bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimising treatment strategies for ADHD in adolescence to minimise ‘lost in transition’ to adulthood
Authors: Buitelaar J. K.
Published: April 2017

The persistence of attention-deficit hyperactivity disorder (ADHD) from adolescence to adulthood is not matched by continuity of care in this transition period. Many adolescents with ADHD have poor medication adherence or even stop medication treatment, and use of behavioural interventions is also suboptimal. The present commentary focuses on treatment strategies that might improve effects of ADHD medication treatment by improving adherence in adolescents with ADHD and/or optimise behavioural interventions for ADHD in adolescence. Most treatment strategies in adolescents with ADHD are merely copied from treatments offered to children. Instead however treatment should be focused on what makes adolescents special and vulnerable, such as poor insight into own functioning and poor decision making. Techniques that offer promise for adolescents are motivational interviewing, use of ecological momentary assessments and interventions, mindfulness-based training and serious games. Systematic studies into the effects of these techniques alone and in combination with medication are lacking.
Behavioral Parent Training Groups for ADHD in Clinical Settings: Does Offering a Concurrent Child Group Add Value?
Authors: Loren Richard E. A. , Ciesielski Heather A. , Tamm Leanne
Published: April 2017

There is strong evidence for the efficacy of behavioral parent training (BPT) for attention deficit/hyperactivity disorder (ADHD). However, BPT can be difficult to access in many communities, which may be due to practical considerations including whether to offer concurrent child groups. Few studies have specifically examined whether concurrent child treatment is beneficial for ADHD—particularly in real-world clinical settings (i.e., not in a formal research context). Concurrent child groups may improve adherence as they address a practical barrier to attendance, and may boost treatment outcomes given the additional treatment provided directly to children. However, this should be empirically verified given that offering concurrent child treatment poses a number of practical and costly challenges (e.g., extra staff, extra space) that are not recouped by insurance reimbursement. This preliminary study explores whether offering concurrent child treatment groups provides added treatment benefits in a sample of convenience obtained from an outpatient clinic. Data was collected from 241 parents of 6- to 12-year-old children with ADHD who attended 1 of 37 8-session BPT groups, of which 15 offered a concurrent child group. Parents completed ratings of child impairment and parenting confidence at the first and last BPT session. Results showed that clinical improvement was equitable regardless of whether a concurrent child group was attended, and there were no demographic or clinical differences between those who opted to attend the parent+child groups and those who did not. Suggestions are provided for clinicians who may decide to discontinue offering concurrent child groups.
Inhibition of DNA2 nuclease as a therapeutic strategy targeting replication stress in cancer cells
Authors: Kumar S , Peng X , Daley J , Yang L , Shen J , Nguyen N , Bae G , Niu H , Peng Y , Hsieh H-J , Wang L , Rao C , Stephan C C , Sung P , Ira G , Peng G
Published: April 2017

Replication stress is a characteristic feature of cancer cells, which is resulted from sustained proliferative signaling induced by activation of oncogenes or loss of tumor suppressors. In cancer cells, oncogene-induced replication stress manifests as replication-associated lesions, predominantly double-strand DNA breaks (DSBs). An essential mechanism utilized by cells to repair replication-associated DSBs is homologous recombination (HR). In order to overcome replication stress and survive, cancer cells often require enhanced HR repair capacity. Therefore, the key link between HR repair and cellular tolerance to replication-associated DSBs provides us with a mechanistic rationale for exploiting synthetic lethality between HR repair inhibition and replication stress. DNA2 nuclease is an evolutionarily conserved essential enzyme in replication and HR repair. Here we demonstrate that DNA2 is overexpressed in pancreatic cancers, one of the deadliest and more aggressive forms of human cancers, where mutations in the KRAS are present in 90–95% of cases. In addition, depletion of DNA2 significantly reduces pancreatic cancer cell survival and xenograft tumor growth, suggesting the therapeutic potential of DNA2 inhibition. Finally, we develop a robust high-throughput biochemistry assay to screen for inhibitors of the DNA2 nuclease activity. The top inhibitors were shown to be efficacious against both yeast Dna2 and human DNA2. Treatment of cancer cells with DNA2 inhibitors recapitulates phenotypes observed upon DNA2 depletion, including decreased DNA double strand break end resection and attenuation of HR repair. Similar to genetic ablation of DNA2, chemical inhibition of DNA2 selectively attenuates the growth of various cancer cells with oncogene-induced replication stress. Taken together, our findings open a new avenue to develop a new class of anticancer drugs by targeting druggable nuclease DNA2. We propose DNA2 inhibition as new strategy in cancer therapy by targeting replication stress, a molecular property of cancer cells that is acquired as a result of oncogene activation instead of targeting currently undruggable oncoprotein itself such as KRAS.
Erratum: MiR-186 inhibited aerobic glycolysis in gastric cancer via HIF-1α regulation
Authors: Liu L , Wang Y , Bai R , Yang K , Tian Z
Published: April 2017

Correction to: Oncogenesis (2016) 5, e224; doi:10.1038/oncsis.2016.35; published online 9 May 2016 Since the publication of the above article, the authors have realized that both Figure 2c, apoptosis figure of Agomir-186-NC group of SGC7901 cell, and Figure 4c, apoptosis figure of Antagomir-186+shHIF-1α, were wrongly used.
p16 controls epithelial cell growth and suppresses carcinogenesis through mechanisms that do not require RB1 function
Authors: Sen M , Akeno N , Reece A , Miller A L , Simpson D S , Wikenheiser-Brokamp K A
Published: April 2017

