bluuebunny/crossref_metadata_2025 huggingface dataset:
Drainage from the Critical Zone: Lithologic Controls on the Persistence and Spatial Extent of Wetted Channels during the Summer Dry Season
Authors: Lovill S. M. , Hahm W. J. , Dietrich W.E.
Published: May 2018

In seasonally dry environments, critical zone drainage provides base flow that sustains river ecosystems. The extent of wetted channels and magnitude of base flow throughout the network, however, are rarely documented, and no general theory currently exists enabling the prediction of these key ecosystem properties. We conducted channel surveys in early and late summers of 2012, 2014, and 2015 in four headwater drainage networks (2.8–17.0 km2, in the Franciscan Formation of the Eel River (Northern California)), two of which are underlain by the Coastal Belt (argillite and inter‐bedded sandstone) and two of which are underlain by the Central Belt (sheared argillaceous‐matrix, meta‐sedimentary mélange). In all networks, stationary springs controlled the extent of flow. Though surveyed during a period of multiyear drought, the two adjacent Coastal Belt networks remained flowing throughout late‐summer months, sustained by drainage from groundwater stored in thick weathered bedrock above fresh, impermeable bedrock. Flow magnitudes, however, decreased and surface flows became increasingly discontinuous, largely due to infiltration into thick gravel deposits on the channel bed. Only 23 km away, in the Central Belt mélange, channel flow ceased early in the summer because the thin critical zone (typically <3 m) stored little water. All late‐summer flowing water initiated from deep‐rooted sandstone blocks and terminated a short distance downslope. Our findings suggest that lithology and critical zone development exert primary controls on wetted channel extent. Given similar annual precipitation, nearby watersheds can have dramatically different summer wetted channel networks that result in fundamentally different aquatic ecosystems.
Kinetic Dissipation Around a Dipolarization Front
Authors: Sitnov M. I. , Merkin V. G. , Roytershteyn V. , Swisdak M.
Published: May 2018

Kinetic aspects of energy conversion and dissipation near a dipolarization front (DF) in the magnetotail are considered using fully kinetic 3‐D particle‐in‐cell simulations. The energy conversion is described in terms of the pressure dilatation, as well as the double contraction of deviatoric pressure tensor and traceless strain rate tensor, also known as the Pi‐D parameter in turbulence studies. It is shown that in contrast to the fluid dissipation measure, the Joule heating rate, which cannot distinguish between ion and electron dissipation and reveals deep negative dips at the DF, the Pi‐D parameters, as kinetic analogs of the Joule heating rate, are largely positive and drastically different for ions and electrons. Further analysis of these parameters suggests that ions are heated at and ahead of the DF due to their reflection from the front, while electrons are heated at and behind the DF due to the long‐wavelength lower‐hybrid drift instability.
Thank You to Space Weather Peer Reviewers
Authors: Knipp Delores J. , O'Brien T. Paul , Welling Daniel T. , Hapgood Michael
Published: May 2018

Space Weather Editors recognize contribution from peer reviewers.
Spectroscopic stimulated Raman scattering imaging of highly dynamic specimens through matrix completion
Authors: Lin Haonan , Liao Chien-Sheng , Wang Pu , Kong Nan , Cheng Ji-Xin
Published: May 2018

Spectroscopic stimulated Raman scattering (SRS) imaging generates chemical maps of intrinsic molecules, with no need for prior knowledge. Despite great advances in instrumentation, the acquisition speed for a spectroscopic SRS image stack is fundamentally bounded by the pixel integration time. In this work, we report three-dimensional sparsely sampled spectroscopic SRS imaging that measures ~20% of pixels throughout the stack. In conjunction with related work in low-rank matrix completion (e.g., the Netflix Prize), we develop a regularized non-negative matrix factorization algorithm to decompose the sub-sampled image stack into spectral signatures and concentration maps. This design enables an acquisition speed of 0.8 s per image stack, with 50 frames in the spectral domain and 40,000 pixels in the spatial domain, which is faster than the conventional raster laser-scanning scheme by one order of magnitude. Such speed allows real-time metabolic imaging of living fungi suspended in a growth medium while effectively maintaining the spatial and spectral resolutions. This work is expected to promote broad application of matrix completion in spectroscopic laser-scanning imaging.
A real-time detection and positioning method for small and weak targets using a 1D morphology-based approach in 2D images
Authors: Wei Min-Song , Xing Fei , You Zheng
Published: May 2018

A small and weak target detection method is proposed in this work that outperforms all other methods in terms of real-time capability. It is the first time that two-dimensional (2D) images are processed using only one-dimensional1D structuring elements in a morphology-based approach, enabling the real-time hardware implementation of the whole image processing method. A parallel image readout and processing structure is introduced to achieve an ultra-low latency time on the order of nanoseconds, and a hyper-frame resolution in the time domain can be achieved by combining the row-by-row structure and the electrical rolling shutter technique. Experimental results suggest that the expected target can be successfully detected under various interferences with an accuracy of 0.1 pixels (1σ) under the worst sky night test condition and that a centroiding precision of better than 0.03 pixels (1σ) can be reached for static tests. The real-time detection method with high robustness and accuracy is attractive for application to all types of real-time small target detection systems, such as medical imaging, infrared surveillance, and target measurement and tracking, where an ultra-high processing speed is required.
Microfluidics-enabled phenotyping of a whole population of C. elegans worms over their embryonic and post-embryonic development at single-organism resolution
Authors: Letizia Maria Cristina , Cornaglia Matteo , Trouillon Raphaël , Sorrentino Vincenzo , Mouchiroud Laurent , Bou Sleiman Maroun S. , Auwerx Johan , Gijs Martin A. M.
Published: May 2018

