Introduction: Early home visit programmes have been developed to help parents build an adequate relationship with their baby and to prevent child developmental delays and affective disorders. The "Appui Parental" programme is an intervention carried out by nursery nurses to provide intensive parental support to vulnerable families. Before extending this programme, it seemed necessary to evaluate its impact objectively.
View Article and Find Full Text PDFAtomic devices such as atomic clocks and optically-pumped magnetometers rely on the interrogation of atoms contained in a cell whose inner content has to meet high standards of purity and accuracy. Glass-blowing techniques and craftsmanship have evolved over many decades to achieve such standards in macroscopic vapor cells. With the emergence of chip-scale atomic devices, the need for miniaturization and mass fabrication has led to the adoption of microfabrication techniques to make millimeter-scale vapor cells.
View Article and Find Full Text PDFTransition in mental health care is the process ensuring continuity of care of a young patient arriving at the CAMHS (Child and Adolescent Mental Health Service) age boundary within mental health services. Transition refers to a transfer to an adult mental health service (AMHS), to private care or other mental health community services. A transition plan can also lead to a managed end of specialized care with involvement of a general practitioner or social services.
View Article and Find Full Text PDFPurpose: The service configuration with distinct child and adolescent mental health services (CAMHS) and adult mental health services (AMHS) may be a barrier to continuity of care. Because of a lack of transition policy, CAMHS clinicians have to decide whether and when a young person should transition to AMHS. This study describes which characteristics are associated with the clinicians' advice to continue treatment at AMHS.
View Article and Find Full Text PDFObjectives: Several studies have shown that in young children, behavioural and/or emotional disorders are more difficult to manage than regulatory disorders. Moreover, data are lacking on outcome predictive factors. This article presents a short synthesis of previous research about outcome predictive factors in child psychiatry.
View Article and Find Full Text PDFObjectives: Stereotactic radiosurgery (SRS) is part of the multimodality treatment for patients with cancer. The objective of this study is to determine factors which influence overall survival (OS) of Filipino patients who underwent SRS for metastatic tumors of the spine.
Methods: This is a retrospective analysis of a cohort of Filipino patients treated with spine SRS for metastatic tumors in a single institution.
Purpose: The presence of distinct child and adolescent mental health services (CAMHS) and adult mental health services (AMHS) impacts continuity of mental health treatment for young people. However, we do not know the extent of discontinuity of care in Europe nor the effects of discontinuity on the mental health of young people. Current research is limited, as the majority of existing studies are retrospective, based on small samples or used non-standardised information from medical records.
View Article and Find Full Text PDFWe describe a high-performance, compact optical frequency standard based on a microfabricated Rb vapor cell and a low-noise, external cavity diode laser operating on the Rb two-photon transition at 778 nm. The optical standard achieves an instability of 1.8×10 for times less than 100 s and a flicker noise floor of 1×10 out to 6000 s.
View Article and Find Full Text PDFWe show that micro-machined non-evaporable getter pumps (NEGs) can extend the time over which laser cooled atoms can be produced in a magneto-optical trap (MOT), in the absence of other vacuum pumping mechanisms. In a first study, we incorporate a silicon-glass microfabricated ultra-high vacuum (UHV) cell with silicon etched NEG cavities and alumino-silicate glass (ASG) windows and demonstrate the observation of a repeatedly-loading MOT over a 10 min period with a single laser-activated NEG. In a second study, the capacity of passive pumping with laser activated NEG materials is further investigated in a borosilicate glass-blown cuvette cell containing five NEG tablets.
View Article and Find Full Text PDFOptical frequency standards, or lasers stabilized to atomic or molecular transitions, are widely used in length metrology and laser ranging, provide a backbone for optical communications and lie at the heart of next-generation optical atomic clocks. Here we demonstrate a compact, low-power optical frequency reference based on the Doppler-free, two-photon transition in rubidium-87 at 778 nm implemented on a micro-optics breadboard. Our optical reference achieves a fractional frequency instability of 2.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
July 2020
The adsorption of 2-mercaptobenzothiazole (2-MBT) vapor on a Cu(111) surface under ultra-low pressure was investigated. For an exposure of 45 L at 150 °C, a Moiré pattern was observed as a result of the superposition of an underlying R30° structure and an outer layer compressed by 18% and rotated by 1.2°.
