bluuebunny/crossref_metadata_2025 huggingface dataset:
Aldehyde dehydrogenases inhibition eradicates leukemia stem cells while sparing normal progenitors
Authors: Venton G , Pérez-Alea M , Baier C , Fournet G , Quash G , Labiad Y , Martin G , Sanderson F , Poullin P , Suchon P , Farnault L , Nguyen C , Brunet C , Ceylan I , Costello R T
Published: September 2016

The vast majority of patients with acute myeloid leukemia (AML) achieve complete remission (CR) after standard induction chemotherapy. However, the majority subsequently relapse and die of the disease. A leukemia stem cell (LSC) paradigm has been invoked to explain this failure of CR to reliably translate into cure. Indeed, LSCs are highly enriched in CD34+CD38− leukemic cells that exhibit positive aldehyde dehydrogenase activity (ALDH+) on flow cytometry, these LSCs are resistant to currently existing treatments in AML such as cytarabine and anthracycline that, at the cost of great toxicity on normal cells, are highly active against the leukemic bulk, but spare the LSCs responsible for relapse. To try to combat the LSC population selectively, a well-characterized ALDH inhibitor by the trivial name of dimethyl ampal thiolester (DIMATE) was assessed on sorted CD34+CD38− subpopulations from AML patients and healthy patients. ALDH activity and cell viability were monitored by flow cytometry. From enzyme kinetic studies DIMATE is an active enzyme-dependent, competitive, irreversible inhibitor of ALDH1. On cells in culture, DIMATE is a powerful inhibitor of ALDHs 1 and 3, has a major cytotoxic activity on human AML cell lines. Moreover, DIMATE is highly active against leukemic populations enriched in LSCs, but, unlike conventional chemotherapy, DIMATE is not toxic for healthy hematopoietic stem cells which retained, after treatment, their self-renewing and multi-lineage differentiation capacity in immunodeficient mice, xenografted with human leukemic cells. DIMATE eradicates specifically human AML cells and spares healthy mouse hematologic cells.
Efficient sensory cortical coding optimizes pursuit eye movements
Authors: Liu Bing , Macellaio Matthew V. , Osborne Leslie C.
Published: September 2016

In the natural world, the statistics of sensory stimuli fluctuate across a wide range. In theory, the brain could maximize information recovery if sensory neurons adaptively rescale their sensitivity to the current range of inputs. Such adaptive coding has been observed in a variety of systems, but the premise that adaptation optimizes behaviour has not been tested. Here we show that adaptation in cortical sensory neurons maximizes information about visual motion in pursuit eye movements guided by that cortical activity. We find that gain adaptation drives a rapid (<100 ms) recovery of information after shifts in motion variance, because the neurons and behaviour rescale their sensitivity to motion fluctuations. Both neurons and pursuit rapidly adopt a response gain that maximizes motion information and minimizes tracking errors. Thus, efficient sensory coding is not simply an ideal standard but a description of real sensory computation that manifests in improved behavioural performance.
A subset of RAB proteins modulates PP2A phosphatase activity
Authors: Sacco Francesca , Mattioni Anna , Boldt Karsten , Panni Simona , Santonico Elena , Castagnoli Luisa , Ueffing Marius , Cesareni Gianni
Published: September 2016

Protein phosphatase 2A (PP2A) is one of the most abundant serine–threonine phosphatases in mammalian cells. PP2A is a hetero-trimeric holoenzyme participating in a variety of physiological processes whose deregulation is often associated to cancer. The specificity and activity of this phosphatase is tightly modulated by a family of regulatory B subunits that dock the catalytic subunit to the substrates. Here we characterize a novel and unconventional molecular mechanism controlling the activity of the tumor suppressor PP2A. By applying a mass spectrometry-based interactomics approach, we identified novel PP2A interacting proteins. Unexpectedly we found that a significant number of RAB proteins associate with the PP2A scaffold subunit (PPP2R1A), but not with the catalytic subunit (PPP2CA). Such interactions occur in vitro and in vivo in specific subcellular compartments. Notably we demonstrated that one of these RAB proteins, RAB9, competes with the catalytic subunit PPP2CA in binding to PPP2R1A. This competitive association has an important role in controlling the PP2A catalytic activity, which is compromised in several solid tumors and leukemias.
Paradoxical cold conditions during the medieval climate anomaly in the Western Arctic
Authors: Jomelli Vincent , Lane Timothy , Favier Vincent , Masson-Delmotte Valerie , Swingedouw Didier , Rinterknecht Vincent , Schimmelpfennig Irene , Brunstein Daniel , Verfaillie Deborah , Adamson Kathryn , Leanni Laëtitia , Mokadem Fatima ,   ASTER Team, Aumaître Georges , Bourlès Didier L. , Keddadouche Karim
Published: September 2016

In the Northern Hemisphere, most mountain glaciers experienced their largest extent in the last millennium during the Little Ice Age (1450 to 1850 CE, LIA), a period marked by colder hemispheric temperatures than the Medieval Climate Anomaly (950 to 1250 CE, MCA), a period which coincided with glacier retreat. Here, we present a new moraine chronology based on 36Cl surface exposure dating from Lyngmarksbræen glacier, West Greenland. Consistent with other glaciers in the western Arctic, Lyngmarksbræen glacier experienced several advances during the last millennium, the first one at the end of the MCA, in ~1200 CE, was of similar amplitude to two other advances during the LIA. In the absence of any significant changes in accumulation records from South Greenland ice cores, we attribute this expansion to multi-decadal summer cooling likely driven by volcanic and/or solar forcing, and associated regional sea-ice feedbacks. Such regional multi-decadal cold conditions at the end of the MCA are neither resolved in temperature reconstructions from other parts of the Northern Hemisphere, nor captured in last millennium climate simulations.
Endocrine dysfunction following traumatic brain injury: a 5-year follow-up nationwide-based study
Authors: Yang Wei-Hsun , Chen Pau-Chung , Wang Ting-Chung , Kuo Ting-Yu , Cheng Chun-Yu , Yang Yao-Hsu
Published: September 2016

