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1.
Surgeon ; 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38693029

RESUMEN

INTRODUCTION: Surgeons are at high risk of developing musculoskeletal symptoms due to a range of factors including, maladaptive positioning and surgical ergonomics. Cervical muscle strain and biomechanical load is most prevalent due to repetitive motions and prolonged static neck positioning. This issue is apparent through reports of prevalence between 10 and 74.4% among surgeons. The aim of this systematic review is to provide an objective assessment of the clinical evidence available and a descriptive analysis of the effects of kinematics and surgical ergonomics on the prevalence of surgeons' cervical musculoskeletal pain. METHODS: This is PRISMA-compliant systematic review of clinical studies assessing the prevalence of cervical musculoskeletal dysfunction in surgeons by searching PUBMED and Ovid EMBASE databases from inception to 19th October 2023. Study quality was graded according to the National Institutes of Health study quality assessment tools. RESULTS: A total of 9 studies were included in the final qualitative analysis. The use of loupes, open surgery and excessive neck flexion (>30°) were associated with cervical dysfunction. Comparison of study outcomes was challenging due to heterogeneity within study methods and the paucity of methodological quality. CONCLUSION: The current literature assessing ergonomic and biomechanical factors predisposing surgeons to cervical musculoskeletal dysfunction is insufficient to provide reliable guidance for clinicians. Although the literature identifies factors contributing to work-related cervical dysfunction, few attempt to evaluate interventions for improved surgical ergonomics. An objective assessment of interventions that prompt postural correction with the aim to improve neck pain in surgeon cohorts is warranted.

2.
Nature ; 618(7966): 708-711, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37277615

RESUMEN

Dust grains absorb half of the radiation emitted by stars throughout the history of the universe, re-emitting this energy at infrared wavelengths1-3. Polycyclic aromatic hydrocarbons (PAHs) are large organic molecules that trace millimetre-size dust grains and regulate the cooling of interstellar gas within galaxies4,5. Observations of PAH features in very distant galaxies have been difficult owing to the limited sensitivity and wavelength coverage of previous infrared telescopes6,7. Here we present James Webb Space Telescope observations that detect the 3.3 µm PAH feature in a galaxy observed less than 1.5 billion years after the Big Bang. The high equivalent width of the PAH feature indicates that star formation, rather than black hole accretion, dominates infrared emission throughout the galaxy. The light from PAH molecules, hot dust and large dust grains and stars are spatially distinct from one another, leading to order-of-magnitude variations in PAH equivalent width and ratio of PAH to total infrared luminosity across the galaxy. The spatial variations we observe suggest either a physical offset between PAHs and large dust grains or wide variations in the local ultraviolet radiation field. Our observations demonstrate that differences in emission from PAH molecules and large dust grains are a complex result of localized processes within early galaxies.

3.
J Plast Reconstr Aesthet Surg ; 81: 88-90, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37121048

RESUMEN

Increasing numbers of patients are travelling abroad to undergo cosmetic surgery. This is associated with complications that often become the responsibility of clinicians in the patients' home countries. While seemingly lower cost treatments abroad may seem attractive, prospective patients should be made aware of the hidden costs of postoperative complications and their associated morbidity. Many internet sources of information regarding these procedures originate from commercial providers in the form of advertisements, which may not highlight the potential complications to prospective patients. Our study aims to perform an objective analysis of the quality and readability of online information for patients seeking cosmetic surgery abroad using tools such as JAMA and DISCERN scores. We found that the majority of online information available to prospective and current patients regarding travelling abroad for cosmetic surgery is unregulated, distributed by commercial providers and often lacking relevant and reliable information. Due to the strong influence that the internet can have on patients' decision making, it is important that reputable, informative online material is circulated regarding these procedures. Further work needs to be done by professional bodies and medical professionals in the plastic surgery community to improve patient education in this area.


Asunto(s)
Turismo Médico , Procedimientos de Cirugía Plástica , Cirugía Plástica , Humanos , Comprensión , Estudios Prospectivos , Internet
4.
Sci Rep ; 13(1): 127, 2023 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-36599870

RESUMEN

X-ray Microtomography is a proven tool for phase fraction analysis of multi-phase systems, provided that each phase is adequately partitioned by some means of data processing. For porosity in materials containing low-density ceramic phases, differentiation between pores and the low-density phase(s) can be intractable due to low scattering in the low-density phase, particularly if small pores necessitate low binning. We present a novel, combined methodology for accurate porosity analysis-despite these shortcomings. A 3-stage process is proposed, consisting of (1) Signal/noise enhancement using non-local means denoising, (2) Phase segmentation using a convolutional neural network, and (3) Quantitative analysis of the resulting 3D pore metrics. This particular combination of denoising and segmentation is robust against the fragmentation of common segmentation algorithms, while avoiding the volitional aspects of model selection associated with histogram fitting. We discuss the procedure applied to ternary phase SiC-TiC-diamond composites produced by reactive spark plasma sintering with porosity spanning 2-9 vol%.

