During deposition, modification, and etching of thin films and nanomaterials in reactive plasmas, many active species can interact with the sample simultaneously. This includes reactive neutrals formed by fragmentation of the feed gas, positive ions, and electrons generated by electron-impact ionization of the feed gas and fragments, excited states (in particular, long-lived metastable species), and photons produced by spontaneous de-excitation of excited atoms and molecules. Notably, some of these species can be transiently present during the different phases of plasma processing, such as etching of thin layer deposition.
View Article and Find Full Text PDFThe performance of modular, networked quantum technologies will be strongly dependent upon the quality of their quantum light-matter interconnects. Solid-state colour centres, and in particular T centres in silicon, offer competitive technological and commercial advantages as the basis for quantum networking technologies and distributed quantum computing. These newly rediscovered silicon defects offer direct telecommunications-band photonic emission, long-lived electron and nuclear spin qubits, and proven native integration into industry-standard, CMOS-compatible, silicon-on-insulator (SOI) photonic chips at scale.
View Article and Find Full Text PDFNecrotizing lymphadenitis (NL) is a rare entity that can occur as a complication of bacterial cervical lymphadenitis (CL) and is characterized by unilateral or bilateral cervical lymphadenopathy. NL most commonly presents in females and most reports have been in Japan. In this case, we present a 37-year-old male with no significant past medical history who presented with an unusual presentation and clinical course of NL.
View Article and Find Full Text PDFCocaine use is rising in persons ≥50 years old and in black and socioeconomically disadvantaged communities. Cocaine-induced bowel ischemia and gastrointestinal injury are deadly findings that have been previously described in the literature. In this report, we present a case of small bowel ischemia, perforation, and upper gastrointestinal hemorrhage co-occurring in a 62-year-old incarcerated male with a 15-year history of cocaine use.
View Article and Find Full Text PDFThe global quantum internet will require long-lived, telecommunications-band photon-matter interfaces manufactured at scale. Preliminary quantum networks based on photon-matter interfaces that meet a subset of these demands are encouraging efforts to identify new high-performance alternatives. Silicon is an ideal host for commercial-scale solid-state quantum technologies.
View Article and Find Full Text PDFWe report on the cross-calibration of Thomson Parabola (TP) and Time-of-Flight (TOF) detectors as particle diagnostics, implemented on the most recent setup of the ALLS 100 TW laser-driven ion acceleration beamline. The Microchannel Plate (MCP) used for particle detection in the TP spectrometer has been calibrated in intensity on the tandem linear accelerator at the Université de Montréal. The experimental data points of the scaling factor were obtained by performing a pixel cluster analysis of single proton impacts on the MCP.
View Article and Find Full Text PDFAlthough female rats are typically described as having a promiscuous mating strategy, if sexually naïve females have their formative sexually rewarding experiences paired with the same male, they will recognize that male and display mate-guarding behavior towards him in the presence of a female competitor. Female rats that display mate guarding behavior also show enhanced activation of oxytocin and vasopressin neurons in the supraoptic and paraventricular hypothalamic nucleus. Here, we examined the potential role that histone demethylation might have in establishing this pair-bonded behavior, and whether the corresponding changes in oxytocin and vasopressin neuronal activation depended on demethylation.
View Article and Find Full Text PDFObjectives/aims: To explore students' opinion about theoretical and clinical training in tooth extraction at different European dental schools.
Materials And Methods: An online questionnaire, containing 36 dichotomous, multiple choice and Likert scale rating questions, was distributed among students of 56 different dental schools. After excluding schools where <20 students responded, 656 questionnaires from 23 dental schools remained for statistical analysis.
The nature of disorder in amorphous silicon (a-Si) is explored by investigating the spatial arrangement and energies of coordination defects in a numerical model. Spatial correlations between structural defects are examined on the basis of a parameter that quantifies the probability for two sites to share a bond. Pentacoordinated atoms are found to be the dominant coordination defects.
View Article and Find Full Text PDFJ Phys Condens Matter
July 2015
Based on a detailed study of the radial distribution function (RDF) of a model for amorphous silicon (a-Si), we address the relation between short-range rearrangements and an increase in medium-range order induced by thermal relaxation. Recent experimental measurements have shown that a small peak appears in the RDF around 4.7 Å upon annealing, along with other subtle changes, and this is attributed to ordering among the dihedral angles.
View Article and Find Full Text PDFWe have shown previously that female rats given their first copulatory experiences with the same male rat display mate guarding behavior in the presence of that male provided a female competitor is also present. Females given access to the familiar male show more Fos induction within regions of the brain that contain oxytocin (OT) and vasopressin (AVP) cell bodies, notably the supraoptic (SON) and paraventricular nuclei (PVN) relative to females given sexual experience with different males. The present experiments examined whether the Fos induction we previously observed within the SON and PVN occurred within OT and/or AVP neurons, and whether exogenous administration of OT or AVP prior to female rats first sexual experience could potentiate the acquisition of mate guarding behavior.