Post-traumatic endocrine dysfunction is a complication of traumatic brain injury (TBI). However, there is lack of long-term follow-up and large sample size studies. This study included patients suffering from TBI registered in the Health Insurance Database. Endocrine disorders were identified using the ICD codes: 244 (acquired hypothyroidism), 253 (pituitary dysfunction), 255 (disorders of the adrenal glands), 258 (polyglandular dysfunction), and 259 (other endocrine disorders) with at least three outpatient visits within 1 year or one admission diagnosis. Overall, 156,945 insured subjects were included in the final analysis. The 1- and 5-year incidence rates of post-traumatic endocrinopathies were 0.4% and 2%, respectively. The risks of developing a common endocrinopathy (p < 0.001) or pituitary dysfunction (P < 0.001) were significantly higher in patients with a TBI history. Patients with a skull bone fracture had a higher risk of developing pituitary dysfunction at the 1-year follow up (p value < 0.001). At the 5-year follow up, the association between intracranial hemorrhage and pituitary dysfunction (p value: 0.002) was significant. The risk of developing endocrine dysfunction after TBI increased during the entire 5-year follow-up period. Skull bone fracture and intracranial hemorrhage may be associated with short and long-term post-traumatic pituitary dysfunction, respectively.
Bacteriophages in clinical samples can interfere with microbiological diagnostic tools
Authors: Brown-Jaque Maryury , Muniesa Maite , Navarro Ferran
Published: September 2016

Bacteriophages are viruses that infect bacteria, and they are found everywhere their bacterial hosts are present, including the human body. To explore the presence of phages in clinical samples, we assessed 65 clinical samples (blood, ascitic fluid, urine, cerebrospinal fluid, and serum). Infectious tailed phages were detected in >45% of ascitic fluid and urine samples. Three examples of phage interference with bacterial isolation were observed. Phages prevented the confluent bacterial growth required for an antibiogram assay when the inoculum was taken from an agar plate containing lysis plaques, but not when taken from a single colony in a phage-free area. In addition, bacteria were isolated directly from ascitic fluid, but not after liquid enrichment culture of the same samples, since phage propagation lysed the bacteria. Lastly, Gram-negative bacilli observed in a urine sample did not grow on agar plates due to the high densities of infectious phages in the sample.
FtsZ does not initiate membrane constriction at the onset of division
Authors: Daley Daniel O. , Skoglund Ulf , Söderström Bill
Published: September 2016

The source of constriction required for division of a bacterial cell remains enigmatic. FtsZ is widely believed to be a key player, because in vitro experiments indicate that it can deform liposomes when membrane tethered. However in vivo evidence for such a role has remained elusive as it has been challenging to distinguish the contribution of FtsZ from that of peptidoglycan-ingrowth. To differentiate between these two possibilities we studied the early stages of division in Escherichia coli, when FtsZ is present at the division site but peptidoglycan synthesizing enzymes such as FtsI and FtsN are not. Our approach was to use correlative cryo-fluorescence and cryo-electron microscopy (cryo-CLEM) to monitor the localization of fluorescently labeled FtsZ, FtsI or FtsN correlated with the septal ultra-structural geometry in the same cell. We noted that the presence of FtsZ at the division septum is not sufficient to deform membranes. This observation suggests that, although FtsZ can provide a constrictive force, the force is not substantial at the onset of division. Conversely, the presence of FtsN always correlated with membrane invagination, indicating that allosteric activation of peptidoglycan ingrowth is the trigger for constriction of the cell envelope during cell division in E. coli.
Acoustic diagnosis of pulmonary hypertension: automated speech- recognition-inspired classification algorithm outperforms physicians
Authors: Kaddoura Tarek , Vadlamudi Karunakar , Kumar Shine , Bobhate Prashant , Guo Long , Jain Shreepal , Elgendi Mohamed , Coe James Y , Kim Daniel , Taylor Dylan , Tymchak Wayne , Schuurmans Dale , Zemp Roger J. , Adatia Ian
Published: September 2016

We hypothesized that an automated speech- recognition-inspired classification algorithm could differentiate between the heart sounds in subjects with and without pulmonary hypertension (PH) and outperform physicians. Heart sounds, electrocardiograms, and mean pulmonary artery pressures (mPAp) were recorded simultaneously. Heart sound recordings were digitized to train and test speech-recognition-inspired classification algorithms. We used mel-frequency cepstral coefficients to extract features from the heart sounds. Gaussian-mixture models classified the features as PH (mPAp ≥ 25 mmHg) or normal (mPAp < 25 mmHg). Physicians blinded to patient data listened to the same heart sound recordings and attempted a diagnosis. We studied 164 subjects: 86 with mPAp ≥ 25 mmHg (mPAp 41 ± 12 mmHg) and 78 with mPAp < 25 mmHg (mPAp 17 ± 5 mmHg) (p  < 0.005). The correct diagnostic rate of the automated speech-recognition-inspired algorithm was 74% compared to 56% by physicians (p = 0.005). The false positive rate for the algorithm was 34% versus 50% (p = 0.04) for clinicians. The false negative rate for the algorithm was 23% and 68% (p = 0.0002) for physicians. We developed an automated speech-recognition-inspired classification algorithm for the acoustic diagnosis of PH that outperforms physicians that could be used to screen for PH and encourage earlier specialist referral.
EXAFS reveals two Mo environments in the nitrogenase iron–molybdenum cofactor biosynthetic protein NifQ
Authors: George Simon J. , Hernandez Jose A. , Jimenez-Vicente Emilio , Echavarri-Erasun Carlos , Rubio Luis M.
Published: September 2016