5.
Skeletal Radiol ; 52(3): 517-540, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36542130

RESUMEN

BACKGROUND: New entities in the classification of bone and soft tissue tumors have been identified by use of advanced molecular-genetic techniques, including next-generation sequencing. Clinicoradiologic and pathologic correlation supports diagnostic classification. METHODS: Tumors from four morphologically grouped areas are selected to enhance diagnosis and awareness among the multidisciplinary team. These include select round cell tumors, spindle cell tumors, targetable tyrosine kinase/RAS::MAPK pathway-ovoid (epithelioid to spindled) tumors, and giant-cell-rich tumors of bone and soft tissue. RESULTS: Round cell tumors of bone and soft tissue include prototypical Ewing sarcoma, newer sarcomas with BCOR genetic alteration and CIC-rearranged, as well as updates on FUS/EWSR1::NFATc2, an EWSR1 non-ETS tumor that is solid with additional amplified hybridization signal pattern of EWSR1. This FUS/EWSR1::NFATc2 fusion has now been observed in seemingly benign to low-grade intraosseous vascular-rich and simple (unicameral) bone cyst tumors. Select spindle cell tumors of bone and soft tissue include rhabdomyosarcoma with FUS/EWSR1::TFCP2, an intraosseous high-grade spindle cell tumor without matrix. Targetable tyrosine-kinase or RAS::MAPK pathway-tumors of bone and soft tissue include NTRK, ALK, BRAF, RAF1, RET, FGFR1, ABL1, EGFR, PDGFB, and MET with variable ovoid myopericytic to spindled pleomorphic features and reproducible clinicopathologic and radiologic clues to their diagnosis. Giant-cell-rich tumors of bone, joint, and soft tissue are now respectively characterized by H3F3A mutation, CSF1 rearrangement (targetable), and HMGA2::NCOR2 fusion. CONCLUSION: This article is an update for radiologists, oncologists, surgeons, and pathologists to recognize these novel ovoid, spindled, giant-cell-rich, and round cell tumors, for optimal diagnostic classification and multidisciplinary team patient care.


Asunto(s)
Rabdomiosarcoma , Sarcoma de Ewing , Sarcoma , Neoplasias de los Tejidos Blandos , Humanos , Sarcoma/patología , Sarcoma de Ewing/patología , Factores de Transcripción/genética , Neoplasias de los Tejidos Blandos/diagnóstico por imagen , Neoplasias de los Tejidos Blandos/genética , Biomarcadores de Tumor/genética , Proteínas de Unión al ADN/genética
6.
Eat Behav ; 44: 101591, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34920208

RESUMEN

User-centered design methods aim to increase intervention engagement by focusing on consumers' needs and preferences. We conducted a needs assessment (the first step in user-centered design) via a digital diary study to understand how individuals with recurrent binge eating (≥12 episodes in 3 months) and obesity (BMI ≥30 kg/m2) manage these problems in their day-to-day lives and the approaches they use to change their behavior. Specifically, we applied the Behavior Change Technique (BCT)-Taxonomy to characterize which standardized BCTs individuals use to change binge eating and health-related behaviors and their motivations to use them, to inform the design of a mobile intervention. We analyzed qualitative data from 22 adults (64% female, 32% White) who submitted 176 diary entries. For each entry, we coded the BCTs used, motivation for use, and whether the BCT(s) were perceived as beneficial for behavior change. Across participants, investigators identified 50 of the 93 standardized BCTs (54%). Each participant used an average of 12 (SD = 4) BCTs, most commonly Behavior Substitution (72.3%), Distraction (68.2%), Goal Setting (Behavior) (63.6%), Action Planning (59.1%) and Adding Objects to the Environment (59.1%). More BCTs were coded as beneficial (49%) versus detrimental (24%) or neutral (27%). Techniques were most commonly motivated by preventing binge eating (95.5%), losing weight (95.5%), reducing unhealthy food choices (90.9%), or managing stress (59.1%). Results help inform how interventions could be designed to support consumers in changing binge eating and weight-related behaviors, although such designs would need to be tested for their impact on engagement and outcomes.