The p16/RB1 tumor suppressor pathway is inactivated in the vast majority, if not all, human cancers. The current paradigm is that p16 and RB1 function in a linear pathway to suppress tumorigenesis; however p16 is preferentially lost in human cancers suggesting that p16 has critical tumor suppressive functions not mediated through RB1. Carcinomas arise from transformed epithelial cells and account for 80% of adult malignancies highlighting the need to understand p16/RB1 pathway function in organ epithelia. Lung cancer is the leading cause of cancer deaths and is associated with p16/RB1 pathway deregulation. We demonstrate that p16 is upregulated in the lung epithelium after Rb1 ablation in genetically engineered mouse models. In contrast to fibroblasts, loss of RB1 family proteins, p107 or p130, did not result in p16 induction, demonstrating that p16 suppression is a unique RB1 pocket protein function in the lung epithelium in vivo. p16 upregulation did not induce cellular senescence but rather promoted survival of RB1-deficient lung epithelial progenitor cells. Mechanistic studies show that p16 protects RB1-deficient cells from DNA damage. Consequently, additional loss of p16 led to genetic instability and increased susceptibility to cellular immortalization and transformation. Mice with combined RB1/p16-deficient lungs developed lung tumors including aggressive metastatic lung cancers. These studies identify p16 loss as a molecular event that causes genetic instability and directly demonstrate that p16 protects against DNA damage in the absence of RB1 function providing an explanation for why p16 is preferentially targeted in human cancers.
Opposing activities of oncogenic MIR17HG and tumor suppressive MIR100HG clusters and their gene targets regulate replicative senescence in human adult stem cells
Authors: Lopez Mary F. , Niu Ping , Wang Lu , Vogelsang Maryann , Gaur Meenakshi , Krastins Bryan , Zhao Yueqiang , Smagul Aibek , Nussupbekova Aliya , Akanov Aikan A. , Jordan I. King , Lunyak Victoria V.
Published: April 2017

Growing evidence suggests that many diseases of aging, including diseases associated with robust changes and adipose deports, may be caused by resident adult stem cell exhaustion due to the process called cellular senescence. Understanding how microRNA pathways can regulate cellular senescence is crucial for the development of novel diagnostic and therapeutic strategies to combat these pathologies. Herein, using integrated transcriptomic and semi-quantitative proteomic analysis, we provide a system level view of the regulation of human adipose-derived stem cell senescence by a subset of mature microRNAs (termed senescence-associated-microRNAs) produced by biogenesis of oncogenic MIR17HG and tumor-suppressive MIR100HG clusters. We demonstrate functional significance of these mature senescence-associated-microRNAs in the process of replicative senescence of human adipose-derived stem cells ex-vivo and define a set of senescence-associated-microRNA gene targets that are able to elicit, modulate and, most importantly, balance intimate connections between oncogenic and senescent events.
Extremely bulky copper(i) complexes of [HB(3,5-{1-naphthyl}2pz)3]− and [HB(3,5-{2-naphthyl}2pz)3]− and their self-assembly on graphene
Authors: van Dijkman Thomas F. , de Bruijn Hans M. , Brevé Tobias G. , van Meijeren Bob , Siegler Maxime A. , Bouwman Elisabeth
Published: April 2017

Self-assembled thin layers of copper(i) carbonyl complexes of naphthyl-substituted pyrazolylborate ligands coated onto graphene were studied by AFM and STM.
Prebiotics increase heme iron bioavailability and do not affect non-heme iron bioavailability in humans
Authors: Weinborn Valerie , Valenzuela Carolina , Olivares Manuel , Arredondo Miguel , Weill Ricardo , Pizarro Fernando
Published: April 2017

The aim of this study was to establish the effect of a prebiotic mix on iron bioavailability.
Detection of herbicide glyphosates based on an anti-aggregation mechanism by using unmodified gold nanoparticles in the presence of Pb2+
Authors: Zhou Zhuangwei , Zhang Yujie , Kang Jingyan , Dong Chen , Chen Ningyi , Li Xing , Guo Zhiyong , Wu Aiguo
Published: April 2017

The AuNP-based colorimetric sensor can be used for the rapid detection of glyphosate with excellent selectivity and sensitivity in real environmental water, based on an anti-aggregation mechanism.
A simplified approach in flow controlled multi-dimensional gas chromatography
Authors: Luong J. , Gras R. , Shellie R. A.
Published: April 2017

We introduce a simple and reliable approach for practicing flow controlled multi-dimensional gas chromatography.
Fabrication of a novel hollow fiber membrane decorated with functionalized Fe2O3 nanoparticles: towards sustainable water treatment and biofouling control
Authors: Hebbar Raghavendra S. , Isloor Arun M. , Ananda K. , Abdullah Mohd. Sohaimi , Ismail A. F.
Published: April 2017

We explored a new strategy using well dispersed functionalized Fe2O3 nanoparticles to fabricate a polyetherimide nanocomposite hollow fiber membrane with enhanced surface and anti-biofouling properties.
Facile synthesis of 3D hierarchical MnO2 microspheres and their ultrahigh removal capacity for organic pollutants
Authors: Khalid Syed , Cao Chuanbao
Published: April 2017