View Article and Find Full Text PDFWe report the results of highly sensitive transmission X-ray scattering measurements performed at the Advanced Photon Source, Argonne National Laboratory, on nearly fully dense high-purity amorphous-silicon (a-Si) samples for the purpose of determining their degree of hyperuniformity. A perfectly hyperuniform structure has complete suppression of infinite-wavelength density fluctuations, or, equivalently, the structure factor S(q→0) = 0; the smaller the value of S(0), the higher the degree of hyperuniformity. Annealing was observed to increase the degree of hyperuniformity in a-Si where we found S(0) = 0.
View Article and Find Full Text PDFTreacy and Borisenko (Reports, 24 February 2012, p. 950) argue from reverse Monte Carlo modeling of electron diffraction and fluctuation electron microscopy data that amorphous silicon is paracrystalline and not described by a continuous random network. However, their models disagree with high-resolution x-ray measurements and other evidence, whereas the agreement with fluctuation electron microscopy is at best qualitative.
View Article and Find Full Text PDFHigh energy x-ray diffraction measurements of pure amorphous Ge were made and its radial distribution function (RDF) was determined at high resolution, revealing new information on the atomic structure of amorphous semiconductors. Fine structure in the second peak in the RDF provides evidence that a fraction of third neighbors are closer than some second neighbors; taking this into account leads to a narrow distribution of tetrahedral bond angles, (8.5 ± 0.
View Article and Find Full Text PDFA recent publication in this journal (Gordon and Poulin, 2009) argues that the cost of the NSERC peer review exceeds the cost of giving every researcher a $30,000 baseline grant. However, the authors overestimated the ratio of peer review expenses to baseline grant cost by a factor of 26. The real cost of peer review is less than 5% of the baseline grant amount.
View Article and Find Full Text PDFWe report the fabrication of long-period optical fiber gratings by use of a refractive-index increase induced by ion implantation. Helium ions were implanted in an optical fiber core through a metal mask that had a 170-microm -pitch grating with spacing of 60 microm . We obtained a wavelength-dependent effective transmission loss by use of the grating.
View Article and Find Full Text PDFBackground And Purpose: Recanalization after coil embolization can be prevented by radiation emitted from 32P coils. We wanted to determine the upper limits of 32P activities that could be implanted onto coils with respect to the potential injury to nearby nerves, delay in organization of the clot, and effects on neointima formation and recanalization.
Methods: We studied the effects of various 32P activities on recanalization and organization of thrombus after coil occlusion of canine arteries and on neointima formation at the neck of canine carotid bifurcation aneurysms.
We investigate the formation of nanoparticles of Au in SiO(2) by multiple ion implantation steps and intermediate anneals to isolate nucleation and growth, thereby producing a narrow particle size distribution. We discuss the effects of varying the initial nucleation dose and the growth temperature and establish guidelines for synthesizing nanoparticles with improved size uniformity. By this method, we have obtained a standard deviation of 16% on an average diameter of 1.
View Article and Find Full Text PDFBackground And Purpose: Endovascular treatment of intracranial aneurysms is safe and effective but is associated with angiographic recurrences. Beta radiation prevents recanalization after coil embolization in experimental models. We wanted to assess the feasibility of using radioactive coil embolization to improve long-term results of endovascular treatment.
View Article and Find Full Text PDFBackground And Purpose: Beta radiation prevents recanalization after coil embolization. We sought to determine the effects of varying coil caliber, length, activity of 32P per centimeter of coil or per volume, and spatial distribution of coils on recanalization.
Methods: We studied the angiographic evolution of 81 canine maxillary, cervical, and vertebral arteries implanted with a variety of nonradioactive (n=29 arteries) or radioactive (n=52) devices.
Background And Purpose: Beta radiation can prevent recanalization after embolization. Our goal was to assess the feasibility of endovascular treatment of intracranial aneurysms using coils of a predetermined activity of 32P per centimeter.
Methods: We studied the total length of coils deployed into 357 intracranial aneurysms.
Background And Purpose: Endovascular treatment of cerebral aneurysms, a minimally invasive alternative to surgery, is too often followed by recanalization and recurrences. The purpose of this work was to assess if in situ beta radiation can inhibit recanalization after coil embolization.
Methods: Radioactive platinum coils (32P-coils) were produced by ion implantation of 32P.
Phys Rev B Condens Matter
February 1996