Asunto(s)
Trastorno por Atracón , Bulimia , Automanejo , Adulto , Terapia Conductista/métodos , Trastorno por Atracón/terapia , Bulimia/terapia , Femenino , Humanos , Masculino , Diseño Centrado en el Usuario
7.
Fam Syst Health ; 39(1): 19-28, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-34014727

RESUMEN

INTRODUCTION: Short message service (SMS) is a widely accepted telecommunications approach used to support health informatics, including behavioral interventions, data collection, and patient-provider communication. However, SMS delivery platforms are not standardized and platforms are typically commercial "off-the-shelf" or developed "in-house." As a consequence of platform variability, implementing SMS-based interventions may be challenging for both providers and patients. Off-the-shelf SMS delivery platforms may require minimal development or technical resources from providers, but users are often limited in their functionality. Conversely, platforms that are developed in-house are often specified for individual projects, requiring specialized development and technical expertise. Patients are on the receiving end of programming and technical specification challenges; message delays or lagged data affect quality of SMS communications. To date, little work has been done to develop a generalizable SMS platform that can be scaled across health initiatives. OBJECTIVE: We propose the Configurable Assessment Messaging Platform for Interventions (CAMPI) to mitigate challenges associated with SMS intervention implementation (e.g., programming, data collection, message delivery). METHOD: CAMPI aims to optimize health data captured from a multitude of sources and enhance patient-provider communication through a technology that is simple and familiar to patients. Using representative examples from three behavioral intervention case studies implemented among diverse populations (pregnant women, young sexual minority men, and parents with young children), we describe CAMPI capabilities and feasibility. CONCLUSION: As a generalizable SMS platform, CAMPI can be scaled to meet the priorities of various health initiatives, while reducing unnecessary resource utilization and burden on providers and patients. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Asunto(s)
Informática Médica/tendencias , Envío de Mensajes de Texto/normas , Salud de la Familia/tendencias , Estudios de Factibilidad , Humanos , Envío de Mensajes de Texto/instrumentación
8.
Curr HIV/AIDS Rep ; 18(3): 186-197, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33709323

RESUMEN

PURPOSE OF REVIEW: Given the growth in HIV-related implementation research, there is a need to expand the workforce and rigor through implementation science (IS) training and mentorship. Our objective is to review IS training opportunities for HIV-focused researchers and describe the approach and lessons learned from a recent HIV-related implementation research training initiative. RECENT FINDINGS: IS training opportunities range from degree programs to short- and longer-term professional development institutes and community-focused institutional trainings. Until recently, there have not been extensive dedicated opportunities for implementation research training for HIV-focused investigators. To meet this gap, an inter-Center for AIDS Research IS Fellowship for early-stage investigators was launched in 2019, building on lessons learned from dissemination and implementation training programs. Key components of the HIV-focused IS fellowship include didactic training, mentorship, grant-writing, and development of HIV-IS collaborative networks. Fellows to-date were two-thirds junior faculty and one-third post-doctoral fellows, the majority (69%) with prior public health training. Perceived value of the program was high, with a median rating of 9 [IQR 8-9] on a 10-point scale. Overall, 22/27 (81%) Fellows from the first cohort submitted IS-related grants within 12 months of Fellowship completion, and by 1 year 13 grants had been funded among 10 investigators, 37% overall among Fellows. Mentors identified framing of IS questions as the top-ranked training priority for HIV-investigators. Increasing knowledge of the utility of IS may support more grants focused on optimal implementation of HIV treatment and prevention strategies. Experiences from mentors and trainees engaged in an IS-focused fellowship for HIV investigators demonstrate the demand and value of a dedicated training program and reinforce the importance of mentorship.


Asunto(s)
Infecciones por VIH , Becas , Infecciones por VIH/prevención & control , Humanos , Ciencia de la Implementación , Mentores
9.
JMIR Form Res ; 4(9): e18412, 2020 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-32955450

RESUMEN

BACKGROUND: Unmanaged cancer symptoms and treatment-related side effects can compromise long-term clinical outcomes and health-related quality of life. Health information technologies such as web-based platforms offer the possibility to supplement existing care and optimize symptom management. OBJECTIVE: This paper describes the development and usability of a web-based symptom management platform for cancer patients and survivors that will be implemented within a large health system. METHODS: A web-based symptom management platform was designed and evaluated via one-on-one usability testing sessions. The System Usability Scale (SUS), After Scenario Questionnaire (ASQ), and qualitative analysis of semistructured interviews were used to assess program usability. RESULTS: Ten cancer survivors and five cancer center staff members participated in usability testing sessions. The mean score on the SUS was 86.6 (SD 14.0), indicating above average usability. The mean score on the ASQ was 2.5 (SD 2.1), indicating relatively high satisfaction with the usability of the program. Qualitative analyses identified valued features of the program and recommendations for further improvements. CONCLUSIONS: Cancer survivors and oncology care providers reported high levels of acceptability and usability in the initial development of a web-based symptom management platform for cancer survivors. Future work will test the effectiveness of this web-based platform.