The weight ratio of degraded MB to catalyst (40 mg mg−1) is much higher than most reported values.
DNA and BSA binding and cytotoxic properties of copper(ii) and iron(iii) complexes with arylhydrazone of ethyl 2-cyanoacetate or formazan ligands
Authors: Martins Nuno M. R. , Anbu Sellamuthu , Mahmudov Kamran T. , Ravishankaran Rajendran , Guedes da Silva M. Fátima C. , Martins Luísa M. D. R. S. , Karande Anjali A. , Pombeiro Armando J. L.
Published: April 2017

Copper(ii) and iron(iii) complexes with arylhydrazone of ethyl 2-cyanoacetate or formazan ligands show DNA and BSA binding and anticancer abilities.
A new thermoresponsive polymer of poly(N-acryloylsarcosine methyl ester) with a tunable LCST
Authors: Chen Shengli , Wang Ke , Zhang Wangqing
Published: April 2017

A thermoresponsive polymer of the tertiary amide-based polyacrylamide, PNASME, was synthesized and its tunable thermoresponse was investigated.
Two novel supramolecular metallogels constructed by platinum(ii) coordination and pillar[5]arene-based host–guest interactions
Authors: Li Zhengtao , Xing Hao , Shi Bingbing
Published: April 2017

Two multi-responsive supramolecular metallogels were constructed by coordination-driven self-assembly, host–guest interaction and supramolecular polymerization.
Polymerization induced self-assembly: tuning of morphology using ionic strength and pH
Authors: Zhou Dewen , Dong Siming , Kuchel Rhiannon P. , Perrier Sebastien , Zetterlund Per B.
Published: April 2017

It is demonstrated how the morphology of polymeric nanoparticles produced via polymerization-induced self-assembly (PISA) in dispersion can be conveniently tuned via the pH and ionic strength.
Controlled synthesis of highly active Au/CeO2 nanotubes for CO oxidation
Authors: Wang Zumin , Qi Jian , Zhao Kun , Zong Lingbo , Tang Zhiyong , Wang Lianzhou , Yu Ranbo
Published: April 2017

High-quality Au/CeO2 nanotubes were synthesized through an oriented attachment-Ostwald ripening process and they showed excellent performance in catalytic CO oxidation.
Fine cophasing of segmented aperture telescopes with ZELDA, a Zernike wavefront sensor in the diffraction-limited regime
Authors: Janin-Potiron P. , N’Diaye M. , Martinez P. , Vigan A. , Dohlen K. , Carbillet M.
Published: April 2017

Context. Segmented aperture telescopes require an alignment procedure with successive steps from coarse alignment to monitoring process in order to provide very high optical quality images for stringent science operations such as exoplanet imaging. The final step, referred to as fine phasing, calls for a high sensitivity wavefront sensing and control system in a diffraction-limited regime to achieve segment alignment with nanometric accuracy. In this context, Zernike wavefront sensors represent promising options for such a calibration. A concept called the Zernike unit for segment phasing (ZEUS) was previously developed for ground-based applications to operate under seeing-limited images. Such a concept is, however, not suitable for fine cophasing with diffraction-limited images.

Aims. We revisit ZELDA, a Zernike sensor that was developed for the measurement of residual aberrations in exoplanet direct imagers, to measure segment piston, tip, and tilt in the diffraction-limited regime.

Methods. We introduce a novel analysis scheme of the sensor signal that relies on piston, tip, and tilt estimators for each segment, and provide probabilistic insights to predict the success of a closed-loop correction as a function of the initial wavefront error.

Results. The sensor unambiguously and simultaneously retrieves segment piston and tip-tilt misalignment. Our scheme allows for correction of these errors in closed-loop operation down to nearly zero residuals in a few iterations. This sensor also shows low sensitivity to misalignment of its parts and high ability for operation with a relatively bright natural guide star.

Conclusions. Our cophasing sensor relies on existing mask technologies that make the concept already available for segmented apertures in future space missions.
Meningioma of the Fourth Ventricle: Literature Review
Authors: Polverini Allan Dias , Sola Rodrigo de Almeida Simon , Bortoluzzi Guilherme Fonseca , Lombardi Ismael Augusto Silva , Picone Junior Giusepe , de Almeida Junior Carlos Roberto , Clara Carlos Afonso
Published: April 2017

Meningiomas are among the most common central nervous system tumors, with an incidence that ranges from 15% to 40% of intracranial tumors. Of these, only 0.5% to 3% are intraventricular, and the rarest of them occurs in the fourth ventricle.

Fourth-ventricle meningiomas originate generally from the choroid plexus and have no dural adhesions. Most often, they manifest in young patients, around 41 years of age, with a possible predominance in females, through intracranial hypertension and cerebellar syndromes. The treatment consists of surgical resection, which commonly presents good results due to the characteristics of the tumor. So, for better preoperative planning, the radiological differentiation of the most frequent tumors in this location is important.

The most common histologic subtypes are fibroblastic and meningothelial, both grade I according to the World Health Organization (WHO), although there are reports of tumors of grades II and III.