View Article and Find Full Text PDFAn amendment to this paper has been published and can be accessed via a link at the top of the paper.
View Article and Find Full Text PDFIEEE Trans Ultrason Ferroelectr Freq Control
December 2019
The demonstration of miniature atomic clocks (MACs) based on coherent population trapping (CPT) with improved mid- and long-term frequency stability benefits from the implementation of additional stabilization loops to reduce temperature-induced light-shift effects. In this article, we report and highlight the individual and combined benefits of such servo loops on the frequency stability of a CPT-based MAC. The first loop stabilizes the actual temperature of the vertical-cavity surface-emitting laser (VCSEL) chip using a compensation method in which the reading of external temperature variations is derived from the atomic vapor output signal.
View Article and Find Full Text PDFThe efficient light-matter interaction and discrete level structure of atomic vapors made possible numerous seminal scientific achievements including time-keeping, extreme non-linear interactions, and strong coupling to electric and magnetic fields in quantum sensors. As such, atomic systems can be regarded as a highly resourceful quantum material platform. Recently, the field of thin optical elements with miniscule features has been extensively studied demonstrating an unprecedented ability to control photonic degrees of freedom.
View Article and Find Full Text PDFIEEE Trans Ultrason Ferroelectr Freq Control
June 2018
This paper reports a dedicated theoretical and experimental study on the properties (signal amplitude and linewidth) of coherent population trapping resonances detected in vacuum vapor cells. Results are presented for conventional single-lambda schemes of atomic energy levels but also for double-lambda schemes, now widely used in various applications including atomic clocks and magnetometers. Approximate compact analytical expressions, valid for a wide range of light-wave intensities, i.
View Article and Find Full Text PDFIn this work, we addressed the local degradation mechanisms limiting the prelaunch environmental durability of thin-layered silver stacks for demanding space mirror applications. Local initiation and propagation of tarnishing were studied by combined surface and interface analysis on model stack samples consisting of thin silver layers supported on lightweight SiC substrates and protected by thin SiO overcoats, deposited by cathodic magnetron sputtering and submitted to accelerated aging in gaseous HS. The results show that tarnishing is locally initiated by the formation of AgS columns erupting above the stack surface.
View Article and Find Full Text PDFAtomic level characterization brings fundamental insight into the mechanisms of self-protection against corrosion of metals and alloys by oxide passive films and into how localized corrosion is initiated on passivated metal surfaces. This is illustrated in this overview with selected data obtained at the subnanometre, i.e.
View Article and Find Full Text PDFWe report on the metrological characterization of novel commercially available 894.6 nm vertical-cavity surface-emitting lasers (VCSELs), dedicated to Cs D line spectroscopy experiments. The thermal behavior of the VCSELs is reported, highlighting the existence of a minimum threshold current and maximum output power in the 55°C-60°C range.
View Article and Find Full Text PDFPorous TiNx Oy -based particles were synthesized by an aerosol spray process. At first, the starting sol solution containing the metal precursor and the nitrogen source is sprayed to form an aerosol that is subsequently pyrolysed at different temperatures. The obtained dried particles are an amorphous coordination "polymer" rich in carbon and nitrogen.
View Article and Find Full Text PDFThis paper reports on an original architecture of microfabricated alkali vapor cell designed for miniature atomic clocks. The cell combines diffraction gratings with anisotropically etched single-crystalline silicon sidewalls to route a normally-incident beam in a cavity oriented along the substrate plane. Gratings have been specifically designed to diffract circularly polarized light in the first order, the latter having an angle of diffraction matching the (111) sidewalls orientation.
View Article and Find Full Text PDFWe report on the characterization of Cs vapor microfabricated cells filled with a Ne-He buffer gas mixture using coherent population trapping (CPT) spectroscopy. The temperature dependence of the Cs clock frequency is found to be canceled at the first order around a so-called inversion temperature higher than 80°C whose value depends on the buffer gas partial pressure ratio. This buffer gas mixture could be well-adapted for the development of miniature atomic clocks devoted to be used in specific applications such as defense and avionic systems with high operating temperature environment (typically higher than 85°C).
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