10.
J Community Psychol ; 48(4): 1178-1193, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31951291

RESUMEN

AIMS: To translate evidence-based programs (EBP) for a new setting, attention must be given to the characteristics of the intervention and the local setting, as well as evidence that is compelling to decision-makers. This paper describes the history of a partnership and stakeholder recommendations to inform the adaptation of an EBP for primary care. METHODS: We established a community advisory board (CAB) consisting of stakeholders with expertize in primary care delivery. A thematic analysis was conducted with fieldnotes and transcriptions from CAB meetings and regular meetings with participating clinics. RESULTS: We found that (a) parenting programs with a focus on behavioral and physical health are appropriate for this setting, (b) variability in the structure of primary care means implementation must be tailorable, and (c) financial and organizational outcomes are compelling for decision-makers. CONCLUSION: Factors related to the content and structure of evidence-based programs are uniquely related to distinct implementation outcomes of interest to key stakeholders.


Asunto(s)
Práctica Clínica Basada en la Evidencia/organización & administración , Responsabilidad Parental , Atención Primaria de Salud/métodos , Participación de los Interesados , Niño , Toma de Decisiones , Femenino , Humanos , Ciencia de la Implementación , Masculino , Evaluación de Necesidades/organización & administración , Obesidad Infantil/terapia , Relaciones Médico-Paciente
11.
Artículo en Inglés | MEDLINE | ID: mdl-34667480

RESUMEN

BACKGROUND: Virtual Reality Job-Interview Training (VR-JIT) is an efficacious Internet-based intervention for adults with severe mental illness (SMI). Evaluations of VR-JIT have shown improved interview skill and access to employment in several cohorts of adults with SMI and with autism spectrum disorders (ASD). VR-JIT trains participants how to fill out job applications and handle job interviews through e-learning content and applied practice. Trainees receive feedback through in-the-moment nonverbal cues, critiques, and recommendations for improving performance. Our study sought to adapt VR-JIT for transition-age youth with ASD (TAY-ASD). METHODS: We recruited TAY-ASD and adult stakeholders from public and charter schools, transition programs, and community service providers. Participants provided feedback on VR-JIT to enhance its applicability to TAY-ASD. We used community-engaged methods to process and analyze data from TAY-ASD and stakeholders, presented their quantitative and qualitative responses to community and scientific advisory boards for review and recommendations, and adapted the intervention design and content. RESULTS: Our adaptations included adding diversity (gender; race/ethnicity) to the virtual hiring manager; shortening the interview by reducing response options; increasing social storytelling to enhance engagement with VR-JIT core components; adding employment opportunities more relevant to younger workers; reducing the reading level; and making the e-learning content more accessible by adding bullet points, voiceover, and imagery/video; and adding new learning goals. CONCLUSIONS: This study presents a rigorous and innovative community-engaged methodology for adapting VR-JIT to meet the needs of TAY-ASD. We review our engagement with TAY-ASD and stakeholders, and discuss the standardized coding scheme we used to adapt VR-JIT and the usefulness and limitations of employing this methodology in adapting other behavioral interventions.