We report a case of meningioma of the fourth ventricle operated in our institution, and we have conducted a literature review, through which we found that 57 cases have been reported so far, with the first one reported in 1938.
Efficiency loss of thin film Cu(InxGa1−x)Se(S) solar panels by lamination process
Authors: Xu Li
Published: April 2017

Efficiency loss of thin film Cu(InxGa1−x)Se(S) (CIGS) solar panels by lamination process has been compromising the final output power in commercial products of solar modules, but few reports have been published on such issue, as the majority of the investigation is focused on the efficiency at the circuit level, i.e., before lamination process. In this paper, we studied the effect of lamination process to the efficiency loss of thin film CIGS solar panels. It was observed that the fill factor degradation dominated the efficiency loss with the small change of Voc and Jsc. Experiments showed that neither the temperature nor the pressure, nor the two combined in the lamination process is the root cause of the efficiency loss; instead, the ethylene vinyl acetate (EVA) layer as the encapsulation material which directly contacts the solar cell devices was the major factor responsible for the efficiency loss. It was found that the gel content of the cured EVA film after lamination was highly correlated to the efficiency loss. The higher the gel content, the higher the efficiency loss. The mismatch of coefficient of thermal expansion between the EVA film and the CIGS thin film resulted in compressive stress in the device layer after lamination process. The compressive stress is speculated to affect the lattice defects, but need to be confirmed with the measurement of capacitance voltage (CV) and drive level capacitance profiling (DLCP). Three-day sun soak was then carried out and it was observed that the fill factor recovered significantly and so did the efficiency. Experiments also showed that there was no impact of chemical erosion on the front electrode of transparent conductive oxide (TCO) films by chemicals released from the EVA films during lamination.
A microscopic mechanism of dielectric breakdown in SiO2 films: An insight from multi-scale modeling
Authors: Padovani A. , Gao D. Z. , Shluger A. L. , Larcher L.
Published: April 2017

Despite extensive experimental and theoretical studies, the atomistic mechanisms responsible for dielectric breakdown (BD) in amorphous (a)-SiO2 are still poorly understood. A number of qualitative physical models and mathematical formulations have been proposed over the years to explain experimentally observable statistical trends. However, these models do not provide clear insight into the physical origins of the BD process. Here, we investigate the physical mechanisms responsible for dielectric breakdown in a-SiO2 using a multi-scale approach where the energetic parameters derived from a microscopic mechanism are used to predict the macroscopic degradation parameters of BD, i.e., time-dependent dielectric breakdown (TDDB) statistics, and its voltage dependence. Using this modeling framework, we demonstrate that trapping of two electrons at intrinsic structural precursors in a-SiO2 is responsible for a significant reduction of the activation energy for Si-O bond breaking. This results in a lower barrier for the formation of O vacancies and allows us to explain quantitatively the TDDB data reported in the literature for relatively thin (3–9 nm) a-SiO2 oxide films.
New Products
Authors: Mandelis Andreas
Published: April 2017

In order to supplement manufacturers’ information, this Department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials which supersede earlier data or suggest new research applications.
Spontaneous beating and synchronization of extensile active filament
Authors: Sarkar Debarati , Thakur Snigdha
Published: April 2017

We simulate a semi-flexible active filament that exhibits spontaneous oscillations on clamping and show self-propulsion when left free. The activity on the filament relies on the nano-dimers distributed at regular intervals along the chain. With an emphasis on the spontaneous beating of a clamped filament, we demonstrate that the two competing forces necessary for oscillation are the elastic forces due to polymer rigidity and the active forces due to chemical activity. In addition, we also study the synchronization of two extensile filaments and the role played by non-local hydrodynamic interactions. We observe a phase lock scenario between the filaments during their synchronous motion.
Effects of Cr-doping on the adsorption and dissociation of S, SO, and SO2 on Ni(111) surfaces
Authors: Das Nishith K. , Saidi Wissam A.
Published: April 2017

Nickel-based alloys are widely applied materials in high-temperature applications because they exhibit superior corrosion resistance and mechanical properties. The effects of sulfur, which is invariably present in industrial atmospheres, on the early stages of oxidation of Ni-based surfaces are not well understood. Here we use density functional theory to investigate the interactions of sulfur, SO, and SO2 with the Ni(111) and Cr-doped Ni(111) surface and elucidate their electronic interactions and potential energy surfaces. The results show that Cr doping of the Ni(111) surface increases the adsorption energies of sulfur, oxygen on the sulfur pre-adsorbed condition, SO and SO2. Further, this increase positively correlates with Cr concentration on top of the Ni(111) surface, although sulfur does not have any preferential interaction with Cr. This explains why Cr doping has little effect on the activation energy of sulfur for the most preferable diffusion path. Nevertheless, the increase in adsorption energies indicates a strong interaction with Cr-doped surfaces, which is due to the Cr-enhanced charge transfer to sulfur adsorbates. The existence of pre-adsorbed sulfur is shown to have a destabilizing effect on the oxygen interactions with the surfaces. Our results show that Cr doping helps to stabilize the protective oxide scale on Ni(111) surfaces and enhances its corrosion resistance.
The role of graphene in enhancing electrical heating and mechanical performances of graphene−aligned silver nanowire hybrid transparent heaters
Authors: Li P. , Ma J. G. , Xu H. Y. , Zhu H. C. , Liu Y. C.
Published: April 2017