Two molybdenum environments in the iron–molybdenum cofactor biosynthetic protein NifQ.
Dual-functional hard template directed one-step formation of a hierarchical porous carbon–carbon nanotube hybrid for lithium–sulfur batteries
Authors: Luo Chong , Niu Shuzhang , Zhou Guangmin , Lv Wei , Li Baohua , Kang Feiyu , Yang Quan-Hong
Published: September 2016

A hierarchical porous carbon–carbon nanotube hybrid, which can be used as a high performance carbon host for sulfur, is formed in one step using a dual-functional hard template.
Correction: A desferrioxamine B squaramide ester for the incorporation of zirconium-89 into antibodies
Authors: Rudd Stacey E. , Roselt Peter , Cullinane Carleen , Hicks Rodney J. , Donnelly Paul S.
Published: September 2016

Correction for ‘A desferrioxamine B squaramide ester for the incorporation of zirconium-89 into antibodies’ by Stacey E. Rudd et al., Chem. Commun., 2016, DOI: 10.1039/c6cc05961a.
A unified description of the double perovskite family Sr2MWO6 within a rigid ion model
Authors: Petralanda Urko , Etxebarria I.
Published: September 2016

The sequence of phase transitions and structural instabilities of the Sr2MWO6 double perovskites are investigated using a rigid ion model.
Stability of surface protons in pyridine-catalyzed CO2 reduction at p-GaP photoelectrodes
Authors: Lessio Martina , Riplinger Christoph , Carter Emily A.
Published: September 2016

Computed pKas suggest that adsorbed protons from water dissociation are stable and may play a role in CO2 reduction mechanism.
17O MAS NMR studies of oxo-based olefin metathesis catalysts: a critical assessment of signal enhancement methods
Authors: Grekov D. , Bouhoute Y. , Del Rosal I. , Maron L. , Taoufik M. , Gauvin R. M. , Delevoye L.
Published: September 2016

We assessed the DFS parameters for robust and optimal signal enhancement in 17O NMR studies of silica-supported catalysts.
Efficient light harvesting over a CdS/In2O3 photonic crystal photocatalyst for hydrogenation of 4-nitroaniline to p-phenylenediamine
Authors: Li Xiaofang , Wang Changqian , Li Bo , Shao Yu , Li Danzhen
Published: September 2016

Efficient light harvesting was observed over CdS photodeposited on In2O3 photonic crystals during the photocatalytic hydrogenation of 4-nitroaniline to p-phenylenediamine.
Planarity and multiple components promote organic photovoltaic efficiency by improving electronic transport
Authors: Goldey Matthew B. , Reid Daniel , de Pablo Juan , Galli Giulia
Published: September 2016

Establishing how the conformation of organic photovoltaic (OPV) polymers affects their electronic and transport properties is critical in order to determine design rules for new OPV materials and in particular to understand the performance enhancements recently reported for ternary blends.
Distinction strategies based on discriminant function analysis for particular steel grades at elevated temperature using stand-off LIBS
Authors: Delgado T. , Ruiz J. , Cabalín L. M. , Laserna J. J.
Published: September 2016

This work presents experimental discrimination strategies based on advanced chemometric tools for the differentiation of steel grades using stand-off laser-induced breakdown spectroscopy.
Synthesis of novel thiadiazole derivatives as selective COX-2 inhibitors
Authors: Ragab Fatma A. , Heiba Helmi I. , El-Gazzar Marwa G. , Abou-Seri Sahar M. , El-Sabbagh Walaa A. , El-Hazek Reham M.
Published: September 2016

A novel series of thiadiazole derivatives were designed and synthesized for evaluation as selective COX-2 inhibitorsin vitroand were investigatedin vivoas anti-inflammatory and analgesic agents against carrageenan-induced rat paw oedema model in irradiated rats.
One-step hydrothermal synthesis of Sc2Mo3O12:Ln3+ (Ln = Eu, Tb, Dy, Tb/Eu, Dy/Eu) nanosheets and their multicolor tunable luminescence
Authors: Zhao Bei , Yuan Li , Hu Shanshan , Zhang Xuemei , Zhou Xianju , Tang Jianfeng , Yang Jun
Published: September 2016

The energy transfer of MoO42− → Tb3+ (Dy3+) → Eu3+ and multicolor tunable emission occurred in Sc2Mo3O12 nanosheets prepared by one-step hydrothermal synthesis.
Enhanced long-term nitrogen removal by organotrophic anammox bacteria under different C/N ratio constraints: quantitative molecular mechanism and microbial community dynamics
Authors: Shu Duntao , He Yanling , Yue Hong , Gao Junling , Wang Qingyi , Yang Shucheng
Published: September 2016

The anaerobic ammonium oxidation (anammox) process has mainly been applied to NH4+–N-rich wastewater with very low levels of organic carbon (<0.5 g COD per g N).
Influence of biomaterial nanotopography on the adhesive and elastic properties of Staphylococcus aureus cells
Authors: Aguayo S. , Strange A. , Gadegaard N. , Dalby M. J. , Bozec L.
Published: September 2016