12.
Environ Int ; 134: 105188, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31787325

RESUMEN

INTRODUCTION: Despite the London Underground (LU) handling on average 2.8 million passenger journeys per day, the characteristics and potential health effects of the elevated concentrations of metal-rich PM2.5 found in this subway system are not well understood. METHODS: Spatial monitoring campaigns were carried out to characterise the health-relevant chemical and physical properties of PM2.5 across the LU network, including diurnal and day-to-day variability and spatial distribution (above ground, depth below ground and subway line). Population-weighted station PM2.5 rankings were produced to understand the relative importance of concentrations at different stations and on different lines. RESULTS: The PM2.5 mass in the LU (mean 88 µg m-3, median 28 µg m-3) was greater than at ambient background locations (mean 19 µg m-3, median 14 µg m-3) and roadside environments in central London (mean 22 µg m-3, median 14 µg m-3). Concentrations varied between lines and locations, with the deepest and shallowest submerged lines being the District (median 4 µg m-3) and Victoria (median 361 µg m-3 but up to 885 µg m-3). Broadly in agreement with other subway systems around the world, sampled LU PM2.5 comprised 47% iron oxide, 7% elemental carbon, 11% organic carbon, and 14% metallic and mineral oxides. Although a relationship between line depth and air quality inside the tube trains was evident, there were clear influences relating to the distance from cleaner outside air and the exchange with cabin air when the doors open. The passenger population-weighted exposure analysis demonstrated a method to identify stations that should be prioritised for remediation to improve air quality. CONCLUSION: PM2.5 concentrations in the LU are many times higher than in other London transport Environments. Failure to include this environment in epidemiological studies of the relationship between PM2.5 and health in London is therefore likely to lead to a large exposure misclassification error. Given the significant contribution of underground PM2.5 to daily exposure, and the differences in composition compared to urban PM2.5, there is a clear need for well-designed studies to better understand the health effects of underground exposure.


Asunto(s)
Contaminación del Aire , Contaminantes Atmosféricos , Monitoreo del Ambiente , Londres , Tamaño de la Partícula , Material Particulado
13.
Sci Rep ; 9(1): 11508, 2019 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-31395926

RESUMEN

The dispersion of an acoustic surface wave supported by a line of regularly spaced, open ended holes in an acrylic plate, is characterised by precise measurement of its localised acoustic fields. We illustrate the robust character of this surface wave and show its potential for control of sound by the acoustic waveguiding provided by a ring of regularly spaced holes. A single line of open-ended holes is shown to act as simple acoustic waveguide that can be readily manipulated to control the flow of sound.

14.
Ethn Dis ; 29(Suppl 1): 83-92, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30906154

RESUMEN

Implementation science has great potential to improve the health of communities and individuals who are not achieving health equity. However, implementation science can exacerbate health disparities if its use is biased toward entities that already have the highest capacities for delivering evidence-based interventions. In this article, we examine several methodologic approaches for conducting implementation research to advance equity both in our understanding of what historically disadvantaged populations would need-what we call scientific equity-and how this knowledge can be applied to produce health equity. We focus on rapid ways to gain knowledge on how to engage, design research, act, share, and sustain successes in partnership with communities. We begin by describing a principle-driven partnership process between community members and implementation researchers to overcome disparities. We then review three innovative implementation method paradigms to improve scientific and health equity and provide examples of each. The first paradigm involves making efficient use of existing data by applying epidemiologic and simulation modeling to understand what drives disparities and how they can be overcome. The second paradigm involves designing new research studies that include, but do not focus exclusively on, populations experiencing disparities in health domains such as cardiovascular disease and co-occurring mental health conditions. The third paradigm involves implementation research that focuses exclusively on populations who have experienced high levels of disparities. To date, our scientific enterprise has invested disproportionately in research that fails to eliminate health disparities. The implementation research methods discussed here hold promise for overcoming barriers and achieving health equity.


Asunto(s)
Equidad en Salud , Disparidades en Atención de Salud , Ciencia de la Implementación , Conducta Cooperativa , Humanos , Proyectos de Investigación , Investigadores , Poblaciones Vulnerables
15.
J Hosp Infect ; 101(4): 393-398, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30594611

RESUMEN

BACKGROUND: Healthcare worker (HCW) hand hygiene compliance is key to patient safety; however, compliance is suboptimal. Nevertheless hand hygiene compliance is not well studied in the long-term care setting. AIM: To apply a behaviour change framework, the Theoretical Domains Framework (TDF), to identify modifiable facilitators and barriers for HCW hand hygiene compliance in long-term care settings. METHODS: HCW hand hygiene compliance facilitators and barriers were examined using a questionnaire for HCWs from long-term care homes in Ontario, Canada. The questionnaire was informed by the TDF, which is based on a synthesis of constructs from a number of relevant psychological theories of behaviour change. FINDINGS: Barriers identified from the questionnaire aligned with the TDF domain environmental context and resources (time pressure, workload, and environmental controls). Facilitators identified from questionnaire results aligned with the TDF domains social/professional role and identity (it is what is expected of HCWs), and beliefs about consequences (risk of transmission of micro-organisms to self or others). CONCLUSION: There are several barriers to hand hygiene compliance that persist in long-term care. A behaviour change theory-informed framework such as the TDF can be helpful to identify those barriers. This study identified several key behavioural constructs aligned with the TDF that can be targeted when developing novel hand hygiene interventions.