The organism Caenorhabditis elegans is a performant model system for studying human biological processes and diseases, but until now all phenome data are produced as population-averaged read-outs. Monitoring of individual responses to drug treatments would however be more informative. Here, a new strategy to track different phenotypic traits of individual C. elegans nematodes throughout their full life-cycle—i.e., embryonic and post-embryonic development, until adulthood onset, differently from life-span—is presented. In an automated fashion, single worms were synchronized, isolated, and cultured from egg to adulthood in a microfluidic device, where their identity was preserved during their whole development. Several phenotypes were monitored and quantified for each animal, resulting in high-content phenome data. Specifically, the method was validated by analyzing the response of C. elegans to doxycycline, an antibiotic fairly well-known to prolong the development and activate mitochondrial stress-response pathways in different species. Interestingly, the obtained extensive single-worm phenome not only confirmed the dramatic doxycycline effect on the worm developmental delay, but more importantly revealed subtle yet severe treatment-dependent phenotypes that are representative of minority subgroups and would have otherwise stayed hidden in an averaged dataset. Such heterogeneous response started during the embryonic development, which makes essential having a dedicated chip that allows including this early developmental stage in the drug assay. Our approach would therefore allow elucidating pharmaceutical or therapeutic responses that so far were still being overlooked.
CRISPR-LbCpf1 prevents choroidal neovascularization in a mouse model of age-related macular degeneration
Authors: Koo Taeyoung , Park Sung Wook , Jo Dong Hyun , Kim Daesik , Kim Jin Hyoung , Cho Hee-Yeon , Kim Jeungeun , Kim Jeong Hun , Kim Jin-Soo
Published: May 2018

LbCpf1, derived from Lachnospiraceae bacterium ND2006, is a CRISPR RNA-guided endonuclease and holds promise for therapeutic applications. Here we show that LbCpf1 can be used for therapeutic gene editing in a mouse model of age-related macular degeneration (AMD). The intravitreal delivery of LbCpf1, targeted to two angiogenesis-associated genes encoding vascular endothelial growth factor A (Vegfa) and hypoxia inducing factor 1a (Hif1a), using adeno-associated virus, led to efficient gene disruption with no apparent off-target effects in the retina and retinal pigment epithelium (RPE) cells. Importantly, LbCpf1 targeted to Vegfa or Hif1a in RPE cells reduced the area of laser-induced choroidal neovascularization as efficiently as aflibercept, an anti-VEGF drug currently used in the clinic, without inducing cone dysfunction. Unlike aflibercept, LbCpf1 targeted to Vegfa or Hif1a achieved a long-term therapeutic effect on CNV, potentially avoiding repetitive injections. Taken together, these results indicate that LbCpf1-mediated in vivo genome editing to ablate pathologic angiogenesis provides an effective strategy for the treatment of AMD and other neovascularization-associated diseases.
Single molecule fate of HIV-1 envelope reveals late-stage viral lattice incorporation
Authors: Buttler Carmen A. , Pezeshkian Nairi , Fernandez Melissa V. , Aaron Jesse , Norman Sofya , Freed Eric O. , van Engelenburg Schuyler B.
Published: May 2018

Human immunodeficiency virus type 1 (HIV-1) assembly occurs on the inner leaflet of the host cell plasma membrane, incorporating the essential viral envelope glycoprotein (Env) within a budding lattice of HIV-1 Gag structural proteins. The mechanism by which Env incorporates into viral particles remains poorly understood. To determine the mechanism of recruitment of Env to assembly sites, we interrogate the subviral angular distribution of Env on cell-associated virus using multicolor, three-dimensional (3D) superresolution microscopy. We demonstrate that, in a manner dependent on cell type and on the long cytoplasmic tail of Env, the distribution of Env is biased toward the necks of cell-associated particles. We postulate that this neck-biased distribution is regulated by vesicular retention and steric complementarity of Env during independent Gag lattice formation.
Determination of hot carrier energy distributions from inversion of ultrafast pump-probe reflectivity measurements
Authors: Heilpern Tal , Manjare Manoj , Govorov Alexander O. , Wiederrecht Gary P. , Gray Stephen K. , Harutyunyan Hayk
Published: May 2018

Developing a fundamental understanding of ultrafast non-thermal processes in metallic nanosystems will lead to applications in photodetection, photochemistry and photonic circuitry. Typically, non-thermal and thermal carrier populations in plasmonic systems are inferred either by making assumptions about the functional form of the initial energy distribution or using indirect sensors like localized plasmon frequency shifts. Here we directly determine non-thermal and thermal distributions and dynamics in thin films by applying a double inversion procedure to optical pump-probe data that relates the reflectivity changes around Fermi energy to the changes in the dielectric function and in the single-electron energy band occupancies. When applied to normal incidence measurements our method uncovers the ultrafast excitation of a non-Fermi-Dirac distribution and its subsequent thermalization dynamics. Furthermore, when applied to the Kretschmann configuration, we show that the excitation of propagating plasmons leads to a broader energy distribution of electrons due to the enhanced Landau damping.
L-proline mixed with sodium benzoate as sustainable inhibitor for mild steel corrosion in 1M HCl: An experimental and theoretical approach
Authors: Parveen Mosarrat , Mobin Mohammad , Zehra Saman , Aslam Ruby
Published: May 2018