Despite the well-known beneficial effects of biomaterial nanopatterning on host tissue integration, the influence of controlled nanoscale topography on bacterial colonisation and infection remains unknown.
Enhancement in activity and shape selectivity of zeolite BEA by phosphate treatment for 2-methoxynaphthalene acylation
Authors: Hodala Janardhan L. , Halgeri Anand B. , Shanbhag Ganapati V.
Published: September 2016

Selective and green synthesis of 2-acetyl-6-methoxynaphthalene (2,6MNAC) is studied. Phosphate impregnation in smaller quantity regulates the pore of zeolite BEA. High selectivity to 2,6MNAC over BEA is due to the shape-selective property enhanced by P modification.
Strain-controlled giant magnetoresistance of a spin valve grown on a flexible substrate
Authors: Guo Q. , Xu X. G. , Zhang Q. Q. , Liu Q. , Wu Y. J. , Zhou Z. Q. , Zhu W. M. , Wu Y. , Miao J. , Jiang Y.
Published: September 2016

This paper studies the strain-controlled giant magnetoresistance (GMR) change of a top pinned spin valve with the stacking structure of Co90Fe10/Cu/Co90Fe10/IrMn fabricated on a flexible polyethylene terephthalate substrate.
MOF-derived Fe3O4/carbon octahedral nanostructures with enhanced performance as anode materials for lithium-ion batteries
Authors: Chen Yaqin , Zheng Li , Fu Yuanyuan , Zhou Rihui , Song Yonghai , Chen Shouhui
Published: September 2016

We have demonstrated a simple and feasible route to fabricate porous Fe3O4/C octahedral nanostructures by carbonizing hexagonal dipyramid Fe–MOF directly.
Nanosized inorganic porous materials: fabrication, modification and application
Authors: Zheng Haoquan , Gao Feifei , Valtchev Valentin
Published: September 2016

This review article gives insights into the recent developments in the synthesis, functionalization, and potential applications of nanosized inorganic porous materials.
Modulation of the band structures and optical properties of holey C2N nanosheets by alloying with group IV and V elements
Authors: Du Juan , Xia Congxin , Wang Tianxing , Xiong Wenqi , Li Jingbo
Published: September 2016

The band gap and optical absorption can be tuned effectively by the alloy concentration x in the C2N1−xPx and C2N1−xAsx alloys.
Simultaneous measurement of magnetic and density fluctuations via cross-polarization scattering and Doppler backscattering on the DIII-D tokamak
Authors: Rhodes T. L. , Barada K. , Peebles W. A. , Crocker N. A.
Published: September 2016

An upgraded cross-polarization scattering (CPS) system for the simultaneous measurement of internal magnetic fluctuations B̃ and density fluctuations ñ is presented. The system has eight radial quadrature channels acquired simultaneously with an eight-channel Doppler backscattering system (measures density fluctuations ñ and flows). 3-D ray tracing calculations based on the GENRAY ray tracing code are used to illustrate the scattering and geometric considerations involved in the CPS implementation on DIII-D. A unique quasi-optical design and IF electronics system allow direct comparison of B̃ and ñ during dynamic or transient plasma events (e.g., Edge Localized Modes or ELMs, L to H-mode transitions, etc.). The system design allows the interesting possibility of both magnetic-density (B̃–ñ) fluctuation and magnetic-temperature (B̃−T̃) fluctuation cross-phase measurements suitable for detailed tests of turbulence simulations.
A Fermi golden rule for quantum graphs
Authors: Lee Minjae , Zworski Maciej
Published: September 2016

We present a Fermi golden rule giving rates of decay of states obtained by perturbing embedded eigenvalues of a quantum graph. To illustrate the procedure in a notationally simpler setting, we first describe a Fermi golden rule for boundary value problems on surfaces with constant curvature cusps. We also provide a resonance existence result which is uniform on compact sets of energies and metric graphs. The results are illustrated by numerical experiments.
Spectral measurements of asymmetrically irradiated capsule backlighters
Authors: Keiter P. A. , Drake R. P.
Published: September 2016

Capsule backlighters provide a quasi-continuum x-ray spectrum over a wide range of photon energies [J. F. Hansen et al., Rev. Sci. Instrum. 79, 013504 (2008)]. Ideally one irradiates the capsule backlighter symmetrically, however, in complex experimental geometries, this is not always possible. In recent experiments we irradiated capsule backlighters asymmetrically and measured the x-ray spectrum from multiple directions. We will present time-integrated spectra over the photon energy range of 2-13 keV and time-resolved spectra over the photon energy range of 2-3 keV. We will compare the spectra from different lines of sight to determine if the laser asymmetry results in an angular dependence in the x-ray emission.
A compact, low cost Marx bank for generating capillary discharge plasmas
Authors: Dyson A. E. , Thornton C. , Hooker S. M.
Published: September 2016

We describe in detail a low power Compact Marx Bank (CMB) circuit that can provide 20 kV, 500 A pulses of approximately 100–200 ns duration. One application is the generation of capillary discharge plasmas of density ≈1018 cm−3 used in laser plasma accelerators. The CMB is triggered with a high speed solid state switch and gives a high voltage output pulse with a ns scale rise time into a 50 Ω load (coaxial cable) with <4 ns voltage jitter. Its small size (10 cm  ×  25 cm  ×  5 cm) means that it can be placed right next to the capillary discharge in the target chamber to avoid the need to impedance match. The electrical energy required per discharge is <1 J, and the CMB can be run at shot repetition rates of ≳1 Hz. This low power requirement means that the circuit can easily be powered by a small lead acid battery and, therefore, can be floated relative to laboratory earth. The CMB is readily scalable and pulses >45 kV are demonstrated in air discharges.
Imaging crystal spectrometer for high-resolution x-ray measurements on electron beam ion traps and tokamaks
Authors: Beiersdorfer P. , Magee E. W. , Hell N. , Brown G. V.
Published: September 2016