In this work, flexible and energy-efficient transparent heaters based on graphene and aligned silver nanowire (G–ASNW) hybrid structures are fabricated by thermal evaporation of silver on the aligned electrospun nanofiber templates and subsequent transfer of monolayer graphene onto the ASNWs. The G–ASNW films exhibit few wire-wire junctions and low resistance along the aligned direction, which are favorable for low-voltage transparent heater applications. Coating the ASNW network with monolayer graphene increases the saturated temperature of the hybrid heater due to the high thermal conductivity and low convective heat-transfer coefficient of graphene. Meanwhile, G–ASNW films show excellent electromechanical stability under cyclic bending because the graphene anchoring on the top surface of ASNWs could share tensile stress and serve as local conducting pathways at break-points even if small cracks were generated. The G–ASNW hybrid structures present a perspective on wearable transparent heaters.
Ultrafast all-optical modulation in Fe-doped GaN at 1.31 and 1.55 μm with high contrast and ultralow power
Authors: Fang Yu , Yang Junyi , Xiao Zhengguo , Zhang Jiayong , Chen Yongqiang , Wu Quanying , Song Yinglin
Published: April 2017

We demonstrate the possibility of all-optical modulation at 1.31 and 1.55 μm optical communication wavelengths by interband pumping of Fe-doped GaN crystals using femtosecond pump-probe techniques. Considering the lower photon energy of near-infrared probe pulses, switching time was well controlled by Fe doping from the nanosecond range to a value as fast as 10 ps for Fe concentration of 1 × 1019 cm−3 arising from the carrier trapping effect of deep Fe acceptors, which suggests a modulation speed performance of ∼50 GHz. Simultaneously, about 50% of modulation contrast was achieved by means of optical excitation at an ultralow pump fluence of 0.5 mJ/cm2. Moreover, almost no degradation of the modulation contrast and speed was observed due to Fe doping.
Cathodo-luminescence of color centers induced in sapphire and yttria-stabilized zirconia by high-energy electrons
Authors: Costantini Jean-Marc , Watanabe Yasushi , Yasuda Kazuhiro , Fasoli Mauro
Published: April 2017

We have studied the color-center production in sapphire and yttria-stabilized zirconia (YSZ) single crystals by cathodo-luminescence (CL) spectroscopy for electron energies ranging between 400 and 1250 keV in a high-voltage electron microscope. Emission spectra were collected for in-beam conditions near room temperature and at 200 K. Comparison was made with CL spectra recorded for 3-keV–20-keV electrons in a scanning electron microscope. For high-energy electrons, CL spectra for sapphire revealed broad emission bands centered at photon energies about 3.0 eV and 3.8 eV that were, respectively, assigned to oxygen vacancies (F0 and F+ centers) induced by elastic collisions, on the basis of photoluminescence (PL) data. No such bands were recorded for 3-keV and 5-keV electrons. Two similar bands were also recorded for YSZ (with 9.5 and 18 mol. % yttria) at about 2.8 eV and 4.1 eV that can be, respectively, attributed to the native oxygen vacancies (F2+ centers) and F+ centers. The 4.1-eV band was not seen for 20-keV electrons: it was only produced for high electron energies by elastic collision processes. Instead, the small side band was also found at 2.85 eV for 20-keV electrons. PL excitation contour plots of virgin and irradiated YSZ were also recorded to support our discussion on point-defect identification. CL band intensities show a maximum versus electron energy, whereas point-defect concentrations should increase due to the increase of oxygen atom displacement cross section. The effect of electron energy on the different steps of the CL process is discussed to account for such a behavior.
Parasitic channel induced by an on-state stress in AlInN/GaN HEMTs
Authors: Petitdidier S. , Guhel Y. , Trolet J. L. , Mary P. , Gaquière C. , Boudart B.
Published: April 2017

In this paper, we have highlighted that an on-state stress can induce a parasitic channel in AlInN/GaN HEMTs. The devices have been stressed during 216 h with a drain-to-source voltage (VDS) of 20 V and a gate-to-source voltage (VGS) of 0 V. A decrease in the drain current (IDS max) of 43%, an increase in the access resistance (RON) of 100%, and a drop in the maximum extrinsic transconductance (gm max) from 234 mS/mm down to 144 mS/mm have been observed after the ageing test. Moreover, a double peak feature is shown in the gm (VGS) characteristic 4 months after the end of the on-state stress. Consequently, we can conclude that a parasitic channel has been created by the on-state stress in the AlInN/GaN transistors. At the same time, no degradation of the Schottky contact has been highlighted after the ageing test.
Interplay between deoxidation and dewetting for ultrathin SOI films
Authors: Trautmann M. , Cheynis F. , Leroy F. , Curiotto S. , Müller P.
Published: April 2017

Solid state dewetting of thin films is a promising method for producing nanodots. However, while films with submicron thicknesses simply breakup into arrays of dots, ultrathin films tend to form more complex dendritic structures. In this paper, we investigate the dewetting properties of ultrathin Silicon-on-Insulator samples capped by a chemically prepared oxide layer. We unambiguously show that the formation of a dendritic structure characteristic of Si(100) films thinner than ≈6 nm is due to an interplay between deoxidation and dewetting. For thicker films, the deoxidation is observed at lower temperature than the dewetting and thus does not influence the dewetting whereas for the thinner films, both phenomena occur simultaneously. In this case, the dewetted morphology results from the coalescence of voids in the Si(100) film that are limited by the thermal decomposition of the oxide cap.
Modulational instability of ion acoustic waves in a multi-species collisionless unmagnetized plasma consisting of nonthermal and isothermal electrons
Authors: Dalui Sandip , Bandyopadhyay Anup , Das K. P.
Published: April 2017