Following standard experimental (gravimetric measurements, potentiodynamic polarization measurements, electrochemical impedance measurements, spectroscopic measurements, scanning electron microscopy technique) and theoretical (DFT) approach, inhibition effect of L-proline (LPr) and LPr mixed with sodium benzoate (LPr + NaBenz) for mild steel (MS) corrosion in 1M HCl was studied at 30, 40, 50 and 60 °C. The concentration of LPr was varied between 100–600 ppm, whereas that of NaBenz was fixed at 10 ppm. LPr lowered the corrosion rates of MS to a considerable extent. Corrosion mitigating efficacy of LPr is synergistically enhanced on adding NaBenz at all concentrations. Evaluation of polarization parameters suggested that both LPr and LPr + NaBenz act as mixed type inhibitor with more control on cathodic reaction whereas impedance parameters suggested inhibition of metal corrosion by adsorption at the MS/solution interface. Surface microscopic examination of corroded and uncorroded MS coupons supported the protective effect of adsorbed inhibitor layer at the MS surface. Spectroscopic studies are suggestive of the complex formation between inhibitor molecules and the metal. When LPr is combined with NaBenz, the corrosion inhibition rate was improved greatly. Corrosion mitigating efficacy of LPr or LPr mixed with NaBenz obtained by different techniques are in good agreement and correlate well with theoretical quantum chemical descriptors.
Revealing the nature of morphological changes in carbon nanotube-polymer saturable absorber under high-power laser irradiation
Authors: Chernysheva Maria , Araimi Mohammed Al , Rance Graham A. , Weston Nicola J. , Shi Baogui , Saied Sayah , Sullivan John L. , Marsh Nicholas , Rozhin Aleksey
Published: May 2018

Composites of single-walled carbon nanotubes (SWNTs) and water-soluble polymers (WSP) are the focus of significant worldwide research due to a number of applications in biotechnology and photonics, particularly for ultrashort pulse generation. Despite the unique possibility of constructing non-linear optical SWNT-WSP composites with controlled optical properties, their thermal degradation threshold and limit of operational power remain unexplored. In this study, we discover the nature of the SWNT-polyvinyl alcohol (PVA) film thermal degradation and evaluate the modification of the composite properties under continuous high-power ultrashort pulse laser operation. Using high-precision optical microscopy and micro-Raman spectroscopy, we have examined SWNT-PVA films before and after continuous laser radiation exposure (up to 40 hours) with a maximum optical fluence of 2.3 mJ·cm−2. We demonstrate that high-intensity laser radiation results in measurable changes in the composition and morphology of the SWNT-PVA film due to efficient heat transfer from SWNTs to the polymer matrix. The saturable absorber modification does not affect the laser operational performance. We anticipate our work to be a starting point for more sophisticated research aimed at the enhancement of SWNT-PVA films fabrication for their operation as reliable saturable absorbers in high-power ultrafast lasers.
Genomic features of renal cell carcinoma with venous tumor thrombus
Authors: Warsow Gregor , Hübschmann Daniel , Kleinheinz Kortine , Nientiedt Cathleen , Heller Martina , Van Coile Laura , Tolstov Yanis , Trennheuser Lukas , Wieczorek Kathrin , Pecqueux Carine , Gasch Claudia , Kuru Timur , Nyarangi-Dix Joanne , Hatiboglu Gencay , Teber Dogu , Perner Sven , Stenzinger Albrecht , Roth Wilfried , Hadaschik Boris , Pahernik Sascha , Jäger Dirk , Grüllich Carsten , Duensing Anette , Eils Roland , Schlesner Matthias , Sültmann Holger , Hohenfellner Markus , Duensing Stefan
Published: May 2018

A venous tumor thrombus (VTT) is a potentially lethal complication of renal cell carcinoma (RCC) but virtually nothing is known about the underlying natural history. Based on our observation that venous thrombi contain significant numbers of viable tumor cells, we applied multiregion whole exome sequencing to a total of 37 primary tumor and VTT samples including normal tissue specimens from five consecutive patients. Our findings demonstrate mutational heterogeneity between primary tumor and VTT with 106 of 483 genes (22%) harboring functional SNVs and/or indels altered in either primary tumor or thrombus. Reconstruction of the clonal phylogeny showed clustering of tumor samples and VTT samples, respectively, in the majority of tumors. However, no new subclones were detected suggesting that pre-existing subclones of the primary tumor drive VTT formation. Importantly, we found several lines of evidence for “BRCAness” in a subset of tumors. These included mutations in genes that confer “BRCAness”, a mutational signature and an increase of small indels. Re-analysis of SNV calls from the TCGA KIRC-US cohort confirmed a high frequency of the “BRCAness” mutational signature AC3 in clear cell RCC. Our findings warrant further pre-clinical experiments and may lead to novel personalized therapies for RCC patients.
Live-cell imaging of nuclear–chromosomal dynamics in bovine in vitro fertilised embryos
Authors: Yao Tatsuma , Suzuki Rie , Furuta Natsuki , Suzuki Yuka , Kabe Kyoko , Tokoro Mikiko , Sugawara Atsushi , Yajima Akira , Nagasawa Tomohiro , Matoba Satoko , Yamagata Kazuo , Sugimura Satoshi
Published: May 2018