We describe a crystal spectrometer implemented on the Livermore electron beam ion traps that employ two spherically bent quartz crystals and a cryogenically cooled back-illuminated charge-coupled device detector to measure x rays with a nominal resolving power of λ/Δλ ≥ 10 000. Its focusing properties allow us to record x rays either with the plane of dispersion perpendicular or parallel to the electron beam and, thus, to preferentially select one of the two linear x-ray polarization components. Moreover, by choice of dispersion plane and focussing conditions, we use the instrument either to image the distribution of the ions within the 2 cm long trap region, or to concentrate x rays of a given energy to a point on the detector, which optimizes the signal-to-noise ratio. We demonstrate the operation and utility of the new instrument by presenting spectra of Mo34+, which prepares the instrument for use as a core impurity diagnostic on the NSTX-U spherical torus and other magnetic fusion devices that employ molybdenum as plasma facing components.
Studies on chemical charge doping related optical properties in monolayer WS2
Authors: Rivera Adriana M. , Gaur Anand P. S. , Sahoo Satyaprakash , Katiyar Ram S.
Published: September 2016

Thermal stability of quasi particles, i.e., exciton and trion, and a strong particle-particle interaction significantly tune the optical properties of atomically thin two dimensional (2D) metal dichalcogenides. The present work addresses the effect of inherent defects upon optical properties of chemical vapor deposition grown 1 L-WS2 and proposes the use of chemical transfer doping as a reversible and simple method for identification of the type of excess charge in the system. Photoluminescence (PL) studies in pristine 1 L-WS2 show that an additional band at ∼0.06 eV below trion (X±) PL band was evolved (at low temperature) which was associated to the bound exciton with charged/neutral defect. Using 7,7,8,8-Tetracyanoquinodimethane and 2,2-bis1,3-dithiolylidene as p and n-type dopants, respectively, we determined that the inherent defects/metal vacancies, which could be due to the presence of Tungsten metal deficiency, contributed in p-type nature of the pristine 1 L-WS2. Doping of 2D transition metal dichalcogenides materials with organic molecule via the surface charge transfer method is not only a way to provide a handy way to tailor the electronic and optical properties but also can be used as a tool to determine the nature of defects in the material.
Acoustic buffeting by infrasound in a low vibration facility
Authors: MacLeod B. P. , Hoffman J. E. , Burke S. A. , Bonn D. A.
Published: September 2016

Measurement instruments and fabrication tools with spatial resolution on the atomic scale require facilities that mitigate the impact of vibration sources in the environment. One approach to protection from vibration in a building’s foundation is to place the instrument on a massive inertia block, supported on pneumatic isolators. This opens the questions of whether or not a massive floating block is susceptible to acoustic forces, and how to mitigate the effects of any such acoustic buffeting. Here this is investigated with quantitative measurements of vibrations and sound pressure, together with finite element modeling. It is shown that a particular concern, even in a facility with multiple acoustic enclosures, is the excitation of the lowest fundamental acoustic modes of the room by infrasound in the low tens of Hz range, and the efficient coupling of the fundamental room modes to a large inertia block centered in the room.
Quantitative analysis of effective height of probes in microwave impedance microscopy
Authors: Wei Zhun , Ma Eric Yue , Cui Yong-Tao , Johnston Scott , Yang Yongliang , Agarwal Krishna , Kelly Michael A. , Shen Zhi-Xun , Chen Xudong
Published: September 2016

A quantitative approach is used to determine an effective height of probe beyond which the capacitance contribution is not significant in microwave impedance microscopy (MIM). We compare the effective height for three different modes of measurement, i.e., capacitance C(l) (l is the tip-sample distance), derivative of capacitance (C′(l)), and second derivative of capacitance (C″(l)). We discuss the effects of tip geometry and sample properties such as relative permittivity and sample height on the effective height with examples and analyze the implication on the spatial resolution of MIM. Finally, our results are verified by microwave impedance microscopy (MIM) measurement.
Using a priori knowledge for developing bolometric tomography in toroidal devices
Authors: Sano Ryuichi , Peterson Byron J. , Mukai Kiyofumi , Teranishi Masaru , Iwama Naofumi , Kobayashi Masahiro
Published: September 2016

In tomographic imaging of magnetically confined toroidal plasmas, a countermeasure against missing observation has been studied in terms of the adoption of prior information based on modelled plasma profiles. The Tikhonov regularization for image reconstruction is extended by the use of the Euclidean distance. A procedure of model fitting is designed in order to adaptively generate the reference image. The new method is tested on a typical example of ill-conditioned tomography, that is, the three-dimensional imaging-bolometer tomography in the large helical device. It has been found that the new method is useful for diminishing artifacts and thus for better recognizing the radiation structure of plasma.
Formation of silicon nanocrystals in silicon carbide using flash lamp annealing
Authors: Weiss Charlotte , Schnabel Manuel , Prucnal Slawomir , Hofmann Johannes , Reichert Andreas , Fehrenbach Tobias , Skorupa Wolfgang , Janz Stefan
Published: September 2016