A nonlinear Schrödinger equation is derived to study the modulational instability of finite amplitude ion acoustic waves in a collisionless unmagnetized plasma consisting of warm adiabatic ions and two distinct populations of electrons, one is due to distributed energetic electrons described by Cairns et al. [Geophys. Res. Lett. 22, 2709 (1995)] which generates the energetic electrons, and the other is the isothermal electrons. The instability condition and the maximum growth rate of instability have been investigated numerically. We have studied the effect of each parameter of the present plasma system on the maximum growth rate of instability. In particular, it is found that the maximum growth rate of instability increases with the increasing values of the wave number for any given set of values of the parameters associated with the present plasma system. It has also been shown that for any fixed value of the wave number, the maximum growth rate of instability increases with increasing values of the nonthermal parameter associated with the Cairns distributed energetic electrons.
Probing the surface potential of oxidized silicon by assessing terahertz emission
Authors: Mochizuki Toshimitsu , Ito Akira , Mitchell Jonathon , Nakanishi Hidetoshi , Tanahashi Katsuto , Kawayama Iwao , Tonouchi Masayoshi , Shirasawa Katsuhiko , Takato Hidetaka
Published: April 2017

Using laser terahertz emission microscopy, we measured laser-excited terahertz (THz) emission from silicon wafers with silicon-oxide passivation layers, revealing a strong correlation between the THz waveform and the surface potential. The surface potential was electrically tuned by a semitransparent top electrode disc and evaluated by measuring capacitance–voltage characteristics. The waveform changed with external bias and inverted near the flatband voltage, and changes appeared in the peak amplitude were similar to the capacitance–voltage characteristics. These results indicate that by analyzing the waveform of laser-excited THz emission generated by laser terahertz emission microscopy, we could quantitatively measure and map the internal field of surface band bending in semiconductors.
A novel technique based on a plasma focus device for nano-porous gallium nitride formation on P-type silicon
Authors: Sharifi Malvajerdi S. , Salar Elahi A. , Habibi M.
Published: April 2017

A new deposition formation was observed with a Mather-type Plasma Focus Device (MPFD). MPFD was unitized to fabricate porous Gallium Nitride (GaN) on p-type Silicon (Si) substrate with a (100) crystal orientation for the first time in a deposition process. GaN was deposited on Si with 4 and 7 shots. The samples were subjected to a 3 phase annealing procedure. First, the semiconductors were annealed in the PFD with nitrogen plasma shots after their deposition. Second, a thermal chemical vapor deposition annealed the samples for 1 h at 1050 °C by nitrogen gas at a pressure of 1 Pa. Finally, an electric furnace annealed the samples for 1 h at 1150 °C with continuous flow of nitrogen. Porous GaN structures were observed by Field emission scanning electron microscopy and atomic force microscopy. Furthermore, X-Ray diffraction analysis was carried out to determine the crystallinity of GaN after the samples were annealed. Energy-Dispersive X-Ray Spectroscopy indicated the amount of gallium, nitrogen, and oxygen due to the self-oxidation of the samples. Photoluminescence spectroscopy revealed emissions at 2.94 eV and 3.39 eV, which shows that hexagonal wurtzite crystal structures were formed.
Comparison between helium plasma induced surface structures in group 5 (Nb, Ta) and group 6 elements (Mo, W)
Authors: Omori K. , Ito A. M. , Shiga K. , Yamashita N. , Ibano K. , Lee H. T. , Ueda Y.
Published: April 2017

Group 5 elements (niobium and tantalum) and group 6 elements (molybdenum and tungsten) were exposed to helium plasma, and the resulting surface structures were observed by electron microscopy. Group 5 elements showed hole structures, where the size of the holes ranged from several tens of nm to a few hundred nm in diameter, while group 6 elements showed fiber-like structures. As a first step in understanding such differences, the difference in helium agglomeration energies and changes in the stress tensor as a function of the number of He atoms at interstitial sites were investigated for each element using density functional theory. The calculations revealed that helium atoms prefer to agglomerate in both of these groups. However, helium in group 6 elements can agglomerate more easily than group 5 elements due to higher binding energy. These results indicate a possible correlation between the shape of helium plasma induced surface nanostructures and the atomic level properties due to helium agglomeration.
Nonlocal metasolid response of homogenized phononic crystals
Authors: Konovalenko A. , Gutiérrez-Reyes E. , González A. L. , Flores-Méndez J. , Pérez-Rodríguez F.
Published: April 2017

The nonlocal effective dynamic mass-density and stiffness tensors for a solid 3D phononic crystal having Au inclusions embedded in a Si host matrix have been calculated. The applied homogenization theory is based on the Fourier formalism and the form-factor division approach. Using the effective parameters, the phononic band structure of the homogenized elastic crystal can be described even beyond the long wavelength limit. It is found out that the effective dynamic mass-density becomes anisotropic as the frequency of the phononic modes is increased because the nonlocal metasolid response depends on the phononic-mode polarization, the shape of the inclusions, and the type of the periodic array.
Anisotropic in-plane spin dynamics in (110)-oriented GaAs/AlGaAs multiple quantum well
Authors: Qian Xuan , Ma Jian , Ni HaiQiao , Niu ZhiChuan , Ji Yang
Published: April 2017

We studied spin dephasing processes in GaAs/AlGaAs multiple quantum wells (MQWs) grown on a semi-insulating (110)-oriented GaAs substrate using the time-resolved Kerr rotation (TRKR) technique. The TRKR spectra gives the electron g-factor in MQWs, as well as the spin dephasing time (SDT) for electron spins within the sample plane. The electron g-factor shows a strong two-fold anisotropy, while the in-plane SDT remains almost isotropic. The anisotropy of the electron g-factor increases monotonically with the spread of more electron wave functions into the AlGaAs barrier. The two-fold symmetry of the electron g-factor is discussed with a phenomenological model based on spin splitting of energy bands caused by spin-orbit coupling.
Wetting behaviour of Zn–Al filler metal on a stainless steel substrate
Authors: Yang Jinlong , Xue Songbai , Wu Yangyang , Yu Cheng-Nien , Sekulic Dusan P.
Published: April 2017