Nuclear/chromosomal integrity is an important prerequisite for the assessment of embryo quality in artificial reproductive technology. However, lipid-rich dark cytoplasm in bovine embryos prevents its observation by visible light microscopy. We performed live-cell imaging using confocal laser microscopy that allowed long-term imaging of nuclear/chromosomal dynamics in bovine in vitro fertilised (IVF) embryos. We analysed the relationship between nuclear/chromosomal aberrations and in vitro embryonic development and morphological blastocyst quality. Three-dimensional live-cell imaging of 369 embryos injected with mRNA encoding histone H2B-mCherry and enhanced green fluorescent protein (EGFP)-α-tubulin was performed from single-cell to blastocyst stage for eight days; 17.9% reached the blastocyst stage. Abnormalities in the number of pronuclei (PN), chromosomal segregation, cytokinesis, and blastomere number at first cleavage were observed at frequencies of 48.0%, 30.6%, 8.1%, and 22.2%, respectively, and 13.0%, 6.2%, 3.3%, and 13.4%, respectively, for abnormal embryos developed into blastocysts. A multivariate analysis showed that abnormal chromosome segregation (ACS) and multiple PN correlated with delayed timing and abnormal blastomere number at first cleavage, respectively. In morphologically transferrable blastocysts, 30–40% of embryos underwent ACS and had abnormal PN. Live-cell imaging may be useful for analysing the association between nuclear/chromosomal dynamics and embryonic development in bovine embryos.
A rapid and nondestructive protocol for whole-mount bone staining of small fish and Xenopus
Authors: Sakata-Haga Hiromi , Uchishiba Maimi , Shimada Hiroki , Tsukada Tsuyoshi , Mitani Mayumi , Arikawa Tomohiro , Shoji Hiroki , Hatta Toshihisa
Published: May 2018

Here we propose a new protocol for whole-mount bone staining, which allows the rapid preparation of highly cleared and nondestructive specimens. It only takes 3 days to complete whole procedure for small vertebrates, such as medaka, zebrafish, and Xenopus frogs. In this procedure, we used a newly developed fixative containing formalin, Triton X-100, and potassium hydroxide, which allows the fixation, decolorization, and transparentization of specimens at the same time. A bone staining solution containing alizarin red S with ethylene glycol and a clearing solution containing Tween 20 and potassium hydroxide also contributed the specificity and swiftness of this new system. As expected, although details of the skeletal system could be observed in specimens with high transparency, it was noteworthy that high-resolution fluorescence images acquired using zoom microscopes clearly delineated the shape of each bone. This new procedure would be expected to be widely used as a standard procedure for bone staining in the testing the developmental toxicity of chemicals and in the screening test of knockout or mutant animals.
Novel erythrocyte clumps revealed by an orphan gene Newtic1 in circulating blood and regenerating limbs of the adult newt
Authors: Casco-Robles Roman M. , Watanabe Akihiko , Eto Ko , Takeshima Kazuhito , Obata Shuichi , Kinoshita Tsutomu , Ariizumi Takashi , Nakatani Kei , Nakada Tomoaki , Tsonis Panagiotis A. , Casco-Robles Martin M. , Sakurai Keisuke , Yahata Kensuke , Maruo Fumiaki , Toyama Fubito , Chiba Chikafumi
Published: May 2018

The newt, a group of urodele amphibians, has outstanding ability to repeatedly regenerate various body parts, even in the terrestrial life-stage. In this animal, when the limb is amputated, a cell mass named the blastema appears on the stump and eventually gives rise to a new functional limb. Erythrocytes (red blood cells) in most non-mammalian vertebrates, including the newt, preserve their nucleus throughout their life-span, although physiological roles of such nucleated erythrocytes, other than oxygen delivery, are not known. Here we report novel behavior of erythrocytes in the newt. We identified an orphan gene Newtic1, whose transcripts significantly increased in the blastema. Newtic1 was expressed in a subset of erythrocytes that formed a novel clump (EryC). EryC formed a complex with monocytes and was circulating throughout the body. When the limb was amputated, EryCs were newly generated in the stump and accumulated into a distal portion of the growing blastema. Our data suggested that the newt erythrocytes carried multiple secretory molecules including growth factors and matrix metalloproteases, and were capable of delivering these molecules into the blastema as a form of EryCs. This study provides insight into regulations and roles of nucleated erythrocytes, that are independent of oxygen delivery.
Humanizing Miniature Hearts through 4-Flow Cannulation Perfusion Decellularization and Recellularization
Authors: Nguyen Duong T. , O’Hara Matthew , Graneli Cecilia , Hicks Ryan , Miliotis Tasso , Nyström Ann-Christin , Hansson Sara , Davidsson Pia , Gan Li-Ming , Magnone Maria Chiara , Althage Magnus , Heydarkhan-Hagvall Sepideh
Published: May 2018

Despite improvements in pre-clinical drug testing models, predictability of clinical outcomes continues to be inadequate and costly due to poor evidence of drug metabolism. Humanized miniature organs integrating decellularized rodent organs with tissue specific cells are translational models that can provide further physiological understanding and evidence. Here, we evaluated 4-Flow cannulated rat hearts as the fundamental humanized organ model for cardiovascular drug validation. Results show clearance of cellular components in all chambers in 4-Flow hearts with efficient perfusion into both coronary arteries and cardiac veins. Furthermore, material characterization depicts preserved organization and content of important matrix proteins such as collagens, laminin, and elastin. With access to the complete vascular network, different human cell types were delivered to show spatial distribution and integration into the matrix under perfusion for up to three weeks. The feature of 4-Flow cannulation is the preservation of whole heart conformity enabling ventricular pacing via the pulmonary vein as demonstrated by noninvasive monitoring with fluid pressure and ultrasound imaging. Consequently, 4-Flow hearts surmounting organ mimicry challenges with intact complexity in vasculature and mechanical compliance of the whole organ providing an ideal platform for improving pre-clinical drug validation in addition to understanding cardiovascular diseases.
Cavitation-threshold Determination and Rheological-parameters Estimation of Albumin-stabilized Nanobubbles
Authors: Lafond Maxime , Watanabe Akiko , Yoshizawa Shin , Umemura Shin-ichiro , Tachibana Katsuro
Published: May 2018