During the formation of Si nanocrystals (Si NC) in SixC1−x layers via solid-phase crystallization, the unintended formation of nanocrystalline SiC reduces the minority carrier lifetime and therefore the performance of SixC1−x as an absorber layer in solar cells. A significant reduction in the annealing time may suppress the crystallization of the SiC matrix while maintaining the formation of Si NC. In this study, we investigated the crystallization of stoichiometric SiC and Si-rich SiC using conventional rapid thermal annealing (RTA) and nonequilibrium millisecond range flash lamp annealing (FLA). The investigated SixC1−x films were prepared by plasma-enhanced chemical vapor deposition and annealed at temperatures from 700 °C to 1100 °C for RTA and at flash energies between 34 J/cm2 and 62 J/cm2 for FLA. Grazing incidence X-ray diffraction and Fourier transformed infrared spectroscopy were conducted to investigate hydrogen effusion, Si and SiC NC growth, and SiC crystallinity. Both the Si content and the choice of the annealing process affect the crystallization behavior. It is shown that under certain conditions, FLA can be successfully utilized for the formation of Si NC in a SiC matrix, which closely resembles Si NC in a SiC matrix achieved by RTA. The samples must have excess Si, and the flash energy should not exceed 40 J/cm2 and 47 J/cm2 for Si0.63C0.37 and Si0.77C0.23 samples, respectively. Under these conditions, FLA succeeds in producing Si NC of a given size in less crystalline SiC than RTA does. This result is discussed in terms of nucleation and crystal growth using classical crystallization theory. For FLA and RTA samples, an opposite relationship between NC size and Si content was observed and attributed either to the dependence of H effusion on Si content or to the optical absorption properties of the materials, which also depend on the Si content.
Magnetic and structural properties of Fe-implanted cubic GaN
Authors: Righetti V. A. N. , Gratens X. , Chitta V. A. , de Godoy M. P. F. , Rodrigues A. D. , Abramof E. , Dias J. F. , Schikora D. , As D. J. , Lischka K.
Published: September 2016

In this article, we report on structural and magnetic properties of cubic GaN epitaxial layers implanted with Fe ions and subsequently subjected to thermal annealing. The epitaxial quality of the layers was studied by X-ray diffraction rocking curves (ω-scans) and Raman spectroscopy. The results show that the implantation damages the crystal structure producing an expansion of the lattice parameter in the implanted region. These damages are partially removed by the thermal treatment. Room temperature ferromagnetism is observed for the sample implanted with a dose of 1.2 × 1016 cm−2, while samples implanted with 2.4 × 1016 cm−2 show a coexistence of ferromagnetism and paramagnetism due to disperse Fe3+. Thermal annealing changes these magnetic properties. For the low dose sample, the ferromagnetism is converted into paramagnetism while for the high dose we observed an enhancement of the ferromagnetic contribution characterized by a superparamagnetism behavior attributed to Fe-based particles.
Gap states in the electronic structure of SnO2 single crystals and amorphous SnOx thin films
Authors: Haeberle J. , Machulik S. , Janowitz C. , Manzke R. , Gaspar D. , Barquinha P. , Schmeißer D.
Published: September 2016

The electronic structure of a SnO2 single crystal is determined by employing resonant photoelectron spectroscopy. We determine the core level, valence band, and X-ray absorption (XAS) data and compare these with those of amorphous SnOx thin films. We find similar properties concerning the data of the core levels, the valence band features, and the absorption data at the O1s edge. We find strong signals arising from intrinsic in-gap states and discuss their origin in terms of polaronic and charge-transfer defects. We deduce from the XAS data recorded at the Sn3d edge that the Sn4d10 ground state has contributions of 4d9 and 4d8 states due to configuration interaction. We identify localized electronic states depending on the strength of the 4d-5s5p interaction and of the O2p-to-Sn4d charge-transfer processes, both appear separated from the extended band-like states of the conduction band. For the amorphous SnOx thin films, significant differences are found only in the absorption data at the Sn3d-edge due to a stronger localization of the in-gap states.
Assessment of the measurement performance of the in-vessel system of gap 6 of the ITER plasma position reflectometer using a finite-difference time-domain Maxwell full-wave code
Authors: da Silva F. , Heuraux S. , Ricardo E. , Quental P. , Ferreira J.
Published: September 2016

We conducted a first assessment of the measurement performance of the in-vessel components at gap 6 of the ITER plasma position reflectometry with the aid of a synthetic Ordinary Mode (O-mode) broadband frequency-modulated continuous-wave reflectometer implemented with REFMUL, a 2D finite-difference time-domain full-wave Maxwell code. These simulations take into account the system location within the vacuum vessel as well as its access to the plasma. The plasma case considered is a baseline scenario from Fusion for Energy. We concluded that for the analyzed scenario, (i) the plasma curvature and non-equatorial position of the antenna have neglectable impact on the measurements; (ii) the cavity-like space surrounding the antenna can cause deflection and splitting of the probing beam; and (iii) multi-reflections on the blanket wall cause a substantial error preventing the system from operating within the required error margin.
Experimental observation of structures with subtle balance between strong hydrogen bond and weak n → π* interaction: Gas phase laser spectroscopy of 7-azaindole⋯fluorosubstituted pyridines
Authors: Singh Santosh K. , Vaishnav Jamuna K. , Das Aloke
Published: September 2016

