientations and states of imaged particles are unknown and images are highly contaminated with noise. Furthermore, the number of useful images is often limited by achievable single-particle hit rates, currently around 0.1%. We introduce an iterative projection framework to simultaneously determine orientations, states, and molecular structure from limited single-particle data by leveraging structural constraints throughout the reconstruction. This framework offers a potential pathway to increasing the amount of information that can be extracted from single-particle diffraction.
Online retellings and the viral transformation of a twitter breakup story
Authors: De Fina Anna , Gore Brittany Toscano
Published: June 2017

The retelling and sharing of stories is not a new phenomenon. Many narrative analysts have devoted research to these processes. But the culture of participation (Jenkins 2006) in the digital world has brought sharing to a completely new level by allowing users not only to broadcast their opinions and evaluations of a story but also to reappropriate it and recontextualize it in infinite recursions. We focus on such process of transformation of a narrative in different media and social media outlets through the analysis of the viral spread of a story posted by an individual Twitter user in 2015. Specifically, we illustrate how participation frameworks change from one retelling to another and how the original story becomes "nested" into a new meta-story centered on the twitter user as a character and on the viral spread of the story.
Recontextualizing racialized stories on YouTube
Authors: Perrino Sabina
Published: June 2017

When stories (re)appear in YouTube videos, they are recontextualized not only by their titling and editing, but especially by chains of online comments. This article explores how a Northern Italian politician’s racialized story, which was first recontextualized by a TV news reporter on a YouTube video, is further recontextualized for different ends by commenters on that video. I show how these commenters negotiate and reframe the racial aspects of digital discourse and its sociocultural meanings through their various responses and across different temporal and spatial scales. By applying linguistic anthropological and sociolinguistic theories and narrative analytical tools to digital storytelling, this study emphasizes how racialized language is neither stable nor unidirectional, but is rather constantly negotiated discursively among various groups of virtual audience members. Besides investigating the pragmatics of narrative interaction in the digital realm, this article speaks to methodological challenges that surround the study of online storytelling.
Sharing the moment as small stories
Authors: Georgakopoulou Alexandra
Published: June 2017

Sharing the moment live, a built-in logic of many social networking sites, is, I claim, an invitation for creating plots, which has led to systematic practices. I single out taking a narrative stance on Facebook as such a practice and show the interplay between key-norms and evolving media affordances for pre-selection of story ingredients, localization, visualization of the experience, and audience selection. These contribute to showing the moment as opposed to telling it, with selected friends serving as knowing co-narrators and with story-linking allowing for allusive, transmedia links. I review these practices in the context of increased story facilities that notably bring together several social media apps. I argue that although this curation promises a move beyond the moment, it ultimately serves to consolidate sharing-lives-in-the-moment. I reflect on the implications of this for the direction of travel in relation to stories on many social media platforms.