Nanobubbles (NBs) are of high interest for ultrasound (US) imaging as contrast agents and therapy as cavitation nuclei. Because of their instability (Laplace pressure bubble catastrophe) and low sensitivity to US, reducing the size of commonly used microbubbles to submicron-size is not trivial. We introduce stabilized NBs in the 100–250-nm size range, manufactured by agitating human serum albumin and perfluoro-propane. These NBs were exposed to 3.34- and 5.39-MHz US, and their sensitivity to US was proven by detecting inertial cavitation. The cavitation-threshold information was used to run a numerical parametric study based on a modified Rayleigh-Plesset equation (with a Newtonian rheology model). The determined values of surface tension ranged from 0 N/m to 0.06 N/m. The corresponding values of dilatational viscosity ranged from 5.10−10 Ns/m to 1.10−9 Ns/m. These parameters were reported to be 0.6 N/m and 1.10−8 Ns/m for the reference microbubble contrast agent. This result suggests the possibility of using albumin as a stabilizer for the nanobubbles that could be maintained in circulation and presenting satisfying US sensitivity, even in the 3–5-MHz range.
3D confocal laser-scanning microscopy for large-area imaging of the corneal subbasal nerve plexus
Authors: Allgeier Stephan , Bartschat Andreas , Bohn Sebastian , Peschel Sabine , Reichert Klaus-Martin , Sperlich Karsten , Walckling Marcus , Hagenmeyer Veit , Mikut Ralf , Stachs Oliver , Köhler Bernd
Published: May 2018

The capability of corneal confocal microscopy (CCM) to acquire high-resolution in vivo images of the densely innervated human cornea has gained considerable interest in using this non-invasive technique as an objective diagnostic tool for staging peripheral neuropathies. Morphological alterations of the corneal subbasal nerve plexus (SNP) assessed by CCM have been shown to correlate well with the progression of neuropathic diseases and even predict future-incident neuropathy. Since the field of view of single CCM images is insufficient for reliable characterisation of nerve morphology, several image mosaicking techniques have been developed to facilitate the assessment of the SNP in large-area visualisations. Due to the limited depth of field of confocal microscopy, these approaches are highly sensitive to small deviations of the focus plane from the SNP layer. Our contribution proposes a new automated solution, combining guided eye movements for rapid expansion of the acquired SNP area and axial focus plane oscillations to guarantee complete imaging of the SNP. We present results of a feasibility study using the proposed setup to evaluate different oscillation settings. By comparing different image selection approaches, we show that automatic tissue classification algorithms are essential to create high-quality mosaic images from the acquired 3D datasets.
Photoelectrochemical hydrogen generation employing a Cu2O-based photocathode with improved stability and activity by using NixPy as the cocatalyst
Authors: Chhetri Manjeet , Rao C. N. R.
Published: May 2018

With the tactical integration of band edge energetics concepts in semiconducting films to reduce charge recombination and photocorrosion, an improvement in the photocurrent can be achieved by introducing CuO and NixPy into Cu2O films.
PAHs in toasted bread: determination using microwave-assisted extraction and dispersive liquid–liquid microextraction followed by high-performance liquid chromatography
Authors: Mahmoudpour Mansour , Pilevar Zahra , Javanmardi Fardin , Taram Faran , Mousavi Mir-Michael
Published: May 2018

In the present study, a fast, simple, and efficient method for the determination of PAHs in toasted bread was developed using microwave-assisted extraction (MAE) and dispersive liquid–liquid microextraction (DLLME) followed by high-performance liquid chromatography (HPLC).
Determination of the limits of detection for aluminum-based alloys by spatially resolved single- and double-pulse laser-induced breakdown spectroscopy
Authors: Sun Duixiong , Ma Yunyun , Wang Yongqiang , Su Maogen , Lu Quanfang , Dong Chenzhong
Published: May 2018

A comparative study of LIBS with spatially resolved single- and double-pulse configurations is performed to investigate the capability of simultaneous multi-element detection in aluminum-based alloys.
A visual detection of bisphenol A based on peroxidase-like activity of hemin–graphene composites and aptamer
Authors: Xiong Zhengwei , Zhong Haixia , Zheng Shuang , Deng Pengxi , Li Ning , Yun Wen , Yang Lizhu
Published: May 2018

Herein, a fast and visible colorimetric method for bisphenol A (BPA) detection was developed using hemin-functionalized reduced graphene oxide (H–rGO) composites and aptamer.
Ultrasonic-assisted preparation of a pinhole-free BiVO4 photoanode for enhanced photoelectrochemical water oxidation
Authors: Park Gisang , Park Joon Yong , Seo Jong Hyeok , Oh Kyung Hee , Ma Ahyeon , Nam Ki Min
Published: May 2018

A pinhole-free BiVO4 electrode showed highly improved photoelectrochemical activity for both sulfite oxidation and water oxidation.
Asymmetric synthesis of α-trifluoromethoxy ketones with a tetrasubstituted α-stereogenic centre via the palladium-catalyzed decarboxylative allylic alkylation of allyl enol carbonates
Authors: Kondo Hiroya , Maeno Mayaka , Hirano Kazuki , Shibata Norio
Published: May 2018