In this study, interplay between a strong hydrogen bond and a very weak n → π* interaction has been probed through experiment for the first time. We have used resonant 2-photon ionization, Infrared-ultraviolet double resonance spectroscopy, and quantum chemistry calculation to determine the structures of 7-azaindole⋯2,6-difluoropyridine and 7-azaindole⋯2,3,5,6-tetrafluororpyridine complexes, which are stabilized by both hydrogen bonding and n → π* interaction. The structures of the complexes studied in the present work have been compared with the double hydrogen bonded (N–H⋯N and C–H⋯N) planar structure of 7-azaindole⋯2-fluoropyridine. It has been found that the strength of the N–H⋯N hydrogen bond in the 7-azaindole⋯2,6-substituted fluoropyridines is affected due to several factors. The main reason for huge reduction in the strength of this N–H⋯N hydrogen bond in these complexes is due to loss of the C–H⋯N hydrogen bond, through substitution of fluorine atoms in 2 and 6 positions, which induces major structural changes by bending the hydrogen bond and introducing the n → π* interaction. Effect of fluorination as well as presence of the n → π* interaction in these complexes also contributes to the reduction of the strength of the N–H⋯N interaction. Although it is difficult to quantify the role of the n → π* interaction to affect the strength of the hydrogen bond, observation of the structures, where a strong hydrogen bond and a weak n → π* interaction co-exist, is confirmed.
Resonant and nonresonant vibrational excitation of ammonia molecules in the growth of gallium nitride using laser-assisted metal organic chemical vapour deposition
Authors: Golgir Hossein Rabiee , Zhou Yun Shen , Li Dawei , Keramatnejad Kamran , Xiong Wei , Wang Mengmeng , Jiang Li Jia , Huang Xi , Jiang Lan , Silvain Jean Francois , Lu Yong Feng
Published: September 2016

The influence of exciting ammonia (NH3) molecular vibration in the growth of gallium nitride (GaN) was investigated by using an infrared laser-assisted metal organic chemical vapor deposition method. A wavelength tunable CO2 laser was used to selectively excite the individual vibrational modes. Resonantly exciting the NH-wagging mode (v2) of NH3 molecules at 9.219 μm led to a GaN growth rate of 84 μm/h, which is much higher than the reported results. The difference between the resonantly excited and conventional thermally populated vibrational states was studied via resonant and nonresonant vibrational excitations of NH3 molecules. Resonant excitation of various vibrational modes was achieved at 9.219, 10.35, and 10.719 μm, respectively. Nonresonant excitation was conducted at 9.201 and 10.591 μm, similar to conventional thermal heating. Compared to nonresonant excitation, resonant excitation noticeably promotes the GaN growth rate and crystalline quality. The full width at half maximum value of the XRD rocking curves of the GaN (0002) and GaN (10–12) diffraction peaks decreased at resonant depositions and reached its minimum value of 45 and 53 arcmin, respectively, at the laser wavelength of 9.219 μm. According to the optical emission spectroscopic studies, resonantly exciting the NH3 v2 mode leads to NH3 decomposition at room temperature, reduces the formation of the TMGa:NH3 adduct, promotes the supply of active species in GaN formation, and, therefore, results in the increased GaN growth rate.
Td-MoTe2: A possible topological superconductor
Authors: Luo X. , Chen F. C. , Zhang J. L. , Pei Q. L. , Lin G. T. , Lu W. J. , Han Y. Y. , Xi C. Y. , Song W. H. , Sun Y. P.
Published: September 2016

We measured the magnetoresistivity properties of Td-MoTe2 single crystal under the magnetic field up to 33 T. By analyzing the Shubnikov–de Haas oscillations of the longitudinal resistance Δρxx, a linear dependence of the Landau index n on 1/B is obtained. The intercept of the Landau index plot is 0.47, which is between 3/8 and 1/2. This clearly reveals a nontrivial π Berry's phase, which is a distinguished feature of the surface state in Td-MoTe2 single crystal. Accompanied by the superconductivity observed at TC = 0.1 K, Td-MoTe2 may be a promising candidate of the topological superconductor and opens a door to study the relationship between the superconductivity and topological physics.
Band alignment of Ga2O3/Si heterojunction interface measured by X-ray photoelectron spectroscopy
Authors: Chen Zhengwei , Nishihagi Kazuo , Wang Xu , Saito Katsuhiko , Tanaka Tooru , Nishio Mitsuhiro , Arita Makoto , Guo Qixin
Published: September 2016

Ga2O3 thin films were deposited on (111) Si substrate by pulsed laser deposition method. X-ray photoelectron spectroscopy has been used to determine the valence band offset at Ga2O3/Si heterojunction interface. We measured the binding energies of Si 2p and Ga 2p3/2 core levels and the valence band maxima energies. The valence band offset is determined to be 3.5 ± 0.1 eV. As a consequence a type Ι heterojunction with a conduction band offset of 0.2 ± 0.1 eV is found. The determination of the band alignment of Ga2O3/Si heterojunction facilitates the design of optical and electronic devices based on the Ga2O3/Si structure.
Diamagnetic particle separation by shape in ferrofluids
Authors: Zhou Yilong , Xuan Xiangchun
Published: September 2016

Separating particles, which can be either biological or synthetic, in a continuous label-free manner is essential to many applications. Magnetic separation has several advantages over other field-driven particle separation techniques. It, however, has been limited primarily to situations where particles differ in size or magnetization. We demonstrate in this paper a continuous-flow separation of equal-volumed spherical and peanut-shaped diamagnetic particles in a dilute ferrofluid. This separation is attributed to the shape-dependent magnetophoretic motion, which is the combined result of the shape dependences of the magnetic force and viscous drag. We also develop a three-dimensional numerical model to understand this shape-based diamagnetic particle separation and predict the effects of the determining factors.
Impact of interfacial misfit dislocation growth mode on highly lattice-mismatched InxGa1-xSb epilayer grown on GaAs substrate by metalorganic chemical vapor deposition
Authors: Huynh Sa Hoang , Ha Minh Thien Huu , Do Huy Binh , Luc Quang Ho , Yu Hung Wei , Chang Edward Yi
Published: September 2016