This work offers an analysis of the wetting behaviour of the Zn– xAl filler metal spreading on the stainless steel. Effects of Al content on wetting kinetics and microstructures of the re-solidified filler metal were studied in this important system of dissimilar substrates. Experimental results have confirmed that the wetting of Zn– xAl filler metal on stainless steel features the trend of triple-line kinetics. In the main spreading phase, the spreading radius and time can be correlated with a power law of Rn ∼  t, n = ∼0.4. The content of Al in the filler metal has a minimal effect on the value of n for the investigated range of Al concentrations. However, the spreading area of the filler metal after re-solidification decreases with an increase of the content of Al. Moreover, the thickness of the Fe–Al intermetallic layer at the cross-section increases with an increasing Al content.
Suppression of integrin α3β1 by α9β1 in the epidermis controls the paracrine resolution of wound angiogenesis
Authors: Longmate Whitney M. , Lyons Scott P. , Chittur Sridar V. , Pumiglia Kevin M. , Van De Water Livingston , DiPersio C. Michael
Published: April 2017

Development of wound therapies is hindered by poor understanding of combinatorial integrin function in the epidermis. In this study, we generated mice with epidermis-specific deletion of α3β1, α9β1, or both integrins as well as keratinocyte lines expressing these integrin combinations. Consistent with proangiogenic roles for α3β1, α3-null keratinocytes showed reduced paracrine stimulation of endothelial cell migration and survival, and wounds of epidermis-specific α3 knockout mice displayed impaired angiogenesis. Interestingly, α9β1 in keratinocytes suppressed α3β1-mediated stimulation of endothelial cells, and wounds of epidermis-specific α9 knockout mice displayed delayed vascular normalization and reduced endothelial apoptosis, indicating that α9β1 cross-suppresses α3β1 proangiogenic functions. Moreover, α9β1 inhibited α3β1 signaling downstream of focal adhesion kinase (FAK) autoactivation at the point of Src-mediated phosphorylation of FAK Y861/Y925. Finally, α9β1 cross-suppressed many α3β1-dependent genes, including the gene that encodes MMP-9, which we implicated as a regulator of integrin-dependent cross talk to endothelial cells. Our findings identify a novel physiological context for combinatorial integrin signaling, laying the foundation for therapeutic strategies that manipulate α9β1 and/or α3β1 during wound healing.
Isoflurane modulates activation and inactivation gating of the prokaryotic Na+ channel NaChBac
Authors: Sand Rheanna M. , Gingrich Kevin J. , Macharadze Tamar , Herold Karl F. , Hemmings Hugh C.
Published: April 2017

Voltage-gated Na+ channels (Nav) have emerged as important presynaptic targets for volatile anesthetic (VA) effects on synaptic transmission. However, the detailed biophysical mechanisms by which VAs modulate Nav function remain unclear. VAs alter macroscopic activation and inactivation of the prokaryotic Na+ channel, NaChBac, which provides a useful structural and functional model of mammalian Nav. Here, we study the effects of the common general anesthetic isoflurane on NaChBac function by analyzing macroscopic Na+ currents (INa) in wild-type (WT) channels and mutants with impaired (G229A) or enhanced (G219A) inactivation. We use a previously described six-state Markov model to analyze empirical WT and mutant NaChBac channel gating data. The model reproduces the mean empirical gating manifest in INa time courses and optimally estimates microscopic rate constants, valences (z), and fractional electrical distances (x) of forward and backward transitions. The model also reproduces gating observed for all three channels in the absence or presence of isoflurane, providing further validation. We show using this model that isoflurane increases forward activation and inactivation rate constants at 0 mV, which are associated with estimated chemical free energy changes of approximately −0.2 and −0.7 kcal/mol, respectively. Activation is voltage dependent (z ≈ 2e0, x ≈ 0.3), inactivation shows little voltage dependence, and isoflurane has no significant effect on either. Forward inactivation rate constants are more than 20-fold greater than backward rate constants in the absence or presence of isoflurane. These results indicate that isoflurane modulates NaChBac gating primarily by increasing forward activation and inactivation rate constants. These findings support accumulating evidence for multiple sites of anesthetic interaction with the channel.
A new method to study the change of miRNA–mRNA interactions due to environmental exposures
Authors: Petralia Francesca , Aushev Vasily N , Gopalakrishnan Kalpana , Kappil Maya , W Khin Nyan , Chen Jia , Teitelbaum Susan L , Wang Pei
Published: April 2017

Motivation

Integrative approaches characterizing the interactions among different types of biological molecules have been demonstrated to be useful for revealing informative biological mechanisms. One such example is the interaction between microRNA (miRNA) and messenger RNA (mRNA), whose deregulation may be sensitive to environmental insult leading to altered phenotypes. The goal of this work is to develop an effective data integration method to characterize deregulation between miRNA and mRNA due to environmental toxicant exposures. We will use data from an animal experiment designed to investigate the effect of low-dose environmental chemical exposure on normal mammary gland development in rats to motivate and evaluate the proposed method.