The Pd-catalyzed asymmetric decarboxylative allylic alkylation of trifluoromethoxy allyl enol carbonates is disclosed.
Revisiting the structural homogeneity of NU-1000, a Zr-based metal–organic framework
Authors: Islamoglu Timur , Otake Ken-ichi , Li Peng , Buru Cassandra T. , Peters Aaron W. , Akpinar Isil , Garibay Sergio J. , Farha Omar K.
Published: May 2018

Synthesis and activation of phase-pure and defect-free metal–organic frameworks (MOFs) are essential for establishing accurate structure–property relationships.
First-principles prediction of two-dimensional metal bis(dithiolene) complexes as promising gas sensors
Authors: Liu Hongmei , Li Xiaolong , Shi Changmin , Wang Dongchao , Chen Li , He Yuanyuan , Zhao Jianwei
Published: May 2018

The selective adsorption of NO molecules on Pd- and Pt-based 2D MOFs greatly enhances the conductivity.
Fabrication of zinc-dicarboxylate- and zinc-pyrazolate-carboxylate-framework thin films through vapour–solid deposition
Authors: Medishetty Raghavender , Zhang Zongji , Sadlo Alexander , Cwik Stefan , Peeters Daniel , Henke Sebastian , Mangayarkarasi Nagarathinam , Devi Anjana
Published: May 2018

Fabrication of 3-dimensional MOF thin films has been investigated through the conversion of ZnO thin film via a pure vapour–solid deposition reaction at ambient pressure.
Nitrogen-doped graphitic hierarchically porous carbon nanofibers obtained via bimetallic-coordination organic framework modification and their application in supercapacitors
Authors: Yao Yuechao , Liu Peng , Li Xiaoyan , Zeng Shaozhong , Lan Tongbin , Huang Haitao , Zeng Xierong , Zou Jizhao
Published: May 2018

Herein, N-doped graphitic hierarchically porous carbon nanofibers (NGHPCF) were prepared by electrospinning the composite of bimetallic-coordination metal–organic frameworks and polyacrylonitrile, followed by a pyrolysis and acid wash process.
A MOF-derived method to construct well-arranged porous nanosheets for lithium ion batteries
Authors: Du JinCheng , Tang YuHai , Wang Yu , Shi PengHui , Fan JinChen , Xu QunJie , Min YuLin
Published: May 2018

In this work, we report a facile route to fabricate a ZnCo2O4 nanosheet derived from metal–organic frameworks.
pH and molecular weight dependence of auric acid reduction by polyethylenimine and the gene transfection efficiency of cationic gold nanoparticles thereof
Authors: Cavuslar O. , Celaloglu C. , Duman F. D. , Konca Y. U. , Yagci M. B. , Yagci Acar H.
Published: May 2018

Small, cationic gold nanoparticles (GNPs) are produced by the direct reduction of auric acid in a non-reducing solvent, water, with branched polyethylenimine (bPEI) in a broad pH range (3.0–9.0).
Correction: Complex formation of nickel(ii) and zinc(ii) ions with peptide fragments of rat amylin
Authors: Dávid Ágnes , Hartman Éva Tünde , Lihi Norbert , Sóvágó Imre , Várnagy Katalin
Published: May 2018

Correction for ‘Complex formation of nickel(ii) and zinc(ii) ions with peptide fragments of rat amylin’ by Ágnes Dávid et al., New J. Chem., 2018, DOI: 10.1039/c7nj04605g.
Delivery of interleukin-22 binding protein (IL-22BP) gene by cationic micelle for colon cancer gene therapy
Authors: Men Ke , Huang Rong , Zhang Xueyan , Zhang Rui , Zhang Yuanfa , Peng Yao , Tong Rongsheng , Yang Li , Wei Yuquan , Duan Xingmei
Published: May 2018

Cationic DMP micelle delivered interleukin-22BP gene efficiently inhibits colon carcinoma growth, providing a novel strategy for cancer gene therapy.
Li+ conductivity of tungsten bronze LixSr1−0.5xTa2O6 studied by neutron diffraction analysis
Authors: Han Hyeon-Dong , Avdeev Maxim , Kim Young-Il
Published: May 2018

Based on the neutron Rietveld analysis, a three-dimensional Li+ conduction pathway is proposed for the tetragonal tungsten bronze lattice.
Direct impregnation of SeS2 into a MOF-derived 3D nanoporous Co–N–C architecture towards superior rechargeable lithium batteries
Authors: He Jiarui , Lv Weiqiang , Chen Yuanfu , Xiong Jie , Wen Kechun , Xu Chen , Zhang Wanli , Li Yanrong , Qin Wu , He Weidong
Published: May 2018

Metal–organic framework (MOF) derived cobalt- and nitrogen-doped porous carbon (Co–N–C) polyhedra are employed, for the first time, as SeS2 immobilizers (Co–N–C/SeS2).
Chronic exposure to acephate triggers ROS-mediated injuries at organismal and sub-organismal levels ofDrosophila melanogaster
Authors: Rajak Prem , Khatun Salma , Dutta Moumita , Mandi Moutushi , Roy Sumedha
Published: May 2018

The present study demonstrates ROS-mediated organismal and sub-organismal injuries inDrosophila melanogasterfollowing chronic acephate exposure.
Elements of Phonological Interventions for Children With Speech Sound Disorders: The Development of a Taxonomy
Authors: Baker Elise , Williams A. Lynn , McLeod Sharynne , McCauley Rebecca
Published: May 2018

Purpose

Our aim was to develop a taxonomy of elements comprising phonological interventions for children with speech sound disorders.

Method

We conducted a content analysis of 15 empirically supported phonological interventions to identify and describe intervention elements. Measures of element concentration, flexibility, and distinctiveness were used to compare and contrast interventions.