Highly lattice-mismatch (over 8%) ternary InxGa1-xSb alloy directly grown on GaAs substrates was demonstrated by metalorganic chemical vapor deposition (MOCVD). The influence of growth parameters, such as growth temperature, indium vapor composition, and V/III ratio, on the film properties was investigated, and it was found that the growth temperature has the strongest effect on the surface morphology and the crystal quality of the InxGa1-xSb epilayer. An optimized growth temperature of ∼590 °C and a V/III ratio of 2.5 were used for the growth of the InxGa1-xSb epilayer on GaAs that displays a lower surface roughness. High-resolution transmission electron microscopy micrographs exhibit that InxGa1-xSb epilayer growth on GaAs was governed by the interfacial misfit dislocation growth mode. Furthermore, the variation of the intermixing layer thickness at the InxGa1-xSb/GaAs heterointerface was observed. These results provide an information of growing highly lattice-mismatched epitaxial material systems by MOCVD growth process.
Staphylococcus aureus Endocarditis as a Complication of Toxocariasis-Associated Endomyocarditis With Fibrosis: A Case Report
Authors: Kuenzli Esther , Labhardt Niklaus , Balestra Gianmarco , Weisser Maja , Zellweger Michael J. , Blum Johannes
Published: September 2016

Complications associated with Toxocara canis infection are rare. We present a case of a patient with Staphylococcus aureus endocarditis as a complication of an endomyocardial fibrosis caused by T canis. The epidemiological, pathological, and clinical features of this rare complication are described here.
USE OF AFLIBERCEPT FOR THE MANAGEMENT OF REFRACTORY PSEUDOPHAKIC MACULAR EDEMA IN IRVINE-GASS SYNDROME AND LITERATURE REVIEW
Authors: Lin Chun-Ju , Tsai Yi-Yu
Published: September 2016

Background/Purpose:

To present the patient treated for pseudophakic cystoid macular edema with intravitreal aflibercept.

Methods:

Interventional case report.

Case:

An 83-year-old woman presented with decreased vision 1 month after uneventful cataract surgery. After failure to respond to posterior subtenons triamcinolone and three Ranibizumab injections, the patient responded to one intravitreal aflibercept injection. Recurrence occurred two months later, and therefore three monthly injections were then given. Again the patient responded although recurrence occurred two months after treatment. The patient refused further treatment.

Conclusion:

Intravitreal aflibercept may be effective for the treatment of pseudophakic cystoid macular edema.
Corneal Elevation Topography in Primary Open Angle Glaucoma
Authors: Gil Pedro , Pires Joana , Matos Rita , Cardoso Mariana S. , Lopes Nádia , Matias João , Mariano Manuel
Published: September 2016

Purpose of the Study:

The purpose of the study was to describe and compare anterior and posterior topographic elevation maps in primary open angle glaucoma patients with functional damage staging and in healthy controls.

Methods:

A total of 217 subjects were consecutively recruited, including 111 primary open angle glaucoma patients (patients), and 106 healthy individuals (controls). All patients performed Pentacam HR corneal topography. Mean anterior keratometry and anterior and posterior topographic elevation maps were compared in the central 3, 5, and 7 mm. Humphrey automated perimetry results from the patient group were classified according to the Glaucoma Staging System.

Results:

Age (patients: 72.32±8.09; controls: 70.82±8.36; P=0.18) and central corneal pachymetry (patients: 541.13±36.98; controls: 548.67±34.56; P=0.12) were similar in both groups. Maximum elevation readings in the central 5 mm were significantly (P<0.05) higher in the anterior (patients: 8.21±8.63; controls: 5.79±3.62) and posterior (patients: 16.17±8.72; controls: 13.92±6.03) corneal topography of the glaucomatous patients, as well as in the anterior (patients: 17.32±20.78; controls: 9.61±5.64) and posterior (patients: 38.81±19.78; controls: 26.38±12.73) central 7 mm. There was a weak but significant correlation between the Glaucoma Staging System stage and both the anterior 5 mm (r=0.397) and 7 mm (r=0.304) maximum, as well as the posterior 5 mm (r=0.233) and 7 mm (r=0.241) maximum.

Conclusions:

In patients with primary open angle glaucoma, there is a forward shifting of the posterior and anterior corneal surfaces. This appears to be correlated with more advanced stages of functional damage, pointing to a possible link between corneal structural changes and duration and intensity of elevated intraocular pressure. Further studies may ascertain the potential for this biological marker to be used in monitoring primary open angle glaucoma patients.
Cardiac Tumors
Authors: Capotosto Lidia , Elena Giulia , Massoni Francesco , De Sio Simone , Carnevale Aldo , Ricci Serafino , Vitarelli Antonio
Published: September 2016

In the past, cardiac tumors were a just clinical curiosity and the prognosis was poor. Surgical management became possible after the advent of cardiopulmonary bypass, and more recently, preoperative diagnosis was greatly improved by the development of echocardiography, computed tomography, and magnetic resonance imaging. The value of echocardiography for diagnosing cardiac mass lesions has become well established. Numerous advances have occurred in the last 5 decades, and the evolution of echocardiography involves the development of its many modalities. This review is intended to help echocardiologists and forensic pathologists in providing good medical practice when faced with the challenge of investigating unexpected clinical signs, particularly in young people, or unexpected postmortem findings.