Asunto(s)
Actitud del Personal de Salud , Adhesión a Directriz/estadística & datos numéricos , Higiene de las Manos/métodos , Higiene de las Manos/estadística & datos numéricos , Transmisión de Enfermedad Infecciosa de Profesional a Paciente/prevención & control , Cuidados a Largo Plazo , Utilización de Procedimientos y Técnicas , Conducta , Femenino , Instituciones de Salud , Humanos , Masculino , Ontario , Encuestas y Cuestionarios
17.
Rev Sci Instrum ; 89(5): 052101, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29864892

RESUMEN

A vessel for extraction and source plasma analyses is being used for Penning H- ion source development at the Rutherford Appleton Laboratory. A new set of optical elements including an einzel lens has been installed, which transports over 80 mA of H- beam successfully. Simultaneously, a 2X scaled Penning source has been developed to reduce cathode power density. The 2X source is now delivering a 65 mA H- ion beam at 10% duty factor, meeting its design criteria. The long-term viability of the einzel lens and 2X source is now being evaluated, so new diagnostic devices have been installed. A pair of electrostatic deflector plates is used to correct beam misalignment and perform fast chopping, with a voltage rise time of 24 ns. A suite of four quartz crystal microbalances has shown that the cesium flux in the vacuum vessel is only increased by a factor of two, despite the absence of a dedicated cold trap. Finally, an infrared camera has demonstrated good agreement with thermal simulations but has indicated unexpected heating due to beam loss on the downstream electrode. These types of diagnostics are suitable for monitoring all operational ion sources. In addition to experimental campaigns and new diagnostic tools, the high-performance VSim and COMSOL software packages are being used for plasma simulations of two novel ion thrusters for space propulsion applications. In parallel, a VSim framework has been established to include arbitrary temperature and cesium fields to allow the modeling of surface physics in H- ion sources.

19.
Appl Opt ; 56(29): 8201-8206, 2017 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-29047697

RESUMEN

This paper investigates numerically dual-grating dielectric laser-driven accelerators driven by a pulse-front-tilted (PFT) laser, which extends the interaction length and boosts the electrons' energy gain. The optical system necessary to generate PFT laser beams with an ultrashort pulse duration of 100 fs is also studied in detail. Through two-dimensional particle-in-cell simulations, we show that such a PFT laser effectively increases the energy gain by (91±25) % compared to that of a normally incident laser with a waist radius of 50 µm for a 100-period dual-grating structure.

20.
Internet Interv ; 8: 15-26, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28584734

RESUMEN

BACKGROUND: There is an ongoing need for effective and accessible preventive interventions for adolescent depression and substance abuse. This paper reports on a field trial of an online indicated preventive intervention, ProjectTECH, which is based on cognitive-behavioral therapy (CBT) techniques. The study aims to gather information about the feasibility and acceptability of this program. Secondary aims of this study were to examine the impact of the program on depression symptoms, perceived stress, positive affect, and substance use and to compare differences between groups that were led by a peer versus those that were led by a licensed clinician. METHODS: High school students (n = 39) were recruited primarily through social media advertisements, and assigned to four groups of 8-12 individuals to collaboratively participate in an 8 week peer network-based online preventive intervention which were led by a trained peer guide or a licensed clinician. Participants were provided with didactic lessons, CBT-based mood management tools, and peer networking features, and completed quantitative and qualitative feedback at baseline, midpoint, end of intervention, and 1 month follow up. RESULTS: The program attracted and retained users primarily from social media and was used frequently by many of the participants (system login M = 25.62, SD = 16.58). Participants rated the program as usable, and offered several suggestions for improving the program, including allowing for further personalization by the individual user, and including more prompts to engage with the social network. From baseline to end of intervention, significant decreases were observed in depressive symptoms and perceived stress (p's < .05). Significant increases in positive affect were observed from baseline to midpoint (p < .05) and no changes were observed in substance use, although the rate of substance use was low in this sample. While this study had low power to detect group differences, no consistent differences were observed between participants in a peer-led group and those in a clinician-led group. CONCLUSIONS: Results of this study indicates that ProjectTECH, an indicated preventive intervention for high school-aged adolescents, demonstrates both feasibility, acceptability, and short-term, longitudinal psychological benefits for participants. Future iterations of the program may benefit from close attention to user interface design and the continued use of trained peer support guides.

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