Results

Seventy-two intervention elements were identified using a content analysis of intervention descriptions then arranged to form the Phonological Intervention Taxonomy: a hierarchical framework comprising 4 domains, 15 categories, and 9 subcategories. Across interventions, mean element concentration (number of required or optional elements) was 45, with a range of 27 to 59 elements. Mean flexibility of interventions (percentage of elements considered optional out of all elements included in the intervention) was 44%, with a range of 29% to 62%. Distinctiveness of interventions (percentage of an intervention's rare elements and omitted common elements out of all elements included in the intervention [both optional and required]) ranged from 0% to 30%.

Conclusions

An understanding of the elements that comprise interventions and a taxonomy that describes their structural relationships can provide insight into similarities and differences between interventions, help in the identification of elements that drive treatment effects, and facilitate faithful implementation or intervention modification. Research is needed to distil active elements and identify strategies that best facilitate replication and implementation.
Applied Chaos Level Test for Validation of Signal Conditions Underlying Optimal Performance of Voice Classification Methods
Authors: Liu Boquan , Polce Evan , Sprott Julien C. , Jiang Jack J.
Published: May 2018

Purpose

The purpose of this study is to introduce a chaos level test to evaluate linear and nonlinear voice type classification method performances under varying signal chaos conditions without subjective impression.

Study Design

Voice signals were constructed with differing degrees of noise to model signal chaos. Within each noise power, 100 Monte Carlo experiments were applied to analyze the output of jitter, shimmer, correlation dimension, and spectrum convergence ratio. The computational output of the 4 classifiers was then plotted against signal chaos level to investigate the performance of these acoustic analysis methods under varying degrees of signal chaos.

Method

A diffusive behavior detection–based chaos level test was used to investigate the performances of different voice classification methods. Voice signals were constructed by varying the signal-to-noise ratio to establish differing signal chaos conditions.

Results

Chaos level increased sigmoidally with increasing noise power. Jitter and shimmer performed optimally when the chaos level was less than or equal to 0.01, whereas correlation dimension was capable of analyzing signals with chaos levels of less than or equal to 0.0179. Spectrum convergence ratio demonstrated proficiency in analyzing voice signals with all chaos levels investigated in this study.

Conclusion

The results of this study corroborate the performance relationships observed in previous studies and, therefore, demonstrate the validity of the validation test method. The presented chaos level validation test could be broadly utilized to evaluate acoustic analysis methods and establish the most appropriate methodology for objective voice analysis in clinical practice.
Efficient unitary matrix pencil method for synthesising wideband frequency patterns of sparse linear arrays
Authors: Gu Pengfei , Wang Gui , Fan Zhenhong , Chen Rushan
Published: May 2018

A novel technique incorporating the unitary matrix pencil (UMP) method is extended to the case of sparse linear arrays with wideband frequency invariant (FI) patterns. Multiple pattern data at different frequencies are formulated with the same poles corresponding to the FI element positions by a new sampling strategy. The unitary transform converts the complex computations for block Hankel matrices into real ones, which contributes to the reduction of the computation complexity for the singular value decomposition and the eigenvalue decomposition procedures. Taking advantage of the equivalent matrix pencil obtained by the unitary transformation, a new relation between the element positions and generalised eigenvalues can be built by the UMP method, which contributes to the real solutions for all element positions win wideband. A new tactics is exploited to avoid small element spacing with the consideration of the size of array antennas. Multiple FI patterns are reconstructed with a higher matching accuracy by only varying the excitation distributions. A set of representative numerical examples demonstrate the efficiency and advantages of the proposed method.
Capacitor static voltage balance based on auxiliary‐power supply pulse width control for MMC
Authors: Luo Longfei , Zhang Yanbin , Jia Lixin , Yang Ningning , Yang Lixia , Zhang Huihui
Published: May 2018

As one of the most potential converter topologies, modular multilevel converter (MMC) is widely used in high‐voltage direct current (HVDC) transmission systems. The capacitor static voltage imbalance during HVDC system start‐up stage has become a key issue. This study presents a new capacitor static voltage balance method based on auxiliary‐power supply (APS) pulse width control for MMC. The control signal of APS can be generated by comparing the modulation signal for voltage closed‐loop control with the carrier signal with fixed frequency. An AND gate circuit is used to improve the APS Metal oxide semiconductor (MOS) driving circuits. Based on these circuits, the input current of APS can be regulated, and the capacitor voltage can be controlled. Since only the inherent sub‐module (SM) APS is needed in this method, it has low hardware costs. The control strategy in this method is simple, and it has no restrictions on the SM number. This determines that the presented method has a wider range of application. Furthermore, the value of equalising resistor is increased, and the losses of SM and MMC are reduced in this method. Experimental results from the laboratory prototype verify the effectiveness of the presented method.
The circumstellar environment of HD 50138 revealed by VLTI/AMBER at high angular resolution
Authors: Koutoulaki M. , Garcia Lopez R. , Natta A. , Caratti o Garatti A. , Coffey D. , Sanchez-Bermudez J. , Ray T. P.
Published: May 2018

Context. HD 50138 is a Herbig B[e] star with a circumstellar disc detected at infrared and millimeter wavelength. Its brightness makes it a good candidate for near-infrared interferometry observations.

Aims. We aim to resolve, spatially and spectrally, the continuum and hydrogen emission lines in the 2.12–2.47 micron region, to shed light on the immediate circumstellar environment of the star.