Results

We propose a new network approach—integrative Joint Random Forest (iJRF), which characterizes the regulatory system between miRNAs and mRNAs using a network model. iJRF is designed to work under the high-dimension low-sample-size regime, and can borrow information across different treatment conditions to achieve more accurate network inference. It also effectively takes into account prior information of miRNA–mRNA regulatory relationships from existing databases. When iJRF is applied to the data from the environmental chemical exposure study, we detected a few important miRNAs that regulated a large number of mRNAs in the control group but not in the exposed groups, suggesting the disruption of miRNA activity due to chemical exposure. Effects of chemical exposure on two affected miRNAs were further validated using breast cancer human cell lines.

Availability and implementation

R package iJRF is available at CRAN.

Supplementary information

Supplementary data are available at Bioinformatics online.
Exploiting sequence-based features for predicting enhancer–promoter interactions
Authors: Yang Yang , Zhang Ruochi , Singh Shashank , Ma Jian
Published: April 2017

Motivation

A large number of distal enhancers and proximal promoters form enhancer–promoter interactions to regulate target genes in the human genome. Although recent high-throughput genome-wide mapping approaches have allowed us to more comprehensively recognize potential enhancer–promoter interactions, it is still largely unknown whether sequence-based features alone are sufficient to predict such interactions.

Results

Here, we develop a new computational method (named PEP) to predict enhancer–promoter interactions based on sequence-based features only, when the locations of putative enhancers and promoters in a particular cell type are given. The two modules in PEP (PEP-Motif and PEP-Word) use different but complementary feature extraction strategies to exploit sequence-based information. The results across six different cell types demonstrate that our method is effective in predicting enhancer–promoter interactions as compared to the state-of-the-art methods that use functional genomic signals. Our work demonstrates that sequence-based features alone can reliably predict enhancer–promoter interactions genome-wide, which could potentially facilitate the discovery of important sequence determinants for long-range gene regulation.

Availability and Implementation

The source code of PEP is available at: https://github.com/ma-compbio/PEP.

Supplementary information

Supplementary data are available at Bioinformatics online.
Surgical Microanatomy of the Posterior Condylar Emissary Vein and its Anatomical Variations for the Transcondylar Fossa Approach
Authors: Ota Nakao , Tanikawa Rokuya , Yoshikane Tsutomu , Miyama Masataka , Miyazaki Takanori , Kinoshita Yu , Matsukawa Hidetoshi , Yanagisawa Takeshi , Sakakibara Fumihiro , Suzuki Go , Saito Norihiro , Miyata Shiro , Noda Kosumo , Tsuboi Toshiyuki , Takeda Rihei , Kamiyama Hiroyasu , Tokuda Sadahisa , Kamada Kyousuke
Published: April 2017

BACKGROUND: It is essential to identify and be aware of the anatomy of the posterior condylar emissary vein (PCEV) for achieving an adequate operative field for the transcondylar fossa approach (TCFA).

OBJECTIVE: To describe the variations in the drainage patterns of PCEVs and the technical issues encountered in such cases.

METHODS: This was a retrospective analysis of the anatomy of PCEVs in 104 sides in 52 cases treated by the TCFA. Preoperative findings of multidetector-row computed tomography (CT) and CT venography (CTV) were compared with the intraoperative findings. The drainage patterns were classified as 5 types: the sigmoid sinus (SS), jugular bulb (JB), occipital sinus (OS), anterior condylar emissary vein (ACEV), and marginal sinus (MS).

RESULTS: The SS, JB, ACEV, and OS types were observed in 33 (31.7%), 42 (40.3%), 8 (7.7%), and 1 (1.0%) side(s), respectively. One side (1.0%) each had combined drainage from MS and JB, and ACEV and JB, respectively. In 17 sides (16.3%), the PCEVs and posterior condylar canals could not be identified on CT and CTV.

CONCLUSIONS: Preoperative CT and CTV findings correlated well with the intraoperative findings. To make a sufficient operative field for TCFA, PCEVs should be appropriately dealt with based on the preoperative knowledge of their running course, pattern, and origin.
Functional Effects of Soybean Concentrates Obtained from Sprouted Seeds Enriched in Selenium in Wheat Breadmaking
Authors: Lazo‐Velez Marco A. , Mata‐Ramírez Daniel , Serna‐Saldivar Sergio O. , Chuck‐Hernandez Cristina
Published: April 2017

Selenium is an essential mineral in nutrition, and a proper intake of this element in its organic form has been related to body protection against cancer. The objective of this study was to evaluate the protein functionality of soybean concentrates as affected by germination and selenium addition in yeast‐leavened pan breads. Protein concentrates from germinated and selenized soybean were obtained. All protein concentrates (from germinated and selenized samples) showed similar properties, with exception of 1) water solubility index (23% for raw soybean and 43% for germinated concentrated) and 2) water absorption index (2.45 for raw soybean and 4.07 for germinated and selenized soybean concentrate). Bread made with composite flours (wheat plus 6–7% soybean concentrates) showed changes in oven spring, bread volume, and density, with selenized and germinated treatments as the most different loaves when compared with wheat‐based products. Bread crumb texture was similar among samples, except for products containing germinated material, for which a higher hardness was reached after 24 h. The use of germinated and selenized soybean concentrates in yeast‐leavened wheat bread has not been reported before, and besides the enhancement in nutritional properties, functional properties such as water absorption of final products could be improved.