Methods. VLTI/AMBER K-band observations provide spectra, visibilities, differential phases, and closure phases along three long baselines for the continuum, and H I emission in Brγ and five high-n Pfund lines. By computing the pure line visibilities, we derive the angular size of the different line-emitting regions. A simple local thermodynamic equilibrium (LTE) model was created to constrain the physical conditions of H I emitting region.

Results. The continuum region cannot be reproduced by a geometrical two-dimensional (2D) elongated Gaussian fitting model. We estimate the size of the region to be 1 au. We find the detected hydrogen lines (Brγ and Pfund lines) come from a more compact region of size 0.4 au. The Brγ line exhibits an S-shaped differential phase, indicative of rotation. The continuum and Brγ line closure phases show offsets of ~ −25 ± 5° and 20 ± 10° respectively. This is evidence of an asymmetry in their origin, but with opposing directions. We find that we cannot converge on constraints for the HI physical parameters without a more detailed model.

Conclusions. Our analysis reveals that HD 50138 hosts a complex circumstellar environment. Its continuum emission cannot be reproduced by a simple disc brightness distribution. Similarly, several components must be evoked to reproduce the interferometric observables within the Brγ line. Combining the spectroscopic and interferometric data of the Brγ and Pfund lines favours an origin in a wind region with a large opening angle. Finally, although we cannot exclude the possibility that HD 50138 is a young star our results point to an evolved source.
Gestion orthodontique de l’inclusion horizontale des incisives maxillaires : à propos d’un cas clinique
Authors: Ben Aissa H. , Dallel I. , Sediri D. , Tobji S. , Ben Amor A. , Ben Amor F.
Published: May 2018

L’inclusion horizontale des incisives maxillaires présente sans aucun doute un préjudice esthétique et fonctionnel important. Elle pose des difficultés de diagnostic, d’où l’intérêt du cone beam comme, d’une part, un excellent moyen de diagnostic et un guide thérapeutique et, d’autre part, une aide à la décision entre la traction orthodontique ou l’extraction et la réhabilitation prothétique. De ce fait, la mise en occlusion des incisives incluses en position horizontale constitue un défi pour l’orthodontiste.

Dans ce travail, nous présentons un cas clinique où nous avons pu tracter deux incisives maxillaires incluses.
Une approche originale du sens transversal en technique linguale
Authors: Bernard-Granger C. , Filippi R. , Cresseaux P.
Published: May 2018

La gestion du sens transversal est essentielle pour la réussite de nos traitements orthodontiques. Elle est conditionnée au choix du bon plan de traitement et des techniques mécaniques les plus simples.

Lorsque l’insuffisance transversale est associée à d’autres dysmorphoses chez l’adulte, le praticien doit faire le choix entre un traitement chirurgical en une ou en deux phases par chirurgie primaire d’expansion.

De plus, si le patient bénéficie d’un traitement orthodontico-chirurgical avec multi-attache lingual, les moyens d’expansion et de stabilisation de l’expansion sont peu évidents techniquement.

L’objet de cet article est de présenter le cas d’un patient adulte avec insuffisance maxillaire associée à une classe III sur schéma hyperdivergent. Il est traité par une méthode orthodontico-chirurgicale en une phase. Au maxillaire, un multi-attache lingual associé à un disjoncteur FKS® a permis une expansion fiable et simple techniquement.
Tempêtes hivernales des latitudes tempérées : théories et prévisions
Authors: Rivière Gwendal , Arbogast Philippe
Published: May 2018

De nombreuses zones d’ombre demeurent encore sur notre connaissance de la dynamique des tempêtes hivernales, et ce, malgré une demande sociétale toujours accrue pour améliorer leur prévision à courte échéance ou encore pour estimer leur évolution dans le climat futur.

L’article commence par une explication du mécanisme principal permettant le développement d’une tempête, et par un rappel des caractéristiques des dernières tempêtes ayant touché la France. Dans une seconde partie, on présente les problèmes de prévisibilité liés aux incertitudes sur les conditions initiales, et les différentes stratégies employées par les centres opérationnels de prévision du temps pour prendre en compte ces incertitudes.
La lumière au bout du tunnel, ou comment concentrer et séparer des microalgues en combinant lumière et écoulement
Authors: Rafaï Salima , Peyla Philippe
Published: May 2018

La microalgue verte Chlamydomonas reinhardtii (Chlamy) est capable de se déplacer au sein de son environnement liquide à l’aide de ses deux flagelles. Chlamy possède un « stigma » – l’oeil le plus simple du monde biologique – qui lui permet d’être phototactique, c’est-à-dire de pouvoir se diriger vers une source lumineuse.

Nous décrirons ici le phénomène de photofocalisation par lequel, grâce à un écoulement et de la lumière, les microalgues sont amenées à se concentrer spontanément au centre d'un canal. En outre, nous montrerons comment les propriétés de ce micronageur peuvent être généralisées à d’autres systèmes et ainsi contribuer à une compréhension plus globale des écoulements de matière active.
Matière active synthétique
Authors: Bartolo Denis , Cottin-Bizonne Cécile
Published: May 2018

Ces dix dernières années, la maîtrise des propriétés interfaciales d’objets micrométriques a permis la motorisation de robots colloïdaux, notamment par propulsion électrique ou électrochimique. Ces micronageurs artificiels se sont révélés capables de s’auto-organiser en de nouvelles classes de matériaux aux propriétés inattendues. Dans cet article, nous décrivons l’organisation originale de deux types de particules colloïdales autopropulsées : des colloïdes Janus non-attractifs exhibant un comportement collectif de type adhésif, et des colloïdes rouleurs (dits de Quincke) qui s’assemblent en des fluides que l’on ne peut empêcher de s’écouler.